Target Detection Method and Device Based on LiDAR

Abstract

This application provides a target detection method and apparatus based on lidar. The method includes: when the operating temperature of the OPA chip exceeds a specified temperature range, determining target phase correction parameters and target temperature compensation values ​​for each phase shifter based on the latest operating temperature; adjusting the phase of each phase shifter using the target phase correction parameters; and controlling the temperature of an optical antenna unit using the determined target temperature compensation values ​​through a thermal compensation unit to adjust the phase of the optical antenna in the optical antenna unit. The phase-adjusted OPA chip is then used to detect the target. This application solves the problem of low detection accuracy caused by changes in the refractive index of the phase modulator due to temperature fluctuations, thereby reducing errors during detection and improving the detection accuracy and reliability of the lidar.

Description

Technical Field

[0001] This application relates to the field of lidar, and more specifically, to a target detection method and apparatus based on lidar. Background Technology

[0002] In LiDAR systems, the optical phased array (OPA), as one of the core optical components, plays a crucial role in non-mechanical beam steering and rapid scanning. The OPA chip, based on silicon photonics technology, synthesizes a directional beam by precisely adjusting the phase of light waves in each channel, thus achieving three-dimensional imaging of the surrounding environment. However, changes in ambient temperature have a certain impact on target detection in LiDAR systems; for example, Figure 1 This is a schematic diagram of light intensity distribution at different temperatures in related technologies. For example... Figure 1 As shown, the normalized far-field intensity distribution obtained from a 128-channel optical phased array (OPA) is displayed when the temperature of the photonic integrated chip (PIC) changes. With increasing or decreasing temperature, the main lobe angle of the beam may shift, accompanied by an increase in side lobe intensity, which reduces detection accuracy. Summary of the Invention

[0003] This application provides a target detection method and apparatus based on lidar to at least solve the technical problems in related technologies.

[0004] According to one aspect of the embodiments of this application, a target detection method based on a lidar is provided. The lidar includes an OPA chip, and the OPA chip is provided with a temperature sensor, an optical antenna unit, and a thermal compensation unit. The temperature sensor is used to detect the operating temperature of the OPA chip. The method includes:

[0005] When using the lidar for detection, the operating temperature of the OPA chip is obtained in real time through the temperature sensor.

[0006] If the operating temperature of the OPA chip is detected to exceed the specified temperature range, the target phase correction parameter of each phase shifter in the OPA chip and the target temperature compensation value of the thermal compensation unit are determined based on the latest detected operating temperature of the OPA chip. The phase of each phase shifter is adjusted using the determined target phase correction parameter of each phase shifter. The temperature of the optical antenna unit is controlled by the thermal compensation unit using the determined target temperature compensation value, so that the phase of the optical antenna in the optical antenna unit is adjusted. The specified temperature range is determined based on the operating temperature recorded during the last phase adjustment.

[0007] The OPA chip with phase adjustment is used to detect the target, and the detection result of the target is obtained.

[0008] According to another aspect of the embodiments of this application, a target detection device based on lidar is also provided. The lidar includes an OPA chip, and the OPA chip is provided with a temperature sensor, an optical antenna unit, and a thermal compensation unit for the optical antenna unit. The temperature sensor is used to detect the operating temperature of the OPA chip. The device includes:

[0009] The acquisition unit is used to acquire the operating temperature of the OPA chip in real time through the temperature sensor when the lidar is used for detection.

[0010] A determining unit is configured to, when the operating temperature of the OPA chip is detected to exceed a specified temperature range, determine, based on the latest detected operating temperature of the OPA chip, a target phase correction parameter for each phase shifter in the OPA chip and a target temperature compensation value for the thermal compensation unit, and use the determined target phase correction parameters for each phase shifter to perform phase adjustment on each phase shifter. Furthermore, the thermal compensation unit uses the determined target temperature compensation value to perform temperature control on the optical antenna unit, thereby adjusting the phase of the optical antenna in the optical antenna unit. The specified temperature range is determined based on the operating temperature recorded during the last phase adjustment.

[0011] The detection unit is used to detect the target using the phase-adjusted OPA chip and obtain the detection result of the target.

[0012] According to another aspect of the embodiments of this application, a computer-readable storage medium is also provided, wherein a computer program is stored in the computer program, and the computer program is configured to perform the steps in any of the above method embodiments when it is run.

[0013] According to another aspect of the embodiments of this application, a computer program product or computer program is provided, the computer program product or computer program including computer instructions stored in a computer-readable storage medium. A processor of a computer device reads the computer instructions from the computer-readable storage medium, and the processor executes the computer instructions, causing the computer device to perform the steps in any of the method embodiments described above.

[0014] According to another aspect of the embodiments of this application, an electronic device is also provided, including a memory and a processor, wherein the memory stores a computer program, and the processor is configured to perform the steps of any of the above method embodiments through the computer program.

[0015] This application addresses the issue of low detection accuracy caused by temperature fluctuations in phase modulators due to changes in refractive index during lidar detection. By employing a temperature sensor to acquire the operating temperature of the OPA chip in real time when the OPA chip's operating temperature exceeds a specified range, the application determines the target phase correction parameters for each phase shifter and the target temperature compensation value for the thermal compensation unit based on the latest detected OPA chip operating temperature. This allows for phase adjustment of each phase shifter, and the thermal compensation unit uses the determined target temperature compensation value to control the temperature of the optical antenna unit, thereby adjusting the phase of the optical antenna. The phase-adjusted OPA chip is then used to detect the target, yielding the detection result. This solves the problem in related technologies where temperature fluctuations cause changes in the refractive index of the phase modulator, resulting in low detection accuracy. Precise phase and temperature correction ensures accurate beam focusing and direction control, reducing errors during detection and improving the lidar's detection accuracy and reliability. Furthermore, real-time temperature compensation and phase correction can adapt to a wider range of temperature variations, maintaining consistent detection performance of the lidar under different ambient temperatures. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of light intensity distribution at different temperatures in a related art according to an embodiment of this application;

[0017] Figure 2 This is a schematic flowchart of an optional target detection method based on lidar according to an embodiment of this application;

[0018] Figure 3 This is a schematic diagram of an optional OPA chip according to an embodiment of this application;

[0019] Figure 4 This is a structural block diagram of an optional lidar-based target detection device according to an embodiment of this application;

[0020] Figure 5 This is a computer system architecture block diagram of an optional electronic device according to an embodiment of this application. Detailed Implementation

[0021] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present application, and not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative effort should fall within the scope of protection of the present application.

[0022] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of this application described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0023] According to one aspect of the embodiments of this application, a target detection method based on lidar is provided. The lidar includes an OPA chip, on which a temperature sensor, an optical antenna unit, and a thermal compensation unit are disposed. The temperature sensor is used to detect the operating temperature of the OPA chip. Figure 2 This is a flowchart illustrating an optional target detection method based on lidar according to an embodiment of this application, as shown below. Figure 2 As shown, the process of this method may include the following steps:

[0024] Step S202: When using LiDAR for detection, the operating temperature of the OPA chip is obtained in real time through a temperature sensor.

[0025] Step S204: If the operating temperature of the OPA chip is detected to be outside the specified temperature range, the target phase correction parameter of each phase shifter in the OPA chip and the target temperature compensation value of the thermal compensation unit are determined according to the latest detected operating temperature of the OPA chip. The phase of each phase shifter is adjusted using the determined target phase correction parameter of each phase shifter. The temperature of the optical antenna unit is controlled by the determined target temperature compensation value through the thermal compensation unit so that the phase of the optical antenna in the optical antenna unit is adjusted. The specified temperature range is determined based on the operating temperature recorded during the last phase adjustment.

[0026] Step S206: Use the phase-adjusted OPA chip to detect the target and obtain the detection result of the target.

[0027] The LiDAR-based target detection method in this embodiment can be applied to the field of LiDAR, including scenarios such as autonomous vehicles, robot navigation, and terrain mapping. A specific application scenario is high-precision target detection under varying environmental temperatures. In this scenario, the LiDAR needs to maintain its performance over a wide temperature range to ensure the normal operation of the vehicle's autonomous driving functions under all weather conditions.

[0028] In related technologies, lidar systems using OPA chips, especially when using optical phased arrays for beam control, suffer from the temperature sensitivity of OPA chips. Temperature fluctuations can cause changes in the refractive index of the phase modulator, which in turn affects the direction and shape of the beam, resulting in relatively low detection accuracy.

[0029] To at least partially solve the above-mentioned technical problems, in this embodiment, by integrating a temperature sensor into the lidar, the operating temperature of the OPA chip can be monitored in real time. When the operating temperature exceeds the current preset range, the target phase correction parameters and target temperature compensation values ​​are obtained, and the phase shifter and thermal compensation unit are quickly adjusted to maintain the consistency of the beam phase, thereby ensuring the detection accuracy and stability of the lidar under different temperature conditions.

[0030] It should be noted that LiDAR can include an OPA chip. LiDAR is a technology that uses laser beams for distance measurement and imaging, capable of generating high-resolution three-dimensional (3D) environmental maps. It is commonly used in autonomous vehicles, robot navigation, and terrain mapping. The OPA chip is a key component of LiDAR, achieving beam scanning without mechanical movement by controlling the phase of multiple beams, thus enabling rapid and flexible target detection. (Reference) Figure 3 This is a schematic diagram of an optional OPA chip according to an embodiment of this application. For example... Figure 3 As shown, the OPA chip incorporates a temperature sensor, optical antenna unit, phase shifter, classifier, and thermal compensation unit (not shown in the figure). The OPA chip can be connected to an EIC (Electronic Interface Control), which manages and coordinates the communication and control signals between the various electronic components of the lidar (such as the temperature sensor and phase shifter) and the central control unit. Specifically, the EIC receives data from the temperature sensor, performs algorithm processing, determines the phase adjustment value of the phase shifter, and controls the heating or cooling of the thermal compensation unit. The EIC module may integrate hardware and software functions, enabling intelligent analysis of temperature changes and rapid response, thereby achieving stable operation and high-precision beam control under different temperature environments.

[0031] A temperature sensor is used to monitor the temperature of the OPA chip in real time. In practice, the temperature sensor should be placed in a location on the chip that accurately reflects overall temperature changes, such as near the phase shifter, at the center of the OPA chip, or at the location of heat sources during OPA chip operation. Of course, one or more temperature sensors can be placed within the OPA chip. In some cases, to more accurately monitor the temperature distribution across the entire OPA chip, a network of multiple temperature sensors can be set up. Each temperature sensor monitors a different area on the chip, and the data is then aggregated to achieve more precise temperature control and compensation.

[0032] The phase shifter is one of the core components on the OPA chip, used to change the phase of the light beam, thereby controlling its direction. The optical antenna unit is a key component for transmitting and receiving the light beam. It typically consists of a series of integrated miniature optical antennas, which can be waveguide ports, couplers, or specially designed nanophotonic devices.

[0033] The primary function of an optical antenna unit is to control the direction of the beam in space, enabling non-mechanical scanning detection of targets. OPA chips typically integrate a thermal compensation unit. This unit is a device that actively regulates the local temperature of the chip, ensuring optimal performance of the optical antenna unit under varying ambient temperatures through heating or cooling. Thermal compensation units usually include miniature heaters, heat sinks, or thermoelectric coolers. These components adjust the temperature in real time based on feedback from temperature sensors, thereby maintaining the phase stability and beam quality of the optical antenna unit. The classifier can be a component used for signal processing or data analysis. It can be responsible for processing feedback signals received from the OPA chip, or for identifying and classifying different modes (or beam shapes) emitted by the OPA, etc.

[0034] The specified temperature range is a temperature interval determined based on the operating temperature recorded during the last phase adjustment. It is used to determine whether the current temperature requires triggering phase and temperature compensation mechanisms. This range is dynamic and depends on the actual operating temperature of the OPA chip. For example, in a LiDAR system used in autonomous vehicles, the OPA chip's operating temperature was recorded as 30°C during the last calibration, with a corresponding set temperature range of 28°C to 32°C. When the ambient temperature changes, the temperature sensor detects that the OPA chip's temperature has risen to 35°C, exceeding the specified temperature range.

[0035] For example, when using lidar for detection, the operating temperature of the OPA chip detected by the temperature sensor can be monitored in real time. If the operating temperature of the OPA chip is found to exceed the specified temperature range, the target phase correction parameters of each phase shifter in the OPA chip and the target temperature compensation value of the thermal compensation unit are determined based on the latest operating temperature. The phase of the phase shifter is then automatically adjusted according to the determined target phase correction parameters to compensate for refractive index changes caused by temperature variations, ensuring the focusing and directionality of the beam in the far field. Based on the target temperature compensation value, the local temperature of the optical antenna unit is controlled using the thermal compensation unit to further fine-tune the phase of the beam, ensuring the stability of the beam performance under temperature changes. After phase and temperature adjustments are completed, the operating temperature detected by the temperature sensor continues to be acquired in real time. If the operating temperature does not exceed the current specified temperature range, lidar detection can continue using the corrected OPA chip.

[0036] The embodiments provided in this application demonstrate that, when using a lidar for detection, the operating temperature of the OPA chip is acquired in real time via a temperature sensor. If the operating temperature of the OPA chip exceeds a specified temperature range, the target phase correction parameters for each phase shifter and the target temperature compensation value for the thermal compensation unit are determined based on the latest detected operating temperature of the OPA chip. This allows for phase adjustment of each phase shifter, and the determined target temperature compensation value is used by the thermal compensation unit to control the temperature of the optical antenna unit, thereby adjusting the phase of the optical antenna. The phase-adjusted OPA chip is then used to detect the target, yielding the detection result. This solves the problem in related technologies where temperature fluctuations cause changes in the refractive index of the phase modulator, resulting in low detection accuracy. Precise phase and temperature correction ensures accurate beam focusing and direction control, reducing errors during detection and improving the detection accuracy and reliability of the lidar. Furthermore, real-time temperature compensation and phase correction can adapt to a wider range of temperature changes, maintaining consistent detection performance of the lidar under different ambient temperatures.

[0037] In an exemplary embodiment, the lidar is provided with a first temperature compensation table and a second temperature compensation table. The first temperature compensation table includes phase correction parameters for each phase shifter at each preset temperature in a set of preset temperatures, and the second temperature compensation table includes temperature compensation values ​​for the thermal compensation unit at each preset temperature in the set of preset temperatures. Step S204 includes: finding a first target preset temperature that matches the latest operating temperature of the detected OPA chip from the first temperature compensation table; determining the phase correction parameters of each phase shifter at the first target preset temperature as target phase correction parameters for each phase shifter; finding a second target preset temperature that matches the latest operating temperature of the detected OPA chip from the second temperature compensation table; and determining the temperature compensation value of the thermal compensation unit at the second target preset temperature as the target temperature compensation value of the thermal compensation unit.

[0038] It should be noted that the lidar can be equipped with a first temperature compensation table and a second temperature compensation table. The first temperature compensation table records the optimal phase correction parameters for each phase shifter on the OPA chip at a series of preset temperatures. These phase correction parameters are obtained through calibration experiments in the laboratory and can compensate for phase errors caused by refractive index changes due to temperature variations, thereby ensuring that the beam steering and focusing performance of the OPA chip remains consistent at different temperatures. The second temperature compensation table is a set of data at a series of preset temperatures, recording the temperature compensation values ​​of the thermal compensation unit. These compensation values ​​are used to adjust the temperature of the optical antenna unit in the OPA chip through local heating or cooling, further fine-tuning the beam phase to ensure optimal optical performance is maintained even with temperature changes. These temperature compensation values ​​are obtained through calibration experiments in the laboratory. Generally, the generation process of the first and second temperature compensation tables can be carried out through the same experiment, that is, the selected preset temperatures can be the same.

[0039] In one example, the lidar needs to operate within a temperature range of 10°C to 50°C, with preset temperatures in 5°C increments: 10°C, 15°C, ..., 45°C, 50°C. Under laboratory conditions, each preset temperature was meticulously calibrated, and the phase correction parameters for each phase shifter (used in the first temperature compensation table) and the temperature compensation values ​​for the thermal compensation unit (used in the second temperature compensation table) were recorded. While the lidar is running, a temperature sensor continuously monitors the operating temperature of the OPA chip. For example, if the latest detected operating temperature is 32°C, the preset temperature closest to 32°C, either 30°C or 35°C, is retrieved from the first temperature compensation table. Assuming 30°C is selected as the first target preset temperature, the phase correction parameters for each phase shifter at that temperature will be determined as the target phase correction parameters for each phase shifter.

[0040] Simultaneously, the second target preset temperature closest to 32℃ will be found from the second temperature compensation table, also assumed to be 30℃. The temperature compensation value of the thermal compensation unit at this temperature will be determined as the target temperature compensation value of the thermal compensation unit, and these target parameters will be applied to control the phase shifter and the thermal compensation unit to ensure that the OPA chip can generate a stable and accurate beam at the current temperature.

[0041] This embodiment utilizes a first temperature compensation table and a second temperature compensation table to enable the lidar to maintain stable optical performance over a wide temperature range. Even with rapid temperature changes, preset compensation parameters can be quickly applied using a lookup table, preventing beam performance degradation caused by temperature variations. Furthermore, using both tables reduces the real-time calculation requirements of the lidar during actual operation, avoiding the need for extensive iterative calibrations when temperatures change. The use of lookup tables allows for rapid determination of compensation parameters, significantly reducing calibration time and energy consumption.

[0042] In an exemplary embodiment, the lidar is provided with a first temperature compensation table and a second temperature compensation table, wherein the first temperature compensation table includes phase correction parameters for each phase shifter at each preset temperature in a set of preset temperatures, and the second temperature compensation table includes temperature compensation values ​​for the thermal compensation unit at each preset temperature in a set of preset temperatures; step S204 includes:

[0043] Based on the latest operating temperature of the detected OPA chip, a first preset temperature and a second preset temperature are retrieved from a first temperature compensation table. The first and second preset temperatures are the two preset temperatures in the first temperature compensation table that are closest to the latest operating temperature of the OPA chip. The phase correction parameter of each phase shifter at the first preset temperature is determined as the first phase correction value for each phase shifter, and the phase correction parameter of each phase shifter at the second preset temperature is determined as the second phase correction value for each phase shifter. The first preset temperature is less than the second preset temperature. The difference between the latest operating temperature of the OPA chip and the first preset temperature is multiplied by a first designated coefficient corresponding to each phase shifter, and the result is summed with the first phase correction value of each phase shifter to determine the target phase correction parameter for each phase shifter. The first designated coefficient corresponding to each phase shifter is obtained by subtracting the difference between the second and first phase correction values ​​of each phase shifter and dividing by the difference between the second and first preset temperatures.

[0044] Based on the latest operating temperature of the detected OPA chip, the third and fourth preset temperatures are retrieved from the second temperature compensation table. These three preset temperatures are the two closest to the latest operating temperature of the OPA chip in the second temperature compensation table. The temperature compensation value of the thermal compensation unit at the third preset temperature is determined as the first temperature correction value of the thermal compensation unit, and the temperature compensation value at the fourth preset temperature is determined as the second temperature correction value of the thermal compensation unit. The third preset temperature is lower than the fourth preset temperature. The target temperature compensation value of the thermal compensation unit is determined by multiplying the difference between the latest operating temperature of the OPA chip and the third preset temperature by a second specified coefficient and summing the result with the first temperature correction value. The second specified coefficient is obtained by subtracting the first temperature correction value from the second temperature correction value and dividing by the difference between the fourth and third preset temperatures.

[0045] It should be noted that the lidar can be equipped with a first temperature compensation table and a second temperature compensation table. The first temperature compensation table records the optimal phase correction parameters for each phase shifter on the OPA chip under a series of preset temperatures. Each phase shifter may require different phase correction values ​​at different temperatures to compensate for the refractive index changes caused by temperature variations, thereby maintaining the accuracy of beam steering. The second temperature compensation table records the temperature compensation values ​​of the thermal compensation unit under a series of preset temperatures. The temperature compensation values ​​can be used to fine-tune the local temperature of the OPA chip to further optimize optical performance. Specifically, the temperature compensation values ​​of the thermal compensation unit can be used to adjust part or all of the temperature of the optical antenna unit, thereby adjusting the phase of the optical antenna unit.

[0046] The first preset temperature and the second preset temperature are the two temperature points in the first temperature compensation table that are closest to the latest detected operating temperature of the OPA chip, wherein the first preset temperature is lower than the second preset temperature. The third preset temperature and the fourth preset temperature are the two temperature points in the second temperature compensation table that are closest to the latest detected operating temperature of the OPA chip, wherein the third preset temperature is lower than the fourth preset temperature. Optionally, the first preset temperature may be the same as or different from the third preset temperature, and the second preset temperature may be the same as or different from the fourth preset temperature.

[0047] The first specified coefficient is obtained by subtracting the first phase correction value from the second phase correction value of each phase shifter, and then dividing by the difference between the second preset temperature and the first preset temperature. The second specified coefficient is obtained by subtracting the first temperature correction value from the second temperature correction value, and then dividing by the difference between the fourth preset temperature and the third preset temperature. The first and second specified coefficients can be used for linear interpolation to determine the target phase / temperature compensation value at the current operating temperature of the OPA chip by calculating the rate of change of the phase / temperature correction value between two preset temperature points (first / second preset temperature, third / fourth preset temperature).

[0048] In one example, the lidar needs to operate within a temperature range of 10°C to 50°C, with preset temperatures in 5°C increments: 10°C, 15°C, ..., 45°C, 50°C. Given that the latest detected operating temperature is 32°C...

[0049] In the first temperature compensation table, 32℃ is closest to 30℃ and 35℃; therefore, 30℃ is the first preset temperature, and 35℃ is the second preset temperature. The phase correction parameter for each phase shifter at 30℃ is determined as the first phase correction value, and the phase correction parameter for each phase shifter at 35℃ is determined as the second phase correction value. The first specified coefficient is calculated by dividing the difference between the second and first phase correction values ​​by the temperature difference between 30℃ and 35℃. Multiplying the temperature difference between 30℃ and 32℃ by the first specified coefficient and then adding the first phase correction value yields the target phase correction parameter for each phase shifter.

[0050] In the second temperature compensation table, 32℃ is closest to 30℃ and 35℃. 30℃ is the third preset temperature, and 35℃ is the fourth preset temperature. The temperature compensation value of the thermal compensation unit at 30℃ is determined as the first temperature correction value, and the temperature compensation value of the thermal compensation unit at 35℃ is determined as the second temperature correction value. The second specified coefficient is obtained by dividing the difference between the second temperature correction value and the first temperature correction value by the temperature difference between 35℃ and 30℃. The temperature difference between 32℃ and 3℃ is multiplied by the second specified coefficient, and then added to the first temperature correction value to determine the target temperature compensation value of the thermal compensation unit.

[0051] This embodiment utilizes a linear interpolation algorithm to achieve a rapid and accurate response to minute changes in the operating temperature of the OPA chip, improving the performance stability of the lidar under fluctuating temperature environments. By employing a first and a second temperature compensation table, combined with the linear interpolation algorithm, the optimal compensation parameters for each phase shifter and thermal compensation unit can be calculated based on the current operating temperature of the OPA chip, significantly improving calibration accuracy.

[0052] In one exemplary embodiment, the lidar includes a beam quality detection module, which includes a spot detector; the method further includes:

[0053] After phase adjustment using a first temperature compensation table and a second temperature compensation table, the target beam of the phase-adjusted OPA chip is acquired, wherein the target beam includes at least one of the following: a transmitted beam and a received beam; a beam distribution image of the target beam is acquired using a beam detector; beam-related information is extracted based on the beam distribution image, wherein the beam-related information includes at least one of the following: beam intensity distribution, beam shape, main lobe width, and side lobe level; the target beam is quality-assessed based on the beam-related information to obtain a beam quality assessment result; if the beam quality assessment result indicates that the beam quality of the target beam is lower than the preset quality requirement, phase adjustment is performed on each phase shifter according to a first phase adjustment step size, and temperature control is performed on the thermal compensation unit according to a first temperature adjustment step size, so that the phase of the optical antenna in the optical antenna unit is adjusted, and the phase-adjusted OPA chip is used to re-detect the target.

[0054] It should be noted that the lidar may include a beam quality detection module, which is a monitoring component used to detect and evaluate the beam quality generated by the OPA chip in real time, ensuring that the beam meets preset performance standards. This module includes a spot detector, which can detect the spot distribution of the beam in the far field, typically implemented using a high-sensitivity photodetector array. The spot detector is used to acquire images of the spot distribution after beam emission or reception.

[0055] The target beam can include at least one of the following: a transmitted beam and a received beam. The target beam is the object detected and evaluated by the beam quality detection module. Beam-related information may include, but is not limited to, the beam's intensity distribution, spot shape, main lobe width, and side lobe level, which can reflect the beam's quality characteristics and are an important basis for evaluating whether the beam meets the preset quality requirements.

[0056] Beam quality assessment results are quantitative, such as beam quality index or a judgment of whether it is qualified or not. Preset quality requirements can be defined beam quality standards used to determine whether the target beam meets the expected performance requirements. For example, the main lobe width cannot exceed a specific threshold, and the side lobe level must be below a certain limit, etc.

[0057] For example, after phase adjustment using a first temperature compensation table and a second temperature compensation table, the target beam generated by the OPA chip needs to be quality-tested and optimized. Specifically, after phase adjustment, the OPA chip emits or receives the target beam, and the spot detector in the beam quality detection module captures the far-field spot distribution image of the target beam to extract information such as beam intensity distribution, spot shape, main lobe width, and side lobe level. Based on the extracted beam-related information, the target beam is quality-assessed to obtain a beam quality assessment result. If the assessment result shows that the beam quality is lower than the preset quality requirement, phase adjustment is performed on each phase shifter according to the first phase adjustment step size to attempt to optimize the beam quality. Temperature control is performed on the thermal compensation unit according to the first temperature adjustment step size to locally adjust the temperature of the OPA chip to further improve the beam quality. After phase and temperature adjustments, the OPA chip re-emits the beam, and the beam quality detection module again captures the spot distribution image and performs a quality assessment. This process continues until the beam quality assessment result of the target beam meets the preset quality requirement. The first phase adjustment step size refers to the phase increment or decrement adjusted each time during phase correction, and is usually set according to system performance and calibration accuracy requirements. The first temperature adjustment step size refers to the temperature rise or fall range for each temperature adjustment, and is also determined based on system requirements and temperature response characteristics. Optionally, the sizes of the first phase adjustment step size and the first temperature adjustment step size can be obtained experimentally, and this application does not impose any limitations on them.

[0058] Through this embodiment, the real-time feedback of the beam quality detection module and the adaptive adjustment capability of the OPA chip can dynamically optimize the beam quality during operation, ensuring that a stable and high-quality laser detection capability can always be provided under different environmental conditions and temperatures. Furthermore, while maintaining high beam accuracy, it can improve the robustness and adaptability of the beam in complex environments, effectively avoiding beam quality degradation caused by temperature changes or other factors, and enhancing overall performance.

[0059] In one exemplary embodiment, the above method further includes:

[0060] When the target beam includes both a transmitting beam and a receiving beam, the spot overlap between the transmitting beam and the receiving beam in the target beam is determined based on beam-related information.

[0061] When the overlap of light spots is lower than the preset overlap, the phase of each phase shifter is adjusted according to the second phase adjustment step size, and the temperature of the thermal compensation unit is controlled according to the second temperature adjustment step size, so that the phase of the optical antenna in the optical antenna unit is adjusted, and the OPA chip with phase adjustment is used to re-detect the target.

[0062] The transmitted beam is a laser beam generated by the OPA chip for target detection. The received beam is the laser beam reflected or scattered from the target, used to analyze target characteristics such as range, velocity, and shape. The beam overlap ratio refers to the degree of overlap between the transmitted and received beams in the detection area. Generally, a high beam overlap ratio indicates good matching of the positions and shapes of the two beams. A preset overlap ratio is used to determine whether the beam overlap ratio meets the requirements for normal operation of the lidar. If the beam overlap ratio is lower than the preset overlap ratio, further phase and temperature adjustments are needed to optimize beam alignment and synchronization.

[0063] For example, an OPA chip is used to emit a beam to detect a target and simultaneously receive the reflected beam from the target. A beam quality detection module acquires beam distribution images of the emitted and received beams using a beam detector. Based on the acquired beam distribution images, the overlap between the emitted and received beams is calculated, which is the ratio of the overlapping area of ​​the two beams in space to the area of ​​the emitted beam. If the calculated overlap is lower than a preset overlap threshold, the phase of each phase shifter in the OPA chip is adjusted according to a second phase adjustment step size. Simultaneously, the temperature of the thermal compensation unit is controlled according to a second temperature adjustment step size. After phase and temperature adjustments, the OPA chip emits and receives beams again, recalculating the beam overlap until it meets the preset overlap requirement. The second phase adjustment step size is a phase fine-tuning amount set to optimize beam overlap, typically determined based on beam alignment accuracy and system response speed requirements. The second temperature adjustment step size refers to the amount of local temperature change adjusted to optimize beam overlap, used to improve the optical characteristics of the OPA chip and ensure precise alignment of the emitted and received beams. Optionally, the size of the second phase adjustment step and the second temperature adjustment step can be obtained experimentally, and this application does not limit it.

[0064] By ensuring that the overlap of the emitted and received beams reaches a preset standard, this embodiment enables more accurate target location and identification, thus improving the accuracy and reliability of detection.

[0065] In an exemplary embodiment, step S206 includes: using the phase-adjusted OPA chip to send a detection signal to the area where the detection target is located, and receiving the reflected signal reflected back by the detection target; performing beat frequency analysis on the local oscillator signal and the reflected signal corresponding to the detection signal to obtain a beat frequency signal; performing frequency analysis on the beat frequency signal, and determining the detection result of the detection target based on the analyzed signal frequency.

[0066] It should be noted that the detection signal can be a laser signal emitted by the OPA chip, used to detect information such as the target's distance, speed, and shape. After phase adjustment, the beam of the detection signal can be more accurately pointed at the target area. The reflected signal is the signal that is partially reflected or scattered back when the detection signal encounters the target. The reflected signal carries information about the target's position and properties. Beat frequency is a signal processing technique that mixes two signals of different frequencies to produce a signal with a frequency equal to the difference between the two signals. The local oscillator signal is a reference signal with a frequency close to that of the detection signal. By beating the reflected signal, the target information carried by the reflected signal can be converted into a beat frequency signal that is easy to process. The beat frequency signal is a signal generated through the beat frequency process, and its frequency is equal to the difference between the local oscillator frequency of the detection signal and the frequency of the reflected signal.

[0067] In this embodiment, by combining phase adjustment and beat frequency technology, the lidar can transmit and receive high-quality beam signals, thereby achieving high-precision target detection.

[0068] In one exemplary embodiment, the detection result includes at least one of the following: distance information, velocity information; frequency analysis of the beat frequency signal, and determination of the detection result of the target based on the analyzed signal frequency, including:

[0069] The beat frequency signal is digitized and modulated to obtain the round-trip time corresponding to the beat frequency signal; based on the round-trip time corresponding to the beat frequency signal, the distance information of the detected target is determined; and / or,

[0070] Doppler frequency analysis is performed on the beat frequency signal to obtain the Doppler frequency shift corresponding to the beat frequency signal; based on the Doppler frequency shift of the beat frequency signal, the velocity information of the target is determined.

[0071] Digital processing is the process of converting analog beat frequency signals into digital signals to facilitate subsequent signal processing and analysis. Digital processing typically includes steps such as sampling, quantization, and encoding. After digital processing, the signal is modulated to enhance its characteristics, facilitating the measurement of time delay or frequency. Modulation may include frequency modulation, phase modulation, or amplitude modulation.

[0072] The round-trip time can be defined as the time difference between transmitting the detection signal and receiving the reflected signal. Since the speed of light is constant, the round-trip time is proportional to the target distance; therefore, the target distance can be calculated by measuring the round-trip time.

[0073] When a target moves relative to the lidar, the frequency of the received reflected signal changes; this change is called the Doppler shift. The magnitude of the Doppler shift is proportional to the target's speed, therefore, the target's speed can be determined by analyzing the Doppler shift.

[0074] Specifically, the OPA chip emits a detection signal, which is reflected upon encountering the target, forming a reflected signal. This reflected signal is then beat-frequencyd with the local oscillator signal (a reference signal at a fixed frequency), generating a beat-frequency signal. This beat-frequency signal is first converted into a digital signal through digitization, and then modulated to enhance the waveform characteristics, facilitating subsequent time delay detection. Based on the modulated signal, its round-trip time (RTT), i.e., the time difference between the transmission of the detection signal and the reception of the reflected signal, is analyzed. The target's distance is obtained by multiplying the RTT by the speed of light and dividing by 2. The Doppler shift is determined by analyzing the frequency changes of the beat-frequency signal. By measuring the Doppler shift, the target's relative velocity can be calculated.

[0075] In this embodiment, by extracting the round-trip time through digital processing and modulation processing, and by determining the Doppler frequency shift through Doppler frequency analysis, the lidar can accurately obtain the target's distance and velocity information, thereby improving detection accuracy and reliability.

[0076] It should be noted that, for the sake of simplicity, the foregoing method embodiments are all described as a series of actions. However, those skilled in the art should understand that this application is not limited to the described order of actions, as some steps may be performed in other orders or simultaneously according to this application. Furthermore, those skilled in the art should also understand that the embodiments described in the specification are preferred embodiments, and the actions and modules involved are not necessarily essential to this application.

[0077] Through the above description of the embodiments, those skilled in the art can clearly understand that the methods according to the above embodiments can be implemented by means of software plus necessary general-purpose hardware platforms. Of course, they can also be implemented by hardware, but in many cases the former is a better implementation method. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product is stored in a storage medium (such as ROM (Read-Only Memory) / RAM (Random Access Memory), magnetic disk, optical disk), and includes several instructions to cause a terminal device (which may be a mobile phone, computer, server, or network device, etc.) to execute the methods described in the various embodiments of this application.

[0078] According to another aspect of the embodiments of this application, a target detection device based on lidar is also provided. The lidar includes an OPA chip, on which a temperature sensor, an optical antenna unit, and a thermal compensation unit for the optical antenna unit are disposed. The temperature sensor is used to detect the operating temperature of the OPA chip. This lidar-based target detection device can be used to implement the lidar-based target detection method provided in the above embodiments, and details already described will not be repeated. As used below, the term "module" can refer to a combination of software and / or hardware that performs a predetermined function. Although the device described in the following embodiments is preferably implemented in software, hardware implementation, or a combination of software and hardware, is also possible and contemplated.

[0079] Figure 4 This is a structural block diagram of an optional lidar-based target detection device according to an embodiment of this application, such as... Figure 4 As shown, the lidar-based target detection device includes:

[0080] The acquisition unit 402 is used to acquire the operating temperature of the OPA chip in real time through a temperature sensor when using LiDAR for detection.

[0081] The determining unit 404 is configured to, when the operating temperature of the OPA chip is detected to exceed a specified temperature range, determine the target phase correction parameter of each phase shifter in the OPA chip and the target temperature compensation value of the thermal compensation unit based on the latest detected operating temperature of the OPA chip, and perform phase adjustment on each phase shifter using the determined target phase correction parameter of each phase shifter, and perform temperature control on the optical antenna unit using the determined target temperature compensation value through the thermal compensation unit, so as to adjust the phase of the optical antenna in the optical antenna unit, wherein the specified temperature range is determined based on the operating temperature recorded during the last phase adjustment;

[0082] The detection unit 406 is used to detect the target using the phase-adjusted OPA chip and obtain the detection result of the target.

[0083] It should be noted that the acquisition unit 402 in this embodiment can be used to execute the above step S202, the determination unit 404 in this embodiment can be used to execute the above step S204, and the detection unit 406 in this embodiment can be used to execute the above step S206.

[0084] The embodiments provided in this application demonstrate that, when using a lidar for detection, the operating temperature of the OPA chip is acquired in real time via a temperature sensor. If the operating temperature of the OPA chip exceeds a specified temperature range, the target phase correction parameters for each phase shifter and the target temperature compensation value for the thermal compensation unit are determined based on the latest detected operating temperature of the OPA chip. This allows for phase adjustment of each phase shifter, and the determined target temperature compensation value is used by the thermal compensation unit to control the temperature of the optical antenna unit, thereby adjusting the phase of the optical antenna. The phase-adjusted OPA chip is then used to detect the target, yielding the detection result. This solves the problem in related technologies where temperature fluctuations cause changes in the refractive index of the phase modulator, resulting in low detection accuracy. Precise phase and temperature correction ensures accurate beam focusing and direction control, reducing errors during detection and improving the detection accuracy and reliability of the lidar. Furthermore, real-time temperature compensation and phase correction can adapt to a wider range of temperature changes, maintaining consistent detection performance of the lidar under different ambient temperatures.

[0085] In an exemplary embodiment, the lidar is provided with a first temperature compensation table and a second temperature compensation table, wherein the first temperature compensation table includes phase correction parameters of each phase shifter at each preset temperature in a set of preset temperatures, and the second temperature compensation table includes temperature compensation values ​​of the thermal compensation unit at each preset temperature in a set of preset temperatures.

[0086] The determining unit 404 is further configured to: search for a first target preset temperature that matches the latest operating temperature of the detected OPA chip from the first temperature compensation table; determine the phase correction parameters of each phase shifter under the first target preset temperature as the target phase correction parameters of each phase shifter; search for a second target preset temperature that matches the latest operating temperature of the detected OPA chip from the second temperature compensation table; and determine the temperature compensation value of the thermal compensation unit under the second target preset temperature as the target temperature compensation value of the thermal compensation unit.

[0087] In an exemplary embodiment, the lidar is provided with a first temperature compensation table and a second temperature compensation table, wherein the first temperature compensation table includes phase correction parameters of each phase shifter at each preset temperature in a set of preset temperatures, and the second temperature compensation table includes temperature compensation values ​​of the thermal compensation unit at each preset temperature in a set of preset temperatures.

[0088] The determining unit 404 is further configured to: based on the detected latest operating temperature of the OPA chip, look up a first preset temperature and a second preset temperature from a first temperature compensation table, wherein the first preset temperature and the second preset temperature are the two preset temperatures in the first temperature compensation table that are closest to the latest operating temperature of the OPA chip; determine the phase correction parameter of each phase shifter at the first preset temperature as a first phase correction value for each phase shifter, and determine the phase correction parameter of each phase shifter at the second preset temperature as a second phase correction value for each phase shifter, wherein the first preset temperature is less than the second preset temperature; and sum the result of multiplying the difference between the latest operating temperature of the OPA chip and the first preset temperature by a first specified coefficient corresponding to each phase shifter with the first phase correction value of each phase shifter to determine the target phase correction parameter for each phase shifter, wherein the first specified coefficient corresponding to each phase shifter is the second phase correction value of each phase shifter minus the first phase correction value of each phase shifter. The difference is obtained by dividing the difference between the second preset temperature and the first preset temperature; based on the latest operating temperature of the detected OPA chip, the third preset temperature and the fourth preset temperature are found in the second temperature compensation table, wherein the third preset temperature and the fourth preset temperature are the two preset temperatures in the second temperature compensation table that are closest to the latest operating temperature of the OPA chip; the temperature compensation value of the thermal compensation unit at the third preset temperature is determined as the first temperature correction value of the thermal compensation unit, and the temperature compensation value of the thermal compensation unit at the fourth preset temperature is determined as the second temperature correction value of the thermal compensation unit, wherein the third preset temperature is less than the fourth preset temperature; the result of multiplying the difference between the latest operating temperature of the OPA chip and the third preset temperature by a second specified coefficient and summing it with the first temperature correction value is used to determine the target temperature compensation value of the thermal compensation unit, wherein the second specified coefficient is obtained by dividing the difference between the second temperature correction value and the first temperature correction value by the difference between the fourth preset temperature and the third preset temperature.

[0089] In an exemplary embodiment, the lidar includes a beam quality detection module, which includes a spot detector; a target detection device based on the lidar includes: an adjustment unit, configured to: after phase adjustment using a first temperature compensation table and a second temperature compensation table, acquire a target beam from an OPA chip after phase adjustment, wherein the target beam includes at least one of the following: a transmitted beam and a received beam; acquire a spot distribution image of the target beam using the spot detector; extract beam-related information based on the spot distribution image, wherein the beam-related information includes at least one of the following: beam intensity distribution, spot shape, main lobe width, and side lobe level; perform a quality assessment of the target beam based on the beam-related information to obtain a beam quality assessment result; if the beam quality assessment result indicates that the beam quality of the target beam is lower than a preset quality requirement, perform phase adjustment on each phase shifter according to a first phase adjustment step size, and perform temperature control on the thermal compensation unit according to a first temperature adjustment step size, so that the phase of the optical antenna in the optical antenna unit is adjusted, and re-detect the target using the phase-adjusted OPA chip.

[0090] In an exemplary embodiment, the adjustment unit is further configured to: determine the spot overlap degree between the transmitted beam and the received beam in the target beam based on beam-related information when the target beam includes a transmitted beam and a received beam; adjust the phase of each phase shifter according to a second phase adjustment step size when the spot overlap degree is lower than a preset overlap degree; and control the temperature of the thermal compensation unit according to a second temperature adjustment step size so that the phase of the optical antenna in the optical antenna unit is adjusted, and re-detect the target using the phase-adjusted OPA chip.

[0091] In an exemplary embodiment, the detection unit 406 is further configured to: send a detection signal to the area where the detection target is located using the phase-adjusted OPA chip, and receive the reflected signal reflected back by the detection target;

[0092] Beat frequency signals are obtained by performing beat frequency analysis on the local oscillator signal and the reflected signal corresponding to the probe signal;

[0093] Frequency analysis is performed on the beat frequency signal, and the detection result of the target is determined based on the analyzed signal frequency.

[0094] In one exemplary embodiment, the detection result includes at least one of the following: distance information and velocity information;

[0095] The detection unit 406 is also used to: perform digital processing and modulation processing on the beat frequency signal to obtain the round-trip time corresponding to the beat frequency signal; and determine the distance information of the detection target based on the round-trip time corresponding to the beat frequency signal.

[0096] And / or, perform Doppler frequency analysis on the beat frequency signal to obtain the Doppler frequency shift corresponding to the beat frequency signal; based on the Doppler frequency shift of the beat frequency signal, determine the velocity information of the target being detected.

[0097] It should be noted that the above modules can be implemented by software or hardware. For the latter, they can be implemented in the following ways, but are not limited to: all the above modules are located in the same processor; or, the above modules are located in different processors in any combination.

[0098] According to another aspect of the embodiments of this application, a computer-readable storage medium is provided, the computer-readable storage medium including a stored program, wherein the program executes the steps in any of the above method embodiments when it is run.

[0099] In one exemplary embodiment, the aforementioned computer-readable storage medium may include, but is not limited to, various media capable of storing computer programs, such as USB flash drives, ROMs, RAMs, portable hard drives, magnetic disks, or optical disks.

[0100] According to another aspect of the embodiments of this application, an electronic device is provided, including a memory, a processor, and a computer program stored in the memory and executable on the processor. The processor is configured to perform the steps of any of the method embodiments described above via the computer program. In an exemplary embodiment, the electronic device may further include a transmission device and an input / output device, wherein the transmission device is connected to the processor, and the input / output device is connected to the processor.

[0101] Specific examples in this embodiment can be found in the examples described in the above embodiments and exemplary implementations, and will not be repeated here.

[0102] According to another aspect of the embodiments of this application, a computer program product is also provided, comprising a computer program / instructions containing program code for performing the methods shown in the flowchart. In such an embodiment, the computer program can be downloaded and installed from a network via communication section 509, and / or installed from removable medium 511. When the computer program is executed by central processing unit 501, it performs various functions provided in the embodiments of this application. The sequence numbers of the embodiments of this application above are merely descriptive and do not represent the superiority or inferiority of the embodiments.

[0103] Figure 5 A schematic block diagram of a computer system architecture for implementing embodiments of the present application is shown. Figure 5As shown, the computer system 500 includes a CPU (Central Processing Unit) 501, which can perform various appropriate actions and processes based on programs stored in ROM 502 or programs loaded into RAM 503 from storage section 508. Random access memory 503 also stores various programs and data required for system operation. The CPU 501, ROM 502, and RAM 503 are interconnected via bus 504. An I / O (Input / Output) interface 505 is also connected to bus 504.

[0104] The following components are connected to I / O interface 505: input section 506 including keyboard, mouse, etc.; output section 507 including CRT (Cathode Ray Tube), LCD (Liquid Crystal Display), etc., and speakers, etc.; storage section 508 including hard disk, etc.; and communication section 509 including network interface card, modem, etc. Communication section 509 performs communication processing via a network such as the Internet. Drive 510 is also connected to I / O interface 505 as needed. Removable media 511, such as disk, optical disk, magneto-optical disk, semiconductor memory, etc., are installed on drive 510 as needed so that computer programs read from them can be installed into storage section 508 as needed.

[0105] Specifically, according to embodiments of this application, the processes described in the various method flowcharts can be implemented as computer software programs. For example, embodiments of this application include a computer program product comprising a computer program carried on a computer-readable medium, the computer program containing program code for performing the methods shown in the flowcharts. In such embodiments, the computer program can be downloaded and installed from a network via communication section 509, and / or installed from removable medium 511. When the computer program is executed by central processing unit 501, it performs various functions defined in the system of this application.

[0106] It should be noted that, Figure 5 The computer system 500 of the electronic device shown is merely an example and should not impose any limitation on the functionality and scope of use of the embodiments of this application.

[0107] Obviously, those skilled in the art should understand that the modules or steps of this application described above can be implemented using general-purpose computing devices. They can be centralized on a single computing device or distributed across a network of multiple computing devices. They can be implemented using computer-executable program code, and thus can be stored in a storage device for execution by a computing device. In some cases, the steps shown or described can be performed in a different order than those presented here, or they can be fabricated as separate integrated circuit modules, or multiple modules or steps can be fabricated as a single integrated circuit module. Thus, this application is not limited to any particular combination of hardware and software.

[0108] The above are merely preferred embodiments of this application and are not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the principles of this application should be included within the protection scope of this application.

Claims

1. A target detection method based on lidar, characterized in that, The lidar includes an OPA chip, on which a temperature sensor, an optical antenna unit, and a thermal compensation unit are disposed. The temperature sensor is used to detect the operating temperature of the OPA chip. The method includes: When using the lidar for detection, the operating temperature of the OPA chip is obtained in real time through the temperature sensor. If the operating temperature of the OPA chip is detected to exceed the specified temperature range, the target phase correction parameter of each phase shifter in the OPA chip and the target temperature compensation value of the thermal compensation unit are determined based on the latest detected operating temperature of the OPA chip. The phase of each phase shifter is adjusted using the determined target phase correction parameter of each phase shifter. The temperature of the optical antenna unit is controlled by the thermal compensation unit using the determined target temperature compensation value, so that the phase of the optical antenna in the optical antenna unit is adjusted. The specified temperature range is determined based on the operating temperature recorded during the last phase adjustment. The OPA chip with phase adjustment is used to detect the target, and the detection result of the target is obtained.

2. The method according to claim 1, characterized in that, The lidar is equipped with a first temperature compensation table and a second temperature compensation table. The first temperature compensation table includes the phase correction parameters of each phase shifter at each preset temperature in a set of preset temperatures. The second temperature compensation table includes the temperature compensation value of the thermal compensation unit at each preset temperature in a set of preset temperatures. The step of determining the target phase correction parameter for each phase shifter in the OPA chip and the target temperature compensation value for the thermal compensation unit based on the detected latest operating temperature of the OPA chip includes: Find a first target preset temperature that matches the latest operating temperature of the detected OPA chip from the first temperature compensation table; The phase correction parameters of each phase shifter at the first target preset temperature are determined as the target phase correction parameters of each phase shifter; Find the second target preset temperature that matches the latest operating temperature of the detected OPA chip from the second temperature compensation table; The temperature compensation value of the thermal compensation unit at the second target preset temperature is determined as the target temperature compensation value of the thermal compensation unit.

3. The method according to claim 1, characterized in that, The lidar is equipped with a first temperature compensation table and a second temperature compensation table. The first temperature compensation table includes the phase correction parameters of each phase shifter at each preset temperature in a set of preset temperatures. The second temperature compensation table includes the temperature compensation value of the thermal compensation unit at each preset temperature in a set of preset temperatures. The step of determining the target phase correction parameter for each phase shifter in the OPA chip and the target temperature compensation value for the thermal compensation unit based on the detected latest operating temperature of the OPA chip includes: Based on the latest operating temperature of the detected OPA chip, a first preset temperature and a second preset temperature are found from the first temperature compensation table, wherein the first preset temperature and the second preset temperature are the two preset temperatures in the first temperature compensation table that are closest to the latest operating temperature of the OPA chip. The phase correction parameter of each phase shifter at the first preset temperature is determined as the first phase correction value of each phase shifter, and the phase correction parameter of each phase shifter at the second preset temperature is determined as the second phase correction value of each phase shifter, wherein the first preset temperature is less than the second preset temperature; The target phase correction parameter for each phase shifter is determined by multiplying the difference between the latest operating temperature of the OPA chip and the first preset temperature by a first specified coefficient corresponding to each phase shifter, and summing the result with the first phase correction value of each phase shifter. The first specified coefficient corresponding to each phase shifter is obtained by subtracting the difference between the second phase correction value and the first phase correction value of each phase shifter, and dividing the result by the difference between the second preset temperature and the first preset temperature. Based on the latest operating temperature of the detected OPA chip, the third preset temperature and the fourth preset temperature are found in the second temperature compensation table, wherein the third preset temperature and the fourth preset temperature are the two preset temperatures in the second temperature compensation table that are closest to the latest operating temperature of the OPA chip. The temperature compensation value of the thermal compensation unit at the third preset temperature is determined as the first temperature correction value of the thermal compensation unit, and the temperature compensation value of the thermal compensation unit at the fourth preset temperature is determined as the second temperature correction value of the thermal compensation unit, wherein the third preset temperature is less than the fourth preset temperature; The target temperature compensation value of the thermal compensation unit is determined by multiplying the difference between the latest operating temperature of the OPA chip and the third preset temperature by a second specified coefficient, and summing the result with the first temperature correction value. The second specified coefficient is obtained by dividing the difference between the second temperature correction value and the first temperature correction value by the difference between the fourth preset temperature and the third preset temperature.

4. The method according to claim 2 or 3, characterized in that, The lidar includes a beam quality detection module, which includes a spot detector; the method further includes: After phase adjustment using the first temperature compensation meter and the second temperature compensation meter, the target beam of the OPA chip after phase adjustment is obtained, wherein the target beam includes at least one of the following: a transmitted beam and a received beam; The spot distribution image of the target beam is obtained through the spot detector; Based on the light spot distribution image, beam-related information is extracted, wherein the beam-related information includes at least one of the following: beam intensity distribution, light spot shape, main lobe width, and side lobe level. Based on the beam-related information, the quality of the target beam is assessed to obtain the beam quality assessment result; If the beam quality assessment result indicates that the beam quality of the target beam is lower than the preset quality requirement, the phase of each phase shifter is adjusted according to the first phase adjustment step size, and the temperature of the thermal compensation unit is controlled according to the first temperature adjustment step size, so that the phase of the optical antenna in the optical antenna unit is adjusted, and the phase-adjusted OPA chip is used to re-detect the target.

5. The method according to claim 4, characterized in that, The method further includes: When the target beam includes a transmitting beam and a receiving beam, the spot overlap between the transmitting beam and the receiving beam in the target beam is determined based on the beam-related information. When the overlap of the light spots is lower than the preset overlap, the phase of each phase shifter is adjusted according to the second phase adjustment step size, and the temperature of the thermal compensation unit is controlled according to the second temperature adjustment step size, so that the phase of the optical antenna in the optical antenna unit is adjusted, and the OPA chip after phase adjustment is used to re-detect the detection target.

6. The method according to claim 1, characterized in that, The process of using the phase-adjusted OPA chip to detect the target and obtaining the detection result of the target includes: The phase-adjusted OPA chip sends a detection signal to the area where the detection target is located, and receives the reflected signal reflected back by the detection target; Beat frequency signals are obtained by performing beat frequency analysis on the local oscillator signal corresponding to the detection signal and the reflected signal; The beat frequency signal is analyzed for frequency, and the detection result of the target is determined based on the analyzed signal frequency.

7. The method according to claim 6, characterized in that, The detection results include at least one of the following: distance information, speed information; The step of performing frequency analysis on the beat frequency signal and determining the detection result of the target based on the analyzed signal frequency includes: The beat frequency signal is digitally processed and modulated to obtain the round-trip time corresponding to the beat frequency signal; Based on the round-trip time corresponding to the beat frequency signal, the distance information of the detected target is determined; And / or, Doppler frequency analysis is performed on the beat frequency signal to obtain the Doppler frequency shift corresponding to the beat frequency signal; The velocity information of the target is determined based on the Doppler frequency shift of the beat frequency signal.

8. A target detection device based on lidar, characterized in that, The lidar includes an OPA chip, on which a temperature sensor, an optical antenna unit, and a thermal compensation unit for the optical antenna unit are disposed. The temperature sensor is used to detect the operating temperature of the OPA chip. The device includes: The acquisition unit is used to acquire the operating temperature of the OPA chip in real time through the temperature sensor when the lidar is used for detection. A determining unit is configured to, when the operating temperature of the OPA chip is detected to exceed a specified temperature range, determine, based on the latest detected operating temperature of the OPA chip, a target phase correction parameter for each phase shifter in the OPA chip and a target temperature compensation value for the thermal compensation unit, and use the determined target phase correction parameters for each phase shifter to perform phase adjustment on each phase shifter. Furthermore, the thermal compensation unit uses the determined target temperature compensation value to perform temperature control on the optical antenna unit, thereby adjusting the phase of the optical antenna in the optical antenna unit. The specified temperature range is determined based on the operating temperature recorded during the last phase adjustment. The detection unit is used to detect the target using the phase-adjusted OPA chip and obtain the detection result of the target.

9. The apparatus according to claim 8, characterized in that, The lidar is equipped with a first temperature compensation table and a second temperature compensation table. The first temperature compensation table includes phase correction parameters for each phase shifter at each preset temperature in a set of preset temperatures. The second temperature compensation table includes temperature compensation values ​​for the thermal compensation unit at each preset temperature in a set of preset temperatures. The determining unit is further configured to: find a first target preset temperature in the first temperature compensation table that matches the latest detected operating temperature of the OPA chip; determine the phase correction parameters of each phase shifter at the first target preset temperature as the target phase correction parameters of each phase shifter; find a second target preset temperature in the second temperature compensation table that matches the latest detected operating temperature of the OPA chip; and determine the temperature compensation value of the thermal compensation unit at the second target preset temperature as the target temperature compensation value of the thermal compensation unit.

10. The apparatus according to claim 8, characterized in that, The lidar is equipped with a first temperature compensation table and a second temperature compensation table. The first temperature compensation table includes the phase correction parameters of each phase shifter at each preset temperature in a set of preset temperatures. The second temperature compensation table includes the temperature compensation value of the thermal compensation unit at each preset temperature in a set of preset temperatures. The determining unit is further configured to: search for a first preset temperature and a second preset temperature in the first temperature compensation table based on the detected latest operating temperature of the OPA chip, wherein the first preset temperature and the second preset temperature are the two preset temperatures in the first temperature compensation table that are closest to the latest operating temperature of the OPA chip; and set the phase correction parameters of each phase shifter at the first preset temperature. The first phase correction value for each phase shifter is determined, and the phase correction parameter of each phase shifter at the second preset temperature is determined as the second phase correction value for each phase shifter, wherein the first preset temperature is less than the second preset temperature; the difference between the latest operating temperature of the OPA chip and the first preset temperature is multiplied by a first specified coefficient corresponding to each phase shifter, and the result is summed with the first phase correction value of each phase shifter to determine the target phase correction parameter for each phase shifter, wherein the first specified coefficient corresponding to each phase shifter is obtained by subtracting the difference between the second phase correction value and the first phase correction value of each phase shifter, and dividing by the difference between the second preset temperature and the first preset temperature; Based on the detected latest operating temperature of the OPA chip, a third preset temperature and a fourth preset temperature are retrieved from the second temperature compensation table. The third and fourth preset temperatures are the two preset temperatures in the second temperature compensation table that are closest to the latest operating temperature of the OPA chip. The temperature compensation value of the thermal compensation unit at the third preset temperature is determined as the first temperature correction value of the thermal compensation unit, and the temperature compensation value of the thermal compensation unit at the fourth preset temperature is determined as the second temperature correction value of the thermal compensation unit. The third preset temperature is less than the fourth preset temperature. The difference between the latest operating temperature of the OPA chip and the third preset temperature is multiplied by a second specified coefficient, and the result is summed with the first temperature correction value to determine the target temperature compensation value of the thermal compensation unit. The second specified coefficient is obtained by subtracting the first temperature correction value from the second temperature correction value and dividing by the difference between the fourth and third preset temperatures.

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