Corner output control method, controller, system and vehicle

Abstract

The invention provides a steering angle output control method, a controller, a steer-by-wire system and a vehicle, and the method comprises the steps that vehicle state information is acquired, and the vehicle state information comprises a vehicle speed value and a steering wheel state; under the condition that the steering wheel state is a steering state, a rear wheel output rotation angle is determined based on the vehicle speed value; and controlling the turning angle of a rear wheel steering mechanism based on the rear wheel output turning angle. Therefore, the safe steering requirements under various vehicle speed working conditions can be met.

Description

Technical Field

[0001] The present application relates to the field of vehicle control technology, and in particular to a steering angle output control method, a controller, a wire-controlled steering system and a vehicle. Background Art

[0002] The technology of steer-by-wire systems is becoming increasingly mature, greatly improving the vehicle's handling performance and driving safety, especially the coordination of rear-wheel steering technology and front-wheel steering technology, which can achieve a more flexible and stable driving experience.

[0003] However, most rear wheel angle calculations and control strategies are implemented using a single dynamic model, which makes it difficult to meet the safe steering requirements of the steer-by-wire system under various vehicle speed conditions. Summary of the invention

[0004] In view of this, the present application provides a steering angle output control method, a controller, a steer-by-wire system and a vehicle, which can calculate the rear wheel output steering angle based on the vehicle speed value, thereby meeting the safety steering requirements under various vehicle speed conditions.

[0005] In a first aspect, an embodiment of the present application provides a steering angle output control method, comprising: obtaining vehicle status information, the vehicle status information comprising: a vehicle speed value and a steering wheel state; when the steering wheel state is a steering state, determining the rear wheel output angle based on the vehicle speed value; and controlling the rear wheel steering mechanism angle based on the rear wheel output angle.

[0006] In a second aspect, an embodiment of the present application provides a controller, comprising: an acquisition unit, used to acquire vehicle status information, the vehicle status information comprising: a vehicle speed value and a steering wheel state; a rear wheel angle determination unit, used to determine the rear wheel output angle based on the vehicle speed value when the steering wheel state is a steering state; and a control unit, used to control the rear wheel steering mechanism angle based on the rear wheel output angle.

[0007] In a third aspect, an embodiment of the present application provides a steer-by-wire system, comprising any controller provided in the embodiment of the present application.

[0008] In a fourth aspect, an embodiment of the present application provides a vehicle, including a steer-by-wire system provided by an embodiment of the present application.

[0009] The embodiments of the present application provide a steering angle output control method, a controller, a wire-controlled steering system and a vehicle, which can determine the rear wheel output angle according to the vehicle speed value, and control the rear wheel steering mechanism angle based on the rear wheel output angle, so as to achieve precise control and output of the rear wheel angle matching various vehicle speed conditions, so as to meet the safety steering requirements under various vehicle speed conditions, improve the steering safety, optimize the vehicle's handling and enhance the vehicle's steering stability. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] In order to more clearly illustrate the specific implementation methods of the present application or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present application. For those skilled in the art, other drawings can be obtained based on these drawings without paying any creative work.

[0011] Figure 1 A schematic structural diagram of a wire-controlled steering system provided in an embodiment of the present application is shown;

[0012] Figure 2 A schematic flow chart of a method for controlling a turning angle output provided by an embodiment of the present application is shown;

[0013] Figure 3 A schematic diagram showing the relationship between a front wheel target turning angle and a rear wheel target turning angle provided by an embodiment of the present application is shown;

[0014] Figure 4 A schematic diagram showing the relationship between a vehicle speed and a rear wheel proportional coefficient provided in an embodiment of the present application;

[0015] Figure 5 A schematic flow chart showing another method for controlling the output of a turning angle provided in an embodiment of the present application is shown;

[0016] Figure 6 A schematic diagram showing the relationship between a vehicle speed value and a rear wheel turning angle limit value provided by the present application

[0017] Figure 7 A schematic diagram showing the structure of a controller provided in an embodiment of the present application is shown;

[0018] Figure 8 A schematic structural diagram of a vehicle provided in an embodiment of the present application is shown. DETAILED DESCRIPTION

[0019] In order to make the above and other features and advantages of the present application more clear, the present application is further described below in conjunction with the accompanying drawings. It should be understood that the specific embodiments given herein are for the purpose of explaining to those skilled in the art and are only exemplary and not restrictive.

[0020] In the following description, many specific details are set forth to provide a thorough understanding of the present application. However, it is apparent to those skilled in the art that specific details need not be adopted to practice the present application. In other cases, well-known steps or operations are not described in detail to avoid blurring the present application.

[0021] When the vehicle is traveling at a low speed or the steering wheel is turned in place, the existing wire-controlled steering system controls the rear wheels to turn in the opposite direction of the front wheels, that is, when the front wheels turn left, the rear wheels turn right, and when the front wheels turn right, the rear wheels turn left. When the vehicle is moving at a high speed and the steering wheel is turned, the rear wheels are controlled to turn in the same direction as the front wheels, that is, when the front wheels turn left, the rear wheels turn left, and when the front wheels turn right, the rear wheels turn right. Although the existing wire-controlled steering system can reduce the turning radius when the vehicle is turning at a low speed and increase the turning radius when turning at a high speed, there are several problems:

[0022] 1. The inventors have found through long-term research that when parking or driving at low speed, the purpose of vehicle steering can be achieved by steering the front wheels, while the existing wire-controlled steering system needs to control the rear wheels to steer in the opposite direction to the front wheels, thereby increasing the system burden.

[0023] 2. The steering operation of the existing wire-controlled steering system under various vehicle speed conditions causes large changes in the rear wheels, and there is no restriction on the steering angle of the rear wheels, resulting in rear suspension instability, thereby affecting the safety and stability of the vehicle.

[0024] In view of this, the inventors propose a steering angle output control method, a controller, a steering system and a vehicle, which can adaptively adjust the output steering angle of the rear-wheel steering structure according to various vehicle speeds, thereby reducing the system burden, reducing system power consumption, reducing instability caused by excessive steering of the rear wheels, and improving the safety and stability of vehicle driving.

[0025] On the one hand, an embodiment of the present application provides a steer-by-wire system. Figure 1 A schematic diagram of the structure of a wire-controlled steering system provided in an embodiment of the present application is shown as follows: Figure 1 As shown, the steer-by-wire system 10 may include a controller 11 , a first motor drive unit 12 , a second motor drive unit 13 , a first six-phase motor 14 , a second six-phase motor 15 , a front-wheel steering mechanism 16 , and a rear-wheel steering mechanism 17 .

[0026] Among them, the controller 11 can implement any one of the steering angle output control methods provided in the embodiments of the present application. Specifically, the controller 11 can determine the rear wheel output steering angle corresponding to the rear wheel steering mechanism and the front wheel steering angle output value corresponding to the front wheel steering mechanism according to the vehicle state information. The controller 11 is connected to the first motor drive unit 12 and the second motor drive unit 13 via a communication bus. The controller sends the front wheel steering angle output value to the first motor drive unit 12 and sends the rear wheel output steering angle to the second motor drive unit 13 via the communication bus.

[0027] The first motor drive unit 12 is used to drive the first six-phase motor 14 so that the front wheel steering mechanism 16 adjusts the angle according to the output value of the front wheel steering angle, and the second motor drive unit 13 is used to drive the second six-phase motor 15 so that the rear wheel steering mechanism 17 adjusts the angle according to the output angle of the rear wheel. In this way, the wire control steering system can achieve accurate control and output of the front wheel steering angle and the rear wheel steering angle matching various vehicle speed conditions, improve the safety of steering, optimize the vehicle's maneuverability, and enhance the stability of vehicle steering.

[0028] Another aspect of the present application provides a method for controlling a rotation angle output, which is applied to Figure 1 In the controller 11 shown, Figure 2 A schematic flow chart of a method for controlling a turning angle output provided by an embodiment of the present application is shown as follows: Figure 2 As shown, the turning angle output control method may include the following steps.

[0029] S21, obtaining vehicle status information.

[0030] The vehicle status information involved in this application refers to information about the current running state of the vehicle, which may include but is not limited to the vehicle speed value and the steering wheel state. Among them, the vehicle speed value can reflect the speed state of the vehicle. The speed state of the vehicle can include a low speed state, a medium speed state, and a high speed state.

[0031] In one embodiment of the present application, the controller 11 can obtain vehicle status information through a sensor system built into the vehicle, such as obtaining the current vehicle speed value through a vehicle speed sensor, and detecting the angle of the direction through a steering wheel angle sensor or a steering torque sensor to determine whether the steering wheel is in a steering state.

[0032] S22, when the steering wheel state is the turning state, determining the rear wheel output angle based on the vehicle speed value.

[0033] In one embodiment of the present application, the steering wheel state may include a steering state and a non-steering state. The steering state may indicate that the vehicle needs to perform a steering operation. The rear wheel output angle includes not only the angle size but also the angle direction.

[0034] In one embodiment of the present application, when the controller determines that the steering wheel state is a steering state, it can match the corresponding rear wheel angle output control strategy according to the vehicle speed value, and calculate the rear wheel output angle corresponding to the vehicle speed value according to the corresponding rear wheel angle output strategy.

[0035] S23, controlling the rear wheel steering mechanism angle based on the rear wheel output angle.

[0036] In one embodiment of the present application, the controller 11 sends the rear wheel output angle to the second drive unit 13, and the second drive unit 13 drives the second six-phase motor 15 so that the second six-phase motor 15 controls the rear wheel steering mechanism 17 to adjust the angle according to the rear wheel output angle.

[0037] In the above embodiment, the rear wheel output angle is determined by the vehicle speed value, and the rear wheel steering mechanism angle is controlled based on the rear wheel output angle, so that the rear wheel angle can be accurately controlled and output to match various vehicle speed conditions, meet the safety steering requirements under various vehicle speed conditions, improve the safety of steering, optimize the vehicle's handling, and enhance the stability of vehicle steering.

[0038] In some embodiments, S22, when the steering wheel state is a turning state, determining the rear wheel output angle based on the vehicle speed value, including: when the steering wheel state is a turning state, comparing the vehicle speed value with a first threshold; when the vehicle speed value is not greater than the first threshold, determining that the rear wheel output angle is 0.

[0039] The first threshold involved in the embodiment of the present application can be set according to vehicle performance and safety standards, and is a threshold used to determine whether the vehicle is in a low-speed state.

[0040] The vehicle speed value being not greater than the first threshold value may indicate that the current vehicle speed is relatively low and the vehicle speed state is a low speed state, that is, the vehicle may be in a low speed driving state, a starting state, or a parking state.

[0041] In one embodiment of the present application, the controller can determine whether the rear wheel steering angle output control strategy is a low-speed steering angle output control strategy based on a comparison result between the current vehicle speed value and the first threshold value, wherein the low-speed steering angle output control strategy is that the rear wheel output steering angle is 0.

[0042] When the rear wheel steering angle output control strategy is the low-speed steering angle output control strategy, the rear wheel output steering angle is determined to be 0 based on the low-speed steering angle output control strategy.

[0043] In this way, by determining the rear wheel output angle to be 0, the steer-by-wire mechanism can control the rear wheel steering mechanism not to adjust the angle when the vehicle is in a low-speed, parking or starting state, thereby not performing opposite steering to the front wheel steering mechanism and completing the steering operation, reducing the system burden and improving the low-speed steering efficiency.

[0044] In some embodiments, when the steering wheel state is a turning state, after comparing the vehicle speed value with a first threshold value, S22, when the steering wheel state is a turning state, determining the rear wheel output angle based on the vehicle speed value may also include: when the vehicle speed value is greater than the first threshold value, comparing the vehicle speed value with a second threshold value; when the vehicle speed value is less than the second threshold value, calculating the first target angle and the second target angle of the rear-wheel steering mechanism; determining the rear wheel output angle based on a preset arbitration strategy and the first target angle and the second target angle.

[0045] The second threshold involved in the embodiment of the present application can be set according to the vehicle performance and safety standards, and is used to determine whether the speed state of the vehicle is a medium-speed state or a high-speed state. Wherein, the second threshold is greater than the first threshold. Optionally, the second threshold is at least ten times the first threshold. In an embodiment of the present application, the first threshold can be 5 kilometers per hour, and the second threshold can be 50 kilometers per hour.

[0046] If the vehicle speed value is greater than the first threshold, it can indicate that the vehicle speed state is in a medium speed state or a high speed state. If the vehicle speed value is less than the second threshold, it can indicate that the vehicle speed state is in a medium speed state.

[0047] The first target turning angle and the second target turning angle of the rear wheel steering mechanism involved in the embodiment of the present application can be obtained according to different system control principles. For example, the first target turning angle can be obtained according to the synergistic relationship between the front wheel steering mechanism and the rear wheel steering mechanism, and the second target turning angle can be obtained according to the transition response compensation principle.

[0048] In one embodiment of the present application, the controller determines whether the vehicle is in a medium speed state by comparing the vehicle speed value with the second threshold value. When the controller determines that the vehicle is in a medium speed state, a medium speed turning angle output strategy is adopted to determine the output turning angle of the rear wheel. The medium speed turning angle output strategy is to first obtain a first target turning angle and a second target turning angle of the rear wheel steering mechanism based on different turning angle calculation methods, and then fuse the first target turning angle and the second target turning angle according to a preset arbitration strategy to determine the output turning angle of the rear wheel.

[0049] The preset arbitration strategy may involve decision logic such as comparison and summation of two target corners and selection of the maximum value.

[0050] It is understandable that the vehicle speed value may be compared with the first threshold value and the second threshold value at the same time, and the rear wheel output angle may be further determined based on different comparison results.

[0051] In the above embodiment, the vehicle state can be divided more finely through dual threshold judgment, which is convenient for more precise control of the steering angle of the rear-wheel steering mechanism. And through the preset arbitration strategy, the steering angle of the rear-wheel steering mechanism in the medium-speed stage can be dynamically optimized, so that the steering angle of the rear-wheel steering mechanism in the medium-speed stage changes continuously, reducing the occurrence of large changes in the steering angle, and improving driving safety and stability.

[0052] In some embodiments, the steering angle output control method may further include acquiring vehicle performance parameters, and the corresponding first target steering angle of the rear-wheel steering mechanism may be obtained based on the vehicle state information and the vehicle performance parameters.

[0053] Specifically, the vehicle state information may also include a steering wheel angle. The step of calculating the first target angle of the rear wheel steering mechanism may include: obtaining a front wheel target angle based on the steering wheel angle in the vehicle state information and a transmission ratio of the steering system in the vehicle performance parameters; and obtaining a first target angle based on the vehicle speed value and the front wheel target angle.

[0054] In one embodiment, the calculation formula of the front wheel target turning angle can be expressed as:

[0055]

[0056] Among them, δf is the target turning angle of the front wheel, δsw is the steering wheel angle, and is is the transmission ratio of the steering system.

[0057] In one embodiment of the present application, the controller pre-stores a table of the relationship between the front wheel target angle and the rear wheel target angle and a table of the relationship between the vehicle speed and the rear wheel ratio. The table of the relationship between the front wheel target angle and the rear wheel target angle can reflect the functional relationship between the front wheel target angle and the rear vehicle target angle. The table of the relationship between the vehicle speed and the rear wheel ratio can reflect the relationship between the vehicle speed value and the rear wheel ratio coefficient. The rear wheel ratio coefficient is the ratio of the first target angle to the rear wheel target angle.

[0058] The controller first searches for the rear wheel target turning angle corresponding to the calculated front wheel target turning angle from the front wheel target turning angle and rear wheel target turning angle relationship table. Then, the rear wheel proportional coefficient corresponding to the vehicle speed value is searched from the vehicle speed and rear wheel proportional relationship table. Finally, the rear wheel proportional coefficient is multiplied by the rear wheel target turning angle to obtain the first target turning angle.

[0059] The first target angle The calculation formula can be:

[0060]

[0061] Among them, L is the rear wheel proportional coefficient obtained by looking up the table, is the target turning angle of the rear wheel obtained by looking up the table.

[0062] Figure 3 FIG. 1 is a schematic diagram showing the relationship between a front wheel target turning angle and a rear wheel target turning angle provided by an embodiment of the present application. Figure 3 As shown, when the front wheel target turning angle is not greater than the first turning angle threshold δ 1 When the target turning angle of the rear wheel is 0, the target turning angle of the front wheel is greater than the first turning angle threshold δ 1 When , the target turning angle of the rear wheel is directly proportional to the target turning angle of the front wheel.

[0063] Figure 4 A schematic diagram showing the relationship between vehicle speed and rear wheel proportional coefficient provided by an embodiment of the present application is shown. Figure 4 As shown, when the vehicle speed value is less than the first vehicle speed threshold v1, the rear wheel proportional coefficient is 0. When the vehicle speed value is not less than the first vehicle speed threshold v1 and less than the second vehicle speed threshold v 2 When the vehicle speed is not less than the second speed threshold v2 and less than the third speed threshold v3, the rear wheel proportional coefficient remains unchanged. When the vehicle speed is not less than the third speed threshold v3 and less than the fourth speed threshold v 4 When the vehicle speed value is not less than the fourth vehicle speed threshold value v4, the rear wheel proportional coefficient is 0.

[0064] It should be noted that the specific values ​​of the first turning angle threshold, the first vehicle speed threshold, the second vehicle speed threshold, the third vehicle speed threshold and the fourth vehicle speed threshold can be determined based on calibration tests.

[0065] In some embodiments, the second target steering angle of the rear-wheel steering mechanism may be a target steering angle of the rear wheels applied during the transition response compensation process, and may be obtained based on vehicle state information and vehicle performance parameters.

[0066] In one embodiment, the second target turning angle can be determined according to the relationship between the rear wheel target turning angle and the front wheel target turning angle during the steady-state control process. Specifically, the turning angle proportional coefficient can be obtained based on the differential equation of motion of the vehicle, and the turning angle proportional coefficient is multiplied by the front wheel target turning angle to obtain the second target turning angle.

[0067] The differential equation of motion for the car can be expressed as

[0068]

[0069] Among them, β represents the sideslip angle of the center of mass, ωr can represent the yaw rate, δf can represent the target turning angle of the front wheel, and δr 1 can represent the first target turning angle, a can represent the distance from the center of mass to the front axle, b can represent the distance from the center of mass to the rear axle, u can represent the forward speed, v can represent the lateral speed, Iz can represent the moment of inertia of the vehicle around the z-axis, k 1 It can be expressed as the front tire cornering stiffness, k2 It can represent the cornering stiffness of the rear tire, and m can represent the total vehicle mass.

[0070] make β=0, substitute into formula (3) and eliminate ωr, and we can get the angle ratio coefficient k between the second target angle and the front wheel target angle: 0 . Rotation angle proportionality factor k 0 It can be expressed as:

[0071]

[0072] Second target corner It can be expressed as:

[0073]

[0074] Wherein, δf is the target turning angle of the front wheel calculated according to formula (1).

[0075] Since the first target turning angle and the second target turning angle are calculated based on different vehicle control principles, they can represent different motion characteristics of the rear-wheel steering mechanism of the steering system. Therefore, the first target turning angle and the second target turning angle are different in direction and size, so a preset arbitration strategy is required to help determine the final rear-wheel output angle.

[0076] In some embodiments, the rear wheel output angle is determined based on a preset arbitration strategy and a first target angle and a second target angle, including: determining whether the directions of the first target angle and the second target angle are the same; if the directions are the same, taking the larger value of the first target angle and the second target angle as the rear wheel output angle; if the directions are opposite, taking the sum of the first target angle and the second target angle as the rear wheel output angle, and the direction of the rear wheel output angle is the same as the direction of the first target angle.

[0077] In one embodiment of the present application, since the sign of the target angle indicates the direction of the target angle, for example, a positive sign indicates a left turn, and a sign indicates a right turn, or a positive sign indicates a right turn, and a sign indicates a left turn. Therefore, whether the directions of the first target angle and the second target angle are the same can be determined based on the sign of the first target angle and the sign of the second target angle, or based on whether the product of the first target angle and the second target angle is greater than 0.

[0078] When the controller determines that the sign of the first target angle is consistent with the sign of the second target angle, or the product of the first target angle and the second target angle is greater than 0, it can be determined that the direction of the first target angle is the same as the direction of the second target angle, thereby comparing the numerical values ​​of the first target angle and the second target angle, and using the larger value as the rear wheel output angle. For example, when the first target angle is greater than the second target angle, the controller uses the first target angle as the rear wheel output angle. When the first target angle is not greater than the second target angle, the controller uses the second target angle as the rear wheel output angle. In this way, it helps the rear-wheel steering mechanism to follow the movement trend of the forward steering mechanism and enhance the stability of the system.

[0079] When the controller determines that the sign of the first target angle is inconsistent with the sign of the second target angle, or the product of the first target angle and the second target angle is less than 0, it can be determined that the direction of the first target angle is different from the direction of the second target angle, so that the first target angle and the second target angle are added together to obtain the rear wheel output angle, that is, the sum of the two is used as the rear wheel output angle.

[0080] In this way, the pre-arbitration strategy can make the rear wheel output angle change continuously at medium speed, reduce the occurrence of large changes, and improve the safety and stability of the system steering. In addition, the control logic in the pre-arbitration strategy is relatively simple, and the system response speed can be improved through simple control logic.

[0081] In some embodiments, the steering angle output control method further includes using the front wheel target steering angle calculated by formula (1) as the front wheel output steering angle, and controlling the front wheel steering mechanism steering angle according to the front wheel output steering angle.

[0082] In the embodiment of the present application, the controller calculates the front wheel target angle according to formula (1) and uses it as the front wheel output angle. The controller sends the front wheel output angle to the first drive unit 12, and the first drive unit 12 drives the first six-phase motor 14, so that the first six-phase motor 14 controls the front wheel steering mechanism 16 to adjust the angle according to the front wheel output angle.

[0083] In some embodiments, when the vehicle speed value is greater than the first threshold value, after comparing the vehicle speed value with the second threshold value, S22, when the steering wheel state is the steering state, determining the rear wheel output angle based on the vehicle speed value, further comprising: when the vehicle speed value is not less than the second threshold value, when the vehicle speed value is not less than the second threshold value, determining the rear wheel output angle based on the preset maximum angle value and the direction of the front wheel target angle. Wherein, the rear wheel output angle direction is the same as the first target angle direction.

[0084] The vehicle speed value involved in the embodiment of the present application is not less than the second threshold value, which can indicate that the current vehicle speed is relatively high and the speed state of the vehicle is a high speed state.

[0085] The inventors have found that when the rear wheel mechanism and the front wheel mechanism turn in the same direction at high speed, the turning radius can be increased and the turning stability can be enhanced. Therefore, in the embodiment of the present application, the direction of the front wheel target angle can be set as the direction of the rear wheel output angle. That is, when the direction of the front wheel target angle is a left turn, the direction of the rear wheel output angle is a left turn. Or, when the direction of the front wheel target angle is a right turn, the direction of the rear wheel output angle is a right turn. In other words, the sign of the front wheel target angle is the same as the sign of the rear wheel output angle.

[0086] In one embodiment of the present application, when the controller determines that the vehicle speed value is greater than the second threshold value, the rear wheel steering angle output control strategy is determined to be a high-speed steering angle output control strategy, and the rear wheel output steering angle is determined based on the high-speed steering angle output control strategy. The high-speed steering angle output control strategy is to determine the direction of the front wheel target steering angle as the direction of the rear wheel output steering angle, and to use the preset maximum steering angle value as the value of the rear wheel output steering angle. Optionally, the preset maximum steering angle value is a positive number not greater than 20.

[0087] In the above embodiment, by presetting the maximum turning angle value to limit the rear wheel output turning angle, the rear overhang will not be greatly disengaged during high-speed driving, thereby improving the stability and safety of the steering process.

[0088] In order to further understand the steering angle output control method of the wire steering system, the embodiment of the present application provides another steering angle output control method on the other hand. Figure 5 A flow chart of another method for controlling the output of a turning angle provided in an embodiment of the present application is shown as follows: Figure 5 The turning angle output control method may include:

[0089] S51, obtain vehicle status information, jump to S52 and S59.

[0090] The vehicle status information includes the vehicle speed value and the steering wheel status.

[0091] S52, determine the speed state of the vehicle according to the vehicle speed value. If the speed state is a low speed state, jump to S53; if the speed state is a medium speed state, jump to S54. If the speed state is a high speed state, jump to S58.

[0092] When the vehicle speed value is not greater than the first threshold, the speed state is a low speed state. When the vehicle speed value is greater than the first threshold and less than the second threshold, the speed state is a medium speed state. When the vehicle speed value is not less than the second threshold, the speed state is a high speed state.

[0093] S53, determine that the rear wheel output angle value is 0, and jump to S510.

[0094] S54, obtaining the first target turning angle and the second target turning angle, and jumping to S55.

[0095] The calculation method of the first target angle and the second target angle is the same as that of the above embodiment, and will not be repeated here.

[0096] S55, comparing the directions of the first target corner and the second target corner to see if they are the same. If they are the same, jump to S56; if they are different, jump to S57.

[0097] S56: The larger value of the first target turning angle and the second target turning angle is used as the rear wheel output turning angle, and the process proceeds to S510.

[0098] S57, taking the sum of the first target turning angle and the second target turning angle as the rear wheel output turning angle, and jumping to S510.

[0099] S58, determine the rear wheel output angle based on the front wheel output angle and the preset maximum angle value, and jump to S510.

[0100] S59, determine the front wheel target angle based on the steering wheel angle and the transmission ratio of the steering system, and use the front wheel target angle as the front wheel output angle, and jump to S510.

[0101] S510, controlling a front wheel steering mechanism angle based on the front wheel output angle, and controlling a rear wheel steering mechanism angle based on the rear wheel output angle.

[0102] Among them, the steering wheel angle can be obtained from the vehicle status information, and the transmission ratio can be obtained from the vehicle performance parameters.

[0103] In the above embodiment, by limiting the rear wheel output angle at different vehicle speeds, the rear overhang can be prevented from being disengaged significantly, thereby improving the stability and safety of the steering process. In addition, by setting the rear wheel output angle to 0 at low speeds, the system burden can be reduced and the steering efficiency can be improved.

[0104] It should be noted that, after many experiments, it was found that the angle output control method provided by the present application can achieve that under different speed conditions, the rear wheel angle output value is not greater than the rear wheel angle limit value, that is, under different speed conditions, the rear wheel angle output is angle-limited. Figure 6 A schematic diagram showing the relationship between a vehicle speed value and a rear wheel turning angle limit value provided by the present application is shown as follows: Figure 6 As shown, in the low speed state, that is, the vehicle speed value is lower than the first threshold value V 5 When the rear wheel steering angle limit value is 0; in the medium speed state, that is, the vehicle speed value is not greater than the first threshold value V 5 and is less than the second threshold V 6, the rear wheel steering angle limit value is directly proportional to the vehicle speed; at high speed, that is, greater than the second threshold, the rear wheel steering angle limit value reaches the maximum.

[0105] In another aspect, the present application provides a controller, Figure 7 A schematic diagram of the structure of a controller provided in an embodiment of the present application is shown as follows: Figure 7 As shown, the controller 70 may include an acquisition unit 71 for acquiring vehicle status information, the vehicle status information including: a vehicle speed value and a steering wheel state; a rear wheel angle determination unit 72 for determining a rear wheel output angle based on the vehicle speed value when the steering wheel state is a steering state; and a control unit 73 for controlling the rear wheel steering mechanism angle based on the rear wheel output angle.

[0106] In some embodiments, the rear wheel steering angle determination unit 72 is configured to: compare the vehicle speed value with a first threshold; and determine that the rear wheel output steering angle is 0 when the vehicle speed value is not greater than the first threshold.

[0107] In some embodiments, the rear wheel steering angle determination unit 72 is also used for: when the vehicle speed value is greater than a first threshold value, comparing the vehicle speed value with a second threshold value, wherein the second threshold value is greater than the first threshold value; when the vehicle speed value is less than the second threshold value, calculating the first target steering angle of the rear wheels and the second target steering angle of the rear wheels; and determining the rear wheel output steering angle based on a preset arbitration strategy and the first target steering angle and the second target steering angle.

[0108] In some embodiments, the rear wheel turning angle determination unit 72 is also specifically used to: determine whether the directions of the first target turning angle and the second target turning angle are the same; if the directions are the same, then the larger value of the first target turning angle and the second target turning angle is used as the rear wheel output angle; if the directions are opposite, then the sum of the first target turning angle and the second target turning angle is used as the rear wheel output angle, and the direction of the rear wheel output angle is the same as the direction of the first target turning angle.

[0109] In some embodiments, the rear wheel steering angle determination unit 72 is also used to: when the vehicle speed value is not less than a second threshold value, determine the rear wheel output angle based on a preset maximum steering angle and the direction of the front wheel target steering angle, wherein the front wheel target steering angle is determined according to the steering wheel angle and the transmission ratio of the steering system.

[0110] Another aspect of the present application embodiment further provides a vehicle, Figure 8 A schematic diagram of the structure of a vehicle provided in an embodiment of the present application is shown. Figure 8 As shown, the vehicle 80 may include a steer-by-wire system 81 provided in an embodiment of the present application.

[0111] It should be understood that the specific features, operations and details described hereinabove regarding the method of the present application may also be similarly applied to the device and system of the present application, or vice versa. In addition, each step of the method of the present application described above may be performed by a corresponding component or unit of the device or system of the present application.

[0112] It should be understood that each module / unit of the device of the present application can be implemented in whole or in part by software, hardware, firmware or a combination thereof. Each module / unit can be embedded in the processor of the electronic device or independent of the processor in the form of hardware or firmware, or can be stored in the memory of the electronic device in the form of software for the processor to call to perform the operation of each module / unit. Each module / unit can be implemented as an independent component or module, or two or more modules / units can be implemented as a single component or module.

[0113] Those skilled in the art will appreciate that the method steps of the present application can be completed by instructing related hardware such as electronic devices or processors through a computer program, and the computer program can be stored in a non-temporary computer-readable storage medium, and the computer program causes the steps of the present application to be executed when it is executed. Depending on the circumstances, any reference to memory, storage or other media herein may include non-volatile or volatile memory. Examples of non-volatile memory include read-only memory (ROM), programmable ROM (PROM), electrically programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM), flash memory, magnetic tape, floppy disk, magneto-optical data storage device, optical data storage device, hard disk, solid state disk, etc. Examples of volatile memory include random access memory (RAM), external cache memory, etc.

[0114] The various technical features described above can be combined arbitrarily. Although all possible combinations of these technical features are not described, any combination of these technical features should be considered to be covered by this specification as long as there is no contradiction in such combination.

[0115] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit it. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein by equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A method for controlling an angle output, characterized in that: include: Acquiring vehicle status information, wherein the vehicle status information includes: vehicle speed value and steering wheel status; When the steering wheel state is a turning state, determining a rear wheel output angle based on the vehicle speed value; The rear wheel steering mechanism angle is controlled based on the rear wheel output angle.

2. The method according to claim 1, characterized in that When the steering wheel state is a steering state, determining the rear wheel output angle based on the vehicle speed value includes: When the steering wheel state is a turning state, comparing the vehicle speed value with a first threshold value; When the vehicle speed value is not greater than a first threshold value, the rear wheel output angle is determined to be 0.

3. The method according to claim 2, characterized in that When the steering wheel state is the steering state, after comparing the vehicle speed value with the first threshold, the method further includes: When the vehicle speed value is greater than the first threshold, comparing the vehicle speed value with a second threshold, wherein the second threshold is greater than the first threshold; When the vehicle speed value is less than the second threshold value, calculating a first target turning angle and a second target turning angle of a rear-wheel steering mechanism; The rear wheel output steering angle is determined based on a preset arbitration strategy, the first target steering angle, and the second target steering angle.

4. The method according to claim 3, characterized in that The determining the rear wheel output angle based on a preset arbitration strategy, the first target angle, and the second target angle comprises: determining whether the first target angle and the second target angle have the same direction; If the directions are the same, the larger value of the first target turning angle and the second target turning angle is used as the rear wheel output turning angle; If the directions are opposite, the sum of the first target turning angle and the second target turning angle is used as the rear wheel output turning angle, and the direction of the rear wheel output turning angle is the same as the direction of the first target turning angle.

5. The method according to claim 3, characterized in that: In the case where the vehicle speed value is greater than the first threshold, after comparing the vehicle speed value with the second threshold, the method further includes: When the vehicle speed value is not less than the second threshold, the rear wheel output angle is determined based on a preset maximum angle and a direction of a front wheel target angle, wherein the front wheel target angle is determined according to a steering wheel angle and a transmission ratio of a steering system.

6. The method according to claim 3, characterized in that The first threshold is 5, and the second threshold is 50.

7. A controller, characterized in that: include: An acquisition unit, used to acquire vehicle status information, wherein the vehicle status information includes: a vehicle speed value and a steering wheel status; a rear wheel steering angle determination unit, configured to determine a rear wheel output steering angle based on the vehicle speed value when the steering wheel state is a steering state; A control unit is used to control the rear wheel steering mechanism angle based on the rear wheel output angle.

8. The controller according to claim 7, characterized in that: The rear wheel turning angle determination unit has a function of: comparing the vehicle speed value with a first threshold; When the vehicle speed value is not greater than a first threshold value, the rear wheel output angle is determined to be 0.

9. The controller according to claim 8, characterized in that: The rear wheel turning angle determination unit is further used for: When the vehicle speed value is greater than the first threshold, comparing the vehicle speed value with a second threshold, wherein the second threshold is greater than the first threshold; When the vehicle speed value is less than the second threshold value, calculating a first target turning angle and a second target turning angle of a rear-wheel steering mechanism; The rear wheel output steering angle is determined based on a preset arbitration strategy, the first target steering angle, and the second target steering angle.

10. The controller according to claim 9, characterized in that: The rear wheel turning angle determination unit is further specifically used for: determining whether the first target angle and the second target angle have the same direction; If the directions are the same, the larger value of the first target turning angle and the second target turning angle is used as the rear wheel output turning angle; If the directions are opposite, the sum of the first target turning angle and the second target turning angle is used as the rear wheel output turning angle, and the direction of the rear wheel output turning angle is the same as the direction of the first target turning angle.

11. The controller according to claim 9, characterized in that: The rear wheel turning angle determination unit is further used for: When the vehicle speed value is not less than the second threshold value, the rear wheel output angle is determined based on the preset maximum angle and the direction of the front wheel target angle, wherein the front wheel target angle is determined according to the steering wheel angle and the transmission ratio of the steering system.

12. A steer-by-wire system, characterized in that: A controller comprising any one of claims 6 to 11.

13. A vehicle, characterized in that: Comprising the steer-by-wire system of claim 12.

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