A laser radar automatic control system, an automatic collimation method and a control method

Abstract

The application discloses a kind of laser radar automatic control system, automatic collimation method and control method, it is related to laser radar technical field.The system includes control computer, core control module and execution device group.Core control module includes frequency locking module, motor drive control module and meteorological monitoring module.Frequency locking module is used to collect spectrum signal and reference signal and extract frequency discrimination signal, to realize laser frequency closed loop locking.Automatic collimation module is used to control light beam adjustment mechanism scanning and adjusting position according to echo signal intensity until alignment.Meteorological monitoring module is used to determine operating condition according to environmental data and trigger protection action.The application aims to solve the problem of low efficiency and high artificial dependence of existing laser radar observation, realize the automation, remote and intelligent of observation process.

Description

Technical Field

[0001] This invention relates to the field of lidar technology, and in particular to an automatic lidar control system, an automatic collimation method, and a control method. Background Technology

[0002] As a high-precision remote sensing device, lidar has a complex system structure, encompassing multiple functional modules such as transmitters, receivers, data acquisition systems, and observation stations. The coordinated operation of these modules directly determines the observation accuracy and equipment safety.

[0003] In existing technologies, lidar observation stations typically rely on manual operation for power-on / off, status monitoring, and fault handling. This approach has several shortcomings in practical operation. On-duty personnel must determine whether powering on is suitable based on weather forecasts and on-site observations, lacking a comprehensive judgment mechanism that integrates local monitoring with cloud data. This leads to delays and misjudgments, reducing observation efficiency. Furthermore, the lidar system's sub-modules must be turned on or off sequentially according to a strict time sequence, resulting in cumbersome and inefficient procedures. Manual operation is prone to errors in sequence, creating equipment safety hazards and failing to meet the needs of unattended observation. In addition, the control software for each functional module is independent and lacks coordination, lacking a unified communication and control platform, hindering remote and automated management.

[0004] Therefore, how to overcome the limitations of manual operation and combine real-time meteorological monitoring and equipment status judgment to achieve fully automated operation and safety control of lidar has become an urgent technical problem to be solved. Summary of the Invention

[0005] The main objective of this invention is to provide an automatic control system, automatic collimation method, and control method for lidar, aiming to overcome the limitations of manual operation and achieve fully automated operation and safe control of lidar by combining real-time meteorological monitoring and equipment status judgment.

[0006] To achieve the above objectives, this invention proposes an automatic control system for lidar, comprising a control computer, a core control module, a multi-functional interface control module, and an execution device group. The control computer communicates with the core control module via a network interface to achieve human-machine interactive control and data management. The core control module is configured to coordinate the operation of the execution device group and includes: a motor drive control module for generating motion control signals to perform closed-loop control of the motors in the execution device group; a frequency locking module for acquiring spectral signals and reference signals from the lasers in the execution device group, extracting frequency discrimination signals, and generating feedback control signals to adjust the output frequency of the lasers; and a meteorological monitoring module for fusing local meteorological sensor data and network data. The system uses network weather forecast data and compares the fused data with preset weather thresholds. If the data does not meet the weather threshold requirements, a weather judgment result is generated to indicate the execution of protective actions. These protective actions include controlling the skylight to close, controlling the lens protective cover to close, or stopping the laser output. The multi-functional interface control module connects the core control module and the execution device group, and includes: an intelligent switch control module for controlling the power supply of the execution device group according to a preset timing sequence; an automatic collimation module for controlling the beam adjustment mechanism in the execution device group to perform scanning actions and adjusting the position according to the echo signal intensity until the emitted beam is aligned; and an intelligent protection control module for triggering the execution device group to perform protective actions based on the weather judgment result.

[0007] Preferably, the core control module is built on a field-programmable gate array (FPGA) board.

[0008] Preferably, the frequency locking module includes a signal acquisition unit, a phase-locked amplification and demodulation unit, and a feedback control unit; the signal acquisition unit is used to acquire the spectral signal through a first analog-to-digital conversion channel, and to acquire the signal to be demodulated and the reference signal through a second analog-to-digital conversion channel; the phase-locked amplification and demodulation unit is used to perform frequency mixing and filtering on the signal to be demodulated and the reference signal to extract the frequency discrimination signal containing amplitude information; the feedback control unit is used to generate the feedback control signal based on the frequency discrimination signal using a PID algorithm and output it to the frequency adjustment device of the laser.

[0009] Preferably, the frequency locking module is further configured to provide multiple reference signal modes, including: an external reference mode: directly using an external signal acquired by the signal acquisition unit as the reference signal; and an internal reference mode: using an internally integrated direct digital frequency synthesis unit to generate a cosine signal as the reference signal, and simultaneously generating a sine signal for modulating the optical path.

[0010] Preferably, the frequency locking module is further configured to perform phase shifting processing on the reference signal; in the external reference mode, phase shifting is achieved by combining a first-in-first-out queue with an interpolation algorithm; in the internal reference mode, phase shifting is achieved by adjusting the initial phase address of the waveform data read by the direct digital frequency synthesis unit.

[0011] Preferably, the automatic collimation module is configured to: if no valid echo signal is detected at the initial scanning position, control the beam adjustment mechanism to perform a spiral search scan; if a valid echo signal is detected, control the beam adjustment mechanism to perform a single-axis scan or a two-dimensional matrix scan, and dynamically adjust the moving direction and moving step size according to the change in the echo signal intensity.

[0012] Preferably, the intelligent switch control module includes a power sequencer and a switch actuator group; the intelligent switch control module is configured to receive power on / off commands and sequentially turn on or off the power of each device in the actuator group according to a preset device priority sequence.

[0013] Preferably, the system further includes a multi-channel serial port management module, used to convert devices with serial communication interfaces in the execution device group into Ethernet interfaces, and uniformly connect them to the control computer for centralized management.

[0014] This application also discloses an automatic collimation method for lidar applied to the system described above. The method is executed by the automatic collimation module and includes the following steps: reading the motor position stored at the end of the previous observation as the initial scanning position for this collimation; determining whether a valid echo signal exists at the initial scanning position; if no valid echo signal is detected, controlling the beam adjustment mechanism to perform a spiral search scan centered on the initial scanning position; if a valid echo signal is detected, performing a single-axis scan or a two-dimensional matrix scan; during the scan, an adaptive algorithm dynamically adjusts the moving direction and step size of the beam adjustment mechanism according to changes in the echo signal intensity until the signal intensity reaches its peak and the optimal emitted beam direction is locked.

[0015] This application also discloses an automatic control method for lidar, characterized in that it is applied to the system described in any of the preceding claims. The method includes the following steps: a meteorological monitoring module acquires current environmental data and meteorological forecast data, and determines whether preset start-up meteorological conditions are met; when the start-up meteorological conditions are met, an intelligent switch control module controls the startup of each subsystem of the lidar according to a preset timing sequence, wherein the auxiliary cooling equipment is turned on first; a frequency locking module collects spectral signals and reference signals, extracts frequency discrimination signals using phase-sensitive detection technology, and performs closed-loop feedback adjustment of the laser frequency; an automatic collimation module searches for and locks the optimal emission beam direction using the automatic collimation method described above; during the observation process, the environmental data is continuously monitored, and when the operating conditions are not met, the intelligent protection control module triggers a protection action.

[0016] The above technical solution has the following advantages:

[0017] This invention achieves automation and intelligence in the lidar observation process through the coordinated control of the execution equipment group by the core control module. The frequency locking module employs a closed-loop feedback mechanism, which can adjust the laser output frequency in real time based on the frequency discrimination signal, ensuring long-term stable locking of the laser frequency and effectively improving the accuracy of the observation data. The automatic collimation module achieves automatic optimization and alignment of the emitted beam through scanning control of the beam adjustment mechanism and feedback adjustment of the echo signal, solving the problems of time-consuming, labor-intensive, and inaccurate traditional manual adjustment. The meteorological monitoring module can sense environmental data in real time and make comprehensive judgments based on forecast information. It automatically triggers protective actions when operating conditions are not met, effectively avoiding damage to precision instruments caused by severe weather. Therefore, while ensuring the safe and stable operation of the equipment, it significantly improves the observation efficiency and unattended operation capability of the lidar. Attached Figure Description

[0018] The present invention will now be described in detail with reference to specific embodiments and accompanying drawings, wherein:

[0019] Figure 1 This is a schematic diagram of the overall structure of the lidar automatic control system provided in an embodiment of the present invention.

[0020] Figure 2 This is a block diagram of the internal structure of the core control module provided in an embodiment of the present invention.

[0021] Figure 3 This is a schematic diagram illustrating the working principle of the frequency locking module provided in an embodiment of the present invention.

[0022] Figure 4 This is a schematic diagram of the functional unit structure of the automatic collimation module provided in an embodiment of the present invention. Detailed Implementation

[0023] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the following specific embodiments are only used to explain the invention and do not constitute a limitation thereof.

[0024] Example 1

[0025] like Figure 1 As shown, this embodiment provides an automatic control system for lidar. The system adopts a hierarchical and modular design concept, constructing a four-level control architecture to achieve fully automated and intelligent control of the lidar system. The system mainly includes a control computer 101, a core control module 201, a multi-functional interface control module 301, and a group of execution devices.

[0026] The control computer 101 serves as the management and interaction core of the system, equipped with human-machine interface control software. The control computer 101 establishes a communication connection with an external network server 102 via a network interface. The control computer 101 possesses operation control, data interaction, and interface display functions. The operation control function enables one-button power on / off of the lidar system, real-time monitoring of the status of each functional module, and fault detection and handling. The data interaction function establishes communication with an external meteorological website server via the network interface to acquire meteorological data and short-term forecast data in real time, while simultaneously uploading lidar observation data to the network server 102, supporting data storage and remote access. The interface display function provides a modular interactive interface, including an equipment control interface, an observation management interface, a meteorological monitoring interface, and a fault alarm interface. The equipment control interface is used to start / stop and adjust parameters of equipment such as the laser and water chiller. The observation management interface displays the spectral signal and real-time echo signal curve when the laser frequency is locked. The meteorological monitoring interface displays local and cloud-based meteorological data and trend curves and provides early warning prompts. The fault alarm interface provides real-time alerts for equipment malfunctions and generates operation logs.

[0027] The core control module 201 is the central control hub of the entire lidar system. Built on an FPGA board, it is directly connected to the control computer 101 via a high-speed bus interface. This core control module 201 integrates multiple key functions, possessing high real-time performance and parallel processing capabilities, and is used to coordinate the operation of various actuators. For example... Figure 2 As shown, the core control module 201 mainly includes a frequency locking module 202, a motor drive control module 203, and a meteorological monitoring module 204.

[0028] The frequency locking module 202 is configured to acquire the spectral signal and reference signal of the laser in the execution device group, demodulate the acquired signal to extract the frequency discrimination signal, and generate a feedback control signal based on the frequency discrimination signal to adjust the output frequency of the laser, thereby achieving closed-loop locking of the laser frequency. Figure 3As shown, the frequency locking module 202 specifically includes a signal acquisition unit 2021, a phase-locked amplifier demodulation unit 2022, and a PID feedback control unit 2023. The signal acquisition unit 2021 employs multi-channel synchronous acquisition technology, acquiring the spectral signal in the frequency-locked optical path through the first analog-to-digital conversion channel (ADC1) at a sampling rate of 200 KSPS. The signal acquisition unit 2021 acquires the demodulated signal and reference signal input to the phase-locked amplifier module through the second analog-to-digital conversion channel (ADC2) at a sampling rate of 125 MSPS, both with a resolution of 16 bits. The phase-locked amplifier demodulation unit 2022 is used to mix and filter the demodulated signal and the reference signal. Specifically, a multiplier multiplies the demodulated signal and the reference signal to obtain a mixed signal consisting of a superposition of a harmonic signal and a difference frequency signal; a low-pass filter filters the mixed signal output by the multiplier, removing the harmonic signal and using phase-sensitive detection technology to extract the frequency discrimination signal containing amplitude information, i.e., the DC component. The PID feedback control unit 2023 generates a feedback control signal, i.e., a control voltage, based on the frequency discrimination signal using a PID algorithm, and outputs it to the frequency adjustment device of the laser, i.e., the piezoelectric ceramic PZT. Closed-loop locking control of the laser output frequency is achieved by adjusting the PZT voltage. Furthermore, the frequency locking module 202 also includes a second selector, which outputs different voltage control signals to the digital-to-analog converter (DAC) according to the operating stage of the frequency locking module; during the frequency sweep stage, it outputs a triangular wave frequency sweep signal; during the frequency locking stage, it outputs a control signal that has been amplified, demodulated, and adjusted by feedback.

[0029] Furthermore, the frequency locking module 202 is configured to provide multiple reference signal modes, including an external reference mode and an internal reference mode. In the external reference mode, the external signal acquired by the signal acquisition unit 2021 is directly used as the reference signal. In the internal reference mode, a cosine signal is generated as the reference signal using the internally integrated direct digital frequency synthesis unit (DDS module), and a sine signal is simultaneously generated for modulation of the optical path. The frequency locking module 202 is also configured to perform phase shifting processing on the reference signal. In the external reference mode, phase shifting is achieved through a first-in-first-out (FIFO) queue combined with an interpolation algorithm, with FIFO achieving phase shifting of an integer number of sampling points and an interpolator achieving phase shifting of sub-sampling points. In the internal reference mode, phase shifting is directly achieved by adjusting the initial phase address of the waveform data read by the direct digital frequency synthesis unit. The DDS module, based on digital frequency synthesis technology, generates frequency-adjustable sine and cosine signals and triangular wave sweep signals by reading waveform data from the ROM, achieving a frequency resolution of up to 0.1 Hz. The triangular wave signal is used to perform a wide-range frequency scan of the PZT laser to determine the approximate frequency locking range.

[0030] The motor drive control module 203 is used to distribute control commands to the servo motors and actuators, and to collect and adjust the operating status of the motors and actuators in real time to achieve closed-loop control. Its controlled objects include the actuator motors for the switches of various devices in the laser, water chiller, and other actuator groups; the beam collimation control motor group of the automatic collimation module; and the drive motors for the sunroof and lens protection devices. The motor drive control module 203 includes a control command distribution unit 2031, a status monitoring unit 2032, and a feedback adjustment unit 2033.

[0031] The meteorological monitoring module 204 acquires current environmental data and determines whether operating conditions are met based on this data. If operating conditions are not met, the execution equipment group is triggered to perform protective actions. The meteorological monitoring module 204 includes a local meteorological sensor array (i.e., sensor data processing unit 2041), a cloud data interface, and an intelligent judgment unit 2042. The local meteorological sensor array collects real-time environmental data such as cloud cover, ambient brightness, rainfall, temperature, and humidity at the lidar observation site. The cloud data interface accesses an external meteorological website server via the network to obtain short-term weather forecast information for the observation site. The intelligent judgment unit 2042 integrates real-time monitoring data from the local meteorological sensors and meteorological forecast data obtained through the network interface to comprehensively determine operating conditions.

[0032] The multi-functional interface control module 301 connects the core control module 201 and the execution device group for functional expansion. The multi-functional interface control module 301 includes a multi-channel serial port management module 302, an intelligent switch control module 303, an automatic alignment module 304, and an intelligent protection control module 305.

[0033] The multi-channel serial port management module 302 is used to convert devices with serial communication interfaces in the execution device group into Ethernet interfaces and centrally manage them by connecting them to the control computer 101. This module is built on a serial port server and enables the access of multiple RS232 or RS485 interface devices, alleviating the interface resource pressure on the FPGA core control module.

[0034] The intelligent switch control module 303 is configured to receive power on / off commands and, according to a preset device priority sequence, sequentially turn on or off the power to each device in the device group. The sequence is configured to prioritize turning on the auxiliary cooling device during startup and delay turning it off during shutdown. This module uses a power sequencer as its core component and works in conjunction with the switch actuator group.

[0035] The automatic collimation module 304 controls the beam adjustment mechanism, i.e., the two-dimensional adjustment lens 406, in the execution device group to perform the scanning action, and adjusts the position of the beam adjustment mechanism according to the changes in echo signal intensity detected during the scanning process until the emitted beam is aligned. Figure 4As shown, the automatic collimation module 304 includes an automatic initialization and storage unit 3041, an automatic collimation mode determination unit 3042, and an adaptive adjustment unit 3043. This module is configured to perform scanning operations as follows: First, it acquires the stored historical collimation position as the initial scanning position. If no valid echo signal is detected at the initial scanning position, it controls the beam adjustment mechanism to perform a spiral search scan centered on the initial scanning position. If a valid echo signal is detected, it performs a single-axis scan or a two-dimensional matrix scan, and the adaptive adjustment unit 3043 dynamically adjusts the movement step size and direction of the beam adjustment mechanism according to changes in the echo signal intensity.

[0036] The intelligent protection control module 305 is linked with the skylight 407 and the lens protective cover 408 to receive real-time data from the local meteorological sensor array and execute protective actions based on the judgment results of the meteorological monitoring module 204. The protective actions include at least controlling the skylight 407 in the execution equipment group to close, controlling the lens protective cover 408 to close, or stopping the laser output.

[0037] The execution equipment group serves as the functional execution carrier of the lidar system, corresponding to the various functional modules of the multi-functional interface control module 301. The execution equipment group includes a laser controller 401, a water chiller 402, a frequency monitoring system 403, a photomultiplier tube 404, a photon counter 405, a two-dimensional adjustment frame 406, a skylight 407, and a lens protective cover 408. The laser controller 401, water chiller 402, frequency monitoring system 403, photomultiplier tube 404, and photon counter 405 are controlled by a multi-channel serial port management module 302 and an intelligent switch control module 303. The two-dimensional adjustment frame 406 is controlled by an automatic collimation module 304. The skylight 407 and lens protective cover 408 are controlled by an intelligent protection control module 305.

[0038] Example 2

[0039] This embodiment provides an automatic control method for lidar, which is applied to the lidar automatic control system described in Embodiment 1. This control method aims to achieve unattended automated operation of the lidar observation process, mainly including steps such as meteorological condition judgment, system equipment timing startup, laser frequency locking and beam collimation, observation data acquisition and labeling, operation monitoring and anomaly handling, and system equipment timing shutdown. The meteorological condition judgment step is executed first.

[0040] The intelligent judgment unit 2042 of the meteorological monitoring module 204 integrates real-time data collected by the local meteorological sensor array with forecast data obtained from the cloud data interface to comprehensively judge the lidar observation environment. Specifically, the system sets thresholds for key parameters such as cloud cover, ambient brightness, and rainfall. If all parameters meet the threshold requirements, the intelligent judgment unit 2042 generates a power-on signal. If any parameter fails to meet the threshold requirements, such as detecting rainfall or excessively high cloud cover, the system will enter a waiting state and periodically repeat the judgment process after a preset delay until the meteorological conditions meet the requirements.

[0041] After the meteorological conditions are met, the system equipment begins its sequential startup process. The intelligent switch control module 303 controls the power sequencer to turn on the system power supply step by step according to the preset power supply sequence. This sequence is configured to prioritize the activation of auxiliary cooling equipment during startup, that is, to first power the water chiller 402 to ensure that the cooling system operates first. After a certain delay, power is then supplied to the core equipment, including the laser controller 401 and the frequency monitoring system 403. Finally, power is supplied to the photomultiplier tube 404 and the photon counter 405 data acquisition equipment. Simultaneously, the intelligent switch control module 303 drives the mechanical switches of each device through the switch actuator group to achieve safe startup of the entire system.

[0042] Subsequently, laser frequency locking and beam collimation steps are performed. Frequency locking module 202 is activated, and signal acquisition unit 2021 acquires the spectral signal and the signal to be demodulated. Phase-locked amplification and demodulation unit 2022 extracts the frequency discrimination signal using phase-sensitive detection. PID feedback control unit 2023 generates a control voltage based on the frequency discrimination signal and outputs it to the piezoelectric ceramic PZT of the laser, achieving closed-loop locking of the laser frequency. Simultaneously, automatic collimation module 304 controls the two-dimensional adjustment lens 406 to scan, automatically searching for and locking the optimal emitted beam direction based on changes in echo signal intensity.

[0043] Next, the observation data acquisition and annotation steps begin. The human-machine interface control software of the control computer 101 issues data acquisition commands. The photomultiplier tube 404 receives the laser echo signal, and the photon counter 405 acquires the signal. The control computer 101, in conjunction with current meteorological data and equipment status, annotates the acquired signal in real time. The annotation content includes acquisition time, echo signal strength, weather conditions, and equipment operating status. The acquired data is stored in real time on the control computer 101 and uploaded to the network server 102.

[0044] During the observation process, continuous operation monitoring and anomaly handling procedures are implemented. The core control module 201 collects the operating parameters of each module in real time, including laser frequency, motor position, water chiller temperature, and meteorological data. If an abnormal parameter is detected, such as laser lockout, motor malfunction, or meteorological parameters exceeding the threshold, the system automatically records the anomaly log and triggers an alarm. If a serious anomaly is determined, such as detected rainfall or critical equipment failure, the intelligent protection control module 305 automatically executes protective actions, including closing the skylight 407, stopping laser output, and closing the lens protective cover 408.

[0045] Finally, when the observation mission ends or a shutdown command is received, the system equipment timing shutdown procedure is executed. The intelligent switch control module 303 controls the power sequencer to shut down the power to each device in the reverse order of power supply, that is, first shutting down the laser and data acquisition equipment, and finally shutting down the water chiller 402 to ensure that the laser is adequately cooled. During the shutdown process, the system records the operation logs of each device and completes data storage and uploading.

[0046] Example 3

[0047] This embodiment provides a detailed description of the automatic collimation steps in Embodiment 2. Automatic collimation is a crucial step in ensuring the detection efficiency of the lidar, and it is accomplished by the automatic collimation module 304 in conjunction with the motor drive control module 203 and the two-dimensional adjustment frame 406.

[0048] The automatic alignment process includes the following steps: First, the automatic initialization and storage unit 3041 reads the motor position data stored at the end of the previous observation and uses this data as the reference point for this alignment, i.e., the initial scanning position. This method can quickly locate the position using historical data, significantly shortening the search time.

[0049] Next, the system determines whether a valid echo signal exists at the reference point. If no echo signal is detected at the initial position, the collimation mode automatic judgment unit 3042 controls the two-dimensional adjustment frame 406 to perform a spiral scanning motion centered on the reference point. The spiral scan can cover a large search range and is suitable for situations where the initial deviation is large, resulting in signal loss. If an echo signal is detected at the initial position, or if a signal is captured during the spiral scan, the control system switches to a single-axis scan or two-dimensional matrix scan mode to perform a local fine scan to accurately locate the point of strongest signal.

[0050] During the aforementioned scanning process, the adaptive adjustment unit 3043 employs an adaptive algorithm for dynamic adjustment. Specifically, the system adjusts the scanning step size based on changes in the echo signal intensity. When the signal intensity increases rapidly, a larger step size is used to quickly approach the peak value.

[0051] When the signal strength approaches its peak and the signal enhancement amplitude decreases, the step size is automatically reduced to improve positioning accuracy. The system continuously monitors signal changes until the signal strength reaches its peak. Once the optimal position of the echo signal is found, the beam collimation is considered complete. At this point, the automatic initialization and storage unit 3041 stores the current motor position coordinates as a new reference point for rapid collimation initialization in the next observation experiment.

[0052] Example 4

[0053] This embodiment provides a detailed description of the phase-shifting processing of the frequency locking module 202 in Embodiment 1. In the laser frequency locking process, accurate phase matching is crucial for extracting a high-quality frequency discrimination signal. The frequency locking module 202 employs differentiated phase-shifting strategies based on the different sources of the reference signal.

[0054] When the system operates in external reference mode, the signal acquisition unit 2021 acquires an external reference signal. At this time, the frequency locking module 202 implements phase shifting using a first-in-first-out (FIFO) queue combined with an interpolation algorithm. Specifically, it uses the read / write pointer offset of the FIFO to achieve coarse phase shifting of an integer number of sampling points, and then uses a digital interpolation filter to calculate the values ​​between the sampling points, achieving fine phase shifting at the sub-sampling point level. This method enables high-precision phase adjustment of the externally input analog reference signal.

[0055] When the system operates in internal reference mode, a reference signal is generated using the internally integrated Direct Digital Synthesis (DDS) module. In this mode, phase shifting is performed directly within the DDS module. Specifically, the phase of the output signal is directly changed by adjusting the initial phase address of the waveform data read from the read-only memory (ROM) by the DDS module. For example, by increasing or decreasing the initial value of the phase accumulator, a cosine signal with a specific phase shift is directly generated as the reference signal. This method eliminates the need for additional filtering and offers higher phase control accuracy and stability. Simultaneously, the DDS module synchronously generates a sine signal to drive the acousto-optic modulator (AOM) to modulate the optical path, ensuring strict frequency synchronization and phase control between the modulated signal and the demodulated reference signal.

[0056] It will be readily understood by those skilled in the art that the above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. An automatic control system for lidar, characterized in that, The system includes a control computer, a core control module, a multi-functional interface control module, and an execution device group; the control computer is used to communicate with the core control module through a network interface to realize human-computer interaction control and data management. The core control module, configured to coordinate the operation of the execution device group, includes: a motor drive control module for generating motion control signals to perform closed-loop control of the motors in the execution device group; and a frequency locking module for acquiring the spectral signal and reference signal of the laser in the execution device group, extracting the frequency discrimination signal, and generating a feedback control signal to adjust the output frequency of the laser. The frequency locking module includes a signal acquisition unit, a lock-in amplifier / demodulation unit, and a feedback control unit. The signal acquisition unit acquires the spectral signal through a first analog-to-digital conversion channel and acquires the demodulated signal and the reference signal through a second analog-to-digital conversion channel. The lock-in amplifier / demodulation unit mixes and filters the demodulated signal and the reference signal to extract the frequency discrimination signal containing amplitude information. The feedback control unit, based on the frequency discrimination signal, uses a PID controller to adjust the output frequency of the laser. The algorithm generates the feedback control signal and outputs it to the frequency adjustment device of the laser; and the frequency locking module is configured to provide multiple reference signal modes, including: an external reference mode, which directly uses the external signal acquired by the signal acquisition unit as the reference signal; an internal reference mode, which uses the internally integrated direct digital frequency synthesis unit to generate a cosine signal as the reference signal, and synchronously generates a sine signal for modulation of the optical path; the frequency locking module is also configured to perform phase shifting processing on the reference signal: in the external reference mode, phase shifting is achieved by combining a first-in-first-out queue with an interpolation algorithm; in the internal reference mode, phase shifting is achieved by adjusting the initial phase address of the waveform data read by the direct digital frequency synthesis unit; a meteorological monitoring module is used to fuse local meteorological sensor data and network meteorological forecast data, and compare the fused data with a preset meteorological threshold. If the data does not meet the meteorological threshold requirements, a meteorological judgment result indicating the execution of protective actions is generated. The protective actions include controlling the skylight to close, controlling the lens protective cover to close, or stopping the laser output; the multi-functional interface control module connects the core control module and the execution device group, including: An intelligent switch control module is used to control the power supply start-up and shutdown of the execution device group according to a preset timing sequence. The intelligent switch control module includes a power sequencer and a switch actuator group, configured to receive power-on / off commands and sequentially turn on or off the power supply of each device in the execution device group according to a preset device priority timing sequence. The preset device priority timing sequence is configured as follows: when starting up, the auxiliary cooling device is turned on first, and the laser controller is powered on after a preset delay; when stopping, the laser controller is turned off first, and the auxiliary cooling device is turned off after a preset delay to ensure that the laser is sufficiently cooled. An automatic collimation module is used to control the beam adjustment mechanism in the execution device group to perform scanning actions and adjust the position according to the echo signal intensity until the emitted beam is aligned.The intelligent protection control module is used to trigger the actuator group to perform protection actions based on the meteorological judgment result.

2. The automatic control system for lidar according to claim 1, characterized in that, The core control module is built on a field-programmable gate array (FPGA) board.

3. The automatic control system for lidar according to claim 1, characterized in that, The automatic collimation module is configured to: if no valid echo signal is detected at the initial scanning position, control the beam adjustment mechanism to perform a spiral search scan; if a valid echo signal is detected, control the beam adjustment mechanism to perform a single-axis scan or a two-dimensional matrix scan, and dynamically adjust the moving direction and moving step size according to the change in the echo signal intensity.

4. The automatic control system for lidar according to claim 1, characterized in that, The system also includes a multi-channel serial port management module, which converts devices with serial communication interfaces in the execution device group into Ethernet interfaces and connects them to the control computer for centralized management.

5. A method for automatic collimation of a lidar applied to the system as described in claim 1, characterized in that, The method is executed by the automatic collimation module and includes the following steps: reading the motor position stored at the end of the previous observation as the initial scanning position for this collimation; determining whether there is a valid echo signal at the initial scanning position; if no valid echo signal is detected, controlling the beam adjustment mechanism to perform a spiral search scan centered on the initial scanning position; if a valid echo signal is detected, performing a single-axis scan or a two-dimensional matrix scan; during the scanning process, an adaptive algorithm is used to dynamically adjust the moving direction and moving step size of the beam adjustment mechanism according to the changes in the echo signal intensity until the signal intensity reaches its peak and the optimal transmitted beam direction is locked.

6. An automatic control method for lidar, characterized in that, Applied to the system as described in any one of claims 1-4, the method includes the following steps: a meteorological monitoring module acquires current environmental data and meteorological forecast data, and determines whether preset start-up meteorological conditions are met; when the start-up meteorological conditions are met, an intelligent switch control module controls the startup of each subsystem of the lidar according to a preset timing sequence, wherein the auxiliary cooling equipment is turned on first; a frequency locking module acquires spectral signals and reference signals, extracts frequency discrimination signals using phase-sensitive detection technology, and performs closed-loop feedback adjustment of the laser frequency; an automatic collimation module searches for and locks the optimal emitted beam direction using the automatic collimation method described in claim 5; during the observation process, the environmental data is continuously monitored, and when the operating conditions are not met, the intelligent protection control module triggers a protection action.

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