Fault-tolerant control method for man-machine co-driving steer-by-wire system and related device

Abstract

The invention provides a man-machine co-driving steer-by-wire system fault-tolerant control method and a related device. The method comprises the following steps: constructing a driver-vehicle coupling model; constructing an outer-ring non-cooperative game model, setting a driver as a first participant, setting an intelligent driving system as a second participant, respectively distributing differential control targets for the first participant and the second participant, and defining control input and cost functions of the first participant and the second participant; an inner ring pursuit game is embedded in the outer ring non-cooperative game model to solve the conflict between performance and disturbance, and an inner and outer ring mixed game framework is obtained; and solving the equilibrium solution of the inner and outer ring mixed game framework to obtain the optimal control input of the first participant and the second participant, thereby realizing fault-tolerant control of the steer-by-wire system, effectively solving the control target difference and potential instruction conflict between the driver and the intelligent driving system in the man-machine co-driving scene, and improving the driving safety. The limitation of fault compensation and light target coordination in the prior art is solved.

Description

Technical Field

[0001] This application relates to the field of linear control technology, specifically to a fault-tolerant control method and related device for a human-machine co-driving steer-by-wire system. Background Technology

[0002] As a core platform for the implementation of intelligent driving technology, the steer-by-wire chassis, with its flexible controllability, provides a solid foundation for the deployment of various active safety control systems. Among them, the steer-by-wire system transmits steering signals via a bus, eliminating the mechanical connection between the steering wheel and the steering mechanism, thus decoupling them. This not only improves steering response speed and safety but also creates favorable conditions for the application of safety systems such as active front-wheel steering, especially meeting the technological development needs of human-machine co-driving. However, the high structural complexity of steer-by-wire systems, relying on the coordinated operation of numerous mechanical and electronic components, significantly increases the probability of system failure. Precise execution of steering function is a core prerequisite for safe vehicle operation; a malfunction in the steering system directly threatens the lives of passengers. Therefore, fault-tolerant control has become an indispensable key technology for steer-by-wire systems.

[0003] Existing steer-by-wire fault-tolerant control technologies primarily focus on functional compensation after a malfunction occurs, but fail to fully consider the core contradictions in human-machine co-driving scenarios, where the control objectives of the driver and the intelligent driving system are inherently different. This difference can easily lead to conflicting commands between the two parties, making it difficult for existing technologies to simultaneously ensure fault tolerance and meet the needs of different control entities. Consequently, this affects the stability and reliability of vehicle operation and fails to meet the high precision and high safety requirements for steering control in human-machine co-driving scenarios. Summary of the Invention

[0004] This application provides a fault-tolerant control method and related device for a human-machine co-driving steer-by-wire system, which can effectively resolve the differences in control objectives between the driver and the intelligent driving system and potential command conflicts in human-machine co-driving scenarios, and solve the limitations of fault compensation and light target coordination in the prior art.

[0005] A first aspect of this application provides a fault-tolerant control method for a human-machine co-driving steer-by-wire system, the method comprising:

[0006] Construct a driver-vehicle coupling model;

[0007] A non-cooperative game model for the outer loop is constructed, with the driver as the first participant and the intelligent driving system as the second participant. Differentiated control objectives are assigned to the first participant and the second participant respectively, and the control inputs and cost functions of both parties are defined.

[0008] An inner-loop chase-escape game is embedded in the outer-loop non-cooperative game model. The control target performance of the first participant is modeled as the first pursuer, and the corresponding fault disturbance is modeled as the first escapee. The control target performance of the second participant is modeled as the second pursuer, and the corresponding fault disturbance is modeled as the second escapee, thus obtaining a hybrid inner-loop game framework.

[0009] Solving the equilibrium solution of the inner and outer loop hybrid game framework yields the optimal control inputs for the first and second participants, enabling fault-tolerant control of the steer-by-wire system.

[0010] In one possible implementation, the driver-vehicle coupling model includes a system state vector, a control input vector, and a fault disturbance vector. The fault disturbance vector is used to simulate various fault scenarios of the steer-by-wire system. The expression of the driver-vehicle coupling model is as follows:

[0011] x(k+1)=Az(k)+B1u (1) (k)+B2u (2) (k)+B d d+w(k)

[0012] Where x(k+1) is the driver-vehicle system state vector at the next time step, x(k) is the driver-vehicle system state vector, A is the state matrix, B1 is the input matrix of the first participant, B2 is the input matrix of the second participant, and u (1) (k) represents the control input of the first participant to the driver-vehicle system, u (2) (k) represents the control input of the second participant to the driver-vehicle system, B d d represents the self-centering torque and friction torque of the steering system, and w(k) represents the bounded disturbance caused by steering motor failure and unmodeled dynamics.

[0013] In one possible implementation, the fault disturbance vector is calculated using a fault model, the expression of which is as follows:

[0014] τ s =ετ m +Δτ m ,

[0015] Where, τ s τ is the actual output torque of the motor, ε is the fault factor, and τ is the actual output torque of the motor. m For the steering motor torque, Δτ m This refers to the offset torque caused by the fault.

[0016] In one possible implementation, the outer-loop non-cooperative game model is constructed, with the driver as the first participant and the intelligent driving system as the second participant. Differentiated control objectives are assigned to the first and second participants respectively, and the control inputs and cost functions for both parties are defined. The expression of the inner-outer-loop hybrid game framework is as follows:

[0017]

[0018] i = 1, 2

[0019] Where, Δy (i) (k) represents the system output error, u (i) (k) is the control input, Q (i) R is the system output error weight matrix. (i) To control the input weight matrix, C (i) For the output matrix, and These are the lower and upper limits for system control inputs.

[0020] In one possible implementation, an inner-loop pursuit-escape game is embedded in the outer-loop non-cooperative game model. The control objective performance of the first participant is modeled as the first pursuer, and the corresponding fault disturbance is modeled as the first escapee. The control objective performance of the second participant is modeled as the second pursuer, and the corresponding fault disturbance is modeled as the second escapee. The expression of the inner-loop pursuit-escape game in the hybrid inner-loop game framework is as follows:

[0021]

[0022] stx(k+1)=Ax(k)+B1u (1) (k)+B2u (2) (k)+B d d+w (i) (k)

[0023] y (i) (k)=C (i) x(k)

[0024]

[0025] i = 1, 2

[0026] in, Let w be the cost function of the participants in the pursuit game. (i) (k) represents the system disturbance. and These represent the lower and upper limits of the system disturbance.

[0027] In one possible implementation, an inner-loop chase-escape game is embedded in the outer-loop non-cooperative game model. The control objective performance of the first player is modeled as the first pursuer, and the corresponding fault disturbance is modeled as the first escapee. The control objective performance of the second player is modeled as the second pursuer, and the corresponding fault disturbance is modeled as the second escapee. The resulting expression for the optimization problem of the first pursuer and the second pursuer in the inner-loop hybrid game framework is as follows:

[0028]

[0029] stx(k+1)=Ax(k)+B1u (1) (k)+B2u (2) (k)+B d d+w (i) (k)

[0030] y (i) (k)=C (i) x(k)

[0031]

[0032] in, For the cost function of the pursuer in a pursuit game, w (i)* (k) represents the optimal solution for the escapee.

[0033] In one possible implementation, an inner-loop chase-escape game is embedded in the outer-loop non-cooperative game model. The control objective performance of the first participant is modeled as the first pursuer, and the corresponding fault disturbance is modeled as the first escapee. The control objective performance of the second participant is modeled as the second pursuer, and the corresponding fault disturbance is modeled as the second escapee. The resulting expression for the optimization problem of the first and second escapees in the inner-loop hybrid game framework is as follows:

[0034]

[0035] stx(k+1)=Ax(k)+B1u (1) (k)+B2u (2) (k)+B d d+w (i) (k)

[0036] y (i) (k)=C (i) x(k)

[0037]

[0038] in, Let u be the cost function of the escapee in the pursuit game. (i)*(k) is the optimal solution for the pursuer.

[0039] In one possible implementation, solving for the equilibrium solution of the inner and outer loop hybrid game framework includes:

[0040] Perform initialization processing;

[0041] The optimal control input of the first participant and the optimal control input of the second participant at the previous time step;

[0042] Based on the initialization results, the saddle point solution of the inner loop chase-escape game is solved to obtain the optimal fault disturbance strategy of the first and second escapees.

[0043] Substitute the optimal fault disturbance strategy into the outer-loop non-cooperative game model to solve for the optimal control inputs of the first and second participants.

[0044] Repeat the initialization of the optimal control inputs of the first and second participants from the previous time step until the optimal fault disturbance strategy is substituted into the outer-loop non-cooperative game model. Solve for the optimal control inputs of the first and second participants until the difference between the optimal control inputs of two adjacent iterations is less than a preset threshold, and output the final equilibrium solution.

[0045] This example provides a fault-tolerant control method for a human-machine co-driving steer-by-wire system. First, a driver-vehicle coupled model is constructed, followed by an outer-loop non-cooperative game model. Then, an inner-loop pursuit-escape game is embedded within this outer-loop model. Finally, the equilibrium solution of this hybrid game framework is solved to obtain the optimal control input for both participants, achieving fault-tolerant control of the steer-by-wire system. By using a hybrid game framework that coordinates human-machine objectives in the outer loop and handles fault disturbances in the inner loop, this method effectively resolves the differences in control objectives and potential command conflicts between the driver and the intelligent driving system in human-machine co-driving scenarios, overcoming the limitations of fault compensation and light-objective coordination in existing technologies. Furthermore, it can cope with steering system faults, achieving fault-tolerant control without relying on precise fault information. Ultimately, while considering the needs of different control subjects, it ensures the stability and reliability of vehicle operation, meeting the high precision and high safety requirements for steering control in human-machine co-driving scenarios.

[0046] A second aspect of this application provides a fault-tolerant control device for a human-machine co-driving steer-by-wire system, the device comprising:

[0047] The first processing unit is used to construct the driver-vehicle coupling model;

[0048] The second processing unit is used to construct an outer-loop non-cooperative game model, setting the driver as the first participant and the intelligent driving system as the second participant, assigning differentiated control objectives to the first participant and the second participant respectively, and defining the control inputs and cost functions for both parties.

[0049] The third processing unit is used to embed an inner-loop chase-escape game into the outer-loop non-cooperative game model, modeling the control target performance of the first participant as the first pursuer and the corresponding fault disturbance as the first escapee; modeling the control target performance of the second participant as the second pursuer and the corresponding fault disturbance as the second escapee, thus obtaining a hybrid inner-loop game framework.

[0050] The control unit is used to solve the equilibrium solution of the inner and outer loop hybrid game framework, obtain the optimal control input of the first and second participants, and realize the fault-tolerant control of the steer-by-wire system.

[0051] A third aspect of this application provides a terminal including a processor, an input device, an output device, and a memory, wherein the processor, input device, output device, and memory are interconnected, wherein the memory is used to store a computer program, the computer program including program instructions, and the processor is configured to invoke the program instructions to execute the steps of the fault-tolerant control method for a human-machine co-driving steer-by-wire system as described in the first aspect of this application.

[0052] A fourth aspect of this application provides a computer-readable storage medium storing a computer program for electronic data exchange, wherein the computer program causes a computer to perform some or all of the steps described in the human-machine co-driving steer-by-wire system fault-tolerant control method of the first aspect of this application.

[0053] A fifth aspect of this application provides a computer program product, comprising a non-transitory computer-readable storage medium storing a computer program operable to cause a computer to perform some or all of the steps described in the fault-tolerant control method for a human-machine co-driving steer-by-wire system in the first aspect of this application. The computer program product may be a software installation package. Attached Figure Description

[0054] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art 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.

[0055] Figure 1 This application provides a schematic flowchart of a fault-tolerant control method for a human-machine co-driving steer-by-wire system. Figure 1 ;

[0056] Figure 2 This application provides a schematic flowchart of a fault-tolerant control method for a human-machine co-driving steer-by-wire system. Figure 2 ;

[0057] Figure 3 This application provides a schematic diagram of the overall structure of a fault-tolerant control device for a human-machine co-driving steer-by-wire system.

[0058] Figure 4 This application provides a schematic diagram of the structure of a terminal.

[0059] Figure label:

[0060] First processing unit-1, second processing unit-2, third processing unit-3, control unit-4. Detailed Implementation

[0061] 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.

[0062] The terms "first," "second," etc., in the specification, claims, and accompanying drawings of this application are used to distinguish different objects, not to describe a specific order. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or apparatus that includes a series of steps or units is not limited to the listed steps or units, but may optionally include steps or units not listed, or may optionally include other steps or units inherent to these processes, methods, products, or apparatuses.

[0063] In this application, the reference to "embodiment" means that a specific feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a mutually exclusive, independent, or alternative embodiment. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described in this application can be combined with other embodiments.

[0064] To better understand the fault-tolerant control method for the human-machine co-driving steer-by-wire system provided in this application embodiment, the scenarios in which this method is applied are briefly introduced below. The steer-by-wire chassis provides the vehicle with greater controllability margins. Differential power steering torque can be adjusted by adjusting the driving force rectangles on the left and right sides of the front axle to compensate for steering system malfunctions. However, since the direct yaw torque control system also needs to utilize the front axle differential torque to improve vehicle stability, and the differential torque controlling steering is opposite to the differential torque controlling stability, utilizing the front axle differential torque will affect the effectiveness of the direct yaw torque control. Furthermore, with the development of intelligent driving technology, the driver-vehicle should be considered as a whole. Especially in human-machine co-driving, the steering system will simultaneously execute commands from both the driver and the intelligent driving system. Therefore, the driver should also be included in the fault-tolerant control framework of the steer-by-wire system, especially considering situations where driver commands and intelligent driving system commands are inconsistent or even conflicting. Therefore, the fault-tolerant control of steer-by-wire in human-machine co-driving faces the problem of compensating for fault disturbances on one hand, and the problem of human-machine conflict on the other. Current fault-tolerant technologies for steer-by-wire only focus on compensating for steering function and rely on accurate estimation of faults, while lacking attention to target conflicts.

[0065] The fault-tolerant control method for human-machine co-driving steer-by-wire systems is applied to the fault-tolerant control device of human-machine co-driving steer-by-wire systems. Figure 1 This paper presents a schematic diagram of the overall flow of a fault-tolerant control method for a human-machine co-driving steer-by-wire system. Figure 1 , Figure 2 This paper presents a schematic diagram of the overall flow of a fault-tolerant control method for a human-machine co-driving steer-by-wire system. Figure 2 .like Figure 1 and Figure 2 As shown, it includes:

[0066] S1. Construct a driver-vehicle coupling model.

[0067] The driver-vehicle coupling model considers unknown bounded disturbances caused by steering system failures. This model includes a system state vector, a control input vector, and a fault disturbance vector. The fault disturbance vector is used to simulate various fault scenarios in the steer-by-wire system. The expression for the driver-vehicle coupling model is shown below:

[0068] x(k+1)=Ax(k)+B1u (1) (k)+B2u (2) (k)+B d d+w(k) (1)

[0069] Where x(k+1) is the driver-vehicle system state vector at the next moment, x(k) is the driver-vehicle system state vector, including vehicle dynamics, kinematic state, steering system angle state, and driver behavior state, A is the state matrix, used to describe the internal dynamic characteristics of the driver-vehicle system, B1 is the first participant input matrix, B2 is the second participant input matrix, used to describe the effect of participant input on the system state, u (1) (k) represents the control input of the first participant to the driver-vehicle system, u (1) (k)=[τ m M zf ] T , τ m M is the torque of the steering motor. zf For the front axle differential torque, u (2) (k) represents the control input of the second participant to the driver-vehicle system, u (2) (k)=[τ m M zf M zr ] T M zr For the rear axle differential torque, B d d represents the self-centering torque and friction torque of the steering system, and w(k) represents the bounded disturbance caused by steering motor failure and unmodeled dynamics.

[0070] Furthermore, the fault disturbance vector is calculated using a fault model, the expression of which is shown below:

[0071] τ s =ετ m +Δτ m (2),

[0072] Where, τ s τ is the actual output torque of the motor, ε is the fault factor, and τ is the actual output torque of the motor. m For the steering motor torque, Δτ m This refers to the offset torque caused by the fault.

[0073] S2. Construct an outer-loop non-cooperative game model, setting the driver as the first participant and the intelligent driving system as the second participant. Assign differentiated control objectives to the first participant and the second participant respectively, and define the control input and cost functions for both parties.

[0074] In this process, an outer-loop non-cooperative game model based on distributed model predictive control is established based on the driver-vehicle coupling model established in step S1. The first participant pursues a trajectory tracking objective, mathematically expressed as the output matrix of the state-space equation of the driver-vehicle coupling model. The control inputs are the steering motor torque and the front axle differential torque. The second participant pursues a stability control objective, similarly expressed as the output matrix of the state-space equation of the driver-vehicle coupling model. The control inputs are the steering motor torque, the front axle differential torque, and the rear axle differential torque. The expression for the inner and outer loop hybrid game framework is shown below:

[0075]

[0076] stx(k+1)=Ax(k)+B1u (1) (k)+B2u (2) (k)+B d d+w(k)

[0077] y (i) (k)=C (i) x(k)

[0078]

[0079] i = 1, 2

[0080] Where i = 1, 2 represent the first participant and the second participant, respectively; u (i) (k) is the control input; Δy (i) (k) represents the system output error, which is the sum of the expected vector and the system output vector y. (i) The difference of (k); Q (i) The system output error weight matrix is ​​a diagonal matrix; R (i) The control input weight matrix is ​​a diagonal matrix; C (i) For the output matrix, different C (i) The different system output vectors y are determined (i) (k), for example, the system state vector is:

[0081]

[0082] when At that time, y (1) (k)=[Y(k) δ f (k)] T This indicates that the system output represents the trajectory tracking performance that the driver is concerned about. At that time, y (2) (k)=[β(k) ω(k)] TThis indicates that the system output represents the stability control performance that the intelligent driving system is concerned with; and These are the upper and lower limits of the system control input, respectively.

[0083] S3. Embed an inner-loop chase-escape game into the outer-loop non-cooperative game model. Model the control target performance of the first participant as the first pursuer and the corresponding fault disturbance as the first escapee. Model the control target performance of the second participant as the second pursuer and the corresponding fault disturbance as the second escapee, thus obtaining a hybrid inner-loop game framework.

[0084] The expression for the inner-loop pursuit game is as follows:

[0085]

[0086] stx(k+1)=Ax(k)+B1u (1) (k)+B2u (2) (k)+B d d+w (i) (k)

[0087] y (i) (k)=C (i) x(k)

[0088]

[0089] i = 1, 2

[0090] in, Let be the cost function of the participants in the pursuit-escape game; and Let w be the lower and upper bounds of the system perturbation; the inner-loop chase game framework represents the system perturbation w. (i) (k) The goal is to maximize the cost function, but the control input u (i) (k) Minimize the expected cost function. According to the definition of the saddle point in the pursuit-escape game, the optimization problems of the pursuer and the escapee can be expressed separately.

[0091] Furthermore, the optimization problem for the first and second pursuers is expressed as follows:

[0092]

[0093] stx(k+1)=Ax(k)+B1u (1) (k)+B2u (2) (k)+B d d+w (i) (k)

[0094] y (i) (k)=C(i) x(k)

[0095]

[0096] in, For the cost function of the pursuer in a pursuit game, w (i)* (k) represents the optimal solution for the escapee.

[0097] Furthermore, the optimization problem for the first and second escapees is expressed as follows:

[0098]

[0099] stx(k+1)=Ax(k)+B1u (1) (k)+B2u (2) (k)+B d d+w (i) (k)

[0100] y (i) (k)=C (i) x(k)

[0101]

[0102] in, Let u be the cost function of the escapee in the pursuit game. (i)* (k) is the optimal solution for the pursuer.

[0103] S4. Solve for the equilibrium solution of the inner and outer loop hybrid game framework to obtain the optimal control input of the first and second participants, and realize the fault-tolerant control of the steer-by-wire system.

[0104] From equation (4), it can be seen that the optimal solution u for the first participant is obtained. (1)* (k) depends on the optimal solution w of equation (5) (1)* (k) and the optimal solution u of the second participant (2)* Similarly, it can be seen that the optimal solution u for the second participant is (k). (2)* (k) depends on the optimal solution w of equation (5) (2)* (k) and the optimal solution u of the first participant (1)* (k), therefore the solutions to the inner and outer loop games are coupled and difficult to solve directly.

[0105] Specifically, step S4 includes the following sub-steps:

[0106] S401, Perform initialization processing.

[0107] Specifically, when k = 0, let u (1)* (0)=0 and u (2)*(0) = 0, w (1)* (0) = 0 and w (2)* (0) = 0.

[0108] S402, the optimal control input of the first participant and the optimal control input of the second participant in the previous time step.

[0109] Specifically, when k>0, the input is the optimal solution u of the first and second participants at the previous time step. (1)* (k-1) and u (2)* (k-1).

[0110] S403. Based on the initialization results, solve the saddle point solution of the inner loop chase-escape game to obtain the optimal fault disturbance strategy for the first and second escapees.

[0111] Specifically, based on u (1)* (k-1) and u (2)* (k-1) Solve the solution w of equation (5) in the inner loop game. (1)* (k) and w (2)* (k).

[0112] S404. Substitute the optimal fault disturbance strategy into the outer-loop non-cooperative game model to solve for the optimal control inputs of the first and second participants.

[0113] Specifically, w (1)* (k) and w (2)* (k) is passed to equation (4) to solve for the solution u of the first and second players in the mixed game. (1)* (k) and u (2)* (k), and the optimal solution u of the first participant. (1)* (k) is passed to the second participant, and the second participant's optimal solution u is also passed to the second participant. (2)* (k) is passed to the first participant.

[0114] S405. Repeat the process of substituting the optimal control input of the first participant and the optimal control input of the second participant from the previous time step into the outer-loop non-cooperative game model to solve for the optimal control input of the first participant and the second participant, until the difference between the optimal control inputs of two adjacent iterations is less than a preset threshold, and output the final equilibrium solution.

[0115] This example provides a fault-tolerant control method for a human-machine co-driving steer-by-wire system. First, a driver-vehicle coupled model is constructed, followed by an outer-loop non-cooperative game model. Then, an inner-loop pursuit-escape game is embedded within this outer-loop model. Finally, the equilibrium solution of this hybrid game framework is solved to obtain the optimal control input for both participants, achieving fault-tolerant control of the steer-by-wire system. By using a hybrid game framework that coordinates human-machine objectives in the outer loop and handles fault disturbances in the inner loop, this method effectively resolves the differences in control objectives and potential command conflicts between the driver and the intelligent driving system in human-machine co-driving scenarios, overcoming the limitations of fault compensation and light-objective coordination in existing technologies. Furthermore, it can cope with steering system faults, achieving fault-tolerant control without relying on precise fault information. Ultimately, while considering the needs of different control subjects, it ensures the stability and reliability of vehicle operation, meeting the high precision and high safety requirements for steering control in human-machine co-driving scenarios.

[0116] For those consistent with the above, please refer to Figure 3 , Figure 3 This application provides a schematic diagram of the fault-tolerant control device for a human-machine co-driving steer-by-wire system. (See attached diagram.) Figure 3 As shown, the device includes:

[0117] The first processing unit 1 is used to construct a driver-vehicle coupling model;

[0118] The second processing unit 2 is used to construct an outer-loop non-cooperative game model, setting the driver as the first participant and the intelligent driving system as the second participant, assigning differentiated control objectives to the first participant and the second participant respectively, and defining the control input and cost functions for both parties;

[0119] The third processing unit 3 is used to embed an inner-loop chase-escape game into the outer-loop non-cooperative game model, modeling the control target performance of the first participant as the first pursuer and the corresponding fault disturbance as the first escapee; modeling the control target performance of the second participant as the second pursuer and the corresponding fault disturbance as the second escapee, thus obtaining an inner-loop hybrid game framework.

[0120] Control unit 4 is used to solve the equilibrium solution of the inner and outer loop hybrid game framework, obtain the optimal control input of the first and second participants, and realize the fault-tolerant control of the steer-by-wire system.

[0121] For examples consistent with the above embodiments, please refer to... Figure 4 , Figure 4A schematic diagram of a terminal structure provided in an embodiment of this application is shown in the figure. It includes a processor, an input device, an output device, and a memory. The processor, input device, output device, and memory are interconnected. The memory is used to store a computer program, which includes program instructions. The processor is configured to call the program instructions. The program includes instructions for performing the following steps.

[0122] Construct a driver-vehicle coupling model;

[0123] A non-cooperative game model for the outer loop is constructed, with the driver as the first participant and the intelligent driving system as the second participant. Differentiated control objectives are assigned to the first participant and the second participant respectively, and the control inputs and cost functions of both parties are defined.

[0124] An inner-loop chase-escape game is embedded in the outer-loop non-cooperative game model. The control target performance of the first participant is modeled as the first pursuer, and the corresponding fault disturbance is modeled as the first escapee. The control target performance of the second participant is modeled as the second pursuer, and the corresponding fault disturbance is modeled as the second escapee, thus obtaining a hybrid inner-loop game framework.

[0125] Solving the equilibrium solution of the inner and outer loop hybrid game framework yields the optimal control inputs for the first and second participants, enabling fault-tolerant control of the steer-by-wire system.

[0126] This example provides a fault-tolerant control method for a human-machine co-driving steer-by-wire system. First, a driver-vehicle coupled model is constructed, followed by an outer-loop non-cooperative game model. Then, an inner-loop pursuit-escape game is embedded within this outer-loop model. Finally, the equilibrium solution of this hybrid game framework is solved to obtain the optimal control input for both participants, achieving fault-tolerant control of the steer-by-wire system. By using a hybrid game framework that coordinates human-machine objectives in the outer loop and handles fault disturbances in the inner loop, this method effectively resolves the differences in control objectives and potential command conflicts between the driver and the intelligent driving system in human-machine co-driving scenarios, overcoming the limitations of fault compensation and light-objective coordination in existing technologies. Furthermore, it can cope with steering system faults, achieving fault-tolerant control without relying on precise fault information. Ultimately, while considering the needs of different control subjects, it ensures the stability and reliability of vehicle operation, meeting the high precision and high safety requirements for steering control in human-machine co-driving scenarios.

[0127] The above mainly describes the solutions of the embodiments of this application from the perspective of the method execution process. It is understood that, in order to achieve the above functions, the terminal includes the corresponding hardware structure and / or software modules for executing each function. Those skilled in the art should readily recognize that, in conjunction with the units and algorithm steps of the various examples described in the embodiments provided herein, this application can be implemented in hardware or a combination of hardware and computer software. Whether a function is executed in hardware or by computer software driving hardware depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0128] This application embodiment can divide the terminal into functional units according to the above method example. For example, each function can be divided into a separate functional unit, or two or more functions can be integrated into one processing unit. The integrated unit can be implemented in hardware or as a software functional unit. It should be noted that the unit division in this application embodiment is illustrative and only represents one logical functional division. In actual implementation, there may be other division methods.

[0129] This application also provides a computer storage medium storing a computer program for electronic data exchange, which causes a computer to perform some or all of the steps of any of the fault-tolerant control methods for human-machine co-driving steer-by-wire systems described in the above method embodiments.

[0130] This application also provides a computer program product, which includes a non-transitory computer-readable storage medium storing a computer program that causes a computer to perform some or all of the steps of any of the fault-tolerant control methods for human-machine co-driving steer-by-wire systems described in the above method embodiments.

[0131] It should be noted that, for the sake of simplicity, the foregoing method embodiments are all described as a series of actions. However, those skilled in the art should understand that this application is not limited to the described order of actions, as some steps may be performed in other orders or simultaneously according to this application. Furthermore, those skilled in the art should also understand that the embodiments described in the specification are preferred embodiments, and the actions and modules involved are not necessarily essential to this application.

[0132] In the above embodiments, the descriptions of each embodiment have different focuses. For parts not described in detail in a certain embodiment, please refer to the relevant descriptions in other embodiments.

[0133] In the several embodiments provided in this application, it should be understood that the disclosed apparatus can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative; for instance, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be through some interfaces; the indirect coupling or communication connection between devices or units may be electrical or other forms.

[0134] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0135] Furthermore, the functional units in the various embodiments of the application can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software program module.

[0136] If the integrated unit is implemented as a software program module and sold or used as an independent product, it can be stored in a computer-readable storage device (CMD). Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, or all or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a memory and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of this application. The aforementioned memory includes various media capable of storing program code, such as USB flash drives, read-only memory (ROM), random access memory (RAM), portable hard drives, magnetic disks, or optical disks.

[0137] Those skilled in the art will understand that all or part of the steps in the various methods of the above embodiments can be implemented by a program instructing related hardware. The program can be stored in a computer-readable storage device, which may include: a flash drive, a read-only memory, a random access memory, a magnetic disk, or an optical disk, etc.

[0138] The embodiments of this application have been described in detail above. Specific examples have been used to illustrate the principles and implementation methods of this application. The description of the above embodiments is only for the purpose of helping to understand the method and core ideas of this application. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the ideas of this application. Therefore, the content of this specification should not be construed as a limitation of this application.

Claims

1. A fault-tolerant control method for a human-machine co-driving steer-by-wire system, characterized in that, include: Construct a driver-vehicle coupling model; A non-cooperative game model for the outer loop is constructed, with the driver as the first participant and the intelligent driving system as the second participant. Differentiated control objectives are assigned to the first participant and the second participant respectively, and the control inputs and cost functions of both parties are defined. An inner-loop pursuit-escape game is embedded in the outer-loop non-cooperative game model, and the control target performance of the first participant is modeled as the first pursuer, while the corresponding fault disturbance is modeled as the first escapee. The control objective performance of the second participant is modeled as the second pursuer, and the corresponding fault disturbance is modeled as the second escapee, thus obtaining the inner and outer loop hybrid game framework; Solving for the equilibrium solution of the inner and outer loop hybrid game framework yields the optimal control inputs for the first and second participants, enabling fault-tolerant control of the steer-by-wire system.

2. The fault-tolerant control method for the human-machine co-driving steer-by-wire system according to claim 1, characterized in that, The driver-vehicle coupling model includes a system state vector, a control input vector, and a fault disturbance vector. The fault disturbance vector is used to simulate various fault scenarios of the steer-by-wire system. The expression of the driver-vehicle coupling model is as follows: x(k+1)=Ax(k)+B1u (1) (k)+B2u (2) (k)+B d d+w(k) Where x(k+1) is the driver-vehicle system state vector at the next time step, x(k) is the driver-vehicle system state vector, A is the state matrix, B1 is the input matrix of the first participant, B2 is the input matrix of the second participant, and u (1) (k) represents the control input of the first participant to the driver-vehicle system, u (2) (k) represents the control input of the second participant to the driver-vehicle system, B d d represents the self-centering torque and friction torque of the steering system, and w(k) represents the bounded disturbance caused by steering motor failure and unmodeled dynamics.

3. The fault-tolerant control method for the human-machine co-driving steer-by-wire system according to claim 2, characterized in that, The fault disturbance vector is calculated using a fault model, the expression of which is shown below: t s =year m +Δt m , Where, τ s τ is the actual output torque of the motor, ε is the fault factor, and τ is the actual output torque of the motor. m For the steering motor torque, Δτ m This refers to the offset torque caused by the fault.

4. The fault-tolerant control method for the human-machine co-driving steer-by-wire system according to claim 1, characterized in that, The outer-loop non-cooperative game model is constructed, with the driver as the first participant and the intelligent driving system as the second participant. Differentiated control objectives are assigned to the first and second participants respectively, and the control inputs and cost functions for both parties are defined. The expression of the inner-outer-loop hybrid game framework is as follows: Where, Δy (i) (k) represents the system output error, u (i) (k) is the control input, Q (i) R is the system output error weight matrix. (i) To control the input weight matrix, C (i) For the output matrix, and These are the lower and upper limits for system control inputs.

5. The fault-tolerant control method for the human-machine co-driving steer-by-wire system according to claim 1, characterized in that, The inner-loop pursuit and escape game is embedded in the outer-loop non-cooperative game model, and the control target performance of the first participant is modeled as the first pursuer, and the corresponding fault disturbance is modeled as the first escapee. By modeling the control objective performance of the second participant as the second pursuer and the corresponding fault disturbance as the second escapee, the expression of the inner-loop pursuit-escape game in the inner-outer-loop hybrid game framework is obtained as follows: in, Let w be the cost function of the participants in the pursuit game. (i) (k) represents the system disturbance. and These represent the lower and upper limits of the system disturbance.

6. The fault-tolerant control method for the human-machine co-driving steer-by-wire system according to claim 1, characterized in that, The inner-loop pursuit and escape game is embedded in the outer-loop non-cooperative game model, and the control target performance of the first participant is modeled as the first pursuer, and the corresponding fault disturbance is modeled as the first escapee. By modeling the control objective performance of the second participant as the second pursuer and the corresponding fault disturbance as the second escapee, the expression for the optimization problem of the first pursuer and the second pursuer in the inner and outer loop hybrid game framework is obtained as follows: in, For the cost function of the pursuer in a pursuit game, w (i)* (k) represents the optimal solution for the escapee.

7. The fault-tolerant control method for the human-machine co-driving steer-by-wire system according to claim 1, characterized in that, The inner-loop pursuit and escape game is embedded in the outer-loop non-cooperative game model, and the control target performance of the first participant is modeled as the first pursuer, and the corresponding fault disturbance is modeled as the first escapee. By modeling the control objective performance of the second participant as the second pursuer and the corresponding fault disturbance as the second escapee, the optimization problem for the first and second escapees in the inner and outer loop hybrid game framework is expressed as follows: in, Let u be the cost function of the escapee in the pursuit game. (i)* (k) is the optimal solution for the pursuer.

8. The fault-tolerant control method for the human-machine co-driving steer-by-wire system according to claim 1, characterized in that, Solving for the equilibrium solution of the inner and outer loop hybrid game framework includes: Perform initialization processing; The optimal control input of the first participant and the optimal control input of the second participant at the previous time step; Based on the initialization results, the saddle point solution of the inner loop chase-escape game is solved to obtain the optimal fault disturbance strategy of the first and second escapees. Substitute the optimal fault disturbance strategy into the outer-loop non-cooperative game model to solve for the optimal control inputs of the first and second participants. Repeat the initialization of the optimal control inputs of the first and second participants from the previous time step until the optimal fault disturbance strategy is substituted into the outer-loop non-cooperative game model. Solve for the optimal control inputs of the first and second participants until the difference between the optimal control inputs of two adjacent iterations is less than a preset threshold, and output the final equilibrium solution.

9. A fault-tolerant control device for a human-machine co-driving steer-by-wire system, characterized in that, include: The first processing unit is used to construct the driver-vehicle coupling model; The second processing unit is used to construct an outer-loop non-cooperative game model, setting the driver as the first participant and the intelligent driving system as the second participant, assigning differentiated control objectives to the first participant and the second participant respectively, and defining the control inputs and cost functions for both parties. The third processing unit is used to embed an inner-loop pursuit and escape game into the outer-loop non-cooperative game model, modeling the control target performance of the first participant as the first pursuer and the corresponding fault disturbance as the first escapee. The control objective performance of the second participant is modeled as the second pursuer, and the corresponding fault disturbance is modeled as the second escapee, thus obtaining the inner and outer loop hybrid game framework; The control unit is used to solve the equilibrium solution of the inner and outer loop hybrid game framework, obtain the optimal control input of the first and second participants, and realize the fault-tolerant control of the steer-by-wire system.

10. A terminal, characterized in that, The system includes a processor, an input device, an output device, and a memory, which are interconnected. The memory stores a computer program, which includes program instructions. The processor is configured to invoke the program instructions to execute the fault-tolerant control method for a human-machine co-driving steer-by-wire system as described in any one of claims 1-8.

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