WO2022062984A1 - Crosstalk resistance processing method and apparatus for laser radar, and storage medium - Google Patents

Abstract

A crosstalk resistance processing method and apparatus (100) for a laser radar, and a memory (150). The laser radar comprises a laser device, and a receiving end which is configured to detect a target region that a laser emitted by the laser device can irradiate. The crosstalk resistance processing method comprises: when a laser device of a laser radar for detecting a target region emits light, performing crosstalk detection on a non-target region by using a receiving end of the laser radar (S401); when an echo is detected, determining, according to detected echo data, whether there is echo interference at a laser device corresponding to the receiving end (S402); and when it is determined that there is echo interference at the laser device corresponding to the receiving end, performing crosstalk resistance processing, the crosstalk resistance processing comprising at least one of the following: adjusting a scanning repetition frequency of the laser device corresponding to the receiving end, and adjusting a laser scanning mode of the laser device corresponding to the receiving end (S403).

Description

Anti-crosstalk processing method, device and storage medium for lidar

The present disclosure is based on an earlier Chinese patent application with application number: 202011030706.4 and an application date of September 27, 2020, and claims the priority of the earlier Chinese patent application, the entire contents of which are hereby contained This application is incorporated by reference.

technical field

The present invention relates to the technical field of laser radar but is not limited to the technical field of laser radar, and in particular relates to a laser radar anti-crosstalk processing method, device and storage medium.

Background technique

Lidar is a device that achieves ranging and grayscale measurement of the target object by sending a laser to the surface of the object, and then measuring the arrival time of the reflected beam. A point cloud image is an image formed by a collection of echoes within the entire field of view after the lidar scans and emits laser light and then acquires the echoes. But when multiple lidars work together, or when different lasers of a lidar emit lasers at the same time, different pulses will interfere with each other, resulting in erroneous images on the point cloud map.

In the related art, a spatial staggering method is generally adopted to solve this problem, that is, the spatial ranges of the emission between different lasers are different, or the time staggering method, that is, the emission times of different lasers are different, and so on. However, these implementation methods not only ineffective, but also reduce the measurement efficiency and increase the complexity of laser detection.

SUMMARY OF THE INVENTION

Embodiments of the present invention provide an anti-crosstalk processing method, device, and storage medium for a laser radar.

An aspect of the embodiments of the present invention provides an anti-crosstalk processing method for a laser radar, where the laser radar includes a laser source and a receiving end configured to receive laser light emitted by the laser source, and the method includes: in the laser light source During the time period when the source does not scan, the receiver is used for crosstalk detection; when the echo of crosstalk is detected in the unscanned space area of the receiver, it is determined according to the detected echo data for the laser source to emit Whether there is echo interference in the laser light emitted by the laser source; when it is determined that there is echo interference to the laser light emitted by the laser source, anti-crosstalk processing is performed, and the anti-crosstalk processing operation includes at least one of the following: adjusting the laser source to detect time repetition frequency, and adjust the laser scanning mode of the laser source.

Another aspect of the present invention provides an anti-crosstalk processing method for a laser radar. The laser radar includes a laser source and a receiving end configured to detect a target area that can be irradiated by laser light emitted by the laser source. The method includes: For the spatial area in the target area that is not scanned by the laser, use the receiving end to perform crosstalk detection; when the crosstalk echo is detected in the time period when the laser source is not scanning, according to the detected echo The wave data determines whether there is echo interference for the laser light emitted by the laser source; when it is determined that there is echo interference for the laser light emitted by the laser source, anti-crosstalk processing is performed, and the anti-crosstalk processing operation includes the following At least one of: adjusting the scanning repetition frequency of the laser source, and adjusting the laser scanning mode of the laser source.

Another aspect of the present invention provides an anti-crosstalk processing method for a laser radar. The laser radar includes a laser source and a receiving end configured to detect a target area that can be irradiated by laser light emitted by the laser source, wherein the laser radar includes:

For the spatial area in the target area that is not scanned by the laser, use the receiving end to perform crosstalk detection;

When the echo of the crosstalk is detected in the unscanned space area of the receiving end, determine whether there is echo interference to the laser light emitted by the laser source according to the detected echo data;

When it is determined that there is echo interference to the laser light emitted by the laser light source, anti-crosstalk processing is performed.

Another aspect of the present invention provides an anti-crosstalk processing method for a laser radar, the laser radar comprising a laser source and a receiving end configured to receive laser light emitted by the laser source, the method comprising:

During the time period when the laser source is not scanning, the receiving end is used for crosstalk detection;

When the echo of the crosstalk is detected in the time period when the laser source is not scanning, determine whether there is echo interference to the laser light emitted by the laser source according to the detected echo data;

When it is determined that there is echo interference to the laser light emitted by the laser light source, anti-crosstalk processing is performed.

In yet another aspect of the embodiments of the present invention, there is provided an anti-crosstalk processing device for lidar, including a memory, a processor, and a computer program stored in the memory and executable on the processor, and the processor executes The computer program implements the steps of the anti-crosstalk processing method for lidar according to any one of the above embodiments.

Another aspect of the embodiments of the present invention provides a computer-readable storage medium, where the computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, implements any one of the foregoing embodiments. The steps of the anti-crosstalk processing method for lidar.

The beneficial effects of the anti-crosstalk processing method, device and storage medium for laser radar according to the embodiments of the present invention include:

First, use the receiving end of the laser to detect crosstalk when the laser is not emitting, or use the receiving end of the lidar to detect the crosstalk in the non-target area when the laser of the lidar detecting the target area is emitting, and then when the echo is detected, according to The detected echo data determines whether the laser has echo interference. Finally, when it is determined that the laser has echoes of crosstalk, adjust the repetition frequency of the laser when detecting the target area, or adjust the laser scanning mode of the laser, that is, the laser scanning method. The embodiment can effectively remove the interference of other devices by changing the repeat frequency or scanning mode affected by crosstalk, ensure the stability of the anti-crosstalk processing of the lidar, improve the quality of the point cloud image, and increase the adaptability of the lidar to complex laser environments.

Description of drawings

FIG. 1 is a schematic diagram of an implementation flowchart of a laser radar anti-crosstalk processing method provided by an embodiment of the present invention;

FIG. 2 is a schematic flowchart of a specific implementation of step S102 in FIG. 1;

3 is a schematic diagram of a target area, a protection area and a non-target area provided by an embodiment of the present invention;

FIG. 4 is a schematic diagram of an implementation flowchart of another laser radar anti-crosstalk processing method provided by an embodiment of the present invention;

FIG. 5 is a schematic structural diagram of another laser radar anti-crosstalk processing apparatus provided by an embodiment of the present invention.

detailed description

In the following description, for the purpose of illustration rather than limitation, specific details such as specific system structures and technologies are set forth in order to provide a thorough understanding of the embodiments of the present invention. However, it will be apparent to those skilled in the art that the present invention may be practiced in other embodiments without these specific details.

In order to illustrate the technical solutions of the present invention, the following specific embodiments are used for description.

Referring to FIG. 1 , a schematic diagram of an implementation flow of an embodiment of the laser radar anti-crosstalk processing method provided in this embodiment is described in detail as follows:

Step S101 , in a time period when the laser source does not scan, use the receiving end to perform crosstalk detection.

In one embodiment, the laser source may be at least one of the lasers in the plurality of lidars.

In one embodiment, the laser source may also be at least one of a plurality of lasers in a lidar.

When multiple laser radars work together, or when different lasers of one laser emit lasers at the same time, the different pulses emitted will interfere with each other, resulting in the formation of wrong images on the point cloud map, but the anti-crosstalk effect of spatial or temporal staggering is not ideal. . Therefore, this embodiment provides a technology for anti-crosstalk processing between multiple laser radars or between multiple lasers of one laser radar.

Exemplarily, since the lidar is not in the scanning state all the time, there is a period of non-scanning, for example, the retrace period of the MEMS galvanometer of the MEMS (Micro-Electro-Mechanical System, micro-electromechanical system) lidar does not scan.

Exemplarily, when the lidar is powered on normally, for example, when the mechanical rotating lidar, MEMS, and other solid-state lidars are powered on normally, the time period when the lidar does not emit light is used. At this time, the receiving end of the lidar still receives signals. The receiving end detects the crosstalk signal, and then in this embodiment, the signal at the receiving end is collected, analyzed and data processed, so as to realize the active detection of the laser crosstalk of the laser radar.

Step S102, when an echo is detected, determine whether there is echo interference to the laser light emitted by the laser source according to the detected echo data.

When an echo signal of active detection is received, it is judged whether there is a crosstalk echo in the echo signal received by the current lidar detection target area. For example, in the case of a lidar including a laser, the lidar scans the target area with a repeated frequency signal. When the target area is not scanned (non-scanning period), if the receiving end of the lidar receives the echo signal, then It means that the laser is crosstalked by other lasers, which is the crosstalk between multiple lidars. For example, when a lidar includes multiple lasers, each laser scans the corresponding target area with its own repeating frequency signal. If there is a wave signal, it means that the laser is crosstalked by other lasers, which is the crosstalk between multiple lasers in the lidar.

For the case of continuous multiple frames, it is necessary to perform crosstalk echo statistics on the entire frame of data, and determine whether the laser itself is crosstalked by other lasers by comparing the number of crosstalk echoes with the ratio of the total number of detections. Determine whether there is crosstalk. If the accumulated multiple frames have crosstalk, for example, more than one-third of the data frames have crosstalk, then it can be determined that the own laser is crosstalked by other lasers.

Step S103, when it is determined that there is echo interference to the laser light emitted by the laser source, anti-crosstalk processing is performed.

There are many ways of anti-crosstalk processing operations. An exemplary anti-crosstalk processing operation may include at least one of the following: adjusting the repetition frequency of the laser source when detecting the target area, adjusting the laser scanning mode of the laser source, but it is worth noting that anti-crosstalk processing The processing operations are not limited to adjusting the repetition frequency of the laser source when detecting the target area and/or adjusting the laser scanning pattern of the laser source.

In this embodiment, the laser is used to actively detect the target area in the state of not receiving echoes during the non-scanning period, actively detect the interference of the surrounding environment, and determine whether there is a crosstalk echo in the surrounding environment that needs to be processed by the own laser, so as to adjust the parameters of the own laser , for example, repeat frequency adjustment, or adjust the laser scanning method of its own laser (or lidar) to perform anti-crosstalk processing, that is, an effective anti-crosstalk processing method can be selected according to the actual situation of the laser, to remove the interference of other equipment, and realize the anti-crosstalk processing method. Laser crosstalk detection in complex environments ensures the stability of laser radar anti-crosstalk processing, and at the same time ensures the quality of point cloud images and increases the adaptability to complex laser environments.

In one embodiment, the laser source may be a single APD (Avalanche Diode) receiver system laser.

The single APD receiving method is generally used for coaxial lasers. The receiving end rotates the receiving lens at the front end or other MEMS galvanometers, etc., so that the transmitting and receiving are in the same field of view, so that as long as the laser is emitting light, the APD has been working. . Therefore, active crosstalk detection can only be performed when the laser is not emitting light, and at a certain moment, a single APD can only detect a partial area in the entire field of view, that is, the preset area (also called "target area") in this embodiment. .

In one embodiment, the specific implementation process of step S102 includes:

Step S201 , when an echo signal is detected, determine whether there is echo interference in each frame of data according to the number of detected echoes and the ratio of the total number of detections.

Step S202, it is determined whether there is echo interference to the laser source according to the number of frames in which echo interference exists.

For example, the echo judgment is performed on the X frame data, the number of echoes of the X frame data is detected, and the detected echo number of the first frame data and the ratio of the total detection times are both greater than the preset value, then it is determined that the first frame data is subject to Crosstalk, it is finally determined that one-third of the frames suffer from crosstalk, and it is determined that the laser has echo interference. Among them, when the echo signal is detected, the area or the frame data is detected N _all times, that is, N _all is the total number of detections. For example, crosstalk detection is performed on the area A, and if the echo signal is received, the area A Perform N _all times of detection, and receive N _all times of echo signals.

In one embodiment, the specific implementation process of step S201 may include:

Set J echo intervals, the weight corresponding to the j (j∈[1,2,...,J]) echo interval is A _j , and the number of detected echoes corresponds to the jth echo interval The number of detections is N _j .

Calculate the total weighted detection times when the number of detected echoes is within J echo intervals

according to

Determine whether there is echo interference in each frame of data, where N _all is the total number of detections.

For example, the total number of detections is 10 times, and 4 echo intervals are set, namely interval a, interval b, interval c and interval d. When the third detection is performed, the number of received echoes is within the interval a, then N ₃ The weight is A _a , when the 4th and 5th detections, the received echo numbers are all within the b interval, then the weights of N ₄ and N ₅ are both A _b , when the 8th and 9th detections , the received echo numbers are all within the c interval, then the weights of N ₈ and N ₉ are both A _c , when the 10th detection, the received echo numbers are within the d interval, then the weight of N ₁₀ is both Ad , then T=A _a 1+A _b 2+A _c 2+A _d 1, according to (A _a 1+A _b 2+A _c 2+A _d 1 ₎ /10 Determine whether there is echo interference in each frame of data.

For example, the total number of detections is 10 times, and 4 echo intervals are set, namely interval a, interval b, interval c and interval d. The number of echoes received during the 1st, 2nd, and 3rd detections is within interval a. , when the number of echoes received in the 4th, 5th, 6th, and 7th detections is in the b interval, when the 8th and 9th detections are received, the number of echoes received is in the c interval. When the 10th detection When the number of echoes received is in the interval d, then T=A _a 3+A _b 4+A _c 2+A _d 1, according to (A _a 3+A _b 4+A _c 2+A _d ·1)/10 determines whether there is echo interference in each frame of data.

For example, the total number of detections is 10 times, and 4 echo intervals are set, namely interval a, interval b, interval c and interval d. The number of echoes received during the 1st, 2nd, and 3rd detections is within interval a. , when the number of echoes received in the 4th, 5th, 6th and 7th detections are all within the b interval, then T=A _a 3+A _b 4, according to (A _a 3+A _b 4) /10 Determines whether there is echo interference in each frame of data.

In one embodiment, setting J echo intervals, and the specific implementation process of the j (j∈[1,2,...,J]) echo interval corresponding to the weight A _j includes:

Set the interval weight less than or equal to the first threshold as A1, the interval weight greater than the first threshold and less than the second threshold as A2, and the interval weight greater than or equal to the second threshold as A3;

If the interval greater than the first threshold and less than the second threshold includes multiple values, a linear interpolation method is used to give weight to the number of echoes Tk in the interval greater than the first threshold and less than the second threshold

T _low is the first threshold, and T _high is the second threshold.

In practical applications, for the case where the number of detected echoes is less than the first threshold, it is based on the spatial geometry scanned by multiple lidars. situation, then there will be a situation less than the first threshold. In one embodiment, the first threshold and the second threshold in this embodiment may be determined according to actual laser radar data collection and after learning and training, and different values may also be set according to the result of scene collection, for example, may be 1 and 2 and so on.

Exemplarily, in the case of multiple lidars, when the current lidar detects an echo, the current lidar performs N _all times of detection in the area to determine whether the current lidar is subject to crosstalk. Exemplarily, for the total number of detections of the entire received signal of the current lidar is N _all , each time the crosstalk echo detection is performed, it is divided into different intervals according to the number of crosstalk echoes received by the lidar, and different intervals are assigned different values. Weights. Exemplarily, it can be divided into 2 intervals according to the number of crosstalk echoes. If the number of crosstalk echoes detected in N _a times is T _low , then the weight is set to a, and if the number of crosstalk echoes detected in N _b times is greater than or equal to T _high , set the weight to b, and then count the total number of crosstalk echoes. The final total weighted detection times T=a·N _a +b·N _b , that is, the more is larger, the greater the possibility of crosstalk to the lidar, so the weight b is greater than the weight a.

Setting different weights can reduce false detection to a certain extent. For example, when the number of crosstalk echoes is 1, the possibility of crosstalk is small, so the probability of false detection is relatively high, so reduce the weight, but when the number of crosstalk echoes is 2 , the possibility of crosstalk is high, and the probability of false detection is relatively low, so the weight is increased, which can avoid the false detection of the algorithm caused by the raised noise floor to a certain extent.

It can characterize the proportion of crosstalk echoes in the whole frame of data. if

It means that the current laser is disturbed, then repeat the frequency switching of the current laser beam, otherwise the current laser is not disturbed, and β is the detection coefficient.

By setting β to different values, the repetition frequency switching sensitivity of the laser can be adjusted. In the actual use process, β needs to be adjusted according to the actual situation to determine the re-frequency switching sensitivity. Repeat frequency switching sensitivity can be understood as: the relationship between the severity of frame data contamination by crosstalk and the need to be switched, the higher the sensitivity, the less tolerance for crosstalk. The more tolerant it is to be crosstalked, for example, when the crosstalk ratio reaches a certain level, it will be switched.

In one embodiment, the repetition frequency switching method of this embodiment can obtain the repetition frequency with the smallest proportion of crosstalk echoes by performing algorithm detection and analysis on different repetition frequency signals. Further, when it is determined that the laser has echo interference, the repetition frequency of the laser when detecting the target area is adjusted to be the repetition frequency with the smallest proportion of crosstalk echoes.

In one embodiment, the method may further include:

When echoes are detected, all M frames of data are processed

judge.

according to

Determine whether the laser source has echo interference, where Wi is the weight of the _i -th frame of data, T _i is the total weighted detection times of the i-th frame of data,

For the total number of times of crosstalk detection for the i-th frame of data, that is, this embodiment may not specifically limit the total number of times of each frame of data detection, and the total number of times of each frame of data detection may be the same or different.

Exemplarily, in the case of performing crosstalk judgment on consecutive multiple frames of data, the re-frequency switching sensitivity can be adjusted according to the actual situation. To reduce the sensitivity, the crosstalk coefficient can be calculated by setting the weight of each frame of data, and whether the laser has echo interference is determined by judging the crosstalk coefficient. If there is echo interference, the current repetition frequency signal of the laser is switched.

Exemplarily, if three frames of data are judged, N _all times of detection is performed on each frame. Assuming that the first frame of data is detected

The value is less than β, β is the detection coefficient, but the

The value is much larger than β, then the crosstalk situation can be finally determined by weight calculation. For the continuous detection of M frames, the weight set for each frame of data is W _i , then the final crosstalk coefficient is

If this value satisfies β _total > β, then it is determined that the current laser is crosstalked.

In one embodiment, in the repetition frequency switching method of this embodiment, the repetition frequency with the smallest crosstalk coefficient can be obtained by performing algorithm detection and analysis on each frame of data. Further, when it is determined that the laser has echo interference, the repetition frequency of the laser when detecting the target area is adjusted to be the repetition frequency with the smallest crosstalk coefficient. The repetition frequency selection in this embodiment may be to select a new repetition frequency for each frame of data, that is, to perform repetition frequency switching when one frame of data is judged to be disturbed, or to select a new repetition frequency after continuous M frames of judgment. The evaluation criterion for the selection of repetition frequency can be based on the proportion of crosstalk echoes.

The repetition frequency of the frame data corresponding to the smallest value is the new repetition frequency.

In one embodiment, for the case of continuously judging the number of frames N, this embodiment may adopt a method of introducing variation or randomness to the number of consecutive frames N, that is, the value of N may vary regularly or randomly. For example, N frames of data are used in the first judgment, and N+1 frames of data can be used in the next judgment, which increases to N _max and then becomes N again; for example, N frames of data are used for the first judgment, In the next judgment, an appropriate number of frames is selected according to a specific encoding (M-sequence or other encoding methods). Such a method can greatly increase the randomness, avoid mutual switching between multiple devices, and avoid the unstable state of anti-crosstalk processing.

In one embodiment, before adjusting the repetition frequency of the laser source when detecting the target area in step S103, the method further includes: storing the detected echo data as a crosstalk data set in a manner corresponding to each repetition frequency, and in the In the crosstalk data set, the repetition frequencies corresponding to the echo data are sorted according to the echo number of each echo data.

Step S103 may include: adjusting the repetition frequency of the laser source when detecting the target area to the repetition frequency corresponding to the minimum number of echoes in the crosstalk data set, that is, if it is determined that its own laser has been crosstalked by other lasers, it needs to pass Pick the repetition frequency for anti-jamming processing.

Exemplarily, if an echo is detected in step S102, the detected signal is recorded as a crosstalk data set, and the data set is used to select the repetition frequency with the smallest crosstalk in the next step. Then, select different repetition frequencies from the historical crosstalk data set for algorithm detection, that is, detect signals with different repetition frequencies, and each repetition frequency can obtain a detection result. When the laser itself does not emit light, if the repetition frequency is used If there is no crosstalk at the frequency, the detection result should be no echo; if there is crosstalk, there is an echo in the detection result. The above-mentioned historical crosstalk data set can be updated in real time according to the M frames of data set in the above embodiment, that is, if every M frame of data is detected, only the crosstalk data set of the latest M frames of data is retained to reduce the historical state. Interfere with the current handover strategy.

Therefore, it is possible to first count how many signals in the echo signal set received by the current laser scanning target area are erroneously detected as echoes, that is, to determine how many repetition frequency signals have crosstalk; Sorting: in the crosstalk data set, the repetition frequencies corresponding to the echo data are sorted according to the echo numbers of the echo data, and the repetition frequency state with the smallest echo number is selected as the new repetition frequency state. If a laser corresponds to a repetition frequency, if the laser is subject to crosstalk, switch the repetition frequency of the laser; if a frame of data corresponds to a repetition frequency, when the frame data is subject to crosstalk, switch the repetition frequency of the frame data.

In one embodiment, when multiple lidars (three or more lidars) work together, two lidars periodically jump to each other's states when they work, resulting in unstable final states. In this case, a correction can be added to the repetition frequency switching strategy, and a sleep mechanism can be introduced for devices whose repetition frequency has not reached a stable state after being switched repeatedly (which can be adjusted according to the actual situation, generally more than half of the total repetition frequency) At least one switching cycle, that is, one or more switching cycles are suspended, and then repeat frequency switching is continued. That is to say, if there is a situation where the crosstalk echo has not been significantly reduced after switching to the selected repetition frequency for many times in a row, then the sleep processing is performed (because other devices may also be in the switching state at this time), that is, It may not be processed first, and after a few frames or other lidar devices are stabilized, algorithm judgment and repetition frequency switching processing are performed again to increase the adaptability of the anti-crosstalk processing method of this embodiment.

This embodiment further includes: when it is determined that the laser source has echo interference, adjusting the laser scanning mode of the current laser source. Exemplarily, the actual design is carried out according to the crosstalked echo time and space area detected in step S102, avoiding the crosstalked space time position, and performing anti-crosstalk processing. There are many crosstalk echoes at the scanning angle, and the lidar can be controlled to scan the airspace of this angle at a staggered time in the next scan, and change it to scan this airspace at other times, that is, by adjusting the scanning timing in the scanning period to avoid crosstalk.

For the radar of the APD array receiving system, in addition to adjusting the scanning repetition frequency of the laser source as described in any of the foregoing embodiments, the method of turning off the APD in a specific space area at a specific time can also be used for anti-crosstalk processing.

In the above-mentioned laser radar anti-crosstalk processing method, by changing the repetition frequency of the crosstalk, or changing the laser scanning method (for example, adjusting the turn-off time of each APD in the APD array), it is possible to effectively realize the communication between multiple laser radars. The anti-crosstalk processing between the multiple emitting lasers of the lidar has high robustness and can dynamically adapt to various complex environments, ensuring the stability of the anti-crosstalk processing of the lidar, and improving the quality of the point cloud image. It also increases the adaptability of lidar to complex laser environments.

Based on the above-mentioned laser radar anti-crosstalk processing, referring to FIG. 4 , this embodiment also provides a laser radar anti-crosstalk processing method, as follows:

Step S401 , for the spatial area in the target area that is not scanned by the laser, use the receiving end that receives the echo on the lidar side to perform crosstalk detection.

In this embodiment, the signal at the receiving end is collected, analyzed and data processed. At this time, the echo signal received by the receiving end is the echo signal of the unscanned area of the laser, that is, the laser radar (laser source) that detects the laser scanning area is used to detect the current Active detection of unscanned areas. The space area not scanned by the laser here is the aforementioned non-target space.

Step S402, when an echo is detected, determine whether there is echo interference to the laser light emitted by the laser source according to the detected echo data.

Step S403, when it is determined that there is echo interference to the laser light emitted by the laser source, anti-crosstalk processing is performed, and the anti-crosstalk processing operation includes at least one of the following: adjusting the scanning repetition frequency of the laser source, and adjusting the laser scanning mode of the laser source.

In one embodiment, the target area includes a scanned spatial area, a protection area located around the scanned spatial area, and an unscanned spatial area. FIG. 3 shows an example.

In one embodiment, the laser of this embodiment may be an APD array receiver system radar. Further, using the APD array of the APD array receiving system radar to perform crosstalk detection for the space area not scanned by the laser may include: when it is determined that there is echo interference to the laser light emitted by the laser source, adjusting the APD receiving system in the APD array receiving system radar. The off time for each APD of the array.

Exemplarily, when the APD array receiving system radar is working, the APD array corresponding to the scanned space area in the APD array receiving system radar receives echo signals from the scanned space area, and the APD array receiving system radar corresponding to the protection system receives echo signals from the scanned space area. The area APD array stops receiving the echo signal from the protection area, and the APD array in the APD array receiving system radar corresponding to the unscanned space area receives the echo signal from the unscanned space area.

The range of the protection area is determined according to the receiving field of view of the APD array receiving system radar and the point spread function of the transmitting beam of the APD array receiving system radar, so that the APD array can receive echo signals for the scanned space area and at the same time the unidentified Scan the spatial area for crosstalk detection.

In one embodiment, the point spread function of the transmit beam of the APD array receiver regime radar is the primary determinant of the extent of the protected area.

The unscanned spatial area of this embodiment is not the non-target area of the APD array receiving system radar, but is another APD channel of the APD array relative to the scanned spatial area. For example, to detect point A, the APD channel of the APD array receiving system in the radar is the scanned spatial area APD array, and the APD channel not responsible for detecting point A is the non-scanned spatial area APD array, but the APD array receiving system The entire detection area of the radar is much larger than point A.

Exemplarily, in the APD array receiving system, the radar performs signal reception and data processing for the unscanned space area. For details, see Figure 3. When the APD array receiving system radar scans the area 1 (the scanned space area) in the figure, the surrounding area 2 is set as the protection area, and the APD array responsible for area 2 does not enter the active detection statistics at the scanning time. (ie, do not receive echo signals), the APD arrays responsible for area 3 (non-scanning spatial area) all perform active detection of signal reception and data processing statistics.

The range of the protection area can be determined according to the divergence angle and resolution of the APD array itself in the protection area. For example, the range of area 1 (the scanned spatial area) corresponds to the divergence angle of the laser beam of the APD array in the scanned spatial area. The range of the protection area is the sum of the spatial resolution and beam divergence angle of the APD array in the protection area, and can also be determined according to the point spread function of the laser beam of the APD array in the protection area. In one embodiment, in this embodiment, the size of the direction angle at which the laser beam energy is attenuated to less than -20 dB of the peak energy plus the angle of one resolution unit is the range of the protection area.

The range of the unscanned space area (area 3) depends on the maximum detection space range that the APD array receiver system radar can cover, and then subtracts the scanned space area (area 1) and the protection area (area 2).

Since the range of the protection area is determined according to the receiving field of view of the APD array receiving system radar and the point spread function of the transmitting beam of the APD array receiving system radar, and the protection of a resolution unit is set, the scanned space area can be guaranteed. It does not interfere with each other when scanning with non-scanning spatial areas.

For the specific implementation process of step S402 and step S403, reference may be made to the introduction of the above-mentioned embodiment, which will not be repeated here.

Those skilled in the art can understand that the size of the sequence number of each step in the above-mentioned embodiment does not mean the sequence of execution, and the execution sequence of each process should be determined by its function and internal logic, rather than the implementation process of the embodiment of the present invention. constitute any limitation.

This embodiment also provides a schematic diagram of a laser radar anti-crosstalk processing apparatus 100 . As shown in FIG. 5 , the laser radar anti-crosstalk processing apparatus 100 of this embodiment includes: a processor 140 , a memory 150 , and a computer program 151 stored in the memory 150 and executable on the processor 140 , such as a laser Procedure for Radar Anti-Crosstalk Processing Method.

The processor 140 implements the steps in the above-mentioned embodiments of the laser radar anti-crosstalk processing method when executing the computer program 151 on the memory 150, for example, steps 101 to 103 shown in FIG. 1 or steps 401 to 403 shown in FIG. 4 . .

Exemplarily, the computer program 151 may be divided into one or more modules/units, and the one or more modules/units are stored in the memory 150 and executed by the processor 140 to complete the this invention. The one or more modules/units may be a series of computer program instruction segments capable of performing specific functions, and the instruction segments are used to describe the execution process of the computer program 151 in the lidar anti-crosstalk processing apparatus 100 .

The laser radar anti-crosstalk processing apparatus 100 may include, but is not limited to, a processor 140 and a memory 150 . Those skilled in the art can understand that FIG. 5 is only an example of the laser radar anti-crosstalk processing device 100 , and does not constitute a limitation on the laser radar anti-crosstalk processing device 100 , and may include more or less components than those shown in the figure, or combinations thereof Certain components, or different components, for example, the laser radar anti-crosstalk processing apparatus 100 may also include input and output devices, network access devices, buses, and the like.

The processor 140 may be a central processing unit (Central Processing Unit, CPU), or other general-purpose processors, digital signal processors (Digital Signal Processor, DSP), application specific integrated circuit (Application Specific Integrated Circuit, ASIC), Off-the-shelf programmable gate array (Field-Programmable Gate Array, FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. A general purpose processor may be a microprocessor or the processor may be any conventional processor or the like.

The memory 150 may be an internal storage unit of the lidar anti-crosstalk processing apparatus 100 , such as a hard disk or a memory of the lidar anti-crosstalk processing apparatus 100 . The memory 150 may also be an external storage device of the lidar anti-crosstalk processing apparatus 100, such as a plug-in hard disk, a smart memory card (Smart Media Card, SMC), a secure digital (Secure Digital, SD) card, flash memory card (Flash Card), etc. Further, the memory 150 may also include both an internal storage unit of the lidar anti-crosstalk processing apparatus 100 and an external storage device. The memory 150 is used for storing the computer program and other programs and data required by the laser radar anti-crosstalk processing apparatus 100 . The memory 150 may also be used to temporarily store data that has been output or will be output.

Those skilled in the art can clearly understand that, for the convenience and simplicity of description, only the division of the above-mentioned functional units and models is used as an example for illustration. In practical applications, the above-mentioned functions can be allocated to different functional units, Module completion, that is, dividing the internal structure of the device into different functional units or modules to complete all or part of the functions described above. Each functional unit and module in the embodiment may be integrated in one processing unit, or each unit may exist physically alone, or two or more units may be integrated in one unit, and the above-mentioned integrated units may adopt hardware. It can also be realized in the form of software functional units. In addition, the specific names of the functional units and modules are only for the convenience of distinguishing from each other, and are not used to limit the protection scope of the present application. For the specific working processes of the units and modules in the above-mentioned system, reference may be made to the corresponding processes in the foregoing method embodiments, which will not be repeated here.

The present invention implements all or part of the processes in the methods of the above embodiments, which can be implemented by hardware modules or by instructing relevant hardware through a computer program, and the computer program can be stored in a computer-readable storage medium. , when the computer program is executed by the processor, the steps of the above-mentioned method embodiments can be implemented. Wherein, the computer program includes computer program code, and the computer program code may be in the form of source code, object code, executable file or some intermediate form, and the like. The computer-readable medium may include: any entity or device capable of carrying the computer program code, recording medium, U disk, removable hard disk, magnetic disk, optical disk, computer memory, read-only memory (ROM, Read-Only Memory) , Random Access Memory (RAM, Random Access Memory), electric carrier signal, telecommunication signal and software distribution medium, etc. It should be noted that the content contained in the computer-readable media may be appropriately increased or decreased according to the requirements of legislation and patent practice in the jurisdiction, for example, in some jurisdictions, according to legislation and patent practice, the computer-readable media Excluded are electrical carrier signals and telecommunication signals.

The above embodiments are only used to illustrate the technical solutions of the present invention, but not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: The recorded technical solutions are modified, or some technical features thereof are equivalently replaced; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present invention, and should be included in the present invention. within the scope of protection.

Claims (24)

1. An anti-crosstalk processing method for a laser radar, the laser radar includes a laser source and a receiving end configured to detect a target area that can be irradiated by laser light emitted by the laser source, wherein the laser radar includes:

   For the spatial area in the target area that is not scanned by the laser, use the receiving end to perform crosstalk detection;

   When the echo of the crosstalk is detected in the unscanned space area of the receiving end, determine whether there is echo interference to the laser light emitted by the laser source according to the detected echo data;

   When it is determined that there is echo interference to the laser light emitted by the laser source, anti-crosstalk processing is performed, and the anti-crosstalk processing operation includes at least one of the following: adjusting the scanning repetition frequency of the laser source, adjusting the The laser scanning method of the source.
2. The anti-crosstalk processing method for lidar according to claim 1, wherein,

   The target area includes a scanned spatial area, a protection area located around the scanned spatial area, and the unscanned spatial area.
3. The anti-crosstalk processing method for lidar according to claim 1, wherein,

   The lidar is an APD array receiving system radar;

   For the unscanned space area, use the APD array of the APD array receiving system radar to perform crosstalk detection;

   Use the APD array of the APD array receiving system radar to perform crosstalk detection, including:

   When it is determined that there is echo interference to the laser light emitted by the laser source, the off time of each APD of the APD receiving array in the radar of the APD array receiving system is adjusted.
4. The anti-crosstalk processing method for lidar according to claim 2, wherein the range of the protection area is based on the receiving field of view of the APD array receiving system radar and the point spread function of the transmitting beam of the APD array receiving system radar It is determined that the APD array can perform crosstalk detection on the unscanned spatial region while receiving echo signals on the scanned spatial region.
5. The anti-crosstalk processing method for lidar according to any one of claims 1 to 4, wherein when the echo of the crosstalk is detected in the unscanned space area of the receiving end, according to the detected echo data Determine whether there is echo interference to the laser light emitted by the laser source, including:

   When detecting echoes of crosstalk, determine whether there is echo interference in each frame of data according to the number of echoes detected and the ratio of the total number of detections;

   Whether there is echo interference for the laser source is determined according to the number of frames in which there is echo interference.
6. The anti-crosstalk processing method for lidar according to claim 5, wherein when the echo of crosstalk is detected, whether there is echo interference in each frame of data is determined according to the number of detected echoes and the ratio of the total number of detections ,include:

   Set J echo intervals, the weight corresponding to the j (j∈[1,2,...,J]) echo interval is A _j , and the number of detected echoes corresponds to the jth echo interval The number of detections is N _j ;

   Calculate the total weighted detection times corresponding to when the number of detected echoes is within the J echo intervals

   

   according to

   

   Determine whether there is echo interference in each frame of data, where N _all is the total number of detections.
7. The anti-crosstalk processing method for lidar according to claim 5, wherein, in the setting of J echo intervals, the weight corresponding to the j (j∈[1,2,...,J])th echo interval is A _j , including:

   Set the interval weight less than or equal to the first threshold as A1, the interval weight greater than the first threshold and less than the second threshold as A2, and the interval weight greater than or equal to the second threshold as A3;

   If the interval greater than the first threshold and less than the second threshold includes multiple values, a linear interpolation method is used to give weight to the number of echoes Tk in the interval greater than the first threshold and less than the second threshold

   

   T _low is the first threshold, and T _high is the second threshold.
8. The anti-crosstalk processing method for lidar as claimed in claim 5, further comprising:

   When echoes are detected, all M frames of data are processed

   

   judge;

   according to

   

   Determine whether there is echo interference for the laser light emitted by the laser source, wherein, Wi is the weight of the _ith frame of data, T _i is the total weighted detection times of the ith frame of data,

   

   is the total number of crosstalk detections performed on the data of the i-th frame.
9. The anti-crosstalk processing method for lidar according to any one of claims 1 to 4, wherein before the adjusting the repetition frequency of the laser source during detection, the method further comprises:

   The detected echo data is stored as a crosstalk data set in a manner corresponding to each repetition frequency. In the crosstalk data set, the repetition frequency corresponding to the echo data is performed according to the echo number of each echo data sort.
10. The anti-crosstalk processing method for lidar according to claim 9, wherein adjusting the repetition frequency of the laser source comprises:

    The repetition frequency of the laser source during detection is adjusted to the repetition frequency corresponding to the smallest number of the echoes in the crosstalk data set.
11. An anti-crosstalk processing method for a laser radar, wherein the laser radar includes a laser source and a receiving end configured to receive laser light emitted by the laser source, and the method includes:

    During the time period when the laser source is not scanning, the receiving end is used for crosstalk detection;

    When the echo of the crosstalk is detected in the time period when the laser source is not scanning, determine whether there is echo interference to the laser light emitted by the laser source according to the detected echo data;

    When it is determined that there is echo interference to the laser light emitted by the laser source, anti-crosstalk processing is performed, and the anti-crosstalk processing operation includes at least one of the following: adjusting the scanning repetition frequency of the laser source, adjusting the The laser scanning method of the source.
12. The anti-crosstalk processing method for lidar according to claim 11, wherein:

    The laser source is at least one of the lasers provided in the plurality of lidars; or,

    The laser source is at least one of a plurality of lasers provided in one of the lidars.
13. The anti-crosstalk processing method for lidar according to claim 12, wherein,

    For each laser, configure the receiver in one-to-one correspondence.
14. The anti-crosstalk processing method for lidar according to claim 11, wherein:

    For each laser, configure the receivers in such a way that one laser corresponds to multiple receivers.

    In this case, the plurality of receiving ends corresponding to the same laser each perform crosstalk detection for different predetermined areas.
15. The anti-crosstalk processing method for lidar according to any one of claims 11 to 14, wherein, when the echo of the crosstalk is detected in the time period when the laser source is not scanning, according to the detected echo The data determines whether there is echo interference to the laser light emitted by the laser source, including:

    When detecting echoes of crosstalk, determine whether there is echo interference in each frame of data according to the number of echoes detected and the ratio of the total number of detections;

    Whether there is echo interference for the laser source is determined according to the number of frames in which there is echo interference.
16. The anti-crosstalk processing method for lidar according to claim 15, wherein, when the echo of crosstalk is detected, whether there is echo interference in each frame of data is determined according to the number of detected echoes and the ratio of the total number of detections ,include:

    Set J echo intervals, the weight corresponding to the j (j∈[1,2,...,J]) echo interval is A _j , and the number of detected echoes corresponds to the jth echo interval The number of detections is N _j ;

    Calculate the total weighted detection times corresponding to when the number of detected echoes is within the J echo intervals

    

    according to

    

    Determine whether there is echo interference in each frame of data, where N _all is the total number of detections.
17. The anti-crosstalk processing method for lidar according to claim 15, wherein, in the setting of J echo intervals, the weight corresponding to the j (j∈[1,2,...,J])th echo interval is A _j , including:

    Set the interval weight less than or equal to the first threshold as A1, the interval weight greater than the first threshold and less than the second threshold as A2, and the interval weight greater than or equal to the second threshold as A3;

    If the interval greater than the first threshold and less than the second threshold includes multiple values, a linear interpolation method is used to give weight to the number of echoes Tk in the interval greater than the first threshold and less than the second threshold

    

    T _low is the first threshold, and T _high is the second threshold.
18. [Correction 27.09.2021 under Rule 91]
    The anti-crosstalk processing method for lidar as claimed in claim 15, further comprising:
    When echoes are detected, all M frames of data are processed

    

    judge;
    according to

    

    Determine whether there is echo interference for the laser light emitted by the laser source, wherein, Wi is the weight of the _ith frame of data, T _i is the total weighted detection times of the ith frame of data,

    

    is the total number of crosstalk detections performed on the data of the i-th frame.
19. [Correction according to Rule 91 on 27.09.2021] The anti-crosstalk processing method for lidar according to any one of claims 11 to 14, wherein, before the adjustment of the repetition frequency of the laser source during detection, the method further comprises:

    The detected echo data is stored as a crosstalk data set in a manner corresponding to each repetition frequency. In the crosstalk data set, the repetition frequency corresponding to the echo data is performed according to the echo number of each echo data. sort.
20. [Correction 27.09.2021 according to Rule 91] The anti-crosstalk processing method for lidar according to claim 18, wherein adjusting the repetition frequency of the laser source comprises:

    The repetition frequency of the laser source during detection is adjusted to the repetition frequency corresponding to the smallest number of the echoes in the crosstalk data set.
21. [Correction 27.09.2021 according to Rule 91] An anti-crosstalk processing device for lidar, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor The steps of implementing the anti-crosstalk processing method for lidar according to any one of claims 1 to 10 or 11 to 19 are implemented when the computer program is executed.
22. [Correction 27.09.2021 according to Rule 91] A computer-readable storage medium storing a computer program, wherein the computer program, when executed by a processor, implements claims 1 to 10 or 11 to 19 The steps of any one of the anti-crosstalk processing methods for lidars.
23. [Correction 27.09.2021 according to Rule 91] An anti-crosstalk processing method for a lidar, the lidar comprising a laser source and a receiver configured to detect a target area that can be irradiated by laser light emitted by the laser source, wherein, include:

    For the spatial area in the target area that is not scanned by the laser, use the receiving end to perform crosstalk detection;

    When the echo of the crosstalk is detected in the unscanned space area of the receiving end, determine whether there is echo interference to the laser light emitted by the laser source according to the detected echo data;

    When it is determined that there is echo interference to the laser light emitted by the laser light source, anti-crosstalk processing is performed.
24. [Correction 27.09.2021 according to Rule 91] A method for anti-crosstalk processing for lidar, wherein the lidar includes a laser source and a receiver configured to receive laser light emitted by the laser source, and the method includes:

    During the time period when the laser source is not scanning, the receiver is used for crosstalk detection;

    When the echo of the crosstalk is detected in the time period when the laser source is not scanning, determine whether there is echo interference to the laser emitted by the laser source according to the detected echo data;

    When it is determined that there is echo interference to the laser light emitted by the laser light source, anti-crosstalk processing is performed.

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