Measurement Method, System and Medium of LED Optical Radar Based on Pseudo-Random Modulation

Abstract

The present invention relates to the technical field of lidar detection, and particularly to a measurement method, system and medium of an LED lidar based on pseudo-random modulation. The method modulates an LED beam generated by an LED light source based on a target pseudo-random code to obtain a modulated beam, and emits the modulated beam; receives the backscattered light of the modulated beam, preprocesses the backscattered light, and converts the preprocessed backscattered light into an electrical signal; uses a photon counter to perform high-speed integration operation compensation processing on the electrical signal; demodulates the electrical signal, and calculates the aerosol extinction coefficient in the environment to be measured according to the demodulation result. In this way, the influence of optical noise can be reduced, and the LED lidar system can be adapted to daytime use.

Description

Technical Field

[0001] The present invention relates to the field of optical radar detection technology, and in particular to a measurement method, system and medium of an LED optical radar based on pseudo-random modulation. Background Art

[0002] With the rapid development of radar detection technology, radar detection is used in more and more detection scenarios. At present, most existing radar detection systems use lasers as light sources. At present, in urban areas with concentrated populations, high-power lasers are large in size and expensive in price, and have not been fully applied in cities. On this basis, in order to maximize the utilization benefits of optical radars, it is necessary to develop optical radars that use light-emitting diodes (LEDs) as new light sources. This light source has low cost, low energy consumption, and is more stable, making it easy to promote and use on a large scale. However, LED optical radars are easily affected by other light sources because of their poor collimation. The demand for optical radars is mainly during the day when light noise is strong. It can be seen that existing optical radars are difficult to eliminate the influence of light noise and cannot be used during the day. Summary of the invention

[0003] The present invention provides a measurement method, system and medium of an LED optical radar based on pseudo-random modulation, so as to solve the problem that the existing optical radar is difficult to eliminate the influence of light noise and cannot be used in daytime.

[0004] In order to achieve the above object, the present invention is implemented by the following technical solutions:

[0005] The present invention provides a measurement method of an LED optical radar based on pseudo-random modulation, which is applied to an LED optical radar system. The LED optical radar system includes an LED light source and a photon counter. The method includes:

[0006] determining a target pseudo-random code;

[0007] Modulating the LED light beam generated by the LED light source based on the target pseudo-random code to obtain a modulated light beam, and emitting the modulated light beam;

[0008] receiving backscattered light of the modulated light beam, preprocessing the backscattered light, and converting the preprocessed backscattered light into an electrical signal;

[0009] The photon counter is used to perform high-speed integral operation compensation processing on the electrical signal;

[0010] The electrical signal is demodulated and the aerosol extinction coefficient in the measured environment is calculated based on the demodulation result.

[0011] Optionally, determining the target pseudo-random code includes:

[0012] Determine the length of the target pseudo-random code according to the clock signal of the photon counter, and generate the target pseudo-random code based on the length.

[0013] Optionally, before modulating the LED beam generated by the LED light source with the target pseudo-random code to obtain a modulated beam, the method further includes:

[0014] Adjust the overlap rate between the diffusion of the LED beam generated by the LED light source within a distance of 100 - 200 meters and the field of view of the receiver to be higher than a preset overlap rate threshold.

[0015] Optionally, receiving the backscattered light of the modulated beam and preprocessing the backscattered light includes:

[0016] Collect the backscattered light of the LED lidar system and obtain the environmental factors in the environment to be measured;

[0017] Filter out impurities in the backscattered light according to the environmental factors;

[0018] Wherein, the environmental factors include the atmospheric humidity and the atmospheric particle concentration of the environment to be measured.

[0019] Optionally, the target pseudo-random code is generated by a pseudo-random code generator, the LED beam generated by the LED light source is generated under the drive of a drive circuit, the input end of the pseudo-random code generator is connected to the output end of the photon counter, and the output end of the pseudo-random code generator is connected to the input end of the drive circuit through a digital-to-analog conversion module.

[0020] Optionally, the drive circuit includes:

[0021] Resistors R1, R1, R2, R3, R4, R5, R6, R7, R8, R9, R10, R11, R12, R13, R14, R15, R16, R17, R18, R19, R20, capacitors C1, C2, C3, C4, C5, C6, C7, C8, C9, transistors T1, T2, T3, T4, T5, diodes D1 and D2;

[0022] Among them, the first ends of the resistor R1, the resistor R2, the resistor R3, the resistor R4, the resistor R5, the resistor R6, the resistor R7, the resistor R10, and the resistor R11 are all connected to the first end of the resistor R12. The second end of the resistor R1 is connected to the first end of the capacitor C1 and the collector of the triode T1. The emitter of the triode T1 is grounded. The second end of the capacitor C1 is connected to the second end of the resistor R2 and the base of the triode T2. The base of the triode T1 is connected to the second end of the resistor R3 and the first end of the capacitor C2. The second end of the capacitor C2 is connected to the collector of the triode T2. The emitter of the triode T2 is connected to the emitter of the triode T1. The second end of the resistor R5 is connected to the negative electrode of the diode D1. The positive electrode of the diode D1 is connected to the second end of the resistor R6, the first end of the capacitor C3, and the collector of the triode T3. The emitter of the triode T3 is connected to the emitter of the triode T1. The second end of the capacitor C3 is connected to the second end of the resistor R7 and the base of the triode T4. The base of the triode T3 is connected to the first end of the resistor R9, the first end of the capacitor C4, and the first end of the resistor R8. The second end of the capacitor C4 is connected to the second end of the resistor R8, the second end of the resistor R10, and the positive electrode of the diode D2. The collector of the triode T4 is connected to the negative electrode of the diode D2, the second end of the resistor R11, the first end of the capacitor C6, the base of the triode T5, the first end of the resistor R13, and the first end of the resistor R14;

[0023] The second end of the capacitor C6 is connected to the first end of the resistor R18, the first end of the resistor R19, and the base of the triode T6. The second end of the resistor R18 is connected to the first end of the resistor R12, the collector of the triode T6, and the first end of the capacitor C9. The second end of the capacitor C9 is grounded. The emitter of the triode T6 is connected to the first end of the resistor R20 and the first end of the capacitor C7. The second end of the resistor R19 is grounded, and the second end of the resistor R20 is connected to the second end of the resistor R19. The second end of the capacitor C7 and the second end of the resistor R20 form a first output terminal;

[0024] The second end of the resistor R13 is connected to the second end of the resistor R12. The emitter of the triode T5 is connected to the first ends of the capacitor C5, the resistor R15, the resistor R16, and the resistor R17. The second end of the resistor R14 is connected to the second ends of the capacitor C5, the resistor R16, and the resistor R17 and then grounded. The first end of the capacitor C8 is connected to the first end of the resistor R12, and the second end of the capacitor C8 is grounded. The first end of the capacitor C8 and the collector of the triode T5 form a second output terminal;

[0025] Wherein, the output end of the pseudo-random code generator is connected to the base of the triode T5 in the driving circuit through a digital-to-analog conversion module.

[0026] Optionally, the LED lidar system further includes a scanning stage, and the LED light source is disposed on the scanning stage. The method further includes:

[0027] Controlling the scanning stage to move according to a preset trajectory to adjust the modulated light beam emitted by the LED light source at different positions on the preset trajectory;

[0028] Wherein, the preset trajectory includes a moving time, a moving angle, and a moving direction, and the moving time, the moving angle, and the moving direction are determined based on the resolution of the LED light source and the integration time of the photon counter.

[0029] In a second aspect, the present application further provides an LED lidar system, including: a barrel, a lens, an LED light source, a pseudo-random code generator, a digital-to-analog conversion circuit, a driving circuit, a receiving mechanism, a photon counter, and a demodulation mechanism. The barrel includes a first side and a second side. The first side is provided with a first opening, and the second side is provided with a second opening. The size of the first opening is smaller than that of the second opening. The LED light source is disposed at the first opening. The lens is disposed on the side of the LED light source facing the second opening. The driving circuit and the pseudo-random code generator are both connected to the LED light source. The output end of the receiving mechanism and the output end of the photon counter are connected to the display;

[0030] The pseudo-random code generator is used to generate a target pseudo-random code of an electrical signal and send the target pseudo-random code of the electrical signal to the digital-to-analog conversion circuit;

[0031] The digital-to-analog conversion circuit is used to convert the target pseudo-random code of the electrical signal into a target pseudo-random code of an analog signal and then send it to the driving circuit;

[0032] The driving circuit is used to modulate and drive the LED beam generated by the LED light source based on the target pseudo-random code to obtain a modulated beam;

[0033] The lens is used to perform beam shaping on the LED beam;

[0034] The receiver is used to receive the backscattered light of the modulated beam, preprocess the backscattered light, and convert the preprocessed backscattered light into an electrical signal;

[0035] The photon counter is used to perform high-speed integration operation compensation processing on the electrical signal by using the photon counter;

[0036] The demodulation mechanism is used to demodulate the electrical signal, and the photon counter is further used to calculate the aerosol extinction coefficient in the environment to be measured according to the demodulation result.

[0037] In a third aspect, the present application provides a computer-readable storage medium, on which a computer program is stored, and when the program is executed by a processor, the method steps described in the first aspect are implemented.

[0038] Advantageous effects:

[0039] The measurement method of the lidar based on pseudo-random modulation provided by the present invention modulates the LED beam generated by the LED light source based on the target pseudo-random code to obtain a modulated beam, and emits the modulated beam; receives the backscattered light of the modulated beam, preprocesses the backscattered light, and converts the preprocessed backscattered light into an electrical signal; performs high-speed integration operation compensation processing on the electrical signal by using a photon counter; demodulates the electrical signal, and calculates the aerosol extinction coefficient in the environment to be measured according to the demodulation result. In this way, the aerosol extinction coefficient in the environment can be accurately measured to determine the optical characteristics of the environment to be measured. Among them, by using the target pseudo-random code to adjust the LED beam, the influence of optical noise can be reduced, so that the LED lidar system is adapted to daytime use; on this basis, by using high-speed integration operation to compensate for the influence of the coding length of the target pseudo-random code on the spatial resolution, the detection accuracy of the LED lidar system can be improved. Description of the drawings

[0040] Figure 1 It is a flowchart of a measurement method of a lidar based on pseudo-random modulation according to a preferred embodiment of the present invention;

[0041] Figure 2 It is a circuit diagram of a driving circuit according to a preferred embodiment of the present invention;

[0042] Figure 3 It is a schematic structural diagram of an LED lidar system according to a preferred embodiment of the present invention. Detailed implementation manners

[0043] The technical solution of the present invention will be described clearly and completely below. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without making creative efforts belong to the scope of protection of the present invention.

[0044] Please refer to Figure 1 , an embodiment of the present application provides a measurement method for an optical radar based on pseudo-random modulation, which is applied to an LED optical radar system. The LED optical radar system includes an LED light source and a photon counter. The method includes:

[0045] Determine the target pseudo-random code;

[0046] Modulate the LED beam generated by the LED light source based on the target pseudo-random code to obtain a modulated beam, and emit the modulated beam;

[0047] Receive the backscattered light of the modulated beam, preprocess the backscattered light, and convert the preprocessed backscattered light into an electrical signal;

[0048] Use a photon counter to perform high-speed integration operation compensation processing on the electrical signal;

[0049] Demodulate the electrical signal, and calculate the aerosol extinction coefficient in the environment to be measured according to the demodulation result.

[0050] In this embodiment, the aerosol extinction coefficient can reflect the optical characteristics in the environment to be measured.

[0051] In the above measurement method for an optical radar based on pseudo-random modulation, by using the target pseudo-random code to adjust the LED beam, the influence of optical noise can be reduced, so that the LED optical radar system is suitable for daytime use; on this basis, by using high-speed integration operation to compensate for the influence of the coding length of the target pseudo-random code on the spatial resolution, the detection accuracy of the LED optical radar system can be improved.

[0052] Optionally, determining the target pseudo-random code includes:

[0053] Determine the length of the target pseudo-random code according to the clock signal of the photon counter, and generate the target pseudo-random code based on the length.

[0054] In this optional implementation manner, when determining the length of the target pseudo-random code according to the clock signal of the photon counter, the purpose is to make the target pseudo-random code synchronized with the clock signal of the photon counter. In this way, a target pseudo-random code with a suitable length can be determined, avoiding the influence on the detection accuracy caused by the target pseudo-random code being too long or too short.

[0055] Optionally, before modulating the LED beam generated by the LED light source based on the target pseudo-random code to obtain the target beam, the method further includes:

[0056] Adjust the overlap rate between the diffusion of the LED beam generated by the LED light source and the field of view of the receiver at a distance of 100 - 200 meters to be higher than a preset overlap rate threshold.

[0057] It should be noted that due to the LED collimation error, in this embodiment, by adjusting the overlap rate between the diffusion of the LED beam generated by the LED light source and the field of view of the receiver at a distance of 100 - 200 meters to be higher than a preset overlap rate threshold, the LED light source can be calibrated to minimize the power loss problem of the LED light source caused by beam diffusion, and avoid the problem of poor directivity of the LED affecting the detection accuracy.

[0058] Optionally, calculating the aerosol extinction coefficient in the environment to be measured according to the demodulation result includes:

[0059] Obtain the environmental factors in the environment to be measured;

[0060] Calculate the aerosol extinction coefficient in the environment to be measured according to the environmental factors and the demodulation result;

[0061] Wherein, the environmental factors include the atmospheric humidity and the atmospheric particle concentration of the environment to be measured.

[0062] It should be noted that both the atmospheric humidity and the atmospheric particle concentration in the environment are factors affecting the atmospheric aerosol optical properties. Therefore, the atmospheric humidity and the atmospheric particle concentration in the environment may affect the extinction coefficient. In this embodiment, the influences of the atmospheric humidity and the atmospheric particle concentration of the environment to be measured are fully considered, and impurities in the backscattered light are filtered according to the atmospheric humidity and the atmospheric particle concentration of the environment to be measured, which can facilitate more accurate measurement of the extinction coefficient of the environment.

[0063] Specifically, in one example, when calculating the aerosol extinction coefficient in the environment to be measured according to the environmental factors and the demodulation result, the following calculation relationship can be satisfied:

[0064]

[0065] In the formula, σ(R) is the aerosol extinction coefficient, r is the distance, P(r) is the lidar signal, r0 is the critical point for inversion calculation, P(r0) is the lidar signal at the critical point, σ(r0) is the extinction coefficient at the critical point, dr′ represents the differential of the distance, P(R′) and r′ are identifiers in the integral term, π is a constant, and N0 is the environmental factor fitting distribution value.

[0066] Optionally, in this factual example, the target pseudo-random code is generated by a pseudo-random code generator, the LED beam generated by the LED light source is generated under the drive of a drive circuit, the input end of the pseudo-random code generator is connected to the output end of the photon counter, and the output end of the pseudo-random code generator is connected to the input end of the drive circuit through a digital-to-analog conversion module.

[0067] Please refer to Figure 2 , optionally, the drive circuit includes:

[0068] Resistors R1, R1, R2, R3, R4, R5, R6, R7, R8, R9, R10, R11, R12, R13, R14, R15, R16, R17, R18, R19, R20, capacitors C1, C2, C3, C4, C5, C6, C7, C8, C9, transistors T1, T2, T3, T4, T5, diodes D1 and D2;

[0069] Among them, the first ends of resistor R1, resistor R2, resistor R3, resistor R4, resistor R5, resistor R6, resistor R7, resistor R10, and resistor R11 are all connected to the first end of resistor R12. The second end of resistor R1 is connected to the first end of capacitor C1 and the collector of transistor T1. The emitter of transistor T1 is grounded. The second end of capacitor C1 is connected to the second end of resistor R2 and the base of transistor T2. The base of transistor T1 is connected to the second end of resistor R3 and the first end of capacitor C2. The second end of capacitor C2 is connected to the collector of transistor T2. The emitter of transistor T2 is connected to the emitter of transistor T1. The second end of resistor R5 is connected to the negative pole of diode D1. The positive pole of diode D1 is connected to the second end of resistor R6, the first end of capacitor C3, and the collector of transistor T3. The emitter of transistor T3 is connected to the emitter of transistor T1. The second end of capacitor C3 is connected to the second end of resistor R7 and the base of transistor T4. The base of transistor T3 is connected to the first end of resistor R9, the first end of capacitor C4, and the first end of resistor R8. The second end of capacitor C4 is connected to the second end of resistor R8, the second end of resistor R10, and the positive pole of diode D2. The collector of transistor T4 is connected to the negative pole of diode D2, the second end of resistor R11, the first end of capacitor C6, the base of transistor T5, the first end of resistor R13, and the first end of resistor R14;

[0070] The second terminal of capacitor C6 is connected to the first terminal of resistor R18, the first terminal of resistor R19, and the base of transistor T6. The second terminal of resistor R18 is connected to the first terminal of resistor R12, the collector of transistor T6, and the first terminal of capacitor C9. The second terminal of capacitor C9 is grounded. The emitter of transistor T6 is connected to the first terminal of resistor R20 and the first terminal of capacitor C7. The second terminal of resistor R19 is grounded, and the second terminal of resistor R20 is connected to the second terminal of resistor R19. The second terminal of capacitor C7 and the second terminal of resistor R20 form a first output terminal;

[0071] The second terminal of resistor R13 is connected to the second terminal of resistor R12. The emitter of transistor T5 and the first terminal of capacitor C5, the first terminal of resistor R15, the first terminal of resistor R16, and the first terminal of resistor R17 are connected. The second terminal of resistor R14 is connected to the second terminal of capacitor C5, the second terminal of resistor R16, and the second terminal of resistor R17 and then grounded. The first terminal of capacitor C8 is connected to the first terminal of resistor R12. The second terminal of capacitor C8 is grounded. The first terminal of capacitor C8 and the collector of transistor T5 form a second output terminal;

[0072] Among them, the output terminal of the pseudo-random code generator is connected to the base of the transistor T5 in the drive circuit through a digital-to-analog conversion module.

[0073] In this embodiment, the first terminal of resistor R1 is further connected to a +10V power supply, and the second terminal of resistor R9 is further connected to a -6V power supply.

[0074] It should be understood that the above drive circuit includes three partial functions: pulse generation, reference signal separation, and current drive. A high-frequency oscillation signal is generated through the circuit composed of resistors R1 to R11, capacitors C1 to C4, and transistors T1 to T4. The circuit composed of capacitor C6 to the first output terminal is used for signal shunting. The circuit composed of resistors R12 to the second output terminal is used as a drive output to drive the LED light source. Among them, the output terminal of the pseudo-random code generator is connected to the base of the transistor T5 in the drive circuit through a digital-to-analog conversion module, which can achieve the purpose of modulation according to the pseudo-random code, with a simple structure and easy to implement.

[0075] It is worth emphasizing that in the prior art, the period of the drive circuit is relatively long, which will affect the accuracy of the measurement results. In this embodiment, through the designed drive circuit above, the frequency of the LED light source can be increased as much as possible, the noise of the LED can be compensated, multiple measurements can be achieved in a short time, and the implementation cost is low.

[0076] It should be noted that the photon counter includes a high-speed integral operation unit, and the high-speed integral operation unit is used for high-speed integral operation compensation processing of the electrical signal.

[0077] It should be noted that when the length of the target pseudo-random code is too long, resulting in lag, through high-speed integral operation compensation processing, the lag situation can be significantly improved, and further eliminate the adverse effects brought by the too long length of the target pseudo-random code.

[0078] Optionally, the LED lidar system further includes a scanning stage, the LED light source is disposed on the scanning stage, and the method further includes:

[0079] Controlling the scanning stage to move according to a preset trajectory to adjust the modulated light beam emitted by the LED light source at different positions on the preset trajectory;

[0080] Wherein, the preset trajectory includes a moving time, a moving angle, and a moving direction, and the moving time, the moving angle, and the moving direction are determined based on the resolution of the LED light source and the integration time of the photon counter.

[0081] It should be noted that in a certain measurement, the emission direction of the LED light source is fixed. In this optional embodiment, in order to achieve continuous measurement in multiple directions, by controlling the scanning stage to move according to a preset trajectory to adjust the modulated light beam emitted by the LED light source at different positions on the preset trajectory, in this way, continuous measurement in multiple directions can be achieved.

[0082] Specifically, determining the angular velocity based on the resolution of the LED light source and the integration time of the photon counter, including but not limited to the moving time, the moving angle, and the moving direction, can ensure the accuracy in continuous measurement in multiple directions, and avoid the situation of untimely signal reception and out-of-sync caused by changing the angle or the direction.

[0083] Optionally, it should be noted that the detection of the LED lidar is affected by pulse width, frequency, photon counter resolution, pseudo-random code modulation coding length, receiver integration times, etc. In a preferred embodiment, numerical analysis methods can also be used to optimize the parameter configuration of the system to improve the measurement accuracy, such as optimizing the length of the pseudo-random code or the coding displacement.

[0084] In an example, the signal flow during the measurement includes a pseudo-random code generator, a drive circuit, an led light source, a transmitting mechanism (telescope), a receiving mechanism (telescope and photomultiplier tube), a photon counter (including an integration circuit, and at the same time, the photon counter should maintain a synchronous connection with the pseudo-random code generator), and finally a demodulation mechanism.

[0085] The above-mentioned measurement method of optical radar based on pseudo-random modulation uses an LED light source to generate a light beam, and correspondingly involves a driving circuit that can realize pseudo-random modulation. Through this overall design, compared with the existing optical radar system, the implementation cost is reduced, and it is easy to use and promote.

[0086] See also Figure 3 , the embodiment of the present application also provides an LED optical radar system, characterized in that it includes: a lens barrel, a lens, an LED light source, a pseudo-random code generator, a digital-to-analog conversion circuit, a driving circuit, a receiving mechanism, a photon counter, and a demodulation mechanism, the lens barrel includes a first side and a second side, the first side is provided with a first opening, the second side is provided with a second opening, the size of the first opening is smaller than the second opening, the LED light source is provided at the first opening, the lens is provided on the side of the LED light source facing the second opening, the driving circuit and the pseudo-random code generator are both connected to the LED light source, and the output end of the receiving mechanism and the output end of the photon counter are connected to the display;

[0087] The pseudo-random code generator is used to generate a target pseudo-random code of an electrical signal, and send the target pseudo-random code of the electrical signal to a digital-to-analog conversion circuit;

[0088] The digital-to-analog conversion circuit is used to convert the target pseudo-random code of the electrical signal into the target pseudo-random code of the analog signal and then send it to the driving circuit;

[0089] The driving circuit is used to modulate and drive the LED light beam generated by the LED light source based on the target pseudo-random code to obtain a modulated light beam;

[0090] The lens is used to perform beam processing on the LED light beam;

[0091] The receiver is used to receive the backscattered light of the modulated light beam, preprocess the backscattered light, and convert the preprocessed backscattered light into an electrical signal;

[0092] The photon counter is used to perform high-speed integral operation compensation processing on the electrical signal using the photon counter;

[0093] The demodulation mechanism is used to perform demodulation processing on the electrical signal, and the photon counter is also used to calculate the aerosol extinction coefficient in the environment to be measured according to the demodulation result.

[0094] In this embodiment, the lens barrel can be directly nested on the LED light source, and the lens can be a silicone lens. In one example, the silicone lens can be covered on the surface of the LED light source. Among them, converting the reflected light received by the receiver into a pulse signal for display can visually display the detected signal, facilitating the user to perform subsequent step processing.

[0095] In one example, the above LED lidar system may further include a display mechanism, and the measurement result is displayed through the display mechanism, which is intuitive and convenient.

[0096] For the above LED lidar system, a driving circuit is used to drive the LED light source to generate an LED beam. The driving circuit has a simple structure, and using the LED light source to generate the LED beam as the light source of the lidar system can reduce the cost of the lidar system. At the same time, a lens is used to perform beam shaping on the LED beam, which is lighter in weight and shorter in focal length, and can improve the convenience of the LED lidar system.

[0097] The above LED lidar system can implement each embodiment of the above optical radar control method based on pseudo-random modulation and achieve the same beneficial effects, which will not be elaborated here.

[0098] The embodiment of the present application further provides a computer-readable storage medium, on which a computer program is stored, and when the program is executed by a processor, the method steps described in the first aspect are implemented.

[0099] The preferred specific embodiments of the present invention have been described in detail above. It should be understood that those of ordinary skill in the art can make many modifications and variations according to the concept of the present invention without creative work. Therefore, all technical solutions that can be obtained by those skilled in the art in the technical field of the present invention based on the concept of the present invention through logical analysis, reasoning, or limited experiments on the basis of the prior art should be within the protection scope determined by the claims.

Claims

1. A measurement method of an LED optical radar based on pseudo-random modulation, applied to an LED optical radar system, the LED optical radar system comprising an LED light source and a photon counter, characterized in that, The method includes: Determine a target pseudo-random code; Modulate the LED beam generated by the LED light source based on the target pseudo-random code to obtain a modulated beam, and emit the modulated beam; Receive the backscattered light of the modulated beam, and convert the backscattered light into an electrical signal; Perform high-speed integral operation compensation processing on the electrical signal using the photon counter; Demodulate the electrical signal, and calculate the aerosol extinction coefficient in the environment to be measured according to the demodulation result; The determination of the target pseudo-random code includes: Determine the length of the target pseudo-random code according to the clock signal of the photon counter, and generate the target pseudo-random code based on the length; Among them, when calculating the aerosol extinction coefficient in the environment to be measured, the following calculation relationship is satisfied: In the formula, σ(r) is the aerosol extinction coefficient, r is the distance, P(r) is the lidar signal, r0 is the critical point for inversion calculation, P(r0) is the lidar signal at the critical point, σ(r0) is the extinction coefficient at the critical point, dr' represents the differential of the distance, P(r') and r' are identifiers in the integral term, π is a constant, and N0 is the environmental factor fitting distribution value.

2. The measurement method of the LED optical radar based on pseudo-random modulation according to claim 1, characterized in that Before modulating the LED beam generated by the LED light source based on the target pseudo-random code to obtain a modulated beam, the method further includes: Adjust the overlap rate between the diffusion of the LED beam generated by the LED light source at a distance between 100 - 200 meters and the field of view of the receiving mechanism to be higher than a preset overlap rate threshold.

3. The measurement method of the LED optical radar based on pseudo-random modulation according to claim 1, characterized in that The calculation of the aerosol extinction coefficient in the environment to be measured according to the demodulation result includes: Obtain the environmental factors in the environment to be measured; Calculate the aerosol extinction coefficient in the environment to be measured according to the environmental factors and the demodulation result; Among them, the environmental factors include the atmospheric humidity and the atmospheric particle concentration of the environment to be measured.

4. The measurement method of the LED optical radar based on pseudo-random modulation according to claim 1, wherein The target pseudo-random code is generated by a pseudo-random code generator, the LED beam generated by the LED light source is generated under the drive of a drive circuit, the input end of the pseudo-random code generator is connected to the output end of the photon counter, and the output end of the pseudo-random code generator is connected to the input end of the drive circuit through a digital-to-analog conversion module.

5. The measurement method of the LED optical radar based on pseudo-random modulation according to claim 4, characterized in that The drive circuit includes: Resistors R1, R2, R3, R4, R5, R6, R7, R8, R9, R10, R11, R12, R13, R14, R15, R16, R17, R18, R19, R20, capacitors C1, C2, C3, C4, C5, C6, C7, C8, C9, transistors T1, T2, T3, T4, T5, diodes D1 and D2; Among them, the first ends of the resistor R1, the resistor R2, the resistor R3, the resistor R4, the resistor R5, the resistor R6, the resistor R7, the resistor R10, and the resistor R11 are all connected to the first end of the resistor R12. The second end of the resistor R1 is connected to the first end of the capacitor C1 and the collector of the triode T1. The emitter of the triode T1 is grounded. The second end of the capacitor C1 is connected to the second end of the resistor R2 and the base of the triode T2. The base of the triode T1 is connected to the second end of the resistor R3 and the first end of the capacitor C2. The second end of the capacitor C2 is connected to the collector of the triode T2. The emitter of the triode T2 is connected to the emitter of the triode T1. The second end of the resistor R5 is connected to the negative pole of the diode D1. The positive pole of the diode D1 is connected to the second end of the resistor R6, the first end of the capacitor C3, and the collector of the triode T3. The emitter of the triode T3 is connected to the emitter of the triode T1. The second end of the capacitor C3 is connected to the second end of the resistor R7 and the base of the triode T4. The base of the triode T3 is connected to the first end of the resistor R9, the first end of the capacitor C4, and the first end of the resistor R8. The second end of the capacitor C4 is connected to the second end of the resistor R8, the second end of the resistor R10, and the positive pole of the diode D2. The collector of the triode T4 is connected to the negative pole of the diode D2, the second end of the resistor R11, the first end of the capacitor C6, the base of the triode T5, the first end of the resistor R13, and the first end of the resistor R14; The second end of the capacitor C6 is connected to the first end of the resistor R18, the first end of the resistor R19, and the base of the triode T6. The second end of the resistor R18 is connected to the first end of the resistor R12, the collector of the triode T6, and the first end of the capacitor C9. The second end of the capacitor C9 is grounded. The emitter of the triode T6 is connected to the first end of the resistor R20 and the first end of the capacitor C7. The second end of the resistor R19 is grounded, and the second end of the resistor R20 is connected to the second end of the resistor R19. The second end of the capacitor C7 and the second end of the resistor R20 form a first output terminal; The second end of the resistor R13 is connected to the second end of the resistor R12, the emitter of the transistor T5 is connected to the first end of the capacitor C5, the first end of the resistor R15, the first end of the resistor R16 and the first end of the resistor R17, the second end of the resistor R14 is connected to the second end of the capacitor C5, the second end of the resistor R16 and the second end of the resistor R17 and then grounded, the first end of the capacitor C8 is connected to the first end of the resistor R12, the second end of the capacitor C8 is grounded, and the first end of the capacitor C8 and the collector of the transistor T5 form a second output end; Wherein, the output end of the pseudo-random code generator is connected to the base of the transistor T5 in the driving circuit through a digital-to-analog conversion module.

6. The measurement method of the LED optical radar based on pseudo-random modulation according to claim 1, characterized in that The LED optical radar system further includes a scanning platform, the LED light source is arranged on the scanning platform, and the method further includes: Controlling the scanning stage to move according to a preset track to adjust the LED light source to emit a modulated light beam at different positions of the preset track; The preset trajectory includes moving time, moving angle and moving direction, and the moving time, moving angle and moving direction are determined based on the resolution of the LED optical radar system and the integration time of the photon counter.

7. An LED optical radar system, characterized in that, include: A lens barrel, a lens, an LED light source, a pseudo-random code generator, a digital-to-analog conversion circuit, a driving circuit, a receiving mechanism, a photon counter, a demodulation mechanism, and a processing unit, wherein the lens barrel comprises a first side and a second side, the first side is provided with a first opening, the second side is provided with a second opening, the size of the first opening is smaller than the second opening, the LED light source is provided at the first opening, the lens is provided at a side of the LED light source facing the second opening, the driving circuit and the pseudo-random code generator are both connected to the LED light source, the output end of the receiving mechanism is connected to the input end of the photon counter, and the output end of the photon counter is connected to a display; The pseudo-random code generator is used to generate a target pseudo-random code of an electrical signal, and send the target pseudo-random code of the electrical signal to a digital-to-analog conversion circuit; The digital-to-analog conversion circuit is used to convert the target pseudo-random code of the electrical signal into the target pseudo-random code of the analog signal and then send it to the driving circuit; The driving circuit is used to modulate and drive the LED light beam generated by the LED light source based on the target pseudo-random code to obtain a modulated light beam; The lens is used to perform beam processing on the LED light beam; The receiving mechanism is used to receive the backscattered light of the modulated light beam, preprocess the backscattered light, and convert the preprocessed backscattered light into an electrical signal; The photon counter is used to perform high-speed integral operation compensation processing on the electrical signal using the photon counter; The demodulation mechanism is used to demodulate the electrical signal; The processing unit is used to invert and calculate the aerosol extinction coefficient in the environment to be measured according to the demodulation result; The target pseudo-random code for generating the electrical signal comprises: Determine the length of the target pseudo-random code according to the clock signal of the photon counter, and generate the target pseudo-random code based on the length; Among them, when calculating the aerosol extinction coefficient in the environment to be measured, the following calculation relationship is satisfied: In the formula, σ(r) is the aerosol extinction coefficient, r is the distance, P(r) is the lidar signal, r0 is the critical point for inversion calculation, P(r0) is the lidar signal at the critical point, σ(r0) is the extinction coefficient at the critical point, dr' represents the differential of the distance, P(r') and r' are identifiers in the integral term, π is a constant, and N0 is the environmental factor fitting distribution value.

8. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the program is executed by a processor, it implements the method steps described in any one of claims 1-6.

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