A Vehicle Oblique Translation Method, System, Device and Medium

Abstract

The present invention discloses a vehicle oblique translation method, system, device and medium, which includes: calculating the moving direction of the front axle according to the steering angles of the two wheels of the front axle of the vehicle; synchronizing the moving direction of the front axle to the average steering angle of the rear axle; and controlling a power source to drive a steering rack to steer the rear wheels according to the average steering angle of the rear axle. The accuracy of the front axle steering angle and the axle moving angle is increased, thereby reducing the cumulative offset of the oblique translation, which helps to improve the driving experience.

Description

Technical Field

[0001] The present invention relates to the technical field of oblique movement of vehicles, and in particular, to a method, system, device and medium for oblique translation of vehicles. Background Art

[0002] Based on the improvement of the steer-by-wire technology, the front and rear wheel steering systems (EPS / RSS) will also gradually become mature. In addition to the application of the rear wheel steering system (RSS) in the body attitude adjustment under high-speed driving conditions of vehicles, the body attitude adjustment under low-speed conditions is derived. The coordinated operation of the front wheel steering and the rear wheel steering under low-speed driving conditions can reduce the turning radius of the vehicle or achieve oblique driving, meeting the personalized driving of customers.

[0003] In the prior art, for the models with electric power steering and configured with a rear wheel steering system (RSS) currently, for oblique translation, only the same-direction rotation of the front and rear wheels is simply achieved. The implementation scheme is mainly that the steering wheel angle sensor sends a steering (left / right) instruction to the rear wheel system, and the rear wheel system executes the requested instruction. Its disadvantages are as follows: The rear wheel system receives the instruction of the steering wheel angle sensor and thus completes a left turn or a right turn; the steering angle is controlled by the steering wheel angle signal of the steering wheel angle sensor, but it cannot ensure the accurate following of the steering angles of the front and rear wheels, resulting in the deviation of the crab travel route. And currently, the steer-by-wire technology makes up for the control of the front wheel angle by the electric power steering. The steering wheel angle and the steering torque can be independently designed. The steer-by-wire can calculate and send the signal value of the steering wheel angle by the EPS itself, and at the same time, it can also be used as a reference value for the rear wheel steering angle in the oblique translation mode, making the steering angles of the front and rear wheels relatively more fitting when the vehicle is obliquely translated. Its disadvantages are as follows: Whether it is steer-by-wire or electric power steering, when the vehicle turns, as the steering angle increases, the difference in the steering angles between the left front wheel and the right front wheel will also increase, and with the accumulation of time of the oblique movement of the vehicle, the driving trajectory of the vehicle will also change. Summary of the Invention

[0004] Embodiments of the present application provide a method, system, device and medium for oblique translation of vehicles, which at least partially solve the technical problem in the prior art that the accurate following of the steering angles of the front and rear wheels cannot be guaranteed, resulting in the deviation of the crab travel route, and achieve the technical effect of increasing the accuracy of the front axle steering angle and the axle movement angle, thereby reducing the cumulative offset of the oblique translation and improving the driving experience.

[0005] In a first aspect, to solve the above technical problem, an embodiment of the present invention provides the following technical solutions:

[0006] A method for oblique translation of a vehicle, comprising:

[0007] Calculating the moving direction of the front axle according to the steering angles of the two wheels of the front axle of the vehicle;

[0008] Synchronize the angle between the moving direction of the front axle and the main shaft to the average rotation angle of the rear axle;

[0009] According to the average rotation angle of the rear axle, control the power source to drive the steering rack for rear-wheel steering.

[0010] Optionally, the step of calculating the moving direction of the front axle according to the steering angles of the two wheels of the front axle of the vehicle further includes:

[0011] Obtain the steering angles of the two wheels of the front axle of the vehicle according to the steering wheel angle;

[0012] Calculate the moving direction of the front axle according to the angle between the two wheels of the front axle.

[0013] Optionally, the step of obtaining the steering angles of the two wheels of the front axle of the vehicle according to the steering wheel angle further includes:

[0014] Test the rotation angles of the two wheels of the front axle according to different steering wheel angles and generate a corresponding table;

[0015] Obtain the steering wheel angle in real time and find the steering angles of the two wheels of the front axle according to the table.

[0016] Optionally, the step of controlling the power source to drive the steering rack for rear-wheel steering further includes:

[0017] Calculate the rack position range according to the rack conversion coefficient and the average rotation angle of the rear axle;

[0018] Start the power source to drive the steering rack for rear-wheel steering according to the above position range.

[0019] Optionally, the step of calculating the rack position range according to the rack conversion coefficient and the average rotation angle of the rear axle further includes:

[0020] Obtain the corresponding data of the rack conversion coefficient, the average rotation angle of the rear axle and the rack position range through actual measurement of the vehicle, and establish a corresponding relationship according to the data;

[0021] Based on the above corresponding relationship, substitute the newly input average rotation angle of the rear axle to calculate the target rack position range.

[0022] Optionally, the step of establishing the corresponding relationship according to the data further includes:

[0023] Perform fitting with the average rotation angle of the rear axle and the rack position range as variables to obtain the target fitting function.

[0024] Optionally, the above method further includes:

[0025] When the steering angles of the two rear axles are greater than the preset angle value;

[0026] Obtain the corresponding rotation angles for the four-wheel diagonal driving of the above-mentioned vehicle through experiments, and establish a corresponding table;

[0027] Based on the data in the above table, match the rotation angles of the left and right wheels of the front axle, select the corresponding data of the left and right wheels of the rear axle in the table, and request the above power source to drive the steering rack for rear-wheel steering.

[0028] In a second aspect, a vehicle diagonal translation system is provided, and the above system includes:

[0029] A front axle calculation module for calculating the moving direction of the front axle according to the steering angles of the two wheels of the vehicle front axle;

[0030] A synchronization data module for synchronizing the included angle between the above-mentioned front axle moving direction and the main shaft to the average rear axle rotation angle;

[0031] A rear axle rotation angle module for controlling the power source to drive the steering rack for rear-wheel steering according to the above-mentioned average rear axle rotation angle.

[0032] In a third aspect, an electronic device is provided, including: a memory, a processor, and a computer program stored on the above-mentioned memory and executable on the above-mentioned processor. When the above-mentioned processor executes the above-mentioned computer program, the steps corresponding to the method in the first aspect are implemented.

[0033] In a fourth aspect, a computer-readable storage medium is provided, on which a computer program is stored, and when the program is executed by a processor, the steps corresponding to the method in the first aspect are implemented.

[0034] One or more technical solutions provided in the embodiments of the present application have at least the following technical effects or advantages:

[0035] Obtain the steering angle of the front axle through the steering wheel, then calculate the moving direction of the front axle according to the steering angle, and then calculate the steering angles of the left and right wheels of the rear axle from the moving direction of the front axle. It calculates the moving angle of the front axle by using the rotation angles of the left and right front wheels, and synchronizes the moving direction of the front axle and the average rear axle rotation angle, so as to accurately follow the steering angles of the front and rear wheels, increase the accuracy of the front axle steering angle and the axle moving angle, thereby reducing the cumulative offset of diagonal translation and helping to improve the driving experience. Description of the Drawings

[0036] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the following drawings are some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0037] Figure 1Flow chart of a vehicle diagonal translation method provided by this application;

[0038] Figure 2 Schematic diagram of the calculation principle of the vehicle diagonal translation method in this application;

[0039] Figure 3 Schematic diagram of the structure of a vehicle diagonal translation system provided by this application;

[0040] Figure 4 Schematic diagram of the structure of an electronic device provided by this application. Detailed implementation manners

[0041] To make the objectives, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Apparently, the described embodiments are some but not all of the embodiments of the present invention. The components of the embodiments of the present invention described and illustrated herein can be arranged and designed in various different configurations.

[0042] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed present invention, but merely represents selected embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the scope of protection of the present invention.

[0043] It should be noted that: like reference numerals and letters denote like items in the following drawings, and thus, once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings.

[0044] In the description of the present invention, it should also be noted that unless otherwise clearly defined and limited, the term "arrangement" should be understood in a broad sense. For example, it can be fixedly arranged, detachably arranged, or integrally arranged; it can be mechanically arranged or electrically arranged; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

[0045] It should be understood that the embodiments of the present invention and the specific features in the embodiments are detailed descriptions of the technical solutions of this application, rather than limitations on the technical solutions of this application. Without conflict, the technical features in the embodiments of this application and the embodiments can be combined with each other.

[0046] Embodiments of the present application provide a method, system, device, and medium for oblique translation of a vehicle, which improve the technical problem in the prior art that the accurate following of the steering angles of the front and rear wheels cannot be guaranteed, resulting in an offset of the crab-walking route, and achieve the technical effect of increasing the accuracy of the front axle steering angle and the axle movement angle, thereby reducing the cumulative offset of the oblique translation and enhancing the driving experience.

[0047] The technical solution of the embodiments of the present application for solving the above technical problem is generally as follows:

[0048] Obtain the steering angle of the front axle through the steering wheel, then calculate the moving direction of the front axle according to the steering angle, and then calculate the steering angles of the left and right wheels of the rear axle from the moving direction of the front axle. It calculates the front axle movement angle using the steering angles of the left and right front wheels, and synchronizes the data of the front axle movement direction and the average rear axle rotation angle, so as to accurately follow the steering angles of the front and rear wheels, increase the accuracy of the front axle steering angle and the axle movement angle, thereby reducing the cumulative offset of the oblique translation and helping to enhance the driving experience.

[0049] In the embodiments of the present application, there is provided a Figure 1 vehicle oblique translation method as shown below. The method includes steps S101 to S103:

[0050] Step S101: Calculate the moving direction of the front axle according to the steering angles of the two wheels of the front axle of the vehicle;

[0051] It should be noted that when the left and right wheels of the front axle rotate, generally the inner wheel rotates at a larger angle, that is, there is an Ackermann geometry relationship between the two wheels; its purpose is to have an angle difference between the rotation angles of the two steering wheels when the vehicle is turning, and the function of this angle difference is to make the vehicle body more stable when turning, reduce tire wear, and also reduce the turning radius. Therefore, it is necessary to calculate the moving direction of the front axle according to the rotation angles of the two wheels to facilitate the determination of the rear wheel direction.

[0052] Step S102: Synchronize the included angle between the above-mentioned front axle moving direction and the main axis to the average rear axle rotation angle;

[0053] It should be noted that after calculating the moving direction of the front axle, since the vehicle needs to perform oblique translation, it is necessary to keep the moving directions of the front axle and the rear axle consistent. However, the determination of the direction needs to be measured with a certain reference point. Therefore, the included angle a between the main axis and the front axle moving direction is used as the synchronized data and synchronized with the average rear axle rotation angle b to determine the moving direction of the rear axle, as Figure 2 shown.

[0054] Step S103: Control the power source to drive the steering rack to perform rear wheel steering according to the above-mentioned average rear axle rotation angle.

[0055] It should be noted that for the rear-wheel steering system, in fact, the vehicle controller controls the motor to drive the steering rack, and then drives the rear wheels to rotate. That is, it rotates synchronously according to the average angle of the rear axle and the moving direction of the front axle, achieving the effect of diagonal translation. Thereby reducing the cumulative offset of diagonal translation and helping to improve the driving experience.

[0056] Further, the step of calculating the moving direction of the front axle according to the steering angles of the two wheels of the front axle of the vehicle further includes:

[0057] Obtain the steering angles of the two wheels of the front axle of the vehicle according to the steering wheel angle;

[0058] Calculate the moving direction of the front axle according to the included angle between the two wheels of the front axle.

[0059] It should be noted that its calculation principle is as Figure 2 shown, and the specific calculation process is as follows:

[0060] Assume that the wheelbase of the front axle is L; draw an extension line of the wheelbase and an extension line of the intersection of the moving directions of the left and right wheel centers. The intersection of the two lines is O. The distance from the left wheel center to the intersection O is x, and the distance from the intersection of the moving directions of the left and right wheel centers to the point O is y; a1 is the steering angle of the left wheel of the front axle, a2 is the steering angle of the right wheel of the front axle, and the calculation process of the moving angle a of the front axle is:

[0061]

[0062]

[0063]

[0064] Combining formulas (1), (2) and (3) to obtain:

[0065]

[0066]

[0067] It can be seen from this that a is:

[0068]

[0069] Among them, Figure 2 the horizontal straight line of the included angle a represents the main shaft (i.e., the vehicle drive shaft), and the solid arrow is the moving direction of the front axle.

[0070] Further, the step of obtaining the steering angles of the two wheels of the front axle of the vehicle according to the steering wheel angle further includes:

[0071] Test the steering angles of the two wheels of the front axle according to different steering wheel angles and generate a corresponding table;

[0072] Obtain the steering angle of the above-mentioned steering wheel in real time, and look up the steering angles of the two front wheels of the front axle according to the above table.

[0073] It should be noted that since there is currently no sensor to directly obtain the wheel steering angle, here we use the traditional calibration test method to first obtain the left and right steering limits of the single front wheel through the steering wheel angle limit. For example, the left steering limit of the left front wheel is 40° to the left and 35° to the right, and the right steering limit of the right front wheel is 35° to the left and 40° to the right. Divide the range value from the left steering limit to the right steering limit of the steering wheel angle for equal division testing, as shown in the following table:

[0074]

[0075] Then look up the steering angles of the two front wheels of the front axle according to the above table.

[0076] Furthermore, the step of controlling the power source to drive the steering rack for rear-wheel steering further includes:

[0077] Calculate the rack position range according to the rack conversion coefficient and the average rear axle rotation angle;

[0078] Start the above-mentioned power source to drive the steering rack for rear-wheel steering according to the above position range.

[0079] It should be noted that since the rear-wheel steering system uses the steering rack to drive the rear wheels for steering, when controlling the specific steering angle of the rear wheels, it is necessary to calculate the position range of the gear and the rack movement in the steering rack, so as to achieve precise control.

[0080] Furthermore, the step of calculating the rack position range according to the rack conversion coefficient and the average rear axle rotation angle further includes:

[0081] Obtain the corresponding data of the rack conversion coefficient, the average rear axle rotation angle, and the rack position range through actual measurement of the above-mentioned vehicle, and establish a corresponding relationship according to the above data;

[0082] Based on the above corresponding relationship, substitute the newly input average rear axle rotation angle to calculate the target rack position range.

[0083] It should be noted that for the corresponding data of the rack conversion coefficient, the average rear axle rotation angle, and the rack position range, a large number of data measurements are carried out in the laboratory or road test, etc., and the corresponding relationship is established by fitting or deep learning according to the obtained data.

[0084] Furthermore, the step of establishing a corresponding relationship according to the above data further includes:

[0085] Perform fitting with the average rear axle rotation angle and the rack position range as variables to obtain the target fitting function.

[0086] It should be noted that the corresponding rack moves between (-s, s), where s is a positive value, that is, a = k * s, and k is the conversion coefficient between the rear wheel rotation angle and the rack position, which needs to be obtained by actual vehicle + simulation fitting. The value of k also changes at different rotation angles. The final fitting result will form a corresponding table (i.e., 1-D LookupTable), and finally, the motor is controlled to execute by requesting the table value. The fitting method can be to automatically fit after inputting data using existing software. For example, the cftool toolbox in matlab is used to fit the linear function relationship using the least squares method. That is, the formula a = b = k * s is used.

[0087] Further, the above method further includes:

[0088] When the steering angles of the two rear wheels of the rear axle are greater than the preset angle value;

[0089] Obtain the corresponding rotation angles of the four-wheel diagonal driving of the above vehicle through experiments and establish a corresponding table;

[0090] Based on the data in the above table, match the rotation angles of the left and right wheels of the front axle, select the corresponding data of the left and right wheels of the rear axle in the table, and request the above power source to drive the steering rack for rear wheel steering.

[0091] It should be noted that the existing rear wheel steering angle value is relatively low, so the angle difference between its left and right wheels can be ignored. However, with the gradual improvement of the rear wheel steering system, that is, the rear wheel system can achieve a larger steering angle in the future (for example, ±10°), then the rear wheel steering angle and the front wheel steering angle can be used for four-wheel digital simulation, and through the corresponding relationship table reserved inside the model, multiple data corresponding lookups can be realized, and then a more perfect crab walk (i.e., diagonal translation) can be achieved.

[0092] Based on the same inventive concept, an embodiment of the present application provides a vehicle diagonal translation system, as Figure 3 shown, including:

[0093] A front axle calculation module, configured to calculate the moving direction of the front axle according to the steering angles of the two front wheels of the vehicle;

[0094] A synchronization data module, configured to synchronize the included angle between the above front axle moving direction and the main shaft to the average rear axle rotation angle;

[0095] A rear axle rotation angle module, configured to control the power source to drive the steering rack for rear wheel steering according to the above average rear axle rotation angle.

[0096] Based on the same inventive concept, an embodiment of the present application provides an electronic device, as Figure 4As shown, it includes: a memory, a processor, and a computer program stored on the above-mentioned memory and executable on the above-mentioned processor. When the above-mentioned processor executes the above-mentioned computer program, a vehicle diagonal translation method is implemented.

[0097] Based on the same inventive concept, this embodiment provides a computer-readable storage medium with a computer program stored thereon, characterized in that when the program is executed by a processor, a vehicle diagonal translation method is implemented.

[0098] Those skilled in the art should understand that the embodiments of the present invention can be provided as a method, a system, or a computer program product. Therefore, the present invention can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Moreover, the present invention can take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk memory, CD-ROM, optical memory, etc.) containing computer-usable program code.

[0099] The present invention is described with reference to the flowcharts and / or block diagrams of methods, devices (systems), and computer program products according to the embodiments of the present invention. It should be understood that each flow and / or block in the flowchart and / or block diagram, as well as the combination of flows and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to the processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing devices to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing devices generate means for implementing the functions specified in one Figure 1 one flow or multiple flows and / or blocks Figure 1 one block or multiple blocks.

[0100] These computer program instructions can also be loaded onto a computer or other programmable data processing devices, so that a series of operation steps are executed on the computer or other programmable devices to generate a computer-implemented process. Thus, the instructions executed on the computer or other programmable devices provide steps for implementing the functions specified in one Figure 1 one flow or multiple flows and / or blocks Figure 1 one block or multiple blocks.

[0101] Although the preferred embodiments of the present invention have been described, those skilled in the art can make additional changes and modifications once they know the basic creative concept. Therefore, the appended claims are intended to be construed as including the preferred embodiments and all changes and modifications falling within the scope of the present invention.

[0102] Obviously, those skilled in the art can make various modifications and variations to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalent technologies, the present invention is also intended to include these modifications and variations.

Claims

1. A vehicle oblique translation method, characterized in that, The method includes: Calculating the moving direction of the front axle according to the steering angles of the two wheels on the front axle of the vehicle; the steering angles of the two wheels on the front axle are different; Synchronizing the angle between the moving direction of the front axle and the main axle to the average rear axle rotation angle; Controlling a power source to drive a steering rack to perform rear-wheel steering according to the average rear axle rotation angle; When the steering angles of the two rear wheels are greater than a preset angle value; Obtaining the corresponding rotation angles of the vehicle during four-wheel diagonal driving through experiments and establishing a corresponding table; Based on the data in the table, matching the rotation angles of the left and right wheels on the front axle, selecting the corresponding data of the left and right wheels on the rear axle in the table, and requesting the power source to drive the steering rack to perform rear-wheel steering.

2. The method according to claim 1, characterized in that The step of calculating the moving direction of the front axle according to the steering angles of the two wheels on the front axle of the vehicle further includes: Obtaining the steering angles of the two wheels on the front axle of the vehicle according to the steering wheel angle; Calculating the moving direction of the front axle according to the included angle between the two wheels on the front axle.

3. The method according to claim 2, characterized in that, The step of obtaining the steering angles of the two wheels on the front axle of the vehicle according to the steering wheel angle further includes: Testing the rotation angles of the two wheels on the front axle according to the rotation angles of different steering wheels and generating a corresponding table; Obtaining the rotation angle of the steering wheel in real time and looking up the steering angles of the two wheels on the front axle according to the table.

4. The method according to claim 1, wherein The step of controlling a power source to drive a steering rack to perform rear-wheel steering further includes: Calculating the rack position range according to the rack conversion coefficient and the average rear axle rotation angle; Starting the power source to drive the steering rack to perform rear-wheel steering according to the position range.

5. The method according to claim 4, characterized in that The step of calculating the rack position range according to the rack conversion coefficient and the average rear axle rotation angle further includes: Obtaining the corresponding data of the rack conversion coefficient, the average rear axle rotation angle and the rack position range through actual measurement of the vehicle, and establishing a corresponding relationship according to the data; Based on the corresponding relationship, substituting the newly input average rear axle rotation angle to calculate the target rack position range.

6. The method according to claim 5, characterized in that, The step of establishing the corresponding relationship according to the data further includes: Performing fitting with the average rear axle rotation angle and the rack position range as variables to obtain a target fitting function.

7. A vehicle diagonal translation system, characterized in that, The system includes: A front axle calculation module for calculating the moving direction of the front axle according to the steering angles of the two wheels on the front axle of the vehicle; the steering angles of the two wheels on the front axle are different; A synchronous data module for synchronizing the angle between the moving direction of the front axle and the main axle to the average rear axle rotation angle; A rear axle rotation angle module for controlling a power source to drive a steering rack to perform rear-wheel steering according to the average rear axle rotation angle; When the steering angles of the two rear wheels are greater than a preset angle value; Obtaining the corresponding rotation angles of the vehicle during four-wheel diagonal driving through experiments and establishing a corresponding table; Based on the data in the table, matching the rotation angles of the left and right wheels on the front axle, selecting the corresponding data of the left and right wheels on the rear axle in the table, and requesting the power source to drive the steering rack to perform rear-wheel steering.

8. An electronic device, characterized in that, The electronic device includes: a memory, a processor, and a computer program stored on the memory and executable on the processor, and when the processor executes the computer program, the method steps described in any one of claims 1 to 6 are implemented.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the program is executed by the processor, the steps corresponding to the method described in any one of claims 1 to 6 are implemented.

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