Laser radar detection method, detection system, computer equipment, medium and product

Abstract

The invention relates to a laser radar detection method, a detection system, computer equipment, a medium and a product. The method comprises the steps that pulse driving signals are obtained in a detection period, laser pulse signals are generated according to the pulse driving signals, the time interval of adjacent pulse signals in the pulse driving signals is set randomly, and the minimum value of the time interval of the pulse signals is larger than the recovery time of a photon detector. According to the invention, the laser pulse signal is sent after the laser pulse signal is generated, and the echo light signal of the laser pulse signal reflected by the target object is received. Photon counting is carried out in the echo optical signal, the arrival time of each photon is determined, and an echo pulse signal is obtained according to the number of photons at each arrival time; and finally, determining a distance parameter of the target object according to the correlation between the pulse driving signal and the echo pulse signal. According to the invention, the probability of finding a target in target object detection can be improved, and the problems of low detection efficiency and long detection period in a traditional laser radar detection method are solved.

Description

Technical Field

[0001] This application relates to the technical field of lidar detection, and particularly to a lidar detection method, a detection system, a computer device, a medium, and a product. Background Art

[0002] Lidar detection is a technology that uses laser beams for measurement and detection. Lidar detection has high accuracy and good resolution and is widely used in engineering fields such as aerial surveying, ships, and small unmanned aerial vehicles. When performing lidar detection, a laser pulse is usually first emitted, and then the echo signal of the laser pulse reflected from the target object is measured. Information related to the target object is obtained by processing the echo signal. Through multiple cyclic detections, lidar can achieve continuous detection and tracking of the target object.

[0003] However, in current lidar detection methods, when detecting a target object at a long distance, the interval between laser pulse emissions is large and the detection period is long. In addition, the number of photons in the echo signal decreases as the detection distance increases, and the echo signal is easily interfered by noise, resulting in low detection efficiency. Summary of the Invention

[0004] Based on this, in view of the above technical problems, it is necessary to provide a lidar detection method, a detection system, a computer device, a medium, and a product that can reduce the detection period and improve the detection efficiency.

[0005] In a first aspect, this application provides a lidar detection method, which includes:

[0006] Within a detection period, a laser generator obtains a pulse drive signal and generates a laser pulse signal according to the pulse drive signal. The time interval between adjacent pulse signals in the pulse drive signal is randomly set, and the minimum value of the time interval between adjacent pulse signals is greater than the recovery time of the photon detector.

[0007] A transceiver common optical system transmits the laser pulse signal and receives the echo optical signal of the laser pulse signal reflected by the target object. A photon number resolving detector performs photon counting on the echo optical signal, determines the arrival time of each photon, and obtains an echo pulse signal according to the number of photons at each arrival time.

[0008] A processor determines the distance parameter of the target object according to the correlation between the pulse drive signal and the echo pulse signal.

[0009] In some of these embodiments, before the transceiver common optical system transmits the laser pulse signal, the method further includes:

[0010] The processor determines the target area to be scanned and determines the set of scanning paths corresponding to the target area;

[0011] The processor traverses the set of scanning paths to determine multiple emission directions of the laser pulse signal;

[0012] The transceiver shared optical system transmits the laser pulse signal, including:

[0013] The transceiver shared optical system transmits multiple laser pulse signals according to multiple emission directions, wherein the multiple laser pulse signals are used to obtain multiple echo pulse signals, and the multiple emission directions, the multiple laser pulse signals, and the multiple echo pulse signals correspond one-to-one;

[0014] The processor determines the distance parameter of the target object according to the correlation between the pulse drive signal and the echo pulse signal, including:

[0015] The processor determines multiple distance parameters of the target object according to the correlation between the pulse drive signal and the multiple echo pulse signals, and the multiple distance parameters of the target object are used to determine the motion trajectory of the target object.

[0016] In some embodiments, obtaining the pulse drive signal includes:

[0017] The signal generator generates an original pulse sequence, the original pulse sequence includes multiple original pulses, the time interval between adjacent original pulses is randomly set, and the minimum value of the time interval between adjacent original pulses is greater than the recovery time of the photon detector;

[0018] The signal generator generates a pulse drive signal according to the original pulse sequence, and transmits the pulse drive signal to the laser generator. The time interval between adjacent pulse signals in the pulse drive signal is the same as the time interval between adjacent original pulses in the original pulse sequence.

[0019] In some embodiments, obtaining the echo pulse signal according to the number of photons at each arrival time includes:

[0020] The photon number resolving detector resolves the number of photons at each arrival time, determines the echo electric pulse corresponding to the current arrival time according to the number of photons at each arrival time, and obtains the echo pulse signal according to the echo electric pulses corresponding to all arrival times.

[0021] In some embodiments, the processor determines the distance parameter of the target object according to the correlation between the pulse drive signal and the echo pulse signal, including:

[0022] The processor performs cross-correlation processing on the pulse drive signal and the echo pulse signal to obtain a cross-correlation signal for characterizing the correlation result;

[0023] The processor determines the distance parameter according to the cross-correlation signal.

[0024] In some embodiments, the processor determines the distance parameter according to the cross-correlation signal, including:

[0025] The processor counts the maximum peak and the second maximum peak in the cross-correlation signal;

[0026] When the maximum peak is unique, the processor determines whether the ratio between the maximum peak and the second maximum peak is greater than a preset value;

[0027] If so, the processor obtains the target time corresponding to the maximum peak, determines the distance parameter of the target object according to the target time, and determines the target motion trajectory of the target object according to the distance parameter.

[0028] In some embodiments, the method further includes:

[0029] If the cross-correlation signal includes multiple maximum peaks, or the ratio between the maximum peak and the second maximum peak is less than the preset value, return to the step of obtaining the pulse drive signal, and the laser generator performs detection again.

[0030] In a second aspect, the present application further provides a lidar detection system, and the system includes:

[0031] A laser generator, configured to obtain a pulse drive signal within a detection period and generate a laser pulse signal according to the pulse drive signal, wherein the time interval between adjacent pulse signals in the pulse drive signal is randomly set, and the minimum value of the time interval between adjacent pulse signals is greater than the recovery time of the photon detector;

[0032] A transceiver common optical system, configured to transmit the laser pulse signal and receive the return light signal reflected by the target object from the laser pulse signal;

[0033] A photon number resolving detector, configured to perform photon counting in the return light signal, determine the arrival time of each photon, and obtain a return pulse signal according to the number of photons at each arrival time;

[0034] A processor, configured to determine the distance parameter of the target object according to the correlation between the pulse drive signal and the return pulse signal.

[0035] In a third aspect, the present application further provides a computer device, including a memory and a processor, where the memory stores a computer program, and when the processor executes the computer program, the steps of the method provided in any one of the first aspects are implemented.

[0036] In a fourth aspect, the present application further provides a computer-readable storage medium, on which a computer program is stored, and when the computer program is executed by a processor, the steps of the method provided in any one of the first aspects are implemented.

[0037] In a fifth aspect, the present application further provides a computer program product, including a computer program which, when executed by a processor, implements the steps of the method provided in any one of the above first aspects.

[0038] The embodiments of the present disclosure may / at least have the following advantages:

[0039] In the above lidar detection method, detection system, computer device, medium and product, within one detection period, a pulse drive signal is acquired, and a laser pulse signal is generated according to the pulse drive signal. The time interval between adjacent pulse signals in the pulse drive signal is randomly set. After the laser pulse signal is generated in the present application, the laser pulse signal is sent, and the reflected light signal of the laser pulse signal reflected by the target object is received. Then, photon counting is performed on the reflected light signal, and the arrival time of each photon is determined. An echo pulse signal is obtained according to the number of photons at each arrival time. Finally, the distance parameter of the target object is determined according to the correlation between the pulse drive signal and the echo pulse signal.

[0040] The lidar detection method of the present application generates and emits multiple laser pulses with randomly set time intervals within one detection period, avoiding the problem that traditional lidar systems need to accumulate data for multiple detection periods, improving the detection ability of the lidar, increasing the anti-interference ability of the laser pulse signal, and increasing the probability of detecting a target in target object detection, solving the problems of low detection efficiency and long detection period in traditional lidar detection methods. At the same time, the present application performs photon number resolution on the received reflected light signal, determines the echo pulse signal according to the arrival time of each photon in the reflected light signal, and can effectively extract the echo signal by combining the signal of the photon number when processing the reflected light signal, reducing the interference of background noise and improving the detection efficiency of the lidar. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] In order to more clearly illustrate the technical solutions in the embodiments of the present application or related technologies, the following will briefly introduce the drawings required for use in the description of the embodiments or related technologies. Obviously, the following drawings are only some embodiments of the present application. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0042] Figure 1 It is a schematic flowchart of the lidar detection method in some embodiments;

[0043] Figure 2 It is a schematic flowchart of the lidar detection method in some other embodiments;

[0044] Figure 3 It is a schematic flowchart of the lidar detection and tracking in some embodiments;

[0045] Figure 4 It is a main performance comparison diagram with the traditional lidar detection method in some embodiments;

[0046] Figure 5 It is a structural diagram of a lidar detection system in some embodiments;

[0047] Figure 6 It is an internal structural diagram of a computer device in one embodiment. Detailed implementation manners

[0048] In order to make the objectives, technical solutions and advantages of the present application clearer and more understandable, the present application will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0049] A lidar detection system is a system that detects and tracks target objects through lidar detection methods. A lidar detection system generally includes a signal transmitting unit for transmitting laser signals, a signal receiving unit for receiving echo signals, and a signal processing unit for processing the received echo signals to obtain target detection results. When detecting and tracking a target object at a long distance through a lidar detection system, since the distance between the lidar detection system and the target object is far, the laser detection signal needs to accumulate data through multiple detection cycles to complete one measurement, resulting in a long detection cycle and low efficiency.

[0050] In view of the above problems, in some embodiments, as Figure 1 shown, a lidar detection method is proposed, including the following steps 102 to 106. Wherein:

[0051] Step 102, within one detection cycle, a laser generator obtains a pulse drive signal and generates a laser pulse signal according to the pulse drive signal. The time interval between adjacent pulse signals in the pulse drive signal is randomly set, and the minimum value of the time interval between adjacent pulse signals is greater than the recovery time of the photon detector.

[0052] The laser pulse signal is emitted by the laser generator in the lidar detection system, and is a signal that propagates along a specific direction and irradiates the surface of the target object. The laser pulse signal can be used to measure the distance parameters or motion trajectory of the target object.

[0053] Exemplarily, the laser generator generates a laser pulse signal under the drive of the pulse drive signal. The pulse drive signal is denoted as C s (t), and the pulse drive signal C s (t) is input to the input end of the laser generator, and the pulse drive signal C s(t)Generate a laser signal inside the laser generator and output an intermittent laser signal, i.e., a laser pulse signal, at the output end. Pulse drive signal C s (t)Comprises a plurality of pulse signals, and the time interval between adjacent pulse signals is randomly set. The laser pulse signal generated by the laser generator corresponds to the signal of the pulse drive signal. The laser pulse signal also comprises a plurality of laser pulses, and the time interval between adjacent laser pulses is also randomly set.

[0054] The minimum value of the time interval between adjacent pulse signals in the pulse drive signal is greater than the recovery time of the photon detector. Since the photon detector generally has a recovery time, the recovery time refers to the time when the photon detector can effectively detect photons again after photon detection. If the random value of the time interval between two adjacent pulse signals is less than the recovery time, then after the echo photons of the previous pulse signal are detected, the photon detector has not recovered yet. At this time, the echo photons of the next pulse signal come, and the next pulse photons cannot be detected by the photon detector, resulting in information loss. If the minimum value of the time interval between adjacent pulse signals is greater than the recovery time of the photon detector, the situation where the detection of the previous pulse signal shields the detection of the next pulse signal will not occur. Therefore, in this embodiment, the minimum value of the time interval between adjacent pulse signals in the pulse drive signal is set to be greater than the recovery time of the photon detector. Exemplarily, the photon detector can be a photon number resolving detector.

[0055] The laser pulse signal generated by this application avoids the problem of low detection efficiency of traditional lidar systems. It can emit multiple laser pulses with random time intervals within one detection cycle, avoiding the problem that traditional lidar systems need to accumulate data for multiple detection cycles, improving the detection ability of the lidar and increasing the anti-interference ability of the laser pulse signal.

[0056] Step 104: The transceiver common optical system transmits the laser pulse signal and receives the echo optical signal reflected by the target object from the laser pulse signal; the photon number resolving detector performs photon counting on the echo optical signal, determines the arrival time of each photon, and obtains the echo pulse signal according to the photon number at each arrival time.

[0057] The lidar detection system emits a laser pulse signal through the laser generator, the transceiver common optical system receives the echo optical signal reflected by the target object, and obtains the distance parameter of the target object through the analysis and processing of the echo optical signal by the photon number resolving detector and the processor.

[0058] Different from traditional lidar tracking or detection methods, the present application performs photon counting detection on the echo optical signal, obtains the arrival time of each photon during the detection time, and determines the echo pulse signal at the arrival time according to the number of photons at each arrival time. The detection and tracking of the target object are realized through signal processing of the echo pulse signal.

[0059] In this embodiment, by detecting the number of photons in the echo optical signal, compared with the traditional method that can only determine the echo pulse signal according to the presence or absence of photons, this embodiment can effectively extract the pulse information of the echo optical signal according to the number of photons, avoid the interference of background noise on the echo optical signal, and improve the detection efficiency of the target object.

[0060] Step 106, the processor determines the distance parameter of the target object according to the correlation between the pulse drive signal and the echo pulse signal.

[0061] The correlation is used to represent the similarity between the pulse drive signal C s (t) and the echo pulse signal. The relationship between the pulse drive signal C s (t) and the echo pulse signal can be described through the correlation. The distance parameter of the target object includes the target distance between the target object and the lidar, and angular parameters such as the azimuth angle and elevation angle detected by the lidar.

[0062] The correlation can be determined by performing a correlation operation on the pulse drive signal C s (t) and the echo pulse signal. When performing the correlation operation, the echo pulse signal can be first collected, and the echo pulse signal can be converted into an echo signal W(t) that is convenient for signal processing. The correlation processing is to slide and compare one signal with another signal at different time points to obtain an operation result that can characterize the similarity between the two signals, and then the distance parameter of the target object can be determined according to this operation result.

[0063] In the traditional lidar method, only one laser pulse is emitted in one detection cycle. To realize the detection of the target object, it is usually necessary to accumulate the data of multiple detection cycles, which is time-consuming.

[0064] The above lidar detection method can generate and emit multiple laser pulses with random time intervals within one detection cycle, avoiding the problem of data accumulation in multiple detection cycles required by traditional lidar systems. It can improve the detection ability of the lidar, increase the anti-interference ability of the laser pulse signal, and increase the probability of detecting a target in target object detection, solving the problems of low detection efficiency and long detection cycle in traditional lidar detection methods. At the same time, in this application, photon number resolution is performed on the received echo optical signal, and the echo pulse signal is determined according to the arrival time of each photon in the echo optical signal. Combining the signal of the photon number when processing the echo optical signal can effectively extract the echo signal, reduce the interference of background noise, and improve the detection efficiency of the lidar.

[0065] In some further embodiments, the lidar detection method is also used for motion trajectory detection. The motion trajectory detection method includes:

[0066] Before the transmit / receive shared optical system sends the laser pulse signal, the processor determines the target area to be scanned and determines the set of scanning paths corresponding to the target area;

[0067] The processor traverses the set of scanning paths to determine multiple emission directions of the laser pulse signal. The transmit / receive shared optical system sending the laser pulse signal includes: the transmit / receive shared optical system sends multiple laser pulse signals according to multiple emission directions, where the multiple laser pulse signals are used to obtain multiple echo pulse signals, and the multiple emission directions correspond one-to-one to the multiple laser pulse signals and the multiple echo pulse signals;

[0068] The processor determining the distance parameter of the target object according to the correlation between the pulse drive signal and the echo pulse signal includes: the processor determines multiple distance parameters of the target object according to the correlation between the pulse drive signal and the multiple echo pulse signals, and the multiple distance parameters of the target object are used to determine the motion trajectory of the target object.

[0069] The target area represents the area that the lidar needs to detect. The size and shape of the target area can be determined according to the scanning requirements. The set of scanning paths can be expressed as S(k), which is the set of paths when the lidar system scans the target area. The lidar system scans the target area according to the scanning paths in the set of scanning paths S(k) to ensure that the entire area is scanned and improve the detection effect.

[0070] Furthermore, the scanning path set S(k) can be determined by scanning methods such as equidistant spiral lines, equidistant hexagonal scanning lines, equidistant quadrilateral scanning lines, etc. The equidistant quadrilateral scanning line can be used for regular matrices or standard target areas in the shape of a long strip, and the scanning path design is simple. The equidistant hexagonal scan is performed in the form of a hexagonal grid, and the intervals and directions of the scanning lines are arranged along the edges of the hexagon to ensure that the distances between adjacent scanning lines are equal, which is suitable for scenarios that require efficient coverage of a large area and improved scanning accuracy. The equidistant spiral line is a spiral-shaped path, and the distance between each circle of scanning points remains constant, gradually covering the entire target area. Determining the scanning path set in the way of an equidistant spiral line can ensure uniform coverage of the entire area.

[0071] It can be understood that the present embodiment places no restrictions on the generation method of the scanning path. In practical applications, the scanning path generation method can be determined according to detection requirements such as the shape and size of the target area and the scanning detection accuracy. Taking the equidistant spiral line scan as an example, parameters such as the number of layers of the equidistant spiral line and the angular spacing between each adjacent scanning position are designed according to the size of the target area actually detected.

[0072] The emission direction of the laser pulse signal represents the direction in which the lidar emits the laser pulse signal. The lidar emits laser pulse signals with different emission angles to cover different parts of the target area. The emission direction can include the azimuth angle and elevation angle detected by the lidar. The emission direction corresponds to the scanning path. For example, a target scanning path is determined in the scanning path set, and the emission direction of the laser pulse signal is determined according to the target scanning path. After determining the emission direction of the laser pulse signal, the laser pulse signal is sent according to the emission direction, so that the laser pulse signal scans along the path of the target scanning path. After receiving the reflected echo optical signal of the laser pulse signal by the target object, photon counting is performed on the echo optical signal, and the arrival time of each photon is determined. The echo pulse signal is obtained according to the number of photons at each arrival time. The distance parameter of the target object is determined according to the correlation between the pulse drive signal and the echo pulse signal and the emission direction. The lidar system traverses all the scanning paths in the scanning path set S(k) to traverse the multiple emission directions of the scanning path set S(k), so that the lidar emits laser pulse signals with different emission directions, realizes the overall scanning of the target area, obtains multiple distance parameters of the target object, and integrates the distance parameters of the target object under all scanning paths to obtain the motion trajectory of the target object.

[0073] When detecting a target object, the lidar detection method of this embodiment traverses the scanning path set S(k) of the target area, and according to the detection of each scanning path, it can realize path tracking of the target object and obtain the motion trajectory of the target object.

[0074] In some specific embodiments, obtaining a pulse drive signal includes: a signal generator generates an original pulse sequence, the original pulse sequence includes a plurality of original pulses, the time interval between adjacent original pulses is randomly set, and the minimum value of the time interval between adjacent original pulses is greater than the recovery time of the photon detector; the signal generator generates a pulse drive signal according to the original pulse sequence and transmits the pulse drive signal to the laser generator, and the time interval between adjacent pulse signals in the pulse drive signal is the same as the time interval between adjacent original pulses in the original pulse sequence.

[0075] The original pulse sequence can be expressed as C0(t), which is a pulse signal generated by the transmission signal encoding module. The original pulse sequence is used to generate a pulse drive signal C s (t) in the signal generator. As described above, the time interval between adjacent pulse signals in the pulse drive signal C s (t) is randomly set. In order to generate this pulse drive signal, in this embodiment, the transmission signal module encodes according to the time interval to obtain an original pulse sequence with a randomly set time interval, so as to generate a pulse drive signal C s (t) that is the same as the original pulse signal according to the original pulse sequence.

[0076] In the original pulse sequence C0(t) generated in this embodiment, the time interval between adjacent original pulses is related to the recovery time t d of the photon detector in the lidar detection system. The recovery time t d is the time when the photon detector can effectively detect photons again after photon detection. The minimum value of the time interval between adjacent original pulses is greater than the recovery time of the photon detector.

[0077] Exemplarily, encoding according to the time interval to obtain an original pulse sequence C0(t) with a randomly set time interval, the time interval between adjacent original pulses in the original pulse sequence C0(t) can be a random number between (t d , 2t d ). According to the encoded original pulse sequence C0(t), a pulse drive signal C s (t) that is the same as the original pulse sequence C0(t) is obtained in the signal generator, so as to drive the laser generator according to the pulse drive signal C0(t) to obtain a laser pulse signal.

[0078] In some other implementation manners, the time interval between adjacent original pulses can also be a random number determined according to other methods. For example, setting it as a random number between (t d , T p / n) can also achieve the purpose of improving the detection efficiency, where T p represents the maximum distance L for target object tracking maxThe duration of the corresponding echo pulse signal, and n represents the total number of pulses in the original pulse sequence. It can be understood that the setting method of the time interval in this embodiment is not limited, as long as it can improve the detection and tracking efficiency of the lidar system.

[0079] In some other specific embodiments, obtaining the echo pulse signal according to the number of photons at each arrival time includes: the photon number resolving detector resolves the number of photons at each arrival time, and determines the echo electrical pulse corresponding to the current arrival time according to the number of photons at each arrival time, and obtains the echo pulse signal according to the echo electrical pulses corresponding to all arrival times.

[0080] The echo electrical pulse refers to the electrical pulse generated by the echo light signal reflected by the target object, and is used to represent the intensity or photon number information of the echo light signal.

[0081] In this embodiment, when processing the echo light signal to obtain the echo pulse signal, the photon number resolving detector resolves the number of photons and the photon arrival time for each photon incidence event in the echo light signal. The time for photon number resolving detection can be expressed as T p =2L max / c, where L max represents the maximum tracking distance of the target object, and c represents the speed of light. For example, T p is the duration of the echo pulse signal corresponding to the maximum distance L max for tracking the target object. At the same time, in order to avoid range ambiguity, the minimum value T p of T p_min needs to satisfy T p_min > 2nt d .

[0082] The photon number resolving detector resolves the number of photons in the echo light signal during the detection time and determines the arrival time of each photon incidence. Each incident photon will generate an echo electrical pulse, and the echo electrical pulse at this arrival time can be determined according to the number of photons at each arrival time, so as to accumulate the echo electrical pulses at multiple arrival times to obtain the echo pulse signal.

[0083] Exemplarily, the photon detector in this embodiment is a photon number resolving detector. Different from the traditional photon detector that can only be used to determine whether there are photons in the echo light signal, the photon number resolving detector in this embodiment can not only detect whether there are photons in the echo light signal, but also detect and resolve the number of photons in the echo light signal, and obtain the echo pulse signal according to each photon incidence event, improving the detection rate of the lidar detection system and the tracking efficiency of the target object.

[0084] It can be understood that the implementation form of the photon number resolving detector in this embodiment is not limited, as long as the photon number in the echo can be resolved during echo detection.

[0085] In some other embodiments, the processor determines the distance parameter of the target object according to the correlation between the pulse drive signal and the echo pulse signal, including: the processor performs cross-correlation processing on the pulse drive signal and the echo pulse signal to obtain a cross-correlation signal for characterizing the correlation result; the processor determines the distance parameter of the target object according to the cross-correlation signal.

[0086] Pulse drive signal C s (t) is a drive signal for generating a laser pulse signal, and the laser pulse signal has the same signal value as the pulse drive signal C s (t). When performing signal processing, the signal processing of the laser pulse signal can be represented by the processing and analysis of the pulse drive signal C s (t). The echo pulse signal is a pulse signal after photon number resolving detection of the echo optical signal. By collecting and converting the echo pulse signal, the echo pulse signal is converted into an echo signal W(t) that is convenient for signal processing.

[0087] Performing cross-correlation processing on the pulse drive signal C s (t) and the echo signal W(t), the correlation between the received echo signal W(t) and the transmitted laser pulse signal can be obtained according to the correlation result of the two signals, so as to determine the distance parameter of the target object according to the correlation result.

[0088] In some specific embodiments, the processor determines the distance parameter of the target object according to the cross-correlation signal, including: the processor counts the maximum peak and the second maximum peak in the cross-correlation signal. When the maximum peak is unique, the processor determines whether the ratio between the maximum peak and the second maximum peak is greater than a preset value. If so, the processor obtains the target time corresponding to the maximum peak, and determines the distance parameter of the target object according to the target time.

[0089] First, perform cross-correlation operation on the pulse drive signal C s (t) and the echo signal W(t) to obtain a cross-correlation signal representing the correlation result, and this cross-correlation signal can be expressed as Cor(t). Cor(t)=W(t) C s (t). By judging the cross-correlation signal Cor(t), the distance parameter of the target object is determined.

[0090] The maximum peak is the function value of the largest correlation peak in the cross-correlation signal, denoted as P1; the second maximum peak represents the function value of the second largest correlation peak in the cross-correlation signal, denoted as P2. In the cross-correlation signal, the correlation peak represents the pulse drive signal Cs (t) and the echo signal W(t) have a correlation point, that is, the time point when the two signals are similar.

[0091] In a lidar detection system, the pulse drive signal C s (t) represents the transmitted signal, and the echo signal W(t) represents the received signal. The cross-correlation operation is performed on the transmitted signal and the received signal. The point corresponding to the maximum peak P1 represents the time point when the transmitted signal and the received signal are most similar. The time delay at this point is the time difference between the two signals, and this time difference can be used to estimate the distance parameter of the target object.

[0092] When judging the cross-correlation signal Cor(t), first judge whether the maximum peak P1 of Cor(t) is unique, that is, whether there is only one maximum correlation peak in the correlation result Cor(t). When there is only one maximum correlation peak in the cross-correlation signal Cor(t), that is, when the maximum peak P1 is unique, judge whether the ratio between the maximum peak P1 of the maximum correlation peak and the second maximum peak P2 of the second maximum correlation peak is greater than a preset value. Exemplarily, the preset value can be 1.5.

[0093] If the ratio between the maximum peak P1 of the maximum correlation peak and the second maximum peak P2 of the second maximum correlation peak is greater than the preset value, it means that the two signals for which the cross-correlation operation is performed are significantly matched, and the reflected signal of the target object is received at the target time corresponding to the maximum peak. The target distance of the target object can be calculated through the target time. For example, the target distance d of the target object can be expressed as d = cT / 2, where c is the speed of light, and T is the time difference (t1 - t0) between the target time t1 corresponding to the maximum peak P1 and the zero time t0 of the pulse drive signal C s (t), that is, T = t1 - t0.

[0094] Based on the calculated target distance d, and according to the outgoing direction to determine the azimuth angle θ and elevation angle β corresponding to the current outgoing direction, take (d, θ, β) as the distance parameter of the target object currently scanned. According to the distance parameters obtained from multiple scans, a trajectory data set representing the movement trajectory of the target object is obtained. According to the distance parameters recorded in the trajectory data set, the possible position (θ', β') of the target object after the next T p +T fsm can be fitted by means of trajectory fitting, where T p is the duration of the echo pulse signal corresponding to the maximum tracking distance L of the aforementioned target object tracking max of the target object, and T fsmIt represents the average time taken for the fast-steering mirror to switch the outgoing direction. Update the scanning path set S(k) of the lidar detection system according to the new position (θ’, β’), and then perform the next scanning measurement based on the updated scanning path set S(k), ultimately achieving fast and high-speed detection and tracking of the target object.

[0095] In some other embodiments, the method further includes: if the cross-correlation signal includes multiple maximum peaks, or the ratio between the maximum peak and the second-largest peak is less than a preset value, then return to the step of obtaining the pulse drive signal, and the laser generator performs detection again.

[0096] Optionally, if the cross-correlation signal Cor(t) includes multiple maximum peaks, or the ratio between the maximum peak and the second-largest peak is less than a preset value, it indicates that the similarity between the pulse drive signal C s (t) and the echo signal W(t) is not high, then re-determine the outgoing direction of the laser pulse signal for target detection.

[0097] In some detailed embodiments, as Figure 2 shown, a lidar detection method is provided. Through this lidar detection method, fast and efficient detection and tracking of the target object can be achieved. The method includes the following steps 202 to step 210. Among them,

[0098] Step 202, within a detection period, the signal generator generates an original pulse sequence. The original pulse sequence includes multiple original pulses, and the time interval between adjacent original pulses is randomly set, and the minimum value of the time interval between adjacent original pulses is greater than the recovery time of the photon detector.

[0099] The generated original pulse sequence is denoted as C0(t). The original pulse sequence C0(t) includes at least three original pulses, and the time interval between adjacent original pulses takes a random number between (t d , 2t d ). t d represents the recovery time when the photon detector can effectively detect photons again after photon detection. In the lidar detection system, the original pulse sequence C0(t) can be obtained through the encoding of the transmission signal encoder.

[0100] It can be understood that the time interval between adjacent original pulses can also be a random number determined by other methods. For example, it can be a random number between (t d , T p / n). T p represents the duration of the echo pulse signal corresponding to the maximum distance L max for target object tracking, and n represents the total number of pulses in the original pulse sequence.

[0101] Step 204: The signal generator generates a pulse drive signal according to the original pulse sequence and transmits the pulse drive signal to the laser generator. The time interval between adjacent pulse signals in the pulse drive signal is the same as the time interval between adjacent original pulses in the original pulse sequence.

[0102] Generate a pulse drive signal C(t) that is the same as the original pulse sequence C0(t) according to the original pulse sequence C0(t). s (t). The pulse drive signal C s (t) drives the laser generator so that the laser generator generates a laser pulse signal under the drive of the pulse drive signal C s (t).

[0103] Step 206: The laser generator generates a laser pulse signal according to the pulse drive signal and sends the laser pulse signal to the transceiver common optical system; the transceiver common optical system sends the laser pulse signal to the target object and receives the echo optical signal reflected by the target object from the laser pulse signal.

[0104] The laser pulse signal is sent to the target object through the transceiver common optical system, and the optical component adjusts the emission direction of the laser pulse signal according to the scanning path set. After the laser pulse signal irradiates the target object through the transceiver common optical system, the echo optical signal is collected and received by the transceiver common optical system again.

[0105] In addition to the transceiver common optical system in the lidar detection system, there are also several optical components for transmitting the laser pulse signal. The optical components include a perforated mirror and a fast steering mirror for transmitting the laser pulse signal, and a fast steering mirror, a focusing lens, and a narrowband filter for receiving the echo optical signal. Exemplarily, the fast steering mirror sets the emission position of the laser pulse signal according to the emission direction determined by the scanning path set. The laser pulse signal irradiates the fast steering mirror through the perforated mirror, is reflected by the fast steering mirror, and then irradiates the transceiver common optical system and irradiates the target area.

[0106] For the echo optical signal after the reflection of the laser pulse signal, after being received by the transceiver common optical system, it is also reflected by the fast steering mirror, reflected by the mirror surface of the perforated mirror, and focused by the focusing lens, and finally filtered by the narrowband filter and received by the photon number resolving detector, and the photon number resolving detection is performed on the photon number resolving detector.

[0107] Step 208: The photon number resolving detector performs photon counting on the echo optical signal and determines the arrival time of each photon; resolves the photon number at each arrival time, determines the echo electrical pulse corresponding to the current arrival time according to the photon number at each arrival time, and obtains the echo pulse signal according to the echo electrical pulses corresponding to all arrival times.

[0108] The number of photons in the backscattered optical signal is counted by a photon number resolving detector, the echo electrical pulse corresponding to the arrival time is determined according to the number of photons received at the arrival time, and the echo pulse signal is obtained from the echo electrical pulse signal, so as to perform signal processing through the echo pulse signal.

[0109] The detection time of the photon number resolving detector is denoted as T p =2L max / c. At the same time, in order to avoid range ambiguity, the minimum value T p_min of the detection time needs to satisfy T p_min > 2nt d . Compared with the traditional method of only determining the echo pulse signal according to the presence or absence of photons, in this embodiment, the pulse information of the backscattered optical signal can be effectively extracted according to the number of photons, the interference of background noise on the backscattered optical signal is avoided, and the detection efficiency of the target object is improved.

[0110] Step 210, the processor performs cross-correlation processing on the pulse drive signal and the echo pulse signal to obtain a cross-correlation signal for characterizing the correlation result, and determines the distance parameter according to the cross-correlation signal.

[0111] In this embodiment, by generating laser pulses with random time intervals within one detection period, the problem that the traditional lidar system needs to accumulate data in multiple detection periods is avoided, the detection ability of the lidar is improved, and the anti-interference ability of the laser pulse signal is increased.

[0112] The following combines Figure 3 , and through an example, the signal processing of the pulse drive signal and the echo pulse signal to implement the method of scanning a target object is described. The scanning method includes the following steps:

[0113] Step 302, the processor determines the set of scanning paths for the target area.

[0114] Determine the set of scanning paths S(k) according to the historical detection data, and start laser detection and tracking according to the scanning paths in the set of scanning paths S(k).

[0115] Step 304, the processor determines the emission direction of the laser pulse signal according to the set of scanning paths.

[0116] Control the fast steering mirror in the optical component to deflect to the emission direction according to the scanning path, so that the generated laser pulse signal is reflected by the fast steering mirror to the target area.

[0117] Step 306, the transceiver common optical system emits the laser pulse signal according to the emission direction and receives the backscattered optical signal after the emission of the laser pulse signal.

[0118] The generated laser pulse signal is a laser pulse signal with randomly set intervals. By resolving and detecting the number of photons in the echo optical signal, an echo pulse signal is obtained. The echo pulse signal is collected to obtain an echo signal W(t) that is convenient for signal processing.

[0119] Step 308, the processor performs a cross-correlation operation on the pulse drive signal and the echo signal W(t) to obtain a cross-correlation signal; when the maximum peak in the cross-correlation signal is unique, it is determined whether the ratio between the maximum peak and the second-largest peak is greater than a preset value.

[0120] If the cross-correlation signal includes multiple maximum peaks, or the ratio between the maximum peak and the second-largest peak is less than the preset value, a new scanning path and an outgoing direction are re-determined in the scanning path set, and a laser pulse signal is sent and an echo optical signal is received according to the new outgoing direction. If all the scanning paths in the scanning path set at this time have been traversed, a new scanning path set is generated for scanning according to the new scanning path set.

[0121] Step 310, if the ratio between the maximum peak and the second-largest peak in the cross-correlation signal is greater than the preset value, the processor determines the target distance of the target object according to the target time corresponding to the maximum peak, determines the pitch angle and azimuth angle of the current scan according to the outgoing direction; determines the target motion trajectory of the target object according to the target distance, pitch angle and azimuth angle.

[0122] According to the time difference (t1 - t0) between the target time t1 corresponding to the maximum peak P1 and the zero time t0 of the pulse drive signal C s a time T is obtained, and the target distance d of the target object is expressed as d = cT / 2, where c is the speed of light. The distance parameters (d, θ, β) of the target object are obtained from the target distance d and the azimuth angle θ and pitch angle β corresponding to the current outgoing direction.

[0123] The trajectory fitting method is used to fit the possible position (θ’, β’) of the target object after the next T p + T fsm using the calculated distance parameters, where T p represents the duration of the echo pulse signal corresponding to the maximum distance L max for target object tracking, and T fsm represents the average time taken for the fast steering mirror to switch the outgoing direction. Exemplarily, the trajectory fitting can be implemented by means such as mean-shift, and the present embodiment has no limitation on this fitting method.

[0124] A new scanning path set is generated according to the generated motion trajectory (θ', β'), and then the emission direction of the next laser scan is determined according to the new scanning path set. The first scanning position in the new scanning path set is determined according to the motion trajectory (θ', β'), and then the scanning path in the scanning path set is determined according to equidistant spiral lines, equidistant hexagonal scanning lines, equidistant quadrilateral scanning lines, etc.

[0125] The laser radar detection performance of the present application is verified through experiments, and the target detection rate, false alarm rate, and single detection time of the laser radar detection method of the present application are compared with those of the traditional detection method. Figure 4 As shown, the laser radar detection method of the present application has a background noise photon count rate of 10 7 Under the conditions of strong background noise of 100 km per second and target distance of 100 kilometers, the target detection rate is 40% higher than that of traditional detection methods, and the false alarm rate is 40% lower than that of traditional detection methods. At the same time, the single detection time in target tracking of this application is reduced by 67%. The detection method of this application achieves more efficient target tracking while improving the detection rate and reducing the false alarm rate.

[0126] It should be understood that, although the various steps in the flowcharts involved in the above-mentioned embodiments are displayed in sequence according to the indication of the arrows, these steps are not necessarily executed in sequence according to the order indicated by the arrows. Unless there is a clear explanation in this article, the execution of these steps does not have a strict order restriction, and these steps can be executed in other orders. Moreover, at least a part of the steps in the flowcharts involved in the above-mentioned embodiments can include multiple steps or multiple stages, and these steps or stages are not necessarily executed at the same time, but can be executed at different times, and the execution order of these steps or stages is not necessarily to be carried out in sequence, but can be executed in turn or alternately with other steps or at least a part of the steps or stages in other steps.

[0127] In some embodiments, Figure 5 As shown, a laser radar detection system is provided, the system comprising:

[0128] The laser generator is used to obtain a pulse driving signal within a detection cycle and generate a laser pulse signal according to the pulse driving signal. The time interval between adjacent pulse signals in the pulse driving signal is randomly set, and the minimum time interval between adjacent pulse signals is greater than the recovery time of the photon detector.

[0129] The receiving / transmitting common optical system is used to send laser pulse signals and receive echo light signals reflected by the target object.

[0130] A photon number resolving detector is used to perform photon counting in the echo optical signal, determine the arrival time of each photon, and obtain an echo pulse signal based on the number of photons at each arrival time.

[0131] A processor is used to determine the distance parameter of the target object according to the correlation between the pulse drive signal and the echo pulse signal.

[0132] Optionally, the lidar detection system further includes a signal generator and an optical component. The signal generator includes a transmission signal encoder and a drive signal generator, and the transmission signal encoder is connected to the drive signal generator.

[0133] The transmission signal encoder is used to encode according to the time interval within a detection period to generate an original pulse sequence C0(t). The original pulse sequence C0(t) generated by the transmission signal encoder in this embodiment includes multiple original pulses with randomly designed time intervals to improve the detection efficiency of the lidar detection system.

[0134] The drive signal generator is used to generate a pulse drive signal C s (t) according to the original pulse sequence C0(t), and transmit the pulse drive signal C s (t) to the laser generator. The pulse drive signal C s (t) generated by the signal generator is the same as the original pulse sequence C0(t).

[0135] The laser generator includes a pulsed laser and a laser driver circuit, and the laser driver circuit is connected to the signal generator. The laser driver circuit is driven by the pulse drive signal C s (t), so that the pulsed laser generates a laser pulse signal under the drive of the laser driver circuit.

[0136] The optical component includes a perforated mirror, a fast steering mirror, a focusing lens, and a narrowband filter. Among them, the perforated mirror is a mirror with a through hole. The mirror is located in the laser emission direction of the laser generator and is placed at an angle of 45 degrees with the optical axis of the laser pulse signal emission. The laser pulse signal is transmitted outward through the through hole of the perforated mirror. Among them:

[0137] The fast steering mirror can quickly rotate in the pitch and horizontal directions, control the emission direction of the laser pulse signal through the principle of plane reflection, and receive the echo optical signal from the scanning emission direction.

[0138] The focusing lens is used to focus the echo optical signal reflected by the fast steering mirror onto the photosensitive surface of the photon number resolving detector.

[0139] The narrowband filter is a narrowband filter with high transmittance and deep cut-off depth. The central wavelength of the narrowband filter matches the central wavelength of the pulsed laser, and is used to efficiently filter out background noise outside the wavelength corresponding to the laser pulse signal.

[0140] The transceiver shared optical system adopts an inverted telescope structure, which can achieve beam expansion during the emission of laser pulse signals and beam contraction during the reception of backscattered light signals.

[0141] The photon number resolving detector has the ability to respond to weak signals at the single photon level, photon number resolving ability, and photon arrival time resolving ability, and is used to convert incident photons in the backscattered light signal into echo pulse signals.

[0142] The processor includes a signal acquisition module, a signal processing module, and a control module. Among them:

[0143] The signal acquisition module includes a signal amplification circuit, a high-speed analog-to-digital converter, a signal memory, etc. The signal acquisition module is used to perform signal processing and acquisition on the backscattered light signal of the photon number resolving detector to obtain an echo signal W(t) convenient for signal processing.

[0144] The signal processing module includes a distance calculation unit and a trajectory calculation unit. The distance calculation unit performs cross-correlation operation on the received echo signal W(t) and the pulse drive signal C s (t) of the signal generator, and judges whether there is a target object in the current scanning area by analyzing the correlation result, and calculates the target distance of the target object when there is a target object.

[0145] The trajectory calculation unit combines the calculated target distance, the azimuth angle θ and the elevation angle β determined according to the outgoing direction to obtain a distance parameter (d, θ, β) representing the target object. According to the distance parameters (d, θ, β) obtained from multiple scans, a trajectory data set representing the movement trajectory of the target object is obtained. According to the distance parameters recorded in the trajectory data set, the possible position of the target object can also be fitted by means of trajectory fitting to realize the detection and tracking of the target object.

[0146] The control module is connected to the signal processing module, generates a scanning path set according to the target trajectory set calculated by the signal processing module, and then controls the fast steering mirror according to the scanning path set in the scanning path set to determine the outgoing direction of the laser pulse signal.

[0147] In some embodiments, before the transceiver shared optical system transmits a laser pulse signal, the processor is further configured to determine a target area to be scanned and determine a set of scanning paths corresponding to the target area; the processor traverses the set of scanning paths to determine multiple emission directions of the laser pulse signal;

[0148] The transceiver shared optical system is further configured to transmit multiple laser pulse signals in accordance with the multiple emission directions, wherein the multiple laser pulse signals are used to obtain multiple echo pulse signals, and the multiple emission directions, the multiple laser pulse signals, and the multiple echo pulse signals are in one-to-one correspondence;

[0149] The processor is further configured to determine multiple distance parameters of the target object according to the correlation between the pulse drive signal and the multiple echo pulse signals, and the multiple distance parameters of the target object are used to determine the motion trajectory of the target object.

[0150] In some embodiments, the transmit signal encoder is further configured to generate an original pulse sequence, the original pulse sequence includes multiple original pulses, the time interval between adjacent original pulses is randomly set, and the minimum value of the time interval between adjacent original pulses is greater than the recovery time of the photon detector; the drive signal generator is further configured to generate a pulse drive signal according to the original pulse sequence and transmit the pulse drive signal to the laser generator, and the time interval between adjacent pulse signals in the pulse drive signal is the same as the time interval between adjacent original pulses in the original pulse sequence.

[0151] In some embodiments, the photon number resolving detector is further configured to resolve the number of photons at each arrival time, determine the echo electric pulse corresponding to the current arrival time according to the number of photons at each arrival time, and obtain the echo pulse signal according to the echo electric pulses corresponding to all arrival times.

[0152] In some embodiments, the processor is further configured to perform cross-correlation processing on the pulse drive signal and the echo pulse signal to obtain a cross-correlation signal for characterizing the correlation result; determine the distance parameter according to the cross-correlation signal.

[0153] In some of these embodiments, the processor is further configured to count the maximum peak and the second largest peak in the cross-correlation signal; in the case where the maximum peak is unique, determine whether the ratio between the maximum peak and the second largest peak is greater than a preset value; if so, obtain the target time corresponding to the maximum peak, determine the distance parameter of the target object according to the target time, and determine the target motion trajectory of the target object according to the distance parameter.

[0154] In some of these embodiments, the processor is further configured to, if the cross-correlation signal includes multiple maximum peaks, or the ratio between the maximum peak and the second largest peak is less than the preset value, return to the step of obtaining the pulse drive signal, and the laser generator performs detection again.

[0155] In an exemplary embodiment, a computer device is provided. The computer device may be a server, and its internal structure diagram may be as shown in Figure 6 . The computer device includes a processor, a memory, an input / output interface (Input / Output, abbreviated as I / O), and a communication interface. Among them, the processor, the memory, and the input / output interface are connected through a system bus, and the communication interface is connected to the system bus through the input / output interface. Among them, the processor of the computer device is used to provide computing and control capabilities. The memory of the computer device includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system, a computer program, and a database. The internal memory provides an environment for the operation of the operating system and the computer program in the non-volatile storage medium. The database of the computer device is used to store lidar detection data. The input / output interface of the computer device is used to exchange information between the processor and external devices. The communication interface of the computer device is used to communicate with external terminals through a network connection. When the computer program is executed by the processor, it implements a lidar detection method.

[0156] Those skilled in the art can understand that Figure 6 the structure shown in is only a block diagram of some structures related to the solution of the present application, and does not constitute a limitation on the computer device to which the solution of the present application is applied. The specific computer device may include more or fewer components than those shown in the figure, or combine some components, or have different component arrangements.

[0157] In an exemplary embodiment, a computer device is provided, including a memory and a processor. A computer program is stored in the memory, and when the processor executes the computer program, it implements the steps in the above method embodiments.

[0158] In an embodiment, a computer-readable storage medium is provided, on which a computer program is stored. When the computer program is executed by the processor, it implements the steps in the above method embodiments.

[0159] In an embodiment, a computer program product is provided, including a computer program. When the computer program is executed by the processor, it implements the steps in the above method embodiments.

[0160] Those of ordinary skill in the art can understand that all or part of the processes in the methods of the above embodiments can be completed by instructing relevant hardware through a computer program. The computer program can be stored in a non-volatile computer-readable storage medium. When the computer program is executed, it can include the processes of the embodiments of the above methods. Among them, any reference to a memory, database, or other medium used in the embodiments provided in the present application can include at least one of non-volatile and volatile memories. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetoresistive random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory can include random access memory (RAM) or external cache memory, etc. By way of illustration and not limitation, RAM can be in various forms, such as static random access memory (SRAM) or dynamic random access memory (DRAM), etc. The databases involved in the embodiments provided in the present application can include at least one of relational databases and non-relational databases. Non-relational databases can include distributed databases based on blockchain, etc., without limitation. The processors involved in the embodiments provided in the present application can be general-purpose processors, central processing units, graphics processing units, digital signal processors, programmable logic devices, data processing logics based on quantum computing, etc., without limitation.

[0161] The technical features of the above embodiments can be combined arbitrarily. For the sake of brevity of description, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered as the scope recorded in this specification.

[0162] The above-described embodiments only represent several implementation manners of the present application. The description is relatively specific and detailed, but it should not be construed as a limitation on the patent scope of the present application. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present application, several modifications and improvements can still be made, and these all belong to the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the appended claims.

Claims

1. A laser radar detection method, characterized in that: The method comprises: The laser generator obtains a pulse drive signal within a detection cycle, and generates a laser pulse signal according to the pulse drive signal, wherein the time interval between adjacent pulse signals in the pulse drive signal is randomly set, and the minimum time interval between adjacent pulse signals is greater than the recovery time of the photon detector; The receiving / transmitting common optical system sends the laser pulse signal and receives the echo light signal of the laser pulse signal reflected by the target object; the photon number resolution detector counts the photons in the echo light signal and determines the arrival time of each photon, and obtains the echo pulse signal according to the number of photons at each arrival time; The processor determines the distance parameter of the target object according to the correlation between the pulse drive signal and the echo pulse signal.

2. The method according to claim 1, characterized in that Before the receiving / transmitting common optical system sends the laser pulse signal, the method further includes: The processor determines a target area to be scanned, and determines a set of scanning paths corresponding to the target area; The processor traverses the scanning path set to determine multiple emission directions of the laser pulse signal; The receiving / transmitting common optical system sending the laser pulse signal comprises: The receiving / transmitting common optical system sends a plurality of laser pulse signals according to the plurality of emission directions, wherein the plurality of laser pulse signals are used to obtain a plurality of echo pulse signals, and the plurality of emission directions correspond one-to-one to the plurality of laser pulse signals and the plurality of echo pulse signals; The processor determines the distance parameter of the target object according to the correlation between the pulse drive signal and the echo pulse signal, including: The processor determines a plurality of distance parameters of the target object according to the correlation between the pulse drive signal and the plurality of echo pulse signals, and the plurality of distance parameters of the target object are used to determine the motion trajectory of the target object.

3. The method according to claim 1, characterized in that The step of obtaining a pulse driving signal comprises: The signal generator generates an original pulse sequence, wherein the original pulse sequence includes a plurality of original pulses, the time intervals between adjacent original pulses are randomly set, and the minimum time interval between adjacent original pulses is greater than the recovery time of the photon detector; The signal generator generates a pulse drive signal according to the original pulse sequence, and transmits the pulse drive signal to the laser generator. The time interval between adjacent pulse signals in the pulse drive signal is the same as the time interval between adjacent original pulses in the original pulse sequence.

4. The method according to claim 1, characterized in that The step of obtaining an echo pulse signal according to the number of photons at each arrival time includes: The photon number resolution detector resolves the number of photons at each arrival time, determines the echo electrical pulse corresponding to the current arrival time according to the number of photons at each arrival time, and obtains the echo pulse signal according to the echo electrical pulses corresponding to all arrival times.

5. The method according to claim 1, characterized in that The processor determines the distance parameter of the target object according to the correlation between the pulse drive signal and the echo pulse signal, including: The processor performs cross-correlation processing on the pulse drive signal and the echo pulse signal to obtain a cross-correlation signal for characterizing the correlation result; The processor determines a distance parameter of the target object according to the cross-correlation signal.

6. The method according to claim 5, characterized in that The processor determines the distance parameter of the target object according to the cross-correlation signal, including: The processor counts the maximum peak value and the second largest peak value in the cross-correlation signal; The processor determines, when the maximum peak value is unique, whether the ratio between the maximum peak value and the second largest peak value is greater than a preset value; If so, the processor obtains the target time corresponding to the maximum peak value, and determines the distance parameter of the target object according to the target time.

7. The method according to claim 6, characterized in that The method further comprises: If the cross-correlation signal includes multiple maximum peaks, or the ratio between the maximum peak and the second largest peak is less than a preset value, the process returns to the step of obtaining a pulse drive signal, and the laser generator performs detection again.

8. A laser radar detection system, characterized in that: The system comprises: A laser generator, used to obtain a pulse drive signal within a detection cycle, and generate a laser pulse signal according to the pulse drive signal, wherein the time interval between adjacent pulse signals in the pulse drive signal is randomly set, and the minimum time interval between adjacent pulse signals is greater than the recovery time of the photon detector; A receiving / transmitting common optical system, used for transmitting the laser pulse signal and receiving an echo optical signal of the laser pulse signal reflected by a target object; A photon number resolution detector, used to count photons in the echo light signal and determine the arrival time of each photon, and obtain an echo pulse signal according to the number of photons at each arrival time; A processor is used to determine the distance parameter of the target object according to the correlation between the pulse drive signal and the echo pulse signal.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the method according to any one of claims 1 to 7 are implemented.

10. A computer program product, comprising a computer program, characterized in that When the computer program is executed by a processor, the steps of the method according to any one of claims 1 to 7 are implemented.

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