Test method and product for steer-by-wire variable transmission ratio strategy

Abstract

The invention provides a steering-by-wire variable transmission ratio strategy test method and product, and the test method comprises the steps: obtaining a vehicle dynamics model which has a steering-by-wire variable transmission ratio strategy; acquiring a motion scene used for testing the steer-by-wire variable transmission ratio strategy; based on the vehicle dynamics model and the motion scene, the steer-by-wire variable transmission ratio strategy is tested, and a test result is obtained; and when the test result is unqualified, the steer-by-wire variable transmission ratio strategy is adjusted. According to the method and the product for testing the steer-by-wire variable transmission ratio strategy provided by the invention, the steer-by-wire variable transmission ratio strategy can be comprehensively and effectively tested based on the vehicle dynamics model with the steer-by-wire variable transmission ratio strategy and the motion scene for testing the steer-by-wire variable transmission ratio strategy; the defects of steer-by-wire variable transmission ratio strategy test verification in the field of steer-by-wire are overcome.

Description

Technical Field

[0001] The present invention relates to the technical field of vehicle steer-by-wire technology, and in particular to a test method and product for a steer-by-wire variable transmission ratio strategy. Background Art

[0002] With the development of vehicle steer-by-wire technology, traditional mechanical steering is increasingly unable to meet the needs of smart vehicles. Steer-by-wire is different from mechanical steering in that it eliminates the physical transmission of the intermediate column and has the advantages of a large variable transmission ratio design range and sufficient operating space, and is gradually entering the public eye.

[0003] Since the variable transmission ratio of steer-by-wire changes not only with the change of steering wheel angle, but also with the change of vehicle speed, in the larger variable transmission ratio design space, it is necessary to test the steer-by-wire variable transmission ratio strategy during the development process of the steer-by-wire variable transmission ratio strategy, so as to discover problems in the early stage of the development of the steer-by-wire variable transmission ratio strategy and continuously optimize the steer-by-wire variable transmission ratio strategy.

[0004] How to conduct comprehensive and effective testing on the variable transmission ratio strategy of steer-by-wire and fill the gap in the testing and verification of variable transmission ratio strategies in the field of steer-by-wire technology has become an urgent problem to be solved. Summary of the invention

[0005] The present application provides a method for testing a steer-by-wire variable transmission ratio strategy, comprising: obtaining a vehicle dynamics model, wherein the vehicle dynamics model has a steer-by-wire variable transmission ratio strategy; obtaining a motion scene for testing the steer-by-wire variable transmission ratio strategy; testing the steer-by-wire variable transmission ratio strategy based on the vehicle dynamics model and the motion scene to obtain a test result; and adjusting the steer-by-wire variable transmission ratio strategy when the test result is unqualified.

[0006] In one embodiment, the motion scenario includes a steering motion scenario and a lane changing motion scenario; the testing of the variable transmission ratio strategy of the steer-by-wire control based on the vehicle dynamics model and the motion scenario includes: performing a steering sensitivity test on the vehicle based on the vehicle dynamics model and the steering motion scenario to obtain a steering sensitivity test result of the vehicle; performing a corner limit position test on the vehicle based on the vehicle dynamics model and the steering motion scenario to obtain a corner limit position test result of the vehicle; performing a low speed threshold test on the vehicle based on the vehicle dynamics model and the lane changing motion scenario to obtain a low speed threshold test result of the vehicle; wherein the test results include a steering sensitivity test result, a corner limit position test result and a low speed threshold test result of the vehicle.

[0007] In one embodiment, the steering sensitivity test of the vehicle is performed based on the vehicle dynamics model and the steering motion scenario to obtain the steering sensitivity test result of the vehicle, including: based on the vehicle dynamics model, controlling the vehicle to perform a steering motion in the steering motion scenario at a first speed; determining the steering sensitivity test result of the vehicle at the first speed according to a first operating condition parameter and / or a first driving score during the vehicle performing the steering motion; wherein the first operating condition parameter includes a steering wheel angle of the vehicle, and at least one of the lateral acceleration, yaw angular velocity and rack displacement of a steering rod of the vehicle.

[0008] In one embodiment, determining a steering sensitivity test result of the vehicle at a first speed according to a first operating condition parameter in the steering motion performed by the vehicle includes: determining a steering wheel angle-lateral acceleration curve of the vehicle at the first speed according to a steering wheel angle of the vehicle and a lateral acceleration of the vehicle; and / or determining a steering wheel angle-yaw velocity curve of the vehicle at the first speed according to a steering wheel angle of the vehicle and a yaw velocity of the vehicle; and / or determining a steering wheel angle-steering rod rack displacement curve of the vehicle at the first speed according to a steering wheel angle of the vehicle and a rack displacement of a steering rod of the vehicle; determining a steering sensitivity test result of the vehicle at the first speed according to a slope of at least one of a steering wheel angle-lateral acceleration curve, a steering wheel angle-yaw velocity curve, and a steering wheel angle-steering rod rack displacement curve of the vehicle at the first speed at a steering wheel angle of 0.

[0009] In one embodiment, the vehicle is subjected to a corner limit position test based on the vehicle dynamics model and the steering motion scenario to obtain a corner limit position test result of the vehicle, including: based on the vehicle dynamics model, controlling the vehicle to drive in a straight line at a second speed in the steering motion scenario for a preset time period, and then continuing to control the vehicle to perform a U-turn motion at a third speed in the steering motion scenario; determining a corner limit position test result of the vehicle at the third speed according to a second operating condition parameter and a second driving score during the vehicle's execution of the U-turn motion; wherein the second operating condition parameter includes a steering wheel angle and a yaw angular velocity of the vehicle.

[0010] In one embodiment, determining the corner limit position test result of the vehicle at the third speed based on the second operating condition parameter and the second driving score during the vehicle's execution of the U-turn movement includes: determining the steering wheel angle-yaw rate curve of the vehicle at the third speed based on the steering wheel angle and yaw rate curve of the vehicle; determining the limit steering wheel angle of the vehicle at the third speed based on the steering wheel angle-yaw rate curve of the vehicle at the third speed; determining the corner limit position test result of the vehicle at the third speed based on the limit steering wheel angle and the second driving score.

[0011] In one embodiment, the low-speed threshold test is performed on the vehicle based on the vehicle dynamics model and the lane changing motion scenario to obtain the low-speed threshold test result of the vehicle, including: based on the vehicle dynamics model, controlling the vehicle to perform lane changing motion at a fourth speed in the lane changing motion scenario; determining the low-speed threshold test result of the vehicle according to a third operating condition parameter and / or a third driving score during the lane changing motion of the vehicle; wherein the difference between the fourth speed and the low-speed threshold of the vehicle is within a preset range, and the low-speed threshold of the vehicle is determined based on the variable transmission ratio strategy of the steer-by-wire control; and the third operating condition parameter includes the movement duration and driving distance of the vehicle.

[0012] In one embodiment, a low-speed threshold test result of the vehicle is determined based on a third operating condition parameter of the vehicle during the lane changing motion, including: judging whether the low-speed threshold of the vehicle meets driving requirements based on the movement duration and driving distance of the vehicle during the lane changing motion; if the low-speed threshold of the vehicle meets the driving requirements, the low-speed threshold test of the vehicle is qualified; if the low-speed threshold of the vehicle does not meet the driving requirements, the low-speed threshold test of the vehicle is unqualified.

[0013] In one embodiment, the obtaining of the vehicle dynamics model includes: obtaining a suspension model, a body model, a tire model, an engine model and a steer-by-wire system model; wherein the steer-by-wire system model has the steer-by-wire variable transmission ratio strategy; and determining the vehicle dynamics model based on the suspension model, the body model, the tire model, the power model and the steer-by-wire system model.

[0014] The present application also provides a testing system for a variable transmission ratio strategy of steer-by-wire, comprising a first acquisition module, a second acquisition module and a testing module; the first acquisition module is used to acquire a vehicle dynamics model, the vehicle dynamics model having a variable transmission ratio strategy of steer-by-wire; the second acquisition module is used to acquire a motion scene for testing the variable transmission ratio strategy of steer-by-wire; the testing module is used to test the variable transmission ratio strategy of steer-by-wire based on the vehicle dynamics model and the motion scene, obtain a test result, and adjust the variable transmission ratio strategy of steer-by-wire when the test result is unqualified.

[0015] The present application also 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 test method for the variable transmission ratio strategy of wire-controlled steering when executing the computer program.

[0016] The present application also 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 test method for the variable transmission ratio strategy of the steer-by-wire control is implemented.

[0017] The present application provides a test method and product for a steer-by-wire variable transmission ratio strategy. By acquiring a vehicle dynamics model with a steer-by-wire variable transmission ratio strategy and a motion scenario for testing the steer-by-wire variable transmission ratio strategy, the steer-by-wire variable transmission ratio strategy is tested based on the vehicle dynamics model and the motion scenario to obtain test results. When the test results are unqualified, the steer-by-wire variable transmission ratio strategy is adjusted. The steer-by-wire variable transmission ratio strategy can be comprehensively and effectively tested, filling the gap in the test and verification of steer-by-wire variable transmission ratio strategies in the steer-by-wire field. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a flow chart of an embodiment of a test method for a variable transmission ratio strategy of steer-by-wire provided by the present application;

[0019] Figure 2 is a schematic diagram of a steering sensitivity test curve of an embodiment of a test method for a variable transmission ratio strategy of steer-by-wire provided in the present application;

[0020] Figure 3 It is a specific flow chart of an embodiment of a test method for a variable transmission ratio strategy of steer-by-wire provided by the present application;

[0021] Figure 4 is a structural schematic diagram of an embodiment of a test system for a variable transmission ratio strategy of steer-by-wire provided by the present application;

[0022] Figure 5is a schematic structural diagram of an embodiment of an electronic device provided by the present application;

[0023] Figure 6 It is a structural schematic diagram of another embodiment of the electronic device provided by the present application. DETAILED DESCRIPTION

[0024] The following will be combined with the drawings in the embodiments of the present application to clearly describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments in the present application belong to the scope of protection of this application.

[0025] The terms "first", "second", etc. in the specification and claims of the present application are used to distinguish similar objects, and are not used to describe a specific order or sequence. It should be understood that the data used in this way can be interchangeable under appropriate circumstances, so that the embodiments of the present application can be implemented in an order other than those illustrated or described here, and the objects distinguished by "first", "second", etc. are generally of one type, and the number of objects is not limited. For example, the first object can be one or more. In addition, "and / or" in the specification and claims represents at least one of the connected objects, and the character " / " generally indicates that the objects associated with each other are in an "or" relationship.

[0026] The test method for the variable transmission ratio strategy of the wire-controlled steering provided in the embodiment of the present application can be applied to the terminal, can also be applied to the server side, and can also be software running in the terminal or the server side. In some embodiments, the terminal can be a smart phone, a tablet computer, a laptop computer, a desktop computer, etc.; the server side can be configured as an independent physical server, or a server cluster or a distributed system composed of multiple physical servers, and can also be configured as a cloud server that provides basic cloud computing services such as cloud services, cloud databases, cloud computing, cloud functions, cloud storage, network services, cloud communications, middleware services, domain name services, security services, CDN, and big data and artificial intelligence platforms; the software can be an application of the test method for the variable transmission ratio strategy of the wire-controlled steering, etc., but is not limited to the above forms.

[0027] The test method of the variable transmission ratio strategy of steer-by-wire provided in the embodiment of the present application is described in detail below with reference to the accompanying drawings through specific embodiments.

[0028] See also Figure 1 , the embodiment of the present application provides a method for testing a variable transmission ratio strategy of steer-by-wire, comprising:

[0029] Step S101: Acquire a vehicle dynamics model, where the vehicle dynamics model has a steer-by-wire variable transmission ratio strategy;

[0030] Step S102: obtaining a motion scenario for testing a steer-by-wire variable transmission ratio strategy;

[0031] Step S103: testing the variable transmission ratio strategy of steer-by-wire based on the vehicle dynamics model and the motion scenario to obtain a test result;

[0032] Step S104: When the test result is unqualified, adjusting the steer-by-wire variable transmission ratio strategy.

[0033] A testing method for a steer-by-wire variable transmission ratio strategy provided in an embodiment of the present application obtains a vehicle dynamics model with a steer-by-wire variable transmission ratio strategy, and a motion scene for testing the steer-by-wire variable transmission ratio strategy, and tests the steer-by-wire variable transmission ratio strategy based on the vehicle dynamics model and the motion scene to obtain a test result, and adjusts the steer-by-wire variable transmission ratio strategy when the test result is unqualified. The steer-by-wire variable transmission ratio strategy can be comprehensively and effectively tested, filling the gap in the test and verification of steer-by-wire variable transmission ratio strategies in the field of steer-by-wire.

[0034] Acquiring the vehicle dynamics model in the above step S101 includes:

[0035] Obtain a suspension model, a body model, a tire model, an engine model and a steer-by-wire system model; wherein the steer-by-wire system model has a steer-by-wire variable transmission ratio strategy;

[0036] The vehicle dynamics model is determined based on the suspension model, body model, tire model, power model and steer-by-wire system model.

[0037] Optionally, the tire model may adopt the FTire model to avoid the shaking problem of other tire models (such as the Magic Formula model) at low speeds.

[0038] In the above step S102, the motion scene may include but is not limited to typical motion scenes such as turning motion scene and lane change motion scene. The motion scene for testing the steer-by-wire variable transmission ratio strategy may be flexibly determined based on the test parameters of the steer-by-wire variable transmission ratio strategy.

[0039] Taking the test parameter of steering sensitivity as an example, a steering motion scenario for testing the steering sensitivity of the steer-by-wire variable transmission ratio strategy can be obtained by building an intersection scenario that integrates multiple elements such as vehicles, lane standards, buckets, and weather.

[0040] Taking the corner limit position as an example of the test parameter, a steering motion scenario for testing the corner limit position of the steer-by-wire variable transmission ratio strategy can also be obtained by building an intersection scenario that integrates multiple elements such as vehicles, lane standards, pile barrels and weather.

[0041] Taking the low-speed threshold as an example of the test parameter, a straight three-lane scenario can be built that integrates multiple factors such as vehicles, lane standards, pile barrels and weather to obtain a lane-changing motion scenario for low-speed threshold testing of the steer-by-wire variable transmission ratio strategy.

[0042] In actual implementation, the vehicle dynamics model can be compiled into a dynamic driving simulator, and an intersection scene and a straight three-lane scene that integrates multiple factors such as vehicles, lane standards, buckets and weather can be built in the dynamic driving simulator. The driver can operate the dynamic driving simulator to simulate driving to conduct a virtual test of the variable transmission ratio strategy of steer-by-wire.

[0043] In the above step S103: based on the vehicle dynamics model and the motion scenario, the variable transmission ratio strategy of the steer-by-wire is tested, including:

[0044] Based on the vehicle dynamics model and steering motion scenario, the vehicle steering sensitivity test is performed to obtain the vehicle steering sensitivity test result;

[0045] Based on the vehicle dynamics model and steering motion scenario, the vehicle is tested for its corner limit position to obtain the test result of the vehicle's corner limit position;

[0046] Based on the vehicle dynamics model and lane-changing motion scenario, a low-speed threshold test is performed on the vehicle to obtain the low-speed threshold test result of the vehicle;

[0047] Among them, the test results include the vehicle's steering sensitivity test results, corner limit position test results and low-speed threshold test results.

[0048] Specifically, the variable transmission ratio of steer-by-wire has the functions of traditional mechanical steering variable transmission ratio, that is, the variable transmission ratio of steer-by-wire changes with the steering wheel angle (with the increase of the steering wheel angle, the change slope of the wheel angle will gradually increase), and the steering sensitivity refers to the performance of the change slope of the wheel angle dynamically responding to the change of the steering wheel angle when the steering wheel angle is 0 (also called the middle steering position). The steering angle limit position (also called the steering limit position) refers to the size of the steering wheel angle under the extreme wheel angle, which is determined by the size of the variable transmission ratio of steer-by-wire. The steering sensitivity and the steering angle limit position are both key indicators for evaluating the driving performance of the vehicle under the characteristic that the variable transmission ratio of steer-by-wire changes with the steering wheel angle. In addition, compared with the traditional mechanical steering variable transmission ratio, the steer-by-wire variable transmission ratio strategy adds a change relationship with vehicle speed, that is, the steer-by-wire variable transmission ratio changes with vehicle speed. The low-speed threshold is determined based on the steer-by-wire variable transmission ratio strategy. It is a key indicator for evaluating the driving performance of the vehicle under the characteristics of the steer-by-wire variable transmission ratio changing with vehicle speed at low speed. The range below the low-speed threshold is a fixed transmission ratio. Based on the vehicle dynamics model and motion scene, the steering sensitivity test, corner limit position test and low-speed threshold test of the vehicle can ensure the comprehensiveness of the test of the steer-by-wire transmission ratio strategy.

[0049] In some embodiments, the steering sensitivity test of the vehicle is performed based on the vehicle dynamics model and the steering motion scenario to obtain the steering sensitivity test result of the vehicle, including:

[0050] Based on the vehicle dynamics model, controlling the vehicle to perform a turning motion at a first speed in a turning motion scenario;

[0051] Determining a steering sensitivity test result of the vehicle at a first speed according to a first operating condition parameter and / or a first driving score during a steering movement of the vehicle;

[0052] The first operating condition parameter includes a steering wheel angle of the vehicle, and at least one of a lateral acceleration, a yaw rate, and a rack displacement of a steering rod of the vehicle.

[0053] Specifically, the driver operates the dynamic driving simulator to control the vehicle to perform steering movement at a uniform speed in a steering movement scenario at a first speed (such as 10km / h, 15km / h, 20km / h, etc.). The steering sensitivity test result of the vehicle at the first speed can be determined according to the driver's score of the vehicle's steering sensitivity during the vehicle's steering movement. The steering sensitivity test result of the vehicle at the first speed can also be determined according to the steering wheel angle of the vehicle collected during the vehicle's steering movement, and at least one of the vehicle's lateral acceleration, yaw angular velocity, and rack displacement of the steering rod. The steering sensitivity test result of the vehicle at the first speed can also be comprehensively determined according to the steering wheel angle of the vehicle collected during the vehicle's steering movement, and at least one of the vehicle's lateral acceleration, yaw angular velocity, and rack displacement of the steering rod, as well as the driver's score of the vehicle's steering sensitivity.

[0054] In view of the characteristic that the variable transmission ratio of the steer-by-wire system changes with the steering wheel angle, the present application controls the vehicle to perform a steering movement at a uniform speed at a first speed in a steering movement scenario based on a vehicle dynamics model, and determines a steering sensitivity test result of the vehicle at the first speed according to a first operating condition parameter and / or a first driving score during the vehicle's steering movement, thereby ensuring the effectiveness of the steering sensitivity test of the variable transmission ratio strategy of the steer-by-wire system.

[0055] In some embodiments, determining the steering sensitivity test result of the vehicle at the first speed according to the first operating condition parameter of the vehicle performing the steering motion includes:

[0056] Determine a steering wheel angle-lateral acceleration curve of the vehicle at a first speed according to the steering wheel angle of the vehicle and the lateral acceleration of the vehicle; and / or determine a steering wheel angle-yaw velocity curve of the vehicle at the first speed according to the steering wheel angle of the vehicle and the yaw velocity of the vehicle; and / or determine a steering wheel angle-steering rod rack displacement curve of the vehicle at the first speed according to the steering wheel angle of the vehicle and the rack displacement of the steering rod of the vehicle;

[0057] The steering sensitivity test result of the vehicle at the first speed is determined based on the slope of at least one of the steering wheel angle-lateral acceleration curve, the steering wheel angle-yaw rate curve, and the steering wheel angle-steering rod rack displacement curve of the vehicle at the first speed when the steering wheel angle is 0.

[0058] Exemplarily, a driver operates a dynamic driving simulator to control the vehicle to perform a left turn / right turn at an intersection at speeds of 10 km / h, 15 km / h and 20 km / h, respectively. The driver scores the steering sensitivity of the vehicle when performing a left turn / right turn at different speeds, and at the same time collects the steering wheel angle of the vehicle during the left turn / right turn at different speeds, and at least one of the vehicle's lateral acceleration, yaw angular velocity and rack displacement of the steering rod, and then draws a steering wheel angle-lateral acceleration curve, and / or a steering wheel angle-yaw angular velocity curve, and / or a steering wheel angle-steering rod rack displacement curve of the vehicle at different speeds, and then calculates the slope of the steering wheel angle-lateral acceleration curve, and / or the steering wheel angle-yaw angular velocity curve, and / or the steering wheel angle-steering rod rack displacement curve of the vehicle at different speeds when the steering wheel angle is 0. If at any speed, the driver's score of the vehicle's steering sensitivity when performing a left / right turn does not meet the standard, and / or when the steering wheel angle is 0, the vehicle's steering wheel angle-lateral acceleration curve, and / or the steering wheel angle-yaw angular velocity curve, and / or the steering wheel angle-steering rod rack displacement curve's slope does not meet the standard, then the steering sensitivity test result at the corresponding speed is an unqualified sensitivity test result. If at any speed, the driver's score of the vehicle's steering sensitivity when performing a left / right turn meets the standard, and when the steering wheel angle is 0, the vehicle's steering wheel angle-lateral acceleration curve, and / or the steering wheel angle-yaw angular velocity curve, and / or the steering wheel angle-steering rod rack displacement curve's slope meet the standard, then the steering sensitivity test result at the corresponding speed is a qualified sensitivity test result. Among them, the steering wheel angle-steering rod rack displacement curve is as follows: Figure 2 As shown, when the steering wheel angle is 0, the slope of the steering wheel angle-steering rod rack displacement curve is Figure 2 The magnitude of the slope of the straight line in .

[0059] In view of the characteristic that the variable transmission ratio of the steer-by-wire changes with the steering wheel angle, the present application specifically designs a test method for the variable transmission ratio strategy of the steer-by-wire at the steering neutral position. The steering sensitivity test result of the vehicle is determined by the steering wheel angle-lateral acceleration curve of the vehicle when the steering wheel angle is 0, and / or the steering wheel angle-yaw velocity curve, and / or the slope of the steering wheel angle-steering rod rack displacement curve, and / or the driver's driving score for the vehicle's steering movement, so as to ensure the effectiveness of the steer-by-wire variable transmission ratio strategy tested at the steering neutral position.

[0060] In some embodiments, the above-mentioned vehicle corner limit position test is performed on the vehicle based on the vehicle dynamics model and the steering motion scenario to obtain the vehicle corner limit position test result, including:

[0061] Based on the vehicle dynamics model, after the duration of the vehicle driving in a straight line at the second speed in the turning motion scene reaches a preset duration, the vehicle is continued to be controlled to perform a U-turn motion at a third speed in the turning motion scene;

[0062] Determining a turning angle limit position test result of the vehicle at a third speed according to a second operating condition parameter and a second driving score during the vehicle's U-turn movement;

[0063] The second operating condition parameters include the steering wheel angle and yaw rate of the vehicle.

[0064] Specifically, the driver operates the dynamic driving simulator, first controlling the vehicle to drive in a straight line at a second speed in a turning motion scenario, and after controlling the vehicle to drive in a straight line for a preset time, continuing to control the vehicle to perform a U-turn motion at a third speed in the turning motion scenario. The vehicle's steering wheel angle and yaw angular velocity collected during the U-turn motion are combined with the driver's driving score for the vehicle's U-turn motion to comprehensively determine the vehicle's corner limit position test result at the third speed.

[0065] In view of the characteristic that the variable transmission ratio of steer-by-wire changes with the steering wheel angle, the present application is based on a vehicle dynamics model. After controlling the vehicle to travel in a straight line at a second speed in a steering motion scenario for a preset time, the vehicle continues to be controlled at a third speed to perform a U-turn motion in the steering motion scenario. According to the second operating condition parameters and the second driving score of the vehicle during the U-turn motion, the corner limit position test result of the vehicle at the third speed is determined, thereby ensuring the effectiveness of the corner limit position test of the variable transmission ratio strategy of steer-by-wire.

[0066] In some embodiments, the above-mentioned determining the corner limit position test result of the vehicle at the third speed according to the second operating condition parameter and the second driving score during the vehicle performing the U-turn movement includes:

[0067] determining a steering wheel angle-yaw rate curve of the vehicle at a third speed according to the steering wheel angle and yaw rate of the vehicle;

[0068] determining a limit steering wheel angle of the vehicle at the third speed according to a steering wheel angle-yaw rate curve of the vehicle at the third speed;

[0069] The test result of the vehicle's corner limit position at the third speed is determined based on the limit steering wheel angle and the second driving score.

[0070] Exemplarily, the driver operates the dynamic driving simulator, first controls the vehicle to drive straight at a higher speed (40km / h-60km / h) in the intersection scene, controls the vehicle to drive straight for several seconds, and after the vehicle passes the intersection, quickly controls the vehicle to slow down to the third speed and perform a U-turn. Optionally, the third speed of the vehicle when performing a single-lane U-turn is less than 15km / h, and the third speed of the vehicle when performing a two-lane U-turn is ≥15km / h. During the vehicle's U-turn, a curve of the yaw rate-steering wheel angle of the vehicle at the third speed is drawn based on the collected steering wheel angle and yaw rate of the vehicle, and then the vehicle's limit steering wheel angle at the third speed is determined based on the yaw rate-steering wheel angle curve at the third speed, and combined with the driver's driving score of the vehicle's U-turn, it is determined whether the vehicle's limit steering wheel angle at the third speed meets the use requirements. If the vehicle's extreme steering wheel angle at the third speed meets the use requirements, the vehicle's extreme steering wheel angle at the third speed and the test result of the extreme steering wheel angle test being qualified are obtained. If the vehicle's extreme steering wheel angle at the third speed meets the use requirements, the vehicle's extreme steering wheel angle at the third speed and the test result of the extreme steering wheel angle test being unqualified are obtained.

[0071] In view of the characteristic that the variable transmission ratio of steer-by-wire changes with the steering wheel angle, the present application specifically designs a test method for the variable transmission ratio strategy of steer-by-wire at the steering extreme position. The vehicle's extreme steering wheel angle is determined by the vehicle's yaw rate-steering wheel angle curve, and the vehicle's steering angle extreme position test result is determined in combination with the driver's driving score of the vehicle performing a U-turn. This can ensure the effectiveness of the steer-by-wire variable transmission ratio strategy in the steering extreme position test.

[0072] In some embodiments, the low-speed threshold test is performed on the vehicle based on the vehicle dynamics model and the lane change motion scenario to obtain the low-speed threshold test result of the vehicle, including:

[0073] Based on the vehicle dynamics model, controlling the vehicle to perform a lane changing motion at a fourth speed in a lane changing motion scenario;

[0074] Determining a low-speed threshold test result of the vehicle according to a third operating condition parameter and / or a third driving score during the lane change process of the vehicle;

[0075] Among them, the difference between the fourth speed and the vehicle's low-speed threshold is within a preset range. The vehicle's low-speed threshold is determined based on the wire-controlled steer-by-wire variable transmission ratio strategy, and is pre-set based on the wire-controlled steer-by-wire variable transmission ratio strategy; the third operating condition parameters include the vehicle's movement duration and driving distance.

[0076] Specifically, the driver operates the dynamic driving simulator to control the vehicle to perform lane change in the lane change motion scene at the fourth speed. The low-speed threshold test result of the vehicle at the fourth speed can be determined based on the driver's dynamic response performance score of the vehicle's lane change during the vehicle's lane change. The low-speed threshold test result of the vehicle at the fourth speed can also be determined based on the vehicle's movement time and driving distance collected during the vehicle's lane change. The low-speed threshold test result of the vehicle at the fourth speed can also be comprehensively determined based on the vehicle's movement time and driving distance collected during the vehicle's lane change, as well as the driver's dynamic response performance score of the vehicle's lane change. Subsequently, based on the low-speed threshold test result of the vehicle at the fourth speed, it can be determined whether it is necessary to adjust the low-speed threshold by adjusting the steer-by-wire variable transmission ratio strategy.

[0077] In view of the characteristic that the variable transmission ratio of the steer-by-wire system changes with the vehicle speed, the present application controls the vehicle to execute lane changing motion at a fourth speed in a lane changing motion scenario based on a vehicle dynamics model, and determines the low-speed threshold test result of the vehicle according to the third operating condition parameters and / or the third driving score of the vehicle during the lane changing motion, thereby ensuring the effectiveness of the low-speed threshold test of the variable transmission ratio strategy of the steer-by-wire system.

[0078] In some embodiments, the method of determining the low speed threshold test result of the vehicle according to the third operating condition parameter during the lane change movement of the vehicle includes:

[0079] According to the movement duration and driving distance of the vehicle during the lane change process, it is determined whether the low speed threshold of the vehicle meets the driving requirements;

[0080] If the vehicle's low speed threshold meets the driving requirements, the vehicle's low speed threshold test is passed;

[0081] If the vehicle's low speed threshold does not meet the driving requirements, the vehicle's low speed threshold test fails.

[0082] For example, the driver operates the dynamic driving simulator to control the vehicle to perform a single-lane lane change / a two-lane lane change at the fourth speed in a straight three-lane scenario. The driver can comprehensively judge whether the low-speed threshold of the vehicle meets the driving requirements based on the movement duration and driving distance of the vehicle from the start to the end of the lane change collected during the lane change, and the driver's feeling of the duration and effect of the vehicle's lane change (including the flexibility of the variable transmission ratio strategy switching), and the vehicle's dynamic response performance score of the lane change movement. If the low-speed threshold of the vehicle meets the driving requirements, a test result of the low-speed threshold test of the vehicle is obtained. If the low-speed threshold of the vehicle does not meet the driving requirements, a test result of the low-speed threshold test of the vehicle is obtained.

[0083] In view of the characteristic that the variable transmission ratio of steer-by-wire changes with vehicle speed, the present application specifically designs a low-speed threshold test method for the variable transmission ratio strategy of steer-by-wire. The low-speed threshold test result of the vehicle is determined by the movement duration and driving distance of the vehicle during the lane change movement, and / or the driver's score of the dynamic response performance of the vehicle when executing the lane change movement, thereby ensuring the effectiveness of the low-speed threshold test of the variable transmission ratio strategy of steer-by-wire.

[0084] Figure 3 The present invention provides a method for testing a variable transmission ratio strategy for steer-by-wire, comprising:

[0085] Step S201: Acquire a vehicle dynamics model, where the vehicle dynamics model has a steer-by-wire variable transmission ratio strategy;

[0086] Step S202: obtaining a motion scenario for testing a steer-by-wire variable transmission ratio strategy;

[0087] Step S203: Based on the vehicle dynamics model and the motion scene, a steering sensitivity test, a corner limit position test and a low-speed threshold test are performed on the steer-by-wire variable transmission ratio strategy to obtain a steering sensitivity test result, a corner limit position test result and a low-speed threshold test result;

[0088] Step S204: determining whether the steering sensitivity test result, the corner limit position test result and the low speed threshold test result are all qualified;

[0089] If any one of the steering sensitivity test result, the corner limit position test result and the low speed threshold test result is unqualified, then executing step S205: adjusting the variable transmission ratio strategy of the steer-by-wire according to the unqualified test result, and updating the vehicle dynamics model, then returning to executing step S201, and then continuing to execute step S203;

[0090] If the steering sensitivity test results, the corner limit position test results and the low speed threshold test results are all qualified, step S206 is executed: the corner limit position constraint is performed on the steer-by-wire system model in the vehicle dynamics model to determine the final steer-by-wire variable transmission ratio strategy.

[0091] It is worth mentioning that, based on the vehicle dynamics model and steering motion scenario, the steering sensitivity test / corner limit position test at different speeds is performed on the variable transmission ratio strategy of the wire-controlled steer, and the steering sensitivity test results / corner limit position test results at multiple speeds are obtained. When the steering sensitivity test results / corner limit position test results at each speed are qualified, step S204 can determine that the steering sensitivity test results / corner limit position test results are qualified.

[0092] A test method for a steer-by-wire variable transmission ratio strategy provided in an embodiment of the present application includes several parts, including vehicle dynamics model building, motion scene construction, steering sensitivity test, corner limit position test, low-speed threshold test and final strategy generation. It not only provides a test method for the characteristics of the steer-by-wire variable transmission ratio strategy that change with the steering wheel angle, but also provides a test method for the characteristics of the steer-by-wire variable transmission ratio strategy that change with the vehicle speed. In a larger variable transmission ratio design space, it can ensure the comprehensiveness and effectiveness of the test of the variable transmission ratio strategy, especially the comprehensiveness and effectiveness of the test of the variable transmission ratio strategy at low speed, so that the design concept of the variable transmission ratio strategy is broader.

[0093] See also Figure 4 The embodiment of the present application also provides a test system 400 for a variable transmission ratio strategy of a wire-controlled steering system, which can implement the test method of the variable transmission ratio strategy of the wire-controlled steering system. The system includes: a first acquisition module 401, a second acquisition module 402 and a test module 403.

[0094] The first acquisition module 401 is used to acquire a vehicle dynamics model, and the vehicle dynamics model has a steer-by-wire variable transmission ratio strategy;

[0095] The second acquisition module 402 is used to acquire a motion scenario for testing the steer-by-wire variable transmission ratio strategy;

[0096] The testing module 403 is used to test the steer-by-wire variable transmission ratio strategy based on the vehicle dynamics model and the motion scene, obtain the test result, and adjust the steer-by-wire variable transmission ratio strategy when the test result is unqualified.

[0097] The test system for the variable transmission ratio strategy of the steer-by-wire provided in the embodiment of the present application can implement the various steps of the test method embodiment of the variable transmission ratio strategy of the steer-by-wire provided in the above-mentioned embodiment, and can achieve the same technical effect. To avoid repetition, it will not be described here.

[0098] Alternatively, if Figure 5 As shown, the embodiment of the present application also provides an electronic device 500, including a processor 501 and a memory 502, the memory 502 stores a program or instruction that can be run on the processor 501, and the program or instruction is executed by the processor 501 to implement the various steps of the test method embodiment of the variable transmission ratio strategy of the above-mentioned wire control steering, and can achieve the same technical effect. To avoid repetition, it is not repeated here. It should be noted that the electronic device in the embodiment of the present application includes the above-mentioned mobile electronic device and non-mobile electronic device.

[0099] Figure 6A schematic diagram of the hardware structure of an electronic device for implementing an embodiment of the present application is provided, wherein the electronic device includes:

[0100] The processor 601 may be implemented by a general-purpose CPU (Central Processing Unit), a microprocessor, an application-specific integrated circuit (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;

[0101] The memory 602 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 602 can store an operating system and other application programs. When the technical solution provided in the embodiment of this specification is implemented by software or firmware, the relevant program code is stored in the memory 602, and the processor 601 calls and executes the test method of the variable transmission ratio strategy of the wire control steering embodiment of the present application;

[0102] Input / output interface 603, used to implement information input and output;

[0103] Communication interface 604, used to realize communication interaction between the device and other devices, which can be realized by wired mode (such as USB, network cable, etc.) or wireless mode (such as mobile network, WIFI, Bluetooth, etc.);

[0104] Bus 605 , which transmits information between various components of the device (e.g., processor 601 , memory 602 , input / output interface 603 , and communication interface 604 );

[0105] The processor 601 , the memory 602 , the input / output interface 603 and the communication interface 604 are connected to each other in communication within the device via a bus 605 .

[0106] The electronic device provided in the embodiment of the present application can implement each step of the above-mentioned test method embodiment of the variable transmission ratio strategy of wire-controlled steering, and can achieve the same technical effect. To avoid repetition, it will not be repeated here.

[0107] An embodiment of the present application also provides a computer-readable storage medium, on which a program or instruction is stored. When the program or instruction is executed by a processor, each step of the test method embodiment of the above-mentioned wire-controlled steering variable transmission ratio strategy is implemented, and the same technical effect can be achieved. To avoid repetition, it will not be repeated here.

[0108] The processor is the processor in the electronic device described in the above embodiment. The computer-readable storage medium includes a computer-readable storage medium such as a computer read-only memory ROM, a random access memory RAM, a magnetic disk or an optical disk.

[0109] An embodiment of the present application further provides a chip, which includes a processor and a communication interface, wherein the communication interface is coupled to the processor, and the processor is used to run programs or instructions to implement the various steps of the above-mentioned test method embodiment for the variable transmission ratio strategy of wire-controlled steering, and can achieve the same technical effect. To avoid repetition, it will not be repeated here.

[0110] It should be understood that the chip mentioned in the embodiments of the present application can also be called a system-level chip, a system chip, a chip system or a system-on-chip chip, etc.

[0111] An embodiment of the present application provides a computer program product, which is stored in a storage medium. The program product is executed by at least one processor to implement the various steps of the test method embodiment of the variable transmission ratio strategy of the above-mentioned wire-controlled steering, and can achieve the same technical effect. To avoid repetition, it will not be repeated here.

[0112] It should be noted that, in this article, the terms "comprise", "include" or any other variant thereof are intended to cover non-exclusive inclusion, so that the process, method, article or device including a series of elements includes not only those elements, but also includes other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise one..." do not exclude the presence of other identical elements in the process, method, article or device including the element. In addition, it should be pointed out that the scope of the methods and devices in the embodiments of the present application is not limited to performing functions in the order shown or discussed, and may also include performing functions in a substantially simultaneous manner or in reverse order according to the functions involved, for example, the described method may be performed in an order different from that described, and various steps may also be added, omitted, or combined. In addition, the features described with reference to certain examples may be combined in other examples.

[0113] Through the description of the above implementation methods, those skilled in the art can clearly understand that the above-mentioned embodiment methods can be implemented by means of software plus a necessary general hardware platform, and of course by hardware, but in many cases the former is a better implementation method. Based on such an understanding, the technical solution of the present application, or the part that contributes to the prior art, can be embodied in the form of a computer software product, which is stored in a storage medium (such as ROM / RAM, a disk, or an optical disk), and includes a number of instructions for a terminal (which can be a mobile phone, a computer, a server, or a network device, etc.) to execute the methods described in each embodiment of the present application.

[0114] The embodiments of the present application are described above in conjunction with the accompanying drawings, but the present application is not limited to the above-mentioned specific implementation methods. The above-mentioned specific implementation methods are merely illustrative and not restrictive. Under the guidance of the present application, ordinary technicians in this field can also make many forms without departing from the purpose of the present application and the scope of protection of the claims, all of which are within the protection of the present application.

Claims

1. A test method for a variable transmission ratio strategy of steer-by-wire, characterized in that: include: obtaining a vehicle dynamics model, wherein the vehicle dynamics model has a steer-by-wire variable transmission ratio strategy; Acquiring a motion scenario for testing the steer-by-wire variable transmission ratio strategy; Based on the vehicle dynamics model and the motion scenario, the variable transmission ratio strategy of the steer-by-wire control is tested to obtain a test result; When the test result is unqualified, the steer-by-wire variable transmission ratio strategy is adjusted.

2. The testing method according to claim 1, characterized in that: The motion scenarios include steering motion scenarios and lane change motion scenarios; the testing of the variable transmission ratio strategy of the steer-by-wire based on the vehicle dynamics model and the motion scenarios includes: Based on the vehicle dynamics model and the steering motion scenario, performing a steering sensitivity test on the vehicle to obtain a steering sensitivity test result of the vehicle; Based on the vehicle dynamics model and the steering motion scenario, performing a turning angle limit position test on the vehicle to obtain a turning angle limit position test result of the vehicle; Based on the vehicle dynamics model and the lane change motion scenario, performing a low speed threshold test on the vehicle to obtain a low speed threshold test result of the vehicle; The test results include the steering sensitivity test results, the corner limit position test results and the low speed threshold test results of the vehicle.

3. The testing method according to claim 2, characterized in that: The step of performing a steering sensitivity test on a vehicle based on the vehicle dynamics model and the steering motion scenario to obtain a steering sensitivity test result of the vehicle includes: Based on the vehicle dynamics model, controlling the vehicle to perform a turning motion at a first speed in the turning motion scenario; determining a steering sensitivity test result of the vehicle at the first speed according to a first operating condition parameter and / or a first driving score during the vehicle performing the steering movement; The first operating condition parameter includes a steering wheel angle of the vehicle, and at least one of a lateral acceleration, a yaw rate, and a rack displacement of a steering rod of the vehicle.

4. The testing method according to claim 3, characterized in that: Determining a steering sensitivity test result of the vehicle at a first speed according to a first operating condition parameter of the vehicle in performing the steering motion includes: determining a steering wheel angle-lateral acceleration curve of the vehicle at the first speed according to the steering wheel angle of the vehicle and the lateral acceleration of the vehicle; and / or determining a steering wheel angle-yaw velocity curve of the vehicle at the first speed according to the steering wheel angle of the vehicle and the yaw velocity of the vehicle; and / or determining a steering wheel angle-steering rod rack displacement curve of the vehicle at the first speed according to the steering wheel angle of the vehicle and the rack displacement of the steering rod of the vehicle; The steering sensitivity test result of the vehicle at the first speed is determined based on the slope of at least one of the steering wheel angle-lateral acceleration curve, the steering wheel angle-yaw rate curve, and the steering wheel angle-steering rod rack displacement curve of the vehicle at the first speed when the steering wheel angle is 0.

5. The testing method according to claim 2, characterized in that: The step of performing a corner limit position test on the vehicle based on the vehicle dynamics model and the steering motion scenario to obtain a corner limit position test result of the vehicle includes: Based on the vehicle dynamics model, after the duration of the vehicle driving in a straight line at the second speed in the turning motion scene reaches a preset duration, the vehicle is continued to be controlled to perform a U-turn motion at a third speed in the turning motion scene; determining a turning angle limit position test result of the vehicle at the third speed according to a second operating condition parameter and a second driving score during the vehicle performing the U-turn movement; Wherein, the second operating condition parameters include the steering wheel angle and yaw angular velocity of the vehicle.

6. The testing method according to claim 5, characterized in that: The determining, according to the second operating condition parameter and the second driving score during the U-turn movement of the vehicle, a corner limit position test result of the vehicle at the third speed includes: determining a steering wheel angle-yaw rate curve of the vehicle at the third speed according to the steering wheel angle and the yaw rate of the vehicle; determining a limit steering wheel angle of the vehicle at the third speed according to a steering wheel angle-yaw rate curve of the vehicle at the third speed; A steering wheel angle limit position test result of the vehicle at the third speed is determined according to the steering wheel angle limit and the second driving score.

7. The testing method according to claim 2, characterized in that: The step of performing a low speed threshold test on the vehicle based on the vehicle dynamics model and the lane change motion scenario to obtain a low speed threshold test result of the vehicle includes: Based on the vehicle dynamics model, controlling the vehicle to perform a lane changing motion at a fourth speed in the lane changing motion scenario; determining a low-speed threshold test result of the vehicle according to a third operating condition parameter and / or a third driving score during the lane change movement of the vehicle; Among them, the difference between the fourth speed and the low-speed threshold of the vehicle is within a preset range, and the low-speed threshold of the vehicle is determined based on the variable transmission ratio strategy of the wire-controlled steering; the third operating condition parameter includes the movement duration and driving distance of the vehicle.

8. The testing method according to claim 7, characterized in that: Determining a low speed threshold test result of the vehicle according to a third operating condition parameter during the lane change movement of the vehicle includes: determining whether a low speed threshold of the vehicle meets driving requirements according to a movement duration and a travel distance of the vehicle during the lane change movement; If the low speed threshold of the vehicle meets the driving requirements, the low speed threshold test of the vehicle is passed; If the low speed threshold of the vehicle does not meet the driving requirements, the low speed threshold test of the vehicle fails.

9. The testing method according to claim 1, characterized in that: The obtaining of the vehicle dynamics model comprises: Acquire a suspension model, a vehicle body model, a tire model, an engine model and a steer-by-wire system model; wherein the steer-by-wire system model has the steer-by-wire variable transmission ratio strategy; The vehicle dynamics model is determined according to the suspension model, the vehicle body model, the tire model, the power model and the steer-by-wire system model.

10. A test system for a variable transmission ratio strategy of steer-by-wire, characterized in that: It includes a first acquisition module, a second acquisition module and a test module; The first acquisition module is used to acquire a vehicle dynamics model, wherein the vehicle dynamics model has a steer-by-wire variable transmission ratio strategy; The second acquisition module is used to acquire a motion scenario for testing the steer-by-wire variable transmission ratio strategy; The testing module is used to test the variable transmission ratio strategy of the steer-by-wire based on the vehicle dynamics model and the motion scenario to obtain a test result, and to adjust the variable transmission ratio strategy of the steer-by-wire when the test result is unqualified.

11. An electronic device, characterized in that: The electronic device comprises a memory and a processor, wherein the memory stores a computer program, and the processor implements the test method of the variable transmission ratio strategy of steer-by-wire as claimed in any one of claims 1 to 9 when executing the computer program.

12. A computer-readable storage medium storing a computer program, characterized in that: When the computer program is executed by a processor, the test method for a steer-by-wire variable transmission ratio strategy according to any one of claims 1 to 9 is implemented.

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