Dual-mode steering cooperative control method and system for five-axis heavy-load AGV

Abstract

The invention discloses a dual-mode steering cooperative control method and system for a five-axis heavy-load AGV, and the method comprises the following steps: obtaining the state information of the five-axis heavy-load AGV, including the vehicle speed, the path trajectory curvature and the obstacle distance; according to the obtained state information, a scene working condition is judged, a five-axis heavy-load AGV steering mode is decided according to the scene working condition, and a steering mode switching command is sent to a bottom layer controller; the steering mode comprises a pivot steering mode and a rear wheel active coordination steering mode; the bottom layer controller is used for controlling a hub motor and a steering motor; the bottom layer controller calculates the linear speed and the angular speed required by each wheel of the five-axis heavy-load AGV in the corresponding steering mode, and motion parameters are generated; the motion parameters are converted into reference control quantities to be sent to a bottom layer controller, the bottom layer controller adjusts the corresponding motor rotating speed in real time through IMU feedback and a PID control method, and the five-axis heavy-load AGV is driven to conduct steering motion coordination control.

Description

Technical Field

[0001] The present invention belongs to the field of automatic guided vehicle (AGV) control, and specifically relates to a dual-mode steering coordinated control method and system for a five-axis heavy-load AGV, which is suitable for multi-axis vehicle motion control integrating an in-situ steering mode and a rear-wheel active coordinated steering mode. Background Art

[0002] Due to the harsh environment inside the RoRo ship and the small space for stacking vehicles, high precision is required for the transfer vehicles. Therefore, the use of automatic guided vehicles (AGVs) instead of manual cargo transfer has gradually become the mainstream, which is of great significance to the construction of green, intelligent and unmanned ports.

[0003] The current technology has the following defects that need to be solved:

[0004] 1. Structural redundancy problem: Existing in-situ steering technology generally adopts an all-wheel independent steering structure, which requires each wheel set to be equipped with a high-precision steering motor, causing the system mass to increase by more than 28% and the manufacturing cost to increase significantly;

[0005] 2. Mechanical coupling defects: Due to the special requirements of the ro-ro ship climbing condition, the rear wheel needs to be integrated with a large torque drive unit (load ratio> 60%). When the front wheel active steering mode is adopted, it is easy to cause yaw moment imbalance in the medium and low speed range (0.5-5m / s), resulting in a trajectory tracking error of more than 15mm;

[0006] 3. Lack of intelligent decision-making: The existing system lacks scenario-adaptive decision-making logic and relies on manual intervention in different steering scenario requirements. Summary of the invention

[0007] In order to solve the technical problems in the prior art such as complex structure of multi-wheel independent steering mechanism, high cost, easy imbalance of yaw moment, large trajectory tracking error, rough steering mode switching logic, etc., the present invention provides a dual-mode steering collaborative control method for a five-axis heavy-load AGV, which realizes the in-situ steering function in low-speed scenarios and low-slip motion control in medium and high-speed scenarios through an Ackerman geometry correction model, a differential drive kinematic model, a five-axis wheel differential collaborative control and a scenario decision method.

[0008] The objective of the present invention is achieved through the following technical solutions:

[0009] As a first aspect of the present invention, a dual-mode steering coordinated control method for a five-axis heavy-load AGV is provided, wherein the five-axis heavy-load AGV is a five-axis ten-wheel structure, wherein the first, second, third, and fourth axes of the five-axis heavy-load AGV are all front axes, and the first to fourth axes use fixed direction wheels, which are independently driven by separate hub motors; the fifth axis of the five-axis heavy-load AGV is a rear axis, and the fifth axis is equipped with a steering motor for driving the rear wheels to adjust the steering angle; characterized in that the dual-mode steering coordinated control method comprises the following steps:

[0010] S1. Obtain the status information of the five-axis heavy-load AGV, including vehicle speed v, path trajectory curvature k, and obstacle distance d;

[0011] S2. According to the status information obtained in step S1, the scene condition is determined, the steering mode of the five-axis heavy-duty AGV is determined according to the scene condition, and the steering mode switching command is sent to the bottom controller; the steering mode includes the in-situ steering mode and the rear wheel active coordinated steering mode; the bottom controller is used to control the wheel hub motor and the steering motor;

[0012] S3. The bottom controller calculates the linear velocity and angular velocity required for each wheel of the five-axis heavy-duty AGV in the corresponding steering mode according to the steering mode switching command sent in step S2 and the path trajectory curvature information of the path planned in step 1, and generates motion parameters;

[0013] S4. Convert the motion parameters generated in step S3 into reference control quantities and send them to the underlying controller. The underlying controller uses IMU feedback and PID control method to adjust the corresponding motor speed in real time to drive the five-axis heavy-load AGV to coordinate steering motion control.

[0014] Furthermore, the step S2 comprises:

[0015] S21. The vehicle speed v and the path trajectory curvature k are integrated to determine the scene conditions of the five-axis heavy-duty AGV, wherein the scene conditions include low-speed scene conditions and medium-high-speed scene conditions;

[0016] S22. Make a decision on the steering mode of the five-axis heavy-load AGV:

[0017] If the five-axis heavy-load AGV is in a low-speed scenario, the five-axis heavy-load AGV is determined to enter the on-site turning mode, and a command to switch the on-site turning mode is sent to the underlying controller;

[0018] If the five-axis heavy-load AGV is in a medium-high speed scenario, the five-axis heavy-load AGV is decided to enter the rear-wheel active coordinated steering mode, and a rear-wheel active coordinated steering mode switching command is sent to the underlying controller;

[0019] When the distance d to the obstacle is less than the safety threshold, it is decided that the five-axis heavy-load AGV enters the active rear-wheel coordinated steering mode and sends a command to switch to the active rear-wheel coordinated steering mode to the lower-level controller.

[0020] Further, the scenario condition determination in step S21 is as follows:

[0021] When the vehicle speed v < 0.5 m / s and the path curvature κ > 1.0 m -1 , the five-axis heavy-load AGV is in a low-speed scenario condition;

[0022] When the vehicle speed 0.5 m / s < v 5.6 m / s (20 km / h) and the path curvature κ < 1.0 m -1 , the five-axis heavy-load AGV is in a medium-high speed scenario.

[0023] Further, in step S3, when the lower-level controller receives the in-situ steering mode switching command, the motion parameter calculation process is as follows:

[0024] Set the steering angle of the fifth-axis wheel of the five-axis heavy-load AGV to 0°;

[0025] Set the in-situ steering yaw angular velocity ω to 0.3 rad / s;

[0026] According to the path steering direction of the planned path, set the wheels close to the path direction to rotate forward and the wheels away from the path steering direction to rotate backward;

[0027] The speed v of the wheel close to the steering direction neari = , the speed v of the wheel away from the steering direction fari =- , where i represents the i-th axis of the five-axis heavy-load AGV and W represents the wheelbase of the same axis;

[0028] Calculate the angular velocity ω of each wheel i = 2Vi / W, and then convert the speed to the motor speed n i , and send an execution command to the lower-level controller;

[0029] Verify the centroid motion of the five-axis heavy-load AGV at this time through speed field synthesis. The verification formula is:

[0030] Translation balance verification: ;

[0031] Rotation balance verification:

[0032] Among them, is the wheel speed, refers to the position vector between the centroid and the moving point, and the equivalent moment of inertia I = , W represents the coaxial wheelbase; when a wheel fails, its coaxial wheel compensates the wheel speed output to maintain the total angular momentum unchanged.

[0033] Furthermore, in step S3,

[0034] When the bottom-level controller receives the rear wheel active coordinated steering mode switching command, the motion parameter calculation process is:

[0035] According to the Ackerman steering principle, the rear wheel steering angle δ is calculated from the total wheelbase L, the track width W and the current minimum turning radius R; the minimum turning radius R is represented by the current path curvature κ, R=1 / κ; at the same time, the track width W is ignored;

[0036] The rear wheel steering angle calculation formula is simplified to:

[0037]

[0038] Where L is the total wheelbase, κ is the curvature of the current path;

[0039] Introduce the cubic correction formula δ'=δ+kδ³

[0040] Where k is the slip suppression coefficient; from this, the rear wheel steering angle δ' is obtained;

[0041] The speeds of other driving wheels are dynamically distributed according to their distances to the steering center O:

[0042] For the outer wheels, = (1+di*κ);

[0043] For the inner wheel, = (1-di*κ)

[0044] in, is the lateral offset between the i-th wheel and the steering center O, κ is the curvature radius of the current path, is the wheel speed, is the reference speed, and R is the theoretical turning radius.

[0045] Furthermore, in step S4, the motor speed is obtained in real time by using the motor sensor and IMU and fed back to the bottom controller. The bottom controller uses the PID control method to adjust the P and I parameters before mass production of the product, and adjusts the hub motor speed and the steering motor speed according to the hub motor speed difference and the rear wheel angle difference Δδ, so that the control amount tracks the reference control amount.

[0046] As a second aspect of the present invention, a dual-mode steering coordinated control system for a five-axis heavy-duty AGV is provided, which is used to implement the dual-mode steering coordinated control method of the present invention, and the dual-mode steering coordinated control system includes:

[0047] The status information detection module is used to obtain the status information of the five-axis heavy-load AGV, including vehicle speed v, path trajectory curvature k, and obstacle distance d;

[0048] The decision module is used to determine the scene conditions according to the status information of the five-axis heavy-load AGV, decide the steering mode of the five-axis heavy-load AGV according to the scene conditions, and send the steering mode switching command to the bottom controller;

[0049] The bottom-level controller is used to calculate the linear velocity and angular velocity required for each wheel of the five-axis heavy-duty AGV in the corresponding steering mode according to the received steering mode switching command and the status information of the five-axis heavy-duty AGV, generate motion parameters as reference control quantities, adjust the speed of the steering motor and the hub motor, and realize coordinated control of the steering motion.

[0050] Furthermore, the state information detection module includes:

[0051] Wheel motor encoder, used to obtain the speed of the five-axis heavy-load AGV in real time;

[0052] The path planning module is used to output the planned path and obtain the path trajectory curvature;

[0053] Obstacle perception module, used to detect obstacle distance.

[0054] Furthermore, the bottom-level controller includes a motion calculation module for calculating the linear velocity and angular velocity required for each wheel of the five-axis heavy-load AGV in the corresponding steering mode to generate motion parameters.

[0055] Compared with the prior art, the technical effects and advantages of the present invention are:

[0056] Aiming at the requirements of steering motion control effect and steering function cost, the present invention provides a dual-mode steering cooperative control method for a five-axis heavy-duty AGV. The method can switch the steering motion control mode according to the current scene of the vehicle, and use different motion control algorithms to realize the in-situ steering function and requirements in the static (extremely low speed) scene. In the medium and low speed scene, the rear wheel active cooperative steering function is used to realize the steering at small curvature and reduce the lateral error. At the same time, the method reduces the number of steering motors, saves manufacturing costs and transportation costs, and meets the requirements of green and intelligent port transportation in my country. BRIEF DESCRIPTION OF THE DRAWINGS

[0057] Figure 1 This is a schematic diagram of the structure of the five-axis heavy-load AGV described in Example 1 of the present invention;

[0058] Figure 2 This is a flow chart of the dual-mode steering cooperative control method of the five-axis heavy-load AGV described in Example 1 of the present invention;

[0059] Figure 3 The kinematic model of the in-situ turning mode described in Example 1 of the present invention;

[0060] Figure 4 The kinematic model of the active coordinated steering mode described in Example 1 of the present invention;

[0061] Figure 5 This is a block diagram of the composition principle of a dual-mode steering cooperative control system for a five-axis heavy-duty AGV according to Embodiment 2 of the present invention;

[0062] In the figure:

[0063] 1-first axis; 2-second axis; 3-third axis; 4-fourth axis; 5-fifth axis; 6-wheel hub motor; 7-steering motor; 8-rear wheel; 9-clamping mechanism. DETAILED DESCRIPTION

[0064] The present invention is further described below in conjunction with the accompanying drawings and embodiments.

[0065] Example 1

[0066] This embodiment is a dual-mode steering cooperative control method for a five-axis heavy-duty AGV, wherein the five-axis heavy-duty AGV is a five-axis ten-wheel structure, and all ten wheels are wheel hub motors that can independently control torque; the first, second, third, and fourth axes 1-4 of the five-axis heavy-duty AGV are front axes, and the first to fourth axes use fixed direction wheels, and the first to fourth axes are independently driven by separate wheel hub motors 6; the fifth axis 5 of the five-axis heavy-duty AGV is the rear axis, and the fifth axis is equipped with a steering motor 7, which drives the rear wheel 8 to adjust the steering angle δ, thereby increasing the reliability of the five-axis heavy-duty AGV during steering and preventing excessive trajectory tracking errors and lateral slippage;

[0067] The specific operation steps of the method are as follows:

[0068] S1. Get the status information of the five-axis heavy-load AGV:

[0069] The status information of the five-axis heavy-duty AGV is obtained through the status information detection module of the five-axis heavy-duty AGV, including: the wheel hub motor encoder obtains the vehicle speed v (m / s) in real time, and the path planning module outputs the planned path and obtains the path trajectory curvature k (m -1 ), the obstacle sensing module detects the obstacle distance d (m); in this embodiment, the obstacle safety threshold is set to 2m in the obstacle sensing module.

[0070] S2. Based on the status information obtained in step S1, the decision-making module determines the scene working conditions, decides the steering mode of the five-axis heavy-load AGV according to the scene working conditions, and sends a steering mode switching command to the underlying controller; the steering modes include in-situ steering mode and rear-wheel active coordinated steering mode; the underlying controller is used to control the hub motor 6 and the steering motor 7.

[0071] S21. The decision-making module fuses the vehicle speed v and the path trajectory curvature k to determine the scene working conditions of the five-axis heavy-load AGV, including:

[0072] When the vehicle speed v < 0.5 m / s and the path curvature κ > 1.0 m -1 , the five-axis heavy-load AGV is in a low-speed scene working condition;

[0073] When the vehicle speed 0.5 m / s < v 5.6 m / s (20 km / h) and the path curvature κ < 1.0 m -1 , the five-axis heavy-load AGV is in a medium-high speed scene;

[0074] S22. If the five-axis heavy-load AGV is in a low-speed scene working condition, the decision-making module decides that the five-axis heavy-load AGV enters the in-situ steering mode, and the decision-making module sends an in-situ steering mode switching command to the controllers of the hub motor 6 and the steering motor 7 respectively: If the five-axis heavy-load AGV is in a medium-high speed scene working condition, the decision-making module decides that the five-axis heavy-load AGV enters the rear-wheel active coordinated steering mode, and the decision-making module sends a rear-wheel active coordinated steering mode switching command to the controllers of the hub motor 6 and the steering motor 7 respectively; when the obstacle distance d < the safety threshold (2 m in this embodiment), regardless of the current mode, the decision-making module decides that the five-axis heavy-load AGV enters the rear-wheel active coordinated steering mode.

[0075] S3. The underlying controller calculates the linear velocity and angular velocity required for each wheel of the five-axis heavy-load AGV in the corresponding steering mode according to the steering mode switching command sent in step S2 and the path trajectory curvature information of the path planned in step 1, and generates motion parameters.

[0076] S31. When the underlying controller receives the in-situ steering mode switching command, the calculation process of the motion calculation module is as follows:

[0077] First, set the steering angle of the fifth-axis wheel to 0°, and since the current speed is extremely low, the speed is approximately 0;

[0078] Set the in-situ steering yaw angular velocity ω to 0.3 rad / s;

[0079] According to the path steering direction of the planned path, set the wheel close to the path direction to rotate forward, and set the wheel far from the path steering direction to rotate backward; the speed v close to the steering direction neari = , the speed away from the turning direction v fari =- , where i represents the i-th axis of the five-axis heavy-load AGV, and W represents the coaxial wheelbase (m).

[0080] Calculate the angular velocity ω of each wheel i =2Vi / W, and then convert the speed into motor speed n i (r / min), sends an execution command to the underlying controller; because the speed is very low and the road condition remains good, the influence of tire slip is ignored and no speed compensation is performed for lateral slip;

[0081] The velocity field synthesis verifies the centroid movement of the five-axis heavy-duty AGV at this time, and the verification formula is:

[0082] (Translational balance), (Rotational balance)

[0083] in, Refers to the position vector between the center of mass and the moving point. The total translational velocity automatically returns to zero, and the equivalent moment of inertia I= , when a wheel fails, its coaxial wheel compensates the wheel speed output to maintain the total angular momentum unchanged;

[0084] S32. When the bottom controller receives the rear wheel active coordinated steering mode switching command, the calculation process of the motion calculation module is:

[0085] According to the Ackerman steering principle, the rear wheel steering angle δ is calculated from the total wheelbase L, the track width W and the current minimum turning radius R. Since the minimum turning radius R is difficult to obtain, the minimum turning radius R is represented by the current path curvature κ, R=1 / κ. At the same time, the track width W is smaller than the turning radius R and can be ignored.

[0086] Therefore, the rear wheel steering angle calculation formula is simplified to:

[0087]

[0088] Where L is the total wheelbase, κ is the curvature of the current path;

[0089] The cubic correction formula δ'=δ+kδ³ (k=0.15 is the slip suppression coefficient) is introduced to compensate for the tire side slip effect during high-speed steering, and the rear wheel steering angle δ' is obtained. It should be noted that due to the active rear wheel steering, the steering direction and steering angle of the five-axis heavy-duty AGV should be in the opposite direction, such as Figure 4 As shown;

[0090] Since other axle wheels are not equipped with steering motors, differential compensation is required for other wheels. The speeds of other driving wheels are dynamically distributed according to their distances to the steering center O:

[0091] For the outer wheels, = (1+di*κ);

[0092] For the inner wheel, = (1-di*κ)

[0093] in, is the lateral offset between the i-th wheel and the steering center O, κ is the curvature radius of the current path, is the wheel speed, is the reference speed, and R is the theoretical turning radius. Also, because the theoretical turning radius is difficult to obtain, the offset here is approximately simplified to half of the wheelbase, that is, W / 2.

[0094] S4. The motion parameters generated in step S3 are converted into reference control quantities. The underlying controller uses IMU feedback and PID control method to adjust the corresponding motor speed in real time to drive the five-axis heavy-load AGV to coordinate steering motion control:

[0095] The motor speed is obtained in real time by using motor sensors and IMU, and then fed back to the underlying controller. The underlying controller uses the PID control method to adjust parameters such as P and I before mass production, and adjusts the hub motor speed and steering motor speed according to the hub motor speed difference and the rear wheel steering angle difference Δδ, so that the control quantity accurately tracks the reference control quantity. When the steering mode is switched, the steering angle command δ smoothly transitions through linear mapping, and the transition time t=0.5s is used to avoid the center of mass shift caused by sharp turns.

[0096] Preferably, the five-axis heavy-duty AGV is mainly used for transporting cars, and the clamping mechanism 9 is used to clamp the car to be transported. When clamping, the left and right are centered, and the center of mass is located on the center line of the five-axis heavy-duty AGV. However, due to the uncertainty of the model and type of the clamped car, its position on the center line is uncertain. Due to the particularity of the center of mass position, when realizing the in-situ steering function, the five-axis heavy-duty AGV is not affected by the position of the center of mass on the center line.

Claims

1. A dual-mode steering coordinated control method for a five-axis heavy-load AGV, wherein the five-axis heavy-load AGV is a five-axis ten-wheel structure, wherein the first, second, third, and fourth axes of the five-axis heavy-load AGV are all front axes, and the first to fourth axes use fixed direction wheels, which are independently driven by separate hub motors; the fifth axis of the five-axis heavy-load AGV is a rear axis, and the fifth axis is equipped with a steering motor for driving the rear wheels to adjust the steering angle; characterized in that: The dual-mode steering coordinated control method comprises the following steps: S1. Obtain the status information of the five-axis heavy-load AGV, including vehicle speed v, path trajectory curvature k, and obstacle distance d; S2. According to the status information obtained in step S1, the scene condition is determined, the steering mode of the five-axis heavy-duty AGV is determined according to the scene condition, and the steering mode switching command is sent to the bottom controller; the steering mode includes the in-situ steering mode and the rear wheel active coordinated steering mode; the bottom controller is used to control the wheel hub motor and the steering motor; S3. The bottom controller calculates the linear velocity and angular velocity required for each wheel of the five-axis heavy-duty AGV in the corresponding steering mode according to the steering mode switching command sent in step S2 and the path trajectory curvature information of the path planned in step 1, and generates motion parameters; S4. Convert the motion parameters generated in step S3 into reference control quantities and send them to the underlying controller. The underlying controller uses IMU feedback and PID control method to adjust the corresponding motor speed in real time to drive the five-axis heavy-load AGV to coordinate steering motion control.

2. A dual-mode steering coordinated control method for a five-axis heavy-load AGV as claimed in claim 1, characterized in that: The step S2 comprises: S21. The vehicle speed v and the path trajectory curvature k are integrated to determine the scene conditions of the five-axis heavy-duty AGV, wherein the scene conditions include low-speed scene conditions and medium-high-speed scene conditions; S22. Make a decision on the steering mode of the five-axis heavy-load AGV: If the five-axis heavy-load AGV is in a low-speed scenario, the five-axis heavy-load AGV is determined to enter the on-site turning mode, and a command to switch the on-site turning mode is sent to the underlying controller; If the five-axis heavy-load AGV is in a medium-high speed scenario, the five-axis heavy-load AGV is decided to enter the rear-wheel active coordinated steering mode, and a rear-wheel active coordinated steering mode switching command is sent to the underlying controller; When the obstacle distance d < the safety threshold, the five-axis heavy-load AGV is decided to enter the rear-wheel active coordinated steering mode, and a rear-wheel active coordinated steering mode switching command is sent to the underlying controller.

3. A dual-mode steering coordinated control method for a five-axis heavy-load AGV as claimed in claim 2, characterized in that: The scene condition determination condition in step S21 is: When the vehicle speed v<0.5m / s and the path curvature κ>1.0m -1 , the five-axis heavy-load AGV is in a low-speed scenario; When the vehicle speed is 0.5 m / s < v < 5.6 m / s (20 km / h) and the path curvature κ < 1.0 m -1 , the five-axis heavy-load AGV is in the medium-high speed scenario.

4. A dual-mode steering coordinated control method for a five-axis heavy-load AGV as claimed in claim 1, characterized in that: In step S3, when the bottom-level controller receives the on-site steering mode switching command, the motion parameter calculation process is: Set the steering angle of the fifth-axis wheel of the five-axis heavy-load AGV to 0°; Set the in-situ steering yaw angular velocity ω to 0.3rad / s; According to the path turning direction of the planned path, the wheels close to the path direction are set to forward rotation, and the wheels away from the path turning direction are set to reverse rotation; Wheel speed v in the direction of steering neari = , the speed away from the turning direction v fari =- , where i represents the i-th axis of the five-axis heavy-load AGV, and W represents the coaxial wheelbase; Calculate the angular velocity ω of each wheel i =2Vi / W, and then convert the speed into motor speed n i , issue execution commands to the underlying controller; The velocity field synthesis verifies the centroid movement of the five-axis heavy-duty AGV at this time, and the verification formula is: Translational balance verification: ; Rotational balance verification: ; in, is the wheel speed, Refers to the position vector between the center of mass and the moving point, equivalent moment of inertia I= , W represents the coaxial wheelbase; when a wheel fails, its coaxial wheel compensates the wheel speed output to maintain the total angular momentum unchanged.

5. The dual-mode steering coordinated control method for a five-axis heavy-load AGV according to claim 1, characterized in that: In the step S3, When the bottom-level controller receives the rear wheel active coordinated steering mode switching command, the motion parameter calculation process is: According to the Ackerman steering principle, the rear wheel steering angle δ is calculated from the total wheelbase L, the track width W and the current minimum turning radius R; the minimum turning radius R is represented by the current path curvature κ, R=1 / κ; at the same time, the track width W is ignored; The rear wheel steering angle calculation formula is simplified to: ； Where L is the total wheelbase, κ is the curvature of the current path; Introduce the cubic correction formula δ'=δ+kδ³; Where k is the slip suppression coefficient; from this, the rear wheel steering angle δ' is obtained; The speeds of other driving wheels are dynamically distributed according to their distances to the steering center O: For the outer wheels, = (1+di*κ); For the inner wheel, = (1-di*κ); in, is the lateral offset between the i-th wheel and the steering center O, κ is the curvature radius of the current path, is the wheel speed, is the reference speed, and R is the theoretical turning radius.

6. A dual-mode steering coordinated control method for a five-axis heavy-load AGV as claimed in claim 1, characterized in that: In step S4, the motor speed is obtained in real time by using the motor sensor and IMU, and fed back to the bottom controller. The bottom controller uses the PID control method to adjust the P and I parameters before mass production of the product, and adjusts the hub motor speed and the steering motor speed according to the hub motor speed difference and the rear wheel steering angle difference Δδ, so that the control amount tracks the reference control amount.

7. A dual-mode steering coordinated control system for a five-axis heavy-duty AGV, which is used to implement the dual-mode steering coordinated control method as described in any one of claims 1 to 6, characterized in that: The dual-mode steering cooperative control system comprises: The status information detection module is used to obtain the status information of the five-axis heavy-load AGV, including vehicle speed v, path trajectory curvature k, and obstacle distance d; The decision module is used to determine the scene conditions according to the status information of the five-axis heavy-load AGV, decide the steering mode of the five-axis heavy-load AGV according to the scene conditions, and send the steering mode switching command to the bottom controller; The bottom-level controller is used to calculate the linear velocity and angular velocity required for each wheel of the five-axis heavy-duty AGV in the corresponding steering mode according to the received steering mode switching command and the status information of the five-axis heavy-duty AGV, generate motion parameters as reference control quantities, adjust the speed of the steering motor and the hub motor, and realize coordinated control of the steering motion.

8. A dual-mode steering cooperative control system for a five-axis heavy-load AGV as claimed in claim 7, characterized in that: The state information detection module comprises: Wheel motor encoder, used to obtain the speed of the five-axis heavy-load AGV in real time; The path planning module is used to output the planned path and obtain the path trajectory curvature; Obstacle perception module, used to detect obstacle distance.

9. A dual-mode steering coordination control system for a five-axis heavy-load AGV as claimed in claim 7, characterized in that: The bottom-level controller includes a motion calculation module for calculating the linear velocity and angular velocity required for each wheel of the five-axis heavy-duty AGV in the corresponding steering mode to generate motion parameters.

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