Transverse control test method and system for an electric power steering system

Abstract

The embodiment of the application discloses a kind of transverse control test method and system of electric power steering system, it is related to EPS test technical field, including: using trajectory tracking controller, vehicle state observer, to be measured EPS, torque generator constructs test system;Vehicle state observer is calculated vehicle transverse state matrix, input trajectory tracking controller calculates vehicle front wheel angle and rear wheel angle, then again calculate target steering angle, target speed, and front wheel back positive resistance torque, and to be measured EPS executes the transverse control test of EPS under the action of simulating steering resistance.It is more close to the test result of real car by establishing vehicle mathematical model, carrying out dynamic trajectory tracking and vehicle state observation, more real simulation real car working condition, solve the problem that bench test result and real car effect difference is big, can carry out EPS transverse control function's function effectiveness, performance precision test before real car landing.

Description

Technical Field

[0001] This invention relates to the field of EPS electric power steering system testing technology, and in particular to a lateral control testing method and system for an electric power steering system. Background Technology

[0002] The lateral control function of EPS (Electric Power Steering) is an important component of intelligent driving assistance systems, such as Lane-Keeping Assist (LKA) and Automated Parking Assist (APA). These systems automatically correct the vehicle's direction through the steering system to assist the driver and are increasingly widely used. As the execution unit for lateral control, the response time and steering error of the EPS system directly affect the function and performance of lateral control, and also impact driving comfort.

[0003] Lateral control function and performance testing of EPS systems is often conducted on a test bench. This involves setting up the EPS lateral control system on the bench and transmitting commands for the target steering angle and speed to the EPS via CAN messages, thereby testing the lateral control function, response time, and angle error. However, bench testing does not consider vehicle parameters, specific operating conditions, and vehicle trajectory, leading to significant discrepancies between test results and verification effects from real-vehicle testing. This means that parameters obtained from bench lateral testing cannot be directly applied to real vehicles, and parameters obtained after recalibration and testing on real vehicles are also unsuitable for bench testing, impacting the efficiency and accuracy of EPS lateral control testing. Summary of the Invention

[0004] This invention provides a method and system for testing the lateral control of an electric power steering system, in order to solve the technical problem that the bench test results of EPS lateral control differ too much from the actual vehicle verification results, making it impossible to apply to actual vehicles.

[0005] In a first aspect, embodiments of the present invention provide a method for testing the lateral control of an electric power steering system, comprising:

[0006] S101, respectively establish a trajectory tracking controller and a vehicle state observer, which together with the EPS system under test and the torque generator form an EPS lateral control test system;

[0007] S102, the vehicle lateral state matrix is ​​calculated based on the vehicle dynamics model using the vehicle state observer, and the front wheel steering angle and rear wheel steering angle are calculated based on the deviation matrix between the vehicle lateral state matrix and the vehicle target trajectory using the trajectory tracking controller.

[0008] S103, the vehicle state observer calculates the target steering angle, target speed and front wheel return resistance torque of the vehicle lateral control based on the front wheel steering angle and rear wheel steering angle. The torque generator generates simulated steering resistance based on the front wheel return resistance torque and applies it to the mechanical assembly of the EPS system under test.

[0009] S104, the EPS under test controls its mechanical assembly to perform steering assist control under the action of simulated steering resistance according to the target steering angle and target speed, so as to conduct dynamic testing of the EPS's lateral control function, response time and angle error.

[0010] Secondly, embodiments of the present invention provide a lateral control test system for an electric power steering system, comprising:

[0011] The trajectory tracking control module is used to calculate the front wheel steering angle and rear wheel steering angle of the vehicle based on the vehicle lateral state matrix and the vehicle target trajectory deviation matrix.

[0012] The vehicle state observation module is used to calculate the vehicle's lateral state matrix based on the vehicle dynamics model and form a closed-loop feedback with the trajectory tracking control module. It calculates the target steering angle, target speed, and front wheel positive resistance torque of the vehicle's lateral control based on the front wheel steering angle and rear wheel steering angle.

[0013] A torque generator is used to generate simulated steering resistance based on the positive resistance torque of the front wheels, and then apply it to the mechanical assembly of the EPS system under test.

[0014] The EPS module under test includes an electronic control unit connected to a vehicle status observation module and a mechanical assembly connected to a torque generator. The electronic control unit is configured to receive a target steering angle and a target speed, and control the mechanical assembly to perform steering assist control under the action of simulated steering resistance.

[0015] Thirdly, embodiments of the present invention provide an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the above-described lateral control test method for the electric power steering system.

[0016] Fourthly, embodiments of the present invention provide a computer-readable storage medium, characterized in that it stores a computer program thereon, which, when executed by a processor, implements the above-described lateral control test method for an electric power steering system.

[0017] This invention provides a method and system for testing the lateral control of an electric power steering (EPS) system. Through a closed-loop feedback logic formed by a vehicle state observer and a vehicle trajectory tracking controller, it generates target steering commands and corresponding simulated steering resistance in real time based on a vehicle dynamics model. The resistance torque of the front wheels returning to positive is output to a torque generator via a CAN signal. The torque generator produces a counter-torque corresponding to the simulated steering resistance, which is then converted into a stress torque applied to both ends of the steering gear of the EPS system's mechanical assembly. Based on the output steering wheel angle and yaw rate, the target steering angle and speed for EPS lateral control can be obtained, and lateral control testing is performed under the action of simulated steering resistance. By establishing a vehicle mathematical model, dynamic trajectory tracking and vehicle state observation are performed, covering different driving routes and interference conditions. The testing is comprehensive, more realistically simulating real-vehicle conditions, and obtaining test results closer to those of a real vehicle. This solves the problem of large discrepancies between bench test results and real-vehicle performance. It allows for testing the functional effectiveness and performance accuracy of the EPS lateral control function before the actual vehicle is deployed. It is low-cost, easy to implement, requires little space, and is easy to deploy, making it suitable for testing during the R&D and production stages of EPS systems. Attached Figure Description

[0018] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings:

[0019] Figure 1 This is a flowchart of a lateral control test method for an electric power steering system according to Embodiment 1 of the present invention;

[0020] Figure 2 This is a schematic diagram of the lateral control test system for an electric power steering system according to Embodiment 2 of the present invention;

[0021] Figure 3 This is a structural diagram of the electronic device described in Embodiment 3 of the present invention. Detailed Implementation

[0022] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, the accompanying drawings show only the parts relevant to the present invention, and not all of the structures.

[0023] Example 1

[0024] Figure 1This is a flowchart of a lateral control test method for an electric power steering system according to Embodiment 1 of the present invention. It establishes a closed-loop test system simulating the lateral control conditions of a real vehicle by introducing a vehicle state observer simulating the vehicle's lateral motion state and a trajectory tracking controller simulating the vehicle's driving trajectory. The specific steps include:

[0025] S101 establishes a trajectory tracking controller and a vehicle state observer, which together with the EPS system under test and the torque generator form an EPS lateral control test system.

[0026] In an industrial control computer, mathematical models for a trajectory tracking controller to simulate vehicle driving trajectory and a vehicle state observer to simulate vehicle lateral motion are established through software programming. This industrial control computer is connected to the electronic control unit (ECU) and torque generator of the EPS system under test via a CAN bus. It sends vehicle lateral control commands to the ECU and torque commands simulating wheel return force to the torque generator, together forming the EPS lateral control test system. The constructed vehicle state observer has the function of acquiring vehicle motion state parameters in real time during vehicle operation. The acquired vehicle motion state parameters include: vehicle weight. ( ), vehicle yaw moment of inertia ( Front tire lateral stiffness ( Rear tire lateral stiffness ( ), distance from the vehicle's center of gravity to the center of the front wheel ( ), distance from the vehicle's center of gravity to the rear wheel center ( Initial longitudinal speed (k Initial yaw angle of the vehicle (°), Initial yaw rate of the vehicle ( All of these can be determined based on the initial state of the test vehicle. (Set vehicle coordinates) A sinusoidal road was set up for testing, based on the actual test road environment, and the vehicle was made to travel along a sinusoidal route at a constant speed. The lateral length of the road was 500m. The longitudinal displacement of the vehicle over time was recorded. satisfy Let t be time, then the vehicle's lateral travel coordinates satisfy... Therefore, the desired path curvature radius *r* of the vehicle during the experimental driving process can be obtained. Based on the relationship between the road curvature radius and lateral and longitudinal displacements and their velocities, this can be expressed as the formula:

[0027]

[0028] in, For the longitudinal speed of the vehicle, The lateral speed of the vehicle. For the longitudinal acceleration of the vehicle, This represents the vehicle's lateral acceleration. The desired yaw angle of the vehicle during the experimental driving process. ( ) and desired yaw rate ( According to the formula for converting angles and radians, it can be expressed as:

[0029]

[0030] in, Initial yaw angle of the vehicle , The initial yaw rate of the vehicle .

[0031] S102, the vehicle lateral state matrix is ​​calculated based on the vehicle dynamics model using the vehicle state observer, and the front wheel steering angle and rear wheel steering angle are calculated based on the deviation matrix between the vehicle lateral state matrix and the vehicle target trajectory using the trajectory tracking controller.

[0032] The vehicle state observer, based on a vehicle dynamics model, uses measurable real-time vehicle motion states to generate vehicle motion parameters (obtainable through on-site driving tests or historical experimental data), and calculates and outputs the vehicle's lateral state matrix X in real time. The lateral state matrix X includes lateral velocity v, yaw rate ω, lateral path offset y, and yaw angle φ, representing the vehicle's lateral motion state. This vehicle state matrix is ​​then transmitted to the trajectory tracking controller, which, based on the received lateral state matrix X and the vehicle target trajectory deviation matrix X,... b The front wheel steering angle δ_f and rear wheel steering angle δ_r of the vehicle are calculated based on the current vehicle motion state. The vehicle target trajectory deviation matrix X is also calculated. b Including the expected lateral velocity deviation v b Expected yaw rate deviation ω b Expected lateral path offset deviation y b and the deviation of the expected yaw angle φ b It is used to represent the deviation between the lateral motion state of the vehicle and the desired state.

[0033] The vehicle dynamics model includes a lateral acceleration calculation model and a yaw rate calculation model. It can calculate lateral acceleration variables and yaw rate variables based on preset lateral vehicle speed, longitudinal vehicle speed, front and rear tire lateral stiffness, distance from the vehicle's center of gravity to the center of the front and rear wheels, vehicle weight, front and rear wheel steering angles, vehicle yaw rate, and vehicle yaw moment of inertia.

[0034] Based on the vehicle's dynamic characteristics, a lateral acceleration calculation model for a vehicle state observer can be built to calculate the vehicle's lateral acceleration variables, and a yaw angle acceleration calculation model can be built to calculate the yaw angle acceleration variables. The model formula (1) is as follows:

[0035]

[0036] in, The lateral acceleration of the vehicle ( ), yaw acceleration ( ), m is the vehicle weight ( ), and These are the vehicle's lateral speed and longitudinal speed, respectively. ), yaw rate ( ), and The lateral stiffness of the front and rear tires are respectively ( This can be determined based on the tire parameters. and These are the distances from the vehicle's center of gravity to the center of the front wheel and the distances to the center of the rear wheel, respectively. ), and These are the front wheel steering angle and rear wheel steering angle (rad) of the vehicle, respectively. The yaw moment of inertia of the vehicle ( It can be set according to the vehicle's initial parameters.

[0037] The vehicle dynamics model also includes a lateral offset speed calculation model and a yaw angle error calculation model, which can calculate the lateral offset speed variable and the yaw angle error variable respectively based on preset lateral vehicle speed, longitudinal vehicle speed, vehicle yaw angle, vehicle yaw rate, and road curvature radius.

[0038] Based on the vehicle's dynamic characteristics, a lateral offset velocity calculation model for the vehicle state observer can also be built. The lateral offset velocity variable of the vehicle can be calculated based on the vehicle's yaw angle, as shown in the following formula (2):

[0039]

[0040] in, and These are the vehicle's lateral speed and longitudinal speed, respectively. ), Let yaw angle be the vehicle yaw angle (rad). And the yaw angle error calculation model, based on the vehicle yaw angle, calculates the yaw angle error variable as shown in the following formula (3):

[0041]

[0042] in, yaw rate ( ), where r is the radius of curvature of the road.

[0043] The vehicle state observer calculates the vehicle's lateral state matrix X by solving the first-order derivative equation based on the lateral acceleration calculation model, yaw angle acceleration calculation model, lateral offset velocity calculation model, and yaw angle error calculation model.

[0044] The vehicle's lateral state matrix X can be represented as a column vector as follows: The steering angle matrix Y of the front and rear wheels of the vehicle can be represented by a column vector as follows: and variables related to road curvature radius Based on the above formulas (1) to (3), a vehicle observation controller model is established as shown in the following formula (4):

[0045]

[0046]

[0047] To facilitate later controller setup, the coefficient matrix of each column vector is represented by a relationship with coefficient matrices A, B, and C. coefficient matrix coefficient matrix It can be based on the known data obtained from the vehicle's experimental driving. , , , , , Solve for coefficient matrices A, B, and C, respectively, using u and u.

[0048] The vehicle target trajectory deviation matrix is ​​calculated based on the preset vehicle coordinates, desired path coordinates, and desired path curvature radius. , where v b、 ω b、 y b、 φ bThese are the desired lateral velocity deviation, desired yaw rate deviation, desired lateral path offset deviation, and desired yaw angle deviation, representing the deviation values ​​between these four parameters and the desired trajectory. During the vehicle's experimental driving, based on the known vehicle coordinates... with expected path coordinates Desired path radius of curvature The vehicle target trajectory deviation matrix can be obtained. Expressed as:

[0049]

[0050] The trajectory tracking controller uses the vehicle's lateral state matrix X and the vehicle target trajectory deviation matrix X' to determine the trajectory. b Using the preset expected trajectory deviation matrix Q as X and X b The deviations between them are weighted, and the vehicle's front and rear wheel steering angle matrix Y is weighted using the preset trajectory control energy consumption matrix R, to construct a vehicle trajectory deviation function E containing the costate matrix P;

[0051] Ideally, a vehicle moves along a predetermined desired trajectory, but in reality, it often deviates from this trajectory. This is addressed by using matrix X to represent the vehicle's lateral motion and matrix X' to represent the deviation between the vehicle and the desired trajectory. b A vehicle trajectory deviation function E is constructed to describe the vehicle's trajectory deviation. Based on optimal control theory, it is created so that the trajectory tracking effect is optimal under optimal control. The vehicle trajectory deviation function E yields four variables—the front wheel steering angle, the rear wheel steering angle, and the output of the vehicle state observer—that determine the optimal trajectory tracking effect. The relationship between these variables. When constructing function E, to facilitate the description of the vehicle's front wheel steering angle, rear wheel steering angle, and the four variables output by the vehicle state observer... The relationship between the matrix X and the matrix X is determined by adding a costate matrix P to the function, and simultaneously using a preset expected trajectory deviation matrix Q as the basis for determining the relationship between the matrix X and the matrix X. b The differences between them are weighted to measure the deviation from the expected value in the trajectory tracking controller, and the preset trajectory control energy consumption matrix R is used to measure the energy consumption to achieve trajectory control. The front and rear wheel steering angle matrices Y of the vehicle are weighted to form the vehicle trajectory deviation function E, as shown in the following formula (5):

[0052]

[0053] Among them, the expected trajectory deviation matrix Used for the vehicle's lateral state matrix Weighted trajectory control energy consumption matrix Used for the steering angle matrix of the front and rear wheels of a vehicle. Weighting is applied. For example, based on industry practice and historical experience, as well as the actual debugging effect parameters of the corresponding EPS LKA application scenario, the weighting coefficients are set as follows: q1=1, q2=1000, q3=1000, q4=10, q5=10000, q6=0.

[0054] Based on the principle of minimizing vehicle trajectory deviation in optimal control theory, the vehicle trajectory deviation function E is derived to form the front and rear wheel steering angle matrix Y. The co-state vector P is calculated based on the vehicle lateral state matrix X. The front and rear wheel steering angles are obtained by solving the front and rear wheel steering angle matrix Y based on the co-state vector P.

[0055] Based on optimal control theory Even if the vehicle trajectory deviation is at least 0 (no deviation), the front and rear wheel steering angle matrix Y can be derived as follows (6):

[0056]

[0057] in, for The inverse matrix, for The transpose matrix. Then, based on the closed-loop feedback logic composed of the trajectory tracking controller and the vehicle state observer, the functional expression (7) of the costate vector P is constructed through two weighting coefficients:

[0058]

[0059] Where K and D are coefficient matrices. Based on the above formulas (5), (6), and (7), formulas (8-1) and (8-2) can be derived from the Riccati equation:

[0060]

[0061] Wherein, the coefficient matrix K is based on the vehicle target trajectory deviation matrix. The expression is obtained by calculating matrix K using the above equation (8-1) through an iterative algorithm (MATLAB lqr function).

[0062] From equation (8-2) above, we can obtain:

[0063]

[0064] For ease of calculation, let's assume... , , From this, the expression for the coefficient matrix D can be derived (9):

[0065]

[0066] in, and The matrix used to simplify mathematical formulas Vehicle target trajectory deviation matrix , The yaw rate is angular velocity. Let the radius of curvature of the desired path be . matrix Column 2 for The first column. Then, matrix F is calculated. and Thus, the matrix is ​​obtained. matrix parameters , , , ,matrix matrix parameters , , , Substituting equation (9) into equation (8), we obtain the formula (10) for calculating the costate matrix P:

[0067]

[0068] Based on the above optimal control theory, the expression for the steering angle matrix Y of the front and rear wheels of the vehicle can be obtained as follows (11):

[0069]

[0070] Continuing the derivation, we can obtain the steering angle of the vehicle's front wheels. and the turning angle of the vehicle's rear wheels The expressions (12-1) and (12-2) are:

[0071]

[0072]

[0073] This allows us to determine the front wheel steering angle of the vehicle. and rear wheel angle Since lateral control is based on the front wheels, the rear steering angle is always set to 0. =0.

[0074] S103, the vehicle state observer calculates the target steering angle, target speed, and front wheel return torque of the vehicle's lateral control based on the front wheel steering angle and rear wheel steering angle. The torque generator generates simulated steering resistance based on the front wheel return torque and applies it to the mechanical assembly of the EPS system under test.

[0075] The vehicle state observer receives the front and rear wheel steering angles calculated by the trajectory tracking controller, and then calculates and outputs three key control variables related to vehicle lateral control: the target steering angle θ. * Target rotational speed ω * and front wheel return torque , representing the vehicle's desired steering angle, desired yaw rate, and front wheel self-centering force under that condition, respectively. The front wheel self-centering resistance torque is sent to a torque generator via a CAN signal. The torque generator (e.g., a servo motor loading system) converts the electrical signal into a real simulated steering resistance and applies it to the mechanical assembly (such as the steering column) of the EPS system under test.

[0076] The vehicle state observer, based on the received front and rear wheel steering angles and Newton's laws and the force characteristics of the tires, calculates the front wheel lateral force, then the front wheel return torque, and finally the target steering angle θ based on the front wheel steering angle, the preset steering wheel angle, and the vehicle's gear ratio. * According to the target turning angle θ * Calculate the target rotational speed ω * .

[0077] Based on Newton's second law (the law of acceleration) and the force characteristics of tires, a positive torque is constructed for the front wheels. The expression (13):

[0078]

[0079] in, For the front wheel lateral force, The tire trail is typically 0.01-0.03m. The front wheel lateral force can be calculated based on the current lateral motion of the vehicle, as shown in the following formula (14):

[0080]

[0081] in, For vehicle quality, It is the sum of the vehicle's lateral accelerations (including the vehicle's lateral acceleration and the acceleration component formed by the vehicle's velocity in the lateral direction). For the lateral acceleration of the vehicle, For vehicle speed, Let yaw rate be angular velocity. Substituting equation (14) into equation (13) yields the front wheel return torque. The calculation formula (15) is as follows:

[0082]

[0083] The vehicle state observer can calculate the target steering angle θ based on the relationship between the vehicle's steering wheel angle, the front wheel angle, and the vehicle's transmission ratio. * That is, the desired steering angle of the vehicle under the current steering wheel control, as shown in the following formula (16):

[0084]

[0085] in, Given the transmission ratio, the selected transmission ratio for the vehicle is N=10. This is the steering angle of the vehicle's front wheels. Based on the target steering angle θ. * Calculate the target rotational speed ω using the first derivative. * : .

[0086] S104, the EPS under test controls its mechanical assembly to perform steering assist control under the action of simulated steering resistance according to the target steering angle and target speed, so as to conduct dynamic testing of the EPS's lateral control function, response time and angle error.

[0087] At this time, the electronic control unit of the EPS under test determines the target steering angle θ sent by the CAN bus. * and target rotational speed ω * The EPS motor is driven, and its mechanical assembly is controlled to perform power steering control under simulated steering resistance. By monitoring the actual response of the EPS, such as the actual steering angle and response delay, dynamic testing of the EPS's lateral control function, response time, and angle error is achieved, obtaining test results that closely approximate the performance of a real vehicle.

[0088] This embodiment utilizes a closed-loop feedback logic formed by a vehicle state observer and a vehicle trajectory tracking controller. Based on the vehicle dynamics model, it generates target steering commands and corresponding simulated steering resistance in real time. The front wheel return torque is output to a torque generator via a CAN signal. The torque generator produces a counter-torque corresponding to the simulated steering resistance, which is then converted into a stress torque applied to both ends of the steering gear of the EPS system's mechanical assembly. Based on the output steering wheel angle and yaw rate, the target steering angle and speed for EPS lateral control can be obtained, allowing for lateral control testing under simulated steering resistance. By establishing a vehicle mathematical model, dynamic trajectory tracking and vehicle state observation are performed, covering different driving routes and interference conditions. This comprehensive testing provides a more realistic simulation of real-vehicle conditions, yielding test results closer to those of a real vehicle. It solves the problem of significant discrepancies between bench test results and real-vehicle performance. It enables testing of the functional effectiveness and performance accuracy of EPS lateral control before real-vehicle deployment. It is low-cost, easy to implement, requires little space, and is easy to deploy, making it suitable for testing during the R&D and production phases of EPS systems.

[0089] Example 2

[0090] Figure 2 This is a schematic diagram of the lateral control test system for an electric power steering system according to Embodiment 2 of the present invention. The system described in this embodiment is used to implement the lateral control test method for the above-mentioned electric power steering system, specifically including:

[0091] The trajectory tracking control module is used to calculate the front wheel steering angle and rear wheel steering angle of the vehicle based on the vehicle lateral state matrix and the vehicle target trajectory deviation matrix.

[0092] The vehicle state observation module is used to calculate the vehicle's lateral state matrix based on the vehicle dynamics model and form a closed-loop feedback with the trajectory tracking control module. It calculates the target steering angle, target speed, and front wheel positive resistance torque of the vehicle's lateral control based on the front wheel steering angle and rear wheel steering angle.

[0093] A torque generator is used to generate simulated steering resistance based on the positive resistance torque of the front wheels, and then apply it to the mechanical assembly of the EPS system under test.

[0094] The EPS module under test includes an electronic control unit connected to a vehicle status observation module and a mechanical assembly connected to a torque generator. The electronic control unit is configured to receive a target steering angle and a target speed, and control the mechanical assembly to perform steering assist control under the action of simulated steering resistance.

[0095] This embodiment calculates the front and rear wheel steering angles of the vehicle based on its lateral state and target trajectory deviation using a trajectory tracking control module. A vehicle state observation module calculates various aspects of the vehicle's lateral state based on a vehicle dynamics model, forming a closed-loop feedback with the trajectory tracking controller. It calculates the target steering angle and target speed for lateral control, as well as the front wheel return resistance. A torque generator generates simulated steering resistance based on the front wheel return resistance and applies it to the mechanical assembly of the EPS system under test. The EPS module under test receives the target steering angle and target speed from the vehicle state observation module and drives the mechanical assembly to perform steering assist control testing under the simulated steering resistance. By establishing a vehicle mathematical model, dynamic trajectory tracking and vehicle state observation are performed, covering different driving routes and interference conditions. This comprehensive testing provides a more realistic simulation of real-vehicle conditions, yielding test results closer to those of a real vehicle. It solves the problem of large discrepancies between bench test results and real-vehicle performance. It allows for testing the functional effectiveness and performance accuracy of the EPS lateral control function before real-vehicle deployment. It is low-cost, easy to implement, requires little space, and is easy to deploy, making it suitable for testing during the R&D and production stages of EPS systems.

[0096] The lateral control test system for electric power steering provided in this embodiment of the invention can execute the lateral control test method for electric power steering provided in any embodiment of the invention, and has the corresponding functional modules and beneficial effects of the execution method.

[0097] Example 3

[0098] Figure 3 This is a structural diagram of an electronic device according to Embodiment 3 of the present invention. Figure 3 A block diagram is shown of an exemplary electronic device 12 suitable for implementing embodiments of the present invention. Figure 3 The electronic device 12 shown is merely an example and should not impose any limitation on the functionality and scope of use of the embodiments of the present invention.

[0099] like Figure 3 As shown, the electronic device 12 is represented in the form of a general-purpose computing device. The components of the electronic device 12 may include, but are not limited to: one or more processors or processing units 16, system memory 28, and bus 18 connecting different system components (including system memory 28 and processing unit 16).

[0100] Bus 18 represents one or more of several bus architectures, including a memory bus or memory controller, a peripheral bus, a graphics acceleration port, a processor, or a local bus using any of the various bus architectures. For example, these architectures include, but are not limited to, the Industry Standard Architecture (ISA) bus, the Micro Channel Architecture (MAC) bus, the Enhanced ISA bus, the Video Electronics Standards Association (VESA) local bus, and the Peripheral Component Interconnect (PCI) bus.

[0101] Electronic device 12 typically includes a variety of computer system readable media. These media can be any available media that can be accessed by electronic device 12, including volatile and non-volatile media, removable and non-removable media.

[0102] System memory 28 may include computer system readable media in the form of volatile memory, such as random access memory (RAM) 30 and / or cache memory 32. Electronic device 12 may further include other removable / non-removable, volatile / non-volatile computer system storage media. By way of example only, storage system 34 may be used to read and write non-removable, non-volatile magnetic media (… Figure 3 Not shown; usually referred to as a "hard drive"). Although Figure 3Not shown, a disk drive for reading and writing to a removable non-volatile disk (e.g., a "floppy disk") and an optical disk drive for reading and writing to a removable non-volatile optical disk (e.g., a CD-ROM, DVD-ROM, or other optical media) may be provided. In these cases, each drive may be connected to bus 18 via one or more data media interfaces. System memory 28 may include at least one program product having a set (e.g., at least one) of program modules configured to perform the functions of the embodiments of the present invention.

[0103] A program / utility 40 having a set (at least one) of program modules 42 may be stored, for example, in system memory 28. Such program modules 42 include, but are not limited to, an operating system, one or more application programs, other program modules, and program data. Each or some combination of these examples may include an implementation of a network environment. Program modules 42 typically perform the functions and / or methods described in the embodiments of the present invention.

[0104] Electronic device 12 can also communicate with one or more external devices 14 (e.g., keyboard, pointing device, display 24, etc.), and with one or more devices that enable a user to interact with the electronic device 12 / server / computer, and / or with any device that enables the electronic device 12 to communicate with one or more other computing devices (e.g., network card, modem, etc.). This communication can be performed through input / output (I / O) interface 22. Furthermore, electronic device 12 can also communicate with one or more networks (e.g., local area network (LAN), wide area network (WAN), and / or public networks, such as the Internet) via network adapter 20. Figure 3 As shown, network adapter 20 communicates with other modules of electronic device 12 via bus 18. It should be understood that, although... Figure 3 As not shown, other hardware and / or software modules may be used in conjunction with electronic device 12, including but not limited to: microcode, device drivers, redundant processing units, external disk drive arrays, RAID systems, tape drives, and data backup storage systems.

[0105] The processing unit 16 executes various functional applications and data processing by running programs stored in the system memory 28, such as implementing the lateral control test method for the electric power steering system provided in the embodiments of the present invention.

[0106] Example 4

[0107] Embodiment 4 of the present invention also provides a computer storage medium storing a computer program thereon, which, when executed by a processor, is used to implement the lateral control test method for the electric power steering system provided in the above embodiments.

[0108] The computer storage medium of this invention can be any combination of one or more computer-readable media. A computer-readable medium can be a computer-readable signal medium or a computer-readable storage medium. A computer-readable storage medium can be, for example,—but not limited to—an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any combination thereof. More specific examples of computer-readable storage media (a non-exhaustive list) include: an electrical connection having one or more wires, a portable computer disk, a hard disk, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fiber, portable compact disk read-only memory (CD-ROM), optical storage device, magnetic storage device, or any suitable combination thereof. In this document, a computer-readable storage medium can be any tangible medium that contains or stores a program that can be used by or in conjunction with an instruction execution system, apparatus, or device.

[0109] Computer-readable signal media may include data signals propagated in baseband or as part of a carrier wave, carrying computer-readable program code. Such propagated data signals may take various forms, including but not limited to electromagnetic signals, optical signals, or any suitable combination thereof. Computer-readable signal media may also be any computer-readable medium other than computer-readable storage media, capable of sending, propagating, or transmitting programs for use by or in connection with an instruction execution system, apparatus, or device.

[0110] Program code contained on a computer-readable medium may be transmitted using any suitable medium, including—but not limited to—wireless, wire, optical fiber, RF, etc., or any suitable combination thereof.

[0111] Computer program code for performing the operations of this invention can be written in one or more programming languages ​​or a combination thereof, including object-oriented programming languages ​​such as Java, Smalltalk, and C++, as well as conventional procedural programming languages ​​such as "C" or similar programming languages. The program code can be executed entirely on the user's computer, partially on the user's computer, as a standalone software package, partially on the user's computer and partially on a remote computer, or entirely on a remote computer or server. In cases involving remote computers, the remote computer can be connected to the user's computer via any type of network—including a local area network (LAN) or a wide area network (WAN)—or can be connected to an external computer (e.g., via the Internet using an Internet service provider).

[0112] Note that the above description is merely a preferred embodiment of the present invention and the technical principles employed. Those skilled in the art will understand that the present invention is not limited to the specific embodiments described herein, and various obvious changes, readjustments, and substitutions can be made without departing from the scope of protection of the present invention. Therefore, although the present invention has been described in detail through the above embodiments, the present invention is not limited to the above embodiments, and may include many other equivalent embodiments without departing from the concept of the present invention, the scope of which is determined by the scope of the appended claims.

Claims

1. A method for testing the lateral control of an electric power steering system, characterized in that, include: S101, respectively establish a trajectory tracking controller and a vehicle state observer, which together with the EPS system under test and the torque generator form an EPS lateral control test system; S102, the vehicle lateral state matrix is ​​calculated based on the vehicle dynamics model using the vehicle state observer, and the front wheel steering angle and rear wheel steering angle are calculated based on the deviation matrix between the vehicle lateral state matrix and the vehicle target trajectory using the trajectory tracking controller. The trajectory tracking controller is based on the vehicle lateral state matrix X and the vehicle target trajectory deviation matrix X. b Using the preset expected trajectory deviation matrix Q as X and X b The deviations between them are weighted, and the vehicle's front and rear wheel steering angle matrix Y is weighted using the preset trajectory control energy consumption matrix R, to construct a vehicle trajectory deviation function E containing the costate matrix P; Based on the principle of minimizing vehicle trajectory deviation in optimal control theory, the vehicle trajectory deviation function E is derived to form the front and rear wheel steering angle matrix Y. The co-state vector P is calculated based on the vehicle lateral state matrix X. The front and rear wheel steering angles are obtained by solving the front and rear wheel steering angle matrix Y based on the co-state vector P. S103, the vehicle state observer calculates the target steering angle, target speed and front wheel return resistance torque of the vehicle lateral control based on the front wheel steering angle and rear wheel steering angle. The torque generator generates simulated steering resistance based on the front wheel return resistance torque and applies it to the mechanical assembly of the EPS system under test. The vehicle state observer, based on the received front and rear wheel steering angles and Newton's laws and the force characteristics of the tires, calculates the front wheel lateral force, then calculates the front wheel return torque, and finally calculates the target steering angle θ based on the front wheel steering angle, the preset steering wheel angle, and the vehicle's gear ratio. * According to the target turning angle θ * Calculate the target rotational speed ω * ; S104, the EPS under test controls its mechanical assembly to perform steering assist control under the action of simulated steering resistance according to the target steering angle and target speed, so as to conduct dynamic testing of the EPS's lateral control function, response time and angle error.

2. The method according to claim 1, characterized in that: The vehicle lateral state matrix X includes lateral velocity v, yaw rate ω, lateral path offset y, and yaw angle φ; The vehicle target trajectory deviation matrix X b Including the expected lateral velocity deviation v b Expected yaw rate deviation ω b Expected lateral path offset deviation y b and the deviation of the expected yaw angle φ b .

3. The method according to claim 1, characterized in that: The vehicle dynamics model includes a lateral acceleration calculation model and a yaw rate calculation model. It can calculate lateral acceleration variables and yaw rate variables based on preset lateral vehicle speed, longitudinal vehicle speed, front and rear tire lateral stiffness, distance from the vehicle's center of mass to the center of the front wheel and the center of the rear wheel, vehicle weight, front and rear wheel steering angles, vehicle yaw rate, and vehicle yaw moment of inertia.

4. The method according to claim 3, characterized in that: The vehicle dynamics model also includes a lateral offset speed calculation model and a yaw angle error calculation model, which can calculate the lateral offset speed variable and the yaw angle error variable respectively based on preset lateral vehicle speed, longitudinal vehicle speed, vehicle yaw angle, vehicle yaw rate, and road curvature radius.

5. The method according to claim 4, characterized in that: The vehicle state observer calculates the vehicle lateral state matrix X by solving the first derivative equation based on the lateral acceleration calculation model, yaw angle acceleration calculation model, lateral offset velocity calculation model, and yaw angle error calculation model. The vehicle target trajectory deviation matrix X is calculated based on the preset vehicle coordinates, desired path coordinates, and desired path curvature radius. b .

6. A lateral control test system for an electric power steering system, used to implement the lateral control test method for the electric power steering system as described in any one of claims 1-5, characterized in that, include: The trajectory tracking control module is used to calculate the front wheel steering angle and rear wheel steering angle of the vehicle based on the vehicle lateral state matrix and the vehicle target trajectory deviation matrix. The vehicle state observation module is used to calculate the vehicle's lateral state matrix based on the vehicle dynamics model and form a closed-loop feedback with the trajectory tracking control module. It calculates the target steering angle, target speed, and front wheel positive resistance torque of the vehicle's lateral control based on the front wheel steering angle and rear wheel steering angle. A torque generator is used to generate simulated steering resistance based on the positive resistance torque of the front wheels, and then apply it to the mechanical assembly of the EPS system under test. The EPS module under test includes an electronic control unit connected to a vehicle status observation module and a mechanical assembly connected to a torque generator. The electronic control unit is configured to receive a target steering angle and a target speed, and control the mechanical assembly to perform steering assist control under the action of simulated steering resistance.

7. An electronic device, characterized in that, The system includes a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, it implements a lateral control test method for an electric power steering system as described in any one of claims 1-5.

8. A computer storage medium, characterized in that, It stores a computer program, which, when executed by a processor, implements the lateral control test method for the electric power steering system as described in any one of claims 1-5.

Images