Steer-by-wire testing method, device and equipment for vehicle entering and exiting curve and medium

Abstract

The embodiment of the invention provides a steer-by-wire test method, device and equipment for vehicle entering and exiting a curve and a medium, and belongs to the technical field of vehicle test. Comprising the steps that a vehicle basic model is obtained, a vehicle test model is built based on the vehicle basic model, and the vehicle test model is a vehicle parameterized model comprising a steer-by-wire system; constructing a test scene, wherein the test scene at least comprises a bend entering scene entering a ramp and a bend exiting scene leaving the ramp; based on the vehicle test model, virtual tests are executed in the bend-in scene and the bend-out scene respectively, the virtual tests are that a driver carries out simulated driving in the test scene, and objective test data and subjective evaluation of the driver are obtained; and determining objective evaluation according to the objective test data, and determining a test result of the steer-by-wire system according to the objective evaluation and the subjective evaluation. The invention aims to improve the testing accuracy of the steer-by-wire system so as to improve the design quality of the steer-by-wire system.

Description

Technical Field

[0001] The present invention relates to the field of vehicle testing technology, and in particular to a method, device, equipment and medium for testing vehicle steering-by-wire when entering or exiting a curve. Background Art

[0002] In existing technologies, steering systems are the primary system for controlling vehicles' emergency obstacle avoidance. With the development of intelligent driving technology, new demands on these systems have emerged and are attracting significant attention. Currently, steer-by-wire systems offer significant advantages in addressing challenges encountered in the development of intelligent driving, making them a popular choice for steering system technology. However, performance testing for steer-by-wire systems still relies on traditional steering system testing procedures, preventing effective testing of some steer-by-wire functions and impacting design quality.

[0003] In summary, the technical problems existing in the relevant technologies need to be improved. Summary of the Invention

[0004] The main purpose of the embodiments of the present application is to propose a method, device, equipment and medium for testing vehicle steering-by-wire when entering or exiting a curve, aiming to improve the accuracy of testing the steering-by-wire system and thus improve its design quality.

[0005] To achieve the above objectives, one aspect of an embodiment of the present application provides a method for testing vehicle steer-by-wire when entering or exiting a curve, comprising: Acquire a vehicle base model, and construct a vehicle test model based on the vehicle base model, wherein the vehicle test model is a parameterized model of the vehicle including a steer-by-wire system; Constructing a test scenario, wherein the test scenario includes at least a turning scene of entering a ramp and a turning scene of leaving a ramp; Based on the vehicle test model, performing virtual tests in the cornering scenario and the cornering exit scenario respectively, wherein the virtual tests involve a driver performing simulated driving in the test scenario to obtain objective test data and the driver's subjective evaluation; An objective evaluation is determined based on the objective test data, and a test result of the steer-by-wire system is determined based on the objective evaluation and the subjective evaluation.

[0006] In some embodiments, the step of determining an objective evaluation based on the objective test data includes: generating a first curve, a second curve, and a third curve based on the objective test data, wherein the first curve is a curve of lateral acceleration and steering wheel angle, the second curve is a curve of yaw rate and steering wheel angle, and the third curve is a curve of steering wheel torque and steering wheel angle; intercepting the first curve, the second curve, and the third curve according to a preset steering wheel angle range to obtain a first sub-curve, a second sub-curve, and a third sub-curve, respectively; The objective evaluation is determined according to the first sub-curve, the second sub-curve, and the third sub-curve.

[0007] In some embodiments, the step of determining the objective evaluation based on the first sub-curve, the second sub-curve, and the third sub-curve includes: performing a third-order polynomial fitting operation on the first sub-curve, the second sub-curve, and the third sub-curve, respectively, extracting a linear term coefficient of each fitting polynomial, and obtaining a first index corresponding to the lateral acceleration, a second index corresponding to the yaw angular velocity, and a third index corresponding to the steering wheel torque, respectively, the objective evaluation including the first index, the second index, and the third index; Linear fitting operations are performed on the first sub-curve, the second sub-curve, and the third sub-curve, respectively. A first linearity corresponding to the first sub-curve, a second linearity corresponding to the second sub-curve, and a third linearity corresponding to the third sub-curve are calculated based on the linear fitting results, respectively. The objective evaluation also includes the first linearity, the second linearity, and the third linearity.

[0008] In some embodiments, the subjective evaluation includes a working condition evaluation and a linearity evaluation, and the step of determining the test result of the steer-by-wire system based on the objective evaluation and the subjective evaluation includes: When the objective linearity reflected by the first linearity, the second linearity, and the third linearity is consistent with the linearity evaluation, an objective evaluation score is calculated based on the first indicator, the second indicator, the third indicator, the first linearity, the second linearity, and the third linearity, a subjective evaluation score is determined based on the operating condition evaluation, and the test result is determined based on the objective evaluation score and the subjective evaluation score.

[0009] In some embodiments, the step of constructing a vehicle test model based on the vehicle base model includes: Replacing the steering system in the vehicle base model with the steer-by-wire system, performing a co-simulation, and obtaining a co-simulation model when it is determined that the variable transmission ratio functions normally; The joint simulation model is downloaded to a real-time simulation system to obtain the vehicle test model.

[0010] In some embodiments, the step of constructing a test scenario includes: The cornering scenarios and the cornering exit scenarios with multiple different cornering radii are constructed respectively, and each of the test scenarios is set to a preset slope.

[0011] In some embodiments, after the step of respectively constructing the cornering scenarios and the cornering exit scenarios with a plurality of different cornering radii, the method further includes: A plurality of path points are respectively set in the cornering scene and the cornering exit scene, and each of the path points is set with a corresponding target speed, and the path points are used to guide the vehicle in the virtual test; and, The step of performing virtual testing in the cornering scenario and the cornering exit scenario respectively includes: In the cornering scenario and the cornering exit scenario, respectively, the vehicle is controlled to travel along the path points and according to the corresponding target speeds to perform the virtual test.

[0012] To achieve the above objectives, another aspect of the present application provides a vehicle steering-by-wire test device for entering and exiting a curve, the device comprising: a model processing module, configured to obtain a vehicle base model and construct a vehicle test model based on the vehicle base model, wherein the vehicle test model is a parameterized model of the vehicle including a steer-by-wire system; A scenario processing module, configured to construct a test scenario, wherein the test scenario includes at least a ramp entry scenario and a ramp exit scenario; a virtual testing module, configured to perform virtual testing in the cornering scenario and the cornering exit scenario based on the vehicle test model, wherein the virtual testing is a simulated driving by a driver in the test scenario to obtain objective test data and the driver's subjective evaluation; A test analysis module is configured to determine an objective evaluation based on the objective test data, and determine a test result of the steer-by-wire system based on the objective evaluation and the subjective evaluation.

[0013] To achieve the above-mentioned purpose, another aspect of an embodiment of the present application provides an electronic device, which includes a memory and a processor, wherein the memory stores a computer program, and the processor implements the above-mentioned method when executing the computer program.

[0014] To achieve the above objectives, another aspect of an embodiment of the present application provides a computer-readable storage medium, wherein the computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the method described above is implemented.

[0015] The embodiments of the present application include at least the following beneficial effects: The present application provides a method, apparatus, device, and medium for testing vehicle steer-by-wire when entering or exiting a curve. The solution obtains a basic vehicle model, constructs a vehicle test model including a steer-by-wire system based on the basic vehicle model, and constructs a test scenario for testing. Based on the vehicle test model, virtual tests are performed in the curve entry and curve exit scenarios in the test scenario, respectively, to obtain objective test data and the driver's subjective evaluation. An objective evaluation is determined based on the objective test data, and the test results of the steer-by-wire system are determined based on the objective evaluation and the subjective evaluation. Compared with the test process of the traditional steering system, the present application constructs a vehicle test model and test scenario specifically for testing the steer-by-wire system, and combines the objective evaluation of the objective test data and the subjective evaluation of the driver to determine the test results, thereby improving the accuracy of the steer-by-wire system test and thus improving its design quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 This is a flow chart of a method for testing vehicle steering-by-wire entering and exiting a curve provided by an embodiment of the present application; Figure 2 Schematic diagram of a cornering scenario and a cornering exit scenario according to an embodiment of the present application; Figure 3 is a schematic diagram of the first curve, the second curve and the third curve of the embodiment of the present application; Figure 4 This is a structural diagram of a vehicle steering-by-wire test device for entering and exiting a curve provided by an embodiment of the present application; Figure 5 This is a schematic diagram of the hardware structure of the electronic device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0017] In order to make the purpose, technical solutions and advantages of the present application clearer, the present application is further described in detail below with reference to the accompanying drawings and examples. It should be understood that the specific embodiments described herein are only used to explain the present application and are not intended to limit the present application. When the following description refers to the drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the embodiments of the present application. They are merely examples of devices and methods consistent with some aspects of the embodiments of the present application as detailed in the appended claims.

[0018] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which this application pertains. The terms used herein are for the purpose of describing the embodiments of this application only and are not intended to limit this application.

[0019] Among related technologies, the steering system, as the primary system for controlling a vehicle's emergency obstacle avoidance, has attracted significant attention with the development of intelligent driving technology, placing new demands on this system. Currently, steer-by-wire systems offer significant advantages in addressing challenges encountered in the development of intelligent driving, making them a common choice for steering system technology. However, performance testing for steer-by-wire systems still relies on traditional steering system testing procedures, preventing effective testing of some steer-by-wire functions and impacting design quality.

[0020] In view of this, embodiments of the present application provide a method, device, equipment, and medium for testing vehicle steering-by-wire when entering or exiting a curve. Figure 1 This is an optional flowchart of a vehicle steering-by-wire test method for entering and exiting a curve provided in an embodiment of the present application. Figure 1 The method may include but is not limited to steps S100 to S400.

[0021] Those skilled in the art will understand that the technical solutions shown in the figures do not constitute a limitation on the embodiments of the present application, and may include more or fewer steps than shown in the figures, or a combination of certain steps, or different steps.

[0022] Step S100: obtaining a vehicle basic model, and constructing a vehicle test model based on the vehicle basic model, wherein the vehicle test model is a parameterized model of the vehicle including a steer-by-wire system; During the vehicle development process, designers will use a vehicle parametric model. A vehicle parametric model is a mathematical or computer model that describes the vehicle's structure, performance, and dynamic characteristics through adjustable parameters. Its core concept is to decompose the vehicle's complex system into multiple quantifiable parameters. By adjusting these parameters, vehicle models with different configurations can be quickly generated for use in scenarios such as simulation, design optimization, or control algorithm development. This embodiment performs virtual testing of the steer-by-wire system based on the vehicle parametric model. The vehicle base model is used to define the default state of the vehicle parametric model, that is, the state where the steer-by-wire system is not configured. The vehicle test model is used to define the state where the steer-by-wire system is replaced, thereby distinguishing between the two states.

[0023] Steer-by-wire, on the other hand, is a steering technology that uses electronic signals rather than traditional mechanical links to achieve steering control. This technology eliminates the need for a physical steering column between the steering wheel and the wheels, instead transmitting steering commands electronically through communication between sensors, controllers, and actuators. Compared to traditional steering systems, this system offers advantages such as space savings, reduced wear on mechanical components, and adjustable steering feel, making it more suitable for the development of intelligent driving.

[0024] This application obtains a vehicle test model configured with a wire-steering system by replacing the traditional steering system of the default configuration of the vehicle test model with a wire-steering system, thereby supporting subsequent virtual testing of the wire-steering system.

[0025] In some embodiments, the step of constructing a vehicle test model based on the vehicle base model includes: The steering system in the basic vehicle model is replaced with a steer-by-wire system, and a co-simulation is performed. When it is determined that the variable transmission ratio functions normally, a co-simulation model is obtained; Download the joint simulation model to the real-time simulation system to obtain the vehicle test model.

[0026] Optionally, the steering system replacement can be performed through a vehicle simulation platform or software, such as CarRealTime or Adams / Car. Taking CarRealTime as an example, the basic vehicle model is imported into the software, and it is confirmed that the model file includes various subsystems of the vehicle, such as suspension, wheels, steering and power. For its steering system, it is replaced by a wire-controlled steering system. After the replacement, the model sends steering wheel angle and rack force signals to the wire-controlled steering system, and the wire-controlled steering system sends steering wheel torque and rack displacement signals to the model.

[0027] In order to verify whether the steering function is normal after replacing the wire-controlled steering system, a joint simulation is performed. Joint simulation is generally used to couple simulation models in multiple different fields through interfaces, and run them collaboratively in a unified simulation environment to simulate the overall behavior of a complex system. In this embodiment, it is to simulate the interactive operation between the wire-controlled steering system and the entire model. During the joint simulation process, it is monitored whether the wheel angles corresponding to the same steering wheel angles are consistent under different vehicle speed conditions. If they are consistent, it means that there is a problem with the replacement work and it needs to be repaired. If they are inconsistent, it means that the variable transmission ratio function is normal, that is, the steering function is normal. In other embodiments, it is also possible to determine whether there is a problem with the replacement work by verifying whether the torque feedback module and other special functions are normal. In this embodiment, the model after the joint simulation is defined as a joint simulation model.

[0028] Furthermore, the virtual test of the wire-controlled steering system is carried out through real-time simulation. Therefore, the joint simulation model is downloaded to the real-time simulation system through the Matlab compiler. After downloading to the real-time simulation system, the test conditions can be compiled first, and the relevant hardware functions can be checked to see whether they are normal, such as the force feedback motor, accelerator and brake pedals, and audio system, etc., so as to complete the relevant preparations for the model used in the test after confirming that there are no abnormal problems in all aspects, and define the vehicle test model of the model obtained at this time.

[0029] This embodiment uses joint simulation to check whether the variable transmission ratio function is normal, ensuring that the vehicle test model functions normally, thereby supporting the subsequent virtual test process and ensuring test accuracy.

[0030] Step S200: constructing a test scenario, where the test scenario includes at least a ramp entry scenario and a ramp exit scenario. Because virtual testing is performed through real-time simulation, which requires real-time interaction with the external physical world, it must respond to the driver's driving operations in real time, which is equivalent to simulated driving. Therefore, in addition to simulating driving using the vehicle test model, it is also necessary to prepare the road scenarios in which the vehicle will be driven.

[0031] It is understood that the steer-by-wire system is a function related to vehicle steering, so the test scenario is set to a curve scenario, specifically including at least the curve entry scenario of entering the ramp and the curve exit scenario of leaving the ramp, refer to Figure 2 , Figure 2 (a) shows the cornering scene. Figure 2 (b) shows a cornering scenario. In other embodiments, test scenarios such as continuous corners and U-shaped corners may also be included.

[0032] In some embodiments, the step of constructing a test scenario includes: Multiple cornering and exiting scenarios with different cornering radii were constructed, and each test scenario was set to a preset slope.

[0033] Optionally, the test scenario can be modeled and designed using software such as Prescan or RoadRunner, and a cornering scenario and a cornering exit scenario can be constructed separately. To ensure the diversity of test samples and improve test accuracy, multiple cornering scenarios and cornering exit scenarios are constructed according to different cornering radii. For example, cornering radii are set to include 30m, 50m, 70m, 90m, and 110m, and cornering scenarios and cornering exit scenarios corresponding to the five cornering radii are constructed, for a total of ten test scenarios. In other embodiments, cornering scenarios and cornering exit scenarios can also be constructed based on different combinations of cornering radii. For example, five cornering scenarios are constructed with cornering radii of 30m, 50m, 70m, 90m, and 110m, and five cornering scenarios are constructed with cornering radii of 40m, 60m, 80m, 100m, and 120m. The specific combination of cornering radii and the number of test scenarios can be determined based on the actual testing needs of the staff.

[0034] Furthermore, each test scenario needs to be set to a certain slope, defined in this embodiment as a preset slope, which can be set to, for example, 2% or 3%. Setting the test scenario to a certain slope can reduce reliance on tire friction and reproduce realistic road conditions, thereby further improving the accuracy of real-time simulation.

[0035] In other embodiments, the cornering and exiting scenarios may not be limited to a single corner. The cornering scenario may also be constructed to include a cornering portion and a pre-corner straight section, while the cornering scenario may also be constructed to include a cornering portion and a post-corner straight section. It will be understood that, referring to actual driving scenarios, cornering involves the vehicle decelerating from a straight line before entering the corner, while exiting a corner involves the vehicle gradually accelerating and straightening out of the corner after it has already been turning within the corner. Therefore, constructing the pre-corner straight section and post-corner straight section separately can help the vehicle's state before entering or after exiting the corner closely resemble that of a real cornering or exiting scenario, thereby improving the accuracy of virtual testing.

[0036] Step S300 , performing virtual tests in a cornering scenario and a cornering exit scenario based on the vehicle test model. The virtual test involves the driver performing simulated driving within the test scenario to obtain objective test data and the driver's subjective evaluation. After the vehicle test model and test scenario are prepared, virtual testing can be started for real-time simulation. Virtual testing requires the driver to simulate driving based on the vehicle test model in the constructed cornering and exiting scenarios. The test of the corresponding test scenario is not considered to be over until at least the vehicle passes the test starting point and test end point set in the scenario. If multiple cornering and exiting scenarios are constructed, each test scenario needs to be tested at least once.

[0037] During virtual testing, sensors installed on the vehicle test model collect data such as lateral acceleration and steering wheel angle. After pre-processing, such as data cleaning, the data generated for each test scenario is aggregated and analyzed in subsequent steps. This data is defined as objective test data. Meanwhile, subjective evaluations are collected from actual drivers participating in the simulated driving. These evaluations focus on vehicle linearity, steering force uniformity, and the degree to which the vehicle's cornering behavior matches the driver's expectations. Drivers provide a summary of these factors, providing a valuable reference for evaluating objective test data.

[0038] By collecting objective test data from virtual tests and the driver's subjective evaluation, the test results can be subsequently analyzed and determined from both subjective and objective dimensions, thereby improving the accuracy of the steer-by-wire system test.

[0039] In some embodiments, after the step of constructing a plurality of cornering scenarios and cornering exit scenarios with different cornering radii, the method further includes: Multiple path points are set in the cornering and exiting scenarios, and each path point is set with a corresponding target speed. The path points are used to guide the vehicle in the virtual test; and, The steps for performing virtual testing in both cornering and exiting scenarios include: In both cornering and exiting scenarios, the vehicle is controlled along the path points and at the corresponding target speeds for virtual testing.

[0040] Furthermore, in order to standardize the process of virtual testing, multiple path points can be set in the cornering and exiting scenes. The path points are set in the middle of the road to ensure that there is enough space for the vehicle to turn. Multiple path points are arranged along the extension direction of the road. Based on this, the curve formed by connecting all adjacent path points is actually equivalent to the target driving route of the test scene. Figure 2 , Figure 2 The path points are marked in the cornering and exiting scenes shown, and the serial numbers on them indicate the order in which the vehicle should pass. In addition, each path point is also set with its corresponding target speed, which represents the speed that the vehicle should have when passing through the path point. For example, a certain cornering scene has four path points, and their corresponding target speeds are 100km / h, 80km / h, 60km / h and 40km / h in order. Through the path points, test specifications are set in both the driving route and the speed. When conducting a virtual test, the driver needs to control the vehicle to drive along the path points and control the speed according to the target speed of the path points, so that the entire driving process of the test has a clear standard process, which is convenient for comparing differences when analyzing data and improving the effect of virtual testing.

[0041] Step S400 : determining an objective evaluation based on the objective test data, and determining a test result of the steer-by-wire system based on the objective evaluation and the subjective evaluation.

[0042] Objective test data also needs to be analyzed and summarized to generate objective evaluations relative to the driver's subjective assessments. By analyzing the objective test data, several parameters representing the objective evaluations are obtained. These parameters are then converted into intuitive evaluation scores. Finally, the subjective evaluations are combined with the objective evaluations, using the objective evaluations as the benchmark and the subjective evaluations as the veto factor representing human opinion. The final test results are determined by combining these two dimensions of evaluation: objective and subjective.

[0043] It should be noted that the content of objective evaluation is not consistent with that of subjective evaluation. For example, objective evaluation does not include three types of data: A1, B1 and C1, and subjective evaluation also includes three types of data: A2, B2 and C2. This is because subjective evaluation is based on the driver's driving experience and cannot be subdivided into multiple dimensions of data like objective test data.

[0044] In some embodiments, the step of determining an objective assessment based on the objective test data includes: generating a first curve, a second curve, and a third curve based on the objective test data, wherein the first curve is a curve of lateral acceleration and steering wheel angle, the second curve is a curve of yaw rate and steering wheel angle, and the third curve is a curve of steering wheel torque and steering wheel angle; Intercepting the first curve, the second curve, and the third curve according to a preset steering wheel angle range to obtain a first sub-curve, a second sub-curve, and a third sub-curve, respectively; An objective evaluation is determined based on the first sub-curve, the second sub-curve, and the third sub-curve.

[0045] Specifically, during the virtual test, the data collected by the sensors include at least lateral acceleration, yaw angular velocity, steering wheel torque, and steering wheel angle. The lateral acceleration is the acceleration of the vehicle perpendicular to the direction of travel (i.e., the lateral direction) during driving. It is usually caused by centrifugal force during steering and can reflect the lateral stability of the vehicle during steering. The greater the lateral acceleration, the higher the risk of vehicle roll. The yaw rate is the angular velocity of the vehicle about the vertical axis. It can describe the speed and direction of the vehicle's rotation during steering. The yaw rate reflects the vehicle's steering response speed. In practical applications, it is also closely related to systems such as lane keeping and obstacle avoidance, affecting whether the vehicle deviates from the intended driving path. The steering wheel torque is the rotational torque applied by the driver to the steering wheel to overcome the resistance of the steer-by-wire system. The steering wheel torque affects driving feel and the design of the steering power system. If the steering wheel torque is too large, it will increase driver fatigue during steering. If it is too small, it may cause the driver to lose road feel and affect driving accuracy. The steering wheel angle is the rotation angle of the steering wheel relative to its neutral position (the vehicle is driving straight ahead) and is a fundamental parameter of the vehicle's steering geometry. Within the maximum tire steering angle limit, the larger the steering wheel angle, the larger the front wheel steering angle and the smaller the turning radius. It is one of the input variables for vehicle steering.

[0046] For the four parameters of lateral acceleration, yaw rate, steering wheel torque and steering wheel angle, the first curve of lateral acceleration and steering wheel angle, the second curve of yaw rate and steering wheel angle, and the third curve of steering wheel torque and steering wheel angle are generated respectively. Figure 3 , Figure 3 The curves (a), (b), and (c) shown are the first, second, and third curves, respectively. It should be noted that the steering wheel angle is converted to a percentage of the maximum rotatable angle for analysis, rather than using the angle data directly.

[0047] In this embodiment, the analysis is mainly performed on the portion of the curve where the linearity is more obvious. Therefore, the curve needs to be intercepted. Using a preset steering wheel angle range, for example, 30% to 70%, the portions of the first curve, the second curve, and the third curve that fall within the preset steering wheel angle range are intercepted. Figure 3The preset steering wheel angle range is also illustrated. It should also be noted that different preset steering wheel angle ranges can be used for interception of the first, second, and third curves. For example, the first curve intercepts 20% to 55%, the second curve intercepts 30% to 60%, and the third curve intercepts 25% to 70%. Staff can customize the preset steering wheel angle range for each curve, i.e., a customized interception range, by observing the curves or based on actual test requirements. The intercepted curve segments are defined as the first, second, and third sub-curves, respectively, and the objective evaluation is further determined based on the first, second, and third sub-curves.

[0048] By intercepting the portions of the first, second, and third curves that fall within the preset steering wheel angle range, the first, second, and third sub-curves with higher linear components are extracted for analysis. This allows subsequent data analysis to better reflect the performance of the steer-by-wire system and improves the accuracy of objective evaluation.

[0049] In some embodiments, the step of determining the objective evaluation based on the first sub-curve, the second sub-curve, and the third sub-curve includes: Performing a third-order polynomial fitting operation on the first sub-curve, the second sub-curve, and the third sub-curve, extracting the linear coefficient of each fitting polynomial, and obtaining a first index corresponding to the lateral acceleration, a second index corresponding to the yaw rate, and a third index corresponding to the steering wheel torque, respectively. The objective evaluation includes the first index, the second index, and the third index. Linear fitting operations are performed on the first sub-curve, the second sub-curve, and the third sub-curve, respectively. A first linearity corresponding to the first sub-curve, a second linearity corresponding to the second sub-curve, and a third linearity corresponding to the third sub-curve are calculated based on the linear fitting results. The objective evaluation also includes the first linearity, the second linearity, and the third linearity.

[0050] Furthermore, a third-order polynomial fitting operation is performed on the first, second, and third subcurves, respectively, to obtain a polynomial representing the corresponding subcurve, consisting of a cubic term, a quadratic term, a linear term, and a zero-order term. The coefficients of the linear terms in these polynomials are then extracted. For the first subcurve, the corresponding linear coefficient is defined as the first indicator, equivalent to an indicator related to lateral acceleration, representing the slope of the lateral acceleration response versus the steering wheel angle in the linear region, and characterizing the vehicle's dynamic response. For the second subcurve, the corresponding linear coefficient is defined as the second indicator, equivalent to an indicator related to yaw rate, representing the slope of the yaw rate versus the steering wheel angle in the linear region, and characterizing the vehicle's yaw response, i.e., the vehicle's stability. For the third subcurve, the corresponding linear coefficient is defined as the third indicator, equivalent to an indicator related to steering wheel torque, representing the slope of the steering wheel torque versus the steering wheel angle in the linear region, and characterizing the gain in driver hand force. Furthermore, the first, second, and third indicators, depending on their meanings, can also be defined as comprehensive steering sensitivity, comprehensive vehicle stability coefficient, and comprehensive steering stiffness, respectively.

[0051] On the other hand, the linearity of the three sub-curves needs to be calculated. Linearity is an indicator that measures the degree of deviation from the linear relationship between output and input, and can also be expressed as nonlinear error. Specifically, linear fitting operations are performed on the first sub-curve, the second sub-curve, and the third sub-curve. The ideal straight line obtained by linear fitting is compared with the corresponding sub-curve, and the corresponding linearity of the three sub-curves is calculated using the following formula (1): (1) in, is the linearity, is the actual value of the curve, is the ideal value of the ideal straight line, is the average value of the actual value. The first linearity of the first sub-curve, the second linearity of the second sub-curve, and the third linearity of the third sub-curve can be calculated respectively by formula (1). The first linearity and the second linearity are equivalent to the gain linearity reflecting the change of vehicle dynamic response with the steering wheel angle, and the third linearity is equivalent to the gain linearity reflecting the change of steering wheel torque with the steering wheel angle.

[0052] The first index, first linearity, second index, second linearity, third index, and third linearity obtained in the above steps are all objective evaluations. By calculating these various objective evaluations, the objective evaluations incorporate characteristics such as vehicle dynamic response and yaw response, thereby improving the accuracy of the objective evaluations.

[0053] In some embodiments, the subjective evaluation includes a working condition evaluation and a linearity evaluation, and the step of determining the test result of the steer-by-wire system based on the objective evaluation and the subjective evaluation includes: When the objective linearity reflected by the first linearity, the second linearity and the third linearity is consistent with the linearity evaluation, the objective evaluation score is calculated based on the first indicator, the second indicator, the third indicator, the first linearity, the second linearity and the third linearity, the subjective evaluation score is determined based on the working condition evaluation, and the test result is determined based on the objective evaluation score and the subjective evaluation score.

[0054] Optionally, the subjective evaluation includes a working condition evaluation and a linearity evaluation. The working condition evaluation assesses the vehicle's overall working condition during the virtual test, expressed as a working condition score. The working condition score can be set to a decimal system, with a score interval of 0.25, such as 8 representing very good and 7 representing excellent. It can also be set to a 100-base system. The linearity evaluation assesses the driver's subjective driving experience of the vehicle's linearity, and can also be set to a score or grade. It should be noted that the working condition evaluation can include a score for linearity, and the separate linearity evaluation is provided for comparison with the objective evaluation.

[0055] In objective evaluation, the first, second, and third linearity measures each reflect the degree to which the proportional relationship between output and input in a certain direction conforms to a linear law. Linearity is also the foundation of the linearity of the driving experience. While high linearity does not necessarily mean good linearity, poor linearity definitely indicates poor linearity. Based on this, the objective linearity reflected by the first, second, and third linearity measures is determined through mapping. The objective linearity is then compared with the linearity evaluation to determine whether it is consistent. If not, typically indicating high linearity but poor linearity, the subjective evaluation is considered a veto, the test result is deemed unsatisfactory, and subsequent analysis steps can be skipped. If consistent, the specific test score is further calculated. Specifically, the objective evaluation score is obtained through a weighted calculation based on the six parameters: the first indicator, the second indicator, the third indicator, the first linearity, the second linearity, and the third linearity, as well as the preset weights corresponding to each parameter. It should be noted that the first indicator, the second indicator, the third indicator, the first linearity, the second linearity, and the third linearity must be converted to the same scale before weighting.

[0056] On the other hand, although the operating condition evaluation is also expressed in the form of a score, its scoring scale may not be consistent with the objective evaluation score. Therefore, the operating condition score can be converted to the same scale as the objective evaluation score, defined as a subjective evaluation score. Finally, the final test score is determined by weighting the subjective evaluation score with the objective evaluation score. The subjective evaluation score can be given a higher weight, with the driver's subjective experience as the most important reference factor. The test score can then be used to determine whether the test has passed, for example, a score of 60 or above passes the test. In addition, the test score can also serve as a performance reference score for the currently designed steer-by-wire system.

[0057] By first comparing linearity and linear feel, and then determining the test results by calculating objective and subjective evaluation scores, the linear feel experience can be used as a test rejection item, and the final test results can be obtained by combining references from both subjective and objective dimensions, thereby improving the accuracy of the steer-by-wire system test.

[0058] In steps S100 to S400 illustrated in the embodiment of the present application, a vehicle test model including a steer-by-wire system is constructed based on the vehicle base model by acquiring a vehicle base model, and a test scenario is constructed for testing. Based on the vehicle test model, virtual tests are performed in the cornering and cornering scenarios of the test scenario, respectively, to obtain objective test data and the driver's subjective evaluation. An objective evaluation is determined based on the objective test data, and the test results of the steer-by-wire system are determined based on the objective evaluation and the subjective evaluation. Compared with the test process of the traditional steering system, the present application constructs a vehicle test model and test scenario specifically for testing the steer-by-wire system, and combines the objective evaluation of the objective test data and the subjective evaluation of the driver to determine the test results, thereby improving the accuracy of the steer-by-wire system test and thus improving its design quality.

[0059] The following describes the embodiments of the present invention in detail with reference to specific application examples: In an embodiment of the present application, a method for testing vehicle steer-by-wire when entering or exiting a curve is provided. The method obtains a basic vehicle model, replaces the steering system in the basic vehicle model with a steer-by-wire system, and performs a joint simulation. When it is determined that the variable transmission ratio function is normal, a joint simulation model is obtained, and the joint simulation model is downloaded to a real-time simulation system to obtain a vehicle test model.

[0060] Multiple cornering and exiting scenarios with different cornering radii are constructed, and each test scenario is set to a preset slope. Multiple path points are set in the cornering and exiting scenarios, and each path point is set with a corresponding target speed to guide vehicle driving in subsequent virtual tests.

[0061] Based on the vehicle test model, virtual testing is performed by controlling the vehicle along the path points and according to the corresponding target speed in both cornering and exiting scenarios to obtain objective test data and the driver's subjective evaluation, which includes operating condition evaluation and linearity evaluation.

[0062] A first curve of lateral acceleration and steering wheel angle, a second curve of yaw angular velocity and steering wheel angle, and a third curve of steering wheel torque and steering wheel angle are generated based on objective test data. The first, second, and third curves are intercepted according to a preset steering wheel angle range to obtain a first sub-curve, a second sub-curve, and a third sub-curve, respectively.

[0063] A third-order polynomial fitting operation is performed on the first sub-curve, the second sub-curve, and the third sub-curve, respectively. The linear coefficient of each fitting polynomial is extracted to obtain a first index corresponding to the lateral acceleration, a second index corresponding to the yaw angular velocity, and a third index corresponding to the steering wheel torque, respectively. A linear fitting operation is performed on the first sub-curve, the second sub-curve, and the third sub-curve, respectively. The first linearity, the second linearity, and the third linearity are calculated based on the linear fitting results.

[0064] When the objective linearity reflected by the first linearity, the second linearity, and the third linearity is consistent with the linearity evaluation, the objective evaluation score is calculated based on the first indicator, the second indicator, the third indicator, the first linearity, the second linearity, and the third linearity, the subjective evaluation score is determined based on the working condition evaluation, and then the test result is determined based on the objective evaluation score and the subjective evaluation score.

[0065] refer to Figure 4 The present application also provides a device for testing vehicle steering-by-wire when entering or exiting a curve, which can implement the above-mentioned method for testing vehicle steering-by-wire when entering or exiting a curve. The device includes: A model processing module is used to obtain a vehicle basic model and construct a vehicle test model based on the vehicle basic model, where the vehicle test model is a parameterized model of the vehicle including a steer-by-wire system; A scenario processing module is used to construct a test scenario, which includes at least a ramp entry scenario and a ramp exit scenario; A virtual testing module is used to perform virtual testing in both cornering and exiting scenarios based on the vehicle test model. The virtual testing simulates driving within the test scenario to obtain objective test data and the driver's subjective evaluation. The test analysis module is used to determine an objective evaluation based on the objective test data, and to determine a test result of the steer-by-wire system based on the objective evaluation and the subjective evaluation.

[0066] It can be understood that the contents of the above method embodiments are all applicable to the present device embodiments, the functions specifically implemented by the present device embodiments are the same as those of the above method embodiments, and the beneficial effects achieved are also the same as those achieved by the above method embodiments.

[0067] The present application also provides an electronic device comprising a memory and a processor. The memory stores a computer program, and the processor executes the computer program to implement the aforementioned vehicle steer-by-wire test method for entering and exiting a curve. The electronic device can be any smart terminal, including a tablet computer and an in-vehicle computer.

[0068] It can be understood that the contents of the above method embodiments are applicable to the present device embodiments, the functions specifically implemented by the present device embodiments are the same as those of the above method embodiments, and the beneficial effects achieved are also the same as those achieved by the above method embodiments.

[0069] refer to Figure 5 , Figure 5 The hardware structure of an electronic device according to another embodiment is shown. The electronic device includes: The processor 901 can be implemented as a general-purpose CPU (Central Processing Unit), a microprocessor, an application-specific integrated circuit (ASIC), or one or more integrated circuits, and is used to execute relevant programs to implement the technical solutions provided in the embodiments of the present application; The memory 902 can be implemented in the form of a read-only memory (ROM), a static storage device, a dynamic storage device, or a random access memory (RAM). The memory 902 can store an operating system and other application programs. When the technical solutions provided in the embodiments of this specification are implemented through software or firmware, the relevant program code is stored in the memory 902 and is called by the processor 901 to execute the vehicle steering-by-wire test method for entering and exiting a curve in the embodiments of this application. Input / output interface 903, used to implement information input and output; Communication interface 904, used to implement communication interaction between this device and other devices, which can be achieved through wired means (such as USB, network cable, etc.) or wireless means (such as mobile network, WiFi, Bluetooth, etc.); Bus 905 , which transmits information between various components of the device (e.g., processor 901 , memory 902 , input / output interface 903 , and communication interface 904 ); The processor 901 , the memory 902 , the input / output interface 903 and the communication interface 904 are connected to each other in communication within the device via a bus 905 .

[0070] An embodiment of the present application also provides a computer-readable storage medium, which stores a computer program. When the computer program is executed by a processor, it implements the above-mentioned vehicle steering-by-wire test method for entering and exiting a curve.

[0071] It can be understood that the contents of the above method embodiments are all applicable to the present storage medium embodiment, the functions specifically implemented by the present storage medium embodiment are the same as those of the above method embodiments, and the beneficial effects achieved are also the same as those achieved by the above method embodiments.

[0072] The memory, as a non-transient computer-readable storage medium, can be used to store non-transient software programs and non-transient computer executable programs. In addition, the memory may include a high-speed random access memory and may also include a non-transient memory, such as at least one disk storage device, a flash memory device, or other non-transient solid-state storage device. In some embodiments, the memory may optionally include a memory remotely arranged relative to the processor, and these remote memories may be connected to the processor via a network. Examples of the above-mentioned network include, but are not limited to, the Internet, an intranet, a local area network, a mobile communication network, and combinations thereof.

[0073] The embodiments described in the embodiments of this application are intended to more clearly illustrate the technical solutions of the embodiments of this application and do not constitute a limitation on the technical solutions provided by the embodiments of this application. Those skilled in the art will appreciate that with the evolution of technology and the emergence of new application scenarios, the technical solutions provided in the embodiments of this application are also applicable to similar technical problems.

[0074] Those skilled in the art will appreciate that all or some of the steps in the methods, systems, and functional modules / units in the devices disclosed above may be implemented as software, firmware, hardware, or appropriate combinations thereof.

[0075] The terms "first", "second", "third", "fourth", etc. (if any) in the specification of the present application and the above-mentioned drawings are used to distinguish similar objects and are not necessarily used to describe a specific order or sequential order. It should be understood that the data used in this way can be interchangeable where appropriate, so that the embodiments of the present application described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0076] It should be understood that in this application, "at least one (item)" means one or more, and "plurality" means two or more. "And / or" is used to describe the association relationship of associated objects, indicating that three relationships may exist. For example, "A and / or B" can mean: only A exists, only B exists, and A and B exist at the same time, where A and B can be singular or plural. The character " / " generally indicates that the previous and next associated objects are in an "or" relationship. "At least one of the following items" or similar expressions refers to any combination of these items, including any combination of single items or plural items. For example, at least one of a, b or c can mean: a, b, c, "a and b", "a and c", "b and c", or "a and b and c", where a, b, c can be single or multiple.

[0077] In the several embodiments provided in this application, it should be understood that the disclosed devices and methods can be implemented in other ways. For example, the device embodiments described above are merely schematic. For example, the division of the above-mentioned units is only a logical function division. In actual implementation, there may be other division methods, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms.

[0078] The units described above as separate components may or may not be physically separate, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed across multiple network units. Some or all of these units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0079] In addition, the functional units in the various embodiments of the present application may be integrated into a single processing unit, or each unit may exist physically separately, or two or more units may be integrated into a single unit. The aforementioned integrated units may be implemented in the form of hardware or software functional units.

[0080] If the integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present application, 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, which is stored in a storage medium and includes multiple instructions for enabling a computer device (which can be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods of various embodiments of the present application. The aforementioned storage medium includes: various media that can store programs, such as a USB flash drive, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk.

[0081] The preferred embodiments of the present invention are described above with reference to the accompanying drawings, but are not intended to limit the scope of the present invention. Any modifications, equivalent substitutions, and improvements made by those skilled in the art without departing from the scope and essence of the present invention should be within the scope of the present invention.

Claims

1. A method for testing vehicle steering-by-wire when entering or exiting a curve, characterized in that: The method comprises: Acquire a vehicle base model, and construct a vehicle test model based on the vehicle base model, wherein the vehicle test model is a parameterized model of the vehicle including a steer-by-wire system; Constructing a test scenario, wherein the test scenario includes at least a turning scene of entering a ramp and a turning scene of leaving a ramp; Based on the vehicle test model, performing virtual tests in the cornering scenario and the cornering exit scenario respectively, wherein the virtual tests involve a driver performing simulated driving in the test scenario to obtain objective test data and the driver's subjective evaluation; An objective evaluation is determined based on the objective test data, and a test result of the steer-by-wire system is determined based on the objective evaluation and the subjective evaluation.

2. The method according to claim 1, characterized in that The step of determining the objective evaluation based on the objective test data comprises: generating a first curve, a second curve, and a third curve based on the objective test data, wherein the first curve is a curve of lateral acceleration and steering wheel angle, the second curve is a curve of yaw rate and steering wheel angle, and the third curve is a curve of steering wheel torque and steering wheel angle; intercepting the first curve, the second curve, and the third curve according to a preset steering wheel angle range to obtain a first sub-curve, a second sub-curve, and a third sub-curve, respectively; The objective evaluation is determined according to the first sub-curve, the second sub-curve, and the third sub-curve.

3. The method according to claim 2, characterized in that The step of determining the objective evaluation according to the first sub-curve, the second sub-curve, and the third sub-curve comprises: performing a third-order polynomial fitting operation on the first sub-curve, the second sub-curve, and the third sub-curve, respectively, extracting a linear term coefficient of each fitting polynomial, and obtaining a first index corresponding to the lateral acceleration, a second index corresponding to the yaw angular velocity, and a third index corresponding to the steering wheel torque, respectively, the objective evaluation including the first index, the second index, and the third index; Linear fitting operations are performed on the first sub-curve, the second sub-curve, and the third sub-curve, respectively. A first linearity corresponding to the first sub-curve, a second linearity corresponding to the second sub-curve, and a third linearity corresponding to the third sub-curve are calculated based on the linear fitting results, respectively. The objective evaluation also includes the first linearity, the second linearity, and the third linearity.

4. The method according to claim 3, characterized in that The subjective evaluation includes a working condition evaluation and a linearity evaluation. The step of determining the test result of the steer-by-wire system based on the objective evaluation and the subjective evaluation includes: When the objective linearity reflected by the first linearity, the second linearity, and the third linearity is consistent with the linearity evaluation, an objective evaluation score is calculated based on the first indicator, the second indicator, the third indicator, the first linearity, the second linearity, and the third linearity, a subjective evaluation score is determined based on the operating condition evaluation, and the test result is determined based on the objective evaluation score and the subjective evaluation score.

5. The method according to claim 1, wherein The step of constructing a vehicle test model based on the vehicle basic model includes: Replacing the steering system in the vehicle base model with the steer-by-wire system, performing a co-simulation, and obtaining a co-simulation model when it is determined that the variable transmission ratio functions normally; The joint simulation model is downloaded to a real-time simulation system to obtain the vehicle test model.

6. The method according to claim 1, wherein The steps of constructing the test scenario include: The cornering scenarios and the cornering exit scenarios with multiple different cornering radii are constructed respectively, and each of the test scenarios is set to a preset slope.

7. The method according to claim 6, characterized in that After the step of respectively constructing the cornering scenarios and the cornering exit scenarios with a plurality of different cornering radii, the method further includes: A plurality of path points are respectively set in the cornering scene and the cornering exit scene, and each of the path points is set with a corresponding target speed, and the path points are used to guide the vehicle in the virtual test; and, The step of performing virtual testing in the cornering scenario and the cornering exit scenario respectively includes: In the cornering scenario and the cornering exit scenario, respectively, the vehicle is controlled to travel along the path points and according to the corresponding target speeds to perform the virtual test.

8. A vehicle steering-by-wire test device for entering and exiting a curve, characterized in that: The device comprises: a model processing module, configured to obtain a vehicle base model and construct a vehicle test model based on the vehicle base model, wherein the vehicle test model is a parameterized vehicle model including a steer-by-wire system; A scenario processing module, configured to construct a test scenario, wherein the test scenario includes at least a ramp entry scenario and a ramp exit scenario; a virtual testing module, configured to perform virtual testing in the cornering scenario and the cornering exit scenario based on the vehicle test model, wherein the virtual testing is a simulated driving by a driver in the test scenario to obtain objective test data and the driver's subjective evaluation; A test analysis module is configured to determine an objective evaluation based on the objective test data, and determine a test result of the steer-by-wire system based on the objective evaluation and the subjective evaluation.

9. An electronic device, characterized in that: The electronic device includes a memory and a processor, the memory stores a computer program, and the processor implements the method according to any one of claims 1 to 7 when executing the computer program.

10. A computer-readable storage medium storing a computer program, characterized in that: When the computer program is executed by a processor, the method according to any one of claims 1 to 7 is implemented.

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