High-altitude equipment surface detection system and method based on three-axis truss mechanism and solid-state laser radar

Abstract

The invention discloses a high-altitude equipment surface detection system and method based on a three-axis truss mechanism and a solid-state laser radar, and relates to the technical field of high-altitude equipment detection.The external assembly in the system comprises the solid-state laser radar, an inertial measurement unit, an encoder assembly, a pressure sensor, a stepping motor and a micro water pump; the adjusting mechanism comprises a three-axis truss mechanism and an end effector which is mounted at the tail end of the adjusting mechanism and is integrated with at least one surface detection device; the control unit comprises a main control unit, a signal processing unit, a communication interface unit and a motor driving unit; the main control unit is composed of a single-chip microcomputer MCU and a peripheral circuit. The signal processing unit is used for processing data detected by the pressure sensor and the encoder assembly and sending the processed data to the main control unit; the unmanned aerial vehicle platform is connected with the three-axis truss mechanism through a support. The system can accurately and stably detect the surface of the high-altitude equipment.

Description

Technical Field

[0001] This application relates to the field of high-altitude equipment inspection technology, and in particular to a high-altitude equipment surface inspection system and method based on a three-axis truss mechanism and a solid-state lidar. Background Technology

[0002] Traditional high-altitude equipment inspection mainly relies on manual climbing or fixed inspection platforms. This method has the problems of low efficiency and high risk of manual inspection. At the same time, fixed inspection platforms cannot adapt to irregular surfaces, while drone inspection is affected by attitude changes and equipment shaking, making it difficult for the inspection device to be accurately positioned. Furthermore, existing inspection systems generally lack real-time position feedback and compensation mechanisms, making it impossible to accurately and stably inspect the surface of high-altitude equipment. Summary of the Invention

[0003] The purpose of this application is to provide a surface inspection system and method for high-altitude equipment based on a three-axis truss mechanism and solid-state lidar, which can accurately and stably inspect the surface of high-altitude equipment.

[0004] To achieve the above objectives, this application provides the following solution: In a first aspect, this application provides a surface inspection system for high-altitude equipment based on a three-axis truss mechanism and a solid-state lidar, comprising: External components include solid-state lidar, inertial measurement unit, encoder assembly, pressure sensor, stepper motor and miniature water pump.

[0005] The adjustment mechanism includes a three-axis truss mechanism and an end effector mounted at the end of the adjustment mechanism and integrating at least one surface detection device.

[0006] The control unit includes a main control unit, a signal processing unit, a communication interface unit, and a motor drive unit. The main control unit consists of a microcontroller (MCU) and peripheral circuits. The peripheral circuits include an external power supply filter circuit, a download circuit, and an interface protection circuit. The signal processing unit processes the data detected by the pressure sensor and encoder assembly and sends the processed data to the main control unit. The communication interface unit is connected to the inertial measurement unit and the solid-state lidar signal. The motor drive unit receives commands from the main control unit and drives the stepper motor and the micro water pump.

[0007] The drone platform is connected to the three-axis truss mechanism via a bracket.

[0008] Optionally, the solid-state lidar is used to acquire three-dimensional point cloud data of the surface of the high-altitude equipment; the inertial measurement unit is used to measure the current pose data of the end effector; the encoder assembly is used to sense the speed and angle information of the stepper motor and the magnetic powder spraying flow rate information of the micro water pump, and feeds back the speed and angle information and the magnetic powder spraying flow rate information to the main control unit; the pressure sensor is used to sense the positioning status of the end effector; the stepper motor is used to drive the three-axis truss mechanism to perform displacement actions; the micro water pump is used to spray magnetic suspension liquid during magnetic powder detection; and the pressure sensor is used to detect the contact force between the end effector and the surface of the high-altitude equipment.

[0009] Optionally, the control unit also includes a power supply system.

[0010] Optionally, the three-axis truss mechanism includes three linear motion modules orthogonally arranged in three-dimensional space. Each linear motion module is driven by a stepper motor and converts rotational motion into linear motion through a ball screw.

[0011] Optionally, the surface inspection device includes an electromagnetic ultrasonic thickness measuring device and a magnetic particle flaw detection device.

[0012] Optionally, the motor drive unit includes a stepper motor drive subunit and a micro water pump drive subunit.

[0013] The stepper motor driver unit is composed of an integrated motor chip, which is used to drive the two-phase current of the stepper motor through the control signal transmitted from the main control unit, so that the stepper motor can perform stepping speed and step amount.

[0014] The micro water pump drive subunit consists of a half-bridge drive architecture composed of NMOS and external resistors, which is used to control the flow rate and pressure of the micro water pump through the control signal transmitted from the main control unit.

[0015] Secondly, this application provides a method for surface inspection of high-altitude equipment based on a three-axis truss mechanism and a solid-state lidar, applied to the aforementioned surface inspection system for high-altitude equipment based on a three-axis truss mechanism and a solid-state lidar, comprising: The external components are used to acquire in real time three-dimensional point cloud data of the surface of the aerial work platform, the current pose data of the end effector, the speed and angle information of the stepper motor, the magnetic powder spraying flow rate information of the micro water pump, and the contact force between the end effector and the surface of the aerial work platform.

[0016] The acquired information on the stepper motor's rotational speed and angle, the magnetic powder spraying flow rate of the micro water pump, and the contact force between the end effector and the surface of the aerial work platform are transmitted to the signal processing unit for processing, and the processed data is sent to the main control unit. The signal processing unit processes the data according to a preset algorithm.

[0017] The acquired 3D point cloud data of the high-altitude equipment surface and the current pose data of the end effector are sent to the main control unit through the communication interface unit.

[0018] The main control unit uses the three-dimensional point cloud data of the surface of the high-altitude equipment and the preset information of the marked points on the surface of the high-altitude equipment to locate the marked points in real time in the lidar coordinate system; the marked points are the parts of the surface of the high-altitude equipment that need to be detected.

[0019] Based on the real-time positioning of the marker point and the current pose data of the end effector, the spatial offset between the current pose of the end effector and the marker point is calculated.

[0020] Based on the spatial offset, the speed and angle information of the stepper motor, the magnetic powder spraying flow rate information of the micro water pump, and the contact force between the end effector and the surface of the high-altitude equipment, the compensation motion commands for each linear motion module in the three-axis truss mechanism are determined.

[0021] The stepper motor in the three-axis truss mechanism is driven to move according to the compensation motion command, so that the detection device on the end effector moves to the mark point and maintains stable contact with the equipment surface.

[0022] Surface inspection is performed using an end effector.

[0023] Optionally, the main control unit, based on the three-dimensional point cloud data of the aerial equipment surface and the preset information of the marked points on the aerial equipment surface, locates the marked points in real time in the lidar coordinate system, specifically including: According to the formula The preset information of the marker points is parsed to obtain the position of the marker points in the solid-state lidar array matrix; the solid-state lidar array matrix is ​​a mapping matrix of the three-dimensional point cloud data acquired by the solid-state lidar on a two-dimensional plane; wherein, These are the x-coordinate and y-coordinate of the marker point in the coordinate system of the marker point plane, respectively. These represent the magnitudes of the x-coordinate and y-coordinate in the plane coordinate system of the marked point, respectively. These represent the x and y coordinates of the marker point mapped to the lidar data plane coordinate system, respectively. These represent the magnitudes of the horizontal and vertical axes in the lidar data plane coordinate system, respectively.

[0024] Optionally, the acquired stepper motor speed and angle information, the magnetic powder spraying flow rate information of the micro water pump, and the contact force between the end effector and the surface of the high-altitude equipment are transmitted to the signal processing unit for processing, specifically including: The signal processing unit is based on the formula Incremental displacement calculation is performed on the stepper motor's speed and angle information; among which, This represents the cumulative displacement from the start of the stepper motor to time t. The number of pulses per unit time, P is the ball screw lead, R is the reduction ratio, and E is the encoder resolution.

[0025] The signal processing unit is based on the formula The contact force between the end effector and the surface of the high-altitude equipment is calculated; where P1 is the pressure value to be measured, D is the raw digital output of the ADC, N is the sampling bit depth of the ADC, K is the calibration coefficient, S is the sensitivity coefficient of the strain gauge, and G is the structural coefficient of the elastic element.

[0026] Optionally, based on the real-time positioning of the marker point and the current pose data of the end effector, the spatial offset between the current pose of the end effector and the marker point is calculated, specifically including: According to the formula Feature vectors are extracted from the marked points to obtain feature vectors. ; According to the formula The coordinates of the marked points are normalized to obtain normalized coordinates (u,v): Based on the normalized coordinates (u,v) and eigenvectors Based on the formula Solve for the real-time three-dimensional position of the marker point in the sensor coordinate system. P marker =( x,y,z ); According to the formula The real-time three-dimensional position is optimized by weighted least squares to obtain the optimized real-time three-dimensional position. Establish a dynamic tracking model between consecutive frames; where, for a continuous time series t, t+1, ..., the time series of marker positions satisfy dynamic constraints: ; Based on the optimized real-time 3D position, and using the formula Calculate the spatial offset vector; in, These are the mean and standard deviation of the point cloud distance values ​​within the neighborhood, respectively; , is the average value vector of the color components in the neighborhood; , is the standard deviation vector of the color components in the neighborhood; These are the average and maximum brightness values ​​within the neighborhood, respectively; These represent the gradient magnitudes of distance and brightness in the two directions, respectively; W c H c These represent the magnitudes of the two directions in the lidar data plane coordinate system, where u and v represent the normalized coordinates. It is the inverse mapping function; This is the set of calibration parameters for the sensor. These are the weighting coefficients; This is an estimate of the velocity of the marker point; Δt is the time interval. This represents system noise.

[0027] According to the specific embodiments provided in this application, the following technical effects are disclosed: This application provides a system and method for surface inspection of high-altitude equipment based on a three-axis truss mechanism and solid-state lidar. This system combines a three-axis truss mechanism and solid-state lidar, and by acquiring real-time 3D point cloud data of the equipment surface and pose data of the end effector, it can accurately locate marker points on the surface of the high-altitude equipment. Using this data, the spatial offset between the end effector and the marker point is calculated, and the compensation motion command of the three-axis truss mechanism is determined accordingly. This enables the inspection device to accurately move to the marker point and make stable contact with the equipment surface, thereby achieving precise inspection of the high-altitude equipment surface. During the inspection process, the various components of the system work collaboratively. The solid-state lidar provides crucial 3D point cloud data, laying the foundation for subsequent positioning and inspection; the inertial measurement unit ensures accurate acquisition of the end effector's pose data; the encoder assembly and pressure sensor respectively provide feedback on the operating information of the stepper motor and the micro water pump, as well as the contact force between the end effector and the equipment surface, supporting precise control of the system. The control unit processes and analyzes this data, issuing corresponding commands to drive the stepper motor and the micro water pump, ensuring the smooth progress of the inspection operation. This system overcomes the problems of low efficiency and high risk associated with manual inspection. At the same time, the system can adjust the position and status of the inspection device in a timely manner according to the actual situation to ensure the accuracy and stability of the inspection. Attached Figure Description

[0028] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0029] Figure 1 A component framework diagram provided for an embodiment of this application.

[0030] Figure 2 This is a hardware function diagram provided for an embodiment of this application.

[0031] Figure 3 This is a data or signal flow diagram between the various components of the architecture provided in an embodiment of this application.

[0032] Figure 4 This is a schematic diagram of a three-axis truss mechanism provided in an embodiment of this application.

[0033] Figure 5 This is a logic diagram for surface detection of high-altitude equipment provided in an embodiment of this application.

[0034] Figure 6 A flowchart of a high-altitude equipment surface inspection process provided in an embodiment of this application.

[0035] Figure 7 This is a schematic diagram of a method for surface inspection of high-altitude equipment based on a three-axis truss mechanism and solid-state lidar, provided as an embodiment of this application. Detailed Implementation

[0036] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0037] To make the above-mentioned objectives, features and advantages of this application more apparent and understandable, the application will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0038] Example 1 like Figure 1 As shown, this application provides a high-altitude equipment surface inspection system based on a three-axis truss mechanism and a solid-state lidar, comprising: External components include a solid-state lidar, an inertial measurement unit, an encoder assembly, a pressure sensor, a stepper motor, and a miniature water pump. The solid-state lidar acquires three-dimensional point cloud data of the surface of the aerial work platform. The inertial measurement unit measures the current pose data of the end effector. The encoder assembly senses the rotational speed and angle information of the stepper motor and the magnetic powder spraying flow rate information of the miniature water pump, and feeds the rotational speed and angle information and the magnetic powder spraying flow rate information back to the main control unit. The pressure sensor senses the positioning status of the end effector. The stepper motor drives the three-axis truss mechanism to perform displacement actions. The miniature water pump sprays magnetic suspension during magnetic powder detection. The pressure sensor detects the contact force between the end effector and the surface of the aerial work platform.

[0039] The adjustment mechanism includes a three-axis truss mechanism and an end effector installed at the end of the adjustment mechanism and integrating at least one surface inspection device; the three-axis truss mechanism includes three linear motion modules orthogonally arranged in three-dimensional space, each linear motion module is driven by a stepper motor and converts rotational motion into linear motion through a ball screw; the surface inspection device includes an electromagnetic ultrasonic thickness measuring device and a magnetic particle flaw detection device.

[0040] The control unit includes a main control unit, a signal processing unit, a communication interface unit, and a motor drive unit. The main control unit consists of a microcontroller (MCU) and peripheral circuits. The peripheral circuits include an external power supply filter circuit, a download circuit, and an interface protection circuit. The signal processing unit processes the data detected by the pressure sensor and encoder assembly and sends the processed data to the main control unit. The communication interface unit is connected to the inertial measurement unit and the solid-state lidar signal. The motor drive unit receives commands from the main control unit and drives the stepper motor and the micro water pump. The control unit also includes a power supply system.

[0041] The drone platform is connected to the three-axis truss mechanism via a bracket.

[0042] In this embodiment, the system consists of a three-axis truss mechanism, a solid-state lidar, a detection device (thickness measurement / magnetic particle inspection), a control unit, and a UAV platform, forming a closed-loop control system of "detection-feedback-compensation".

[0043] Specifically, such as Figure 5 As shown, the truss mechanical system comprises a three-axis truss mechanism and an end effector. (As...) Figure 4As shown, in the three-axis truss mechanism, the X-axis serves as the horizontal positioning axis, using ball screw drive with a stroke of 300mm and a repeatability accuracy controllable within ±0.1mm; the Y-axis is the vertical lifting axis, also using ball screw drive with a stroke of 100mm; the Z-axis serves as the telescopic positioning axis, also using ball screw drive with a stroke of 300mm; at the same time, the entire structure is designed with lightweight carbon fiber composite materials, resulting in an overall weight of ≤1kg.

[0044] The end effector integrates an electromagnetic ultrasonic thickness measuring device, a magnetic particle flaw detection device consisting of an electromagnet and a magnetic powder spraying system, and a solid-state lidar with a ranging accuracy of ±1mm and a scanning frequency of 30Hz.

[0045] The hardware comprises a control unit, a sensor system, and actuators. The control unit uses an STM32F405 main control chip, a TMC2209 stepper motor driver for motion control, and a communication module that interacts with the UAV's data transmission link via a TTL serial port. Power management utilizes a 12V / 24V dual-channel DC-DC converter. The sensor system includes a solid-state LiDAR, an IMU (Inertial Measurement Unit), an encoder, and a pressure sensor for detecting contact forces. The actuators consist of a 28-series stepper motor and a miniature water pump that controls the spraying of magnetic powder.

[0046] In some embodiments, such as Figure 2 As shown, (1) Main control unit: The main control unit consists of a single-chip microcomputer (MCU) and corresponding peripheral circuits, including external power supply filtering circuit, download circuit, and interface protection circuit. Its main working contents are as follows: a) Receives digital signals from external sensors (solid-state LiDAR, encoder components) via its own peripherals (through TTL serial port peripherals).

[0047] b) Receives analog signals from external sensors (pressure sensors, encoder components) after they have been conditioned by the data acquisition unit (via the ADC peripheral).

[0048] c) Drive external actuators (stepper motors, micro water pumps) through its own peripherals in conjunction with the motor drive unit.

[0049] d) Run the driving algorithms at each level, such as Figure 6 As shown, it includes: i. Combining encoder feedback information, the motor position and speed closed-loop algorithm is run, and the peripheral settings output is given. Then, the output is sent to the motor drive unit to drive the stepper motor to rotate, so that each axis of the three-axis truss mechanism performs the corresponding displacement.

[0050] ii. Based on the set information, the pump output control algorithm is calculated, and the set output of the peripheral device is given. Then, the output is sent to the motor drive unit to drive the micro pump to run and execute the spraying flow rate and pressure under the set information.

[0051] iii. By combining feedback information from the IMU inertial measurement unit, pressure sensor, and solid-state lidar, the system runs algorithms for marker positioning, real-time calculation of relative offset, and position detection to provide the target displacement that each axis of the three-axis truss mechanism needs to perform, and monitors the position status of the end mechanism in real time.

[0052] (2) Signal processing unit: The signal processing unit mainly consists of amplification and filtering circuits. It serves as a bridge between external sensors (pressure sensors, encoder components) and the main control unit. It is used to condition the analog signals transmitted from external sensors so that the main control unit can receive and process sensor data more accurately.

[0053] (3) Communication interface unit: The communication interface unit is mainly composed of interface circuits, which serve as a bridge between external sensors (LiDAR, encoder components) and the main control unit, providing a physical connection for the digital signals transmitted from the sensors.

[0054] (4) Motor drive unit: The motor drive power supply mainly includes a stepper motor drive subunit and a micro water pump drive subunit; the stepper motor drive subunit is a stepper motor drive composed of integrated chips, and the micro water pump drive subunit is a DC motor speed control drive (driving the micro water pump) composed of discrete MOS, as detailed below: a) The stepper motor drive subunit is mainly composed of an integrated motor chip. It drives the two-phase current of the external stepper motor through the control signal (PWM) transmitted from the main control unit, thereby executing the corresponding stepping speed and step amount.

[0055] b) The micro water pump drive subunit is a DC motor speed control drive, which consists of a half-bridge drive architecture composed of NMOS and external resistors. It controls the flow and pressure of the external micro water pump through the control signal (PWM duty cycle) transmitted from the main control unit.

[0056] (5) Power supply system topology: The power supply system topology consists of various DC-DC power supply circuits and precision power supply circuits, the details of which are as follows: a) DC-DC power supply circuit: provides power for the microcontroller's digital power input, motor drive unit, and some external sensors to meet different power requirements.

[0057] b) Precision power supply circuit: provides precise and reliable drive power and reference power for the signal processing unit and some external sensors.

[0058] (6) In external components, such as Figure 5As shown, solid-state lidar, inertial measurement unit (IMU), encoder assembly, and pressure sensor are used for multi-mode sensing, specifically: a) Solid-state lidar: Used for macroscopic perception of the relative displacement state between the end effector and the marked point, and outputs a range matrix of the array.

[0059] b) IMU (Inertial Measurement Unit): Used to sense the current spatial angular displacement of the end effector.

[0060] c) Encoder assembly: used to sense the speed and angle information of the stepper motor and then supply it to the main control unit to calculate the displacement of each axis.

[0061] d) Pressure sensor: used to sense the position status of the end effector.

[0062] e) Stepper motor: Used to drive the truss of each axis to perform the corresponding displacement.

[0063] f) Miniature water pump: used for spraying magnetic suspension liquid during magnetic particle testing.

[0064] In some embodiments, such as Figure 3 As shown, the software architecture of this system adopts a layered design. The drive layer is responsible for motor control and sensor data acquisition, the algorithm layer undertakes position detection, compensation calculation, and motion planning tasks, and the application layer implements detection control, data management, and human-computer interaction functions. The core algorithms of this software architecture include lidar data processing algorithms (covering voxel filtering and radius filtering in point cloud filtering, cylindrical surface fitting in feature extraction, and three-dimensional coordinate transformation from lidar to the workpiece coordinate system), position compensation algorithms (involving IMU-based UAV attitude compensation, lidar-based workpiece surface compensation, and inverse kinematics calculation for three-axis linkage control), and detection control algorithms (including adaptive contact force control, detection path planning for helical scanning, and data synchronization acquisition with timestamp alignment). Specifically, when controlling based on this software architecture, the control flow is as follows: the UAV arrives at the detection area, the lidar scans the workpiece surface and establishes an initial coordinate system, the detection path is planned according to the detection task, the position deviation is detected in real time and the three-axis compensation is calculated, the movement of the three-axis truss mechanism is controlled to keep the position of the detection device and the workpiece surface constant, thickness measurement / flaw detection is performed simultaneously, and finally, data storage and transmission are completed.

[0065] Example 2 like Figure 7 As shown, this embodiment provides a method for surface inspection of high-altitude equipment based on a three-axis truss mechanism and a solid-state lidar, applied to the aforementioned surface inspection system for high-altitude equipment based on a three-axis truss mechanism and a solid-state lidar, including: Step 1: Using the external components, acquire in real time the three-dimensional point cloud data of the surface of the aerial work platform, the current pose data of the end effector, the speed and angle information of the stepper motor, the magnetic powder spraying flow rate information of the micro water pump, and the contact force between the end effector and the surface of the aerial work platform.

[0066] Step 2: The acquired stepper motor speed and angle information, micro water pump magnetic powder spraying flow rate information, and end effector contact force with the surface of the high-altitude equipment are transmitted to the signal processing unit for processing, and the processed data is sent to the main control unit; the signal processing unit processes the stepper motor speed and angle information, micro water pump magnetic powder spraying flow rate information, and end effector contact force with the surface of the high-altitude equipment according to a preset algorithm.

[0067] Step 3: The acquired 3D point cloud data of the high-altitude equipment surface and the current pose data of the end effector are sent to the main control unit through the communication interface unit.

[0068] Step 4: The main control unit uses the 3D point cloud data of the aerial equipment surface combined with the preset information of the marker points on the aerial equipment surface to locate the marker points in real time in the lidar coordinate system; the marker points are the parts of the aerial equipment surface that need to be detected.

[0069] Step 5: Based on the real-time positioning of the marker point and the current pose data of the end effector, calculate the spatial offset between the current pose of the end effector and the marker point.

[0070] Step 6: Based on the spatial offset, the speed and angle information of the stepper motor, the magnetic powder spraying flow rate information of the micro water pump, and the contact force between the end effector and the surface of the high-altitude equipment, determine the compensation motion command for each linear motion module in the three-axis truss mechanism.

[0071] Step 7: Drive the stepper motor in the three-axis truss mechanism to move according to the compensation motion command, so that the detection device on the end effector moves to the mark point and maintains stable contact with the equipment surface.

[0072] Step 8: Perform surface inspection operations based on the end effector.

[0073] In some embodiments, the main control unit locates the marker points in real time in the lidar coordinate system based on the three-dimensional point cloud data of the high-altitude equipment surface and the preset information of the marker points on the high-altitude equipment surface. Specifically, this includes: After the closed-loop software control algorithm is started, it receives the incoming data information, parses out the corresponding marker point information and the data transmitted from each sensor, and then performs marker point information parsing: based on the externally input or preset marker point information, it parses and maps the position of the marker point in the solid-state lidar array matrix, and maps the plane where the marker point is set to the lidar data plane (a two-dimensional mapping function).

[0074] Specifically, according to the formula The preset information of the marker points is parsed to obtain the position of the marker points in the solid-state lidar array matrix; the solid-state lidar array matrix is ​​a mapping matrix of the three-dimensional point cloud data acquired by the solid-state lidar on a two-dimensional plane; wherein, These are the x-coordinate and y-coordinate of the marker point in the coordinate system of the marker point plane, respectively. These represent the magnitudes of the x-coordinate and y-coordinate in the plane coordinate system of the marked point, respectively. These represent the x and y coordinates of the marker point mapped to the lidar data plane coordinate system, respectively. These represent the magnitudes of the horizontal and vertical axes in the lidar data plane coordinate system, respectively.

[0075] IMU attitude sensor data parsing: Parse the three-axis attitude angle and three-axis angular velocity information according to the attitude sensor data format.

[0076] Solid-state lidar data parsing: Parse the solid-state lidar sensor data format to extract matrices containing distance, color, and brightness information for each point on its data plane.

[0077] The acquired information, including the stepper motor's speed and angle, the micro water pump's magnetic powder spraying flow rate, and the contact force between the end effector and the surface of the high-altitude equipment, is transmitted to the signal processing unit for processing. Specifically, this includes: The signal processing unit is based on the formula Incremental displacement calculation is performed on the stepper motor's speed and angle information; among which, This represents the cumulative displacement from the start of the stepper motor to time t. The number of pulses per unit time, P is the ball screw lead, R is the reduction ratio, and E is the encoder resolution.

[0078] The signal processing unit is based on the formula The contact force between the end effector and the surface of the high-altitude equipment is calculated; where P1 is the pressure value to be measured, D is the raw digital output of the ADC, N is the sampling bit depth of the ADC, K is the calibration coefficient (which includes correction factors for all electronic components such as bridge excitation voltage and amplifier gain), S is the sensitivity coefficient (or strain factor) of the strain gauge, and G is the structural coefficient of the elastic element.

[0079] Specifically, based on the real-time positioning of the marker points and the current pose data of the end effector, the spatial offset between the current pose of the end effector and the marker points is calculated, including: According to the formula Feature vectors are extracted from the marked points to obtain feature vectors. .

[0080] According to the formula The coordinates of the marked points are normalized to obtain normalized coordinates (u,v): Based on the normalized coordinates (u,v) and eigenvectors Based on the formula Solve for the real-time three-dimensional position of the marker point in the sensor coordinate system. P marker =( x,y,z ).

[0081] According to the formula The real-time three-dimensional position is optimized by weighted least squares to obtain the optimized real-time three-dimensional position.

[0082] Establish a dynamic tracking model between consecutive frames; where, for a continuous time series t, t+1, ..., the time series of marker positions satisfy dynamic constraints: .

[0083] Based on the optimized real-time 3D position, and using the formula Calculate the spatial offset vector.

[0084] The projection offset in the data plane coordinate system is: in, These are the mean and standard deviation of the point cloud distance values ​​within the neighborhood, respectively; , is the average value vector of the color components in the neighborhood; , is the standard deviation vector of the color components in the neighborhood; These are the average and maximum brightness values ​​within the neighborhood, respectively. , representing the gradient magnitudes of distance and brightness in the two directions, respectively, characterizing the local rate of change; W c H c These are the magnitudes of the two directions in the plane coordinate system of the lidar data, and u and v represent the normalized coordinates, where the normalized coordinates u and v ∈ [0, 1]. It is the inverse mapping function; This is the set of calibration parameters for the sensor. These are weighting coefficients that balance feature matching error and coordinate projection error; The velocity of the marker point is estimated (based on IMU data; a general method is not described in detail); Δt is the time interval. The system noise is represented by ΔX and ΔY, which are the pixel offsets on the sensor plane. For the Z-axis direction, a pressure sensor is used to monitor a threshold to determine if the position is correct; the output values ​​of the stepper motor displacement and speed for each axis are calculated based on the plane offset.

[0085] In the specific measurement process of this embodiment, the system is first carried by a drone to the detection area, and the three-axis truss mechanism is installed under the drone using a shock-absorbing bracket. Next, a solid-state LiDAR is fitted to the end of the three-axis truss mechanism and coaxially mounted with the detection device.

[0086] The control software is responsible for functions such as UAV attitude calculation, LiDAR data processing, three-axis motion control, and inspection task management. Calibration experiments were then conducted to establish the transformation relationship between the LiDAR coordinate system and the workpiece coordinate system.

[0087] During actual inspection, the system can automatically complete workpiece surface scanning, inspection path planning, real-time position compensation, and data acquisition and storage. If the drone experiences slight shaking (maximum tilt angle of 5°) during inspection, and the lidar detects a 3mm displacement on the tank surface, the system will calculate the compensation amount and control the three-axis mechanism to adjust its position, thereby completing the inspection of the entire tank.

[0088] In summary, this application has the following technical effects: This application achieves significant technical results through core technologies such as solid-state lidar real-time positioning (achieving millimeter-level dynamic positioning with a 30Hz scanning frequency), three-axis linkage compensation control (closed-loop control based on a spatial coordinate system, with compensation calculation accuracy up to 0.1mm), an adaptive detection system (automatically adjusting detection parameters according to workpiece surface characteristics), lightweight integrated design (achieving multi-axis displacement on a 1kg weight basis), and multi-sensor fusion (a composite positioning system of IMU + lidar + encoder). The detection and positioning accuracy reaches ±0.5mm (after compensation), and the detection efficiency is 3-5 times higher than manual detection. It can adapt to the detection of cylindrical equipment with diameters of 1-10m, and eliminates the need for manual climbing, thus reducing operational risks. Simultaneously, it ensures accurate correlation between detection data and position information for convenient subsequent analysis. Through the coordinated control of a three-axis truss mechanism and solid-state lidar, this application realizes intelligent and automated high-altitude equipment detection, effectively solving the problems of low efficiency, poor accuracy, and poor safety in traditional detection methods, and has broad application prospects.

[0089] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0090] This document uses specific examples to illustrate the principles and implementation methods of this application. The descriptions of the above embodiments are only for the purpose of helping to understand the methods and core ideas of this application. Furthermore, those skilled in the art will recognize that, based on the ideas of this application, there will be changes in the specific implementation methods and application scope. Therefore, the content of this specification should not be construed as a limitation of this application.

Claims

1. A surface inspection system for high-altitude equipment based on a three-axis truss mechanism and a solid-state lidar, characterized in that, include: External components include solid-state lidar, inertial measurement unit, encoder assembly, pressure sensor, stepper motor and miniature water pump; The adjustment mechanism includes a three-axis truss mechanism and an end effector installed at the end of the adjustment mechanism and integrating at least one surface detection device; The control unit includes a main control unit, a signal processing unit, a communication interface unit, and a motor drive unit. The main control unit consists of a microcontroller (MCU) and peripheral circuits. The peripheral circuits include an external power supply filter circuit, a download circuit, and an interface protection circuit. The signal processing unit processes the data detected by the pressure sensor and encoder assembly and sends the processed data to the main control unit. The communication interface unit is connected to the inertial measurement unit and the solid-state lidar signal. The motor drive unit receives commands from the main control unit and drives the stepper motor and the micro water pump. The drone platform is connected to the three-axis truss mechanism via a bracket.

2. The high-altitude equipment surface inspection system based on a three-axis truss mechanism and solid-state lidar according to claim 1, characterized in that, The solid-state lidar is used to acquire three-dimensional point cloud data of the surface of the high-altitude equipment; the inertial measurement unit is used to measure the current pose data of the end effector; the encoder assembly is used to sense the speed and angle information of the stepper motor and the magnetic powder spraying flow rate information of the micro water pump, and feeds back the speed and angle information and the magnetic powder spraying flow rate information to the main control unit; the pressure sensor is used to sense the positioning status of the end effector; the stepper motor is used to drive the three-axis truss mechanism to perform displacement actions; the micro water pump is used to spray magnetic suspension liquid during magnetic powder detection; the pressure sensor is used to detect the contact force between the end effector and the surface of the high-altitude equipment.

3. The high-altitude equipment surface inspection system based on a three-axis truss mechanism and solid-state lidar according to claim 1, characterized in that, The control unit also includes a power supply system.

4. The high-altitude equipment surface inspection system based on a three-axis truss mechanism and solid-state lidar according to claim 1, characterized in that, The three-axis truss mechanism includes three linear motion modules orthogonally arranged in three-dimensional space. Each linear motion module is driven by a stepper motor and converts rotational motion into linear motion through a ball screw.

5. The high-altitude equipment surface inspection system based on a three-axis truss mechanism and solid-state lidar according to claim 1, characterized in that, The surface inspection device includes an electromagnetic ultrasonic thickness measuring device and a magnetic particle flaw detection device.

6. The high-altitude equipment surface inspection system based on a three-axis truss mechanism and solid-state lidar according to claim 1, characterized in that, The motor drive unit includes a stepper motor drive subunit and a micro water pump drive subunit; The stepper motor driver unit is composed of an integrated motor chip, which is used to drive the two-phase current of the stepper motor through the control signal transmitted from the main control unit, so that the stepper motor can perform stepping speed and step amount. The micro water pump drive subunit consists of a half-bridge drive architecture composed of NMOS and external resistors, which is used to control the flow rate and pressure of the micro water pump through the control signal transmitted from the main control unit.

7. A method for surface inspection of high-altitude equipment based on a three-axis truss mechanism and solid-state lidar, characterized in that, A high-altitude equipment surface inspection system based on a three-axis truss mechanism and solid-state lidar, as described in any one of claims 1-6, comprises: The external components are used to acquire in real time three-dimensional point cloud data of the surface of the aerial work platform, the current pose data of the end effector, the speed and angle information of the stepper motor, the magnetic powder spraying flow rate information of the micro water pump, and the contact force between the end effector and the surface of the aerial work platform. The acquired information on the stepper motor's rotational speed and angle, the magnetic powder spraying flow rate of the micro water pump, and the contact force between the end effector and the surface of the aerial work platform are transmitted to the signal processing unit for processing, and the processed data is sent to the main control unit. The signal processing unit processes the data according to a preset algorithm. The acquired 3D point cloud data of the high-altitude equipment surface and the current pose data of the end effector are sent to the main control unit through the communication interface unit; The main control unit uses the three-dimensional point cloud data of the surface of the high-altitude equipment and the preset information of the marked points on the surface of the high-altitude equipment to locate the marked points in real time in the lidar coordinate system; the marked points are the parts of the surface of the high-altitude equipment that need to be detected. Based on the real-time positioning of the marker point and the current pose data of the end effector, calculate the spatial offset between the current pose of the end effector and the marker point; Based on the spatial offset, the speed and angle information of the stepper motor, the magnetic powder spraying flow rate information of the micro water pump, and the contact force between the end effector and the surface of the high-altitude equipment, the compensation motion command of each linear motion module in the three-axis truss mechanism is determined. According to the compensation motion command, the stepper motor in the three-axis truss mechanism is driven to move, so that the detection device on the end effector moves to the mark point and maintains stable contact with the equipment surface; Surface inspection is performed using an end effector.

8. The method for surface inspection of high-altitude equipment based on a three-axis truss mechanism and solid-state lidar according to claim 7, characterized in that, The main control unit, based on the 3D point cloud data of the high-altitude equipment surface and the preset information of the marked points on the high-altitude equipment surface, locates the marked points in real time in the lidar coordinate system, specifically including: According to the formula The preset information of the marker points is parsed to obtain the position of the marker points in the solid-state lidar array matrix; the solid-state lidar array matrix is ​​a mapping matrix of the three-dimensional point cloud data acquired by the solid-state lidar on a two-dimensional plane; wherein, These are the x-coordinate and y-coordinate of the marker point in the coordinate system of the marker point plane, respectively. These represent the magnitudes of the x-coordinate and y-coordinate in the plane coordinate system of the marked point, respectively. These represent the x and y coordinates of the marker point mapped to the lidar data plane coordinate system, respectively. These represent the magnitudes of the horizontal and vertical axes in the lidar data plane coordinate system, respectively.

9. The method for surface inspection of high-altitude equipment based on a three-axis truss mechanism and solid-state lidar according to claim 7, characterized in that, The acquired information on the stepper motor's speed and angle, the magnetic powder spraying flow rate of the micro water pump, and the contact force between the end effector and the surface of the high-altitude equipment are transmitted to the signal processing unit for processing, specifically including: The signal processing unit is based on the formula Incremental displacement calculation is performed on the stepper motor's speed and angle information; among which, This represents the cumulative displacement from the start of the stepper motor to time t. The number of pulses per unit time, where P is the ball screw lead, R is the reduction ratio, and E is the encoder resolution; The signal processing unit is based on the formula The contact force between the end effector and the surface of the high-altitude equipment is calculated; where P1 is the pressure value to be measured, D is the raw digital output of the ADC, N is the sampling bit depth of the ADC, K is the calibration coefficient, S is the sensitivity coefficient of the strain gauge, and G is the structural coefficient of the elastic element.

10. The method for surface inspection of high-altitude equipment based on a three-axis truss mechanism and solid-state lidar according to claim 7, characterized in that, Based on the real-time positioning of the marker points and the current pose data of the end effector, the spatial offset between the current pose of the end effector and the marker points is calculated, specifically including: According to the formula Feature vectors are extracted from the marked points to obtain feature vectors. ; According to the formula The coordinates of the marked points are normalized to obtain normalized coordinates (u,v): Based on the normalized coordinates (u,v) and eigenvectors Based on the formula Solve for the real-time three-dimensional position of the marker point in the sensor coordinate system. P marker =( x,y,z ); According to the formula The real-time three-dimensional position is optimized by weighted least squares to obtain the optimized real-time three-dimensional position. Establish a dynamic tracking model between consecutive frames; where, for a continuous time series t, t+1, ..., the time series of marker positions satisfy dynamic constraints: ; Based on the optimized real-time 3D position, and using the formula Calculate the spatial offset vector; in, These are the mean and standard deviation of the point cloud distance values ​​within the neighborhood, respectively; , is the average value vector of the color components in the neighborhood; , is the standard deviation vector of the color components in the neighborhood; These are the average and maximum brightness values ​​within the neighborhood, respectively; These represent the gradient magnitudes of distance and brightness in the two directions, respectively; W c H c These represent the magnitudes of the two directions in the lidar data plane coordinate system, where u and v represent the normalized coordinates. It is the inverse mapping function; This is the set of calibration parameters for the sensor. These are the weighting coefficients; This is an estimate of the velocity of the marker point; Δt is the time interval. This represents system noise.

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