KR100944026B1 - System for correcting error of laser reflection signal level fluctuation and method there for - Google Patents

Abstract

The present invention relates to an error correction system and method for changing the laser reflection signal level, the laser output module for emitting a laser signal for measuring the distance to the target object to the target object, and the reflected signal reflected from the target object Reflected signal receiving module for receiving and half-half and converting to digital at the same time, Reflected signal mixing module for converting laser signal and half-time signal into standard reflected signal and deriving amplitude coefficient, and reference reflected signal And an amplitude conversion module that derives a first delay time by superimposing a trigger signal according to an amplitude coefficient, and derives a second delay time by superimposing a trigger signal and a 3K reflection signal obtained by converting a host reflection signal into a square wave and an amplitude coefficient. , Overlap the reference reflection signal and the 3K reflection signal with the trigger signal according to the amplitude coefficient, A phase difference measuring module for measuring a difference with a third delay time and measuring a phase difference between the 3K reflected signal and a trigger point with a fourth delay time to derive a phase difference between the reference reflected signal and the 3K reflected signal, and an average of the phase differences as a corrected phase difference. And a reflection signal correction module for deriving and correcting phases of the reference reflection signal and the 3K reflection signal.

Laser, reflected signal, amplitude, trigger signal, phase difference, correction

Description

Error correction system due to laser reflection signal level fluctuation and its method {SYSTEM FOR CORRECTING ERROR OF LASER REFLECTION SIGNAL LEVEL FLUCTUATION AND METHOD THERE FOR}

The present invention relates to an error correction system due to a laser reflection signal level variation, and more particularly, to a technique for correcting an error of a reflection signal reflected from a target object to provide accurate displacement measurement.

Laser displacement measurement technology is a technology that calculates the distance by emitting the light emitted from the laser diode to the object to be measured by measuring the wavelength of the laser that comes back from the measurement object and reflected back.

Laser displacement measurement technology is widely used for non-contact measurement without direct contact with distant targets for military and industrial use. It is expected that its use in industrial use will be expanded in the future and is being studied in various angles by many researchers. .

Generally, laser displacement measurement technology is divided into long-range measurement technology and short-range measurement technology. For the long-range measurement method, the measurement method is mostly performed by the time-of-fight method. Has a big disadvantage [1].

In addition, short-range measurement has been carried out by triangulation [2], and recently, a study on surveying by applying both time-flight and triangulation techniques simultaneously to apply a laser displacement meter to an industrial purpose. There was also [3].

This laser displacement measurement technology is based on the maximum measurement distance of 1Km, the minimum measurement distance of 10Cm, and the measurement error based on ㅁ 0mm to meet the requirements of ultra high precision, miniaturization, light weight, and high speed measurement required in the automation industry. Are becoming increasingly common [3].

Laser has been applied to high precision distance measurement and azimuth measurement by using it because of high reflectance and light going straight, and it has been used for industrial purposes recently, which is mainly used for military purposes.

However, in spite of the above-described laser characteristics and extensive research, the displacement measurement technique using lasers has some characteristic problems. That is, the intensity of the light that is reflected and returned to the measurement object varies greatly depending on the distance and the surface state of the reflecting object, and the variation in measurement error due to the intensity of the light period is too large.

In this case, the displacement measurement greatly increases the number of measurements and reduces the distance error width through the average value. However, as the measurement time increases in proportion to the number of measurement repetitions, it is not suitable for a system requiring high-speed measurement.

Prior literature information

[1] Donati, Electro-Optical Instrumentation. Upper Saddle River, NJ: Prentice-hall, 2004.

[2] M.C. Amann, T. Bosch, M. Lescure, R. Myllyla, and M. Rioux, "Laser ranging: A critical review of usual techniques for distance measurement," Opt. Eng., Vol. 40, no. Pp. 10-19, 2001.

[3] Young-Chul Bae, Lee-Kon Kim, Jong-Bae Kim, Chun-Seok Kim, Eui-Joo Seo, Jong-Ju A. Amorph, Ku Young-Deok, "A Study on the Development of High Precision Laser Distance Meter", Journal of The Korean Institute of Maritime Information and Communication Sciences, Vol. 10, No. 12, pp. 2296-2302, 2006.

The present invention has been made to solve the above problems, by minimizing the error of the reflected signal reflected from the target object, and by correcting the error of the variation of the reflected signal due to the surface reflectance of the target object and the distance difference between the target object, Ensure accurate displacement measurements.

The error correction system according to the laser reflection signal level variation of the present invention for achieving the above technical problem, the laser output module for emitting a laser signal for measuring the distance to the target object, and the reflection reflected from the target object Reflective signal receiving module that receives and half-halves the signal and converts it to digital, and converts the laser signal and the half-time signal into a standard reflected signal and converts it into a standard reflected signal and derives the amplitude coefficient, and the reference Amplitude conversion that derives the first delay time by superimposing the reflected signal and the trigger signal according to the amplitude coefficient, and derives the second delay time by superimposing the 3K reflected signal and the trigger signal obtained by converting the host reflected signal into a square wave according to the amplitude coefficient. Module, the reference reflection signal and the 3K reflection signal are superimposed with the trigger signal according to the amplitude coefficient and the reference reflection signal and the trigger A phase difference measuring module for measuring a phase difference between the points with a third delay time and a phase difference between the 3K reflected signal and the trigger point with a fourth delay time to derive the phase difference between the reference reflected signal and the 3K reflected signal, and correcting an average of the phase differences. And a reflection signal correction module for correcting phases of the reference reflection signal and the 3K reflection signal by deriving the phase difference.

In addition, the reflection signal mixing module is characterized by converting the laser signal and the half-time signal to a reference reflection signal having a frequency of 2.5KHz to 3.5KHz.

는 트리거 신호 레벨이고,

는 상기 기준 반사신호의 최대레벨이며,

는 각 신호의 주기를 의미하는 것을 특징한다.The first to fourth delay times may be derived through Equation 4 by superimposing a reference reflection signal, a 3K reflection signal, and a trigger signal according to an amplitude coefficient.

Is the trigger signal level,

Is the maximum level of the reference reflection signal,

Denotes a period of each signal.

In addition, the phase difference between the reference reflection signal and the 3K reflection signal is derived through Equation 5, DV denotes a distance value, CV denotes a distance measured value by an amplitude coefficient, and t1 denotes a third delay time. t2 means a fourth delay time.

In addition, the correction phase difference is characterized in that derived through [Equation 6].

On the other hand, the error correction method according to the laser reflection signal level variation according to the present invention, the first process of radiating the laser signal to the target object, and receives the reflected signal reflected from the target object by the laser signal and halved to 1/2 And a second step of digitizing, a third step of adding a laser signal and a reflected signal to convert the reference signal into a reference reflected signal having a frequency of 3 KHz, and deriving an amplitude coefficient, and a trigger signal generated by the reference reflected signal and the trigger comparator. 4th process of deriving the first delay time by superimposing the amplitude delay coefficients and deriving the second delay time by superimposing the 3K reflected signal and the trigger signal obtained by converting the reference reflected signal into a square wave according to the amplitude coefficient; The signal and the 3K reflected signal are superimposed on the trigger signal according to the amplitude coefficient, and the phase difference between the reference reflected signal and the trigger point is measured as the third delay time. A fifth process of deriving the phase difference between the reference reflection signal and the 3K reflection signal by measuring the phase difference between the reflected signal and the trigger point with a fourth delay time, and deriving the average of the derived phase differences as the correction phase difference to obtain the reference reflection signal and the 3K reflection signal. And a sixth process of correcting the phase of the circuit.

In addition, the fourth process includes: superimposing the reference reflection signal and the trigger signal according to an amplitude coefficient, deriving a first delay time between the reference reflection signal and the trigger signal according to Equation 4, and the reference reflection. Converting the signal into a square wave, superimposing the 3K reflected signal and the trigger signal converted into the square wave according to an amplitude coefficient, and deriving a second delay time between the 3K reflected signal and the trigger signal according to [Equation 4]. Steps.

In the fifth process, the reference reflection signal and the 3K reflection signal are overlapped with the trigger signal according to the amplitude coefficient, and the phase difference between the reference reflection signal and the trigger point is measured as the third delay time according to [Equation 4]. And measuring the phase difference between the 3K reflected signal and the trigger point with a fourth delay time according to [Equation 4], and deriving the phase difference between the reference reflected signal and the 3K reflected signal through [Equation 5]. It includes.

According to the present invention as described above, by converting the reflected signal reflected from the target object into a reflected signal having a frequency of 3KHz, and into a square wave, and superimposed them on the trigger signal, the phase difference between the signals according to the delay time derived By correcting, there is an effect of minimizing the error of the reflected signal.

In addition, by correcting an error in the variation of the reflection signal due to the surface reflectance of the target object and the distance difference between the target object, there is an effect of providing accurate displacement measurement.

Specific features and advantages of the present invention will become more apparent from the following detailed description based on the accompanying drawings. Prior to this, the terms or words used in the present specification and claims are defined in the technical spirit of the present invention on the basis of the principle that the inventor can appropriately define the concept of the term in order to explain his invention in the best way. It should be interpreted to mean meanings and concepts. In addition, when it is determined that the detailed description of the known function and its configuration related to the present invention may unnecessarily obscure the subject matter of the present invention, it should be noted that the detailed description is omitted.

1 is a block diagram showing an error correction system due to the laser reflection signal level variation according to the present invention, Figure 2 is a view showing the relationship between the components of the error correction system due to the laser reflection signal level variation of the present invention.

As shown in FIG. 1, the error correction system 100 according to the laser reflection signal level variation according to the present invention includes a laser output module 110, a reflection signal receiving module 120, a reflection signal mixing module 130, and an amplitude. The conversion module 140, the phase difference measuring module 150, and the reflection signal correction module 160 are included.

In detail, referring to FIG. 2, the laser output module 110 generates a laser signal for measuring a distance from the target object 10 through the laser diode 111 to emit the laser signal to the target object, as well as a reflection signal mixing module ( 130).

Here, the emitted laser signal is shown in Equation 1 below.

[Equation 1]

The reflection signal receiving module 120 receives the laser signal reflected from the target object (hereinafter referred to as the 'reflection signal') and half-halves the half through the flip-flop 121 at the same time. 2] is converted to digital, and the digitized reflection signal is applied to the reflection signal mixing module 130.

[Equation 2]

The reflection signal mixing module 130 adds the laser signal radiated to the target object applied from the laser output module 110 and the reflection signal received from the reflection signal receiving module 120 to a frequency of 2.5KHz to 3.5KHz, preferably Is converted into a reflection signal having a frequency of 3KHz (hereinafter referred to as a 'reference reflection signal') and applied to the amplitude conversion module 140 and the phase difference measurement module 150.

Here, the converted reference reflection signal is expressed by Equation 3 below.

[Equation 3]

는 가변,

는 고정 값 인 것으로 상정하여

를 진폭계수로 도출한다.Further, the reference reflection signal converted by Equation 3

Is variable,

Is assumed to be a fixed value

Derived as the amplitude factor.

The converted reference reflection signal is applied to the amplitude conversion module 140 and the amplitude coefficient is applied to the amplitude conversion module 140 and the phase difference measurement module 150.

Referring to FIG. 3, the amplitude conversion module 140 overlaps the reference reflection signal received from the reflection signal mixing module 130 and the trigger signal generated by the trigger comparator according to the amplitude coefficient so as to overlap the first delay time. Deriving t1, superimposing a signal obtained by converting the reference reflected signal into a square wave (hereinafter referred to as a '3K reflected signal') and a trigger signal according to an amplitude coefficient to derive a second delay time t2, and converting the converted 3K reflected signal The signal and the first delay time t1 and the second delay time t2 are applied to the phase difference measuring module 150.

는 트리거 신호 레벨이고,

는 기준 반사신호의 최대레벨이며,

는 각 신호의 주기이다.Here, the first and second delay times are derived through Equation 4 below.

Is the trigger signal level,

Is the maximum level of the reference reflection signal,

Is the period of each signal.

[Equation 4]

Referring to FIG. 4, the phase difference measurement module 150 superimposes the reference reflection signal and the 3K reflection signal with the trigger signal according to the amplitude coefficient, and measures the phase difference between the reference reflection signal and the trigger point with a third delay time t1, and 3K. By measuring the phase difference between the reflected signal and the trigger point with a fourth delay time t2, the phase difference between the reference reflected signal and the 3K reflected signal is derived through Equation 5 below, and the 3K reflected signal and the phase difference are reflected signal correction module ( 160).

In this case, the third delay time t1 and the fourth delay time t2 are derived through Equation 4 above.

[Equation 5]

Here, DV is a distance value, CV is a distance measurement value based on an amplitude coefficient, and the third delay time t1 and the fourth delay time t2 are derived through Equation 4 above.

The reflected signal correction module 160 derives an average of the phase differences as a corrected phase difference to correct phases of the reference reflected signal and the 3K reflected signal.

Here, the correction phase difference is derived through Equation 6 below.

[Equation 6]

Hereinafter, an error correction method according to the laser reflection signal level variation of the present invention will be described with reference to FIGS. 5 to 7.

As shown in FIG. 5, the laser output module 110 emits a laser signal to the target object 10 (first process S10).

In addition, the reflection signal receiving module 120 receives the reflection signal reflected from the target object by the laser signal and halves and digitizes it to 1/2 and applies it to the reflection signal mixing module 130 (second step S20). ).

In addition, the reflection signal mixing module 130 adds the laser signal and the reflection signal to convert the reference signal into a reference reflection signal having a frequency of 2.5KHz to 3.5KHz, preferably 3KHz, and derives an amplitude coefficient. Process (S30)).

In addition, the amplitude conversion module 140 superimposes the reference reflected signal and the trigger signal according to the amplitude coefficient to derive the first delay time, and overlaps the 3K reflected signal and the trigger signal obtained by converting the reference reflected signal into the square wave according to the amplitude coefficient. To derive a second delay time (fourth step S40).

In addition, the phase difference measurement module 150 superimposes the reference reflection signal and the 3K reflection signal with the trigger signal according to the amplitude coefficient, and measures the phase difference between the reference reflection signal and the trigger point as a third delay time and between the 3K reflection signal and the trigger point. The phase difference is measured by the fourth delay time to derive the phase difference between the reference reflected signal and the 3K reflected signal (S50).

The reflection signal correction module 160 derives the average of the derived phase differences as the correction phase difference to correct phases of the reference reflection signal and the 3K reflection signal (S60).

In detail, referring to step S40, the reference reflection signal and the trigger signal generated by the trigger comparator are superimposed according to an amplitude coefficient (S41), and the reference signal between the reference reflection signal and the trigger signal according to [Equation 4] is described. Deriving a delay time (S42), converts the reference reflected signal into a square wave (S43), superimposes the 3K reflected signal and the trigger signal converted to the square wave according to the amplitude coefficient (S44), according to [Equation 4] A second delay time between the 3K reflected signal and the trigger signal is derived (S45).

Further, referring to FIG. 7, the S50 process is described in detail. The reference reflection signal and the 3K reflection signal are superimposed with the trigger signal according to the amplitude coefficient (S51), and the phase difference between the reference reflection signal and the trigger point is expressed by Equation 4]. According to the third delay time (S52), the phase difference between the 3K reflected signal and the trigger point is measured by the fourth delay time according to [Equation 4] (S53), and the phase difference between the reference reflected signal and the 3K reflected signal It is derived through [Equation 5] (S54).

As described above and described with reference to a preferred embodiment for illustrating the technical idea of the present invention, the present invention is not limited to the configuration and operation as shown and described as described above, it is a deviation from the scope of the technical idea It will be understood by those skilled in the art that many modifications and variations can be made to the invention without departing from the scope of the invention. Accordingly, all such suitable changes and modifications and equivalents should be considered to be within the scope of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a diagram showing the configuration of an error correction system due to a laser reflection signal level variation according to the present invention.

2 is a view showing the relationship between the components of the error correction system caused by the laser reflection signal level variation in accordance with the present invention.

3 is a diagram illustrating that the amplitude conversion module according to the present invention derives first and second time delays according to a superimposition and a trigger signal between a reference reflection signal and a 3K reflection signal.

FIG. 4 is a diagram illustrating a phase difference measurement module according to the present invention, which derives a phase difference by measuring third and fourth time delays according to an overlap between a reference reflected signal and a 3K reflected signal and a trigger signal; FIG.

5 is a flowchart illustrating a method of compensating an error due to a change in laser reflection signal level according to the present invention.

6 is a flowchart illustrating a fourth process of the error correction method according to the laser reflection signal level variation according to the present invention in detail.

7 is a flowchart illustrating in detail a fifth process of the error correction method according to the variation of the laser reflection signal level according to the present invention;

** Description of symbols for the main parts of the drawing **

100: error correction system due to laser reflection signal level variation

110: laser output module 120: reflected signal receiving module

130: reflection signal mixing module 140: amplitude conversion module

150: phase difference measurement module 160: reflection signal correction module

Claims (8)

In the error correction system by the variation level of the laser reflection signal, A laser output module (110) radiating a laser signal for measuring a distance from the target object to the target object; A reflection signal receiving module 120 which receives the reflection signal reflected from the target object and halves it in half and simultaneously converts it into digital; A reflection signal mixing module 130 for adding the laser signal and the half-time signal to convert the reflection signal into a reference reflection signal and deriving an amplitude coefficient; The first delay time is derived by superimposing the reference reflection signal and the trigger signal according to the amplitude coefficient, and the second delay is obtained by superimposing the trigger signal and the 3K reflection signal obtained by converting the reference reflection signal into a square wave according to the amplitude coefficient. An amplitude conversion module 140 for deriving time; The phase reflection between the reference reflection signal and the trigger point is measured as a third delay time by overlapping the reference reflection signal and the 3K reflection signal with the trigger signal according to the amplitude coefficient, and the phase difference between the 3K reflection signal and the trigger point is measured by a fourth delay time. A phase difference measuring module 150 measuring a delay time and deriving a phase difference between the reference reflected signal and the 3K reflected signal; And A reflection signal correction module 160 which derives an average of the phase differences as a correction phase difference to correct phases of the reference reflection signal and the 3K reflection signal; Error correction system by the laser reflection signal level variation comprising a. The method of claim 1, The reflection signal mixing module 130, And the laser signal and the half-hour signal are added and converted into a reference reflection signal having a frequency of 2.5KHz to 3.5KHz. The method of claim 1, The first to fourth delay time, It is derived through [Equation 4] by the overlap of the reference reflection signal, 3K reflection signal and the trigger signal according to the amplitude coefficient,

Is the trigger signal level,

Is the maximum level of the reference reflection signal,

Error correction system by the variation level of the laser reflection signal, characterized in that the period of each signal. [Equation 4]

The method of claim 1, The phase difference between the reference reflection signal and the 3K reflection signal is Derived through Equation 5, DV is a distance value, CV is a distance measurement value by the amplitude coefficient, t1 means the third delay time, t2 means the fourth delay time. Error correction system caused by laser reflection signal level fluctuation. [Equation 5]

The method of claim 1, The correction phase difference is error correction system by the laser reflection signal level variation, characterized in that derived through [Equation 6]. [Equation 6]

In the error correction method by the laser reflection signal level variation, A first step of emitting a laser signal to the target object; Receiving a reflected signal reflected from the target object by the laser signal and halving and digitizing it by half; A third step of adding the laser signal and the reflected signal to convert the laser signal into a reference reflected signal having a frequency of 3 KHz and deriving an amplitude coefficient; The first delay time is derived by superimposing the reference reflection signal and the trigger signal generated by the trigger fertilizer according to the amplitude coefficient, and the 3K reflection signal and the trigger signal obtained by converting the reference reflection signal into a square wave according to the amplitude coefficient. A fourth process of overlapping to derive a second delay time; The phase reflection between the reference reflection signal and the trigger point is measured as a third delay time by overlapping the reference reflection signal and the 3K reflection signal with the trigger signal according to the amplitude coefficient, and the phase difference between the 3K reflection signal and the trigger point is measured by a fourth delay time. A fifth step of deriving a phase difference between the reference reflected signal and the 3K reflected signal by measuring with a delay time; And A sixth process of correcting phases of the reference reflected signal and the 3K reflected signal by deriving the average of the derived phase differences as a corrected phase difference; Error correction method according to the laser reflection signal level variation, comprising a. The method of claim 6, The fourth process, Superimposing the reference reflection signal and the trigger signal according to the amplitude coefficient; Deriving a first delay time between the reference reflection signal and a trigger signal according to Equation 4; Converting the reference reflected signal into a square wave; Superimposing the 3K reflected signal converted into a square wave and the trigger signal according to the amplitude coefficient; And Deriving a second delay time between the 3K reflected signal and the trigger signal according to Equation 4; Error correction method according to the laser reflection signal level variation, comprising a. [Equation 4]

The method of claim 6, The fifth process, Superimposing the reference reflected signal and the 3K reflected signal with the trigger signal according to the amplitude coefficient; Measuring a phase difference between the reference reflection signal and a trigger point with a third delay time according to Equation 4; Measuring a phase difference between the 3K reflected signal and a trigger point with a fourth delay time according to Equation 4; And Deriving a phase difference between the reference reflected signal and the 3K reflected signal through [Equation 5]; Error correction method according to the laser reflection signal level variation, comprising a. [Equation 5]

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