Method for analyzing expected steering motion intensity based on motion state of steering wheel

Abstract

The invention is suitable for the technical field of automobiles, and provides an expected steering motion intensity analysis method based on the motion state of a steering wheel. And then analyzing the steering motion intensity expected by the driver by using the compensated steering intention torque and the constructed mapping model. According to the method, the influence caused by the hysteresis effect is effectively eliminated, the problem that the steering wheel torque cannot accurately describe the steering motion intensity expected by a current driver is solved, and a foundation is laid for achieving high-quality steering motion and customizing personalized steering experience.

Description

Technical Field

[0001] The invention belongs to the field of automobile technology, and in particular relates to a method for analyzing expected steering motion intensity based on a steering wheel motion state. Background Art

[0002] With the continuous progress of the automotive industry and the increasing demand of consumers, driving experience has become one of the core concerns of vehicle design and development. Modern consumers not only pursue the power performance and intelligence level of vehicles, but also pay more attention to the comfort, controllability and natural interaction between people and vehicles during driving. In this context, the steering system is a key link in the direct interaction between the driver and the vehicle, and its performance has a vital impact on the overall driving experience. In order to give the driver a more precise and natural steering experience, it is first necessary to accurately obtain the steering movement intensity expected by the driver. Only by fully understanding the driver's steering intention can the steering torque be accurately controlled, thereby improving the responsiveness and comfort of the steering system and satisfying consumers' pursuit of high-quality driving experience.

[0003] In the steering torque transmission path, the mechanical coupling characteristics between the steering wheel and the steering column will cause significant dynamic hysteresis. Therefore, the original steering wheel torque cannot accurately describe the driver's steering intention, and dynamic compensation for its hysteresis is required. Summary of the invention

[0004] The purpose of the embodiments of the present invention is to provide a method for analyzing the expected steering motion intensity based on the motion state of the steering wheel, aiming to solve the problems raised in the above-mentioned background technology.

[0005] The embodiment of the present invention is implemented as follows: a method for analyzing the expected steering motion intensity based on the steering wheel motion state, comprising the following steps: Step 1: Construct a mapping model formula between the driver's intended torque and the steering movement intensity he or she expects: Build a test scenario containing various cornering conditions based on a driving simulator, recruit drivers for the test, collect operation data and vehicle status information during the driving process, and use the collected data to perform parameter identification to complete the establishment of the mapping model; Step 2: Monitor the vehicle's motion state information such as the steering wheel angle, torque, and rotation acceleration; Step 3: Perform damping compensation and rotational inertia compensation based on the steering wheel torque and its motion state information, and after obtaining the steering intention torque, pass it to the mapping model; Step 4: Based on the steering intention torque obtained and the current vehicle speed, the mapping model constructed in step 1 (the relationship between the steering intention torque and the expected steering movement intensity at different vehicle speeds) is used to analyze and obtain the steering movement intensity expected by the driver at the current moment.

[0006] A further technical solution is that in the step 1, when constructing the mapping model, the physical quantity characterizing the steering motion intensity is first determined, and the steering wheel angle is selected as the steering motion intensity characterizing quantity in the low-speed state; in the non-low-speed state, the lateral acceleration is selected to characterize the steering motion intensity; Then we choose to use Stevens' law in the law of psychophysics to construct the formula. Stevens' law is as follows: ; In the formula Refers to the stimulus intensity of a physical quantity; Refers to the magnitude of the sensation caused by a stimulus; is an index that depends on the stimulus type or sensory modality; is a proportionality constant affected by physical units; Analysis shows that the actual torque and the torque felt by the driver satisfy Stevens' law, and the actual steering movement intensity and the steering movement intensity felt by the driver satisfy Stevens' law; at the same time, when the steering movement intensity felt by the driver is linearly related to the torque, the steering experience is ideal. In addition, due to the proportional constant Here, the vehicle speed will also affect it, so it is corrected to show the influence of speed; so the following relationship is finally obtained: ; ; The formula shows the relationship between the desired steering motion intensity and the torque after dynamic compensation. There are four parameters in total, namely , where is the proportionality constant affected by the units, represents the effect of speed on the strength coefficient, It is a power exponent determined by the type and intensity of physical stimulation.

[0007] Then, a test scenario with various cornering conditions is built based on the driving simulator, and drivers are recruited for the test. At the same time, the operation data and vehicle status information during the driving process are collected, and the least squares method is used to identify the parameters of the formula based on the collected data. The corresponding parameters can be obtained to obtain the final mapping model.

[0008] A further technical solution is to select 20 km / h as the dividing line between low-speed and non-low-speed states.

[0009] A further technical solution is that in step 3, the steering wheel torque is compensated to offset the influence of damping and rotational inertia, and the final steering intention torque is obtained, and the calculation formula is as follows: ; In the formula, refers to the steering intention torque, refers to the steering wheel torque, is the damping coefficient, refers to the equivalent moment of inertia, , Refers to the steering wheel speed and rotation acceleration.

[0010] The embodiment of the present invention provides a method for analyzing the expected steering motion intensity based on the steering wheel motion state, which dynamically compensates the rotational inertia and damping of the steering wheel torque, and then uses the compensated steering intention torque and the constructed mapping model to complete the analysis of the driver's expected steering motion intensity. This method effectively eliminates the influence of the hysteresis effect and avoids the problem that the steering wheel torque cannot accurately describe the current driver's expected steering motion intensity, which will lay the foundation for achieving high-quality steering motion and customized personalized steering experience. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 A flowchart of a method for analyzing expected steering motion intensity based on a steering wheel motion state provided by an embodiment of the present invention; Figure 2 A schematic diagram of a low-speed state mapping model in a method for analyzing expected steering motion intensity based on a steering wheel motion state provided by an embodiment of the present invention; Figure 3 A schematic diagram of a non-low-speed state mapping model in a method for analyzing expected steering motion intensity based on a steering wheel motion state provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0012] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0013] The specific implementation of the present invention is described in detail below in conjunction with specific embodiments.

[0014] like Figure 1 As shown, a method for analyzing expected steering motion intensity based on the steering wheel motion state is provided in one embodiment of the present invention, comprising the following steps: Step 1: Construct a mapping model formula between the driver's intended torque and the steering movement intensity he or she expects. Based on a driving simulator, build a test scenario containing various cornering conditions, recruit drivers for the test, collect operation data and vehicle status information during driving, use the collected data to perform parameter identification, and complete the establishment of the mapping model. Step 2: Monitor the vehicle's motion state information such as the steering wheel angle, torque, and rotation acceleration; Step 3: Perform damping compensation and rotational inertia compensation based on the steering wheel torque and its motion state information, and after obtaining the steering intention torque, pass it to the mapping model; Step 4: Based on the steering intention torque obtained and the current vehicle speed, the mapping model constructed in step 1 (the relationship between the steering intention torque and the expected steering movement intensity at different vehicle speeds) is used to analyze and obtain the steering movement intensity expected by the driver at the current moment.

[0015] As a preferred embodiment of the present invention, in step 1, the mapping model can be constructed in different ways, such as constructing a model formula and then parsing the model parameters using test data; or using a neural network to train with a large amount of test data. Here, the first method is taken as an example for introduction: First, we need to determine the physical quantity that characterizes the intensity of steering motion. Since the dynamic response of the steering system is not obvious at low speed, the steering wheel angle, which is relatively perceptible, is used as the quantity that characterizes the intensity of steering motion. In non-low speed state, the dynamic response of the steering system is relatively obvious, so the lateral acceleration is used to characterize the intensity of steering motion. At the same time, 20 km / h is selected as the dividing line between low speed and non-low speed state.

[0016] Then we choose to use Stevens' law in the law of psychophysics to construct the formula. Stevens' law is as follows: ; In the formula Refers to the stimulus intensity of a physical quantity; Refers to the magnitude of the sensation caused by a stimulus; is an index that depends on the stimulus type or sensory modality; is a proportionality constant that is affected by physical units.

[0017] Analysis shows that the actual torque and the torque felt by the driver satisfy Stevens' law, and the actual steering intensity and the steering intensity felt by the driver satisfy Stevens' law. Studies have also shown that when the steering intensity felt by the driver is linearly related to the torque, the steering experience is ideal. In addition, due to the proportional constant Here, the speed of the vehicle will also affect the value, so it is corrected to show the influence of speed. So the following relationship can be obtained in the end: ; ; The formula shows the relationship between the desired steering motion intensity and the torque after dynamic compensation. There are four parameters in total, namely ,in is a proportionality constant affected by units, represents the effect of speed on the strength coefficient, It is a power exponent determined by the type and intensity of physical stimulation.

[0018] Then, a test scenario with various cornering conditions is built based on the driving simulator, and drivers are recruited for the test. Operation data and vehicle status information during driving are collected, and the least squares method is used to identify the parameters of the formula based on the collected data. The corresponding parameters can be obtained to obtain the final mapping model.

[0019] As a preferred embodiment of the present invention, in step 3, the steering wheel torque is compensated to offset the influence of damping and rotational inertia, so as to obtain the final steering intention torque, and the calculation formula thereof is as follows: ; In the formula, refers to the steering intention torque, refers to the steering wheel torque, is the damping coefficient, refers to the equivalent moment of inertia, , Refers to the steering wheel speed and rotation acceleration.

[0020] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for analyzing the expected steering motion intensity based on the steering wheel motion state, characterized in that: The following steps are involved: Step 1: Construct a mapping model formula between the driver's intended torque and the steering motion intensity he or she expects, design an experiment and collect data, use the experimental data to perform parameter identification, and complete the establishment of the mapping model; Step 2: Monitor the steering wheel angle, torque and various motion state information of the vehicle; Step 3: According to the acquired steering wheel torque and its motion state information, damping compensation and rotational inertia compensation are performed to obtain the steering intention torque, which is then passed to the mapping model; Step 4: Based on the steering intention torque obtained and the current vehicle speed, the steering movement intensity expected by the driver at the current moment is obtained through mapping model analysis.

2. The method for analyzing the expected steering motion intensity based on the steering wheel motion state according to claim 1, characterized in that: In the step 1, when constructing the mapping model, the physical quantity characterizing the steering motion intensity is first determined, and the steering wheel angle is selected as the steering motion intensity characterizing quantity in the low-speed state; in the non-low-speed state, the lateral acceleration is selected to characterize the steering motion intensity; Then we choose to use Stevens' law in the law of psychophysics to construct the formula. Stevens' law is as follows: ； In the formula Refers to the stimulus intensity of a physical quantity; Refers to the magnitude of the sensation caused by a stimulus; is an index that depends on the stimulus type or sensory modality; is a proportionality constant affected by physical units; Since the actual torque and the torque felt by the driver satisfy Stevens' law, the actual steering movement intensity and the steering movement intensity felt by the driver satisfy Stevens' law; at the same time, when the steering movement intensity felt by the driver is linearly related to the torque, it is an ideal steering experience; and due to the proportional constant Here, the vehicle speed will also affect it, so it is corrected to show the influence of speed; so the following relationship is finally obtained: ； ； The formula shows the relationship between the desired steering motion intensity and the torque after dynamic compensation. There are four parameters in total, namely ,in is a proportionality constant affected by units, represents the effect of speed on the strength coefficient, It is a power index determined by the type and intensity of physical stimulation; After that, the experiment is designed to collect data, and the parameters of the formula are identified using the least square method based on the collected data. The corresponding parameters are obtained, that is, the final mapping model.

3. The method for analyzing the expected steering motion intensity based on the steering wheel motion state according to claim 2, characterized in that: 20 km / h is selected as the dividing line between low-speed and non-low-speed states.

4. The method for analyzing the expected steering motion intensity based on the steering wheel motion state according to claim 2, characterized in that: In step 3, the steering wheel torque is compensated to offset the influence of damping and rotational inertia, and the final steering intention torque is obtained, and the calculation formula is as follows: ； In the formula, refers to the steering intention torque, refers to the steering wheel torque, is the damping coefficient, refers to the equivalent moment of inertia, , Refers to the steering wheel speed and rotation acceleration.

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