AGV four-steering-wheel automatic calibration system and dynamic compensation method

Abstract

The invention provides an AGV four-steering-wheel automatic calibration system and a dynamic compensation method, and belongs to the field of mobile robots and automatic control. According to the method, the vehicle pose is detected in real time through laser ranging, and meanwhile, the steering wheel angle is automatically compensated by combining analysis and calculation of the turning radius, so that special errors are eliminated through 90-degree rotation and translation detection, and efficient and accurate calibration is achieved. The AGV four-steering-wheel automatic calibration system comprises a vehicle end device which comprises at least two sets of sensors installed on the head of a vehicle in parallel; the fixed end equipment comprises a receiving panel and a coordinate calibration module; the control unit is used for receiving the detection data of the sensor and the light spot coordinate data so as to complete vehicle pose calculation, trajectory analysis and dynamic adjustment of the steering wheel angle; the system interacts with the vehicle end device, the fixed end device and the steering wheel driving module in real time, and is internally provided with a pose calculation unit, a track fitting unit, a radius analysis unit, a dynamic compensation calculation unit and a rotation detection unit.

Description

Technical Field

[0001] This application relates to the field of mobile robots and automated control, and specifically proposes a four-rudder wheel calibration system and dynamic compensation method. Background Technology

[0002] With the development and progress of industrial automation technology, various mobile robots, such as AGVs (Automated Guided Vehicles) and unmanned delivery vehicles, are now widely used in logistics warehousing transfer stations and automated production sites. These transportation devices generally adopt a four-wheel omnidirectional drive system, thus playing an increasingly important role in material turnover and transportation.

[0003] The four-steering wheel drive system is characterized by its flexible steering, and the installation accuracy of the steering wheels directly determines the vehicle's accuracy along the planned route. However, in actual production and assembly, due to factors such as machining errors, assembly process deviations, and component deformation, the actual installation direction of the steering wheels often cannot be perfectly parallel to the longitudinal axis of the vehicle body, resulting in varying degrees of installation errors. Such installation errors will lead to problems such as trajectory deviation, steering lag, and increased energy consumption during vehicle operation, and in severe cases, may even cause safety accidents.

[0004] In existing technologies, the direction calibration of four steering wheels mostly relies on manual measurement and adjustment. This involves manually measuring the angles of each steering wheel using tools such as angle meters and measuring tapes, and then manually adjusting the steering wheel parameters. This method has the following drawbacks: First, the calibration efficiency is low, requiring professional personnel and taking a long time per calibration; second, the calibration accuracy is low, as manual measurements are easily affected by subjective factors and it is difficult to accurately compensate for installation errors; third, it has poor applicability, failing to adapt to dynamic error correction under different operating conditions, and it is difficult to effectively identify and compensate for special error forms such as "inward yaw" and "outward yaw". Therefore, there is an urgent need for a solution that can automatically identify the installation errors of the four steering wheels and accurately complete the direction calibration to overcome the shortcomings of existing manual calibration methods.

[0005] In view of the above, this patent application is hereby filed. Summary of the Invention

[0006] The AGV four-steering wheel automatic calibration system and dynamic compensation method described in this application aim to solve the problems existing in the prior art by proposing a solution that uses laser ranging to detect the vehicle's position and posture in real time, and combines the analysis and calculation of the turning radius to implement automatic compensation of the steering wheel angle. The goal is to eliminate special errors through 90-degree rotation and translation detection and achieve efficient and accurate calibration.

[0007] To achieve the above design objectives, the AGV four-steering wheel automatic calibration system consists of the following modules:

[0008] Vehicle-side equipment includes at least two sets of sensors mounted parallel to each other at the front of the vehicle;

[0009] The fixed-end equipment includes a receiving panel and a coordinate calibration module; the coordinate calibration module is used to establish a test plane coordinate system with the horizontal center line of the receiving panel as the X-axis and the direction of the vehicle head as the positive Y-axis, and the origin O of the coordinate system is the geometric center of the receiving panel.

[0010] The control unit receives sensor detection data and spot coordinate data to perform vehicle pose calculation, trajectory analysis, and dynamic adjustment of steering wheel angle. It interacts in real time with vehicle-side equipment, fixed-side equipment, and steering wheel drive module, and has built-in pose calculation unit, trajectory fitting unit, radius analysis unit, dynamic compensation calculation unit, and rotation detection unit. The dynamic compensation calculation unit is used to perform angle compensation calculation and a method to eliminate special errors through 90-degree rotation and translation detection.

[0011] Furthermore, the sensor is a laser rangefinder, with two sets of laser rangefinders located at the front of the vehicle, with a distance L between them and the laser emission direction being parallel to the longitudinal axis of the vehicle.

[0012] Based on the above-mentioned AGV four-steering wheel automatic calibration system, this application also proposes an AGV four-steering wheel dynamic compensation method, which includes the following steps:

[0013] Step (1), Initialization;

[0014] Step (2): Real-time detection of vehicle position and posture;

[0015] The control unit is based on the synchronous operation of two sets of laser rangefinders to collect data. Time laser rangefinder Distance collected Laser rangefinder Distance collected Simultaneously, it acquires data through the laser receiving panel. The laser rangefinder's spot coordinates Laser rangefinder Light spot coordinates The pose calculation unit calculates the vehicle's position based on the above data. Real-time pose of the vehicle at any given moment, including the coordinates of the vehicle's center point. The angle between the vehicle's longitudinal axis and the y-axis of the map coordinate system ;

[0016] Step (3), turning radius analysis;

[0017] The AGV pose at times t and t+1 is changed by... and The straight lines form the following equation:

[0018]

[0019] Then, the R of the vehicle's rotation center at times t and t+1 is obtained. (t) The coordinates are as follows:

[0020]

[0021] Real-time turning radius The expression is as follows:

[0022]

[0023] The real-time turning radius is determined by the radius analysis unit. Compare with the preset threshold thr, if If this condition is met for several consecutive sampling periods, the current driving trajectory of the vehicle is determined to be a stable straight line, the steering wheel direction does not need to be adjusted, and the calibration is completed; proceed directly to the following step (5).

[0024] like Or, at least one period in several consecutive sampling periods does not meet the requirement. If the condition is met, it is determined that the vehicle has a directional deviation and proceeds to the following step (4).

[0025] Step (4): Automatic compensation of steering wheel angle;

[0026] Based on the vehicle pose calculated in step (2), the rotation center coordinates and turning radius obtained in step (3), the angle compensation of the four steering wheels is determined to achieve the following angle compensation.

[0027] Step (5), error detection and secondary calibration;

[0028] After the routine error compensation in the straight direction is completed, further identify and correct the installation errors of the inward and / or outward octagonal positions.

[0029] Furthermore, in step (1), the four-wheel AGV is parked at a preset distance directly in front of the laser receiving panel to ensure that the lasers from both sets of laser rangefinders can be projected onto the laser receiving panel; the AGV four-wheel automatic calibration system is started, and the test plane coordinate system is calibrated and known parameters are entered through the coordinate calibration module.

[0030] Further, step (2) includes step (2.1), calculating the vehicle's heading angle θ(t) at time t;

[0031] The heading angle θ(t) is the coordinate axis x v The angle between the coordinate axis and the Y-axis is calculated as follows, with left deviation being positive and right deviation being negative:

[0032]

[0033]

[0034] Then at time t, x v The angle between the coordinate axis and the X-axis is: ;;

[0035] Step (2.2): Calculate the coordinates of the dual laser rangefinder at time t;

[0036] The calculation formula is as follows:

[0037]

[0038] in, Let x be the x-coordinate of the laser spot on the laser receiver panel of laser rangefinder A at time t. Let x be the x-coordinate of the laser spot on the laser receiver panel of laser rangefinder B at time t;

[0039] Calculate the coordinates of the vehicle's physical center V at time t using the following formula:

[0040]

[0041] The transformation matrix from the vehicle coordinate system to the map coordinate system is:

[0042] Where D is the vertical distance from the vehicle's physical center V to the line connecting the two laser rangefinders.

[0043] Furthermore, step (4) includes step (4.1), calculating the deflection angle;

[0044] At time t+1, the steering wheel and R (t+1) The slope of the line in the map coordinate system is:

[0045]

[0046] At time t+1, the angle between the steering wheel and the positive Y-axis is:

[0047]

[0048] The steering wheel deflection angle at time t+1 is:

[0049]

[0050] Then, the angle value of the steering wheel after compensation at time t+1 is:

[0051]

[0052] in, The actual angle value of the steering wheel obtained by the motor driver at time t;

[0053] Step (4.2), compensation value filtering;

[0054] To prevent abnormal offset calculations due to factors such as slippage, abnormal calculated values ​​need to be filtered out as follows:

[0055]

[0056] If the above conditions are met, proceed to step (4.3) below to perform angle compensation; otherwise, it should be determined that there is serious slippage, delete the current calculation data and proceed to step (2).

[0057] Step (4.3), closed-loop iterative compensation;

[0058] After the steering wheel adjustment is completed, the actual angle is fed back to the control unit;

[0059] The angle compensation unit's adjustment accuracy is verified using the following formula:

[0060]

[0061] in, This is the actual angle of the adjusted steering wheel;

[0062] If the above formula is true, the adjustment of the wheel is deemed valid; otherwise, return to step (4.1) to recalculate the compensation amount and adjust again; after the adjustment of the four steering wheels is completed, return to step (2).

[0063] Furthermore, step (5) includes step (5.1), 90-degree synchronous rotation control;

[0064] The control module controls the four steering wheels to rotate synchronously by 90 degrees, with a rotational angular velocity ≤30° / s, ensuring that the four steering wheels rotate at the same angle.

[0065] During rotation, the control unit collects the steering wheel angle data fed back by the motor driver in real time. When the steering wheel angle is continuously sampled for several seconds and meets the requirements... Determine when the steering wheel has rotated to the correct position;

[0066] Step (5.2), Lateral translation test;

[0067] Control the vehicle to travel laterally at a speed v, with a travel distance ≥ S;

[0068] During the driving process, repeat steps (2) and (3) for pose detection and turning radius calculation;

[0069] If during the translation process This indicates that the vehicle has no inward or outward toeing error, and the calibration is complete; if... If thr is the turning radius threshold, it indicates the presence of inward and / or outward yaw errors. Proceed to step (4) to calculate the angle offset. After angle compensation, proceed to step (2). Continue until the calculation results are consistent during the translation process. If the second calibration is successful, proceed to the following steps (5.3).

[0070] Step (5.3): Consolidation and traceability of calibration results;

[0071] After the second calibration is completed, the control unit saves the following data to the vehicle storage unit, including the initial angle of each steering wheel, the final compensation amount, the calibration time, and the trajectory data of the straight / translation test;

[0072] Generate a calibration report, which includes information such as whether the calibration is qualified, error type, compensation details, and test parameters. The report can be exported to a host computer via an Ethernet interface.

[0073] The control unit writes the final compensation amount into the parameter register of the steering wheel drive module. This compensation amount is automatically loaded when the vehicle is driving normally to ensure driving accuracy.

[0074] This application proposes a computer device including one or more processors and a storage device, wherein the storage device stores one or more programs, and when the one or more programs are executed by the one or more processors, the one or more processors implement the AGV four-steering wheel dynamic compensation method.

[0075] This application proposes a computer-readable storage medium storing a computer-executable program, which, when executed by a processor, implements the aforementioned AGV four-steering wheel dynamic compensation method.

[0076] In summary, the advantages and benefits of this application compared with the prior art are that it can effectively solve the problem of directional deviation caused by vehicle steering wheel installation error, propose an overall scheme to realize automatic steering wheel angle calibration, and the calibration results are accurate, which significantly reduces the occurrence of problems such as trajectory deviation and steering lag during the operation of mobile robots and autonomous vehicles, and correspondingly improves operational safety. Attached Figure Description

[0077] The accompanying drawings, which are included to provide a further understanding of this application and form part of this application, illustrate exemplary embodiments and are used to explain this application, but do not constitute an undue limitation of this application. Some specific embodiments of this application will be described in detail below with reference to the accompanying drawings in an exemplary and non-limiting manner. The same reference numerals in the drawings designate the same or similar parts or components. It should be understood by those skilled in the art that these drawings are not necessarily drawn to scale.

[0078] Figure 1 This is a structural block diagram of the AGV four-steering wheel automatic calibration system;

[0079] Figure 2 This is a flowchart of the dynamic compensation method for the four steering wheels of the AGV.

[0080] Figure 3 This is a schematic diagram of a vehicle's four-steering wheel drive system;

[0081] Figure 4 This is a schematic diagram of the vehicle status in the embodiment;

[0082] Figure 5 This is a schematic diagram for calculating the center of rotation;

[0083] Figure 6 This is a diagram illustrating the offset calculation;

[0084] Figure 7 This is a diagram illustrating the steering wheel's inward and outward yaw states; Detailed Implementation

[0085] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.

[0086] like Figure 1 As shown, this application proposes an automatic calibration system for four steering wheels of an AGV, which consists of the following modules:

[0087] Vehicle-side equipment includes at least two sets of sensors mounted parallel to each other at the front of the vehicle;

[0088] In this embodiment, a laser rangefinder is preferred, such as... Figure 3 As shown, two sets of laser rangefinders are located at the front of the vehicle, with a distance of L between them and the laser emission direction is parallel to the longitudinal axis of the vehicle.

[0089] Each laser rangefinder uses a high-precision ToF (Time of Flight) type, with a measurement frequency ≥100Hz and a distance measurement accuracy ≤±1mm, and can synchronously collect distance data from the test plane in front.

[0090] Fixed-end equipment, including a laser receiving panel and a coordinate calibration module;

[0091] The laser receiving panel is fixed to the ground (levelness error ≤ ±0.05°) to serve as the test plane. Its surface is equipped with coordinate scales (scale accuracy ≤ ±0.02mm). The laser receiving panel has a built-in CCD vision acquisition module, which is used to capture the laser spots emitted by the two sets of laser rangefinders in real time and output the coordinate positions of the laser spots. The frequency of the output laser spot coordinates is consistent with the measurement frequency of the laser rangefinders. The coordinate calibration module is used to establish a test plane coordinate system with the horizontal centerline of the laser receiving panel as the X-axis and the direction of the vehicle's front as the positive Y-axis. The origin O of the coordinate system is the geometric center of the laser receiving panel.

[0092] The control unit receives detection data and spot coordinate data from the laser rangefinder to perform vehicle pose calculation, trajectory analysis, and dynamic adjustment of the steering wheel angle. It interacts in real time with the vehicle-side equipment, the fixed-side equipment, and the steering wheel drive module, and has built-in pose calculation unit, trajectory fitting unit, radius analysis unit, dynamic compensation calculation unit, and rotation detection unit. The dynamic compensation calculation unit is used to perform angle compensation calculation and a method to eliminate special errors through 90-degree rotation and translation detection.

[0093] Based on the above-mentioned AGV four-steering wheel automatic calibration system, this application also proposes an AGV four-steering wheel dynamic compensation method including the following steps:

[0094] Step (1), Initialization;

[0095] like Figure 3 As shown, the four-wheeled AGV is parked at a preset distance directly in front of the laser receiving panel to ensure that the lasers from both sets of laser rangefinders can be projected onto the laser receiving panel.

[0096] The AGV four-steering wheel automatic calibration system is activated, and the test plane coordinate system is calibrated and known parameters are entered through the coordinate calibration module; including the distance L between the two sets of laser rangefinders, the vehicle's preset straight-line speed v, and the compensation iteration convergence threshold. ( (Used to determine whether the compensation meets the accuracy requirements) and abnormal deviation filtering threshold. (The actual installation error of the steering wheel can be preset) ), turning radius threshold thr (based on the requirements for straight-line accuracy of AGVs in GB / T 30826-2014 "General Technical Conditions for Automated Guided Vehicles", thr≥500m is set in combination with the actual vehicle model, and thr=800m is preferred, etc.);

[0097] Step (2): Real-time detection of vehicle position and posture;

[0098] like Figure 4 As shown, the control unit is based on the synchronous operation of two sets of laser rangefinders to collect data. Time laser rangefinder Distance collected Laser rangefinder Distance collected Simultaneously, it acquires data through the laser receiving panel. The laser rangefinder's spot coordinates Laser rangefinder Light spot coordinates The pose calculation unit calculates the vehicle's position based on the above data. Real-time pose of the vehicle at any given moment, including the coordinates of the vehicle's center point. The angle between the vehicle's longitudinal axis and the y-axis of the map coordinate system (i.e., vehicle heading angle); specifically including:

[0099] Step (2.1): Calculate the vehicle's heading angle θ(t) at time t;

[0100] The heading angle θ(t) is the coordinate axis x v The angle between the coordinate axis and the Y-axis is calculated as follows, with left deviation being positive and right deviation being negative:

[0101]

[0102]

[0103] Then at time t, x v The angle between the coordinate axis and the X-axis is: ;

[0104] Step (2.2): Calculate the coordinates of the dual laser rangefinder at time t;

[0105] The calculation formula is as follows:

[0106]

[0107] in, Let x be the x-coordinate of the laser spot on the laser receiver panel of laser rangefinder A at time t. Let x be the x-coordinate of the laser spot on the laser receiver panel of laser rangefinder B at time t;

[0108] Calculate the coordinates of the vehicle's physical center V at time t using the following formula:

[0109]

[0110] The transformation matrix from the vehicle coordinate system to the map coordinate system is:

[0111]

[0112] Then, the coordinates of the left front wheel of the AGV at time t in the map coordinate system are:

[0113]

[0114] The coordinates of the right front wheel at time t in the map coordinate system are:

[0115]

[0116] The coordinates of the left rear wheel at time t in the map coordinate system are:

[0117]

[0118] The coordinates of the right rear wheel at time t in the map coordinate system are:

[0119]

[0120] Where D is the vertical distance from the vehicle's physical center V to the line connecting the two laser rangefinders;

[0121] Step (3), turning radius analysis;

[0122] like Figure 5 As shown, the AGV pose at times t and t+1 changes from the position after... and The straight lines form the following equation:

[0123]

[0124] Then, the R of the vehicle's rotation center at times t and t+1 is obtained. (t) The coordinates are as follows:

[0125]

[0126] Real-time turning radius The expression is as follows:

[0127]

[0128] The real-time turning radius is determined by the radius analysis unit. Compare with the preset threshold thr, if If this condition is met for several consecutive sampling cycles (e.g., 5 sampling cycles, sampling cycle = 1 / the measurement frequency of the laser rangefinder), then the current driving trajectory of the vehicle is determined to be a stable straight line, the steering wheel direction does not need to be adjusted, and the calibration is completed; proceed directly to the following step (5).

[0129] like Or, at least one period within several consecutive sampling periods (e.g., 5 sampling periods) does not meet the requirement. If the condition is met, it is determined that the vehicle has a directional deviation and proceeds to the following step (4).

[0130] Step (4): Automatic compensation of steering wheel angle;

[0131] like Figure 6 As shown, based on the vehicle pose calculated in step (2), the rotation center coordinates and turning radius obtained in step (3), the angle compensation of the four steering wheels is determined to achieve the following angle compensation;

[0132] Step (4.1), calculate the deflection angle;

[0133] At time t+1, the steering wheel and R (t+1) The slope of the line in the map coordinate system is:

[0134]

[0135] At time t+1, the angle between the steering wheel and the positive Y-axis is:

[0136]

[0137] The steering wheel deflection angle at time t+1 is:

[0138]

[0139] Then, the angle value of the steering wheel after compensation at time t+1 is:

[0140]

[0141] in, The actual angle value of the steering wheel obtained by the motor driver at time t.

[0142] Single wheel deflection angle calculation, taking the right front wheel as an example.

[0143] As we know from the previous information, the coordinates of the four wheels of the vehicle in the map coordinate system are as follows. Taking the right front wheel as an example, the wheel deflection angle is calculated as shown in the figure. At time t+1, the right front wheel and R... (t+1) The slope of the line in the map coordinate system is:

[0144]

[0145] Vector at time t+1 Angle with the positive y-axis (Default: left is positive, right is negative) is:

[0146]

[0147] Then at time t+1, the right front wheel deflection angle for:

[0148]

[0149] The theoretical value after compensation for the right front wheel is:

[0150]

[0151] in, Let t be the actual angle of the right front wheel;

[0152] Calculation of compensation values ​​for the other three rounds:

[0153] Compensation amount for the left front wheel The calculation is as follows:

[0154]

[0155]

[0156]

[0157]

[0158] compensation amount of the left rear wheel The calculation is as follows:

[0159]

[0160]

[0161]

[0162]

[0163] Right rear wheel compensation amount The calculation is as follows:

[0164]

[0165]

[0166]

[0167]

[0168] Step (4.2), compensation value filtering;

[0169] Step (4.2), compensation value filtering;

[0170] To prevent abnormal offset calculations due to factors such as slippage, abnormal calculated values ​​need to be filtered out as follows:

[0171]

[0172] If the above conditions are met, proceed to step (4.3) below to perform angle compensation; otherwise, it should be determined that there is serious slippage, delete the current calculation data and proceed to step (2).

[0173] Step (4.3), closed-loop iterative compensation;

[0174] After the steering wheel adjustment is completed, the actual angle is fed back to the control unit;

[0175] The angle compensation unit's adjustment accuracy is verified using the following formula:

[0176]

[0177] in, This is the actual angle of the adjusted steering wheel;

[0178] If the above formula is true, the adjustment of the wheel is deemed valid; otherwise, return to step (4.1) to recalculate the compensation amount and adjust again; after the adjustment of the four steering wheels is completed, return to step (2).

[0179] Step (5), error detection and secondary calibration;

[0180] like Figure 7 As shown, after the conventional error compensation in the straight-ahead direction is completed, special installation errors such as "inward gait" and "outward gait" are further identified and corrected. These errors are usually difficult to detect when driving straight. Specifically, they include...

[0181] Step (5.1), 90-degree synchronous rotation control;

[0182] The control module controls the four steering wheels to rotate synchronously by 90 degrees (either left or right, with left rotation as the default), with a rotational angular velocity ≤30° / s, ensuring that the four steering wheels rotate at the same angle.

[0183] During rotation, the control unit collects the steering wheel angle data fed back by the motor driver in real time. When the steering wheel angle (taking the right front wheel as an example) is sampled continuously for 2 seconds and meets the requirements... The steering wheel is then judged to be in position.

[0184] Step (5.2), Lateral translation test;

[0185] Control the vehicle to travel laterally (originally along the X-axis) at a speed v (0.3m / s-0.5m / s), and travel a distance ≥ S (5m).

[0186] During the driving process, repeat steps (2) and (3) for pose detection and turning radius calculation;

[0187] If during the translation process If the vehicle does not exhibit "inward" or "outward" deviations, the calibration is complete; if it does, the calibration is complete. If the error is "inward" or "outward", proceed to step (4) to calculate the angle offset. After angle compensation, proceed to step (2); until the calculation results show an error after several consecutive calculations (e.g., 5 times) during the translation process. If the second calibration is successful, proceed to the following steps (5.3).

[0188] Step (5.3): Consolidation and traceability of calibration results;

[0189] After the second calibration is completed, the control unit saves the following data to the vehicle storage unit (supports no data loss when power is off), including the initial angle of each steering wheel, the final compensation amount, the calibration time, and the trajectory data of the straight / translation test;

[0190] Generate a calibration report, which includes information such as whether the calibration is qualified, error type, compensation details, and test parameters. The report can be exported to a host computer via an Ethernet interface.

[0191] The control unit writes the final compensation amount into the parameter register of the steering wheel drive module. This compensation amount is automatically loaded when the vehicle is driving normally to ensure driving accuracy.

[0192] Another embodiment of this application provides a computing device including a memory and a processor, wherein the memory stores a computer program, and the processor executes the computer program to implement the steps of the AGV four-steering wheel dynamic compensation method.

[0193] Another embodiment of this application provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the steps of the AGV four-steering wheel dynamic compensation method.

[0194] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. For the systems disclosed in the embodiments, since they correspond to the methods disclosed in the embodiments, the descriptions are relatively simple; relevant parts can be referred to the method section.

[0195] The above description of the embodiments is only for the purpose of helping to understand the method and core ideas of this application; at the same time, 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. The content of this specification should not be construed as a limitation of this application.

Claims

1. An automatic calibration system for four steering wheels of an AGV, characterized in that, It consists of the following modules; Vehicle-side equipment includes at least two sets of sensors mounted parallel to each other at the front of the vehicle; Fixed-end equipment, including a receiving panel and a coordinate calibration module; The coordinate calibration module is used to establish a test plane coordinate system with the horizontal center line of the receiving panel as the X-axis and the direction of the vehicle's front as the positive Y-axis. The origin O of the coordinate system is the geometric center of the receiving panel. The control unit receives sensor detection data and light spot coordinate data to perform vehicle pose calculation, trajectory analysis, and dynamic adjustment of steering wheel angle. It interacts in real time with vehicle-side equipment, fixed-side equipment, and steering wheel drive module, and has built-in pose calculation unit, trajectory fitting unit, radius analysis unit, dynamic compensation calculation unit, and rotation detection unit; the dynamic compensation calculation unit is used to perform angle compensation calculation and a method to eliminate special errors through 90-degree rotation and translation detection.

2. The AGV four-steering wheel automatic calibration system according to claim 1, characterized in that, The sensor is a laser rangefinder. Two sets of laser rangefinders are located at the front of the vehicle, with a distance of L between them and the laser emission direction is parallel to the longitudinal axis of the vehicle.

3. The AGV four-steering wheel dynamic compensation method applying the AGV four-steering wheel automatic calibration system as described in claim 2, characterized in that, Includes the following steps, Step (1), Initialization; Step (2): Real-time detection of vehicle position and posture; The control unit is based on the synchronous operation of two sets of laser rangefinders to collect data. Time laser rangefinder Distance collected Laser rangefinder Distance collected Simultaneously, it acquires data through the laser receiving panel. The laser rangefinder's spot coordinates Laser rangefinder Light spot coordinates The pose calculation unit calculates the vehicle's position based on the above data. Real-time pose of the vehicle at any given moment, including the coordinates of the vehicle's center point. The angle between the vehicle's longitudinal axis and the y-axis of the map coordinate system ; Step (3), turning radius analysis; The AGV pose at times t and t+1 is changed by... and The straight lines form the following equation: Then, the R of the vehicle's rotation center at times t and t+1 is obtained. (t) The coordinates are as follows: Real-time turning radius The expression is as follows: The real-time turning radius is determined by the radius analysis unit. Compare with the preset threshold thr, if If this condition is met for several consecutive sampling periods, the current driving trajectory of the vehicle is determined to be a stable straight line, the steering wheel direction does not need to be adjusted, and the calibration is completed; proceed directly to the following step (5). like Or, at least one period in several consecutive sampling periods does not meet the requirement. If the condition is met, it is determined that the vehicle has a directional deviation and proceeds to the following step (4). Step (4): Automatic compensation of steering wheel angle; Based on the vehicle pose calculated in step (2), the rotation center coordinates and turning radius obtained in step (3), the angle compensation of the four steering wheels is determined to achieve the following angle compensation. Step (5), error detection and secondary calibration; After the routine error compensation in the straight direction is completed, further identify and correct the installation errors of the inward and / or outward octagonal positions.

4. The AGV four-steering wheel dynamic compensation method according to claim 3, characterized in that, In step (1) described above, Place the four-steering wheel AGV at a preset distance directly in front of the laser receiving panel, ensuring that the lasers from both sets of laser rangefinders can be projected onto the laser receiving panel; start the AGV four-steering wheel automatic calibration system, calibrate the test plane coordinate system through the coordinate calibration module, and enter the known parameters.

5. The AGV four-steering wheel dynamic compensation method according to claim 3, characterized in that, Step (2) includes the following steps: (2.1) Calculate the vehicle's heading angle θ(t) at time t; The heading angle θ(t) is the coordinate axis x v The angle between the coordinate axis and the Y-axis is calculated as follows, with left deviation being positive and right deviation being negative: Then at time t, x v The angle between the coordinate axis and the X-axis is: ; Step (2.2): Calculate the coordinates of the dual laser rangefinder at time t; The calculation formula is as follows: in, Let x be the x-coordinate of the laser spot on the laser receiver panel of laser rangefinder A at time t. Let x be the x-coordinate of the laser spot on the laser receiver panel of laser rangefinder B at time t; Calculate the coordinates of the vehicle's physical center V at time t using the following formula: The transformation matrix from the vehicle coordinate system to the map coordinate system is: Where D is the vertical distance from the vehicle's physical center V to the line connecting the two laser rangefinders.

6. The AGV four-steering wheel dynamic compensation method according to claim 3, characterized in that, Step (4) includes, Step (4.1), calculate the deflection angle; At time t+1, the steering wheel and R (t+1) The slope of the line in the map coordinate system is: At time t+1, the angle between the steering wheel and the positive Y-axis is: The steering wheel deflection angle at time t+1 is: Then, the angle value of the steering wheel after compensation at time t+1 is: in, The actual angle value of the steering wheel obtained by the motor driver at time t; Step (4.2), compensation value filtering; To prevent abnormal offset calculations due to factors such as slippage, abnormal calculated values ​​need to be filtered out as follows: If the above conditions are met, proceed to step (4.3) below to perform angle compensation; otherwise, it should be determined that there is serious slippage, delete the current calculation data and proceed to step (2). Step (4.3), closed-loop iterative compensation; After the steering wheel adjustment is completed, the actual angle is fed back to the control unit; The angle compensation unit's adjustment accuracy is verified using the following formula: in, This is the actual angle of the adjusted steering wheel; If the above formula is true, the adjustment of the wheel is deemed valid; otherwise, return to step (4.1) to recalculate the compensation amount and adjust again; after the adjustment of the four steering wheels is completed, return to step (2).

7. The AGV four-steering wheel dynamic compensation method according to claim 3, characterized in that, The step (5) includes step (5.1), 90-degree synchronous rotation control; The control module controls the four steering wheels to rotate synchronously by 90 degrees, with a rotational angular velocity ≤30° / s, ensuring that the four steering wheels rotate at the same angle. During rotation, the control unit collects the steering wheel angle data fed back by the motor driver in real time. When the steering wheel angle is continuously sampled for several seconds and meets the requirements... Determine when the steering wheel has rotated to the correct position; Step (5.2), Lateral translation test; Control the vehicle to travel laterally at a speed v, with a travel distance ≥ S; During the driving process, repeat steps (2) and (3) for pose detection and turning radius calculation; If during the translation process This indicates that the vehicle has no inward or outward toeing error, and the calibration is complete; if... If thr is the turning radius threshold, it indicates the presence of inward and / or outward yaw errors. Proceed to step (4) to calculate the angle offset. After angle compensation, proceed to step (2). Continue until the calculation results are consistent during the translation process. If the second calibration is successful, proceed to the following steps (5.3). Step (5.3): Consolidation and traceability of calibration results; After the second calibration is completed, the control unit saves the following data to the vehicle storage unit, including the initial angle of each steering wheel, the final compensation amount, the calibration time, and the trajectory data of the straight / translation test; Generate a calibration report, which includes information such as whether the calibration is qualified, error type, compensation details, and test parameters. The report can be exported to a host computer via an Ethernet interface. The control unit writes the final compensation amount into the parameter register of the steering wheel drive module. This compensation amount is automatically loaded when the vehicle is driving normally to ensure driving accuracy.

8. A computer device comprising one or more processors and a storage device, characterized in that: The storage device stores one or more programs, which, when executed by the one or more processors, cause the one or more processors to implement the AGV four-steering wheel dynamic compensation method as described in any one of claims 3 to 7.

9. A computer-readable storage medium, characterized in that: It stores a computer-executable program that, when executed by a processor, implements the AGV four-steering wheel dynamic compensation method as described in any one of claims 3 to 7.

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