Modeling methods, devices and electronic equipment for rear wheel steering systems

Abstract

This invention proposes a modeling method, device, and electronic device for a rear-wheel steering system, relating to the field of vehicle technology. It is used to model and simulate the rear-wheel steering system of a vehicle, comprising: constructing a dynamic model of the rear-wheel steering system by adding a steering rack module and a steering tie rod inner bushing module to the rear suspension subsystem template in Adams; wherein the steering rack module and the steering tie rod inner bushing module are connected; the steering rack module is used to drive the rear wheels for steering; constructing a control algorithm model of the rear-wheel steering system using Simulink, and encapsulating the control algorithm model into a functional model unit (FMU); creating sensors and actuators that match the signals of the functional model unit in the vehicle subsystem template in Adams; associating the FMU with the dynamic model, sensors, and actuators to obtain the model of the rear-wheel steering system, wherein the sensors are connected to the input terminals of the FMU, and the actuators are connected to the output terminals of the FMU.

Description

Technical Field

[0001] This invention relates to the field of vehicle technology, and more specifically to a modeling method, apparatus, and electronic device for a rear-wheel steering system. Background Technology

[0002] Rear-wheel steering (RWS) technology has gradually become a development direction for improving vehicle performance due to its ability to improve vehicle following, suppress body roll, and enhance high-speed stability, thus compensating for the shortcomings of front-wheel steering. However, in the actual development process of rear-wheel steering systems, the research and iteration of rear-wheel steering technology requires real-vehicle testing to correct system structural parameters or optimize control algorithms. Each parameter adjustment necessitates repeating real-vehicle testing, which severely impacts the development efficiency of rear-wheel steering technology.

[0003] Simulation technology, as a low-cost and high-efficiency virtual development method, can optimize the structure and control algorithm of the rear-wheel steering system through virtual modeling and simulation verification. It eliminates the need for repeated real-vehicle tests, which can significantly shorten the development cycle and reduce R&D costs, and can precisely solve the problems in the development of the rear-wheel steering system.

[0004] Therefore, there is an urgent need for a modeling method for rear-wheel steering systems to support their development. Summary of the Invention

[0005] One of the objectives of this invention is to provide a modeling method, device, and electronic device for a rear-wheel steering system, so as to realize the modeling and simulation of the rear-wheel steering system of a vehicle.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows: In a first aspect, the present invention provides a modeling method for a rear-wheel steering system, comprising: constructing a dynamic model of the rear-wheel steering system by adding a steering rack module and a steering tie rod inner point bushing module to the rear suspension subsystem template of a vehicle model in Adams; wherein the steering rack module and the steering tie rod inner point bushing module are connected; the steering rack module is used to drive the rear wheels of the vehicle model to steer; constructing a control algorithm model of the rear-wheel steering system using Simulink, and encapsulating the control algorithm model into a functional model unit (FMU); creating sensors and actuators that match the signals of the functional model unit in the vehicle subsystem template of Adams; the sensors are used to collect physical signals of the dynamic model; the actuators are used to output signals that drive the steering rack module to move; associating the FMU with the dynamic model, sensors, and actuators to obtain a model of the rear-wheel steering system, wherein the sensors are connected to the input end of the FMU, and the actuators are connected to the output end of the FMU.

[0007] Based on the aforementioned technical means, a dynamic model of the rear-wheel steering system is constructed by adding a steering rack module and a steering tie rod inner bushing module to the rear suspension subsystem template in Adams. Then, an FMU unit corresponding to the control algorithm model of the rear-wheel steering system, along with sensors and actuators, is constructed. The input of the FMU unit corresponds to the output of the sensor, and the output of the FMU unit corresponds to the input of the actuator. During model operation, the FMU outputs control drive signals to the actuator, which converts the control drive signals and applies them to the steering rack module of the dynamic model. The sensors collect the physical signals of the dynamic model and feed them back to the input of the FMU, thereby realizing a signal closed loop between the dynamic model and the control algorithm model, constructing a simulation model that integrates mechanics and control, and thus providing a model foundation for the simulation verification of the rear-wheel steering system.

[0008] Furthermore, the dynamic model includes: a steering gear housing module and a steering tie rod module; the inner side of the steering gear rack module is connected to the steering gear housing module; the outer side of the steering gear rack module is connected to the steering tie rod module through the steering tie rod inner bushing module.

[0009] Based on the above technical means, by using the steering rack module with the inner side connected to the housing and the outer side connected to the steering tie rod module via the bushing module, the mechanical structure of the actual rear wheel steering system is accurately replicated. At the same time, the steering housing module and the steering tie rod module directly reuse the original components of the Adams rear suspension subsystem template, which not only greatly reduces the workload of component building and constraint configuration during modeling, but also ensures the structural compatibility between the dynamic model and the original rear suspension template.

[0010] Furthermore, the dynamic model includes a rear-wheel steering control component, which is used to control the activation or deactivation of the rear-wheel steering function.

[0011] Based on the above technical means, by setting up a rear wheel steering control component, the rapid opening and closing control of the rear wheel steering function can be achieved without reconstructing the dynamic model or adjusting the connection relationship of each module.

[0012] Furthermore, when the rear wheel steering control assembly is activated, the inner point of the steering tie rod module is connected to the outer side of the steering rack module through the steering tie rod inner point bushing module; or, when the rear wheel steering control assembly is deactivated, the inner point of the steering tie rod module is connected to the steering housing module.

[0013] Based on the above technical means, the connection relationship of each component module of the rear wheel steering system is adjusted by the rear wheel steering control component. The basic components and constraint relationship of the original rear suspension model are not changed during the control process. The function is switched only by switching the connection relationship of each module, which improves the ease of operation and ensures the compatibility of the model with Adams' original system template.

[0014] Furthermore, the above method also includes: importing the vehicle's motion parameters under different operating conditions into the model of the rear-wheel steering system, and applying driving force to the steering rack module; the operating conditions include at least one of the following: U-turn condition and double lane change condition; comparing the steering parameters of the rear-wheel steering control component in the on and off states to obtain the test results of the rear-wheel steering system; the steering parameters include at least one of the following: turning radius and yaw rate; the test results are used to characterize the improvement effect of the rear-wheel steering system on the vehicle's steering performance.

[0015] Based on the above technical means, the motion parameters of the vehicle under different working conditions are imported into the model of the rear wheel steering system, and a driving force is applied to the steering rack. The steering parameters of the rear wheel steering control component in the open and closed states are compared to obtain the test results of the rear wheel steering system. The performance of the rear wheel steering system can be verified under multiple working conditions in a virtual simulation environment.

[0016] Furthermore, applying a driving force to the steering rack module includes: applying a driving force to the steering rack module based on a preset functional relationship; and / or, applying a driving force to the steering rack module based on a signal output by the FMU.

[0017] Based on the aforementioned technical means, by applying driving force to the steering rack through a preset functional relationship and / or the signal output by the FMU, the driving force can be flexibly applied under different simulation verification targets, adapting to different simulation requirements. Applying driving force based on the preset functional relationship allows for independent driving of the rack movement, detached from the control algorithm, enabling rapid verification of the kinematic characteristics of mechanical components such as the steering rack and tie rod. Applying driving force based on the FMU output signal can reproduce the control logic of the control algorithm and mechanical structure in an actual vehicle, accurately verifying the matching degree between the control algorithm output and the mechanical system.

[0018] Furthermore, the physical signals include at least one of the following: vehicle speed, yaw rate, center of gravity sideslip angle, front wheel angle, and steering wheel angle; the sensors are respectively arranged in the body subsystem template, front suspension subsystem template, and steering subsystem template of the Adams vehicle subsystem template.

[0019] Based on the above technical means, the sensor layout method based on the native subsystem template does not require modification of Adams' original architecture, thus ensuring model compatibility.

[0020] Secondly, the present invention provides a modeling device for a rear-wheel steering system, comprising: a first building unit for constructing a dynamic model of the rear-wheel steering system by adding a steering rack module and a steering tie rod inner point bushing module to the rear suspension subsystem template of a vehicle model in Adams; wherein the steering rack module and the steering tie rod inner point bushing module are connected; the steering rack module is used to drive the rear wheels of the vehicle model to steer; a second building unit for constructing a control algorithm model of the rear-wheel steering system through Simulink, and encapsulating the control algorithm model into a functional model unit (FMU); a third building unit for creating sensors and actuators matched with the FMU in the vehicle subsystem template of Adams; the sensors are used to collect physical signals from the dynamic model; the actuators are used to output signals that drive the steering rack module to move; and a processing unit for associating the FMU with the dynamic model, sensors, and actuators to obtain a model of the rear-wheel steering system, wherein the sensors are connected to the input end of the FMU, and the actuators are connected to the output end of the FMU.

[0021] Thirdly, the present invention provides an electronic device comprising: a processor and a memory; the memory for storing processor-executable instructions; wherein the processor is configured to execute the instructions to implement the methods of the first aspect described above and any possible implementation thereof.

[0022] Fourthly, the present invention provides a computer-readable storage medium that, when the instructions in the computer-readable storage medium are executed by a processor of an electronic device, enables the electronic device to perform the methods described in the first aspect and any possible embodiments thereof.

[0023] Fifthly, the present invention provides a computer program product comprising computer instructions that, when executed on an electronic device, cause the electronic device to perform the method described in the first aspect and any possible implementation thereof.

[0024] The beneficial effects of this invention are: (1) By adding a steering rack module and a steering tie rod inner bushing module to the rear suspension subsystem template in Adams, a dynamic model of the rear wheel steering system is constructed. Then, the FMU unit corresponding to the control algorithm model of the rear wheel steering system, as well as sensors and actuators, are constructed. The input of the FMU unit corresponds to the output of the sensor, and the output of the FMU unit corresponds to the input of the actuator. When the model is running, the FMU outputs control drive signals to the actuator, the actuator converts the control drive signals and applies them to the steering rack module of the dynamic model, and the sensor collects the physical signals of the dynamic model and feeds them back to the input of the FMU, thereby realizing the signal closed loop between the dynamic model and the control algorithm model, constructing a simulation model integrating mechanics and control, which can provide a model basis for the simulation verification of the rear wheel steering system.

[0025] (2) By using the steering rack module to connect the inner side to the housing and the outer side to the steering tie rod module via the bushing module, the mechanical structure of the actual rear wheel steering system is accurately replicated. At the same time, the steering housing module and the steering tie rod module directly reuse the original components of the Adams rear suspension subsystem template, which not only greatly reduces the workload of component building and constraint configuration during modeling, but also ensures the structural compatibility between the dynamic model and the original rear suspension template.

[0026] (3) By setting up a rear wheel steering control component, the rear wheel steering function can be quickly opened and closed without reconstructing the dynamic model or adjusting the connection relationship of each module.

[0027] (4) The connection relationship of each component module of the rear wheel steering system is adjusted by the rear wheel steering control component. The basic components and constraint relationship of the original rear suspension model are not changed during the control process. The function is switched only by switching the connection relationship of each module, which improves the ease of operation and ensures the compatibility of the model with Adams' original system template.

[0028] (5) Import the motion parameters of the vehicle under different working conditions into the model of the rear wheel steering system, apply driving force to the steering rack, compare the steering parameters of the rear wheel steering control component in the open and closed states, and obtain the test results of the rear wheel steering system. The performance of the rear wheel steering system can be verified under multiple working conditions in a virtual simulation environment.

[0029] (6) By applying driving force to the steering rack through a preset functional relationship and / or the signal output by the FMU, the driving force can be flexibly applied under different simulation verification targets to adapt to different simulation requirements. Applying driving force based on the preset functional relationship can drive the rack independently of the control algorithm, and quickly verify the kinematic characteristics of mechanical components such as the steering rack and steering tie rod. Applying driving force based on the FMU output signal can restore the control logic of the control algorithm and mechanical structure in the actual vehicle, and accurately verify the matching degree between the control algorithm output and the mechanical system.

[0030] (7) The sensor layout method based on the native subsystem template does not require any changes to Adams’ original architecture, thus ensuring model compatibility. Attached Figure Description

[0031] Figure 1 This is a flowchart illustrating a modeling method for a rear-wheel steering system proposed in this invention. Figure 2 This is a flowchart illustrating another modeling method for a rear-wheel steering system proposed in this invention. Figure 3 This is a schematic diagram of a rear-wheel steering system proposed in this invention; Figure 4 This is a schematic diagram of a process for packaging an FMU unit according to the present invention; Figure 5 This is a schematic diagram of a process for creating a control algorithm model according to the present invention; Figure 6 This is a schematic diagram illustrating the interaction between a dynamic model and a control algorithm model proposed in this invention. Figure 7 This is a schematic diagram illustrating the change in yaw rate when the rear wheel steering function is activated and deactivated under dual lane change conditions, as proposed in this invention. Figure 8 This is a schematic diagram of the structure of a modeling device for a rear wheel steering system proposed in this invention; Figure 9 This is a schematic diagram of the structure of an electronic device proposed in this invention. Detailed Implementation

[0032] The embodiments of the present invention will be described below with reference to the accompanying drawings and preferred embodiments. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention. It should be understood that the preferred embodiments are only for illustrating the present invention and not for limiting the scope of protection of the present invention.

[0033] It should be noted that the illustrations provided in the following embodiments are only schematic representations of the basic concept of the present invention. Therefore, the drawings only show the components related to the present invention and are not drawn according to the actual number, shape and size of the components in the actual implementation. In the actual implementation, the form, quantity and proportion of each component can be arbitrarily changed, and the layout of the components may also be more complex.

[0034] Currently, front-wheel steering is the mainstream steering method for vehicles. Front-wheel steering uses mechanical structures such as a steering wheel, steering gear, and steering tie rods to control the front wheels to deflect at a certain angle, thereby turning the vehicle. While this steering mode can meet the basic driving needs of a vehicle, it has significant limitations in actual use: at low speeds, because it relies solely on the deflection of the front wheels, the turning radius of the vehicle is relatively large, resulting in insufficient maneuverability and making it difficult to adapt to confined spaces; at high speeds (such as high-speed cornering or emergency lane changes), the vehicle's responsiveness is poor, and phenomena such as center of gravity shift and vehicle fishtailing are prone to occur, resulting in insufficient handling stability.

[0035] Rear-wheel steering is a technology that uses a specific actuator to drive the rear wheels to deflect at a certain angle, coordinating with the front wheels to complete the vehicle's steering action. Its principle is to dynamically adjust the direction and angle of rear wheel deflection based on operating parameters such as vehicle speed and steering angle: at low speeds, the rear wheels deflect in the opposite direction to the front wheels, significantly reducing the vehicle's turning radius and improving low-speed handling agility; at high speeds, the rear wheels deflect in the same direction as the front wheels, improving vehicle responsiveness, suppressing body roll, and enhancing high-speed stability, thus effectively compensating for the shortcomings of traditional front-wheel steering. Therefore, rear-wheel steering technology is gradually becoming a development direction for improving vehicle performance.

[0036] However, in the actual development process of rear-wheel steering systems, the research and development iteration of rear-wheel steering technology requires real vehicle testing to correct system structural parameters or optimize control algorithms. Moreover, each parameter adjustment requires a new real vehicle test, which seriously affects the development efficiency of rear-wheel steering technology.

[0037] Simulation technology, as a low-cost and high-efficiency virtual development method, can optimize the structure and control algorithm of the rear-wheel steering system through virtual modeling and simulation verification. This eliminates the need for repeated real-vehicle testing, significantly shortening the development cycle and reducing R&D costs, and effectively addressing the problems encountered in rear-wheel steering system development. Currently, there is an urgent need for a modeling methodology for rear-wheel steering systems to support their development.

[0038] Based on this, this application provides a modeling method for a rear-wheel steering system. A dynamic model of the rear-wheel steering system is constructed by adding a steering rack module and a steering tie rod inner bushing module to the rear suspension subsystem template in Adams. Then, an FMU unit corresponding to the control algorithm model of the rear-wheel steering system, along with sensors and actuators, are constructed. The input of the FMU unit corresponds to the output of the sensors, and the output of the FMU unit corresponds to the input of the actuators. During model operation, the FMU outputs control drive signals to the actuators, which convert and apply these signals to the steering rack module of the dynamic model. The sensors collect the physical signals of the dynamic model and feed them back to the input of the FMU, thus achieving a signal closed loop between the dynamic model and the control algorithm model. This constructs a mechatronics simulation model of the rear-wheel steering system, providing a model foundation for the simulation verification of the rear-wheel steering system.

[0039] In some embodiments, the executing entity of the rear-wheel steering system modeling method of this application may be a rear-wheel steering system modeling device, which may be an electronic device. Optionally, the rear-wheel steering system modeling device may also be a functional module of the aforementioned electronic device used to execute the rear-wheel steering system modeling method. This embodiment of the invention does not impose any limitations on this.

[0040] like Figure 1 As shown, this application provides a modeling method for a rear-wheel steering system, including the following steps: S101. By adding the steering rack module and the steering tie rod inner point bushing module to the rear suspension subsystem template of the vehicle model in Adams, a dynamic model of the rear wheel steering system is constructed.

[0041] The steering rack module is connected to the steering tie rod inner bushing module; the steering rack module is used to drive the rear wheels of the vehicle model for steering.

[0042] Adams can simulate the motion, forces, and constraints of mechanical structures. It is a tool for simulating mechanical systems and can accurately reproduce the actual motion characteristics of physical components.

[0043] The rear suspension subsystem template is a preset mechanical model template of the vehicle rear suspension without rear wheel steering function in Adams. It includes native rear suspension components such as subframe, steering tie rod, and control arm, as well as constraint relationships. It is the basis for the dynamic model used to construct the rear wheel steering system in this application.

[0044] In one implementation, the dynamic model includes: a steering gear housing module and a steering tie rod module; the inner side of the steering gear rack module is connected to the steering gear housing module; the outer side of the steering gear rack module is connected to the steering tie rod module through the steering tie rod inner bushing module.

[0045] The steering rack module and the steering tie rod inner point bushing module are simulation function modules in Adams used to simulate actual mechanical components. They correspond to the core drive component (steering rack) and flexible connecting component (the bushing between the rack and the inner point of the steering tie rod) of the rear wheel steering system, respectively. The modules have the same geometric, kinematic and mechanical properties as the actual components.

[0046] It should be noted that the steering gear housing module directly borrows the original subframe components from the rear suspension subsystem template, and the steering tie rod module reuses the original steering tie rod components from the rear suspension subsystem template, retaining the connection relationships and mechanical properties of other original components. It only establishes a connection with the newly added steering gear rack module through the steering tie rod inner point bushing module, without changing its original constraint relationship.

[0047] In terms of the connection constraint design of each module, the steering rack module and the steering housing module (original subframe) are connected through a sliding joint constraint. This constraint limits the steering rack module to only be able to make linear reciprocating motion in a preset direction, accurately simulating the mechanical drive form of the rack in the actual rear wheel steering system, and providing a motion basis for subsequent driving force loading and rack-driven steering tie rod deflection.

[0048] The outer side of the steering rack module and the inner point bushing module of the steering tie rod are connected by flexible constraints. The inner point bushing module of the steering tie rod can accurately reproduce the elasticity, damping and stiffness characteristics of the actual bushing, avoid the simulation motion distortion caused by rigid connection, and buffer the mechanical impact during the rack drive process, so that the motion of the dynamic model is more in line with the actual mechanical working conditions.

[0049] It should be understood that by reusing native components and adding new modules incrementally, the modeling approach reduces the workload of building the rear wheel steering dynamics model, greatly improves modeling efficiency, and ensures high compatibility between the model and the native rear suspension subsystem template.

[0050] As one possible implementation, a preset rear suspension subsystem template within the Adams software is retrieved. The original subframe, steering tie rod, control arm, and other components and constraints in the template are retained. Then, a steering rack module and a steering tie rod inner bushing module are added to the original template, and the connection between the two modules is established to ensure the motion synchronization between the bushing module and the rack module. The newly added rack module is then used to establish motion constraints with the original subframe components in the template, which are represented as sliding joints in this application, thereby matching the actual motion form of the rear wheel steering system and completing the construction of the dynamic model.

[0051] It should be understood that by reusing native components and adding new modules incrementally, the workload of building the rear wheel steering dynamics model can be reduced, and the modeling efficiency can be greatly improved.

[0052] S102. Construct a control algorithm model for the rear wheel steering system using Simulink, and encapsulate the control algorithm model into a functional model unit (FMU).

[0053] Simulink is a Matlab-based visual control algorithm modeling and simulation software. The control algorithm model is a control logic model built in Simulink that can calculate the rear wheel deflection angle and driving force based on the vehicle's motion state. Its main function is to receive vehicle physical signals and output precise control commands to control the vehicle to steer based on the rear wheels.

[0054] A Functional Mock-up Unit (FMU) is a standardized functional unit that can be used across simulation software to enable model reuse and signal interaction between different simulation software. It has a unified signal interface and can be recognized by simulation software such as Adams and Simulink.

[0055] As one possible implementation, based on the control requirements of rear-wheel steering, the input variables (such as vehicle speed and front wheel steering angle), output variables (such as driving force and rear wheel steering angle), and calibration values ​​(such as proportional coefficients) of the algorithm are determined. The control algorithm logic architecture is then built in Simulink using a graphical drag-and-drop modeling approach. This involves connecting functional modules, assigning calibration values, and debugging the algorithm logic to ultimately obtain the control algorithm model. In Simulink, encapsulation parameters are configured: grtfmi.tlc is selected as the code format, and the Simulink solver parameters are set to match Adams' solver parameters (such as fixed step size). The FMU-specific encapsulation toolbox in Simulink is then called to execute the encapsulation instructions, converting the debugged control algorithm model into an FMU format file. This file contains the complete signal input / output interfaces of the control algorithm logic.

[0056] S103. In Adams' vehicle subsystem template, create sensors and actuators that match the FMU.

[0057] The sensor is used to collect physical signals from the dynamic model; the actuator is used to output signals that drive the steering rack module.

[0058] The physical signals include at least one of the following: vehicle speed, yaw rate, center of gravity sideslip angle, front wheel angle, and steering wheel angle; the sensors are respectively arranged in the body subsystem template, front suspension subsystem template, and steering subsystem template of the Adams vehicle subsystem template.

[0059] As one possible implementation, sensors are arranged in the corresponding subsystem templates according to the input requirements of the control algorithm: vehicle speed sensor, yaw rate sensor, and center of gravity sideslip angle sensor are arranged in the body subsystem; front wheel angle sensor is arranged in the front suspension subsystem; and steering wheel angle sensor is arranged in the steering subsystem. All sensors are associated with the dynamic model to ensure that the sensors can collect the physical signals of the dynamic model in real time and accurately, and that the dimensions and types of the collected signals are consistent with the FMU input. Actuators are arranged in the rear suspension subsystem template and directly associated with the steering rack module to ensure that the actuator output can directly drive the rack module. The signal interface of the actuator is configured so that its signal type and dimensions completely match the control signal at the FMU output.

[0060] S104. Associate the FMU with the dynamic model, sensors, and actuators to obtain the model of the rear wheel steering system.

[0061] The sensor is connected to the input terminal of the FMU, and the actuator is connected to the output terminal of the FMU.

[0062] As one possible implementation, open the Adams-Mechatronics mechatronics plugin and import the FMU unit generated in S202 into the Adams vehicle subsystem template. Connect all sensors arranged in S203 to the corresponding input terminals of the FMU to ensure that the physical signals collected by the sensors can be transmitted to the control algorithm model. Directly connect the output terminals of the FMU to the actuators arranged in S203 to ensure that the control signals output by the control algorithm can be transmitted to the actuators. Establish the data interaction relationship between the FMU and the dynamic model to ensure that after the actuator drives the rack module to move, the changes in the motion state of the dynamic model can be captured by the sensors in real time, forming a complete signal closed loop, thereby obtaining a complete rear wheel steering system model.

[0063] Therefore, a dynamic model of the rear-wheel steering system is constructed by adding a steering rack module and a steering tie rod inner bushing module to the rear suspension subsystem template in Adams. Then, the FMU unit corresponding to the control algorithm model of the rear-wheel steering system, as well as sensors and actuators, are constructed. The input of the FMU unit corresponds to the output of the sensor, and the output of the FMU unit corresponds to the input of the actuator. During model operation, the FMU outputs control drive signals to the actuator, which converts the control drive signals and applies them to the steering rack module of the dynamic model. The sensors collect the physical signals of the dynamic model and feed them back to the input of the FMU, thereby realizing a signal closed loop between the dynamic model and the control algorithm model, constructing a simulation model that integrates mechanics and control, and thus providing a model foundation for the simulation verification of the rear-wheel steering system.

[0064] In some embodiments, the dynamic model includes a rear-wheel steering control component for controlling the activation or deactivation of the rear-wheel steering function.

[0065] In one implementation, a rear-wheel steering control component is integrated into the constructed dynamic model. The newly added rack module, bushing module, and related motion constraints are associated with this component. The control logic of the component enables the opening and closing control of the rear-wheel steering function. After all modules are added, connected, and integrated, the model is saved as a dynamic model with rear-wheel steering function.

[0066] It should be understood that by setting up a rear-wheel steering control component, the rear-wheel steering function can be quickly opened and closed without reconstructing the dynamic model or adjusting the connection relationship of each module.

[0067] In some embodiments, the rear-wheel steering control component is a simulation module integrated into the Adams rear suspension dynamics model, containing mutually exclusive activation and suppression sub-components. The activation and deactivation of the rear-wheel steering function are achieved through parameter switching of a single control variable. Therefore, when the rear-wheel steering control component is activated, the inner point of the steering tie rod module is connected to the outer side of the steering gear rack module via the steering tie rod inner point bushing module; or, when the rear-wheel steering control component is deactivated, the inner point of the steering tie rod module is connected to the steering gear housing module.

[0068] Specifically, the opening and closing of the rear wheel steering control component can be controlled by a control variable. When the control variable triggers the rear wheel steering control component to enter the active state, its built-in activation sub-component takes effect. All newly added components and constraints related to rear wheel steering, such as the steering rack, the inner bushing of the steering tie rod, and the sliding pair between the rack and the steering housing, are activated. The inner point of the steering tie rod and the steering rack form a flexible connection through the bushing. The rack can drive the steering tie rod to deflect through linear movement, thereby realizing the rear wheel steering function.

[0069] When the control variable triggers the rear wheel steering control component to enter the closed state, its built-in suppression sub-component takes effect, all newly added components and constraints related to rear wheel steering are suppressed, the inner point of the steering tie rod and the steering gear housing (original subframe) are restored to the original rigid connection structure, the rear suspension model is completely restored to the original architecture without rear wheel steering function, and all the movement processes of the original suspension can be realized normally.

[0070] For example, the control variable is defined as rws_on. When rws_on is 1, the rear-wheel steering function is enabled; when rws_on is 0, the rear-wheel steering function is disabled. By controlling the opening and closing of the rear-wheel steering control component through the control variable, the rear-wheel steering function can be quickly switched, improving the convenience of model operation.

[0071] It should be noted that the values ​​of the control variables in this application can also be controlled based on the physical signals of the sensors. By linking the control variable rws_on with the physical signals collected by the sensors, when the physical signals indicate that the vehicle is in a steering condition, the control variable rws_on is automatically assigned a value of 1, that is, the rear wheel steering function is automatically activated, thereby realizing the automatic operation of the rear wheel steering function without manual intervention.

[0072] It should be understood that this method of adjusting the connection relationship of each component module of the rear wheel steering system through the rear wheel steering control component does not change the basic components and constraint relationship of the original rear suspension model during the control process. The function is switched only by switching the connection relationship of each module, which improves the ease of operation and ensures the compatibility of the model with Adams' original system template.

[0073] In some embodiments, building a model of the rear-wheel steering system can provide support for debugging the control algorithm of the rear-wheel steering system. Therefore, as... Figure 2 As shown, the above method also includes: S201. Import the vehicle's motion parameters under different operating conditions into the model of the rear wheel steering system, and apply driving force to the steering rack.

[0074] The working conditions include at least one of the following: U-turn in place, double lane shifting; The motion parameters of a vehicle under different operating conditions are the driving state parameters of the vehicle under different driving conditions, such as vehicle speed, steering wheel angle, driving path, lane change angle, etc., which need to be consistent with the actual driving state of the vehicle under the corresponding operating conditions.

[0075] As one possible implementation, the motion parameters for scenarios such as U-turns and double lane changes are determined, converted according to the parameter format of the Adams simulation software, and then imported into the Adams vehicle subsystem simulation environment to load the scenarios. This allows the model to perform simulations under driving conditions consistent with reality, ensuring the realism of the simulation. A driving force is applied to the steering rack based on a preset functional relationship; and / or, a driving force is applied to the steering rack based on the signal output by the FMU.

[0076] In one possible implementation, a preset function (Step / Sin function) is configured for the steering rack in Adams, so that the driving force generated by the function acts directly on the steering rack, driving the rack to move and thus causing the rear wheels to deflect.

[0077] In another possible implementation, Adams is controlled to interact with the FMU, which calculates and outputs a precise driving force control signal based on the imported working condition motion parameters through its internal control algorithm. This signal is transmitted to the actuator in Adams, which converts the signal into driving force and applies it to the steering rack, driving the rack to move and thus causing the rear wheels to deflect.

[0078] It should be understood that applying driving force to the steering rack through preset functional relationships and / or signals output by the FMU allows for flexible application of driving force under different simulation verification objectives, adapting to varying simulation requirements. Applying driving force based on preset functional relationships allows for independent driving of the rack motion, independent of the control algorithm, enabling rapid verification of the kinematic characteristics of mechanical components such as the steering rack and tie rod. Applying driving force based on the FMU output signal can reproduce the control logic of the control algorithm and mechanical structure in an actual vehicle, accurately verifying the matching degree between the control algorithm output and the mechanical system.

[0079] S202. Compare the steering parameters of the rear wheel steering control component when it is in the on and off states to obtain the test results of the rear wheel steering system.

[0080] The test results characterize the improvement effect of the rear-wheel steering system on vehicle steering performance, and the steering parameters are the basis for verifying the effectiveness of the rear-wheel steering system. Steering parameters include at least one of the following: turning radius and yaw rate. The turning radius is the radius of rotation of the vehicle when turning, used to measure the vehicle's agility. The smaller the turning radius, the more agile the vehicle is at low speeds, and the better it is suited for scenarios such as parking in tight spaces and making U-turns on narrow roads. The yaw rate is the angular velocity of the vehicle about its vertical axis perpendicular to the ground, used to measure the vehicle's stability. The smaller the yaw rate amplitude, the more stable the vehicle is when turning / changing lanes, and the less prone it is to fishtailing, lateral drift, or other phenomena.

[0081] As one possible implementation, keeping the motion parameters and driving force imported in S301 unchanged, the rear-wheel steering control component is switched to the off state, the simulation model is run, and after the simulation stabilizes, the steering parameters in this state (such as the turning radius in a U-turn scenario) are recorded. In the same simulation environment, only the rear-wheel steering control component is switched to the on state, the simulation model is run again, the steering parameters are recorded according to the same acquisition standards, and the data is saved. A quantitative comparative analysis of the same steering parameters in the two states is performed to calculate the performance improvement of the rear-wheel steering system and obtain the test results.

[0082] For example, when making a U-turn in place, keeping the vehicle speed, steering wheel full angle motion parameters and driving force unchanged, the turning radius of the vehicle is 5m when the rear wheel steering control component is off, and the turning radius of the vehicle is reduced to 4m when switched to the on state, which is a significant reduction in the turning radius.

[0083] Under double lane change conditions, while maintaining constant vehicle speed, fixed lane change angle, and driving force, the yaw rate amplitude of the vehicle is greater when the rear wheel steering control component is turned off than when it is switched on.

[0084] Therefore, by importing the vehicle's motion parameters under different operating conditions into the model of the rear wheel steering system and applying driving force to the steering rack, the steering parameters of the rear wheel steering control component in the on and off states are compared to obtain the test results of the rear wheel steering system. The performance of the rear wheel steering system can be verified under multiple operating conditions in a virtual simulation environment.

[0085] The following example illustrates this application.

[0086] First, a multibody dynamics model for rear-wheel steering is constructed.

[0087] Figure 3 This is a wireframe diagram of the H-arm suspension template for the newly added rear-wheel steering system. The steering rack S13 and steering tie rod bushing S15 are new components added to the original H-arm rear suspension system to simulate the geometric motion of the rear-wheel steering gear. The sliding joint connecting the steering rack S13 and the steering housing S14, as well as the driving force on the sliding joint, are not shown. The constructed control variables can control the opening and closing of the rear-wheel steering system, and the closed state does not affect the normal simulation of the original model. The detailed modeling process is described below: The steering rack component and its geometry are established by creating the two (left and right) inner points of the steering tie rod S12. Then, a translational sliding pair connecting the steering rack S13 and the steering housing S14 is established, where the steering housing S14 borrows the subframe component. A bushing S15 connecting the steering tie rod S12 and the steering rack S13 is then created at the inner point of the steering tie rod. The driving force is created based on the translational pair, and the driving form is displacement driving. The driving force can be driven by a preset functional relationship (such as the Step function or the Sin function). The driving force can also be driven by the actuator signal of the control system established later. This is used to study the impact of four-wheel steering on the overall vehicle performance. Next, control groups rws_active and rws_inactive are created, which contain the components of the rear wheel steering system. The control group rws_active contains the newly created steering rack component, bushing S15, sliding joint and its driving force. The control group rws_inactive contains the ball joint that connects the original model to the steering tie rod S12 and the subframe S14. The activation and deactivation of the control groups are determined by the control variable rws_on.

[0088] Additionally, a parameter variable `rws_on` is created to control the rear-wheel steering system's on / off state. When the variable is set to 1, the rear-wheel steering mode is enabled, the control component `rws_active` is activated, and its components are in an active state. `rws_inactive` is disabled, and its components are also disabled. When the variable is set to 0, the rear-wheel steering mode is disabled. The activation and deactivation of the control component switch between each other. In this mode, it will not affect the normal execution of other functions of the native model.

[0089] Secondly, the control algorithm is encapsulated into an FMU unit.

[0090] A rear-wheel steering control algorithm was constructed using Simulink, and then combined with Adams to build an electromechanical co-engineered rear-wheel steering control model. Extreme steering conditions were simulated in a virtual environment to verify the impact of rear-wheel steering on vehicle stability and responsiveness. When constructing the algorithm model, the input and output variables and calibrated values ​​must be clearly defined to correspond to the sensors and actuators of the Adams mechanical system, enabling bidirectional signal interaction. This co-simulation method is simple, logically clear, and easy to operate, greatly improving development efficiency and model stability, and also enabling data-driven algorithm development. Because the control methods, control logic, and adjustment strategies of different control algorithms vary significantly, they can be studied as independent modules and are not described in detail in this application.

[0091] The following is in conjunction with the appendix Figure 4 Detailed introduction to the FMU unit packaging process: Based on the existing control algorithm, first define the input and output variables and calibration values. Compile the model in the Simulink environment. If warnings or errors occur during compilation, re-verify the accuracy of the control algorithm and the compliance of the statements. Simultaneously check whether the model and calibration value formats have been converted to ordinary variables in the Matlab environment. FMU unit encapsulation does not support data dictionary formats. Only after the model can be compiled normally should model settings be performed. Select the grtfmi.tlc code format, which correctly configures Simulink to generate FMU units using grtfmi.tlc as the object file. Next, select the FMI tool version as needed. If the settings panel does not have an FMI tool version selection, install the KMI kit tool. If it does, select the CMake compiler version; choose any version as needed. If there is no CMake option, install the CMake compilation environment and Visual Studio compiler. Then, set the Simulink solver type and step size, selecting a fixed step size and an accuracy of 0.001 (set as needed). This process directly affects the accuracy, real-time performance, and compatibility with other tools of the simulation results and must be compatible with the Adams solver. Next, in the settings panel, select the optimization level according to the algorithm requirements to control the virtual calibration of the algorithm. Finally, generate the FMU unit using SimulinkCoder. At this point, the FMU unit encapsulation is complete, and it can be called by Adams-Mechatronics to create control templates.

[0092] Next, a control algorithm model was created based on Adams-Mechatronics.

[0093] Building the rear-wheel steering mechanical control module using the Adams-Mechatronics plugin requires creating a control system within the Adams-Car template, importing FMU units to generate an ESL file, adjusting parameters using the ESL file, verifying that input and output variables match the corresponding Simulink interface signals, and generating the control system template. Simultaneously, based on existing vehicle subsystem templates, control system sensors (corresponding to Simulink control model input signals) and control system actuators (corresponding to Simulink control model output signals) are created to achieve data closure. The modified template is then saved as a new template to create variant subsystems for the vehicle assembly. Finally, the control system subsystem, vehicle component subsystems, and the vehicle assembly are built in the Adams-Car standard interface. Output and input signals are associated in the Mechatronics signal manager, signal dimensions are defined, and ultimately, a mechatronics-controlled vehicle model is generated.

[0094] The following is combined Figure 5 and Figure 6 Detailed introduction to the modeling process of electromechanical integrated control systems: like Figure 5 As shown, first, create a new control system template (control_system) in the Adams-car template interface, and select the Adams Mechatronics plugin in the plugin management. Next, create a new control system. The main parameters of the control system depend on the ESL file for generation. If an ESL file exists in the system file, it checks whether the ESL was converted from an FMU unit. If so, the system automatically extracts / fills in the input / output signals specified in the ESL file, and then confirms whether the input / output signals are consistent with the signals defined in Simulink, thus generating the control template. If an ESL file does not exist in the system file, it can be generated using Adams. If the ESL is not converted from an FMU unit, it can be directly converted from a DLL file. You can then directly view the input / output information in the ESL file and manually fill in the input / output quantity / content.

[0095] Figure 6 This diagram illustrates the "mechanical-control" system architecture, primarily describing the Adams-FMU data flow closed-loop process. Based on the encapsulated FMU unit, the sensor signals of the Adams multibody dynamics model (i.e., the mechanical system) correspond one-to-one with the control input signals of the Simulink control algorithm (i.e., the control system). The control algorithm then analyzes the signals to obtain the control output signals, which correspond to the actuator signals of the mechanical system, driving the rear wheels to complete the corresponding steering angle. The FMU unit and the Mechatronics plugin serve as the data exchange medium, enabling bidirectional data interaction.

[0096] Furthermore, based on the subsystem templates of the original model, control system sensors are created. For example, vehicle speed, yaw rate, and center of gravity sideslip angle sensors are created in the body subsystem template; front wheel angle sensors are created in the front suspension subsystem template; and steering wheel angle sensors are created in the steering subsystem template. Simultaneously, a control system actuator is created in the rear suspension template. The driving force of the rear wheel steering system references the signal from this actuator, using displacement loading to drive the steering rack to move and obtain the corresponding rear wheel angle. When creating sensors and actuators, the signal dimensions must be unified, and the modified template file is saved as a new subsystem template to create variant subsystems for the vehicle assembly.

[0097] After creating the required subsystem templates, construct the control subsystem, vehicle component subsystems, and the complete vehicle assembly in the Adams-Car standard interface. Connect the corresponding signals of the "mechanical-control" system through the Mechatronics signal manager. Control input signals can connect to mechanical sensor signals and other control system output signals, while control output signals can connect to mechanical actuator signals and other control system input signals. Finally, a mechatronics integrated control vehicle model is generated.

[0098] Finally, based on a high-precision working condition verification system, the effectiveness of the configuration of the rear-wheel steering system control model was verified.

[0099] The vehicle model demonstrated beneficial effects under extreme conditions such as U-turns on narrow roads, high-speed lane changes, and entering and exiting ramps. Figure 7 This refers to the ability to control the vehicle's yaw rate by turning the rear wheel steering function on or off during double lane change operations. Figure 7 In the figure, the horizontal axis represents time and the vertical axis represents the yaw rate amplitude. The results show that in this vehicle model, the yaw rate amplitude when the rear wheel steering system is on is significantly less than that when the rear wheel steering system is off, proving that the rear wheel steering control system is effective.

[0100] The foregoing primarily describes the solutions provided by the embodiments of the present invention from a methodological perspective. To achieve the aforementioned functions, the modeling device or electronic device for the rear-wheel steering system includes hardware structures and / or software modules corresponding to the execution of 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 disclosed herein, the present invention 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 the present invention.

[0101] According to the above method, the modeling device or electronic device for a rear-wheel steering system can be exemplarily divided into functional modules. For example, the modeling device or electronic device for a rear-wheel steering system may include functional modules corresponding to each functional division, or two or more functions may be integrated into one processing module. The integrated module can be implemented in hardware or as a software functional module. It should be noted that the module division in the embodiments of the present invention is illustrative and only represents one logical functional division; other division methods may be used in actual implementation.

[0102] Reference Figure 8The rear wheel steering system modeling device 800 provided in this embodiment of the invention includes: a first building unit 801, a second building unit 802, a third building unit 803, and a processing unit 804.

[0103] The first building unit 801 is used to construct a dynamic model of the rear wheel steering system by adding a steering rack module and a steering tie rod inner point bushing module to the rear suspension subsystem template of the vehicle model in Adams; wherein, the steering rack module and the steering tie rod inner point bushing module are connected; the steering rack module is used to drive the rear wheels of the vehicle model to steer.

[0104] The second building unit 802 is used to build the control algorithm model of the rear wheel steering system through Simulink and encapsulate the control algorithm model into a functional model unit (FMU).

[0105] The third building block 803 is used to create sensors and actuators that match the FMU in Adams' vehicle subsystem template; the sensors are used to acquire physical signals from the dynamic model; the actuators are used to output signals that drive the steering rack module.

[0106] The processing unit 804 is used to associate the FMU with the dynamic model, sensors and actuators to obtain a model of the rear wheel steering system, wherein the sensors are connected to the input end of the FMU and the actuators are connected to the output end of the FMU.

[0107] Furthermore, the dynamic model includes: a steering gear housing module and a steering tie rod module; the inner side of the steering gear rack module is connected to the steering gear housing module; the outer side of the steering gear rack module is connected to the steering tie rod module through the steering tie rod inner bushing module.

[0108] Furthermore, the dynamic model includes a rear-wheel steering control component, which is used to control the activation or deactivation of the rear-wheel steering function.

[0109] Furthermore, when the rear wheel steering control assembly is activated, the inner point of the steering tie rod module is connected to the outer side of the steering rack module through the steering tie rod inner point bushing module; or, when the rear wheel steering control assembly is deactivated, the inner point of the steering tie rod module is connected to the steering housing module.

[0110] Furthermore, the aforementioned processing unit 702 is also used to import the vehicle's motion parameters under different operating conditions into the model of the rear wheel steering system and apply driving force to the steering rack module; the operating conditions include at least one of the following: U-turn in place and double lane change; the steering parameters of the rear wheel steering control component in the on and off states are compared to obtain the test results of the rear wheel steering system; the steering parameters include at least one of the following: turning radius and yaw rate; the test results are used to characterize the improvement effect of the rear wheel steering system on the vehicle's steering performance.

[0111] Furthermore, the aforementioned processing unit 702 is specifically used to apply driving force to the steering rack module based on a preset functional relationship; and / or to apply driving force to the steering rack module based on the signal output by the FMU.

[0112] Furthermore, the physical signals include at least one of the following: vehicle speed, yaw rate, center of gravity sideslip angle, front wheel angle, and steering wheel angle; the sensors are respectively arranged in the body subsystem template, front suspension subsystem template, and steering subsystem template of the Adams vehicle subsystem template.

[0113] like Figure 9 As shown, the electronic device 900 provided in this embodiment of the invention includes, but is not limited to, a processor 901 and a memory 902.

[0114] The aforementioned memory 902 is used to store the executable instructions of the aforementioned processor 901. It is understood that the processor 901 is configured to execute instructions to implement the modeling method for the rear-wheel steering system in the above embodiments.

[0115] It should be noted that those skilled in the art will understand that Figure 9 The electronic device structure shown does not constitute a limitation on the electronic device; the electronic device may include, but is not limited to, other electronic devices. Figure 9 This may indicate more or fewer components, or a combination of certain components, or a different arrangement of components.

[0116] Processor 901 is the control center of the electronic device. It connects various parts of the electronic device via various interfaces and lines. By running or executing software programs and / or modules stored in memory 902, and by calling data stored in memory 902, it performs various functions and processes data, thereby providing overall monitoring of the electronic device. Processor 901 may include one or more processing units. Optionally, processor 901 may integrate an application processor and a modem processor. The application processor mainly handles the operating system, user interface, and applications, while the modem processor mainly handles wireless communication. It is understood that the modem processor may not be integrated into processor 901.

[0117] The memory 902 can be used to store software programs and various data. The memory 902 may primarily include a program storage area and a data storage area. The program storage area may store the operating system, application programs required by at least one functional module (such as a determination unit, processing unit, etc.), etc. Furthermore, the memory 902 may include high-speed random access memory, and may also include non-volatile memory, such as at least one disk storage device, flash memory device, or other volatile solid-state storage device.

[0118] In an exemplary embodiment, a vehicle is also provided, including the electronic equipment described above.

[0119] In an exemplary embodiment, a computer-readable storage medium including instructions is also provided, such as a memory 902 including instructions, which can be executed by a processor 901 of an electronic device 900 to implement the methods in the above embodiments.

[0120] In actual implementation, Figure 8 The functions of each module can be provided by Figure 9 The processor 901 calls the computer program stored in the memory 902 to implement the process. The specific execution process can be found in the description of the method section in the previous embodiment, and will not be repeated here.

[0121] Optionally, the computer-readable storage medium may be a non-transitory computer-readable storage medium, such as a read-only memory (ROM), random access memory (RAM), CD-ROM, magnetic tape, floppy disk, and optical data storage device.

[0122] In an exemplary embodiment, the present invention also provides a computer program product including one or more instructions, which can be executed by a processor 901 of an electronic device to perform the methods described above.

[0123] It should be noted that when one or more instructions in the computer-readable storage medium or computer program product are executed by the processor of an electronic device, they implement the various processes of the above method embodiments and achieve the same technical effect as the above method. To avoid repetition, they will not be described again here.

[0124] Through the above description of the embodiments, those skilled in the art can clearly understand that, for the sake of convenience and brevity, only the division of the above functional modules is used as an example. In actual applications, the above functions can be assigned to different functional modules as needed, that is, the internal structure of the device can be divided into different functional modules to complete all or part of the functions described above.

[0125] In the several embodiments provided by this invention, it should be understood that the disclosed apparatus and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative; for instance, the division of modules or 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 device, 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, mechanical, or other forms.

[0126] The units described as separate components may or may not be physically separate. A component shown as a unit can be one or more physical units; that is, it can be located in one place or distributed in multiple different locations. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0127] Furthermore, the functional units in the various embodiments of the present invention 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 functional unit.

[0128] If the integrated unit is implemented as a software functional unit and sold or used as an independent product, it can be stored in a readable storage medium. Based on this understanding, the technical solution of the embodiments of the present invention, 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 software product is stored in a storage medium and includes several instructions to cause a device (which may be a microcontroller, chip, etc.) or processor to execute all or part of the steps of the methods of the various embodiments of the present invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, ROM, RAM, magnetic disks, or optical disks.

[0129] The above embodiments are merely preferred embodiments provided to fully illustrate the present invention, and the scope of protection of the present invention is not limited thereto. Equivalent substitutions or modifications made by those skilled in the art based on the present invention are all within the scope of protection of the present invention.

Claims

1. A modeling method for a rear-wheel steering system, characterized in that, include: A dynamic model of the rear wheel steering system is constructed by adding a steering rack module and a steering tie rod inner point bushing module to the rear suspension subsystem template of the vehicle model in Adams; wherein, the steering rack module and the steering tie rod inner point bushing module are connected; the steering rack module is used to drive the rear wheels of the vehicle model to steer; The control algorithm model of the rear wheel steering system is constructed using Simulink, and the control algorithm model is encapsulated as a functional model unit (FMU). In the Adams vehicle subsystem template, sensors and actuators matching the FMU are created; the sensors are used to acquire physical signals from the dynamics model; the actuators are used to output signals that drive the steering rack module. The FMU is associated with the dynamic model, the sensor, and the actuator to obtain the model of the rear wheel steering system, wherein the sensor is connected to the input terminal of the FMU and the actuator is connected to the output terminal of the FMU.

2. The method according to claim 1, characterized in that, The dynamic model includes: a steering gear housing module and a steering tie rod module; The inner side of the steering rack module is connected to the steering housing module; The outer side of the steering rack module is connected to the steering tie rod module via the inner bushing module of the steering tie rod.

3. The method according to claim 1 or 2, characterized in that, The dynamic model includes a rear-wheel steering control component, which is used to control the activation or deactivation of the rear-wheel steering function.

4. The method according to claim 3, characterized in that, When the rear wheel steering control assembly is activated, the inner point of the steering tie rod module is connected to the outer side of the steering rack module via the inner point bushing module of the steering tie rod; or, With the rear wheel steering control assembly off, the inner point of the steering tie rod module is connected to the steering gear housing module.

5. The method according to claim 3, characterized in that, The method further includes: The motion parameters of the vehicle under different operating conditions are imported into the model of the rear wheel steering system, and a driving force is applied to the steering rack module; the operating conditions include at least one of the following: U-turn in place, double lane change. By comparing the steering parameters of the rear wheel steering control component in the on and off states, the test results of the rear wheel steering system are obtained; the steering parameters include at least one of the following: turning radius and yaw rate; the test results are used to characterize the improvement effect of the rear wheel steering system on vehicle steering performance.

6. The method according to claim 5, characterized in that, Applying a driving force to the steering rack module includes: The driving force is applied to the steering rack module based on a preset functional relationship; and / or The driving force is applied to the steering rack module based on the signal output by the FMU.

7. The method according to claim 1, characterized in that, The physical signals include at least one of the following: vehicle speed, yaw rate, center of gravity sideslip angle, front wheel angle, and steering wheel angle; the sensors are respectively arranged in the body subsystem template, front suspension subsystem template, and steering subsystem template of the Adams vehicle subsystem template.

8. A modeling device for a rear-wheel steering system, characterized in that, The device includes: The first building unit is used to construct a dynamic model of the rear wheel steering system by adding a steering rack module and a steering tie rod inner point bushing module to the rear suspension subsystem template of the vehicle model in Adams; wherein, the steering rack module and the steering tie rod inner point bushing module are connected; the steering rack module is used to drive the rear wheels of the vehicle model to steer; The second building unit is used to build the control algorithm model of the rear wheel steering system through Simulink and encapsulate the control algorithm model into a functional model unit (FMU). The third building unit is used to create sensors and actuators that match the FMU in the Adams vehicle subsystem template; the sensors are used to acquire physical signals from the dynamic model; the actuators are used to output signals that drive the steering rack module to move. The processing unit is used to associate the FMU with the dynamic model, the sensor and the actuator to obtain the model of the rear wheel steering system, wherein the sensor is connected to the input terminal of the FMU and the actuator is connected to the output terminal of the FMU.

9. The apparatus according to claim 8, characterized in that, The dynamic model includes a rear-wheel steering control component, which is used to control the activation or deactivation of the rear-wheel steering function.

10. An electronic device, characterized in that, include: processor; Memory used to store the processor's executable instructions; The processor is configured to execute the instructions to implement the method as described in any one of claims 1 to 7.

11. A computer-readable storage medium, characterized in that, When the computer-executable instructions stored in the computer-readable storage medium are executed by the processor of the electronic device, the electronic device is capable of performing the method as described in any one of claims 1 to 7.

12. A computer program product, characterized in that, When the computer program product is run in an electronic device, it causes the electronic device to perform the method as described in any one of claims 1 to 7.

Images