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CN-116359878-B - Waveform characteristic parameter calculation method of full-waveform laser radar

CN116359878BCN 116359878 BCN116359878 BCN 116359878BCN-116359878-B

Abstract

The invention discloses a waveform characteristic parameter calculation method of a full waveform laser radar, which is suitable for the full waveform laser radar adopting a single pulse type time-of-flight ranging method; the method is characterized in that discretization waveform data containing echo pulses are calculated from peak values, characteristic parameters of waveform arrival time are calculated by adopting a scheme for realizing optimization on a chip, in order to simplify operation steps, the initial time is set to 0, the real initial time is added to a final result, waveform data of adjacent time are respectively added to the left and right after the current iteration result is obtained, next iteration is carried out, and when the value of the newly added waveform data is smaller than 2/3 of the peak value and the difference value between the result of the arrival time and the last iteration is smaller than the preset minimum precision, or the value of the newly added waveform data is smaller than the preset threshold value, the iteration is stopped. The method can obtain the measurement result with extremely high precision, and has the advantages of easy on-chip implementation and quick real-time operation.

Inventors

  • WANG CHUNYONG
  • ZHOU YUNDONG
  • YAN WEI
  • JI YUNJING
  • LAI JIANCHENG
  • LI ZHENHUA

Assignees

  • 南京理工大学

Dates

Publication Date
20260505
Application Date
20230305

Claims (7)

  1. 1. The waveform characteristic parameter calculation method of the full-waveform laser radar is characterized by comprising the following steps of: Step 1, setting a preset threshold value z=eta+lambda-sigma according to the statistical characteristics of the background noise in the echo, wherein eta is the mean value of the background noise, sigma is the variance of the background noise, and lambda is a variance coefficient; Step 2, the laser radar transmits pulse signals, the pulse transmission time is recorded as 0 time, the receiving end digitally samples the received echo signals to obtain original waveform data containing pulse echoes, the maximum value z max in the waveform data is judged, all data between the maximum value and the minimum value of the corresponding time of z max are extracted, the data are recorded as z j , j=1, 2,3, the number of the extracted data is recorded as n, and the minimum value of the corresponding time of all the maximum values is recorded as t 0 ; Step 3, calculating the following 6 coefficients according to the number n of the data: the coefficients and data values are taken into the following calculation formula: obtaining the pulse arrival time mu calculated at this time; Step 4, adding one piece of original waveform data on each of the left and right sides of the data used in the previous iteration, denoted as z j , j=1, 2,3,.. the minimum value in the corresponding moment of the obtained data is marked as t 0 , the step 3 is repeated to obtain a new operation result mu ' and the difference |mu ' -mu| between the new operation result mu ' and the last iteration result is calculated; step 5, if the two new data added in step 4 are smaller than 2*z max /3 and |mu' -mu| is smaller than the preset precision, or the two new data added in step 4 are smaller than the preset threshold z, the iteration is ended, otherwise, step 4 is repeated; And 6, obtaining a final characteristic parameter mu.
  2. 2. The method for calculating the waveform characteristic parameters of the full-waveform lidar according to claim 1, wherein in the step 1, when the lidar has not emitted a pulse signal, the noise floor data obtained by the analog-to-digital converter obtains the statistical distribution characteristics thereof, and a preset threshold is set according to the statistical distribution characteristics.
  3. 3. The method for calculating the waveform characteristic parameters of the full-waveform lidar according to claim 1, wherein in step 2, calculation is started from the maximum value of the echo data, and all data from the minimum time to the maximum time among the times at which the maximum value occurs are taken as the data of the first iteration.
  4. 4. The method for calculating the waveform characteristic parameters of the full-waveform laser radar according to claim 1, wherein the coefficient calculation formula in step 3 is: according to the characteristics of the pulse laser radar echo, the value of the minimum moment in the data participating in the operation does not influence the relative time difference between the final result and the minimum moment, so that t 0 =0, and the coefficient calculation formula is simplified to be: and finally, adding t 0 to the operation result to obtain the correct characteristic parameters.
  5. 5. An electronic device comprising a memory, a processor and a computer program stored on the memory and executable on the processor, characterized in that the processor implements the steps of the method according to any of claims 1-4 when the program is executed.
  6. 6. A computer readable storage medium, on which a computer program is stored, characterized in that the program, when being executed by a processor, implements the steps of the method according to any of claims 1-4.
  7. 7. A computer program product comprising a computer program, characterized in that the computer program, when being executed by a processor, implements the steps of the method of any of claims 1-4.

Description

Waveform characteristic parameter calculation method of full-waveform laser radar Technical Field The invention belongs to the technical field of laser detection, and particularly relates to a waveform characteristic parameter calculation method of a full-waveform laser radar. Background The laser radar is used as a combination of the traditional radar technology and the modern laser technology, solves the problems of insufficient space-time resolution, limited detection range and the like of the traditional radar technology by utilizing the characteristics of laser, and has wide application in the aspects of territorial mapping, military reconnaissance, industrial measurement and the like. Common laser radar ranging methods can be divided into a triangular ranging method, an interference ranging method and an optical time ranging method, wherein the pulse optical time ranging method in the optical time ranging method is a mainstream laser radar ranging method at present due to the advantages of long detection distance, high efficiency, good ranging precision and the like. The laser radar adopting the pulse type light line time ranging method generally only adopts a simple simulation method to process echoes, such as a fixed threshold method, a peak detection method and the like, and the full-wave analysis method is a brand-new waveform processing method which has resolution, sensitivity and accuracy which are incomparable with the simulation method, however, the full-wave analysis method adopted in the existing laser radar can only be realized in an off-line calculation mode, depends on a high-performance computer, cannot be realized on a chip, has long complex calculation time in the calculation process, and has no advantages in the aspects of portability and instantaneity. Based on the background, the invention provides a waveform characteristic parameter calculation method of a full-waveform laser radar, which can realize real-time full-wave analysis on a chip in a simple data processing mode and realize rapid real-time operation on the premise of ensuring accuracy. Disclosure of Invention The invention aims to provide a waveform characteristic parameter calculation method of a full-waveform laser radar. The technical solution for achieving the purpose of the invention is that in a first aspect, the invention provides a waveform characteristic parameter calculation method of a full waveform laser radar, which comprises the following steps: Step 1, setting a preset threshold value z=eta+lambda-sigma according to the statistical characteristics of the background noise in the echo, wherein eta is the mean value of the background noise, sigma is the variance of the background noise, and lambda is a variance coefficient; Step 2, the laser radar transmits pulse signals, the pulse transmission time is recorded as 0 time, the receiving end digitally samples the received echo signals to obtain original waveform data containing pulse echoes, the maximum value z max in the waveform data is judged, all data between the maximum value and the minimum value of the corresponding time of z max are extracted, the data are recorded as z j, j=1, 2,3, the number of the extracted data is recorded as n, and the minimum value of the corresponding time of all the maximum values is recorded as t 0; Step 3, calculating the following 6 coefficients according to the number n of the data: the coefficients and data values are taken into the following calculation formula: obtaining the pulse arrival time mu calculated at this time; Step 4, adding one piece of original waveform data on each of the left and right sides of the data used in the previous iteration, denoted as z j, j=1, 2,3,.. the minimum value in the corresponding moment of the obtained data is marked as t 0, the step 3 is repeated to obtain a new operation result mu ' and the difference |mu ' -mu| between the new operation result mu ' and the last iteration result is calculated; step 5, if the two new data added in step 4 are smaller than 2*z max/3 and |mu' -mu| is smaller than the preset precision, or the two new data added in step 4 are smaller than the preset threshold z, the iteration is ended, otherwise, step 4 is repeated; And 6, obtaining a final characteristic parameter mu. Further, in step 1, when the laser radar has not sent out a pulse signal, the noise floor data obtained by the analog-to-digital converter obtains the statistical distribution characteristics thereof, and a preset threshold is set according to the statistical distribution characteristics. Further, in step 2, calculation is started from the maximum value of the echo data, and all data from the minimum time to the maximum time of the time at which the maximum value occurs are taken as the data of the first iteration. Further, the coefficient calculation formula in the step 3 is as follows: according to the characteristics of the pulse laser radar echo, the value of the minimum moment in the data