CN117233512B - Broadband noise signal immunity testing system and method based on reverberation room - Google Patents
Broadband noise signal immunity testing system and method based on reverberation room Download PDFInfo
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Abstract
The invention discloses a broadband noise signal immunity testing system and method based on a reverberation room, and relates to the technical field of electromagnetic variable testing. The invention adopts a broadband noise signal immunity testing system comprising a signal generating device, a transmitting antenna, a reverberation room, a tuner and a working space; in the process of testing the noise immunity of the broadband noise signal, the output power of the continuous wave CW signal generated by the signal generating device is regulated until the indoor field intensity of the reverberation reaches the target test field intensity, the output power of the broadband noise signal is determined based on the output power of the continuous wave CW signal generated by the signal generating device and the crest factor of the broadband noise signal, and the noise immunity performance of the broadband signal of the vehicle is tested rapidly and efficiently on the basis of the signal power of the broadband noise signal without depending on a general database.
Description
Technical Field
The invention relates to the technical field of electromagnetic variable testing, in particular to a broadband noise signal immunity testing system and method based on a reverberation room.
Background
With the improvement of the integration level of the vehicle electronic and electric system, the electromagnetic sensitivity level of the vehicle is continuously improved, and the vehicle is more easily influenced by electromagnetic signals in the environment. In an actual electromagnetic environment, not only a narrow-band interference signal exists, but also a broadband interference signal exists, and at present, a plurality of cases show that an electromagnetic compatibility fault is caused by the interference of the broadband signal in the actual environment on a vehicle, so that the driving safety and the user experience are seriously affected.
At present, two main technical schemes are adopted for checking the electromagnetic radiation immunity of a vehicle, namely a narrow-band immunity test based on a half-anechoic chamber and a collection playback immunity test, and a narrow-band immunity test based on a reverberation chamber. The influence of the broadband signal is not checked in the narrow-band immunity test related to the two technical schemes, and on the other hand, the acquisition playback immunity test related to the former needs to be realized based on a large-scale database, so that the product performance evaluation of enterprises not building the database is not facilitated.
Disclosure of Invention
In order to solve the problems in the prior art, the invention provides a broadband noise signal immunity testing system and method based on a reverberation room.
In order to achieve the above object, the present invention provides the following solutions:
a reverberation room based broadband noise signal immunity test system comprising: a signal generating device, a transmitting antenna, a reverberation room, a tuner, and a working space;
the signal generating device is connected with the transmitting antenna; the signal generating device is used for generating a continuous wave CW signal and a broadband noise signal; the tuner, the transmitting antenna and the working space are all arranged in the reverberation chamber; a test vehicle is located in the workspace;
the tuner is used for forming spatially uniform field intensity in the reverberation chamber through rotation; and in the reverberation room, completing the broadband noise signal immunity test of the test vehicle.
Optionally, the broadband noise signal immunity test system further includes: a directional coupler, a power meter and a power amplifier;
the signal generating device, the directional coupler, the power meter and the power amplifier are all arranged in an operation room; the signal generating device is connected with the power amplifier; the directional coupler is respectively connected with the power amplifier, the power meter and the transmitting antenna.
Optionally, the broadband noise signal immunity test system further includes: an electric field probe; the electric field probe is arranged at the vertex of the working space; the electric field probe is used for detecting the maximum field intensity in the X direction, the Y direction and the Z direction in the reverberation chamber.
A broadband noise signal immunity test method based on a reverberation room is applied to the broadband noise signal immunity test system based on the reverberation room; the method comprises the following steps:
obtaining a target test field intensity;
regulating the output power of the continuous wave CW signal generated by the signal generating device until the field intensity in the reverberation room reaches the target test field intensity, and recording the output power of the continuous wave CW signal generated at the moment;
acquiring a crest factor of a broadband noise signal, and determining the output power of the broadband noise signal based on the recorded output power of the continuous wave CW signal and the crest factor of the broadband noise signal;
and setting the signal power of the broadband noise signal output by the signal generating device as the output power of the broadband noise signal, and testing the broadband noise signal immunity of the test vehicle.
Optionally, before acquiring the target test field strength, the method further comprises:
detecting the maximum field intensity in the X direction, the Y direction and the Z direction in the reverberation chamber by adopting an electric field probe;
taking the average value of the maximum field intensity in the X direction, the Y direction and the Z direction as the field intensity in the reverberation chamber.
Optionally, the determination formula of the output power of the wideband noise signal is:
；
in the method, in the process of the invention,output power for wideband noise signal, +.>For the output power of the continuous wave CW signal generated by the signal generating device, < >>Is the crest factor of the wideband noise signal.
Optionally, the crest factor of the broadband noise signal is obtained using an oscilloscope test.
Optionally, the power density of the broadband noise signal output by the signal generating device is:
；
in the method, in the process of the invention,for the power density of the broadband noise signal, +.>For the target test field strength +.>A bandwidth selected for the wideband noise signal.
According to the specific embodiment provided by the invention, the invention discloses the following technical effects:
the invention adopts a broadband noise signal immunity testing system comprising a signal generating device, a transmitting antenna, a reverberation room, a tuner and a working space, and in the process of testing the broadband noise signal immunity, the output power of a continuous wave CW signal generated by the signal generating device is regulated until the indoor field strength of the reverberation reaches the target test field strength, the output power of the broadband noise signal is determined based on the output power of the continuous wave CW signal generated by the signal generating device and the crest factor of the broadband noise signal, and the broadband noise signal immunity performance of a vehicle is tested rapidly and efficiently on the basis of the signal power of the broadband noise signal without depending on a general database.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings that are needed in the embodiments will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.
FIG. 1 is a block diagram of a wideband noise signal immunity test system based on a reverberation room according to the present invention;
FIG. 2 is a schematic diagram of signal field intensity calibration in a wideband noise signal immunity test system based on a reverberation room provided by the invention;
FIG. 3 is a diagram of a wideband noise signal generation scheme provided by the present invention;
fig. 4 is a schematic diagram of a spectrum of a band-limited gaussian white noise signal according to the present invention;
fig. 5 is a schematic diagram of a band-limited gaussian white noise signal spectrum provided by the present invention.
Symbol description:
the device comprises a 1-reverberation room, a 2-operation room, a 3-working space, a 4-tuner, a 5-dynamometer, a 6-test vehicle, a 7-transmitting antenna, an 8-signal generating device, a 9-power amplifier, a 10-directional coupler, an 11-power meter and a 12-electric field probe.
Detailed Description
The following description of the embodiments of the present invention will be made clearly and completely with reference to the accompanying drawings, in which it is apparent that the embodiments described are only some embodiments of the present invention, but not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.
The invention aims to provide a broadband noise signal immunity testing system and method based on a reverberation room, which can quickly and efficiently test the broadband noise signal immunity performance of a vehicle under the condition of not depending on a general database.
In order that the above-recited objects, features and advantages of the present invention will become more readily apparent, a more particular description of the invention will be rendered by reference to the appended drawings and appended detailed description.
As shown in fig. 1, the wideband noise signal immunity testing system based on a reverberation room provided by the invention comprises: a signal generating means 8, a transmitting antenna 7, a reverberation room 1, a tuner 4 and a working space 3.
The signal generating means 8 are connected to the transmitting antenna 7. The signal generating means 8 are arranged to generate a continuous wave CW signal and a broadband noise signal. The tuner 4, the transmitting antenna 7 and the working space 3 are all arranged in the reverberation room 1. A test vehicle 6 is located in the working space 3.
The tuner 4 is arranged to create a spatially uniform field strength in the reverberation chamber 1 by rotation.
In the reverberation chamber 1, the broadband noise signal immunity test of the test vehicle 6 is completed.
Furthermore, in order to improve the accuracy of the test, the broadband noise signal immunity test system provided by the invention can be further provided with a directional coupler 10, a power meter 11 and a power amplifier 9.
Wherein the signal generating means 8, the directional coupler 10, the power meter 11 and the power amplifier 9 are arranged in the operating room 2. The signal generating means 8 are connected to a power amplifier 9. The directional coupler 10 is connected to the power amplifier 9, the power meter 11 and the transmitting antenna 7, respectively.
Further, in order to accurately obtain the field intensity in the reverberation room 1, the broadband noise signal immunity test system provided by the invention can be further provided with an electric field probe 12. In practice, as shown in fig. 2, an electric field probe 12 may be arranged at the apex of the working space 3 in order to detect the maximum field strengths in the X-direction, Y-direction and Z-direction in the reverberation chamber 1.
Furthermore, the invention also provides a method for testing the immunity of the broadband noise signal based on the reverberation room, which is applied to the system for testing the immunity of the broadband noise signal based on the reverberation room. As shown in fig. 3, the method includes:
step 100: and obtaining the target test field intensity.
Step 101: and adjusting the output power of the continuous wave CW signal generated by the signal generating device until the field intensity in the reverberation chamber reaches the target test field intensity, and recording the output power of the continuous wave CW signal generated at the moment.
In the practical application process, after the electric field probe is adopted to detect the maximum field intensity in the X direction, the Y direction and the Z direction in the reverberation chamber, the average value of the maximum field intensity in the X direction, the Y direction and the Z direction is taken as the field intensity in the reverberation chamber.
Step 102: and acquiring a crest factor of the broadband noise signal, and determining the output power of the broadband noise signal based on the recorded output power of the continuous wave CW signal and the crest factor of the broadband noise signal. The determination formula of the output power of the broadband noise signal is as follows:
。
in the method, in the process of the invention,output power of broadband noise signal in +.>。/>The output power of the continuous wave CW signal generated by the signal generating device is in units of +.>。/>Crest factor of broadband noise signal in +.>。
In the practical application process, the crest factor of the broadband noise signal is obtained by utilizing an oscilloscope test.
Step 103: the signal power of the broadband noise signal output by the signal generating device is set as the output power of the broadband noise signal, and the immunity of the broadband noise signal of the test vehicle is tested.
In an actual application process, a processor may be provided in the system for testing the immunity of the broadband noise signal based on the reverberation room, so as to implement the method for testing the immunity of the broadband noise signal based on the reverberation room. In addition, the broadband noise signal immunity testing method based on the reverberation room can be realized by means of signal adjustment, power setting and the like by workers.
The following describes the implementation process of the scheme provided by the invention based on the practical application.
Various types of broadband signals exist in an electromagnetic environment, and parameters such as the number of carriers, the modulation mode and the like of different broadband signals are different. In order to facilitate calibration and tracing, and combining the characteristics of the broadband signal, in the testing process of adopting the broadband noise signal immunity testing system provided by the above, the broadband white Gaussian noise signal with the bandwidth limit can be used as the broadband noise signal for testing. The test signal was generated in the manner shown in fig. 4, and its power density was:
。
in the method, in the process of the invention,is the power density of the broadband noise signal in +.>。/>For the target test field strength, the unit is +.>。/>The bandwidth selected for the wideband noise signal is in +.>。
Based on this, in the process of performing the wideband noise signal immunity test, the wideband noise signal immunity test system based on the reverberation room as shown in fig. 1 provided above may be built first. In the practical application process, the wideband noise signal immunity test system based on the reverberation room, which is actually built, may be a test environment formed by the signal generating device 8, the power amplifier 9, the transmitting antenna 7, the reverberation room 1, the tuner 4, the working space 3, and the like.
The continuous wave CW signal generated by the signal generating device 8 in fig. 2 is set so that the continuous wave CW signal output by the signal generating device 8 has the same frequency as the center frequency, based on the center frequency of the broadband noise signal shown in fig. 4. The tuner 4 is set to work, the maximum field intensity in the three directions of X, Y, Z is measured by the electric field probes 12 at the eight vertexes of the working space 3, and the average value of the maximum field intensity in the three directions of X, Y, Z is taken as the field intensity in the reverberation chamber 1. Regulating the output power of the signal generating device 8 until the field strength in the reverberation room 1 reaches the target test field strength, recording the output power of the continuous wave CW signal of the signal generating device 8 at this time。
Setting the center frequency and bandwidth of the broadband noise signal, connecting the radio frequency output end of the signal generating device shown in fig. 4 with an oscilloscope, and testing the crest factor of the broadband noise signal by using the oscilloscopeAnd further obtaining the output power of the broadband noise signal.
The test arrangement is performed according to the specific structure of the system in fig. 1, and the signal power of the broadband noise signal output by the signal generating device 8 is set to the output power of the broadband noise signal obtained above, so as to test and verify the broadband noise signal immunity of the test vehicle 6, and in this test process, the broadband noise signal immunity of the test vehicle 6 is completed by the dynamometer 5.
In the test process, the wideband noise signal may be a band-limited gaussian white noise signal, as shown in fig. 5, where the center frequency is 1GHz and the bandwidth is 20MHz.
Based on the description, the broadband noise signal immunity testing system and method based on the reverberation room provided by the invention can construct an electromagnetic environment which is quite spatially uniform and directional uniform as an actual road environment by virtue of the advantages of the reverberation room testing environment, and can simply and efficiently test the electromagnetic immunity performance of a vehicle under the effect of the broadband noise signal by virtue of the characteristics of uniform spectrum distribution and uniform power density of the broadband noise signal on the one hand, and is convenient for signal calibration and tracing, thereby being beneficial to providing support for developing and verifying enterprises, reducing the electromagnetic safety risk of the vehicle in the actual road environment and having important significance for promoting the electromagnetic compatibility quality improvement of vehicle products.
In the present specification, each embodiment is described in a progressive manner, and each embodiment is mainly described in a different point from other embodiments, and identical and similar parts between the embodiments are all enough to refer to each other.
The principles and embodiments of the present invention have been described herein with reference to specific examples, the description of which is intended only to assist in understanding the methods of the present invention and the core ideas thereof; also, it is within the scope of the present invention to be modified by those of ordinary skill in the art in light of the present teachings. In view of the foregoing, this description should not be construed as limiting the invention.
Claims (6)
1. A method for testing immunity to broadband noise signals based on a reverberant room, the method comprising:
obtaining a target test field intensity;
regulating the output power of the continuous wave CW signal generated by the signal generating device until the field intensity in the reverberation room reaches the target test field intensity, and recording the output power of the continuous wave CW signal generated at the moment;
acquiring a crest factor of a broadband noise signal, and determining the output power of the broadband noise signal based on the recorded output power of the continuous wave CW signal and the crest factor of the broadband noise signal; the determination formula of the output power of the broadband noise signal is as follows:
the method comprises the steps of carrying out a first treatment on the surface of the In (1) the->Output power for wideband noise signal, +.>For the output power of the continuous wave CW signal generated by the signal generating means, < >>Crest factor for wideband noise signal;
setting the signal power of the broadband noise signal output by the signal generating device as the output power of the broadband noise signal, and testing the broadband noise signal immunity of the test vehicle; wherein, the power density of the broadband noise signal output by the signal generating device is:
；
in the method, in the process of the invention,for the power density of the broadband noise signal, +.>For the target test field strength +.>A bandwidth selected for the wideband noise signal.
2. The reverberation chamber based broadband noise signal immunity testing method according to claim 1, further comprising, before acquiring the target test field strength:
detecting the maximum field intensity in the X direction, the Y direction and the Z direction in the reverberation chamber by adopting an electric field probe;
taking the average value of the maximum field intensity in the X direction, the Y direction and the Z direction as the field intensity in the reverberation chamber.
3. The method for testing the immunity of the broadband noise signal based on the reverberation room according to claim 1, wherein the crest factor of the broadband noise signal is obtained by using an oscilloscope test.
4. A system for testing the immunity of a broadband noise signal based on a reverberation room, which is characterized by being applied to the method for testing the immunity of the broadband noise signal based on the reverberation room according to any one of claims 1 to 3; the system comprises: a signal generating device, a transmitting antenna, a reverberation room, a tuner, and a working space;
the signal generating device is connected with the transmitting antenna; the signal generating device is used for generating a continuous wave CW signal and a broadband noise signal; the tuner, the transmitting antenna and the working space are all arranged in the reverberation chamber; a test vehicle is located in the workspace;
the tuner is used for forming spatially uniform field intensity in the reverberation chamber through rotation; in the reverberation room, completing a broadband noise signal immunity test of the test vehicle; in the process of testing the noise immunity of the broadband noise signal, the output power of the continuous wave CW signal generated by the signal generating device is regulated until the indoor field intensity of the reverberation reaches the target test field intensity, the output power of the broadband noise signal is determined based on the output power of the continuous wave CW signal generated by the signal generating device and the crest factor of the broadband noise signal, and the noise immunity performance of the broadband signal of the vehicle is tested based on the determined output power of the broadband noise signal.
5. The reverberation chamber based broadband noise signal immunity testing system according to claim 4, further comprising: a directional coupler, a power meter and a power amplifier;
the signal generating device, the directional coupler, the power meter and the power amplifier are all arranged in an operation room; the signal generating device is connected with the power amplifier; the directional coupler is respectively connected with the power amplifier, the power meter and the transmitting antenna.
6. The reverberation chamber based broadband noise signal immunity testing system according to claim 4, further comprising: an electric field probe; the electric field probe is arranged at the vertex of the working space; the electric field probe is used for detecting the maximum field intensity in the X direction, the Y direction and the Z direction in the reverberation chamber.
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