CN-121978699-A - High-dynamic high-frame-rate signal processing method of long-distance single-photon laser radar

CN121978699ACN 121978699 ACN121978699 ACN 121978699ACN-121978699-A

Abstract

The invention discloses a high-dynamic high-frame-rate signal processing method of a long-distance single-photon laser radar, and belongs to the field of laser radar signal processing. The method comprises the steps of obtaining the latest ranging results of N laser pulses from the single-photon laser radar to output target average distance and target average speed accumulated by a low frame frequency, obtaining the latest ranging results of the single laser pulses, calculating a distance threshold range and a predicted distance value based on the target average distance and the target average speed, and judging the number of the target ranging results meeting the distance threshold range to determine the high frame rate single-pulse distance by combining the predicted distance value. Therefore, the method and the device can calculate the distance threshold range and the predicted distance value through the target average distance and the target average speed accumulated by the low frame frequency, and output the high frame frequency single pulse distance by combining the latest single laser pulse target ranging result, so that the high frame frequency single pulse distance can be output for the high-dynamic target to be measured, and the high frame frequency distance measurement requirement can be met.

Inventors

HE YINGBO
WANG LI
SHI GUANGQING
WU YUN
GUO SHAOGANG
YUAN LI
ZHANG CHENGHAO

Assignees

北京控制工程研究所

Dates

Publication Date: 20260505
Application Date: 20260304

Claims (10)

1. The high-dynamic high-frame-rate signal processing method for the long-distance single-photon laser radar is applied to an on-board processing platform and is characterized by comprising the following steps of: Obtaining the latest ranging results of N laser pulses from the single-photon laser radar to output the target average distance and the target average speed accumulated by a low frame frequency; acquiring a target ranging result of the latest single laser pulse, and calculating a distance threshold range and a predicted distance value based on the target average distance and the target average speed; And judging the quantity of the target ranging results meeting the distance threshold range so as to determine the high-frame-rate single pulse distance by combining the predicted distance value.
2. The method of claim 1, wherein obtaining the latest ranging results of the N laser pulses from the single photon lidar to output the target average distance and the target average speed accumulated at a low frame rate comprises: obtaining the latest ranging results of N laser pulses by utilizing a sliding window; determining a target average distance accumulated by a low frame frequency from the ranging results of the N laser pulses by using the bi-phase histogram; and determining the target average speed by using an exponential weighted average method based on the target average distance.
3. The method of claim 2, wherein determining the target average distance for low frame rate integration from the ranging results of the N laser pulses using the bi-phase histogram comprises: constructing a first histogram and a second histogram, wherein each histogram contains a plurality of pre-opening intervals, and counting the number of laser echo counts contained in each pre-opening interval; Obtaining a current target average speed, taking the minimum ranging result of the ranging results of N laser pulses as the starting distance of the first histogram, determining the step length of the first histogram and the second histogram based on the current target average speed, initializing the corresponding count number of each pre-opening interval, and determining the starting distance of the second histogram based on the starting distance and the step length of the first histogram to finish parameter updating; traversing each ranging result of N laser pulses, determining the interval of each ranging result in the first histogram and the second histogram, and adding 1 to the count number of the corresponding pre-opening interval when each ranging result falls into one pre-opening interval; determining a maximum count number in the first histogram and a maximum count number in the second histogram respectively; Comparing the maximum count number in the first histogram with the maximum count number in the second histogram, and taking the larger value of the maximum count number in the first histogram and the maximum count number in the second histogram as a target value; If the target value is greater than or equal to a preset threshold value, determining that the radar signal has a target, and calculating a distance average value of a pre-opening interval corresponding to the histogram corresponding to the target value as a target average distance accumulated by a low frame frequency; and if the target value is smaller than the preset threshold value, determining that no target exists in the radar signal.
4. The method of claim 2, wherein said determining a target average speed using an exponentially weighted average based on said target average distance comprises: acquiring the current average distance of the target and the corresponding time thereof; calculating an instantaneous target speed based on the current target average distance and the corresponding time thereof and the target average distance output at the last moment and the corresponding time thereof; A target average speed is determined based on the instantaneous target speed and an exponentially weighted coefficient.
5. The method of claim 1, wherein the calculating a distance threshold range and a predicted distance value based on the target average distance and target average speed comprises: the lower distance threshold is calculated by the following formula: R low =R n +v tn Delay1 The upper distance threshold is calculated by the following formula: R up =R n +v tn Delay2 The predicted distance value is calculated by the following formula: R p = R n +v tn N/(2 freq) Wherein R low is the lower limit of the distance threshold, R n is the target average distance, v tn is the target average speed, delay1, delay2 are the corresponding Delay coefficients, R up is the upper limit of the distance threshold, R p is the predicted distance value, N is the number of the selected latest laser pulses, and freq is the laser frequency.
6. The method of claim 1, wherein determining the number of target ranging results that satisfy the range threshold range to determine a high frame rate monopulse distance in combination with the predicted range value comprises: if the target ranging results are not in the range of the distance threshold value, the current high frame rate ranging is not output; If only 1 target ranging result falls within the range of the range threshold, the target ranging result is a high frame rate single pulse distance output; And if a plurality of target ranging results fall in the range of the distance threshold value, selecting the target ranging result with the smallest absolute value of the difference between the target ranging result and the predicted distance value as a high frame rate single pulse distance to output.
7. A high dynamic high frame rate signal processing device of a long-range single photon laser radar, which is disposed on a satellite-borne processing platform and is configured to implement the steps of the method of any one of claims 1-6, and is characterized by comprising: The low frame frequency unit is used for acquiring the latest ranging results of N laser pulses from the single-photon laser radar so as to output a target average distance and a target average speed accumulated at a low frame frequency; The calculating unit is used for obtaining a target ranging result of the latest single laser pulse and calculating a distance threshold range and a predicted distance value based on the target average distance and the target average speed; and the high frame frequency unit is used for judging the number of the range threshold ranges met in the target ranging result so as to determine a high frame frequency single pulse distance by combining the predicted range value.
8. A computer device, characterized in that it comprises a memory for storing a computer program and a processor for executing the computer program stored on the memory for carrying out the steps of the method according to any of the preceding claims 1-6.
9. A computer-readable storage medium, characterized in that the storage medium has stored therein a computer program which, when executed by a processor, implements the steps of the method of any of claims 1-6.
10. A computer program product comprising a computer program which, when executed by a processor, implements the steps of the method of any of claims 1-6.

Description

High-dynamic high-frame-rate signal processing method of long-distance single-photon laser radar Technical Field The invention relates to the technical field of laser radar signal processing, in particular to a high-dynamic high-frame-rate signal processing method of a long-distance single-photon laser radar. Background Under the constraint of space resources, the on-orbit remote laser range radar adopts a scheme of a high-energy pulse laser and a high-sensitivity single photon detector in scheme design. Single photon detectors have high sensitivity, but are susceptible to noise interference, large clutter noise and difficult signal extraction. In particular, when the space satellite-borne platform is used, the movement speed of the object to be measured is high (high dynamic state), and the movement speed in the sight line direction can reach kilometers per second. Meanwhile, in combination with the use requirement, the ranging result output by the laser radar is required to have a high frame rate (> 20 Hz). The existing long-distance single-photon laser radar signal processing method can only process low-frame frequency signals, is suitable for a target to be detected moving at a low speed, cannot be applied to a high-dynamic target to be detected scene, and cannot output high-frame frequency processing signals. Therefore, it is desirable to provide a high dynamic high frame rate signal processing method for a long-range single photon lidar. Disclosure of Invention In order to solve the problems that the existing signal processing method of the long-distance single-photon laser radar can only process low-frame frequency signals, is suitable for a target to be detected moving at a low speed, cannot be applied to a high-dynamic target scene to be detected, and cannot output high-frame-rate processing signals, the embodiment of the invention provides a high-dynamic high-frame-rate signal processing method of the long-distance single-photon laser radar. In one aspect, a high dynamic high frame rate signal processing method of a long-distance single photon laser radar is provided, and is applied to an on-board processing platform, and the method comprises the following steps: Obtaining the latest ranging results of N laser pulses from the single-photon laser radar to output the target average distance and the target average speed accumulated by a low frame frequency; acquiring a target ranging result of the latest single laser pulse, and calculating a distance threshold range and a predicted distance value based on the target average distance and the target average speed; And judging the quantity of the target ranging results meeting the distance threshold range so as to determine the high-frame-rate single pulse distance by combining the predicted distance value. On the other hand, a high dynamic high frame rate signal processing device of a long-distance single photon laser radar based on the steps described in any method embodiment of the specification is provided, and the device is arranged on an on-board processing platform and comprises: The low frame frequency unit is used for acquiring the latest ranging results of N laser pulses from the single-photon laser radar so as to output a target average distance and a target average speed accumulated at a low frame frequency; The calculating unit is used for obtaining a target ranging result of the latest single laser pulse and calculating a distance threshold range and a predicted distance value based on the target average distance and the target average speed; and the high frame frequency unit is used for judging the number of the range threshold ranges met in the target ranging result so as to determine a high frame frequency single pulse distance by combining the predicted range value. In another aspect, a computer device is provided, the computer device comprising a memory for storing a computer program and a processor for executing the computer program stored on the memory to implement the steps of the method described above. In another aspect, a computer readable storage medium is provided, in which a computer program is stored which, when being executed by a processor, carries out the steps of the method described above. In another aspect, a computer program product is provided, comprising a computer program which, when executed by a processor, implements the steps of the method described above. The technical scheme provided by the invention has at least the following beneficial effects: Through the dual-channel architecture, the average distance of the low frame rate and the transient distance of the high frame rate can be output simultaneously, and the method is blank in the international field at present aiming at the high frame rate (> 20 Hz) signal processing of a long-distance (> 200 km) and high-speed moving target (> 1 km/s), and can calculate a distance threshold range and a predicted distance value through the target average distance and the