Method, device, equipment and storage medium for time-frequency synchronization control of four-wheel steering power assist in automobiles

Abstract

This invention discloses a method, device, equipment, and storage medium for time-frequency synchronous control of four-wheel steering assist in automobiles. The method includes: determining a normalization coefficient for the difference in target steering assist for each steering wheel based on the target steering assist change value of each steering wheel; determining a theoretical steering assist coefficient for each steering wheel based on the maximum change in steering assist for each steering wheel within a single task cycle; calculating and determining the current transient target steering assist for each steering wheel based on the normalization coefficient for the difference in target steering assist and the theoretical steering assist coefficient; and controlling the time required for the transient steering assist change of each steering wheel to reach its steady-state target steering assist to be equal. This invention considers the maximum change in steering assist for each steering wheel, thus avoiding over-capacity operation of the steering mechanism of each steering wheel; and controls the time required for the transient steering assist change of each steering wheel to reach its steady-state target steering assist to be equal, thus avoiding the problem of uncoordinated steering assist.

Description

Technical Field

[0001] This invention relates to the field of automotive steering control technology, and in particular to a method, device, equipment, and storage medium for time-frequency synchronous control of four-wheel steering assist in automobiles. Background Technology

[0002] As intelligent vehicles demand increasingly higher levels of intelligence, the steering systems of four-wheel intelligent vehicles have also evolved to feature independent steering control for each wheel, meeting the requirements for high maneuverability and handling stability. The independent control of the steering angle of each of the four wheels is achieved through the assistance applied by the steering gears of each wheel. However, this independent assistance may not simultaneously reach the target assistance values ​​set for all four wheels. Furthermore, excessive assistance during dynamic adjustment can lead to damage to the steering system or a reduced lifespan. Summary of the Invention

[0003] In view of the above-mentioned defects or improvement needs of the prior art, the purpose of this invention is to provide a method, device, equipment and storage medium for time-frequency synchronous control of four-wheel steering assist of automobiles.

[0004] To achieve this objective, the present invention adopts the following technical solution:

[0005] This invention provides a method for time-frequency synchronization control of four-wheel steering assist in automobiles, comprising:

[0006] Calculate the difference between the steady-state target steering assist of each steering wheel and the transient steering assist of each steering wheel at the previous moment, and determine the change value of the target steering assist of each steering wheel;

[0007] Based on the target steering assist change value of each steering wheel, determine the difference normalization coefficient of the target steering assist of each steering wheel;

[0008] The theoretical steering assist coefficient of each steering wheel is determined based on the maximum change in steering assist of each steering wheel within a single task cycle.

[0009] Based on the normalization coefficient of the difference in target steering assist of each steering wheel and the theoretical steering assist coefficient of each steering wheel, the control coefficient of the steering assist change and the steering assist execution change of each steering wheel are determined, thereby determining the current transient target steering assist of each steering wheel and controlling the time required for each steering wheel to change from transient steering assist to its steady-state target steering assist to be equal.

[0010] Furthermore, the step of determining the theoretical steering assist coefficient of each steering wheel based on the maximum change in steering assist of each steering wheel within a single task cycle includes:

[0011] The minimum value among the maximum changes in steering assist of each steering wheel is taken as the theoretical assist boundary change value of the whole vehicle.

[0012] The theoretical steering assist coefficient of each steering wheel is calculated by comparing the maximum change in steering assist of each steering wheel with the theoretical assist boundary change of the entire vehicle.

[0013] Furthermore, the step of determining the theoretical steering assist coefficient of each steering wheel based on the maximum change in steering assist of each steering wheel within a single task cycle includes the following:

[0014] Based on the theoretical maximum change in steering assist of each steering wheel per unit time, the maximum change in steering assist of each steering wheel within a single task cycle is calculated and determined.

[0015] Further, the step of determining the steering assist variation control coefficient and steering assist execution variation of each steering wheel based on the difference normalization coefficient of the target steering assist of each steering wheel and the theoretical steering assist coefficient of each steering wheel, and then determining the current transient target steering assist of each steering wheel, includes:

[0016] Based on the normalization coefficient of the difference in target steering assist of each steering wheel and the theoretical steering assist coefficient of each steering wheel, the formula is used to calculate the control coefficient of the assist change of each steering wheel.

[0017] The steering assist change of each steering wheel is determined by multiplying the maximum change in steering assist of each steering wheel within the single task cycle with the steering assist change control coefficient of each steering wheel.

[0018] Further, the step of calculating the steering assist variation control coefficient of each steering wheel based on the normalized coefficient of the difference in target steering assist of each steering wheel and the theoretical steering assist coefficient of each steering wheel includes:

[0019] Calculate the ratio of the normalized difference coefficient of the target steering assist of each steering wheel to its theoretical steering coefficient, and determine the maximum value among the ratios;

[0020] Based on the normalization coefficient of the difference in the target steering assist of each steering wheel and the maximum value among the ratios, the control coefficient of the assist change of each steering wheel is determined.

[0021] Furthermore, the calculation formula for the assist variation control coefficient of each steering wheel is as follows:

[0022] ;

[0023] in, for The constant-time left front steering wheel assist change control coefficient. for The normalized coefficient of the left front steering wheel at any given time. This is the theoretical steering assist coefficient for the left front steering wheel; for The constant-time power assist variation control coefficient for the right front steering wheel. for The normalized coefficient of the right front steering wheel at any given time. This is the theoretical steering assist coefficient for the right front steering wheel; for The control coefficient for the change in power assist of the left rear steering wheel at any given time. for The normalized coefficient of the left rear steering wheel at any given time. This is the theoretical steering assist coefficient for the left rear steering wheel; for The control coefficient for the change in power assist of the right rear steering wheel at any given time. for The normalized coefficient of the right rear steering wheel at any given time. This is the theoretical steering assist coefficient for the right rear steering wheel.

[0024] Furthermore, the step of determining the steering assist variation control coefficient and steering assist execution variation of each steering wheel based on the difference normalization coefficient of the target steering assist of each steering wheel and the theoretical steering assist coefficient of each steering wheel, and then determining the current transient target steering assist of each steering wheel, further includes:

[0025] The transient steering assist of each steering wheel at the current moment is calculated and determined based on the change in steering assist performance of each steering wheel and the transient steering assist of each steering wheel at the previous moment.

[0026] The present invention also provides a time-frequency synchronization control device for four-wheel steering power assist in automobiles, comprising:

[0027] The first module is used to calculate the difference between the steady-state target steering assist of each steering wheel and the transient steering assist of each steering wheel at the previous moment, and to determine the change value of the target steering assist of each steering wheel.

[0028] The second module is used to determine the difference normalization coefficient of the target steering assist of each steering wheel based on the target steering assist change value of each steering wheel;

[0029] The third module is used to determine the theoretical steering assist coefficient of each steering wheel based on the maximum change in steering assist of each steering wheel within a single task cycle.

[0030] The fourth module is used to determine the steering assist change control coefficient and steering assist execution change amount of each steering wheel based on the difference normalization coefficient of the target steering assist of each steering wheel and the theoretical steering assist coefficient of each steering wheel, thereby determining the current transient target steering assist of each steering wheel and controlling the time required for each steering wheel to change from transient steering assist to its steady-state target steering assist to be equal.

[0031] The present invention also provides an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the aforementioned automobile four-wheel steering power assist time-frequency synchronization control method.

[0032] The present invention also provides a computer-readable storage medium storing computer instructions that cause the computer to execute the aforementioned automobile four-wheel steering power assist time-frequency synchronization control method.

[0033] The beneficial effects of this invention are:

[0034] This invention provides a method, device, equipment, and storage medium for time-frequency synchronous control of four-wheel steering assist in automobiles. The method includes: calculating the difference between the steady-state target steering assist of each steering wheel and the transient steering assist of each steering wheel at the previous moment, and determining the target steering assist change value of each steering wheel; determining the difference normalization coefficient of the target steering assist of each steering wheel based on the target steering assist change value of each steering wheel; determining the theoretical steering assist coefficient of each steering wheel based on the maximum change value of steering assist of each steering wheel within a single task cycle; determining the steering assist change control coefficient and steering assist execution change amount of each steering wheel based on the difference normalization coefficient of the target steering assist of each steering wheel and the theoretical steering assist coefficient of each steering wheel, thereby determining the current transient target steering assist of each steering wheel, and controlling the time required for the transient steering assist of each steering wheel to change to its steady-state target steering assist to be equal.

[0035] On the one hand, when controlling the transient steering target assist of each steering wheel, the present invention takes into account the maximum change value of steering assist of each steering wheel within a single task cycle, which can avoid the problem of damage and reduced service life caused by the steering mechanical structure of each steering wheel working beyond its capacity, thus protecting the mechanical structure of the four-wheel steering of the car.

[0036] On the other hand, the present invention determines the control coefficient of the steering assist change and the steering assist execution change by proportional transformation. Through the calculation of the two, the current transient target steering assist of each steering wheel is obtained, and the time required for the transient steering assist of each steering wheel to change to its steady-state target steering assist is equal, so as to avoid the problem of uneven steering assist times for each steering wheel to change to its steady-state target steering assist, which leads to uncoordinated steering assist.

[0037] Additional aspects and advantages of this application will be set forth in part in the description which follows, and will become apparent from the description or may be learned by practice of this application. Attached Figure Description

[0038] The above and / or additional aspects and advantages of this application will become apparent and readily understood from the following description of the embodiments taken in conjunction with the accompanying drawings, wherein:

[0039] Figure 1 This is a flowchart of the time-frequency synchronization control method for four-wheel steering power assist in an embodiment of the present invention;

[0040] Figure 2 This is a schematic diagram of the time-frequency synchronization control device for four-wheel steering assist of an automobile in an embodiment of the present invention. Detailed Implementation

[0041] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, the accompanying drawings show only the parts relevant to the present invention, and not all of the structures.

[0042] In the description of this invention, unless otherwise explicitly specified and limited, the terms "connected," "linked," and "fixed" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0043] Those skilled in the art will understand that, unless otherwise stated, the singular forms “a,” “an,” “the,” and “the” used herein may also include the plural forms. It should be further understood that the word “comprising” as used in the specification of this application means the presence of the stated features, integers, steps, operations, elements, and / or components, but does not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or combinations thereof.

[0044] It will be understood by those skilled in the art that, unless otherwise defined, all terms used herein (including technical and scientific terms) have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains. It should also be understood that terms such as those defined in general dictionaries should be understood to have the same meaning as in the context of the prior art, and should not be interpreted in an idealized or overly formal sense unless specifically defined as in the embodiments of this application.

[0045] This application provides a method, device, equipment, and storage medium for time-frequency synchronization control of four-wheel steering assist in automobiles, applicable to four-wheel steering vehicles.

[0046] The flowchart of the automobile four-wheel steering power assist time-frequency synchronization control method provided in this embodiment is as follows: Figure 1 As shown, it includes steps S10-S60.

[0047] S10. Calculate the difference between the steady-state target steering assist of each steering wheel and the transient steering assist of each steering wheel at the previous moment, and determine the change value of the target steering assist of each steering wheel.

[0048] In this embodiment, the formula for calculating the target steering assist change value of each steering wheel is as follows:

[0049] ;

[0050] in, for The target steering assist change value of the left front steering wheel at any given time. for The target steering assist change value of the right front steering wheel at any given time. for The target steering assist change value of the left rear steering wheel at any given time. for The target steering assist change value of the right rear steering wheel at any given time. Provides steady-state target steering assistance to the left front steering wheel. To provide steady-state target steering assistance for the right front steering wheel. Provides steady-state target steering assistance to the left rear steering wheel. Provides steady-state target steering assistance to the right rear steering wheel. for The instantaneous steering assist of the left front steering wheel at all times. for The instantaneous steering assist of the right front steering wheel at all times. for The instantaneous steering assist of the left rear steering wheel at any moment. for Instantaneous steering assist of the right rear steering wheel at all times.

[0051] S20. Based on the target steering assist change value of each steering wheel, determine the difference normalization coefficient of the target steering assist of each steering wheel.

[0052] In this embodiment, the normalization coefficient of the difference in target steering assist for each steering wheel reflects the proportion of the absolute value of the change in target steering assist for each steering wheel in its total value.

[0053] S201. Calculate the sum of the absolute values ​​of the target steering assist change values ​​of each steering wheel to obtain the total target steering assist change value of the whole vehicle.

[0054] In this embodiment, the formula for calculating the total change in the target steering assist of the vehicle is as follows:

[0055] ;

[0056] in, for The total change in the target steering assist value of the whole vehicle at any time.

[0057] S202. Calculate the ratio of the target steering assist change value of each steering wheel to the total target steering assist change value of the whole vehicle, and determine the normalization coefficient of the difference in target steering assist of each steering wheel.

[0058] In this embodiment, the normalization coefficient for the difference in target steering assist for each steering wheel is:

[0059] ;

[0060] in, The normalized coefficient for the difference in target steering assist to the left front steering wheel. The normalized coefficient for the difference in target steering assist to the right front steering wheel. The normalized coefficient for the difference in target steering assist to the left rear steering wheel. The normalization coefficient for the difference in target steering assist to the right rear steering wheel.

[0061] It is understood that in this embodiment, the sum of the normalization coefficients of the difference in target steering assist for each steering wheel is equal to 1, and the normalization coefficients of each steering wheel satisfy the following:

[0062] ;

[0063] It is understandable that the mechanical structure characteristics of each steering wheel will affect its ability to change steering assist. Therefore, when determining the value of steering assist change for each steering wheel, the individual steering assist change capability of each steering wheel must also be considered.

[0064] S30. Based on the theoretical maximum change in steering assist of each steering wheel per unit time, calculate and determine the maximum change in steering assist of each steering wheel within a single task cycle.

[0065] In this embodiment, a single task cycle refers to the time interval between two sampling calculations, for example, from Time's up The interval between moments is called a task cycle, and the time of a single task cycle is denoted as . .

[0066] Furthermore, based on bench tests To determine the theoretical maximum change in steering assist for each steering wheel per unit time, the formula for calculating the maximum change in steering assist for each steering wheel is:

[0067] ;

[0068] in, This represents the theoretical maximum change in steering assist of the left front steering wheel per unit time. This represents the theoretical maximum change in steering assist for the right front steering wheel. This represents the theoretical maximum change in steering assist for the left rear steering wheel. This represents the theoretical maximum change in steering assist for the right rear steering wheel. This represents the maximum change in steering assist of the left front steering wheel within a single task cycle. This represents the maximum change in steering assist of the right front steering wheel within a single task cycle. This represents the maximum change in steering assist of the left rear steering wheel within a single task cycle. This represents the maximum change in steering assist of the right rear steering wheel within a single task cycle. The duration of a single task cycle. Unit of time.

[0069] It should be noted that in this embodiment, the maximum change in steering assist of each steering wheel during a single task cycle is a non-negative value. It is understood that the theoretical maximum change in steering assist of each steering wheel per unit time is determined by the mechanical structural characteristics of the steering wheel. However, in order not to damage the steering wheels, the absolute value of the actual change in steering assist of each steering wheel during a single task cycle should not exceed its respective maximum change in steering assist.

[0070] S40. Determine the theoretical steering assist coefficient of each steering wheel based on the maximum change in steering assist of each steering wheel within a single task cycle.

[0071] S401. Take the minimum value among the maximum changes in steering assist of each steering wheel as the theoretical assist boundary change value for the entire vehicle:

[0072] ;

[0073] in, This provides theoretical support for the boundary change values ​​of the entire vehicle.

[0074] S402. Based on the ratio between the maximum change in steering assist of each steering wheel and the theoretical assist boundary change of the entire vehicle, the theoretical steering assist coefficient of each steering wheel is calculated:

[0075] ;

[0076] in, This is the theoretical steering assist coefficient for the left front steering wheel. This is the theoretical steering assist coefficient for the right front steering wheel. This is the theoretical steering assist coefficient for the left rear steering wheel. This is the theoretical steering assist coefficient for the left rear steering wheel.

[0077] It is understood that in this embodiment, the theoretical steering assist coefficient of each steering wheel is greater than or equal to 1.

[0078] S50. Based on the normalization coefficient of the difference in target steering assist of each steering wheel and the theoretical steering assist coefficient of each steering wheel, determine the control coefficient of the steering assist change and the steering assist execution change of each steering wheel, and then determine the current transient target steering assist of each steering wheel, and control the time required for each steering wheel to change from transient steering assist to its steady-state target steering assist to be equal.

[0079] S501. Based on the normalization coefficient of the difference in target steering assist of each steering wheel and the theoretical steering assist coefficient of each steering wheel, the formula is used to calculate the control coefficient of the assist change of each steering wheel.

[0080] In this embodiment, the ratio of the difference normalization coefficient of the target steering assist of each steering wheel to its theoretical steering coefficient is calculated, and the maximum value among the ratios is determined. Then, based on the difference normalization coefficient of the target steering assist of each steering wheel and the maximum value among the ratios, the assist change control coefficient of each steering wheel is determined.

[0081] Furthermore, the formula for calculating the control coefficient of the assist variation of each steering wheel is as follows:

[0082] ;

[0083] in, for The constant-time left front steering wheel assist change control coefficient. for The constant-time power assist variation control coefficient for the right front steering wheel. for The control coefficient for the change in power assist of the left rear steering wheel at any given time. for Control coefficient for the change in power assist of the right rear steering wheel at any given time.

[0084] Furthermore, in this embodiment, the value of the power assist variation control coefficient for each steering wheel is less than or equal to its respective theoretical steering assist coefficient. For example, the derivation is performed using the power assist variation control coefficient of the left front steering wheel as an example:

[0085] ;

[0086] That is:

[0087] .

[0088] Furthermore, S502, based on the maximum change in steering assist of each steering wheel within a single task cycle and the steering assist change control coefficient of each steering wheel, the change in steering assist of each steering wheel is calculated by multiplying the values ​​to determine the amount of change in steering assist.

[0089]

[0090] in, The change in steering assist for the left front steering wheel. This represents the change in steering assist applied to the right front steering wheel. The change in steering assist for the left rear steering wheel. This refers to the change in steering assist applied to the right rear steering wheel.

[0091] Furthermore, in this embodiment, within any task cycle, the change in steering assist performance of each steering wheel will not exceed its respective maximum change value. Continuing with the derivation using the change in steering assist performance of the left front steering wheel as an example:

[0092] ;

[0093] in:

[0094] ;

[0095] Then we have:

[0096] ;

[0097] As can be seen, in this embodiment, the change in steering assist value of each steering wheel will not exceed its respective maximum change in steering assist value, thus avoiding overworking of the steering wheel's mechanical structure. In this embodiment, when controlling the transient steering target assist of each steering wheel, the maximum change in steering assist value of each steering wheel within a single task cycle is considered, which can avoid damage and reduced service life caused by overworking of the steering mechanical structure of each steering wheel, thus protecting the mechanical structure of the vehicle's four-wheel steering.

[0098] S503. Based on the change in steering assist of each steering wheel and the transient steering assist of each steering wheel at the previous moment, calculate and determine the transient steering assist of each steering wheel at the current moment:

[0099] ;

[0100] in, for The instantaneous steering assist of the left front steering wheel at all times. for Instantaneous steering assist on the right front steering wheel at all times.

[0101] Furthermore, for The sign function, for The sign function, for The sign function, for The symbolic function.

[0102] In this embodiment, if the target steering assist change value of a certain steering wheel is positive, it means that the transient steering assist of that steering wheel at the previous moment needs to be increased to achieve its steady-state target steering assist; if the target steering assist change value of a certain steering wheel is negative, it means that the transient steering assist of that steering wheel at the previous moment needs to be reduced to achieve its steady-state target steering assist. However, in this embodiment, the actual steering assist change values ​​of each steering wheel are non-negative. Therefore, when calculating the transient steering assist of each steering wheel at the current moment, the calculation formula needs to be determined based on the sign of the target steering assist change value of each steering wheel.

[0103] Furthermore, at the end of each task cycle, the transient steering assist of each steering wheel is updated. After multiple task cycles, the transient steering assist of each steering wheel will change to its steady-state target steering assist.

[0104] The time required for each steering wheel to change to the steady-state target steering assist is:

[0105] ;

[0106] in, This is the time required for the left front steering wheel to adjust to its steady-state target steering assist. This is the time required for the right front steering wheel to change to its steady-state target steering assist. This refers to the time required for the left rear steering wheel to adjust to its steady-state target steering assist. This is the time required for the right rear steering wheel to change to its steady-state target steering assist.

[0107] Furthermore:

[0108] ;

[0109] Furthermore, substituting the normalization coefficient calculation formula for each steering wheel into the above formula, we can obtain:

[0110] ;

[0111] It can be seen that the time required for each steering wheel to change to its steady-state target steering assist is equal, that is, the four steering wheels reach the steady-state target steering assist at the same moment, thus avoiding the problem of uncoordinated steering assist of the four steering wheels.

[0112] Specifically, in this embodiment, the steering assist change control coefficient and the steering assist execution change are determined by proportional transformation. Through the calculation of the two, the current transient target steering assist of each steering wheel is obtained, and the time required for the transient steering assist of each steering wheel to change to its steady-state target steering assist is equal, so as to avoid the problem of uneven steering assist times for each steering wheel to change to its steady-state target steering assist, which leads to uncoordinated steering assist.

[0113] The present invention also provides a time-frequency synchronization control device for four-wheel steering power assist in automobiles, the schematic diagram of which is shown below. Figure 2 As shown, it includes a first module 21, a second module 22, a third module 23, and a fourth module 24.

[0114] The first module 21 is used to calculate the difference between the steady-state target steering assist of each steering wheel and the transient steering assist of each steering wheel at the previous moment, and to determine the change value of the target steering assist of each steering wheel.

[0115] The second module 22 is used to determine the difference normalization coefficient of the target steering assist of each steering wheel based on the target steering assist change value of each steering wheel;

[0116] The third module 23 is used to determine the theoretical steering assist coefficient of each steering wheel based on the maximum change in steering assist of each steering wheel within a single task cycle.

[0117] The fourth module 24 is used to determine the control coefficient of the steering assist change and the steering assist execution change of each steering wheel based on the difference normalization coefficient of the target steering assist of each steering wheel and the theoretical steering assist coefficient of each steering wheel, and then determine the current transient target steering assist of each steering wheel, and control the time required to realize the transient steering assist change of each steering wheel to its steady-state target steering assist to be equal.

[0118] In some feasible implementations, the automotive four-wheel steering assist time-frequency synchronization control device provided in this embodiment can be implemented by a combination of hardware and software, or by software, which can be software in the form of programs and plug-ins, and includes a series of modules.

[0119] The present invention also provides an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement a method for time-frequency synchronization control of four-wheel steering assist in automobiles.

[0120] The present invention also provides a computer-readable storage medium storing computer instructions that enable a computer to execute a method for time-frequency synchronization control of four-wheel steering assist in automobiles.

[0121] It should be understood that although the steps in the flowcharts of the accompanying figures are shown sequentially as indicated by the arrows, these steps are not necessarily executed in the order indicated by the arrows. Unless explicitly stated herein, there is no strict order restriction on the execution of these steps, and they can be executed in other orders. Moreover, at least some steps in the flowcharts of the accompanying figures may include multiple sub-steps or multiple stages. These sub-steps or stages are not necessarily completed at the same time, but can be executed at different times, and their execution order is not necessarily sequential, but can be performed alternately or in turn with other steps or at least some of the sub-steps or stages of other steps.

[0122] The above description is only a partial embodiment of this application. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of this application, and these improvements and modifications should also be considered within the scope of protection of this application.

Claims

1. A time-frequency synchronization control method for automobile four-wheel steering assist, characterized by, include: Calculate the difference between the steady-state target steering assist of each steering wheel and the transient steering assist of each steering wheel at the previous moment, and determine the change value of the target steering assist of each steering wheel; Based on the target steering assist change value of each steering wheel, determine the difference normalization coefficient of the target steering assist of each steering wheel; The theoretical steering assist coefficient of each steering wheel is determined based on the maximum change in steering assist of each steering wheel within a single task cycle, including: taking the minimum value among the maximum change values ​​of steering assist of each steering wheel as the theoretical assist boundary change value of the whole vehicle; and calculating the theoretical steering assist coefficient of each steering wheel by the ratio of the maximum change value of steering assist of each steering wheel to the theoretical assist boundary change value of the whole vehicle. Based on the normalized coefficient of the difference in target steering assist of each steering wheel and the theoretical steering assist coefficient of each steering wheel, the control coefficient of the steering assist change and the steering assist execution change of each steering wheel are determined, thereby determining the current transient target steering assist of each steering wheel, and controlling the time required for each steering wheel to change from transient steering assist to its steady-state target steering assist to be equal, including: calculating the steering assist change control coefficient of each steering wheel according to the formula based on the normalized coefficient of the difference in target steering assist of each steering wheel and the theoretical steering assist coefficient of each steering wheel; and calculating the steering assist execution change of each steering wheel by multiplying the maximum change value of steering assist of each steering wheel within a single task cycle and the steering assist change control coefficient of each steering wheel. The step of calculating the steering assist variation control coefficient of each steering wheel based on the normalized difference coefficient of the target steering assist of each steering wheel and the theoretical steering assist coefficient of each steering wheel includes: calculating the ratio of the normalized difference coefficient of the target steering assist of each steering wheel to its theoretical steering coefficient, and determining the maximum value among the ratios; determining the steering assist variation control coefficient of each steering wheel based on the normalized difference coefficient of the target steering assist of each steering wheel and the maximum value among the ratios.

2. The method of claim 1, wherein the time and frequency synchronization control is performed in a four-wheel steering assist system of an automobile. Before the step of determining the theoretical steering assist coefficient of each steering wheel based on the maximum change in steering assist of each steering wheel within a single task cycle, the following steps are included: Based on the theoretical maximum change in steering assist of each steering wheel per unit time, the maximum change in steering assist of each steering wheel within a single task cycle is calculated and determined.

3. The method for time-frequency synchronous control of four-wheel steering assist in automobiles as described in claim 1, characterized in that, The formula for calculating the assist variation control coefficient of each steering wheel is as follows: ； in, for The constant-time left front steering wheel assist change control coefficient. for The normalized coefficient of the left front steering wheel at any given time. This is the theoretical steering assist coefficient for the left front steering wheel; for The constant-time power assist variation control coefficient for the right front steering wheel. for The normalized coefficient of the right front steering wheel at any given time. This is the theoretical steering assist coefficient for the right front steering wheel; for The control coefficient for the change in power assist of the left rear steering wheel at any given time. for The normalized coefficient of the left rear steering wheel at any given time. This is the theoretical steering assist coefficient for the left rear steering wheel; for The control coefficient for the change in power assist of the right rear steering wheel at any given time. for The normalized coefficient of the right rear steering wheel at any given time. This is the theoretical steering assist coefficient for the right rear steering wheel.

4. The method for time-frequency synchronous control of four-wheel steering assist in automobiles as described in claim 1, characterized in that, The step of determining the steering assist variation control coefficient and steering assist execution variation of each steering wheel based on the difference normalization coefficient of the target steering assist of each steering wheel and the theoretical steering assist coefficient of each steering wheel, and then determining the current transient target steering assist of each steering wheel, further includes: The transient steering assist of each steering wheel at the current moment is calculated and determined based on the change in steering assist performance of each steering wheel and the transient steering assist of each steering wheel at the previous moment.

5. A time-frequency synchronization control device for four-wheel steering assist in automobiles, used to implement the time-frequency synchronization control method for four-wheel steering assist in automobiles as described in any one of claims 1-4, characterized in that, include: The first module is used to calculate the difference between the steady-state target steering assist of each steering wheel and the transient steering assist of each steering wheel at the previous moment, and to determine the change value of the target steering assist of each steering wheel. The second module is used to determine the difference normalization coefficient of the target steering assist of each steering wheel based on the target steering assist change value of each steering wheel; The third module is used to determine the theoretical steering assist coefficient of each steering wheel based on the maximum change in steering assist of each steering wheel within a single task cycle. The fourth module is used to determine the steering assist change control coefficient and steering assist execution change amount of each steering wheel based on the difference normalization coefficient of the target steering assist of each steering wheel and the theoretical steering assist coefficient of each steering wheel, thereby determining the current transient target steering assist of each steering wheel and controlling the time required for each steering wheel to change from transient steering assist to its steady-state target steering assist to be equal.

6. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the processor executes the computer program, it implements the time-frequency synchronization control method for four-wheel steering assistance of automobiles as described in any one of claims 1 to 4.

7. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores computer instructions that cause the computer to perform the time-frequency synchronization control method for four-wheel steering assistance of an automobile as described in any one of claims 1 to 4.

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