Laser radar echo signal processing method, readable storage medium and laser radar

Abstract

The embodiment of the invention provides a laser radar echo signal processing method, a readable storage medium and a laser radar, and the processing method comprises the steps: transmitting a laser signal to a to-be-detected article, and receiving an initial echo signal fed back by the to-be-detected article; dividing the initial echo signal into multiple paths of first echo signals with different sizes; sequentially detecting whether the multiple paths of first echo signals meet a preset echo signal judgment condition or not; and if a target first echo signal meeting a preset echo signal judgment condition exists in the multiple paths of first echo signals, taking the target first echo signal as a target echo signal to be received by the laser radar. The object signal is effectively prevented from being shielded by the interference signal, the identification accuracy of the object signal is improved, and the signal-to-noise ratio is effectively improved. Besides, through the N optical receiving units with different sensitivities, the laser radar can receive echo signals with higher power and echo signals with lower power, and the dynamic range of the laser radar is effectively improved.

Description

Technical Field

[0001] The present application relates to the technical field of lidar, and specifically relates to a lidar echo signal processing method, a lidar, a readable storage medium, and a lidar. Background Art

[0002] During the current use of lidar, the phenomenon of too low signal-to-noise ratio occasionally occurs. In addition, it is also possible that the echo signal does not match the measured distance significantly (that is, the signal reflecting the true measured distance is lost). The above phenomena seriously reduce the signal-to-noise ratio of the lidar. In addition, the existing lidar also has the problem of insufficient dynamic range, which affects the normal operation of the lidar under different lighting conditions and seriously affects the normal use of the lidar. Summary of the Invention

[0003] The purpose of the present application is to provide a lidar echo signal processing method, a readable storage medium, and a lidar, aiming to solve the problems that the echo signal does not match the measured distance significantly and the dynamic range is insufficient in the prior art.

[0004] In a first aspect, an embodiment of the present application provides a lidar echo signal processing method, and the method includes: Transmit a laser signal to a scanning area and receive an echo signal, where the echo signal carries information of the scanning area; Divide the echo signal into N sub-echo signals with different powers according to a preset ratio, where N is a positive integer not less than 2; The lidar includes N photoelectric induction units with different sensitivities. The N photoelectric induction units are connected to the N sub-echo signals in one-to-one correspondence, and the sensitivity of the photoelectric induction unit and the power of the sub-echo signal are negatively correlated; Based on the N sub-echo signals and the N photoelectric induction units, obtain N induction currents; According to a preset current judgment condition, obtain a final induction current from the N induction currents; According to the final induction current, obtain an object signal of the scanning area.

[0005] In some possible embodiments, the step of obtaining a final induction current from the N induction currents according to a preset current judgment condition includes: Respectively judge whether the N induction currents reach the saturation currents of the corresponding photoelectric induction units, and define A as the difference between the induction current and the corresponding saturation current; If the A of the N induction currents are all less than 0, obtain the final induction current from the N induction currents according to a first preset strategy; If the A component of the N-channel induced current is equal to 0, the final induced current is obtained from the N-channel induced currents according to the second preset strategy.

[0006] In some possible embodiments, obtaining the object signal of the scanning area according to the final induced current includes: Obtaining a final induced signal according to the final induced current; Obtaining an interference signal according to the final induced signal; Obtaining a final object signal according to the final induced signal and the interference signal; Defining the final object signal as the object signal of the scanning area.

[0007] In some possible embodiments, obtaining the final induced current from the N-channel induced currents according to the preset current judgment condition includes: Respectively determining whether the N-channel induced currents reach the saturation currents of the corresponding optoelectronic induction units, and defining A as the difference between the induced current and the corresponding saturation current; Defining the M-channel induced currents with A less than 0 as the final induced current, where M is a positive integer not greater than N.

[0008] In some possible embodiments, obtaining the object signal of the scanning area according to the final induced current includes: Obtaining a final induced signal according to the final induced current; Obtaining an interference signal according to the final induced signal; Obtaining a final object signal according to the final induced signal and the interference signal; Traversing to obtain the M-channel final object signals and M-channel interference signals, and obtaining the object signal of the scanning area from the M-channel final object signals according to the third preset strategy.

[0009] In some possible embodiments, the interference signal includes a first interference sub-signal; Obtaining the interference signal according to the final induced signal includes: Judging whether the first moment corresponding to the first waveform signal in the final induced signal is within the first preset time range, where the first waveform signal is the first waveform signal in the final induced signal; If the first moment is within the preset first time range, determining the first waveform signal as the first interference sub-signal.

[0010] In some possible embodiments, the interference signal further includes a second interference sub-signal; Obtaining the interference signal according to the final induced signal further includes: Determine whether the second moment corresponding to the second waveform signal in the final induction signal is within a second preset time range, where the second waveform signal is the second waveform signal located in the final induction signal; If the second moment is within the second preset time range, determine that the second waveform signal is a second interference sub-signal.

[0011] In some possible embodiments, if the interference signal satisfies a fourth preset strategy, determine that the interference signal includes an interface reflection signal, including: Obtain a corresponding interference signal point cloud based on the interference signal; Based on the interference signal point cloud, obtain an interference signal point cloud image; According to the interference signal point cloud image, determine whether there is a region parallel to the horizontal plane in the interference signal point cloud image; If there is a region parallel to the horizontal plane in the interference signal point cloud image, determine that the region parallel to the horizontal plane is an interface region and determine that the interference signal includes an interface reflection signal.

[0012] In some possible embodiments, the obtaining the final object signal according to the final induction signal and the interference signal includes: In the final induction signal, exclude the interference signal to obtain a first induction signal; Determine that the first induction signal is the final object signal.

[0013] In some possible embodiments, after excluding the interference signal in the final induction signal to obtain a first induction signal, it further includes: Determine whether the third moment corresponding to the third waveform signal in the first induction signal is within a third preset time range, where the third waveform signal is the first waveform signal in the first induction signal; If the third moment is within the third preset time range, determine that the first induction signal is the final object signal.

[0014] In some possible embodiments, the determining that the first induction signal is the final object signal further includes: Determine that the first induction signal is a suspected object signal; Determine whether the suspected object signal satisfies a fifth preset strategy; If the suspected object signal satisfies the fifth preset strategy, determine that the suspected object signal is the final object signal.

[0015] In some possible embodiments, the if the suspected object signal satisfies the fifth preset strategy, determine that the suspected object signal is the final object signal includes: Obtain the corresponding suspected object point cloud based on the suspected object signal; Based on the suspected object point cloud, obtain a suspected object point cloud image; According to the suspected object point cloud image, determine whether there is a continuous area in the suspected object point cloud image; If there is a continuous area in the suspected object point cloud image, the continuous area is the object area, and the signal corresponding to the object area is the final object signal.

[0016] In some possible embodiments, the determining that the first induction signal is the final object signal further includes: Determine the first induction signal as the initial object signal; Obtain interface point cloud data according to the interface reflection signal; Obtain object point cloud data according to the initial object signal of the scanning area; According to the refractive index between the interface area and the scanning area and the interface point cloud data, correct the object point cloud data to obtain real object point cloud data; Determine the final object signal of the scanning area according to the real object point cloud data.

[0017] In a second aspect, the present application provides a readable storage medium, which is suitable for being loaded by a processor to execute the steps in any of the above-mentioned lidar echo signal processing methods.

[0018] In a third aspect, the present application provides a lidar, which includes: A laser emission module for emitting a laser signal to a scanning area; A laser reception module, the laser reception module includes a beam splitting unit, and the beam splitting unit is used to divide the echo signal into N sub-echo signals with different powers according to a preset ratio, where N is a positive integer not less than 2; the laser reception unit further includes N photoinductive units with different sensitivities, and the N photoinductive units are connected to the N sub-echo signals in one-to-one correspondence, and the sensitivity of the photoinductive unit is negatively correlated with the power of the sub-echo signal, and the N photoinductive units are used to receive the N sub-echo signals; A judgment module, which obtains N induction currents based on the N sub-echo signals and N light reception units; obtains a final induction current from the N induction currents according to a preset current judgment condition; and obtains an object signal of the scanning area according to the final induction current.

[0019] In some possible embodiments, the lidar further includes a memory and a processor, and the processor is configured to call a computer program stored in the memory to execute the steps in the lidar echo signal processing method described above.

[0020] In some possible embodiments, the lidar further includes a readable storage medium, which is suitable for being loaded by the processor to execute the steps in the lidar echo signal processing method.

[0021] The embodiments of the present application provide a lidar echo signal processing method, a readable storage medium, and a lidar. By splitting the echo signal carrying the scanning area information, N sub-echo signals with different powers are obtained, and N optical receiving units with different sensitivities are used to respectively sense the N sub-echo signals to obtain N induced currents, and the optimal induced current in the non-saturated state is determined, thereby preventing the target signal from being shielded by the interference signal, improving the accuracy of identifying the target signal, and effectively improving the signal-to-noise ratio. In addition, by using N optical receiving units with different sensitivities, the lidar can receive echo signals with larger powers and echo signals with smaller powers, which also effectively improves the dynamic range of the lidar. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The following, by describing the specific embodiments of the present application in detail in conjunction with the drawings, will make the technical solutions and other beneficial effects of the present application obvious.

[0023] Figure 1 It is a schematic flowchart of Embodiment 1; Figure 2 It is a schematic flowchart of step S5 in Embodiment 2; Figure 3 It is a schematic flowchart of step S6 in Embodiment 2; Figure 4 It is a schematic flowchart of step S5 in Embodiment 3; Figure 5 It is a schematic flowchart of step S6 in Embodiment 3; Figure 6 It is a schematic flowchart of Embodiment 4; Figure 7 It is a schematic flowchart of step 3 in Embodiment 5; Figure 8 It is a schematic flowchart of step 3.3 in Embodiment 5; Figure 9 It is another schematic flowchart of step 3 in Embodiment 5; Figure 10 It is a schematic diagram of the principle of reflection and refraction in Embodiment 5; Figure 11 It is a schematic flowchart of step 3.4' in Embodiment 5; Figure 12 It is a schematic flow diagram of step 3.4'.1 in Example 5; Specific implementation manner

[0024] The present application will be further described in detail below in conjunction with the accompanying drawings and examples. It should be specifically noted that the following examples are only used to illustrate the present application, but do not limit the scope of the present application. Similarly, the following examples are only partial examples of the present application rather than all examples. All other examples obtained by those of ordinary skill in the art without creative efforts belong to the scope protected by the present application.

[0025] In the following description of the present application, the terms "first / second / third" only distinguish similar objects and do not represent a specific order for the objects. It can be understood that "first / second / third" can be interchanged with a specific order or sequence when allowed, so that the embodiments of the present application described herein can be implemented in an order other than that illustrated or described herein.

[0026] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the technical field to which the present application belongs. The terms used herein are only for the purpose of describing the embodiments of the present application and are not intended to limit the present application.

[0027] For ease of understanding, the background art will now be explained in detail.

[0028] The lidar emits detection signals (laser beams) towards the scanning area, and then receives the signals (echo signals) reflected from the targets in the scanning area. Relevant information about the scanning area can be obtained by analyzing the echo signals. However, during the actual scanning process, there may still be interference signals in the echo signals received by the lidar, and sometimes the intensity of these interference signals is very high. However, existing lidars only have a photoelectric induction unit with a fixed sensitivity, and the relatively strong interference signals may cause the photoelectric induction unit to enter the saturation state. Since the induced current output by the photoelectric induction unit in the saturation state will produce a pulse "broadening" phenomenon, that is, the pulse width of the electrical signal corresponding to the interference signal will "broaden", thus shielding the target signal and causing the target signal to be unrecognizable. The above phenomenon not only leads to the loss of the target signal, but also causes a significant reduction in the signal-to-noise ratio of the entire lidar on the receiving side. In addition, in the actual process, due to the different reflectivities of different targets in the scanning area, high-reflectivity targets (such as mirrors, etc.) will result in a higher intensity of the target signal, and low-reflectivity targets (such as cement walls, etc.) will result in a lower intensity of the target signal. Also, targets at different distances in the scanning area will also cause changes in the intensity of the target signal. Targets at a farther distance will result in a lower intensity of the target signal, and targets at a closer distance will result in a higher intensity of the target signal. The above various factors will cause a large difference in the signal intensity between different targets in the scanning area. The ratio between the minimum intensity and the maximum intensity of the target signal that can be effectively detected and measured is defined as the dynamic range of the lidar. The dynamic range of the lidar reflects the adaptability of the lidar in different scanning area environments. However, existing lidars only have a photoelectric induction unit with a fixed sensitivity, resulting in a large constraint on the dynamic range of the lidar, which restricts the use of the lidar.

[0029] The following will be described in detail with specific embodiments. It should be noted that the serial numbers of the following embodiments do not limit the preferred order of the embodiments.

[0030] Embodiment 1

[0031] This Embodiment 1 provides a method for processing lidar echo signals, as Figure 1 shown, which may include the following steps: S1: Transmit a laser signal towards the scanning area and receive the echo signal, and the echo signal carries information about the scanning area; S2: Divide the echo signal into N sub-echo signals with different powers according to a preset ratio, where N is a positive integer not less than 2; Specifically, a spectroscope (a spectroscope is an optical component used to split incident light into two or more different light beams at a specified ratio) can be used to divide the echo signal into several sub-echo signals with different powers. For example, the echo signal can be divided into two sub-echo signals according to a ratio of 3:7. The power of one sub-echo signal is 30% of the power of the echo signal, and the power of the other sub-echo signal is 70% of the power of the echo signal. It should be noted that the above example is only for illustration and does not constitute a limitation to this application. The power division ratio different from the above example can be set according to actual needs, the number of sub-echo signals more than two can be set according to actual needs, and other optical components can also be used to achieve beam splitting according to a preset ratio as required.

[0032] S3: The lidar includes N types of photoinductive units with different sensitivities. The N types of photoinductive units are connected to N sub-echo signals one by one, and the sensitivity of the photoinductive unit is negatively correlated with the power of the sub-echo signal. Specifically, the number of types of photoinductive units with different sensitivities (sensitivity refers to the response degree of the photoinductive unit to the change of light intensity, specifically manifested as how much the electrical signal changes caused by the change of unit light intensity within a certain illumination range) corresponding to the number of sub-echo signals needs to be set, and the matching is performed according to the negative correlation between the sensitivity of the photoinductive unit and the power of the sub-echo signal, that is, the sub-echo signal with the maximum power is matched with the photoinductive unit with the lowest sensitivity, the sub-echo signal with the second highest power is matched with the photoinductive unit with the second lowest sensitivity, until the sub-echo signal with the minimum power is matched with the photoinductive unit with the highest sensitivity. For example, there are 3 sub-echo signals, arranged in descending order of power as A1, A2, and A3; there are 3 photoinductive units, arranged in descending order of power as B1, B2, and B3. At this time, the corresponding relationship is A1 is matched with B3, A2 is matched with B2, and A3 is matched with B1.

[0033] Through the negative correlation matching mechanism between the sensitivity of the photoelectric induction unit and the power of the sub-echo signal, the photoelectric induction unit is maximally prevented from entering the saturation state (after the photoelectric induction unit enters the saturation state, the change of the photoelectric induction current cannot accurately reflect the change of the optical signal intensity), and at the same time, it is ensured that a relatively high photoelectric induction current can be excited by a sub-echo signal with a small power. The above settings have the same effect on the interference signal and the target signal in the sub-echo signal. Since the photoelectric induction unit is maximally prevented from entering the saturation state, the induction current corresponding to the interference signal will not be "broadened" in pulses based on the saturation state of the photoelectric induction unit, thereby preventing the target signal from being shielded by the interference signal and improving the accuracy of identifying the target signal, effectively improving the signal-to-noise ratio. In addition, the above settings enable the lidar to receive echo signals with greater power on the one hand (based on the low-sensitivity photoelectric induction unit to avoid entering the saturation state), and to receive echo signals with smaller power on the other hand (based on the high-sensitivity photoelectric induction unit to generate a relatively high photoelectric induction current), thereby effectively improving the dynamic range of the lidar.

[0034] S4: Based on N sub-echo signals and N types of photoelectric induction units, obtain N induction currents; S5: According to the preset current judgment condition, obtain the final induction current among the N induction currents; Specifically, due to the negative correlation matching mechanism between the sensitivity of the photoelectric induction unit and the power of the sub-echo signal, N sub-echo signals generate N induction currents. At this time, it is also necessary to screen the N induction currents. First, the induction currents that have entered the saturation state need to be excluded. Secondly, among the remaining induction currents in the normal working state, the induction current with the largest current value is selected as the final induction current.

[0035] S6: According to the final induction current, obtain the target signal in the scanning area.

[0036] In this embodiment, the echo signal carrying the scanning area information is split to obtain N sub-echo signals with different powers, and based on the negative correlation matching mechanism between the sensitivity of the photoelectric induction unit and the power of the sub-echo signal, different sensitivity optical receiving units are used to respectively sense the N sub-echo signals to obtain N induction currents, and the best induction current in the non-saturated state is determined, thereby preventing the target signal from being shielded by the interference signal, improving the accuracy of identifying the target signal, and effectively improving the signal-to-noise ratio. In addition, by using N types of optical receiving units with different sensitivities, the lidar can receive echo signals with greater power and echo signals with smaller power, which also effectively improves the dynamic range of the lidar.

[0037] Embodiment 2

[0038] Embodiment 2 expands the technical solution provided in Embodiment 1 from the perspective of specific applications, mainly explaining how to determine the final object signal among N-channel induced currents. Regarding the definitions of nouns in Embodiment 2, reference can be made to Embodiment 1 if there is no special indication. For relevant information such as the detailed content, technical effects, and technical problems solved in each step of Embodiment 2, reference can be made to Embodiment 1 if there is no special indication. Without violating the design purpose and physical laws, some optional or preferred options in Embodiment 1 are applicable to Embodiment 2.

[0039] This embodiment provides a method for processing lidar echo signals, which may include the following steps: S1: Transmit a laser signal to the scanning area and receive the echo signal, where the echo signal carries information about the scanning area; S2: Divide the echo signal into N sub-echo signals with different powers according to a preset ratio, where N is a positive integer not less than 2; S3: The lidar includes N types of optoelectronic induction units with different sensitivities. The N types of optoelectronic induction units are connected to the N sub-echo signals one by one, and the sensitivity of the optoelectronic induction unit is negatively correlated with the power of the sub-echo signal; S4: Based on the N sub-echo signals and the N types of optoelectronic induction units, obtain N-channel induced currents; S5: According to the preset current judgment condition, obtain the final induced current among the N-channel induced currents; In a possible implementation manner, as Figure 2 shown, obtaining the final induced current among the N-channel induced currents according to the preset current judgment condition includes: S51: Respectively judge whether the N-channel induced currents reach the saturation currents of the corresponding optoelectronic induction units, and define A as the difference between the induced current and the corresponding saturation current; S52: If the A values of the N-channel induced currents are all less than 0, obtain the final induced current according to the first preset strategy among the N-channel induced currents; S53: If some of the A values of the N-channel induced currents are equal to 0, obtain the final induced current according to the second preset strategy among the N-channel induced currents.

[0040] In a possible implementation manner, the first preset strategy in S52 includes the following content: Among the N-channel induced currents, select the induced current with the largest amplitude as the final induced current.

[0041] It should be noted that the induced current is not a current with a fixed amplitude, and its amplitude is dynamically changing. Therefore, in determining the induced current with the maximum amplitude, different selection criteria can be set to determine the final induced current. For example, the average values of the induced currents in each path can be compared, and the induced current with the largest average value can be used as the final induced current. Another example is that the maximum values of the induced currents in each path can be compared, and the induced current with the largest maximum value can be used as the final induced current. It should be noted that the above examples are only for illustration and do not constitute a limitation to this application. Different selection criteria from the above examples can be set according to actual needs to determine the final induced current.

[0042] In a possible implementation manner, the second preset policy in S53 includes the following: Among the N induced currents, filter out the induced currents with A less than 0; among the induced currents with A less than 0, select the induced current with the largest amplitude as the final induced current.

[0043] It should be noted that the induced current is not a current with a fixed amplitude, and its amplitude is dynamically changing. Therefore, the first thing to exclude is the induced current with A greater than 0 (i.e., exclude the induced current when the photoelectric induction unit enters the saturation state), and then select the induced current with the largest amplitude as the final induced current among the remaining induced currents (i.e., the induced current when the photoelectric induction unit is in the normal working state). In determining the induced current with the largest amplitude, different selection criteria can be set to determine the final induced current. For example, the average values of the induced currents in each path can be compared, and the induced current with the largest average value can be used as the final induced current. Another example is that the maximum values of the induced currents in each path can be compared, and the induced current with the largest maximum value can be used as the final induced current. It should be noted that the above examples are only for illustration and do not constitute a limitation to this application. Different selection criteria from the above examples can be set according to actual needs to determine the final induced current.

[0044] S6: Obtain the object signal of the scanning area according to the final induced current.

[0045] In a possible implementation manner, as Figure 3 shown, obtaining the object signal of the scanning area according to the final induced current includes: S61: Obtain the final induced signal according to the final induced current; S62: Obtain the interference signal according to the final induced signal; S63: Obtain the final object signal according to the final induced signal and the interference signal; S64: Define the final object signal as the object signal of the scanning area.

[0046] Embodiment 3

[0047] Embodiment 3 expands the technical solution provided in Embodiment 1 from the perspective of specific applications, mainly explaining how to determine the final object signal in N-channel induced currents. It is similar to the purpose of Embodiment 2, but Embodiment 3 provides a way that is not interconnected with Embodiment 2. Regarding the definitions of nouns in Embodiment 3, reference can be made to Embodiment 1 if not otherwise specified. For relevant information such as the detailed content, technical effects, and technical problems solved in each step of Embodiment 3, reference can be made to Embodiment 1 if not otherwise specified. Without violating the design purpose and physical laws, some optional or preferred options in Embodiment 1 are applicable to Embodiment 3.

[0048] This embodiment provides a method for processing lidar echo signals, which may include the following steps: S1: Transmit a laser signal to the scanning area and receive the echo signal, where the echo signal carries information about the scanning area; S2: Divide the echo signal into N sub-echo signals with different powers according to a preset ratio, where N is a positive integer not less than 2; S3: The lidar includes N types of photoelectric induction units with different sensitivities. The N types of photoelectric induction units are connected to the N sub-echo signals one by one, and the sensitivity of the photoelectric induction unit is negatively correlated with the power of the sub-echo signal; S4: Based on the N sub-echo signals and the N types of photoelectric induction units, obtain N-channel induced currents; S5: According to the preset current judgment condition, obtain the final induced current among the N-channel induced currents; In a possible implementation manner, as Figure 4 shown, obtaining the final induced current among the N-channel induced currents according to the preset current judgment condition includes: S51’: Respectively judge whether the N-channel induced currents reach the saturation currents of the corresponding photoelectric induction units, and define A as the difference between the induced current and the corresponding saturation current; S52’: Define the M-channel induced currents with A less than 0 as the final induced current, where M is a positive integer not greater than N.

[0049] S6: According to the final induced current, obtain the object signal of the scanning area.

[0050] In a possible implementation manner, as Figure 5 shown, obtaining the object signal of the scanning area according to the final induced current includes: S61’: According to the final induced current, obtain the final induced signal; S62’: According to the final induced signal, obtain the interference signal; S63’: According to the final induced signal and the interference signal, obtain the final object signal; S64’: Traverse the obtained M-channel final object signals and M-channel interference signals, and obtain the object signal of the scanning area from the M-channel final object signals according to the third preset strategy.

[0051] It should be noted that the induced current is not a current with a fixed amplitude, and its amplitude is dynamically changing. Therefore, the first thing to exclude is the induced current with A greater than 0 (that is, to exclude the induced current when the photoelectric induction unit enters the saturation state), and then separate the interference signal and the final object signal from the remaining induced current (that is, the final induction signal). Then, take the final object signal with the largest amplitude as the object signal of the scanning area. When determining the final object signal with the largest amplitude, different selection criteria can be set to determine the final induced current. For example, the means of each channel of the final object signal can be compared, and the final object signal with the largest mean is taken as the object signal of the scanning area. Another example is that the maximum values of each channel of the final object signal can be compared, and the final object signal with the largest maximum value is taken as the object signal of the scanning area. It should be noted that the above examples are only for illustration and do not constitute a limitation to this application. The selection criteria different from the above examples can be set according to actual needs to determine the object signal of the scanning area.

[0052] Combining Comparative Example 2 and Example 3, the object signals of the scanning area are determined from different practical perspectives. In Example 2, the unique final induced current is first determined, then the interference signal and the final object signal are separated from the final induced current, and the final object signal of the final induced current is taken as the object signal of the scanning area. In Example 3, all the induced currents when the photoelectric induction currents are in the normal working state are taken as the final induced currents, and the above-mentioned several channels of final induced currents are separated to obtain the corresponding number of final object signals. Then, the object signal of the scanning area is screened from the several channels of final object signals. The method of Example 2 makes a balance between the accuracy of the object signal of the scanning area and the overall calculation amount of acquisition; Example 3 focuses on analyzing the most core final object signal to determine the object signal of the scanning area, and the accuracy is higher than that of Example 2, but it will also bring a higher calculation amount.

[0053] Example 4

[0054] Embodiment 4 extends the technical solution provided in Embodiment 1 from the perspective of specific applications, mainly for analyzing and obtaining different interference signals, and also for analyzing and obtaining the interference signals in Embodiments 2 and 3. For the definitions of nouns in Embodiment 4, reference can be made to Embodiments 1 to 3 unless otherwise specified. For the detailed content, technical effects, technical problems solved, and other relevant information of each step in Embodiment 4, reference can be made to Embodiments 1 to 3 unless otherwise specified. Without violating the design purpose and physical laws, some optional or preferred options in Embodiments 1 to 3 are applicable to Embodiment 4.

[0055] For ease of understanding, examples of interference signals are given below.

[0056] LiDars can be subdivided into two schemes: coaxial and non-coaxial, according to the transmitting and receiving optical paths. The coaxial scheme means that the laser emitted by the laser and the laser received by the detector are coaxial; the non-coaxial scheme means that the laser emitted by the laser and the laser received by the detector are non-coaxial. During the optical path transmission of the laser emitted by the LiDAR, reflection phenomena will occur in the internal components of the LiDAR. Since this part of the reflected light (hereinafter referred to as the internal reflection signal) will be received by the photoelectric induction unit and an induced current will be generated. However, since the internal reflection signal does not reach the scanning area but is directly generated by the reflection of the internal components of the LiDAR. Therefore, the internal reflection signal does not carry information about the scanning area and belongs to a kind of noise signal. Since in the coaxial scheme, the emitted laser and the received laser are coaxial. Therefore, compared with the non-coaxial scheme, the noise problem caused by the internal reflection signal in the coaxial scheme is more serious than that in the non-coaxial scheme. In addition, according to the Friis transmission formula, the received power is inversely proportional to the square of the transmission distance. Since the LiDAR itself has a relatively small structure, the transmission distance of the internal reflection signal is much smaller than that of the target signal. Therefore, the received power of the internal reflection signal will be greater than that of the target signal, that is, compared with the target signal, the internal reflection signal is more likely to cause the photoelectric induction unit to enter the saturation state, resulting in the "broadening" of the electrical signal of the internal reflection signal and shielding the electrical signal of the target signal. Therefore, the internal reflection signal is a kind of interference signal.

[0057] When light travels from one medium to another (e.g., from air into water), reflection and refraction occur simultaneously at the interface. The above phenomenon also exists in the mapping of oceans and rivers by lidar. That is, when lidar precisely maps the seabed or riverbed, the detection signals emitted by the lidar will also undergo reflection and refraction at the water interface. Some of the detection signals will be reflected at the water interface and thus received by the photoelectric induction unit (hereinafter referred to as the interface reflection signal); some of the detection signals will be refracted at the water interface, reach the seabed or riverbed and then be reflected and received by the photoelectric induction unit (hereinafter referred to as the object signal). Similar to the internal reflection signal, since the interface reflection signal does not reach the scanning area (referring to the seabed or riverbed), it does not carry information about the scanning area. Compared with the transmission distance of the object signal, the transmission distance of the interface reflection signal is smaller. Therefore, the received power of the interface reflection signal may also be greater than that of the object signal, that is, compared with the object signal, the interface reflection signal is more likely to cause the photoelectric induction unit to enter the saturation state, resulting in the "broadening" of the electrical signal of the interface reflection signal and shielding the electrical signal of the object signal. Therefore, the interface reflection signal is also a kind of interference signal.

[0058] It should be noted that the above two main interference signals (i.e., the internal reflection signal and the interface reflection signal) do not conflict or exclude each other. That is, when using a coaxial lidar to precisely map oceans and rivers, it is possible for the above two interference signals to exist in the echo signal. If analyzing the electrical signal diagram of the echo signal, with the time domain as the horizontal axis, based on the transmission distances of different signals, there will be different orders, that is, the internal reflection signal (with the shortest transmission distance) is the closest to the origin, followed by the interface reflection signal (with a transmission distance longer than that of the internal reflection signal but shorter than that of the object signal), and finally the object signal.

[0059] This embodiment provides a method for identifying interference signals in the final induced current, as Figure 6 shown, which may include the following steps: SA: Determine whether the first moment corresponding to the first waveform signal in the final induced signal is within the first preset time range, where the first waveform signal is the first waveform signal in the final induced signal; SB: If the first moment is within the preset first time range, then determine the first waveform signal as the first interference sub-signal.

[0060] It should be noted that in the foregoing interference signal analysis, various signals have differentiability based on different transmission distances. Moreover, since the transmission distance of the internal reflection signal is much smaller than that of the interface reflection signal. Therefore, even if there are two interference signals, they can be identified from the waveform order and waveform time. If it is a single interference signal, it can be identified from the waveform time. For the internal reflection signal, the maximum value of its transmission distance can generally be regarded as twice the distance from the transmitting module to the lidar window. Since the internal dimensions of the lidar are known. Therefore, the latest appearance time corresponding to the internal reflection signal can be obtained through the above internal dimensions. If the time when the first waveform signal appears is before the above latest appearance time, it can generally be determined that the first waveform signal corresponds to the internal reflection signal. If the lidar is used to detect the ocean or river, it is generally set at a fixed position or installed on a drone. Whether it is set at a fixed position or installed on a drone, the approximate distance between the lidar and the horizontal plane is known (such as the position information of the drone or the relevant geographical database). Therefore, the approximate time range when the interface reflection signal appears can be obtained according to the above known approximate distance. If the time when the first waveform signal appears falls within the above time range, it can generally be determined that the first waveform signal corresponds to the interface reflection signal. In addition, in the actually received signals, in addition to the above interference signals, there are also some other noise signals (such as thermal noise / internal reflection signals of non-coaxial schemes), resulting in the waveforms in front of the first waveform signal not being fixed. Taking thermal noise as an example, due to its natural existence, although it may indeed cause changes in the waveform diagram, some noise signals have small amplitudes and relatively little impact on the target signal (generally, there will be no problem of shielding the target signal) and run through the entire time axis. Therefore, in actual judgment, a threshold needs to be set, and only signals exceeding this threshold are defined as the first waveform signal. This threshold can be set according to the threshold of thermal noise in the general period or about 30% of the saturation current threshold in the photoelectric induction unit.

[0061] In some possible embodiments, the interference signal further includes a second interference sub-signal; obtaining the interference signal according to the final induction signal further includes: SC: Judging whether the second time corresponding to the second waveform signal in the final induction signal is within the second preset time range, where the second waveform signal is the second waveform signal in the final induction signal; SD: If the second time is within the second preset time range, determine that the second waveform signal is the second interference sub-signal.

[0062] Specifically, what is described in the above possible embodiments is for the case where there are two interference signals at the same time, and the appearance times of the internal reflection signal and the interface reflection signal are matched according to their respective appearance time points, and classified according to the matching situation.

[0063] In some possible embodiments, if the interference signal satisfies the fourth preset strategy, it is determined that the interference signal includes an interface reflection signal, including: Obtain the corresponding interference signal point cloud based on the interference signal; Based on the interference signal point cloud, obtain an interference signal point cloud image; According to the interference signal point cloud image, determine whether there is a region parallel to the horizontal plane in the interference signal point cloud image; If there is a region parallel to the horizontal plane in the interference signal point cloud image, determine the region parallel to the horizontal plane as the interface region and determine that the interference signal includes an interface reflection signal.

[0064] It should be noted that after determining the existence of the interface reflection signal through the time range, further judgment and analysis can be carried out. Since the interface reflection signal is generally generated based on the mapping of lidar in the ocean or river. Therefore, the point cloud map formed by the real interface reflection signal is the sea level of the ocean (the water level of the river). Based on the characteristic that the point cloud map of the real interface reflection signal is parallel to the horizontal plane, the interference signal initially judged as the interface reflection signal can be further analyzed and judged, and the interference signal corresponding to the region parallel to the horizontal plane is determined as the interface reflection signal.

[0065] Embodiment 5

[0066] Embodiment 5 expands the technical solution provided in Embodiment 1 from the perspective of specific applications, mainly analyzes and obtains the final object signal, and also analyzes and obtains the final object signal in Embodiments 2 and 3. For the definitions of nouns in Embodiment 5, if not specifically stated, reference can be made to Embodiments 1 to 4. For the detailed content, technical effects, technical problems to be solved, and other relevant information of each step in Embodiment 5, if not specifically stated, reference can be made to Embodiments 1 to 4. Without violating the design purpose and physical laws, some optional or preferred options in Embodiments 1 to 4 are applicable to Embodiment 5.

[0067] This embodiment provides a method for determining a final object signal in a final induced current, which may include the following steps: Step 1: In the final induced signal, exclude the interference signal to obtain a first induced signal; Step 3: Determine the first induced signal as the final object signal.

[0068] In some possible embodiments, after excluding the interference signal in the final induced signal to obtain the first induced signal, it further includes: Step 2: Determine whether the third moment corresponding to the third waveform signal in the first induction signal is within the third preset time range, where the third waveform signal is the first waveform signal in the first induction signal; Step 3: If the third moment is within the third preset time range, determine that the first induction signal is the final target signal.

[0069] It should be noted that if the lidar is used for mapping of oceans and rivers, or when the distance to the scanning object has been preliminarily determined, since the distance to the scanning object has been preliminarily determined (the distance to the seabed or riverbed can be obtained approximately through sonar or relevant geographical data). Based on the above preliminarily determined distance, the approximate time range when the final target signal appears can be obtained. Therefore, based on the above characteristics, the first induction signal determined can be further analyzed and judged. By determining whether the moment (the third moment) when the first waveform signal appears is within the approximate time range (the third preset time range), it can be judged whether the first induction signal is the final target signal.

[0070] In some possible embodiments, as Figure 7 shown, determining that the first induction signal is the final target signal in Step 3 further includes: Sub-step 3.1: Determine that the first induction signal is a suspected target signal; Sub-step 3.2: Judge whether the suspected target signal meets the fifth preset strategy; Sub-step 3.3: If the suspected target signal meets the fifth preset strategy, determine that the suspected target signal is the final target signal.

[0071] In some possible embodiments, as Figure 8 shown, Sub-step 3.3 includes: Sub-step 3.3.1: Obtain the corresponding suspected target point cloud based on the suspected target signal; Sub-step 3.3.2: Based on the suspected target point cloud, obtain the suspected target point cloud image; Sub-step 3.3.3: According to the suspected target point cloud image, judge whether there is a continuous area in the suspected target point cloud image; Sub-step 3.3.4: If there is a continuous area in the suspected target point cloud image, the continuous area is the target area, and the signal corresponding to the target area is the final target signal.

[0072] It should be noted that for the first induction signal, it can also be further judged by the characteristics of surface continuity. In actual measurement, since there may be some object signals that are actually error signals, such as butterflies / birds / leaves flying in the air near the object of interest, or organisms swimming near the seabed / riverbed, which do not belong to the contour of the object of interest and are generally not the objects of interest scanned by lidar. Therefore, for lidar, the echo signal it generates is actually a kind of noise signal. However, since it is near the object of interest, it cannot be distinguished by the previous method. Therefore, the characteristics of surface continuity of the object can be used, that is, the real object of interest presents a plane / curved surface within a certain area range. Therefore, for the point cloud image composed of the point cloud reflected by the object surface, it will also have the same characteristics, that is, the point cloud image is a plane / curved surface within a certain area range. Based on the above characteristics, some possible noise signals in the object signal can be eliminated.

[0073] In some possible embodiments, as Figure 9 shown, determining the first induction signal as the final object signal in step 3 further includes: Sub-step 3.1': Determine the first induction signal as the initial object signal; Sub-step 3.2': Obtain the interface point cloud data according to the interface reflection signal; Sub-step 3.3': Obtain the object point cloud data according to the initial object signal in the scanning area; Sub-step 3.4': Correct the object point cloud data according to the refractive index between the interface area and the scanning area and the interface point cloud data to obtain the real object point cloud data; Sub-step 3.5': Determine the final object signal in the scanning area according to the real object point cloud data.

[0074] When lidar conducts precise mapping of the seabed and riverbed, the detection signal emitted by lidar will reflect and refract in the sea level / water interface. Part of the detection signal will be reflected and directly received by the photoelectric induction unit (hereinafter referred to as the interface reflection signal); part of the detection signal will refract, reach the seabed and riverbed and then be reflected and received by the photoelectric induction unit (hereinafter referred to as the object signal). However, due to the phenomenon of light refraction, the position information obtained by lidar will be incorrect. Take Figure 10For example, a laser beam refracts at the water interface, with the refracted beam actually arriving at point B. However, based on the principle that laser beams propagate in a straight line, the echo signal from point B actually indicates the location of point A. This can cause problems with LiDAR detection of the seabed or riverbed. Furthermore, as the transmission distance through seawater or river water increases, the deviation caused by this refraction increases, severely impacting LiDAR's ability to identify the seabed or riverbed. Therefore, correction of the object's point cloud data can be considered.

[0075] In some possible embodiments, such as Figure 11 As shown, step 3.4' includes: Step 3.4'.1: Calculate the interface incident angle of the light signal corresponding to each interface point cloud data based on each interface point cloud data α ; Specifically, the distance between the two points and the length of the three components (i.e., XYZ axes) in the first coordinate system can be obtained through the radar position information and the interface point cloud data. The interface incident angle can be obtained by combining the length of the three components with the inverse trigonometric function. α , the incident angle is the angle between the incident laser beam and the normal of the incident interface.

[0076] It should be noted that for ease of calculation, a standard coordinate system can be established with the XY axis parallel to the interface and the Z axis perpendicular to the interface. If the original coordinate system of the lidar is not a standard coordinate system, the coordinates of different points in the original coordinate system can be converted to the coordinates of the standard coordinate system using the coordinate system conversion formula. Although the position information is different in different coordinate systems, the distance between the same two points remains the same and does not change due to changes in the coordinate system.

[0077] In one possible implementation, Figure 12 As shown, step 3.4'.1 includes: Step 3.4'.1.1: Obtain the relative differences on the XYZ axes based on the radar position information and the interface point cloud data; It is understandable that ; ; .because X 相 、 Y 相 and Z 相 They all represent distances, so the absolute value is taken. 、 、 Indicates the position of the radar position information on the XYZ axis; 、 、 Indicates the position of the interface point cloud data on the XYZ three axes.

[0078] Step 3.4’.1.2: Obtain the incident angle of the laser beam when it reaches the water interface according to the respective relative differences on the XYZ axes .

[0079] It can be understood that the incident angle is calculated by the following formula:

[0080] It should be noted that X 相 , Y 相 and Z 相 are the lengths of the different components of the distance between the radar position information and the interface point cloud data on the XYZ axes. In this embodiment, through the arctangent function, the length of the projection of the line connecting the lidar and the reflection point on the XY plane is first obtained (i.e., ). Then, through Z 相 and the arctangent function, the incident angle of the laser beam when it reaches the water interface is obtained. In fact, in addition to using the arctangent function, other inverse trigonometric functions can also be used, and this application does not limit this.

[0081] Step 3.4’.2: Calculate the interface refraction angle according to the interface incident angle and the refractive index between both sides of the interface region. The interface refraction angle is the angle between the refracted laser beam and the normal of the water interface.

[0082] In a possible implementation manner, the interface refraction angle is calculated by the following formula: In the formula, is the relative refractive index between both sides of the interface region.

[0083] It can be understood that for the lidar, generally, a laser beam is emitted in the air and then may enter the ocean / river. At this time, takes the value of the ratio of the refractive index of the refraction side (water) to the refractive index of the incident side (air).

[0084] In a possible implementation manner, has a value range of [1.2, 1.5].

[0085] In a possible implementation manner, takes the value of 1.333.

[0086] Step 3.4’.3: Correct each object point cloud data based on the interface point cloud data, the interface incident angle and the interface refraction angle to obtain the real object point cloud data.

[0087] In a possible implementation manner, Step 3.4’.3 includes: Step 3.4’.3.1: Obtain the distance values of the interface point cloud data and the object point cloud data on the XYZ three axes according to the interface point cloud data and the object point cloud data, defined as 、 and ; Step 3.4’.3.2: Obtain the change values of the object point cloud data and the real object point cloud data on the XYZ three axes according to the interface incident angle 、the interface refraction angle 、 、 and ; Define the change values as 、 and ; Step 3.4’.3.3: Obtain the real object point cloud data according to the object point cloud data, 、 and .

[0088] Specifically, take the XYZ three axes as examples respectively for illustration.

[0089] Taking the Z axis as an example, Step 3.4’.3 includes: Step 3.4’.3.1: Obtain the distance value of the interface point cloud data and the object point cloud data on the Z axis according to the interface point cloud data and the object point cloud data ; Obtained through the following formula: In the formula, Z 对 is the Z-axis coordinate value of the object point cloud data, Z 界 is the Z-axis coordinate value of the interface point cloud data. Since represents the distance, the absolute value is taken.

[0090] Step 3.4’.3.2: Obtain the change value of the object point cloud data and the real object point cloud data on the Z axis according to the incident angle 、the refraction angle and , and obtain the change value ; Obtained by the following formula: It should be noted that taking Figure 10 as an example, the incident angle α = ∠ACE. Therefore, the distance between the reflected point cloud and the virtual refraction point cloud (i.e., CA) can be obtained by calculation. Due to the implicit constraint condition of CA = CB, therefore (i.e., CE) can be obtained by calculation.

[0091] Step 3.4’.3.3: According to the object point cloud data and , obtain the Z-axis coordinate value of the real object point cloud data.

[0092] Taking the X-axis as an example, Step 3.4’.3 includes: Step 3.4’.3.1: According to the interface point cloud data and the object point cloud data, obtain the distance value between the interface point cloud data and the object point cloud data on the Z-axis ; Obtained by the following formula: In the formula, X 对 is the X-axis coordinate value of the object point cloud data, X 界 is the X-axis coordinate value of the interface point cloud data. Since represents the distance, the absolute value is taken.

[0093] Step 3.4’.3.2: According to the incident angle , the refraction angle and , obtain the change value of the object point cloud data and the real object point cloud data on the x-axis; Obtained by the following formula: It should be noted that taking Figure 10 as an example, for the X-axis, Figure 2 is the projection of the laser beam transmission process on the XZ plane (i.e., Figure 10 the horizontal axis in is the X-axis and the vertical axis is the Z-axis). At this time, since the position information of the virtual refraction point cloud is obtained based on the data of the real refraction point cloud, the time for the reflected point to reach the virtual refraction point cloud is the same as the time for the reflected point to reach the real refraction point cloud. Further derivation shows that their projections on the XZ plane are also equal, that is, there is an implicit constraint condition of CA = CB, so (i.e., BE) can be obtained through calculation. In addition, since the current calculation is carried out using the projection on the XZ plane, in the projection on the XZ plane, ∠ACE is not necessarily , and ∠BCE is not necessarily . Therefore, it cannot be directly calculated through trigonometric functions , and it can only be calculated based on the implicit constraint condition of CA = CB .

[0094] Step 3.4’.3.3: According to the object point cloud data and , obtain the X-axis coordinate value of the real object point cloud data.

[0095] Taking the Y-axis as an example, Step 3.4’.3 includes: Step 3.4’.3.1: According to the interface point cloud data and the object point cloud data, obtain the distance value between the interface point cloud data and the object point cloud data on the Y-axis ; Obtained through the following formula: In the formula, Y 对 is the Y-axis coordinate value of the object point cloud data, Y 界 is the Y-axis coordinate value of the interface point cloud data. Since represents the distance, the absolute value is taken.

[0096] Step 3.4’.3.2: According to the incident angle , the refraction angle and , obtain the change value of the object point cloud data and the real object point cloud data on the Y-axis ; Obtained through the following formula: It should be noted that taking Figure 10 as an example, for the Y-axis, Figure 2 is the projection of the transmission process of the laser beam on the YZ plane (i.e., Figure 10 the horizontal axis in is the Y-axis and the vertical axis is the Z-axis). At this time, since the position information of the virtual refraction point cloud is obtained according to the data of the real refraction point cloud, the time for the reflection point to reach the virtual refraction point cloud is the same as the time for the reflection point to reach the real refraction point cloud. Therefore, their projections on the YZ plane are also equal, that is, there is an implicit constraint condition of CA = CB. Therefore (i.e., BE) can be obtained through Calculated. In addition, since the current calculation is performed using the projection on the YZ plane, in the projection on the YZ plane, ∠ACE is not necessarily , ∠BCE is not necessarily . Therefore, it cannot be directly calculated through trigonometric functions , and can only be calculated based on the implicit constraint condition of CA = CB .

[0097] Step 3.4’.3.3: According to the object point cloud data and , obtain the Y-axis coordinate value of the real object point cloud data.

[0098] Embodiment 6 Embodiment 6 provides a computer-readable storage medium, which is suitable for being loaded by a processor to execute a method for processing lidar echo signals provided in Embodiments 1 to 5 of this example.

[0099] Embodiment 7 Embodiment 7 provides a lidar, including: A laser emission module, which is used to emit laser signals to the scanning area; A laser reception module, the laser reception module includes a beam splitting unit, and the beam splitting unit is used to divide the echo signal into N sub-echo signals with different powers according to a preset ratio, where N is a positive integer not less than 2; the laser reception unit also includes N photoelectric induction units with different sensitivities, and the N photoelectric induction units are connected to the N sub-echo signals in one-to-one correspondence, and the sensitivity of the photoelectric induction unit is negatively correlated with the power of the sub-echo signal, and the N photoelectric induction units are used to receive the N sub-echo signals; A judgment module, which obtains N induction currents based on the N sub-echo signals and the N optical reception units; obtains the final induction current among the N induction currents according to the preset current judgment condition; and obtains the object signal of the scanning area according to the final induction current.

[0100] In a possible implementation manner, the beam splitting unit is a beam splitter.

[0101] In a possible implementation manner, the lidar further includes a memory and a processor, and the processor is used to call a computer program stored in the memory to execute a method for processing lidar echo signals provided in Embodiments 1 to 5 of this example.

[0102] In a possible implementation manner, the lidar further includes a readable storage medium, which is suitable for being loaded by a processor to execute a method for processing lidar echo signals provided in Embodiments 1 to 5 of this example.

[0103] The execution order of each step in the above embodiments is only an example and does not limit this application. The steps can also be executed in other execution orders, and no specific limitation is made here.

[0104] The device provided in the embodiment of this application belongs to the same concept as the method in the above embodiment. Any method provided in the above embodiment can be run on the device. For the specific implementation process, please refer to Embodiments 1 to 5, which will not be elaborated here.

[0105] The above has introduced in detail a method for processing lidar echo signals, a storage medium, and a lidar provided in the embodiments of this application. Specific examples are used in this article to elaborate on the principle and implementation manner of this application. The description of the above embodiments is only used to help understand the method and its core idea of this application; at the same time, for those skilled in the art, according to the idea of this application, there will be changes in the specific implementation manner and application scope. In summary, the content of this specification should not be construed as a limitation to this application.

Claims

1. A method for processing lidar echo signals, characterized in that The method includes: Emitting a laser signal to a scanning area and receiving an echo signal, where the echo signal carries information of the scanning area; Dividing the echo signal into N sub-echo signals with different powers according to a preset ratio, where N is a positive integer not less than 2; The lidar includes N types of photoelectric induction units with different sensitivities, and the N types of photoelectric induction units are connected to the N sub-echo signals one by one, and the sensitivity of the photoelectric induction unit and the power of the sub-echo signal are in a negative correlation; Based on the N sub-echo signals and the N types of photoelectric induction units, obtaining N induction currents; According to a preset current judgment condition, obtaining a final induction current from the N induction currents; According to the final induction current, obtaining an object signal of the scanning area.

2. The method for processing lidar echo signals according to claim 1, wherein The obtaining the final induction current from the N induction currents according to the preset current judgment condition includes: Respectively judging whether the N induction currents reach the saturation currents of the corresponding photoelectric induction units, and defining A as the difference between the induction current and the corresponding saturation current; If A of the N induction currents are all less than 0, then obtaining the final induction current from the N induction currents according to a first preset strategy; If some of A of the N induction currents are equal to 0, then obtaining the final induction current from the N induction currents according to a second preset strategy.

3. The method for processing lidar echo signals according to claim 2, wherein, The obtaining the object signal of the scanning area according to the final induction current includes: According to the final induction current, obtaining a final induction signal; According to the final induction signal, obtaining an interference signal; According to the final induction signal and the interference signal, obtaining a final object signal; Defining the final object signal as the object signal of the scanning area.

4. The method for processing lidar echo signals according to claim 1, wherein The obtaining the final induction current from the N induction currents according to the preset current judgment condition includes: Respectively judging whether the N induction currents reach the saturation currents of the corresponding photoelectric induction units, and defining A as the difference between the induction current and the corresponding saturation current; Defining the M induction currents with A less than 0 as the final induction current, where M is a positive integer not greater than N.

5. The method for processing lidar echo signals according to claim 4, wherein, The obtaining the object signal of the scanning area according to the final induction current includes: According to the final induction current, obtaining a final induction signal; According to the final induction signal, obtaining an interference signal; According to the final induction signal and the interference signal, obtaining a final object signal; Traversing to obtain M final object signals and M interference signals, and obtaining the object signal of the scanning area from the M final object signals according to a third preset strategy.

6. The method for processing lidar echo signals according to claim 3 or 5, wherein The interference signal includes a first interference sub-signal; The obtaining the interference signal according to the final induction signal includes: Judging whether the first moment corresponding to the first waveform signal in the final induction signal is within a first preset time range, where the first waveform signal is the first waveform signal in the final induction signal; If the first moment is within the preset first time range, then determining the first waveform signal as the first interference sub-signal.

7. The method for processing lidar echo signals according to claim 6, wherein The interference signal further includes a second interference sub-signal; The obtaining the interference signal according to the final induction signal further includes: Determine whether the second moment corresponding to the second waveform signal in the final induction signal is within the second preset time range, where the second waveform signal is the second waveform signal located in the final induction signal; If the second moment is within the second preset time range, determine that the second waveform signal is a second interference sub-signal.

8. The method for processing lidar echo signals according to claim 6, wherein If the interference signal meets the fourth preset strategy, determine that the interference signal includes an interface reflection signal, including: Obtain the corresponding interference signal point cloud based on the interference signal; Obtain an interference signal point cloud image based on the interference signal point cloud; According to the interference signal point cloud image, determine whether there is a region parallel to the horizontal plane in the interference signal point cloud image; If there is a region parallel to the horizontal plane in the interference signal point cloud image, determine that the region parallel to the horizontal plane is the interface region and determine that the interference signal includes an interface reflection signal.

9. The method for processing lidar echo signals according to claim 3 or 5, characterized in that, The obtaining the final object signal according to the final induction signal and the interference signal includes: Exclude the interference signal from the final induction signal to obtain a first induction signal; Determine that the first induction signal is the final object signal.

10. The method for processing lidar echo signals according to claim 9, wherein, After excluding the interference signal from the final induction signal to obtain a first induction signal, it further includes: Determine whether the third moment corresponding to the third waveform signal in the first induction signal is within the third preset time range, where the third waveform signal is the first waveform signal in the first induction signal; If the third moment is within the third preset time range, determine that the first induction signal is the final object signal.

11. The method for processing lidar echo signals according to claim 9, wherein, The determining that the first induction signal is the final object signal further includes: Determine that the first induction signal is a suspected object signal; Determine whether the suspected object signal meets the fifth preset strategy; If the suspected object signal meets the fifth preset strategy, determine that the suspected object signal is the final object signal.

12. The method for processing lidar echo signals according to claim 11, wherein, The if the suspected object signal meets the fifth preset strategy, determining that the suspected object signal is the final object signal includes: Obtain the corresponding suspected object point cloud based on the suspected object signal; Obtain a suspected object point cloud image based on the suspected object point cloud; According to the suspected object point cloud image, determine whether there is a continuous region in the suspected object point cloud image; If there is a continuous region in the suspected object point cloud image, the continuous region is the object region, and the signal corresponding to the object region is the final object signal.

13. The method for processing lidar echo signals according to claim 8, wherein The obtaining the final object signal according to the final induction signal and the interference signal includes: Exclude the interference signal from the final induction signal to obtain a first induction signal; Determine that the first induction signal is the final object signal.

14. The method for processing lidar echo signals according to claim 13, wherein If the interference signal includes an interface reflection signal, the determining that the first induction signal is the final object signal further includes: Determine that the first induction signal is an initial object signal; Obtain interface point cloud data according to the interface reflection signal; Obtain object point cloud data according to the initial object signal of the scanning region; Correct the object point cloud data according to the refractive index between the interface area and the scanning area and the interface point cloud data to obtain the real object point cloud data; Determine the final object signal of the scanning area according to the real object point cloud data.

15. A readable storage medium, characterized in that, The readable storage medium is suitable for being loaded by a processor to execute the steps in the lidar echo signal processing method according to any one of claims 1-14.

16. A lidar, characterized in that, The lidar includes: A laser emission module for emitting a laser signal to a scanning area; A laser reception module, the laser reception module includes a beam splitting unit, the beam splitting unit is used to divide the echo signal into N sub-echo signals with different powers according to a preset ratio, and N is a positive integer not less than 2; the laser reception unit further includes N photoelectric induction units with different sensitivities, and the N photoelectric induction units are connected to the N sub-echo signals in one-to-one correspondence, and the sensitivity of the photoelectric induction unit is negatively correlated with the power of the sub-echo signal, and the N photoelectric induction units are used to receive the N sub-echo signals; A judgment module, the judgment module obtains N induction currents based on the N sub-echo signals and N light receiving units; obtains a final induction current from the N induction currents according to a preset current judgment condition; and obtains an object signal of the scanning area according to the final induction current.

17. The lidar according to claim 16, wherein The lidar further includes a memory and a processor, and the processor is used to call a computer program stored in the memory to execute the steps in the lidar echo signal processing method according to any one of claims 1-14.

18. The lidar according to claim 16, characterized in that, The lidar further includes a readable storage medium, and the readable storage medium is suitable for being loaded by the processor to execute the steps in the lidar echo signal processing method according to any one of claims 1-14.

Images