JPH0980149A - Radar apparatus for detecting distance and speed - Google Patents

Abstract

PROBLEM TO BE SOLVED: To detect a distance to a target object and a relative speed even with limited transmission power by removing an FM-AM (re-) conversion noise effectively with a simple structure. SOLUTION: This radar apparatus has a transmitting system to transmit a signal frequency modulated by a signal for modulation with a specified repeated frequency and a receiving system to receive a reflection wave signal as obtained when the modulation signal transmitted from the transmitting system is reflected on a target object 5 while mixing the reflection wave signal and the transmitted modulation signal from the transmitting system to detect a beat wave signal. A highpass filter 6 is provided to interrupt a signal having a modulation frequency component below a specified order modulation frequency component of the transmitted modulation signal for the beat wave signal detected in the receiving system and a distance/speed computation processing section 7 to determine a distance to the target object 5 and the relative speed by computation based on frequency information in the beat wave signal filtered by the high pass filter 6.

Description

Detailed Description of the Invention

(Technical Field of the Invention) Technical Field of the Invention Conventional Technology (FIGS. 30 to 36) Problems to be Solved by the Invention (FIGS. 34 to 36) Means for Solving the Problems (FIGS. 1 to 4) Embodiment (a) Description of the first embodiment (FIGS. 5 to 7) (b) Description of the second embodiment (FIG. 8) (c) Description of the third embodiment (FIGS. 9 to 13) d) Description of fourth embodiment (FIGS. 14 to 29)

[0002]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention transmits a signal frequency-modulated with a modulation signal having a predetermined repetition frequency,
This transmission signal (transmission modulation signal) receives the reflected wave signal reflected by the target object, and the beat wave signal is detected by mixing this reflected wave signal and a part of the transmission modulation signal to detect the target object. The present invention relates to a distance / velocity detecting radar device for detecting the distance and relative velocity.

[0003]

2. Description of the Related Art Conventionally, an FM-CW is a typical radar device for measuring a distance to a target and a relative velocity.
There is a radar device (frequency modulation continuous wave radar device). FIG. 30 is a block diagram showing the configuration of a conventional FM-CW radar device. The device shown in FIG. 30 has a modulation signal generator 101, a voltage control oscillator 102, an amplifier (AMP) 103 and a transmission system. A transmission antenna 104 is provided, and as a reception system, a reception antenna 106, a low noise amplifier (LNA) 107, a mixer 108, and a signal processing unit 109.
It is configured with. Reference numeral 105 denotes an automobile (target object) whose distance / relative speed is to be measured.

Here, in the transmission system, the triangular wave signal generator 101 has a triangular wave signal having a repetition frequency as shown in FIG. 31 (a) as a modulation signal for performing frequency modulation (FM modulation). (Center voltage v ₀ ) is generated, and the voltage control oscillator 102 uses the modulation signal generator 10
31 by performing FM modulation with the triangular wave signal from 1.
A signal having a waveform as shown in (b) is output as a transmission modulation signal (center frequency f ₀ ).

The amplifier 103 amplifies the transmission modulation signal to a required signal level, and the transmission antenna 104 transmits the transmission modulation signal amplified by the amplifier 103 to the space. On the other hand, in the receiving system, the receiving antenna 106 mainly receives the reflected wave signal in which the transmission modulation signal from the transmitting system is reflected by the automobile 105, and the low noise amplifier 107 amplifies the received reflected signal. It is a thing.

The mixer 108 mixes the reflected wave signal from the automobile 105 and a part of the transmission modulation signal from the voltage controlled oscillator 102 to obtain a beat wave signal of a reflection wave signal and a transmission modulation signal which will be described later. Is to detect. The signal processing unit 109 applies a fast Fourier transform (FFT: fast) to the beat wave signal obtained by the mixer 108.
By performing signal processing such as Fourier transform), the distance to the automobile 105 and the relative speed are obtained by required calculations. Therefore, the signal processing unit 109
As shown in FIG. 32, the FFT processing unit 110, the peak extraction unit 111, and the distance / speed calculation unit 112 are included.

[0007] Here, the FFT processing unit 110 is the mixer 1
The beat wave signal from 08 is subjected to fast Fourier transform, and the peak extraction unit 111 includes the FFT processing unit 1.
The distance frequency fr depending on the distance from the beat wave signal and the velocity frequency f depending on the relative velocity are calculated based on the calculation result in 10.
The peak values of the frequency information in the beat wave signal are extracted in order to detect d and d.

The distance / speed calculator 112 uses the distance frequency fr and the speed frequency fd obtained by the peak extractor 111 to calculate the distance and the relative speed with respect to the automobile 105 by the calculation described later. is there. The signal processing unit 109 is usually a DSP (Digital Signal Proc
essor) and other signal processors. With such a configuration, in the conventional FM-CW radar device, the voltage controlled oscillator 1 is generated by the triangular wave signal from the triangular wave signal generator 101.
The transmission modulation signal FM-modulated by 02 is amplified to a required signal level by the amplifier 103, and the transmission antenna 1
It is sent to the space through 04. Then, this transmission modulation signal is reflected by the automobile 105 and is received by the reception antenna 106.
Will be received at.

The reflected wave signal is amplified by the low noise amplifier 107 and mixed with a part of the transmission modulation signal from the voltage controlled oscillator 102 by the mixer 108. For example,
Now, assuming that a transmission modulation signal having a waveform (frequency) shown by the solid line in FIG. 33A is sent from the voltage control oscillator 102 of the transmission system, the automobile 105 shown by the broken line.
A signal that has been subjected to a delay time corresponding to the distance between and and a Doppler shift (fd) corresponding to the relative speed is received by the receiving antenna 106 as a reflected signal.

When the transmission signal (transmission modulation signal) and the reception signal (reflected wave signal) are mixed by the mixer 108, the frequency difference between the transmission signal and the reception signal is generated as shown in FIG. 33 (b). A beat wave signal representing (beat) is obtained and output to the signal processing unit 109. In the signal processing unit 109, the FFT processing unit 110 performs fast Fourier transform on the beat wave signal, and the peak extraction unit 111 extracts each peak value of the frequency information in the beat wave signal. As a result, the beat wave signal From the frequency component (hereinafter referred to as the beat frequency) fb of the car 1
The distance frequency fr depending on the distance to 05 and the velocity frequency fd depending on the relative velocity are detected.

Now, the center frequency of FM modulation is f ₀ , the frequency shift width (modulation width) is ΔF, and the repetition frequency of the triangular wave is f.
m, time is t, speed of light is c, distance to the car 105 is R,
When the relative speed is V, the frequency f _{T of} the transmission signal, the phase Φ _{T of} the transmission signal, the phase Φ _R of the reception signal, and the frequency f _{R of the} reception signal are respectively expressed as follows. f _T = f ₀ ± 2ΔF ・ fm ・ t ・ ・ (1) Φ _T = 2π (f ₀ ± ΔF ・ fm ・ t) ・ t ・ ・ (2) Φ _R = 2π [f ₀ ± ΔF ・ fm ・ ( t-2R / c)] · (t-2R / c) f R = (1 / 2π) · (dΦ R / dt) ·· (3) = f 0 · (1-2V / c) ± ΔF · fm -2 (t-2R / c)-(1-2V / c)-(4) When the transmission signal and the reception signal are mixed by the mixer 108, the beat frequency fb is fb = (4.ΔF・ Fm / c) ・ R ± 2f ₀ (V / C) (5) The first term of this equation (5) is the distance frequency fr, the second term
Since the term is the speed frequency fd, fr = (4 · ΔF · fm / c) · R (6) fd = 2f ₀ (V / C) (7) is obtained.

That is, as described above, in the signal processing unit 109, the FFT processing unit 110 and the peak extraction unit 111 perform the fast Fourier transform and the peak extraction process on the beat frequency fb represented by the equation (5). As a result, the distance frequency fr and the velocity frequency fd expressed by the equations (6) and (7) are detected. Then, the distance / speed calculator 112 performs a calculation process based on the equations (6) and (7) to obtain the distance R to the automobile 105 and the relative speed V.

In the FM-CW radar device described above, a part of the transmission modulation signal (FM modulation wave) from the transmission system is input to the mixer 108 to be mixed with the reception signal. When the amplitude of the transmission modulation signal changes due to the frequency characteristics of the voltage controlled oscillator 102 and the amplifier 103, the mixer 108 causes a harmonic frequency component f called FM-AM conversion noise as shown in FIG.
m, 2fm, 3fm, ... Appear near the frequency of the original received signal.

As a result, in the FM-CW radar device described above, the FM-AM conversion noise and the frequency information of the original received signal cannot be separated, and the S / N ratio deteriorates, and the distance to the target and A large error will occur in the detection of the relative speed. Therefore, conventionally, for example, as shown in FIG. 35, the low-noise amplifier 107 of the receiving system is provided with a modulation frequency f of the transmission signal.
A signal having a frequency fsw that is considerably larger than m is input, and the modulation frequency f is applied to the output of the low noise amplifier 107.
By performing modulation at a frequency fsw that is considerably larger than m, as shown in FIG. 36 (a), the output of the original received signal is converted into the above harmonic frequency components fm, 2f.
There is also a device that is far away from m, 3fm, ..., And can improve the S / N ratio by minimizing the influence of FM-AM conversion noise.

In FIG. 35, reference numeral 113 is a high-pass filter (HPF), 114 is a mixer, which cuts frequency components equal to or lower than the frequency component fsw input to the low noise amplifier 107. b)
The spectrum of the received signal (reflected signal) as shown in (1) is obtained.

[0016]

However, even in such a conventional FM-CW radar device as described above, the transmission modulation signal from the transmission system slightly leaks to the low noise amplifier 107 and undergoes AM modulation. (A), FIG.
As shown in FIG. 6 (b), F is still near the frequency fsw.
Harmonic frequency component fsw called M-AM reconversion noise
. ± .fm, fsw. ± .2fm, fsw. ± .3fm, ...

These harmonic frequency components fsw ± fm,
The size of fsw ± 2fm, fsw ± 3fm, ...
As shown in FIG. 34, the harmonic frequency components fm, 2fm,
It is smaller than 3 fm, and the reception S / N ratio is considerably improved, but when trying to catch a target at a farther distance, this FM-AM reconversion noise cannot be ignored. The present invention has been devised in view of such problems, and effectively removes FM-AM (re) conversion noise with a simple configuration, so that the distance to the target and the relative speed can be reduced even with a small transmission power. An object of the present invention is to provide a radar device for distance / velocity detection, which can detect with high accuracy.

[0018]

FIG. 1 is a block diagram of the principle of the first invention. In FIG. 1, 1 is a voltage-controlled oscillator, 2 is a transmitting antenna, and 3 is a target object of distance / speed detection. Reference numeral 4 is a receiving antenna, 5 is a mixer, 6 is a high-pass filter, and 7 is a distance / speed calculation processing unit. Here, the voltage controlled oscillator 1 is for generating a signal that is frequency-modulated with a modulation signal having a predetermined repetition frequency, and the transmission modulation signal generated by this voltage controlled oscillator 1 is transmitted from the transmission system through the transmission antenna 2. It is designed to be output as a transmission modulation signal of.

The receiving antenna 4 mainly receives a reflected wave signal in which the transmission modulation signal from the transmitting system is reflected by the target 3, and the mixer 5 receives the reflected wave signal received by the receiving antenna 4. The signal and the transmission modulation signal from the transmission system are mixed, and the mixer 5 detects the reflected wave signal and the beat wave signal of the transmission modulation signal.

The high-pass filter 6 cuts off a signal having a modulation frequency component equal to or lower than a predetermined order modulation frequency component of the transmission modulation signal from the beat wave signal detected by the receiving system. The unit 7 determines the distance to the target 3 and the target 3 based on the frequency information in the beat wave signal filtered by the high-pass filter 6.
And the relative velocity between the observer and the observer are calculated.

With the above-described structure, in the above-described distance / speed detection radar device, a signal frequency-modulated with a modulation signal having a predetermined repetition frequency is transmitted from the voltage control oscillator 1 through the transmission antenna 2 from the transmission system. The reception antenna 4 receives a reflection signal which is output as a modulation signal and which is the transmission modulation signal from this transmission system reflected by the target object 3.

The reflected signal and the transmission modulation signal from the transmission system are mixed by the mixer 5,
Beat wave signals of the reflected wave signal and the transmission modulation signal are detected. Further, this beat wave signal is passed through the high pass filter 6
By passing through, the signal having a modulation frequency component equal to or lower than the predetermined order modulation frequency component of the transmission modulation signal is blocked.

As a result, in the distance / velocity calculation processing unit 7, the frequency cut off by the high-pass filter 6 for the modulation frequency component that occurs near the frequency component of the received signal (reflected signal) and makes it difficult to extract the frequency information of the received signal. Based on only the information, the distance to the target 3 and the relative speed between the target 3 and the observer can be calculated (above, claim 1).

Next, FIG. 2 is a block diagram showing the principle of the second invention. The distance / speed detecting radar device shown in FIG. 2 has a voltage controlled oscillator 1 similar to that described in FIG.
An FM-CW radar device configured to include a transmitting antenna 2, a receiving antenna 4, a mixer 5, a high-pass filter 6, and a distance / velocity calculation processing unit 7, and a short-distance type different from the FM-CW radar device. The radar device 8 is provided.

In FIG. 2, reference numeral 9 is a transmission / reception antenna for the radar device 8, and 10 is a switching unit for selectively using the FM-CW radar device and the short-distance radar device 8. With such a configuration, even in the above-described distance / speed detection radar device, as in the device shown in FIG.
In the distance / velocity calculation processing unit 7 of the M-CW radar device, the target object 3 is generated based on only the frequency information in the beat wave signal in which the high-pass filter 6 blocks the modulation frequency component equal to or lower than the predetermined order modulation frequency component of the transmission modulation signal. The distance to and the relative speed between the target 3 and the observer can be calculated.

Since the radar device shown in FIG. 2 is further provided with a short range radar device 8 of a type different from the FM-CW radar device described above,
In the FM-CW radar device, when the high-pass filter 6 blocks the modulation frequency component equal to or lower than the predetermined order modulation frequency component of the transmission modulation signal, the frequency information when the distance to the target is short is lost. In addition, the distance to the target object 3 and the relative speed between the target object 3 and the observer can be obtained by using the short-distance radar device 8 (above, claim 2).

Further, FIG. 3 is a block diagram of the principle of the third invention. The distance / speed detection radar device shown in FIG. 3 has a voltage controlled oscillator 1 and a transmitter similar to those described in FIG. In addition to the antenna 2, the receiving antenna 4, and the mixer 5, the distance / speed calculation processing unit 7A and the storage unit 11 are provided. Here, the storage unit 11 stores the FM-AM conversion noise information output in a state where the reflected wave signal from the target object 3 is not received, and the distance / velocity calculation processing unit 7A is shown in FIG. In the same manner as described above, the target object 3 is based on the frequency information of the beat wave signal detected by the receiving system.
The distance to the target object 3 and the relative speed between the target 3 and the observer are calculated, and in this case, the distance / speed calculation processing unit 7A uses the FM-A stored in the storage unit 11.
The calculation is performed after the M conversion noise information is subtracted.

With such a configuration, in the above-described radar apparatus for detecting distance / speed, the FM-AM converted noise information output in a state where the reflected wave signal from the target 3 is not received is
It is stored in the storage unit 11. As a result, in the distance / speed calculation processing unit 7A, the FM stored in the storage unit 11 is stored.
The distance to the target 3 and the distance between the target 3 and the observer based on only the frequency information obtained by subtracting the FM-AM converted noise information in the beat wave signal detected by the receiving system using the AM converted noise information. The relative speed and the relative speed can be calculated (above, claim 3).

Further, as shown in FIG. 3, the above-mentioned radar apparatus for distance / speed detection is provided with a transmission / reception signal blocking means 12 capable of blocking the transmission / reception signal transmission / reception with the transmission system and the reception system. The FM-AM conversion noise information is stored in the storage means 11 in a state where the transmission / reception signal blocking means 12 blocks the exchange of the transmission / reception signal with the outside, and the FM transmission / reception signal is exchanged with the outside. It is configured to perform the calculation for obtaining the above distance / relative velocity in consideration of the AM conversion noise information.

Thus, first, the transmission / reception signal blocking means 1
The FM-AM conversion noise information is stored in the storage means 11 in a state where the transmission / reception signal exchange with the outside is blocked by 2, and the FM-AM conversion noise information is exchanged with the transmission / reception signal exchange with the outside. The calculation for obtaining the distance / relative velocity is performed in consideration of the above (above, claim 4). Here, specifically, the transmission / reception signal blocking means 12 is composed of switches provided in the transmission system and the reception system, respectively, and at least the switch provided in the reception system among these switches is in the OFF state and the storage means is stored. 11 to FM-AM
The conversion noise information is stored, and the calculation for obtaining the distance / relative velocity is performed in consideration of the FM-AM conversion noise information while the switches are turned on.

As a result, the transmission / reception signal blocking means 12 is
If the switch is provided in each of the transmission system and the reception system, at least one of these switches provided in the reception system is in the off state and the FM- is stored in the storage means 11.
The AM conversion noise information can be stored, and the calculation for obtaining the distance / relative velocity can be performed in consideration of the FM-AM conversion noise information in the ON state of these switches.

The transmission / reception signal blocking means 12 may be composed of attenuators provided in the transmission system and the reception system, respectively. In this case, at least the attenuator provided in the reception system among these attenuators. The FM-AM conversion noise information is stored in the storage means 11 in the signal attenuation state according to the above, and the distance / relative velocity is calculated in consideration of the FM-AM conversion noise information in the signal non-attenuation state of these attenuators. Will be applied.

Then, in this way, the transmission / reception signal blocking means 1
If 2 is composed of an attenuator provided in each of the transmission system and the reception system, at least the attenuator provided in the reception system among these attenuators is in a signal attenuated state, and the storage means 1
1 can store the FM-AM conversion noise information, and in the signal non-attenuated state of these attenuators, the calculation for obtaining the distance / relative velocity can be performed in consideration of the FM-AM conversion noise information ( As described above, claim 6).

Further, the transmission / reception signal blocking means 12 is
The transmission system and the reception system may be configured with changeover switches capable of switching between the antenna side and the terminator side, respectively. In this case, at least one of these changeover switches is a terminator using a changeover switch provided in the reception system. The FM-AM conversion noise information is stored in the storage means 11 in the switching state to the side, and the distance / relative speed in consideration of the FM-AM conversion noise information in the switching state to the antenna side by these changeover switches. To calculate.

As described above, if the transmission / reception signal blocking means 12 is constituted by the changeover switch capable of switching between the antenna side and the terminator side in the transmission system and the reception system, at least the reception system is provided among these changeover switches. In the state of switching to the terminator side by the selected changeover switch, F is stored in the storage means 11.
The M-AM conversion noise information can be stored, and in the state of switching to the antenna side by these changeover switches, FM-
The calculation for obtaining the distance / relative velocity can be performed in consideration of the AM conversion noise information (above, claim 7).

Next, FIG. 4 is a block diagram of the principle of the fourth invention. The radar apparatus for distance / speed detection shown in FIG. 4 also has a voltage controlled oscillator 1 similar to that described in FIG.
In addition to the transmitting antenna 2, the receiving antenna 4 and the mixer 5, the distance / speed calculation processing section 7B is provided. Here, the distance / speed calculation processing unit 7B also calculates the distance to the target 3 and the relative speed between the target 3 and the observer based on the frequency information of the beat wave signal detected by the receiving system. In this case, the calculation is performed after removing the information about the modulation frequency component of the transmission modulation signal.

As a result, also in this distance / speed detection radar device, the distance / speed calculation processing section 7B determines the distance to the target 3 and the target based on the frequency information of the beat wave signal detected by the receiving system. 3 and the relative velocity between the observer and the observer can be obtained by calculation. In this case, the calculation is performed after removing the information about the modulation frequency component of the transmission modulation signal (above, claim 8). .

The apparatus shown in FIG. 4 has a transmission system,
It may be configured to be able to transmit a signal that is frequency-modulated with a selected predetermined modulation signal among a plurality of modulation signals having different repetition frequencies, and the frequency shift amount of the transmission modulation signal can be made variable. May be configured as
Further, the transmission center frequency for the transmission modulation signal may be variable.

Then, if a signal frequency-modulated by a predetermined modulation signal selected from a plurality of modulation signals having different repetition frequencies is transmitted, the modulation frequency component of the transmission modulation signal and the reception signal (reflection signal) It is possible to deviate the matching with the frequency information of 1 by a required amount, and thus it is possible to prevent the frequency information of the received signal from being removed together with the information about the modulation frequency component of the transmitted modulated signal.

Similarly, even when a signal with a variable frequency shift amount for a transmission modulation signal is transmitted, or when a signal with a transmission center frequency for a transmission modulation signal is variable, the transmission modulation signal is similarly changed. Since it is possible to shift the matching between the modulation frequency component of 1 and the frequency information of the received signal by a required amount, it is possible to prevent the frequency information of the received signal from being removed together with the information about the modulation frequency component of the transmitted modulated signal ( As described above, claims 9 to 11).

By the way, specifically, the above-mentioned distance / velocity calculation processing unit 7B determines the distance to the target object 3, the target object 3, and the observer based on the frequency information of the beat wave signal detected by the receiving system. When calculating the relative speed and the relative speed of, the calculation is performed using past data. As a result, in the radar device shown in FIG. 4, even if the frequency information of the reception signal is removed together with the information about the modulation frequency component of the transmission modulation signal, the distance / velocity calculation processing unit 7B uses the past data. The distance to the target object 3 and the relative speed between the target object 3 and the observer can be obtained by performing the calculation using the above (the above is the twelfth aspect).

Here, as the past data, the information on the distance and the relative velocity obtained in the previous calculation is used (claim 13), but in the previous calculation and the second calculation. The information on the distance and the relative speed obtained respectively may be used (claim 14). In addition, the distance / speed calculation processing unit 7B
When calculating the distance to the target object 3 and the relative speed between the target object 3 and the observer by calculation based on the frequency information of the beat wave signal detected by the receiving system, for signals above a predetermined signal level, Alternatively, the information removal processing may be prohibited.

As a result, the distance / speed calculation processing unit 7
In B, when the reflected signal in the beat wave signal is equal to or lower than a predetermined signal level, only the frequency information obtained by removing the information of the modulation frequency component of the transmission modulated signal generated near the frequency of the reflected signal is used as the target object. The distance to 3 and the relative speed between the target 3 and the observer can be calculated (the above is the fifteenth aspect).

[0044]

Embodiments of the present invention will be described below with reference to the drawings. (A) Description of First Embodiment FIG. 5 is a block diagram showing the configuration of an FM-CW radar device (range / speed detection radar device) according to the first embodiment of the present invention. The FM-CW radar device has a triangular wave signal generator 21, a voltage controlled oscillator (VCO) 22, an amplifier (AMP) 23 and a transmitting antenna 24 as a transmitting system, and a receiving antenna 26, a low antenna as a receiving system. Noise amplifier (LNA) 27, mixer (MI
X) 28, a high-pass filter (HPF), and a signal processing unit 30. It should be noted that what is indicated by reference numeral 25 is an automobile (target) whose distance / speed is to be detected.

Here, in the transmission system, the triangular wave signal generator 21 has a predetermined repetition frequency f for performing frequency modulation (FM modulation) as shown in FIG. 31 (a), for example.
The triangular wave signal generator 2 generates a triangular wave signal (modulation signal) having m.
A signal obtained by frequency-modulating (FM-modulating) the triangular wave signal from 1 [center frequency f ₀ : see FIG. 31B] is output as a transmission modulation signal.

Further, the amplifier 23 includes a voltage controlled oscillator 22.
Is amplified to a predetermined signal level, and the transmission antenna 24 sends the transmission modulated signal from the amplifier 23 to space, particularly to the automobile 25. On the other hand, in the receiving system, the receiving antenna 2
Reference numeral 6 is for receiving the reflected wave signal in which the transmission modulation signal transmitted from the transmission antenna 24 of the transmission system is reflected by the automobile 25, and the low noise amplifier 27 is used for the reflected wave signal (hereinafter, referred to as a reflected wave signal received by the receiving antenna 26. Amplitude modulation (AM modulation) is applied to a received signal), and the mixer 28 uses the reflected wave signal from the low noise amplifier 27 and the transmission modulation signal from the voltage controlled oscillator 21 of the transmission system. The beat wave signals of the reflected wave signal and the transmission modulation signal are detected by mixing some of them with each other.

The high-pass filter 29 detects the beat wave signal detected by the mixer 28 as shown in FIG.
As shown in FIG. 7B, harmonic frequency components (modulation frequency components) fm, 2fm, 3 generated near the frequency of the received signal.
Of the fm, ..., For example, a harmonic frequency component fm having a frequency component of the fifth harmonic frequency component 5 fm or less.
It blocks ~ 5 fm. Note that, normally, the data of the received signal that appears in the vicinity of the harmonic frequency components fm to 5fm in this manner is short-distance data when the distance to the automobile 25 is about 1 m.

The signal processing unit (distance / velocity calculation processing unit) 30 performs signal calculation processing such as fast Fourier transform on the beat wave signal from the high-pass filter 29 to obtain an automobile having the beat wave signal. Frequency information (distance frequency fr) dependent on the distance to 25 and frequency information (speed frequency fd) dependent on the relative speed,
Based on this, the distance to the car 25 and the car 25
And the relative velocity between the observer and the observer are calculated.

Therefore, as shown in FIG. 6, the signal processing unit 30 performs F Fourier transform on the input data (beat wave signal that has passed through the high pass filter 29).
The FT processing unit 311, a peak extraction unit 312 that obtains the distance frequency fr and the velocity frequency fd described above based on the calculation processing results in the FFT processing unit 311, and the distance frequency fr and the velocity frequency obtained by the peak extraction unit 312. A distance / speed calculation unit 313 for calculating the above distance and relative speed based on fd is configured.

In the FM-CW radar device as the first embodiment of the present invention configured as described above, the signal frequency-modulated by the triangular wave having the repetition frequency fm from the triangular wave signal generator 21 is Voltage controlled oscillator 22 to amplifier 2
Transmit antenna 2 after being amplified to the required signal level in 3
4 is output as a transmission modulation signal, and the reflection wave signal obtained by reflecting the transmission modulation signal on the automobile 25 is received by the reception antenna 26.

The reflected wave signal and a part of the transmission modulation signal from the voltage control oscillator 22 of the transmission system are mixed by the mixer 28.
The beat wave signal of the reflected wave signal and the transmission modulation signal is detected by being mixed with. Further, the beat wave signal passes through the high-pass filter 29, and as shown in FIGS. 7 (a) and 7 (b), harmonic frequency components fm, 2fm, generated near the frequency of the received signal,
Of 3 fm, ..., 5th or lower frequency components (harmonic frequency components fm to 5 fm) are blocked.

As a result, in the signal processing unit 30, the high-pass filter 29 cuts off the harmonic frequency components fm to 5fm which occur near the frequency components of the received signal and make it difficult to extract the frequency information of the received signal. Based on only the frequency information of the received signal in the beat wave signal, the FFT processing unit 311 performs fast Fourier transform processing and peak extraction unit 31.
The extraction processing of the distance frequency fr and the velocity frequency fd by 2 is performed.

Then, the distance / velocity calculator 313 performs arithmetic processing on the obtained distance frequency fr and speed frequency fd based on the above-mentioned equations (6) and (7), whereby the automobile 25 The distance to and the relative speed between the vehicle 25 and the observer are obtained. Thus, the first aspect of the present invention
According to the FM-CW radar device (the distance / velocity detection radar device) as the embodiment, the fifth-order or less generated in the vicinity of the frequency of the received signal (reflected wave signal) is provided by the extremely simple configuration of providing the high-pass filter 29. Since the distance to the automobile (target) 25 and the relative speed can be obtained after blocking the modulation frequency component (harmonic frequency component fm to 5fm) of a predetermined order or less), the reception S / of the radar device can be obtained.
The N ratio can be significantly improved, and thus, even if the reception state of the reflected wave signal from the automobile 25 is poor, the distance to the automobile 25 and the relative speed can be detected with high accuracy.

Further, even if the transmission power of the transmission modulation signal is small, the above-mentioned distance and speed can be detected with high accuracy. Therefore, with the same transmission power, the distance and the relative speed to the target object at a longer distance can be obtained. Can be detected. (B) Description of Second Embodiment FIG. 8 is a block diagram showing the configuration of a distance / speed detection radar device according to a second embodiment of the present invention.
The radar device shown in FIG.
The transmission system includes a triangular wave signal generator 21, a voltage controlled oscillator (VCO) 22, an amplifier (AMP) 23 and a transmission antenna 24, and a reception system includes a reception antenna 26, a low noise amplifier (LNA) 27, and a mixer ( MIX) 28, a high-pass filter (HPF), and a signal processing unit (distance / velocity calculation processing unit) 30, and an infrared ray for short range different from the FM-CW radar device. A radar device 31 is provided.

With such a configuration, in the radar apparatus shown in FIG. 8 as well, in the signal processing unit 30 of the FM-CW radar apparatus, the reflected wave signal (received signal) from the automobile 25 is received.
After the harmonic frequency components fm to 5fm, which are generated in the vicinity of the frequency components of the above and which make it difficult to extract the frequency information of the received signal, are blocked by the high-pass filter 29 [FIG. 7 (a), FIG.
(B)], based on only the frequency information of the received signal in the beat wave signal, the fast Fourier transform processing by the FFT processing unit 311, the extraction of the distance frequency fr and the speed frequency fd by the peak extraction unit 312, the distance / speed calculation unit 31
By performing the calculation process according to 3, the distance to the automobile 25 and the relative speed between the automobile 25 and the observer can be calculated.

By the way, in this case, when the high frequency filter 29 cuts off the harmonic frequency components fm to 5 fm as described above, the frequency information of the received signal when the distance between the automobile 25 and the observer is short is also included. It will be cut off, and short-range data will be lost. Therefore, in the present embodiment, as shown in FIG.
An infrared radar device 31 for a short distance different from the W radar device is provided, and in the FM-CW radar device, the frequency information of the reflected wave signal in the beat wave signal is lost,
Range where the distance and speed with the car 25 cannot be measured (short distance)
With regard to (2), the distance and speed with respect to the automobile 25 are obtained by using the infrared radar device 31 by switching by the switching unit 33.

As described above, according to the distance / velocity detecting radar apparatus as the second embodiment of the present invention, the short-range infrared radar apparatus 31 is added to the FM-CW radar apparatus described in FIG. With such a simple configuration, it is possible to easily supplement the lack of short-distance data, and there is an advantage that the necessary detection range of distance and relative speed can be easily secured.

Although the infrared radar device 31 is used as the short range radar device in the distance / speed detection radar device of this embodiment, the present invention is not limited to this, and the FM-CW radar device is used. It may be configured using another short-range radar device of a type different from. (C) Description of Third Embodiment FIG. 9 is a block diagram showing the configuration of an FM-CW radar device (distance / speed detection radar device) according to a third embodiment of the present invention. As with the first embodiment, the FM-CW radar device also has a triangular wave signal generator 21, a voltage controlled oscillator 22, and an amplifier (AMP) 2 as a transmission system.
3 and a transmitting antenna 24, and a receiving system includes a receiving antenna 26, a low noise amplifier (LNA) 27, and a mixer (MIX) 28.

The FM-CW radar device according to the present embodiment is provided with a signal processing unit 30A and a memory 35 in addition to the above-mentioned structure, and switches (SW) 36A and 36B for the transmission system and the reception system, respectively. Is provided. Here, the memory (storage means) 35 is used for the automobile 2
5, the modulation frequency component of the transmission modulation signal (frequency fm) generated in the beat wave signal from the mixer 28 obtained by the signal processing unit 30A described later in a state where the reflected wave signal from 5 is not received, that is, the above-mentioned harmonic frequency component ( FM-AM conversion noise information) fm, 2fm, 3fm, ... Are stored, and each switch (transmission / reception signal blocking means) 3 is stored.
6A and 36B are capable of blocking the exchange of transmission / reception signals with the outside by switching the respective on / off states.

Also in this embodiment, the signal processing section 30A determines the distance to the vehicle (target) 25 and the vehicle 2 based on the frequency information of the beat wave signal detected by the receiving system.
5 and the relative speed of the observer are obtained by calculation such as fast Fourier transform.
At least when the switch 36A is in the OFF state (when the reflected wave signal from the automobile 25 is not received), only the FM-AM conversion noise information that appears in the beat wave signal is stored in the memory 35, and the switches 36A and 36B are in the ON state. Then
FM-AM conversion noise information fm, 2fm, 3fm stored in the memory 35 from the frequency information in the beat wave signal.
... is subtracted, and then the distance and speed with respect to the automobile 25 are calculated.

For this reason, the signal processing unit 30A is similar to that shown in FIG.
As shown in FIG. 0, in addition to the FFT processing unit 311, the peak extraction unit 312, and the distance / speed calculation unit 313 similar to those shown in FIG. 6 in the first embodiment, the noise subtraction unit 314 is also provided.
In the off state of the receiving system switch 36A, the F detected by the peak extracting unit 312 is
The M-AM conversion noise information fm, 2fm, 3fm, ... Is stored in the memory 35, and when the switches 36A, 36B are in the ON state, the FM-AM conversion noise information fm, 2fm, 3fm stored in the memory 35. , Are read by the noise subtraction unit 314.

In the noise subtraction unit 314, FM-AM conversion noise information generated near the frequency of the received signal in the beat wave signal subjected to the fast Fourier transform by the FFT processing unit 311 while the switches 36A and 36B are on. fm, 2fm, 3fm, ... Are removed by reading and subtracting the FM-AM conversion noise information stored in the memory 35 in advance.

With such a configuration, in the FM-CW radar device according to the present embodiment, first, at least the receiving system switch 36A is turned off so that the reflected wave signal from the automobile 25 is not received, and the voltage controlled oscillator is received. FM-AM resulting from the transmission modulation signal (frequency fm) from 22
The beat wave signal having only the converted noise information fm, 2fm, 3fm, ... Is output from the mixer 28 to the signal processing unit 30A.

Then, in the signal processing unit 30A, the FFT processing unit 311 performs fast Fourier transform processing on the beat wave signal, and the calculation result is written and stored in the memory 35. After that, each switch 36A, 36
When B is turned on, the reflected wave signal of the transmission modulation signal transmitted from the transmission antenna 24 reflected by the automobile 25 is received by the reception antenna 36A, and is output to the mixer 28 via the low noise amplifier 27.

This reflected wave signal is mixed with a part of the transmission modulation signal output from the voltage controlled oscillator 22 by the mixer 28, and frequency information (distance frequency fr, speed) depending on the distance to the automobile 25 and the relative speed is obtained. A beat wave signal including the frequency fd) is obtained and output to the signal processing unit 30A. Then, in the signal processing unit 30A, the FFT processing unit 311 and the peak extraction unit 312 perform processing such as fast Fourier transform on each of the beat wave signals. In this case as well, the solid line in FIG. As shown in, the FM-AM conversion noise information fm, 2fm, 3fm, which results from mixing a part of the transmission modulation signal by the mixer 28 near the frequency of the reception signal (reflected wave signal).
・ ・ Has occurred.

Therefore, the noise subtraction unit 314 is used by the switch 3
FM-A stored in the memory 35 in advance in the 6A off state
The M-converted noise information fm, 2fm, 3fm, ... Is read and the FM-AM converted noise information fm, 2f generated near the frequency of the received signal as indicated by the broken line in FIG.
By subtracting m, 3fm, ... In vector, as shown in FIG. 11B, FM-AM conversion noise information fm, 2fm, 3fm ,.
Is removed.

After that, as described in the first embodiment, the distance / speed calculation unit 313 determines that the vehicle 25 is in accordance with the distance frequency fr and the speed frequency fd in the beat wave signal obtained through the peak extraction unit 312. The distance and the relative speed are calculated. Thus, according to the FM-CW radar device (distance / speed detection radar device) as the third embodiment of the present invention, the vehicle (target object) 25
FM- output without receiving the reflected wave signal from
The AM conversion noise information fm, 2fm, 3fm, ... Is stored in the memory (storage means) 35 in advance, and this memory 2 is stored.
5, FM-AM conversion noise information fm, 2fm,
3 fm, ..., FM-AM conversion noise information fm, 2 fm, 3 in the beat wave signal detected by the receiving system.
Based on only the frequency information minus fm, ...
Since the distance to the automobile 25 and the relative speed can be obtained, the reception S / N ratio of the device can be greatly improved, and thus the above-mentioned distance / speed with high accuracy and low power consumption can be obtained. In addition to being able to detect, the distance and speed can be easily detected even when the receiving condition of the device is not good.

(C-1) Description of First Modification of Third Embodiment FIG. 12 shows F as a first modification of the third embodiment of the present invention.
FIG. 13 is a block diagram showing a configuration of an M-CW radar device (a radar device for distance / speed detection). The device shown in FIG. 12 is a switch 36A, 36B in the device shown in FIG.
Instead of the variable attenuator (ATT) 37A, 3
7B is used.

Here, each of the variable attenuators (transmission / reception signal blocking means) 37A, 37B puts each of them into a signal attenuation state, so that the transmission / reception signal is exchanged with the outside like the switches 36A, 36B. It can be blocked. The components other than the variable attenuators 37A and 37B are the same as those described above with reference to FIG.

With such a configuration, even in the FM-CW radar device according to this modification, at least the variable attenuator 37A of the receiving system is adjusted to a sufficient attenuation level to bring it into a signal attenuation state, so that the reflection from the automobile 25 is reflected. In the state where no wave signal is received, only the FM-AM conversion noise information fm, 2fm, 3fm, ... Caused by the transmission modulation signal (frequency fm) from the voltage controlled oscillator 22 is stored in the memory 35 in advance in this state. Incidentally, each of these variable attenuators 37A, 3
FM-A in the beat wave signal detected by the reception system by the signal processing unit 30A in the signal non-signal attenuation state of 7B.
The distance to the automobile 25 and the relative speed in consideration of the M conversion noise information fm, 2fm, 3fm, ... Can be calculated.

Therefore, the FM-CW radar device according to this modification can also obtain the same effects or advantages as the device shown in FIG. (C-2) Description of Second Modification of Third Embodiment FIG. 13 shows F as a second modification of the third embodiment of the present invention.
It is a block diagram showing a configuration of an M-CW radar device.
In the device shown in FIG. 13, instead of the switches 36A and 36B in the device shown in FIG. 9, the antennas 24 and 26 and the terminators 39A and 3 are respectively provided in the transmission system and the reception system.
Changeover switches 38A, 38 that can be switched to the 9B side
B is provided. Also in this modification, the changeover switches 38A and 38B and the terminators 39A and 39 are also included.
Each component other than B is the same as that described above with reference to FIG.

Here, the changeover switches 38A and 38B
Also, by switching to the terminators 39A and 39B, respectively, like the above-mentioned switches 36A and 36B, it is possible to interrupt the exchange of transmission / reception signals with the outside. Terminators 39A, 39B
By switching each of the changeover switches 38A and 38B to the side, impedance matching of the circuit is achieved, and a signal reflection phenomenon or the like is suppressed to obtain stable circuit operation.

With such a configuration, even in the FM-CW radar device according to the present modification, at least the reception system changeover switch 38A is switched to the terminator 39A side so that the voltage of the reflected wave signal from the automobile 25 is not received. FM-AM conversion noise information fm, 2fm, 3f caused by the transmission modulation signal (frequency fm) from the controlled oscillator 22.
.. are stored in the memory 35 in advance, and the FM in the beat wave signal detected in the reception system by the signal processing unit 30A in the signal non-signal attenuation state of each of the variable attenuators 37A and 37B. -AM conversion noise information fm, 2f
It is possible to calculate the distance and relative speed with respect to the automobile 25 in consideration of m, 3fm, ....

Therefore, the FM-CW radar device according to this modification can obtain the same effects and advantages as those of the device shown in FIG. 9, and also the changeover switches 38A and 38B.
By switching to the terminators 39A and 39B, respectively, circuit impedance matching can be achieved even when the reflected wave signal from the automobile 25 is not received, so that the FM-AM conversion noise information fm,
2 fm, 3 fm, ... Can be stored in the memory 35.

(D) Description of Fourth Embodiment FIG. 14 is a block diagram showing the configuration of an FM-CW radar device (range / speed detection radar device) according to a fourth embodiment of the present invention. The device shown in FIG. 14 also has, as a transmission system, a triangular wave signal generator 21, a voltage controlled oscillator 22, an amplifier (AMP) 23, and a transmission antenna 24, which are similar to those described in the first embodiment.

On the other hand, the receiving system has the same receiving antenna 26 and low noise amplifier (L) as those shown in the first embodiment.
In addition to having a NA) 27 and a mixer (MIX) 28, it has a signal processing unit 30B and a memory 35A. Here, the signal processing unit (distance / speed calculation processing unit) 35
Also in the present embodiment, A calculates the distance to the vehicle (target) 25 and the relative speed between the vehicle 25 and the observer based on the frequency information of the beat wave signal detected by the mixer 28 of the receiving system. In this embodiment, the harmonic frequency component (modulation frequency component) of the transmission modulation signal (frequency fm) from the voltage control oscillator 22 of the transmission system is obtained at this time.
The operation is performed after removing the information about fm, 2fm, 3fm, ....

That is, as shown in FIG. 15, the signal processing unit 30B has an FFT processing unit 311, a peak extraction unit 312, and a distance / speed calculation unit 313 which are similar to those shown in FIG. 6 in the first embodiment. In addition to memory 3
5A, a comparator (COMP) 315, a data latch unit 316, and a harmonic wave removing unit 317.

Here, the memory 35A includes the peak extraction unit 3
The frequency information of the harmonic frequency components fm, 2fm, 3fm, etc. in the beat wave signal obtained in 12 is stored in advance, and the comparator 315 stores the received signal (reflected wave signal) in the beat wave signal at the present time. It is determined whether or not the frequency information of) matches the frequency information of the harmonic frequency components fm, 2fm, 3fm, ... Prestored in the memory 35A.

Further, in the data latch section 316, as a result of the judgment by the comparator 315, the frequency information of the received signal at the present time is the frequency of the harmonic frequency components fm, 2fm, 3fm ... Which are prestored in the memory 35A. If it matches the information, the data is latched so that the subsequent arithmetic processing is not performed based on the frequency information obtained by the peak extraction unit 312 at that time, while if it does not match, the peak extraction is performed at that time. This frequency information is output to the distance / speed calculation unit 313 so that the subsequent arithmetic processing is performed based on the frequency information obtained by the unit 312.

Further, the harmonic wave removing unit 317 uses the memory 3 among the frequency information output from the data latch unit 316.
Harmonic frequency components fm, 2f stored in advance in 5A
The frequency information of m, 3fm ... Is removed.
That is, when the frequency information of the reflected wave signal from the automobile 25 matches the frequency components of the harmonic frequency components fm, 2fm, 3fm, ... Components fm, 2fm, 3
When fm ... Is removed, the frequency information of the reflected wave signal is also removed and data is lost, so the frequency information of the reflected wave signal and the harmonic frequency components fm, 2fm, 3f.
If the frequency components of m ... match, the vehicle 25 is detected based on the frequency information detected up to that point.
The distance and the relative speed are obtained, that is, the display of the distance and the relative speed obtained at the previous time is held.

Incidentally, the reason why the data is lost is
Since it is only in the case of a combination of a certain distance with the car 25 and the relative speed, the probability of such data loss is low, and the distance with the car 25 and the relative speed change every moment. , Missing in a moment. With such a configuration, in the FM-CW radar device described above, the reflected wave signal from the automobile 25 and the transmission modulation signal from the voltage control oscillator 22 in the transmission system are mixed in the mixer 28, as in the above-described embodiments.
The beat wave signal is obtained by being mixed in the above, and is output to the signal processing unit 30B.

In the signal processing section 30B, the beat wave signal is first subjected to fast Fourier transform by the FFT processing section 311 (step S1) as shown in FIG. The frequency information and the peak value of the reflected wave signal in the signal are extracted (step S2), and the frequency information of the reflected wave signal is further converted by the comparator 315 into the harmonic frequency components fm, 2fm, 3fm of the transmission modulation signal. Is determined (step S3).

As a result, if they do not match, the harmonic removing unit 317 determines the harmonic frequency components fm and 2f.
Even if the frequency components of m, 3fm, ... Are removed from the frequency information of the beat wave signal, the frequency information of the reflected wave signal is not removed. Therefore, based on this frequency information (including the distance frequency fr and the velocity frequency fd) Distance / speed calculator 3
The distance to the automobile 25 and the relative speed are calculated by 13 (from NO route of step S2 to step S4), and displayed to the observer (step S5).

On the other hand, if the frequency information of the reflected wave signal matches the frequency components fm, 2fm, 3fm, ... Of the transmission modulation signal, the harmonic removal unit 317.
This harmonic frequency component fm, 2fm, 3fm
When the frequency component of ... Is removed from the frequency information of the beat wave signal, the frequency information of the reflected wave signal is also removed, so this frequency information is latched by the data latch 316, and as a result, the distance and relative distance The display of speed is held (YES route from step S3 to steps S2 and S6).

As described above, according to the FM-CW radar device (range / velocity detecting radar device) of the present invention, the frequency information of the beat wave signal detected by the signal processing unit 30B through the mixer 23 of the receiving system is obtained. When the distance to the vehicle (target) 25 and the relative speed between the vehicle 25 and the observer are calculated based on the above, the harmonic frequency components (modulation frequency components) fm, 2fm, 3fm of the transmission modulation signal are obtained. Since the calculation is performed after removing the information about, the reception S / N ratio of the radar device can be greatly improved with a simpler configuration as in the device shown in the first embodiment. Therefore, even if the transmission power of the transmission modulation signal is small, there is an advantage that the distance and speed with respect to the automobile 25 can be detected with extremely high accuracy.

(D-1) Description of First Modification of Fourth Embodiment FIG. 17 shows F as a first modification of the fourth embodiment of the present invention.
FIG. 18 is a block diagram showing the configuration of an M-CW radar device (distance / speed detection radar device). The device shown in FIG. 17 has the same voltage as that described in the first embodiment as a transmission system. In addition to the controlled oscillator 22, the amplifier 23, and the transmitting antenna 24, two triangular wave signal generators 21
A and 21B and a selection unit 40 are provided.

Here, one triangular wave signal generator 21A
Is, for example, the repetition frequency as shown in FIG.
fm₁The triangular wave signal with the frequency in the voltage controlled oscillator 22.
It is generated as a signal for number modulation, and the other three angles
The wave signal generator 21A is, for example, as shown in FIG.
Frequency fm as shown₁Repetition frequency fm different from
₂Modulation of triangular wave signal with voltage for voltage controlled oscillator 22
It is generated as a signal for use.

Then, the selecting section 40 switches the outputs of these triangular wave signal generators 21A and 21B in response to a control signal from a signal processing section 30C described later and selectively outputs them to the voltage controlled oscillator 22. It does. That is, in the FM-CW radar device according to the present embodiment, the transmission system selects the plurality of ( _two in this case) triangular wave signals having different repetition frequencies fm ₁ and fm ₂ by the selection unit 40. The transmission antenna 2 transmits the frequency-modulated signal with the triangular wave signal.
4 is configured to be able to transmit.

On the other hand, as the receiving system, in addition to the receiving antenna 26, the low noise amplifier (LNA) 27 and the mixer (MIX) 28 which are the same as those described above in the first embodiment, respectively, the signal processing section 30C and the memory. 35B. Here, the signal processing unit 30C calculates the distance to the automobile (target) 25 and the relative speed based on the frequency information of the beat wave signal detected by the mixer 28 of the reception system, when calculating the transmission system. The calculation is performed after removing the information on the harmonic frequency component (modulation frequency component) of the transmission modulation signal (frequency fm ₁ or fm ₂ ) from the voltage controlled oscillator 22 of the present embodiment. As described above, when the frequency information of the reflected wave signal from the automobile 25 in the beat wave signal and the frequency component of the harmonic frequency component of the transmission modulation signal match, the triangular wave signal generator 21
The control signal for switching the outputs of A and 21B is the selection unit 4
It is configured to be output to 0.

Further, the memory 35B includes the voltage controlled oscillator 2
2, the harmonic frequency components fm ₁ , 2fm ₁ , of the transmission modulation signal having two kinds of frequencies fm ₁ , fm ₂ .
3 fm ₁ , ..., fm ₂ , ₂ fm ₂ , 3 fm ₂ , ...
Are stored respectively, and the harmonic wave removing unit 3
In 17, the harmonic frequency component in the beat wave signal is removed by using any frequency information stored in the memory 35B.

Further, as shown in FIG. 19, the signal processing section 30C has the same F as that described in FIG.
An FT processing unit 311, a peak extraction unit 312, a distance / velocity calculation unit 313, a comparator (COMP) 315, and a harmonic wave removal unit 317 are included in the comparator 315.
From, when the frequency information of the reflected wave signal from the automobile 25 in the beat wave signal and the frequency component of the harmonic of the transmission modulation signal previously stored in the memory 35A match,
A control signal for the selection unit 40 is output so as to switch the outputs of the triangular wave signal generators 21A and 21B.

With such a configuration, also in the FM-CW radar device according to this modification, the beat wave signal detected by the mixer 28 of the receiving system is output to the signal processing unit 30C, and the signal processing unit 30C has the FFT processing unit. The beat wave signal is subjected to fast Fourier transform by 311 and the peak value of the frequency information in the beat wave signal is extracted by the peak extraction unit 312.

The frequency information (peak value) of the beat wave signal obtained by the peak extraction unit 312 is stored in the memory 3 in advance.
The comparator 315 determines whether or not it matches the harmonic frequency component of the transmission modulation signal stored in 5B,
As a result, if they match, the comparators 315 to 3
A control signal for switching the square wave signal generators 21A and 21B is output to the selection unit 40, and the triangle wave signal generators 21A and 21A
The output of 21B is switched.

For example, first, the repetition frequency fm₁Also
The output of the three triangular wave signal generator 21A is selected and the voltage is controlled.
Frequency from oscillator 22 fm₁The transmitted modulated signal is transmitted
Beat wave detected through the mixer 28 while
The frequency information of the received signal in the signal is recorded in the memory 35B.
Stored harmonic frequency component fm₁, 2 fm₁, 3f
m ₁,, ..., the comparator 315 outputs
Is, for example, the repetition frequency fm₂A triangular wave signal with
Input from the triangular wave signal generator 21B to the voltage controlled oscillator 22
The control signal is output to the selection unit 40 so as to be performed.

As a result, as shown in FIG. 18 (a), the voltage-controlled oscillator 22 has a different repetition frequency each time the frequency information of the received signal in the beat wave signal matches the harmonic frequency component of the transmission modulation signal. A voltage waveform having is input, and the frequencies fm ₁ and fm _{2 of} the transmission modulation signal are switched. By the way, the frequency information (beat frequency) of the beat wave signal detected through the mixer 28.
fb is the center frequency of FM modulation (the center frequency of the triangular wave signal) is f ₀ , the frequency deviation width (modulation width) is ΔF, the repetition frequency of the triangular wave signal is fm, the speed of light is c, and Assuming that the distance is R and the relative speed is V, fb = (4 · ΔF · fm / c) · R ± 2f ₀ (V / c) (5) To switch the frequencies fm ₁ and fm ₂ of the transmission modulation signal as follows:
The variable fm in equation (5) will be changed.

[0096] For example, as shown in FIG. 20 (a), the harmonic frequency component in the beat wave signal of the modulated transmission signal having a frequency _{fm 1 fm 1, 2fm 1,} 3fm 1, ···
However, when the frequency information of the received signal matches the frequency information of the received signal, the frequency of the transmission modulated signal is switched to fm ₂ .
As shown in (b), the harmonic frequency components in the beat wave signal are fm ₂ , 2fm ₂ , 3fm ₂ , ...
As a result, the matching between the frequency information of the received signal and the harmonic frequency components fm ₁ , 2fm ₁ , 3fm ₁ , ... Of the modulated transmission signal is shifted by a required amount.

As a result, the harmonic wave removing section 317 causes the harmonic wave frequency components fm ₂ , 2fm ₂ , 3f of the transmission modulation signal.
When removing m ₂ , ..., It is avoided that the frequency information of the received signal is also removed, and the distance / speed calculation unit 3
In 13, the distance to the automobile 25 and the relative speed can be calculated based on only the frequency information of the received signal.

As a result of the judgment by the comparator 315, the frequency information of the reception signal in the beat wave signal and the harmonic frequency components fm ₁ , 2fm ₁ , 3f of the transmission modulation signal are obtained.
While m ₁ , ... Do not match, the harmonic wave removing unit 3
17, the harmonic frequency component fm _{1 of} this transmission modulation signal,
Even if 2fm ₁ , 3fm ₁ , ... Are removed, the frequency information of the received signal is not removed together,
Without switching the frequency of the transmission modulation signal to fm ₂ ,
The distance and speed calculation unit 313 calculates the distance to the automobile 25 and the relative speed.

In this way, the FM-CW in this modification is
According to the radar device, different repetition frequencies fm ₁ ,
Of the two triangular waves having fm ₂ , by transmitting a signal whose frequency is modulated by the triangular wave selected according to the determination result by the comparator 315 of the signal processing unit 30C, the transmission modulation signal of the beat wave signal is transmitted. Since it is possible to shift the matching between the harmonic frequency component and the frequency information of the received signal (reflected signal) by a required amount, the harmonic removal unit 317
It is possible to avoid removing the frequency information of the received signal along with the information about the harmonics of the transmitted modulated signal,
As a result, there is an advantage that the distance and the relative speed with respect to the automobile (target object) 25 with higher accuracy can always be reliably obtained.

By the way, in the above case, the frequencies fm ₁ ,
Although fm ₂ is switched, as can be seen from the equation (5), it becomes meaningless when the relative speed with respect to the automobile 25 is “0”. Therefore, in this case, the harmonic frequency component of the transmission modulation signal in the beat wave signal is changed by changing the variables ΔF (frequency shift amount or modulation width) and f ₀ (center frequency of the transmission modulation signal) in the equation (5). It is possible to shift the matching between the received signal (reflected signal) and frequency information by a required amount.

First, when the frequency shift amount (modulation width) ΔF is made variable, for example, as shown in FIG. 21, as shown in FIG.
A triangular wave signal generator 21C for generating a triangular wave having a modulation width ΔF ₁ as shown in (b), and a triangular wave having a modulation width ΔF ₂ different from the triangular wave signal generator 21C. And a triangular wave signal generator 21D for generating a signal, and the switching unit 40 selectively switches the outputs from the triangular wave signal generators 21C and 21D to the voltage controlled oscillator 22.
The frequency shift amount ΔF for the transmission modulation signal is variable.

As a result, the FM-CW shown in FIG. 21 is obtained.
Also in the radar device, when the harmonic frequency component of the transmission modulation signal in the beat wave signal and the frequency information of the reception signal (reflection signal) match, the triangular wave signal generators 21C and 21D
This match can be shifted by a required amount by selectively switching the output of the above by the selection unit 40 and changing the frequency shift amount ΔF, so that the frequency information of the reception signal is removed together with the harmonic frequency component of the transmission modulation signal. This makes it possible to always reliably obtain a more accurate distance and relative speed to the automobile (target object) 25.

Further, when the center frequency f ₀ of the transmission modulation signal is made variable, for example, as shown in FIG. 22, the triangular wave signal having a required repetition frequency is supplied to the voltage controlled oscillator 2.
A triangular wave signal generator 21E for generating a modulation signal for 2 and a selector 40 'configured as a switch using a capacitor 401 are provided. In addition,
In FIG. 22, the same reference numerals as those shown in FIG. 21 are the same as those shown in FIG. 21, respectively.

With such a configuration, in the FM-CW radar device shown in FIG. 22, when the harmonic frequency component of the transmission modulation signal in the beat wave signal and the frequency information of the reception signal (reflection signal) match, By switching the switch of the selection unit 40 ′ to the capacitor 401 side, for example, as shown in FIG. 18C, the central voltage of the triangular wave input to the voltage controlled oscillator 22 is switched from v ₀ to v _1. The frequency of the transmission modulation signal from the voltage controlled oscillator 22 is also switched from f ₀ to f ₁ .

As a result, in this case as well, the matching between the harmonic frequency component of the transmission modulation signal and the frequency information of the reception signal in the beat wave signal is shifted by a required amount, and the frequency of the reception signal together with the harmonic frequency component of the transmission modulation signal. It is possible to prevent the information from being removed, and thus it is possible to always reliably and accurately obtain the distance and relative speed with respect to the automobile (target object) 25 with higher accuracy. (D-2) Description of Second Modification of Fourth Embodiment FIG. 23 shows F as a second modification of the fourth embodiment of the present invention.
FIG. 24 is a block diagram showing a configuration of an M-CW radar device (distance / velocity detecting radar device). The device shown in FIG. 23 also has a triangular wave signal generator 21, a voltage controlled oscillator 22, and an amplifier as a transmission system. (AMP) and a transmitting antenna 24, and a receiving system including a receiving antenna 26, a low noise amplifier (LNA) 27, and a mixer (MIX) 28, and a signal processing unit 30D and memories 36 and 37. There is.

Here, the signal processing unit (distance / velocity calculation processing unit) 30D has the receiving system mixer 2 also in this modification.
Based on the frequency information of the beat wave signal detected in 8,
When calculating the distance to the vehicle (target) 25 and the relative speed, the harmonic frequency components fm, 2fm of the transmission modulation signal (frequency fm) from the voltage control oscillator 22 of the transmission system are calculated.
The calculation is performed after the information about 3fm, ... Is removed.

For this reason, the signal processing unit 30D is configured as shown in FIG.
As shown in FIG. 4, each F is similar to that shown in FIG.
An FT processing unit 311, a peak extraction unit 312, a distance / speed calculation unit, and a harmonic wave removal unit 317 are included.
The memory 36 is similar to the memory 35A shown in FIG. 14, and stores the harmonic frequency components fm, 2fm, 3fm, ... Of the transmission modulation signal from the transmission system, and the memory 37. Is for storing the distance and relative speed (data) with respect to the past automobile 25 obtained by the signal processing unit 30D.

That is, in this case, the signal processing unit 30D
When the harmonic removal unit 317 removes the frequency information of the received signal together with the harmonic frequency component of the beat wave signal, the distance from the automobile 25 is calculated using the past data stored in the memory 37. And the relative speed are calculated. With such a configuration, also in the FM-CW radar device according to the present modification, the harmonic frequency components fm, 2fm, 3f in the beat wave signal detected by the mixer 28 of the receiving system as described above.
are removed by the harmonic removing unit 317,
The distance to the automobile 25 and the relative speed can be calculated by the distance / speed calculator 313 based on only the frequency information of the received signal. At this time, the harmonic frequency components fm and 2f.
When the frequency information of the received signal is also removed together with m, 3fm, ..., In this modification, the past data stored in the memory 37 is used and the distance to the automobile 25 and the relative speed are used. Calculation by the distance / speed calculation unit 313 is performed.

That is, in the apparatus according to the present modification, the current distance to the automobile 25 and the relative speed at which data is missing are predicted and obtained from past data. For example, it is assumed that a beat wave signal having frequency information as shown in FIG. 25A is obtained through the mixer 28 at a certain point in the past. In this case, since the harmonic frequency components fm, 2fm, 3fm, ... Of the transmission modulated signal from the transmission system do not match the frequency information of the received signal, the harmonic removal unit 317 causes the harmonic frequency component fm, 2fm, 3fm, ...
Even if is removed, the frequency information of the received signal is not lost, and the distance / speed calculator 313 can calculate the distance to the automobile 25 and the relative speed.

The distance / relative velocity data at this point is output as data to be displayed, and the memory 37
Is stored. Then, at the next moment, as shown in FIG. 25B, when the harmonic frequency components fm, 2fm, 3fm, ... Of the transmission modulation signal from the transmission system and the frequency information of the reception signal match, the harmonics When the wave removing unit 317 removes the harmonic frequency components fm, 2fm, 3fm, ..., The frequency information of the received signal is lost.

Therefore, the distance / speed calculator 313 reads the distance / relative speed data with respect to the automobile 25 obtained from the previous calculation from the memory 37, and performs the calculation using this data. Predict and calculate current lost data. For example, 1 by the distance / speed calculation unit 313
By the previous calculation, the distance R ₁ and the relative speed V ₁ with the automobile 25 are obtained, and from this calculation, a minute time (observation interval) Δ
When the frequency information of the received signal is lost after t, first, the distance / speed calculator 313 reads the distance R ₁ and the relative speed V ₁ obtained from the previous calculation from the memory 36.

Here, normally, it is unlikely that the relative speed between the observer and the automobile 25 changes abruptly during the observation interval Δt by the present apparatus, so the distance / speed calculation unit 313 calculates one time before. It is considered that the relative speed at the time of and the relative speed at the present time are the same, and the current vehicle 2
The distance R2 from 5 is obtained. R ₂ = R ₁ + V ₁ · Δt (8) It should be noted that in the memory 37, the automobile 25 obtained as the past data by the distance / speed calculation unit 313 in the previous calculation and the second calculation respectively. It is also possible to store distance / relative speed data with respect to.

That is, for example, at time T, as shown in FIG.
From the frequency information in the beat wave signal as shown in (a), the distance R ₁ and the relative speed V ₁ from the automobile 25 are obtained, respectively, after the observation interval Δt, that is, at time (T + Δt),
If the distance R ₂ and the relative speed V ₂ with respect to the automobile 25 are obtained from the frequency information as shown in FIG. 26 (b), they are stored in the memory 37.

Then, after the observation interval Δt, that is, at the time (T + 2Δt), as shown in FIG. 26C, the frequency information of the received signal and the harmonic frequency components fm, 2fm, 3fm, ... When the and match, and the frequency information for obtaining the distance R ₃ and the relative speed V ₃ with the automobile 25 at this point is lost, the distance / speed calculation unit 313 calculates one time before and The distances R ₁ and R ₂ and the relative velocities V ₁ and V ₂ respectively obtained in the calculation two times before are read, and by using these data, the following calculation is performed to calculate the current time (T + 2Δt). The distance R ₃ and the relative speed V ₃ are obtained.

R ₃ = R ₂ + V ₂ · Δt (9) V ₃ = V ₂ + (V ₂ −V ₁ ) = 2 V ₂ −V ₁ (10) or R ₃ = R _{2 + (R 2 -R 1) =} 2R 2 -R 1 ··· (11) V 3 = 2V 2 -V 1 ··· (12) Thus, according to the FM-CW radar apparatus according to the present modification Even if the frequency information of the reception signal is lost by removing the harmonic frequency component of the transmission modulation signal in the beat wave signal, the signal processing unit 30D uses the past data and compares the distance with the vehicle 25. Since the speed and speed can be calculated, a very simple configuration is always available.
It becomes possible to obtain the distance to the automobile 25 and the relative speed with high accuracy.

As past data, one before and two
By using the distance and the relative speed with respect to the automobile 25 which are respectively obtained in the previous calculation, it is possible to more reliably obtain the distance and the relative speed even if the frequency information of the received signal is lost. You can (D-3) Description of Third Modification of Fourth Embodiment FIG. 27 shows F as a third modification of the fourth embodiment of the present invention.
FIG. 28 is a block diagram showing a configuration of an M-CW radar device (distance / speed detection radar device). The device shown in FIG. 27 also has a triangular wave signal generator 21, a voltage controlled oscillator 22, and an amplifier as a transmission system. 23 and a transmitting antenna 24,
As a receiving system, a receiving antenna 26, a low noise amplifier (LN
A) 27, a mixer (MIX) 28, and a signal processing unit 30E and a memory 38.

Here, the signal processing unit (distance / velocity calculation processing unit) 30E has the receiving system mixer 2 in this modification as well.
Based on the frequency information of the beat wave signal detected in 8,
When calculating the distance to the vehicle (target) 25 and the relative speed, the harmonic frequency components fm, 2fm of the transmission modulation signal (frequency fm) from the voltage control oscillator 22 of the transmission system are calculated.
Although the calculation is performed after removing the information about 3 fm, ... In the present modification, when the distance from the automobile 25 is short and the signal level of the received signal is large to some extent (when it is equal to or higher than a predetermined signal level). ) Is configured to prohibit the information removal processing.

For this reason, the signal processing unit 30E is shown in FIG.
As shown in FIG. 8, each F is the same as that shown in FIG.
An FT processing unit 311, a peak extraction unit 312, a distance / speed calculation unit, a comparator (COMP) 315, and a harmonic wave removal unit 317 are included. The memory 38 stores the above-described predetermined signal level. In the signal processing unit 30E, the predetermined signal level stored in the memory 38 and the beat wave obtained by the peak extraction unit 312 are stored. The comparator 315 compares the peak value (signal level) of the received signal in the signal.

With such a configuration, in the FM-CW radar device according to the present modification, the harmonic frequency component fm of the transmission modulation signal (frequency fm) in the frequency information of the beat wave signal obtained through the mixer 28 of the receiving system. , 2f
When m, 3fm, ... Are removed by the harmonic removing unit 317, the comparator 315 determines whether or not there is a signal having a predetermined signal level or higher among the signals in the beat wave signal.

As a result, for example, as shown in FIG. 29 (a), when there is a signal of a predetermined signal level or higher in the beat wave signal, this signal is a short-distance received signal (data).
, The comparator 315 outputs a control signal for prohibiting the removal processing of the harmonic frequency components fm, 2fm, 3fm, ... To the harmonic removal unit 317, and the harmonic removal unit 317 removes the information. The processing is prohibited, and the distance and relative speed with respect to the automobile 25 is calculated by the distance / speed calculator 313 based on the frequency information of the received signal.

On the other hand, for example, as shown in FIG. 29B, when there is no signal of a predetermined signal level or higher in the beat wave signal, it is considered that there is no short-distance data, and the harmonic wave removing unit 317 is present. Harmonic frequency components fm, 2f
., m, 3fm, ... Are removed, and the distance and relative speed with respect to the automobile 25 is calculated by the distance / speed calculator 313 based on the frequency information (long distance data) of the remaining received signals.

As described above, the FM-CW in this modification
According to the radar device, when the distance to the automobile 25 and the relative speed are calculated by the signal processing unit 30E, the higher harmonic wave removing unit 3 can be used for signals having a predetermined signal level or higher.
17 harmonic frequency components fm, 2fm, 3fm, ...
Since it is possible to prohibit the information removal processing for, the harmonic frequency component fm,
By removing 2 fm, 3 fm, ..., It becomes possible to reliably obtain the distance and relative speed when the distance to the automobile 25 lost is a short distance.

[0123]

As described above in detail, according to the radar apparatus for distance / velocity detection of the present invention, the beat detected by mixing the reflected wave signal from the target and the transmission modulation signal from the transmission system. By passing the wave signal through the high-pass filter, in the distance / velocity calculation processing unit, a modulation frequency component of a predetermined order modulation frequency component or less that occurs near the frequency component of the reflected wave signal and makes it difficult to extract the frequency information of the received signal. Since the distance to the target object and the relative speed between the target object and the observer can be calculated based on the frequency information in the beat wave signal, the configuration is extremely simple and small. There is an advantage that the distance to the target object and the relative speed between the target object and the observer can be detected with high accuracy using electric power (claim 1).

Further, according to the radar apparatus for distance / velocity detection of the present invention, the frequency in the beat wave signal which is lost by blocking the modulation frequency component below the predetermined order modulation frequency component of the transmission modulation signal by the high-pass filter Information (mainly frequency information when the distance to the target is short distance) is complemented by using a radar device for short distance, and the distance to the target and the target and the observer are Since the relative speed of the FM-CW radar device can be obtained, a simple structure in which a radar device for short range is added to the FM-CW radar device having the same structure as that of the device according to claim 1 makes it possible to easily obtain the necessary distance and relative distance. There is an advantage that the speed detection range can be secured (Claim 2).

Furthermore, according to the distance / velocity detecting radar device of the present invention, the FM-AM conversion noise information output in a state where the reflected wave signal from the target object is not received is stored in the storage means. Using the FM-AM conversion noise information stored in the storage means, based on the frequency information obtained by subtracting only the FM-AM conversion noise information in the beat wave signal detected by the receiving system, the distance to the target and the target. And the relative speed between the observer and the observer can be calculated, so that the reception S / N ratio of the device can be significantly improved. As a result, the above distance / The speed and the speed can be detected, and the distance and speed can be easily detected even when the receiving condition of the device is not good (claim 3).

Specifically, in the state where the transmission / reception signal blocking means blocks the exchange of the transmission / reception signal with the outside, the FM
Since the AM-AM conversion noise information is stored in the storage means, the distance / relative velocity to the target object in consideration of the FM-AM conversion noise information can be reliably obtained (claim 4). In this case, if the transmission / reception signal blocking means is composed of switches provided in the transmission system and the reception system, respectively, at least one of these switches provided in the reception system is in the OFF state and the FM-AM conversion noise is stored in the storage means. Since the information can be stored, the distance / relative velocity can be calculated very easily in consideration of the FM-AM conversion noise information (claim 5).

Further, even if the transmission / reception signal blocking means is composed of attenuators provided in the transmission system and the reception system,
Since FM-AM conversion noise information can be stored in the storage means in a signal attenuation state by at least the attenuator provided in the reception system among these attenuators,
The distance / relative velocity can be obtained in consideration of the FM-AM conversion noise information (claim 6).

Further, if the transmission / reception signal blocking means is constituted by a changeover switch capable of switching between the antenna side and the terminator side in the transmission system and the reception system, at least the reception system among these changeover switches is provided. In the state of switching to the terminator side by the changeover switch, the FM-A is stored in the storage means.
Since M conversion noise information can be stored, in this case as well, it becomes possible to obtain the above-mentioned distance / relative velocity in consideration of FM-AM conversion noise information, and the changeover switch is switched to the terminator side. Since the state in which the reflected wave signal from the target object is not received is ensured, it is possible to reliably suppress the influence of signal reflection in the apparatus and obtain a stable operation (claim 7).

Further, according to the distance / speed detection radar device of the present invention, in the distance / speed calculation processing section, based on the frequency information of the beat wave signal detected by the receiving system, the distance to the target and the target are detected. When calculating the relative velocity between the object and the observer, the calculation can be performed after removing the information about the modulation frequency component of the transmission modulation signal, so only the frequency information of the reflected wave signal from the target object Based on, it is possible to obtain the distance to the target object and the relative speed, and thereby, it is possible to reliably detect the above-mentioned distance and speed with high accuracy, and even when the reception state of the device is not good, The distance and speed can be easily detected (claim 8).

At this time, if a signal frequency-modulated by a predetermined modulation signal selected from a plurality of modulation signals having different repetition frequencies is transmitted, the modulation frequency component of the transmission modulation signal and the reception signal (reflection signal) are transmitted. ), The coincidence with the frequency information can be shifted by a predetermined amount, so that it is possible to avoid removing the frequency information of the reception signal together with the information about the modulation frequency component of the transmission modulation signal. The distance to the target and the relative velocity with high accuracy can be obtained, and the necessary observation range can be easily secured (claim 9).

Similarly, when a signal in which the frequency shift amount of the transmission modulation signal is made variable is transmitted, or when a signal in which the transmission center frequency of the transmission modulation signal is made variable is transmitted, the transmission modulation signal is similarly changed. Since the coincidence between the modulation frequency component of and the frequency information of the received signal can be shifted by a predetermined amount, it is possible to avoid that the frequency information of the received signal is removed together with the information about the modulation frequency component of the transmitted modulated signal. In this case as well, it is possible to always obtain a highly accurate distance to the target object and the relative speed, and it is possible to easily secure a necessary observation range (claims 10 and 11).

Further, by removing the information about the modulation frequency component of the transmission modulation signal as described above, even if the frequency information of the reception signal is removed, the distance / velocity calculation processing section can change the past data. The distance to the target object and the relative speed between the target object and the observer can be calculated by using the calculation, so that the distance and the relative speed with respect to the target object can be always and accurately ensured. Can be obtained (Claim 12).

In this case, as the past data, the distance and the relative speed can be easily obtained by using the information of the distance and the relative speed obtained by the previous calculation. 13) Further, by using the information on the distance and the relative speed obtained in the calculation one time before and the calculation two times before, respectively, it is possible to obtain the above-mentioned distance and relative speed with higher accuracy. Item 14).

Further, if the above-described distance / velocity calculation processing unit is configured to prohibit the information removal processing for signals above a predetermined signal level, the reflected wave signal in the beat wave signal will be below the predetermined signal level. Since the information about the modulation frequency component of the transmission modulation signal is removed only when it is, it is possible to reliably suppress the loss of the frequency information of the reflected wave signal from the target object, and always to obtain the high-accuracy The distance and the relative speed can be obtained (claim 15).

[Brief description of drawings]

FIG. 1 is a principle block diagram of the first invention.

FIG. 2 is a principle block diagram of the second invention.

FIG. 3 is a principle block diagram of the third invention.

FIG. 4 is a principle block diagram of the fourth invention.

FIG. 5 is a block diagram showing a configuration of an FM-CW radar device (distance / speed detection radar device) according to the first embodiment of the present invention.

FIG. 6 is a block diagram showing a configuration of a signal processing unit in the FM-CW radar device of the first embodiment.

7 (a) and 7 (b) are FM of the first embodiment, respectively.
FIG. 6 is a diagram for explaining the operation of the CW radar device.

FIG. 8 is a block diagram showing the configuration of a distance / speed detection radar device as a second embodiment of the present invention.

FIG. 9 is a block diagram showing a configuration of an FM-CW radar device (distance / speed detection radar device) as a third embodiment of the present invention.

FIG. 10 is a block diagram showing a configuration of a signal processing unit in the FM-CW radar device of the third embodiment.

11 (a) and (b) are F of the third embodiment, respectively.
It is a figure for demonstrating operation | movement of an M-CW radar apparatus.

FIG. 12 is an FM-C as a first modification of the third embodiment.
It is a block diagram which shows the structure of a W radar apparatus.

FIG. 13 is an FM-C as a second modification of the third embodiment.
It is a block diagram which shows the structure of a W radar apparatus.

FIG. 14 is a block diagram showing a configuration of an FM-CW radar device (distance / speed detection radar device) as a fourth embodiment of the present invention.

FIG. 15 is a block diagram showing a configuration of a signal processing unit in the FM-CW radar device of the fourth embodiment.

FIG. 16 is a flowchart for explaining the operation of the FM-CW radar device of the fourth embodiment.

FIG. 17 is an FM-C as a first modification of the fourth embodiment.
It is a block diagram which shows the structure of a W radar apparatus.

18 (a) to (c) are F of the fourth embodiment, respectively.
It is a figure for demonstrating operation | movement of an M-CW radar apparatus.

FIG. 19 is an FM-C as a first modification of the fourth embodiment.
It is a block diagram which shows the structure of the signal processing part in a W radar apparatus.

20A and 20B are diagrams for explaining the operation of an FM-CW radar device as a first modified example of the fourth embodiment.

FIG. 21 is an FM-C as a first modified example of the fourth embodiment.
It is a block diagram which shows the other structure of a W radar apparatus.

FIG. 22 is an FM-C as a first modified example of the fourth embodiment.
It is a block diagram which shows the other structure of a W radar apparatus.

FIG. 23 is an FM-C as a second modification of the fourth embodiment.
It is a block diagram which shows the structure of a W radar apparatus.

FIG. 24 is an FM-C as a second modification of the fourth embodiment.
It is a block diagram which shows the structure of the signal processing part in a W radar apparatus.

FIGS. 25A and 25B are diagrams for explaining the operation of the FM-CW radar device as the second modification of the fourth embodiment.

26A to 26C are diagrams for explaining another operation of the FM-CW radar device as the second modified example of the fourth embodiment.

FIG. 27 is an FM-C as a third modified example of the fourth embodiment.
It is a block diagram which shows the structure of a W radar apparatus.

FIG. 28 is an FM-C as a third modified example of the fourth embodiment.
It is a block diagram which shows the structure of the signal processing part in a W radar apparatus.

FIG. 29 is an FM-C as a third modified example of the fourth embodiment.
It is a figure for demonstrating operation | movement of a W radar apparatus.

FIG. 30 is a block diagram showing a configuration of a conventional FM-CW radar device.

31A and 31B are conventional FM-CWs, respectively.
It is a figure which shows an example of the triangular wave signal used for a radar apparatus.

FIG. 32 is a block diagram showing a configuration of a signal processing unit in a conventional FM-CW radar device.

33 (a) and 33 (b) are diagrams for explaining the principle of the FM-CW radar device.

FIG. 34 is a diagram for explaining the operation of the conventional FM-CW radar device.

FIG. 35 is a block diagram showing another configuration of a conventional FM-CW radar device.

36 (a) and (b) are conventional FM-CWs.
It is a figure for demonstrating operation | movement of a radar apparatus.

[Explanation of symbols]

1 Voltage Controlled Oscillator 2, 24 Transmitting Antenna 3 Target Object 4, 26 Receiving Antenna 5 Mixer 6 High Pass Filter 7, 7A, 7B Distance / Speed Calculation Processor 8 Radar Device for Short Distance 9 Transmitting / Receiving Antenna 10 Switching Unit 11 Storage Means 21 , 21A to 21D 3 square wave signal generator 22 voltage controlled oscillator 23 amplifier (AMP) 25 automobile (target) 27 low noise amplifier (LNA) 28 mixer (MIX) 29 high pass filter (HPF) 30, 30A to 30E signal processing Unit (distance / speed calculation processing unit) 31 Infrared radar device (Radar device for short range) 32 Antenna for infrared radar device 33 Switching unit 35 Memory (storage means) 35A, 35B, 36 to 38 Memory 36A, 36B switch ( Transmission / reception signal blocking means) 37A, 37B Variable attenuator (ATT) 3 8A, 38B Changeover switch 39A, 39B Terminator 40, 40 'Selection unit 311 FFT processing unit 312 Peak extraction unit 313 Distance / speed calculation unit 314 Noise subtraction unit 315 Comparator (COMP) 316 Data latch unit 317 Harmonic wave removal unit 401 Capacitor

Claims (15)

[Claims] 1. A transmission system for transmitting a signal frequency-modulated by a modulation signal having a predetermined repetition frequency, and a reflected wave signal in which a transmission modulation signal from the transmission system is reflected by a target object and the reflection signal is received. A reception system that mixes a wave signal and the transmission modulation signal from the transmission system to detect a beat wave signal of the reflection wave signal and the transmission modulation signal, and the beat wave signal detected by the reception system, A high-pass filter for blocking a signal having a modulation frequency component equal to or lower than a predetermined-order modulation frequency component of the transmission modulation signal, and a distance to the target object based on frequency information in the beat wave signal filtered by the high-pass filter. A distance / speed calculation processing unit for calculating the relative speed between the target object and the observer by calculation,
A radar device for distance / speed detection. 2. A transmission system for transmitting a signal frequency-modulated by a modulation signal having a predetermined repetition frequency, a transmission wave signal from the transmission system for receiving a reflection wave signal reflected by a target, and the reflection wave. A reception system that mixes a signal and a transmission modulation signal from the transmission system to detect a beat wave signal of the reflected wave signal and the transmission modulation signal; and the transmission of the beat wave signal detected by the reception system. A high-pass filter that blocks a signal having a modulation frequency component equal to or lower than a predetermined order modulation frequency component of a modulation signal, and a distance to the target object and the target object based on frequency information in the beat wave signal filtered by the high-pass filter And an FM-CW radar device configured to include a distance / velocity calculation processing unit that calculates the relative velocity between the FM-CW radar and the observer. Wherein the radar device for different types of short-range is provided as location, distance and speed detecting radar device. 3. A transmission system for transmitting a signal frequency-modulated by a modulation signal having a predetermined repetition frequency, a transmission modulation signal from the transmission system for receiving a reflected wave signal reflected by a target object, and the reflection signal. A reception system for detecting a beat wave signal of the reflected wave signal and the transmission modulation signal by mixing the wave signal and the transmission modulation signal from the transmission system, and the frequency of the beat wave signal detected by the reception system A distance / velocity calculation processing unit for calculating the distance to the target object and the relative speed between the target object and the observer based on the information, and receiving the reflected wave signal from the target object. The target object based on the frequency information of the beat wave signal detected by the receiving system, the distance / velocity calculation processing section including storage means for storing FM-AM conversion noise information output in a non-operating state. Distance to the target And the relative velocity between the observer and the observer are calculated by subtracting the FM-AM conversion noise information stored in the storage means, and then performing the calculation. , Radar device for distance / speed detection. 4. The transmission system and the reception system are provided with transmission / reception signal cutoff means capable of cutting off transmission / reception signal exchange with the outside, and in a state in which the transmission / reception signal transmission / reception with the outside is cut off by the transmission / reception signal cutoff means. , The FM- in the storage means
5. The AM conversion noise information is stored, and in the state of transmitting / receiving a transmission / reception signal to / from the outside, the calculation for obtaining the distance / relative velocity in consideration of the FM-AM conversion noise information is performed. The described radar device for distance / speed detection. 5. The transmission / reception signal cutoff means is composed of switches provided in the transmission system and the reception system, respectively, and the storage means is provided when at least one of the switches provided in the reception system is in an off state. 5. The FM-AM conversion noise information is stored in the memory, and the distance / relative velocity is calculated in consideration of the FM-AM conversion noise information when the switches are on. The described radar device for distance / speed detection. 6. The transmission / reception signal blocking means is composed of an attenuator provided in each of the transmission system and the reception system, and in a signal attenuation state by an attenuator provided in at least the reception system among these attenuators. Storing the FM-AM conversion noise information in the storage means, and performing the calculation for obtaining the distance / relative velocity in consideration of the FM-AM conversion noise information in the signal non-attenuation state of these attenuators. The distance / speed detecting radar device according to claim 4. 7. The transmission / reception signal blocking means is composed of a changeover switch capable of switching between the antenna side and the terminator side in the transmission system and the reception system, respectively, and at least the reception system among the changeover switches. In the state of switching to the terminator side by the provided changeover switch, the FM is stored in the storage means.
-AM conversion noise information is stored, and in the state of switching to the antenna side by these changeover switches, the FM-
The distance / relative speed according to claim 4, wherein the distance / relative velocity is calculated in consideration of AM conversion noise information.
Radar device for speed detection. 8. A transmission system for transmitting a signal frequency-modulated by a modulation signal having a predetermined repetition frequency, a transmission wave signal from the transmission system for receiving a reflected wave signal reflected by a target, and the reflection signal. A reception system for detecting a beat wave signal of the reflected wave signal and the transmission modulation signal by mixing the wave signal and the transmission modulation signal from the transmission system, and the frequency of the beat wave signal detected by the reception system A distance / speed calculation processing unit for calculating a distance to the target object and a relative speed between the target object and an observer on the basis of information, and the distance / speed calculation processing unit is provided in the reception system. When the distance to the target object and the relative velocity between the target object and the observer are calculated by the calculation based on the frequency information of the beat wave signal detected in Operation is performed after removing the information of A radar device for distance / velocity detection, which is configured as described above. 9. The transmission system is configured to be capable of transmitting a signal frequency-modulated by a predetermined modulation signal selected from a plurality of modulation signals having different repetition frequencies. The radar device for distance / velocity detection according to claim 8. 10. The radar device for distance / velocity detection according to claim 8, wherein the transmission system is configured so that the frequency shift amount of the transmission modulation signal can be varied. 11. The radar device for distance / velocity detection according to claim 8, wherein the transmission system is configured so that the transmission center frequency of the transmission modulation signal can be made variable. 12. The distance / velocity calculation processing unit, based on frequency information of the beat wave signal detected by the reception system,
9. The calculation is performed by using past data when calculating the distance to the target and the relative velocity between the target and the observer by calculation. The described radar device for distance / speed detection. 13. The radar device for distance / speed detection according to claim 12, wherein the information of the distance and the relative speed obtained in the previous calculation is used as the past data. 14. The distance according to claim 12, wherein the information of the distance and the relative velocity obtained by the calculation one time before and the calculation two times before are used as the past data. Radar device for speed detection. 15. The distance / velocity calculation processing unit, based on frequency information of the beat wave signal detected by the reception system,
9. The information removal processing is prohibited for signals having a predetermined signal level or higher when calculating the distance to the target and the relative speed between the target and the observer by calculation. Radar device for distance and speed detection.