Steer-by-wire system and control method and control device therefor, storage medium

Abstract

The application discloses a steer-by-wire system and a control method and a control device thereof and a storage medium, the steer-by-wire system comprising a steering actuator configured to control a steering angle of a steering machine, the control method comprising: acquiring a wheel speed difference and a yaw angular velocity of a vehicle; when it is determined that the vehicle is in a straight driving state according to the wheel speed difference and / or the yaw angular velocity, acquiring the steering angle of the steering machine; determining a steering angle compensation value according to the steering angle of the steering machine, and controlling the steering actuator to control the steering angle of the steering machine according to the steering angle compensation value. The control method can ensure straight driving of the vehicle and improve user driving experience.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of vehicle control, in particular to a control method of a steer-by-wire system, a control device of a steer-by-wire system, a computer readable storage medium and a steer-by-wire system. BACKGROUND

[0002] Straight driving keeping ability is an evaluation index of vehicle driving performance, and a vehicle with good straight driving keeping ability can effectively relieve the operation intensity of a driver and improve driving comfort and driving safety. Therefore, how to keep a vehicle straight is an important research direction.

[0003] At present, the steer-by-wire system may cause vehicle deviation due to the different synchronization of the upper and lower motor angles, or due to the problems of vehicle left and right tire pressure and left and right suspension asymmetry, and the driver may need to always apply steering force to keep the vehicle straight, which brings poor experience to the user. SUMMARY

[0004] The present application aims to at least solve one of the technical problems in the related art. To this end, a first object of the present application is to provide a control method of a steer-by-wire system, which determines a steering angle compensation value according to a steering machine steering angle and controls a steering actuator to control the steering machine steering angle according to the steering angle compensation value, so as to ensure the straight driving of the vehicle and improve the user driving experience.

[0005] A second object of the present application is to provide a control device of a steer-by-wire system.

[0006] A third object of the present application is to provide a computer readable storage medium.

[0007] A fourth object of the present application is to provide a steer-by-wire system.

[0008] To achieve the above objects, a control method of a steer-by-wire system is provided in a first aspect of the present application, the steering system comprising a steering actuator configured to control a steering machine steering angle, the method comprising: obtaining a wheel speed difference and a yaw rate of the vehicle; when it is determined that the vehicle is in a straight driving state according to the wheel speed difference and / or the yaw rate, obtaining the steering machine steering angle; determining a steering angle compensation value according to the steering machine steering angle, and controlling the steering actuator to control the steering machine steering angle according to the steering angle compensation value.

[0009] The control method of the steer-by-wire steering system according to the embodiment of the present application firstly acquires the wheel speed difference and the yaw angular velocity of the vehicle, then acquires the steering machine steering angle when it is determined that the vehicle is in the straight driving state according to the wheel speed difference and / or the yaw angular velocity, and finally determines the steering angle compensation value according to the steering machine steering angle and controls the steering actuator to control the steering machine steering angle according to the steering angle compensation value. Thus, the method can ensure the straight driving of the vehicle and improve the user driving experience.

[0010] In addition, the control method of the steer-by-wire steering system according to the above-mentioned embodiments of the present application can further have the following additional technical features:

[0011] According to one embodiment of the present application, the determination of the steering angle compensation value according to the steering machine steering angle comprises: determining the opposite number of the steering machine steering angle as the steering angle compensation value.

[0012] According to one embodiment of the present application, the determination of the vehicle being in the straight driving state comprises: the wheel speed difference being less than the wheel speed limit value and the vehicle driving distance being greater than or equal to the preset distance; or the yaw angular velocity being less than the yaw angular velocity limit value and the vehicle driving distance being greater than or equal to the preset distance; or the wheel speed difference being less than the wheel speed limit value, the yaw angular velocity being less than the yaw angular velocity limit value, and the vehicle driving distance being greater than or equal to the preset distance.

[0013] According to one embodiment of the present application, the wheel speed difference is determined to be less than the wheel speed limit value when the front wheel speed difference is less than the first wheel speed limit value and the rear wheel speed difference is less than the second wheel speed limit value.

[0014] According to one embodiment of the present application, the first wheel speed limit value is determined by the following formula:

[0015]

[0016]

[0017]

[0018] wherein, V' represents the first wheel speed limit value, v1 represents the left rear wheel speed, v2 represents the right rear wheel speed, J r represents the rear wheel track, J f represents the front wheel track, a0 represents the angle between the outer side front wheel center and the rear wheel center to the turning center, L represents the wheelbase, R ro represents the outer side rear wheel turning radius, and R represents the turning radius of the vehicle.

[0019] According to one embodiment of the present application, the second wheel speed limit value is determined by the following formula:

[0020]

[0021]

[0022]

[0023] wherein V" represents a second wheel speed limit value, v3 represents a left front wheel speed, v4 represents a right front wheel speed, J f represents a front wheel track, J r represents a rear wheel track, L represents a wheelbase, a0 represents an angle between a center of an outer front wheel and a center of a rear wheel to a turning center, R ro represents a turning radius of the vehicle.

[0024] According to one embodiment of the present application, the yaw rate limit value is obtained by the following formula:

[0025]

[0026] wherein YR represents a yaw rate limit value, V represents a vehicle speed, and R represents a turning radius of the vehicle.

[0027] To achieve the above object, the second aspect of the present application provides a control device of a steer-by-wire system, the steer-by-wire system comprising a steering actuator configured to control a turning angle of a steering machine, the device comprising: a first obtaining module configured to obtain a wheel speed difference of the vehicle; a second obtaining module configured to obtain a yaw rate of the vehicle; a third obtaining module configured to obtain the turning angle of the steering machine when it is determined that the vehicle is in a straight running state according to the wheel speed difference and / or the yaw rate; and a control module configured to determine a turning angle compensation value according to the turning angle of the steering machine, and control the steering actuator to control the turning angle of the steering machine according to the turning angle compensation value.

[0028] According to the control device of the steer-by-wire system of the present application, the first obtaining module is configured to obtain a wheel speed difference of the vehicle, the second obtaining module is configured to obtain a yaw rate of the vehicle, the third obtaining module is configured to obtain the turning angle of the steering machine when it is determined that the vehicle is in a straight running state according to the wheel speed difference and / or the yaw rate, and the control module is configured to determine a turning angle compensation value according to the turning angle of the steering machine, and control the steering actuator to control the turning angle of the steering machine according to the turning angle compensation value. Thus, the device can ensure straight running of the vehicle and improve user driving experience.

[0029] To achieve the above object, the third aspect of the present application provides a computer readable storage medium having a control program of a steer-by-wire system stored thereon, the control program of the steer-by-wire system being executed by a processor to implement the control method of the steer-by-wire system.

[0030] According to the computer readable storage medium of the present application, the control method of the steer-by-wire system is implemented when executed, which can ensure straight running of the vehicle and improve user driving experience.

[0031] To achieve the above objectives, a steer-by-wire system is provided in the fourth aspect of the present invention, comprising a memory, a processor, and a steer-by-wire system control program stored in the memory and executable on the processor. When the processor executes the steer-by-wire system control program, it implements the above-described steer-by-wire system control method.

[0032] According to the steer-by-wire system of the present invention, by executing the above-described steer-by-wire system control method, the straight-line driving of the vehicle can be guaranteed, thereby improving the user's driving experience.

[0033] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0034] Figure 1 A flowchart of a control method for a steer-by-wire system according to an embodiment of the present invention;

[0035] Figure 2 This is a schematic diagram of vehicle driving deviation according to an embodiment of the present invention;

[0036] Figure 3 This is a schematic diagram of vehicle steering parameters according to an embodiment of the present invention;

[0037] Figure 4 A flowchart illustrating a control method for a steer-by-wire system according to a specific example of the present invention;

[0038] Figure 5 This is a block diagram of the control device of the steer-by-wire system according to an embodiment of the present invention;

[0039] Figure 6 This is a block diagram of a steer-by-wire system according to an embodiment of the present invention. Detailed Implementation

[0040] Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0041] The following description, with reference to the accompanying drawings, outlines the control method, control device, computer-readable storage medium, and steer-by-wire system of the present invention.

[0042] Figure 1 This is a flowchart of a control method for a steer-by-wire system according to an embodiment of the present invention.

[0043] As Figure 1 shown, the control method of the steer-by-wire steering system of the embodiment of the present application can include the following steps:

[0044] S1, obtaining the wheel speed difference and the yaw rate of the vehicle.

[0045] Specifically, when the vehicle is in a driving state, the front wheel speed difference of the vehicle and the rear wheel speed difference of the vehicle, and the yaw rate of the vehicle can be obtained. When obtaining the front wheel speed difference of the vehicle and the rear wheel speed difference of the vehicle, the wheel speed of each wheel can be obtained through a wheel speed sensor, and after obtaining the wheel speed of each wheel, the left and right wheel speed difference can be calculated. The yaw rate is a parameter describing the rotational motion of the vehicle around its center of gravity axis, and when obtaining the yaw rate of the vehicle, it can be obtained through a yaw rate sensor.

[0046] S2, obtaining the steering angle when determining that the vehicle is in a straight driving state according to the wheel speed difference and / or the yaw rate.

[0047] According to an embodiment of the present application, determining that the vehicle is in a straight driving state includes: the wheel speed difference is less than a wheel speed limit value, and the vehicle driving distance is greater than or equal to a preset distance; or the yaw rate is less than a yaw rate limit value, and the vehicle driving distance is greater than or equal to a preset distance; or the wheel speed difference is less than a wheel speed limit value, and the yaw rate is less than a yaw rate limit value, and the vehicle driving distance is greater than or equal to a preset distance. The preset distance can be determined according to the actual situation, for example, the preset distance can be 50 meters.

[0048] Specifically, the wheel speed difference and the yaw rate of the vehicle can be obtained through the above step S1, and when determining whether the vehicle is in the straight driving state, the wheel speed difference or the yaw rate of the vehicle can be used for judgment. For example, when the wheel speed difference is used to determine whether the vehicle is in the straight driving state, the wheel speed difference is compared with the wheel speed limit, and when the wheel speed difference is less than the wheel speed limit, and in order to make the result of the straight driving judgment more accurate, the driving distance of the vehicle also needs to be determined, and only when the driving distance of the vehicle is greater than or equal to a preset distance, for example, the distance of the normal driving distance of the vehicle is greater than or equal to 50 meters, it can be determined that the vehicle is currently in the straight driving state. Alternatively, when determining whether the vehicle is in the straight driving state, the yaw rate of the vehicle can also be used for judgment. For example, the yaw rate is compared with the yaw rate limit, and when the yaw rate is less than the yaw rate limit, and in order to make the result of the straight driving judgment more accurate, the driving distance of the vehicle also needs to be determined, and only when the driving distance of the vehicle is greater than or equal to a preset distance, for example, the distance of the normal driving distance of the vehicle is greater than or equal to 50 meters, it can be determined that the vehicle is currently in the straight driving state. Alternatively, when determining whether the vehicle is in the straight driving state, the wheel speed difference and the yaw rate of the vehicle can also be used for judgment. For example, the wheel speed difference is compared with the wheel speed limit, and the yaw rate is compared with the yaw rate limit, and when the wheel speed difference is less than the wheel speed limit and the yaw rate is less than the yaw rate limit, and in order to make the result of the straight driving judgment more accurate, the driving distance of the vehicle also needs to be determined, and only when the driving distance of the vehicle is greater than or equal to a preset distance, for example, the distance of the normal driving distance of the vehicle is greater than or equal to 50 meters, it can be determined that the vehicle is currently in the straight driving state.

[0049] According to one embodiment of the present application, when the front wheel speed difference is less than the first wheel speed limit and the rear wheel speed difference is less than the second wheel speed limit, it is determined that the wheel speed difference is less than the wheel speed limit.

[0050] Further, according to one embodiment of the present application, the first wheel speed limit is determined by the following formula:

[0051]

[0052]

[0053]

[0054] wherein, wherein V' represents the first wheel speed limit, v1 represents the left rear wheel speed, v2 represents the right rear wheel speed, J r represents the rear wheel track, J f represents the front wheel track, a0 represents the angle between the center of the outer front wheel and the center of the rear wheel to the center of the turn, L represents the wheelbase, R ro represents the turning radius of the outer rear wheel, and R represents the turning radius of the vehicle.

[0055] Specifically, when determining the first wheel speed limit, the turning radius of the vehicle can be calculated by taking a speed of 100 kph and a lateral deviation of 1 m after traveling 100 m. Figure 2 As shown, according to the Pythagorean theorem, the square of R plus the square of 100 equals the square of the sum of R and the offset, i.e., (R + offset). 2 =R 2 +100 2 When the offset is 1m, the vehicle's turning radius R can be approximately calculated to be 5000m. After obtaining the vehicle's turning radius R, combined with... Figure 3 As shown, the turning radius R of the outer rear wheel can be calculated according to the above formula (1). r0 It equals the vehicle's turning radius R plus the rear wheel track J. r Half of the turning radius R of the outer rear wheel of the vehicle. r0 Then, according to the above formula (1), that is, according to the vehicle wheelbase L, the vehicle rear wheel track J r and the front wheel track J of the vehicle f The angle R between the center of the outer front wheel and the center of the rear wheel and the turning center can be calculated. r0 Calculate the angle R between the center of the outer front wheel and the center of the rear wheel of the vehicle and the turning center. r0 Then, according to the above formula (1), that is, based on the left rear wheel speed V1, the right rear wheel speed V2, the vehicle wheelbase L, and the angle R between the center of the outer front wheel and the center of the rear wheel to the turning center. r0 The first wheel speed limit V′ is calculated from the tangent value. It should be noted that the front wheel track, rear wheel track, and wheelbase of the vehicle are fixed values, and their specific lengths can be determined based on the factory information when the vehicle leaves the factory.

[0056] According to one embodiment of the present invention, the second wheel speed limit is determined by the following formula:

[0057]

[0058]

[0059]

[0060] Where V″ represents the second wheel speed limit, v3 represents the left front wheel speed, v4 represents the right front wheel speed, and J f J represents the front wheel track. r The rear track width is represented by L, the wheelbase by α0, and the angle between the center of the outer front wheel and the center of the rear wheel and the turning center by R. ro This indicates the turning radius of the outer rear wheel, where R represents the turning radius of the vehicle.

[0061] Specifically, when determining the second wheel speed limit, the turning radius of the vehicle can be calculated by taking a lateral deviation of 1m when traveling 100m at a speed of 100kph. Figure 2 As shown, according to the Pythagorean theorem, the square of R plus the square of 100 equals the square of the sum of R and the offset, i.e., (R + offset). 2 =R 2 +100 2 When the offset is 1m, the vehicle's turning radius R can be approximately calculated to be 5000m. After obtaining the vehicle's turning radius R, combined with... Figure 3 As shown, the turning radius R of the outer rear wheel can be calculated according to the above formula (2). r0 It equals the vehicle's turning radius R plus the rear wheel track J. r Half of the turning radius R of the outer rear wheel of the vehicle. r0 Then, according to the above formula (2), that is, according to the vehicle wheelbase L, the vehicle rear wheel track J r and the front wheel track J of the vehicle f The angle R between the center of the outer front wheel and the center of the rear wheel and the turning center can be calculated. r0 Calculate the angle R between the center of the outer front wheel and the center of the rear wheel of the vehicle and the turning center. r0 Then, according to the above formula (2), that is, based on the left front wheel speed V3, the right front wheel speed V4, the vehicle wheelbase L, and the angle R between the center of the outer front wheel and the center of the rear wheel to the turning center. r0 The second wheel speed limit V″ is calculated from the tangent value. It should be noted that the front wheel track, rear wheel track, and wheelbase of the vehicle are fixed values, and their specific lengths can be determined based on the factory information when the vehicle leaves the factory.

[0062] After calculating the first wheel speed limit V′ and the second wheel speed limit V″ of the vehicle, if the current wheel speed difference is less than the first wheel speed limit V′, and at the same time the rear wheel speed difference is less than the second wheel speed limit V″, it can be determined that the wheel speed difference is less than the wheel speed limit, and thus it can be determined whether the vehicle is in a straight-going state based on the wheel speed difference.

[0063] According to one embodiment of the present invention, the yaw rate limit is obtained by the following formula:

[0064]

[0065] Where YR represents the yaw rate limit, V represents the vehicle speed, and R represents the vehicle's turning radius.

[0066] Specifically, the yaw rate limit can be calculated from the vehicle's lateral displacement over a fixed straight-line distance. For example, when determining the yaw rate limit, the turning radius of the vehicle can be calculated by taking a lateral displacement of 1m when traveling 100m at a speed of 100kph.Figure 2 As shown, according to the Pythagorean theorem, the square of R plus the square of 100 is equal to the square of the sum of R and the offset, i.e. (R+offset) 2 = R 2 +100 2 When the offset is 1 m, the turning radius R of the vehicle can be approximately calculated as 5000 m. After obtaining the turning radius R of the vehicle, the yaw rate limit YR can be calculated according to the above formula (3), i.e. according to the ratio between the vehicle speed V and the turning radius R of the vehicle. Thus, when the yaw rate is less than the yaw rate limit and the vehicle travel distance is greater than or equal to the preset distance, it is determined that the vehicle is in a straight running state.

[0067] When the vehicle is determined to be in a straight running state according to the wheel speed difference or the yaw rate, the steering actuator can be controlled to control the steering machine, and the steering angle of the steering machine can be obtained, for example, by a steering angle sensor, and it is considered that the current steering machine is at zero position. It should be noted that when the vehicle is determined to be in a straight running state according to both the wheel speed difference and the yaw rate, the average of the steering angles of the steering machine calculated by the two can be taken as the steering angle of the steering machine. If the vehicle is not determined to be in a straight running state according to the wheel speed difference or the yaw rate, the last calculated steering angle of the steering machine can be obtained.

[0068] S3, determining a steering angle compensation value according to the steering angle of the steering machine, and controlling the steering actuator to control the steering angle of the steering machine according to the steering angle compensation value.

[0069] According to an embodiment of the present application, determining a steering angle compensation value according to the steering angle of the steering machine comprises: determining the opposite number of the steering angle of the steering machine as the steering angle compensation value.

[0070] Specifically, after the above steps, after obtaining the steering angle of the steering machine, the steering angle compensation value can be determined according to the steering angle of the steering machine, for example, the obtained steering angle of the steering machine is x, and the opposite number -x of the steering angle of the steering machine x can be taken as the steering angle compensation value, i.e. the steering angle compensation value and the steering angle of the steering machine are equal in size and opposite in direction. After determining the steering angle compensation value, the steering angle compensation value can be stored in the memory, so that next time the vehicle is powered on, the steering actuator can be controlled to control the steering angle of the steering machine according to the steering angle compensation value. Thus, when the steering angle of the steering machine is controlled to be zero, the vehicle is in a straight running state, thereby improving the user driving experience.

[0071] The control method of the present application will be described below in conjunction with Figure 4 .

[0072] As a specific example, the control method of the steer-by-wire system of the present application can comprise the following steps:

[0073] S101, obtaining the wheel speed difference and the yaw rate of the vehicle.

[0074] S102, determine whether the vehicle is in a straight driving state according to the wheel speed difference and / or the yaw rate. If yes, execute step S103; if no, execute step S104.

[0075] S103, obtain the steering machine steering angle, and enter step S105.

[0076] S104, use the last obtained steering machine steering angle.

[0077] S105, determine the opposite number of the steering machine steering angle as the steering angle compensation value.

[0078] S106, control the steering actuator to control the steering machine steering angle according to the steering angle compensation value.

[0079] In summary, according to the control method of the steer-by-wire system according to the embodiment of the present application, first, the wheel speed difference and the yaw rate of the vehicle are obtained, then when it is determined that the vehicle is in a straight driving state according to the wheel speed difference and / or the yaw rate, the steering machine steering angle is obtained, and finally the steering angle compensation value is determined according to the steering machine steering angle, and the steering actuator is controlled to control the steering machine steering angle according to the steering angle compensation value. Therefore, the method can ensure the straight driving of the vehicle and improve the user driving experience.

[0080] Corresponding to the above-mentioned embodiment, the present application also provides a control device of a steer-by-wire system.

[0081] As shown in Figure 5 , the control device 100 of the steer-by-wire system according to the embodiment of the present application can include a first obtaining module 110, a second obtaining module 120, a third obtaining module 130 and a control module 140.

[0082] The first obtaining module 110 is configured to obtain the wheel speed difference of the vehicle. The second obtaining module 120 is configured to obtain the yaw rate of the vehicle. The third obtaining module 130 is configured to obtain the steering machine steering angle when it is determined that the vehicle is in a straight driving state according to the wheel speed difference and / or the yaw rate. The control module 140 is configured to determine the steering angle compensation value according to the steering machine steering angle, and control the steering actuator to control the steering machine steering angle according to the steering angle compensation value.

[0083] According to one embodiment of the present application, the control module 140 determines the steering angle compensation value according to the steering machine steering angle, specifically configured to determine the opposite number of the steering machine steering angle as the steering angle compensation value.

[0084] According to one of the embodiments of the present application, the third obtaining module 130 determines that the vehicle is in the straight driving state, specifically for: the wheel speed difference is less than the wheel speed limit value, and the vehicle driving distance is greater than or equal to the preset distance; or the yaw rate is less than the yaw rate limit value, and the vehicle driving distance is greater than or equal to the preset distance; or the wheel speed difference is less than the wheel speed limit value, and the yaw rate is less than the yaw rate limit value, and the vehicle driving distance is greater than or equal to the preset distance.

[0085] According to one of the embodiments of the present application, the third obtaining module 130 is further configured to determine that the wheel speed difference is less than the wheel speed limit value when the front wheel speed difference is less than the first wheel speed limit value and the rear wheel speed difference is less than the second wheel speed limit value.

[0086] According to one of the embodiments of the present application, the third obtaining module 130 determines the first wheel speed limit value by the following formula:

[0087]

[0088]

[0089]

[0090] wherein, V' represents the first wheel speed limit value, v1 represents the left rear wheel speed, v2 represents the right rear wheel speed, J r represents the rear wheel track, J f represents the front wheel track, a0 represents the angle between the center of the outer front wheel and the center of the rear wheel to the center of the turn, L represents the wheelbase, R ro represents the outer rear wheel turn radius, and R represents the turn radius of the vehicle.

[0091] According to one of the embodiments of the present application, the third obtaining module 130 determines the second wheel speed limit value by the following formula:

[0092]

[0093]

[0094]

[0095] wherein, V" represents the second wheel speed limit value, v3 represents the left front wheel speed, v4 represents the right front wheel speed, J f represents the front wheel track, J r represents the rear wheel track, L represents the wheelbase, a0 represents the angle between the center of the outer front wheel and the center of the rear wheel to the center of the turn, R ro represents the outer rear wheel turn radius, and R represents the turn radius of the vehicle.

[0096] According to one embodiment of the present application, the third obtaining module 130 obtains the yaw rate limit value by the following formula:

[0097]

[0098] wherein YR represents the yaw rate limit value, V represents the vehicle speed of the vehicle, and R represents the turning radius of the vehicle.

[0099] It should be noted that details not disclosed in the control device of the steer-by-wire system of the embodiments of the present application can refer to the details disclosed in the control method of the steer-by-wire system of the embodiments of the present application, which will not be described here in detail.

[0100] According to the control device of the steer-by-wire system of the embodiments of the present application, the first obtaining module is configured to obtain the wheel speed difference of the vehicle, the second obtaining module is configured to obtain the yaw rate of the vehicle, the third obtaining module is configured to obtain the steering machine rotation angle when it is determined that the vehicle is in the straight driving state according to the wheel speed difference and / or the yaw rate, and the control module is configured to determine the rotation angle compensation value according to the steering machine rotation angle and control the steering actuator to control the steering machine rotation angle according to the rotation angle compensation value. Thus, the device can ensure the straight driving of the vehicle and improve the user driving experience.

[0101] Corresponding to the above-mentioned embodiments, the present application further provides a computer readable storage medium.

[0102] The computer readable storage medium of the embodiments of the present application has a control program of the steer-by-wire system stored thereon, and the control program of the steer-by-wire system is executed by the processor to realize the above-mentioned control method of the steer-by-wire system.

[0103] According to the computer readable storage medium of the embodiments of the present application, by executing the above-mentioned control method of the steer-by-wire system, the straight driving of the vehicle can be ensured and the user driving experience can be improved.

[0104] Corresponding to the above-mentioned embodiments, the present application further provides a steer-by-wire system.

[0105] As shown in Figure 6 The steer-by-wire system 200 of the embodiments of the present application can include a memory 210, a processor 220, and a control program of the steer-by-wire system stored on the memory 210 and executable on the processor 220, and the processor 220 executes the control program of the steer-by-wire system to realize the above-mentioned control method of the steer-by-wire system.

[0106] According to the steer-by-wire system of the embodiments of the present application, by executing the above-mentioned control method of the steer-by-wire system, the straight driving of the vehicle can be ensured and the user driving experience can be improved.

[0107] It is to be appreciated that the above description and the examples that follow are intended to be illustrative only and that changes can be made to the description, as represented by the above listed elements, by the steps recited in the flow charts, and by the examples that follow, without departing from the spirit of the application. Accordingly, the scope of the present application is intended to be defined only by the appended claims.

[0108] It should be understood that aspects of the application can be implemented in hardware, software, firmware or a combination thereof. In the above embodiments, various steps or methods can be implemented in software or firmware that is stored in memory and executed by a suitable instruction execution system. For example, if implemented in hardware, as in another embodiment, any of the following techniques, which are well known in the art of hardware implementation, can be used: a hybrid of the above techniques, a mixture of two or more of the above techniques, or a combination of the above techniques with other techniques not listed above.

[0109] In the description of the present application, the terms "one embodiment", "some embodiments", "an example", "a specific example", or "some examples" are intended to mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the present application. The illustrative appearances of the above-mentioned terms in various places in the specification are not intended to exclude that the terms in one place can refer to the same or similar features, structures, materials, or characteristics as other instances of the same term found in another location in the specification. Furthermore, the description of particular features, structures, materials, or characteristics in

[0110] In addition, the terms "first", "second", etc. are used only for the purpose of description, and should not be understood as indicating or implying relative importance or implying a number of the technical features indicated. Therefore, the features defined as "first", "second" can explicitly or implicitly include at least one of the features. In the description of the present application, the meaning of "a plurality of" is at least two, for example, two, three, etc., unless otherwise explicitly specified and limited.

[0111] In the present application, unless otherwise explicitly specified and limited, the terms "mounting", "connecting", "connecting", "fixing" and the like should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or it can be integrated; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium; it can be the internal communication of two elements or the interaction relationship between two elements, unless otherwise explicitly limited. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0112] Although the embodiments of the present application have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be understood as limiting the present application, and those skilled in the art can make changes, modifications, replacements and variations to the above embodiments within the scope of the present application.

Claims

1. A control method for a steer-by-wire system, characterized in that, The steering system includes a steering actuator configured to control the steering angle of the steering gear, and the method includes: Obtain the wheel speed difference and yaw rate of the vehicle; When it is determined that the vehicle is in a straight-line state based on the wheel speed difference and / or the yaw rate, the steering gear angle is obtained; The steering angle compensation value is determined based on the steering gear angle, and the steering actuator is controlled to control the steering gear angle based on the steering angle compensation value; Determining that the vehicle is traveling straight includes: The wheel speed difference is less than the wheel speed limit, and the vehicle travel distance is greater than or equal to a preset distance; or The yaw rate is less than the yaw rate limit, and the vehicle travel distance is greater than or equal to the preset distance; or The wheel speed difference is less than the wheel speed limit, the yaw rate is less than the yaw rate limit, and the vehicle travel distance is greater than or equal to the preset distance. When the front wheel speed difference is less than the first wheel speed limit and the rear wheel speed difference is less than the second wheel speed limit, the wheel speed difference is determined to be less than the wheel speed limit. The first wheel speed limit is determined using the following formula: in, This indicates the first wheel speed limit. Indicates the speed of the left rear wheel. Indicates the speed of the right rear wheel. Indicates the rear wheel track. Indicates the front wheel track. This indicates the angle between the center of the outer front wheel and the center of the rear wheel and the center of the turn. Indicates wheelbase. Indicates the turning radius of the outer rear wheel. This indicates the vehicle's turning radius.

2. The control method for the steer-by-wire system according to claim 1, characterized in that, Determining the steering angle compensation value based on the steering gear angle includes: The opposite of the steering gear angle is determined as the steering angle compensation value.

3. The control method for the steer-by-wire system according to claim 1, characterized in that, The second wheel speed limit is determined using the following formula: in, This indicates the second wheel speed limit. Indicates the speed of the left front wheel. Indicates the speed of the right front wheel. Indicates the front wheel track. Indicates the rear wheel track. Indicates wheelbase. This indicates the angle between the center of the outer front wheel and the center of the rear wheel and the center of the turn. Indicates the turning radius of the outer rear wheel. This indicates the vehicle's turning radius.

4. The control method for the steer-by-wire system according to claim 1, characterized in that, The yaw rate limit is obtained using the following formula: in, This indicates the yaw rate limit. Indicates the vehicle's speed. This indicates the vehicle's turning radius.

5. A control device for a steer-by-wire system, characterized in that, The steer-by-wire system includes a steering actuator configured to control the angle of the steering gear, and the device includes: The first acquisition module is used to acquire the wheel speed difference of the vehicle; The second acquisition module is used to acquire the yaw rate of the vehicle; The third acquisition module is used to acquire the steering gear angle when it is determined that the vehicle is in a straight-line state based on the wheel speed difference and / or the yaw rate; The control module is used to determine the steering angle compensation value based on the steering gear angle, and to control the steering actuator to control the steering gear angle based on the steering angle compensation value; Determining that the vehicle is traveling straight includes: The wheel speed difference is less than the wheel speed limit, and the vehicle travel distance is greater than or equal to a preset distance; or The yaw rate is less than the yaw rate limit, and the vehicle travel distance is greater than or equal to the preset distance; or The wheel speed difference is less than the wheel speed limit, the yaw rate is less than the yaw rate limit, and the vehicle travel distance is greater than or equal to the preset distance. When the front wheel speed difference is less than the first wheel speed limit and the rear wheel speed difference is less than the second wheel speed limit, the wheel speed difference is determined to be less than the wheel speed limit. The first wheel speed limit is determined using the following formula: in, This indicates the first wheel speed limit. Indicates the speed of the left rear wheel. Indicates the speed of the right rear wheel. Indicates the rear wheel track. Indicates the front wheel track. This indicates the angle between the center of the outer front wheel and the center of the rear wheel and the center of the turn. Indicates wheelbase. Indicates the turning radius of the outer rear wheel. This indicates the vehicle's turning radius.

6. A computer-readable storage medium, characterized in that, It stores a control program for a steer-by-wire system, which, when executed by a processor, implements the control method for a steer-by-wire system according to any one of claims 1-4.

7. A steer-by-wire system, characterized in that, The system includes a memory, a processor, and a control program for a steer-by-wire system stored in the memory and executable on the processor. When the processor executes the control program for the steer-by-wire system, it implements the control method for the steer-by-wire system according to any one of claims 1-4.

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