Methods, devices, and computer equipment for processing lidar echo signals

Abstract

This invention relates to the field of lidar technology, and in particular to a method, apparatus, and computer device for processing lidar echo signals. The processing method includes: acquiring the lidar echo signal; fitting the echo signal with the preset signal to obtain a fitted signal, wherein the preset signal is obtained based on multiple pre-acquired received signals; further, calculating the detection result based on the fitted signal. Based on this method, this invention can minimize the measurement error of the laser time-of-flight and improve the ranging accuracy of the lidar.

Description

Technical Field

[0001] This invention relates to the field of lidar technology, and in particular to methods, apparatus and computer equipment for processing lidar echo signals. Background Technology

[0002] LiDAR can perform non-contact, long-range detection of the surrounding environment and reconstruct the three-dimensional environment based on the detected point cloud data. It is a high-precision opto-mechatronic device with wide applications in many fields.

[0003] Ranging accuracy is a crucial performance indicator for lidar. However, through long-term research and practice with existing technologies, the inventors have found that current lidar ranging accuracy still falls short of the ideal high precision. This is partly due to the fact that the detection signal received by lidar during ranging often contains noise, and the noise cancellation effect is poor. Furthermore, when using methods similar to PTOF ranging, existing methods for calculating laser time-of-flight have certain errors. Summary of the Invention

[0004] Based on the problems and shortcomings of the existing technology, the present invention provides a method, apparatus, computer equipment and medium for processing lidar echo signals, which can improve the ranging accuracy of the radar.

[0005] This invention provides a method for processing lidar echo signals, comprising:

[0006] Acquire the echo signal from the lidar;

[0007] The preset signal is fitted to the echo signal to obtain the fitted signal, wherein the preset signal is obtained based on multiple pre-acquired received signals;

[0008] The detection result is calculated based on the fitted signal.

[0009] Preferably, the step of calculating the detection result based on the fitted signal includes:

[0010] The laser flight time of the echo signal is determined to determine the distance to the target object.

[0011] Preferably, the fitting process based on the echo signal and the fitted signal includes:

[0012] When the sum of the squares of the deviations between the echo signal and the fitted signal is minimized, the laser flight time of the echo signal and the distance to the target object are determined.

[0013] Preferably, fitting the preset signal with the echo signal includes:

[0014] The least squares method is used to fit the preset signal to the echo signal.

[0015] Preferably, the preset signal is obtained by noise cancellation and normalization of multiple pre-acquired received signals before ranging.

[0016] Preferably, the expression for the echo signal is:

[0017] y(t) = x(t) + N(t);

[0018] y(n) = x(n) + N(n);

[0019] Where y(t) is continuous, y(n) is discrete, x(t) is the real signal, the attenuation degree and the position of the pulse on the time axis are different when the intensity and distance are different, N(t) is noise signal, and n is point number;

[0020] The expression for the fitted signal is:

[0021] x'(t) = A·f(tb);

[0022] Where f(t) is the normalized signal, A is the amplitude of the signal, and b is the delay time. If the signal is emitted at t = 0, then b is the flight time of the laser.

[0023] The expression for the sum of squares of the deviations between the echo signal and the fitted signal is:

[0024] ∑[y(n)-x'(n)] 2 ;

[0025] Where x'(n) is the discrete form of x'(t), and the solution is to find ∑[y(n)-x'(n)]. 2 When the parameters A1 and b1 are taken at their minimum values, b1 is the laser flight time.

[0026] The expression for the maximum deviation between the echo signal and the fitted signal is:

[0027] max{y(n)-x'(n)}.

[0028] Preferably, after determining the laser flight time of the echo signal and the distance to the target object, the method further includes:

[0029] The echo signal is determined to be a normal signal when the sum of the squares of the deviations between the echo signal and the fitted signal is less than a preset first threshold, and / or the maximum value of the deviation between the echo signal and the fitted signal is less than a preset second threshold; otherwise, the echo signal is determined to be an abnormal signal.

[0030] Based on the same inventive concept, the present invention also provides a processing device for lidar echo signals, comprising:

[0031] The signal acquisition module is used to acquire the echo signal of the lidar;

[0032] The signal fitting module is used to fit a preset signal with the echo signal to obtain a fitted signal, wherein the preset signal is obtained based on multiple pre-acquired received signals;

[0033] The data processing module is used to calculate the detection results based on the fitted signal.

[0034] Preferably, the data processing module is further used for:

[0035] The echo signal is determined to be a normal signal when the sum of the squares of the deviations between the echo signal and the fitted signal is less than a preset first threshold, and / or the maximum value of the deviation between the echo signal and the fitted signal is less than a preset second threshold; otherwise, the echo signal is determined to be an abnormal signal.

[0036] Based on the same inventive concept, the present invention also provides a computer device, including a memory and one or more processors, wherein the memory stores computer-readable instructions, and when the computer-readable instructions are executed by the one or more processors, the one or more processors perform the steps of the above method.

[0037] Based on the same inventive concept, the present invention also provides a computer-readable storage medium, wherein when the computer-readable instructions are executed by one or more processors, the one or more processors perform the steps of the above method.

[0038] One of the above technical solutions has the following advantages and beneficial effects:

[0039] This invention provides a method, apparatus, and computer device for processing lidar echo signals. The processing method effectively eliminates noise by fitting a preset signal to the lidar echo signal, thereby obtaining a fitted signal. The preset signal is obtained based on multiple pre-acquired received signals. Furthermore, based on the fitted signal, the detection result is calculated, which can minimize the measurement error of the laser time-of-flight and improve the ranging accuracy of the lidar. Attached Figure Description

[0040] The embodiments of this invention will be described in conjunction with the accompanying drawings. The accompanying drawings are for illustrative purposes only and are intended to describe the embodiments.

[0041] Figure 1 This is a flowchart illustrating a method for processing lidar echo signals according to an embodiment of the present invention.

[0042] Figure 2 for Figure 1 A schematic diagram illustrating the effect of fitting the preset signal with the echo signal in step S200;

[0043] Figure 3 This is a flowchart illustrating a method for processing lidar echo signals according to an embodiment of the present invention.

[0044] Figure 4 This is a flowchart illustrating a method for processing lidar echo signals according to an embodiment of the present invention.

[0045] Figure 5 This is a schematic diagram of a laser radar echo signal processing device provided in one embodiment of the present invention. Detailed Implementation

[0046] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. It is to be understood that the specific embodiments described herein are only for explaining the present invention and not for limiting the present invention. Furthermore, it should be noted that, for ease of description, only the parts related to the present invention are shown in the accompanying drawings, not all structures. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0047] The terms "first," "second," etc., used in this invention are used to distinguish different objects, not to describe a specific order. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or apparatus that includes a series of steps or units is not limited to the listed steps or units, but may optionally include steps or units not listed, or may optionally include other steps or units inherent to these processes, methods, products, or apparatuses.

[0048] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of the invention. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0049] LiDAR, short for Light Detection and Ranging, is a system that integrates laser, GPS, and IMU (Inertial Measurement Unit) technologies to acquire data and generate a precise DEM (Digital Elevation Model). The combination of these three technologies allows for highly accurate positioning of the laser beam's spot on an object, with ranging accuracy down to the centimeter level. LiDAR's greatest advantages are its precision and its rapid, efficient operation. It is a sensor used to accurately obtain three-dimensional position information; its role in a machine is analogous to human eyes, determining the position, size, external shape, and even material of an object.

[0050] LiDAR has wide applications in various fields, and ranging accuracy is a crucial performance indicator for lidar. Currently, lidar primarily uses the time-of-flight method for ranging, calculating the distance to a target object by measuring the time interval between the pulse signal emitted by the transmitter and the reflected pulse signal received by the receiver. Therefore, determining the effective reflected pulse signal, noise reduction processing, and calculating the laser's time of flight all affect the ranging accuracy of lidar.

[0051] In view of this, such as Figure 1 As shown, in one embodiment, a method for processing lidar echo signals includes steps S100-S300.

[0052] Step S100: Acquire the echo signal from the lidar.

[0053] When lidar uses the time-of-flight method for ranging, it needs to obtain the propagation time of the laser beam based on the emission time and the reception time of the echo signal reflected from the target. Then, using the speed of light, the distance between the target and the lidar is calculated. In this method, the emission and reception times must be from the same laser beam; otherwise, accurate distance data cannot be obtained. Therefore, signals in the environment with similar properties to the ranging laser beam will interfere with its ranging.

[0054] In view of this, in one embodiment, echo signals with the same wavelength as the laser emission signal are identified and excluded. Specifically, interference from interfering signals can be eliminated by configuring transmission coding information and reception coding information that include transmission and reception strategy information for multiple laser signals of different wavelengths, thereby determining the valid echo signals.

[0055] When lidar operates in harsh outdoor environments, it is easily affected by interference sources such as rain, snow, and dust, which can affect the lidar's normal detection.

[0056] In view of this, in one embodiment, the time interval between the first and second emission pulses emitted sequentially towards the target direction by the lidar can be set, and the echo signals returned by the two emission pulses can be collected separately. The light intensity of the first emission pulse is less than that of the second emission pulse. If the interference source is close to the target, the echo signal of the second emission pulse is completely filtered out, and the echo signal of the first emission pulse undergoes multi-echo filtering to obtain a valid echo signal. If the interference source is far from the target, the echo signal of the first emission pulse is completely filtered out, and the echo signal of the second emission pulse undergoes multi-echo filtering to obtain a valid echo signal.

[0057] The expression for the echo signal is as follows:

[0058] y(t) = x(t) + N(t);

[0059] y(n) = x(n) + N(n).

[0060] Wherein, y(t) is continuous, y(n) is discrete, x(t) is the real signal, the attenuation degree and the position of the pulse on the time axis are different when the intensity and distance are different, N(t) is noise signal, and n is point number.

[0061] In existing technologies, when lidar measures the distance to a target, the radar signal transmitted by the transmitter may scatter during propagation. This scattered signal, after reflection, may generate cluttered echo signals, which interfere with the target's echo signal. That is, the first echo signal received by the receiver corresponding to the transmitter may include both the target's echo signal and the aforementioned cluttered echo signal, i.e., noise signal. Therefore, lidar ranging based on the echo signal received by the receiver results in lower accuracy.

[0062] Step S200: Fit the preset signal with the echo signal to obtain the fitted signal.

[0063] The preset signal is obtained based on multiple pre-acquired received signals.

[0064] In order to eliminate noise signals in the echo signal, the echo signal needs to be subjected to average signal fitting processing.

[0065] In one embodiment, fitting the preset signal to the echo signal includes: using the least squares method to fit the preset signal to the echo signal.

[0066] The preset signal is obtained by noise cancellation and normalization of multiple pre-acquired received signals. Specifically, it is the normalized signal at any given time obtained by acquiring multiple echo signals, performing noise cancellation processing, and then performing translation, normalization, and spline interpolation processing. This includes obtaining the average value of multiple received signals to achieve noise cancellation.

[0067] The expression for the fitted signal is:

[0068] x'(t) = A·f(tb);

[0069] Where f(t) is the normalized signal, A is the amplitude of the signal, and b is the delay time. If the time when the signal is emitted is t = 0, then b is the flight time of the laser.

[0070] The effect of fitting the preset signal with the echo signal is as follows: Figure 2 As shown.

[0071] Step S300: Calculate the detection result based on the fitted signal.

[0072] In one embodiment, calculating the detection result based on the fitted signal includes determining the laser flight time of the echo signal, thereby determining the distance to the target object.

[0073] Specifically, when the sum of the squares of the deviations between the echo signal and the fitted signal is minimized, the laser flight time of the echo signal and the distance to the target object are determined.

[0074] The expression for the sum of squares of the deviations between the echo signal and the fitted signal is as follows:

[0075] ∑[y(n)-x'(n)] 2 ;

[0076] Where x'(n) is the discrete form of x'(t), and the solution is to find ∑[y(n)-x'(n)]. 2 If the parameters A1 and b1 are taken at their minimum values, then b1 is the laser flight time.

[0077] The expression for the maximum deviation between the echo signal and the fitted signal is:

[0078] max{y(n)-x'(n)}.

[0079] like Figure 3 As shown, in one embodiment, step S300 is followed by step S400.

[0080] S400: Determine that the sum of squares of the deviations between the echo signal and the fitting signal is less than a preset first threshold, and / or the maximum value of the deviation between the echo signal and the fitting signal is less than a preset second threshold.

[0081] If so, execute step S410: Determine that the echo signal is a normal signal.

[0082] If not, execute step S420: Determine that the echo signal is an abnormal signal.

[0083] It can be understood that the above embodiments can also identify noise signals such as rain, snow, fog, trailing points, etc., and make a judgment by comparing the sum of squares of the differences between the received signal y(t) and the fitted signal A·f(t - b), and the maximum error between y(t) and the fitted signal A·f(t - b), that is, when ∫{y(t) - A·f(t - b)} 2 < T1 and max{y(t) - A·f(t - b)} < T2, written in discrete form as ∑{y(n) - x'(n)} 2 < T1 and max{y(n) - x'(n)} < T2, then it is determined as a normal signal, otherwise it is a noise signal.

[0084] As Figure 4 shown, in one embodiment, the steps of calculating the target distance and identifying the noise signal are as follows:

[0085] 1. Obtain several received signals in advance;

[0086] 2. Obtain the normalized signal f(t) through averaging, translation, and normalization, and store it in advance;

[0087] 3. Obtain the received signal y(n) in real time during application;

[0088] 4. Fit y(n) with x'(t) = A·f(t - b), and solve for the parameters A1 and b1 when ∑[y(n) - x'(n)]2 takes the minimum value, then b1 is the laser flight time Δt;

[0089] 5. Take the moment with the maximum function value as the return moment of light, and according to obtain the distance between the radar and the target object;

[0090] 6. Judge whether y(n) is a noise signal. When ∑{y(n) - x'(n)} 2 < T1 and max{y(n) - x'(n)} < T2, then it is judged as a normal signal, otherwise it is a noise signal.

[0091] The above describes a method to effectively eliminate noise by fitting a preset signal to the echo signal of the lidar, thereby obtaining a fitted signal. The preset signal is determined by a normalized signal at any given time. Furthermore, when the sum of the squares of the deviations between the echo signal and the fitted signal is minimized, the laser flight time of the echo signal and the distance to the target object are determined. This minimizes the measurement error of the laser flight time and improves the ranging accuracy of the lidar.

[0092] like Figure 5 As shown, based on the same inventive concept, one embodiment of the present invention also provides a processing device for lidar echo signals, comprising:

[0093] The signal acquisition module 10 is used to acquire the echo signal of the lidar.

[0094] The expression for the echo signal is as follows:

[0095] y(t) = x(t) + N(t);

[0096] y(n) = x(n) + N(n).

[0097] Wherein, y(t) is continuous, y(n) is discrete, x(t) is the real signal, the attenuation degree and the position of the pulse on the time axis are different when the intensity and distance are different, N(t) is noise signal, and n is point number.

[0098] In existing technologies, when lidar measures the distance to a target, the radar signal transmitted by the transmitter may scatter during propagation. This scattered signal, after reflection, may generate cluttered echo signals, which interfere with the target's echo signal. That is, the first echo signal received by the receiver corresponding to the transmitter may include both the target's echo signal and the aforementioned cluttered echo signal, i.e., noise signal. Therefore, lidar ranging based on the echo signal received by the receiver results in lower accuracy.

[0099] The signal fitting module 20 is used to fit the preset signal with the echo signal to obtain a fitted signal.

[0100] The preset signal is obtained based on multiple pre-acquired received signals.

[0101] To eliminate noise in the echo signal, the echo signal needs to be averaged and fitted. In one embodiment, the signal fitting module 20 is further configured to use the least squares method to fit a preset signal to the echo signal.

[0102] The preset signal is obtained by noise elimination and normalization of multiple pre-acquired received signals before ranging.

[0103] The expression for the fitted signal is:

[0104] x'(t) = A·f(tb);

[0105] Where f(t) is the normalized signal, A is the amplitude of the signal, and b is the delay time. If the signal is emitted at t = 0, then b is the flight time of the laser.

[0106] The effect of fitting the preset signal with the echo signal is as follows: Figure 2 As shown.

[0107] The data processing module 30 is used to calculate the detection result based on the fitted signal.

[0108] In one embodiment, the data processing module 30 is used to determine the laser flight time of the echo signal, thereby determining the distance to the target object. Specifically, it is used to determine the laser flight time of the echo signal and the distance to the target object when the sum of the squares of the deviations between the echo signal and the fitted signal is minimized.

[0109] The expression for the sum of squares of the deviations between the echo signal and the fitted signal is as follows:

[0110] ∑[y(n)-x'(n)] 2 ;

[0111] Where x'(n) is the discrete form of x'(t), and the solution is to find ∑[y(n)-x'(n)]. 2 If the parameters A1 and b1 are taken at their minimum values, then b1 is the laser flight time.

[0112] The expression for the maximum deviation between the echo signal and the fitted signal is:

[0113] max{y(n)-x'(n)}.

[0114] In one embodiment, the data processing module 40 is configured to determine that the echo signal is a normal signal when the sum of the squares of the deviations between the echo signal and the fitted signal is less than a preset first threshold, and / or when the maximum value of the deviation between the echo signal and the fitted signal is less than a preset second threshold; otherwise, to determine that the echo signal is an abnormal signal.

[0115] It can be understood that the above embodiments can also identify noise signals such as rain, snow, fog, trailing points, etc. The judgment is made by comparing the sum of squares of the differences between the received signal y(t) and the fitted signal A·f(t - b), and the maximum error between y(t) and the fitted signal A·f(t - b). That is, when ∫{y(t) - A·f(t - b)} 2 <T1 and max{y(t) - A·f(t - b)} < T2, written in discrete form as ∑{y(n) - x'(n)} 2 <T1 and max{y(n) - x'(n)} < T2, it is determined as a normal signal; otherwise, it is a noise signal.

[0116] As above, by fitting the preset signal with the echo signal of the lidar, the noise can be effectively eliminated to obtain the fitted signal, where the preset signal is determined by the normalized signal at any time. Further, when the sum of squares of the deviations between the echo signal and the fitted signal is minimized, the laser flight time of the echo signal and the distance of the target object are determined, which can minimize the measurement error of the laser flight time and improve the ranging accuracy of the lidar. [[ID=⑧]] [[ID=⑨]]

[0117] [[ID=⑩]]In one embodiment, the present application also provides a processing device for lidar echo signals, which can execute the above processing method for lidar echo signals. [[ID=⑪]] [[ID=⑫]]

[0118] [[ID=⑬]]Based on this, the processing device for lidar echo signals includes: a laser generation module, a laser emission module, a laser reception module, a signal processing module, and a distance calculation module; the laser generation module is respectively connected to the laser emission module and the distance calculation module, and the signal processing module is respectively connected to the laser reception module and the distance calculation module; the laser generation module is used to generate multiple laser emission signals with different wavelengths according to the emission coding information and send the emission coding information to the distance calculation module; the laser emission module is used to collimate and emit the multiple laser emission signals with different wavelengths; the laser reception module is used to receive the laser echo signal returned by the measured object and converge the laser echo signal; the signal processing module is used to identify multiple laser echo signals with the same wavelength as the laser emission signal in the converged laser echo signal, generate reception coding information, and send the reception coding information to the distance calculation module; the distance calculation module is used to calculate the distance value of the measured object according to the emission coding information and the reception coding information. Since the emission coding information and the reception coding information include the emission and reception strategy information of multiple laser signals with different wavelengths, as the environmental complexity and the number of lidars used increase, the interference of interference signals can be excluded by matching the laser emission signal and the laser echo signal in the emission coding information and the reception coding information, and the distance value of the measured object can be calculated through multiple effective laser emission signals and laser echo signals that are matched, effectively improving the ranging accuracy.

[0119] Based on the same inventive concept, one embodiment of the present invention also provides a computer device, including a memory and one or more processors, wherein the memory stores computer-readable instructions, and when the computer-readable instructions are executed by the one or more processors, the one or more processors perform the steps of the above-described method.

[0120] Based on the same inventive concept, one embodiment of the present invention also provides a computer-readable storage medium, wherein when the computer-readable instructions are executed by one or more processors, the one or more processors perform the steps of the above method.

[0121] It should be understood that, in various embodiments of the present invention, the order of the above-mentioned process numbers does not imply the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present invention.

[0122] Those skilled in the art will recognize that the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementations should not be considered beyond the scope of this invention.

[0123] Those skilled in the art will understand that, for the sake of convenience and brevity, the specific working processes of the systems, devices, and units described above can be referred to the corresponding processes in the foregoing method embodiments, and will not be repeated here.

[0124] In the embodiments provided by this invention, it should be understood that the disclosed systems, apparatuses, and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative; for instance, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be through some interfaces; the indirect coupling or communication connection between devices or units may be electrical, mechanical, or other forms.

[0125] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0126] In addition, the functional units in the various embodiments of the present invention can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit.

[0127] If the aforementioned functions are implemented as software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this invention, essentially, or the part that contributes to the prior art, or a portion of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of this invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0128] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A method for processing lidar echo signals, characterized in that, include: Acquire the echo signal from the lidar; The preset signal is fitted to the echo signal to obtain the fitted signal, wherein the preset signal is obtained based on multiple pre-acquired received signals; Based on the fitted signal, the detection result is calculated; The calculation of the detection result based on the fitted signal includes: When the sum of the squares of the deviations between the echo signal and the fitted signal is minimized, the laser flight time of the echo signal and the distance to the target object are determined.

2. The method for processing lidar echo signals according to claim 1, characterized in that, The step of fitting the preset signal with the echo signal includes: The least squares method is used to fit the preset signal to the echo signal.

3. The method for processing lidar echo signals according to claim 1, characterized in that, The preset signal is obtained by noise elimination and normalization of multiple pre-acquired received signals before ranging.

4. The method for processing lidar echo signals according to claim 1, characterized in that, The expression for the echo signal is: ； ； in It is in continuous form. It is in discrete form. This is a real signal, and the attenuation degree and the position of the pulse on the time axis vary depending on the intensity and distance of the real signal. The signal is noise, and n is the point number. The expression for the fitted signal is: ； in, For normalized signals, Let b be the amplitude of the signal and t be the delay time. If the signal is emitted at t=0, then b is the flight time of the laser. The expression for the sum of squares of the deviations between the echo signal and the fitted signal is: ； in, for The discrete form of the solution makes Parameters when taking the minimum value , ,but This is the laser flight time; The expression for the maximum deviation between the echo signal and the fitted signal is: 。 5. The method for processing lidar echo signals according to claim 4, characterized in that, After determining the laser flight time of the echo signal and the distance to the target object, the method further includes: The echo signal is determined to be a normal signal when the sum of the squares of the deviations between the echo signal and the fitted signal is less than a preset first threshold, and / or the maximum value of the deviation between the echo signal and the fitted signal is less than a preset second threshold; otherwise, the echo signal is determined to be an abnormal signal.

6. A processing device for lidar echo signals, characterized in that, include: The signal acquisition module is used to acquire the echo signal of the lidar; The signal fitting module is used to fit a preset signal with the echo signal to obtain a fitted signal, wherein the preset signal is obtained based on a plurality of pre-acquired received signals; The data processing module is used to calculate the detection results based on the fitted signal; The data processing module is specifically used for: When the sum of the squares of the deviations between the echo signal and the fitted signal is minimized, the laser flight time of the echo signal and the distance to the target object are determined.

7. The laser radar echo signal processing apparatus according to claim 6, characterized in that, The data processing module is also used for: The echo signal is determined to be a normal signal when the sum of the squares of the deviations between the echo signal and the fitted signal is less than a preset first threshold, and / or the maximum value of the deviation between the echo signal and the fitted signal is less than a preset second threshold; otherwise, the echo signal is determined to be an abnormal signal.

8. A computer device comprising a memory and one or more processors, the memory storing computer-readable instructions which, when executed by the one or more processors, cause the one or more processors to perform the steps of the method according to any one of claims 1-5.

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