Steering-by-wire system control method and device and steering-by-wire system

Abstract

The invention discloses a control method and device of a steer-by-wire system and the steer-by-wire system. The control method comprises the steps that current driving state information and steering wheel information of a vehicle are obtained; when it is judged that the vehicle is in the off-tracking state according to the driving state information and the steering wheel information, a steering motor of the vehicle is controlled to output off-tracking compensation torque to a steering gear according to the driving state information so as to correct the off-tracking state.

Description

Technical Field

[0001] The present application relates to the field of transportation vehicles, and more specifically to a control method and device for a steer-by-wire system, and a steer-by-wire system. Background Art

[0002] At present, more and more vehicles use steer-by-wire systems. The steer-by-wire system eliminates the mechanical connection between the steering wheel and the steering gear, obtains the steering wheel angle data through the sensor, and controls the steering motor to output the steering torque to the steering gear according to the steering wheel angle data to drive the vehicle to steer. The safety of the steer-by-wire system in the related art is poor. Summary of the invention

[0003] The present application is proposed to solve at least one of the above problems. According to the first aspect of the present application, a control method for a wire-controlled steering system is provided, the control method comprising: obtaining current driving state information and steering wheel information of a vehicle; when it is determined that the vehicle is in a deviation state according to the driving state information and the steering wheel information, according to the driving state information, controlling the steering motor of the vehicle to output a deviation compensation torque to the steering gear to reduce the deviation amount of the vehicle.

[0004] In one embodiment of the present application, determining that the vehicle is in a swerving state based on the driving state information and the steering wheel information includes: judging whether the vehicle is in a straight-ahead state or a non-straight-ahead state based on the driving state information; judging whether the driver of the vehicle has a steering intention based on the steering wheel information; and determining that the vehicle is in the swerving state when the vehicle is in the non-straight-ahead state and the driver has no steering intention.

[0005] In one embodiment of the present application, the control method further includes: when the vehicle is in the straight-ahead state and the driver has no intention to turn, or when the vehicle is in the non-straight-ahead state and the driver has an intention to turn, determining that the vehicle is not in the deviation state.

[0006] In one embodiment of the present application, obtaining the current driving status information and steering wheel information of the vehicle includes: obtaining the vehicle speed, yaw angular velocity, lateral acceleration, left steering wheel speed and right steering wheel speed of the vehicle, and using the vehicle speed, yaw angular velocity, lateral acceleration, left steering wheel speed and right steering wheel speed as the driving status information; obtaining the steering wheel angle, steering wheel angular velocity, and steering wheel torque output by the vehicle's road feel simulation motor to the vehicle's steering wheel, and using the steering wheel angle, the steering wheel angular velocity and the steering wheel torque as the steering wheel information.

[0007] In one embodiment of the present application, judging whether the vehicle is in a straight-ahead state or a non-straight-ahead state based on the driving state information includes: when the vehicle speed is greater than a preset speed, if the difference between the left steering wheel speed and the right steering wheel speed is less than a preset difference, the yaw angular velocity is less than a preset yaw angular velocity, and the lateral acceleration is less than a preset lateral acceleration, then determining that the vehicle is in the straight-ahead state; when the vehicle speed is greater than the preset speed, if the difference between the left steering wheel speed and the right steering wheel speed is not less than the preset difference, the yaw angular velocity is not less than the preset yaw angular velocity, or / and the lateral acceleration is not less than the preset lateral acceleration, then determining that the vehicle is in the non-straight-ahead state.

[0008] In one embodiment of the present application, judging whether the driver of the vehicle has a steering intention based on the steering wheel information includes: when the steering wheel angle is less than a preset angle, the steering wheel angular velocity is less than a preset steering wheel angular velocity, and the steering wheel torque is within a preset steering wheel torque range, determining that the driver has no steering intention; and when the steering wheel angle is not less than the preset angle, the steering wheel angular velocity is not less than the preset angular velocity, or / and the steering wheel torque is not within the preset steering wheel torque range, determining that the driver has a steering intention.

[0009] In one embodiment of the present application, the steering motor of the vehicle is controlled to output a deviation compensation torque to the steering gear according to the driving status information to reduce the deviation amount of the vehicle, including: determining the deviation compensation torque according to the difference between the yaw angular velocity in the driving status information and a preset yaw angular velocity; controlling the steering motor to output the deviation compensation torque to the steering gear to reduce the difference between the yaw angular velocity and the preset yaw angular velocity.

[0010] In one embodiment of the present application, the deviation compensation torque is determined based on the difference between the yaw angular velocity in the driving state information and the preset yaw angular velocity, including: taking the product of a first preset correction coefficient and the difference between the yaw angular velocity and the preset yaw angular velocity as the magnitude of the deviation compensation torque; when the absolute value of the yaw angular velocity is greater than the absolute value of the preset yaw angular velocity, the direction of the deviation compensation torque is opposite to the direction of the yaw angular velocity; when the absolute value of the yaw angular velocity is less than the absolute value of the preset yaw angular velocity, the direction of the deviation compensation torque is the same as the direction of the yaw angular velocity.

[0011] In one embodiment of the present application, the control method also includes: if the vehicle is in the deviation state, while controlling the steering motor to output the deviation compensation torque to the steering gear, the steering motor is also controlled to output the steering basic torque to the steering gear; if the vehicle is not in the deviation state, the steering motor is controlled to output the steering basic torque to the steering gear.

[0012] In one embodiment of the present application, the control method also includes: if the vehicle is in the deviation state, then according to the driving state information, controlling the road feel simulation motor of the vehicle to output a road feel compensation torque to the steering wheel of the vehicle to reduce the distance between the steering wheel torque in the steering wheel information and the preset steering wheel torque range.

[0013] In one embodiment of the present application, controlling the road feel simulation motor of the vehicle to output a road feel compensation torque to the steering wheel of the vehicle based on the driving status information includes: determining the road feel compensation torque based on the difference between the lateral acceleration in the driving status information and the preset lateral acceleration; and controlling the road feel simulation motor to output the road feel compensation torque to the steering wheel.

[0014] In one embodiment of the present application, the road feel compensation torque is determined based on the difference between the lateral acceleration in the driving status information and the preset lateral acceleration, including: taking the product of a second preset correction coefficient and the difference between the lateral acceleration and the preset lateral acceleration as the magnitude of the road feel compensation torque; when the steering wheel torque in the steering wheel information is greater than an upper limit value of a preset steering wheel torque range, determining that the direction of the road feel compensation torque is in the opposite direction to the direction of the steering wheel torque; when the steering wheel torque is less than a lower limit value of the preset steering wheel torque range, determining that the direction of the road feel compensation torque is in the same direction as the direction of the steering wheel torque.

[0015] In one embodiment of the present application, the control method also includes: if the vehicle is in the deviation state, while controlling the road feel simulation motor to output the road feel compensation torque to the steering wheel, the road feel simulation motor is also controlled to output the road feel basic torque to the steering wheel; if the vehicle is not in the deviation state, the road feel simulation motor is controlled to output the road feel basic torque to the steering wheel.

[0016] In one embodiment of the present application, the control method also includes: obtaining the steering gear output terminal position information before the vehicle travels; determining the target angle of the steering wheel based on the steering gear output terminal position information and a preset correspondence; when the steering wheel angle is different from the target angle, controlling the vehicle's road feel simulation motor to drive the steering wheel to rotate so that the steering wheel angle is equal to the target angle.

[0017] According to the second aspect of the present application, a control device for a wire-controlled steering system is also provided, the control device comprising: a storage medium and a processor, the storage medium storing a computer program executed by the processor, the computer program, when executed by the processor, enables the processor to execute any one of the above-mentioned control methods for the wire-controlled steering system.

[0018] According to a third aspect of the present application, there is also provided a steer-by-wire system, the steer-by-wire system comprising: a control device of any one of the steer-by-wire systems described above.

[0019] According to a fourth aspect of the present application, a vehicle is further provided, comprising: a control device for a steer-by-wire system as described in any one of the above, or: a steer-by-wire system as described in any one of the above.

[0020] According to the control method and device of the vehicle's steer-by-wire system and the steer-by-wire system provided in the embodiments of the present application, it is determined whether the vehicle is in a deviation state based on the vehicle's driving state information and steering wheel information; if the vehicle is in a deviation state, the vehicle's steering motor is controlled to output a deviation compensation torque to the steering gear based on the driving state information, so as to reduce the vehicle's deviation amount, which is conducive to the vehicle exiting the deviation state, thereby improving the safety of the steer-by-wire system. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings in the following description are only some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying creative labor.

[0022] Figure 1 This is a flow chart of a control method of a steer-by-wire system according to an embodiment of the present invention;

[0023] Figure 2 A schematic structural diagram of a steer-by-wire system according to an embodiment of the present invention;

[0024] Figure 3 This is a flow chart showing a method of determining whether a vehicle is in a deviation state according to an embodiment of the present invention;

[0025] Figure 4 A flow chart of the deviation torque compensation shown in one embodiment of the present invention;

[0026] Figure 5 A flow chart of road feel torque compensation according to an embodiment of the present invention;

[0027] Figure 6 A flow chart of steering wheel alignment shown in one embodiment of the present invention;

[0028] Figure 7 This is a flow chart of a control method of a steer-by-wire system according to another embodiment of the present invention;

[0029] Figure 8 A flow chart of the deviation torque compensation shown in another embodiment of the present invention;

[0030] Fig. 9 A flowchart showing road feel torque compensation according to another embodiment of the present invention;

[0031] Fig.10 The present invention is a schematic block diagram of a control device for a steer-by-wire system according to an embodiment of the present invention.

[0032] Reference numerals:

[0033] 100-Control device for steer-by-wire system

[0034] 10- Steering wheel 11- Steering column

[0035] 12-Road feel simulation motor 20-Steering motor

[0036] 21- reducer 22- steering gear

[0037] 31-left steering wheel 32-right steering wheel DETAILED DESCRIPTION

[0038] In order to make the purpose, technical scheme and advantages of the present invention more obvious, the exemplary embodiments according to the present invention will be described in detail with reference to the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments of the present invention, and it should be understood that the present invention is not limited to the exemplary embodiments described herein. Based on the embodiments of the present invention described in the present invention, all other embodiments obtained by those skilled in the art without creative work should fall within the protection scope of the present invention.

[0039] In the following description, a large number of specific details are provided to provide a more thorough understanding of the present invention. However, it is apparent to those skilled in the art that the present invention can be implemented without one or more of these details. In other examples, in order to avoid confusion with the present invention, some technical features well known in the art are not described.

[0040] It should be understood that the present invention can be implemented in different forms and should not be interpreted as limited to the embodiments set forth herein. On the contrary, these embodiments are provided to make the disclosure thorough and complete and to fully convey the scope of the present invention to those skilled in the art.

[0041] The purpose of the terms used herein is only to describe specific embodiments and is not intended to be limiting of the present invention. When used herein, the singular forms "one", "an" and "said / the" are also intended to include plural forms, unless the context clearly indicates otherwise. It should also be understood that the terms "consisting of" and / or "comprising", when used in this specification, confirm the presence of the features, integers, steps, operations, elements and / or parts, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, parts and / or groups. When used herein, the term "and / or" includes any and all combinations of the relevant listed items.

[0042] The deviation compensation method in the related art determines the compensation torque output to the steering gear based on the steering wheel torque. However, the deviation compensation method is only applicable to EPS steering systems with mechanical connection, and is not applicable to steer-by-wire systems. The reason is that the steering wheel torque in the steer-by-wire system is provided by a road sense simulation motor. Directly using the deviation compensation method in the related art has the risk of misjudgment, which leads to abnormal deviation compensation function, affects the driving operation feel, and even provides abnormal compensation torque, resulting in accelerated deviation safety risks, resulting in poor safety of the steer-by-wire system. In order to solve at least some of the problems in the related art, the present invention shown below is proposed.

[0043] In order to fully understand the present invention, a detailed structure will be proposed in the following description to illustrate the technical solution proposed by the present invention. The optional embodiments of the present invention are described in detail as follows, but in addition to these detailed descriptions, the present invention may also have other implementations.

[0044] Some embodiments of the present invention are described in detail below in conjunction with the accompanying drawings. In the absence of conflict, the following embodiments and features in the embodiments can be combined with each other.

[0045] First, an application scenario of the control method of the wire-controlled steering system illustrated in the example of the present application is introduced. The control method of the wire-controlled steering system is applied to a vehicle with a wire-controlled steering system, and the vehicle is driven to steer by the wire-controlled steering system.

[0046] refer to Figure 1 and Figure 2 , an embodiment of the present application provides a control method for a wire-controlled steering system, the control method comprising:

[0047] Step 1: Obtain the vehicle's current driving status information and steering wheel 10 information;

[0048] Step 2: When it is determined that the vehicle is in a deviation state based on the driving state information and the steering wheel 10 information, the steering motor 20 of the vehicle is controlled to output a deviation compensation torque to the steering gear 22 based on the driving state information to reduce the deviation amount of the vehicle.

[0049] In the above scheme, whether the vehicle is in a deviation state is determined based on the vehicle's driving state information and the steering wheel 10 information; if the vehicle is in a deviation state, the vehicle's steering motor 20 is controlled to output a deviation compensation torque to the steering gear 22 based on the driving state information to reduce the deviation amount of the vehicle, which is conducive to the vehicle exiting the deviation state, thereby improving the safety of the wire control steering system. The above steps are described in detail below with reference to the accompanying drawings.

[0050] First, refer to Figure 1 and Figure 2 , obtain the current driving state information of the vehicle and the steering wheel 10 information. The driving state information refers to the information representing the driving state of the vehicle. The driving state information may include vehicle speed, wheel speed, yaw angular velocity, lateral acceleration, longitudinal acceleration, etc.

[0051] Exemplarily, obtaining the current driving state information of the vehicle may include: obtaining the vehicle speed, yaw rate, lateral acceleration, the wheel speed of the left steering wheel 31 and the wheel speed of the right steering wheel 32 of the vehicle, and using the vehicle speed, yaw rate, lateral acceleration, the wheel speed of the left steering wheel 31 and the wheel speed of the right steering wheel 32 as the driving state information. The lateral acceleration refers to the acceleration in the lateral direction of the vehicle. The left steering wheel 31 and the right steering wheel 32 are steering wheels connected to the same steering gear 22. For example, the vehicle may be a front steering system, and the left steering wheel 31 and the right steering wheel 32 of the vehicle are the left front wheel and the right front wheel of the vehicle, respectively. Exemplarily, the vehicle may be a rear steering system, and the left steering wheel 31 and the right steering wheel 32 of the vehicle are the left rear wheel and the right rear wheel of the vehicle, respectively.

[0052] The steering wheel 10 information may be information such as the steering wheel 10 angle, the steering wheel 10 angular velocity, the steering wheel 10 torque, etc. Exemplarily, obtaining the current steering wheel 10 information of the vehicle may include: obtaining the steering wheel 10 angle, the steering wheel 10 angular velocity, and the steering wheel 10 torque output by the vehicle's road sense simulation motor 12 to the vehicle's steering wheel 10, and using the steering wheel 10 angle, the steering wheel 10 angular velocity, and the steering wheel 10 torque as the steering wheel 10 information.

[0053] Exemplarily, the current driving state information of the vehicle and the steering wheel 10 information may be periodically acquired. For example, the current driving state information of the vehicle and the steering wheel 10 information may be acquired once every 1 second, 2 seconds, 3 seconds, 5 seconds, etc.

[0054] Next, refer to Figure 1 to Figure 3 According to the driving state information and the steering wheel 10 information, it is determined whether the vehicle is in a deviation state. Specifically, a variety of methods can be used. Several methods are introduced as follows.

[0055] Exemplary, reference Figure 1 to Figure 3 When judging whether the vehicle is in a deviation state according to the driving state information and the steering wheel 10 information, it is possible to judge whether the vehicle is in a straight-moving state or a non-straight-moving state according to the driving state information; and to judge whether the driver of the vehicle has a steering intention according to the steering wheel 10 information. When the above judgment result is: the vehicle is in a non-straight-moving state and the driver has no steering intention, it can be determined that the vehicle is in a deviation state. That is, only when the vehicle is in a non-straight-moving state and the driver has no steering intention, the deviation compensation is performed on the vehicle.

[0056] Among them, reference Figure 1 to Figure 3 When judging whether the vehicle is in a straight-moving state or a non-straight-moving state according to the driving state information, it is specifically related to the type of driving state information, and different driving state information can adopt different methods. The following takes the vehicle speed, yaw angular velocity, lateral acceleration, the wheel speed of the left steering wheel 31 and the wheel speed of the right steering wheel 32 as driving state information as an example to introduce several methods by way of example.

[0057] Exemplarily, when judging whether the vehicle is in a straight-ahead state or a non-straight-ahead state according to the driving state information, it may include: when the vehicle speed is greater than a preset speed (for example, the preset speed may be defined as V1), if the difference between the wheel speed of the left steering wheel 31 and the wheel speed of the right steering wheel 32 is less than a preset difference (for example, the preset difference may be defined as θ1), the yaw rate is less than a preset yaw rate (for example, the preset yaw rate may be defined as w1), and the lateral acceleration is less than a preset lateral acceleration (for example, the preset lateral acceleration may be defined as a1), then it is determined that the vehicle is in a straight-ahead state. That is, when the vehicle speed is greater than the preset speed, the following conditions need to be met at the same time to determine that the vehicle is in a straight-ahead state: the difference between the wheel speed of the left steering wheel 31 and the wheel speed of the right steering wheel 32 is less than a preset difference, the yaw rate is less than a preset yaw rate, and the lateral acceleration is less than a preset lateral acceleration. This eliminates the misjudgment when the vehicle speed is too low, and combines multiple indicators to improve the accuracy of judging whether the vehicle is in a straight-ahead state.

[0058] Exemplarily, when judging whether the vehicle is in a straight-ahead state or a non-straight-ahead state according to the driving state information, it may also include: when the vehicle speed is greater than the preset speed, if the difference between the wheel speed of the left steering wheel 31 and the wheel speed of the right steering wheel 32 is not less than the preset difference, the yaw angular velocity is not less than the preset yaw angular velocity, or / and the lateral acceleration is not less than the preset lateral acceleration, then it is determined that the vehicle is in a non-straight-ahead state. That is, when the vehicle speed is greater than the preset speed, if at least one of the following conditions is met, it can be determined that the vehicle is in a non-straight-ahead state: the difference between the wheel speed of the left steering wheel 31 and the wheel speed of the right steering wheel 32 is less than the preset difference, the yaw angular velocity is less than the preset yaw angular velocity, and the lateral acceleration is less than the preset lateral acceleration. This is to eliminate the misjudgment when the vehicle speed is too low, and at the same time combine multiple indicators to improve the accuracy of judging whether the vehicle is in a straight-ahead state.

[0059] During application, the vehicle may be determined to be in a non-straight-moving state because only one of the above conditions is satisfied. For example, the vehicle may be determined to be in a non-straight-moving state because the difference between the wheel speed of the left steering wheel 31 and the wheel speed of the right steering wheel 32 is not less than a preset difference, the yaw angular velocity is not less than a preset yaw angular velocity, or the lateral acceleration is not less than a preset lateral acceleration.

[0060] Exemplarily, the vehicle may be determined to be in a non-straight state because it only meets the above two conditions. For example, the vehicle may be determined to be in a non-straight state because it meets: the difference between the wheel speed of the left steering wheel 31 and the wheel speed of the right steering wheel 32 is not less than the preset difference, and the yaw angular velocity is not less than the preset yaw angular velocity, but does not meet the lateral acceleration is not less than the preset lateral acceleration. Alternatively, the vehicle may be determined to be in a non-straight state because it meets: the difference between the wheel speed of the left steering wheel 31 and the wheel speed of the right steering wheel 32 is not less than the preset difference, and the lateral acceleration is not less than the preset lateral acceleration, but does not meet the yaw angular velocity is not less than the preset yaw angular velocity. Alternatively, the vehicle may be determined to be in a non-straight state because it meets: the yaw angular velocity is not less than the preset yaw angular velocity, and the lateral acceleration is not less than the preset lateral acceleration, but does not meet the difference between the wheel speed of the left steering wheel 31 and the wheel speed of the right steering wheel 32 is not less than the preset difference.

[0061] For example, the vehicle may be determined to be in a non-execution state because the above three conditions are met. That is, the vehicle may be determined to be in a non-straight-ahead state because the difference between the wheel speed of the left steering wheel 31 and the wheel speed of the right steering wheel 32 is not less than a preset difference, the yaw angular velocity is not less than a preset yaw angular velocity, and the lateral acceleration is not less than a preset lateral acceleration.

[0062] In addition, when judging whether the driver of the vehicle has a steering intention based on the steering wheel 10 information, it is specifically related to the type of the steering wheel 10 information, and different methods can be used for different steering wheel 10 information. The following takes the steering wheel 10 angle, steering wheel 10 angular velocity and steering wheel 10 torque as the steering wheel 10 information as an example to introduce several methods by way of example.

[0063] Exemplarily, when judging whether the driver of the vehicle has a turning intention based on the steering wheel 10 information, it may include: when the steering wheel 10 angle is less than a preset angle (for example, the preset angle can be defined as α1), the steering wheel 10 angular velocity is less than a preset steering wheel 10 angular velocity (for example, the preset steering wheel 10 angular velocity can be defined as β), and the steering wheel 10 torque (for example, the steering wheel 10 torque can be defined as T) is within a preset steering wheel 10 torque range (for example, the preset steering wheel 10 torque range can be defined as [Tmin, Tmax]), it is determined that the driver has no turning intention. That is, the following conditions need to be met at the same time to determine that the driver has no turning intention: the steering wheel 10 angle is less than the preset angle, the steering wheel 10 angular velocity is less than the preset steering wheel 10 angular velocity, and the steering wheel 10 torque is within the preset steering wheel 10 torque range. The accuracy of judging whether the driver of the vehicle has a turning intention is improved by using multiple indicators.

[0064] Exemplarily, when judging whether the driver of the vehicle has a steering intention based on the information of the steering wheel 10, it may also include: when the steering wheel 10 angle is not less than the preset angle, the steering wheel 10 angular velocity is not less than the preset angular velocity, or / and the steering wheel 10 torque is not within the preset steering wheel 10 torque range, it is determined that the driver has a steering intention. That is, when the steering wheel 10 angle is greater than the preset angle, it can be determined that the driver has a steering intention if at least one of the following two conditions is met: the steering wheel 10 angular velocity is not less than the preset angular velocity, and the steering wheel 10 torque is not within the preset steering wheel 10 torque range. If the steering wheel 10 angle is less than the preset angle, it can be determined that the driver of the vehicle has no steering intention.

[0065] During application, the vehicle may be determined as having a steering intention by the driver because only one of the above conditions is met. For example, the vehicle may determine that the driver has a steering intention because the steering wheel 10 angle is greater than the preset angle, the steering wheel 10 angular velocity is not less than the preset angular velocity, or the steering wheel 10 torque is not within the preset steering wheel 10 torque range. For example, the vehicle may determine that the driver has a steering intention because the steering wheel 10 angle is greater than the preset angle, the steering wheel 10 angular velocity is not less than the preset angular velocity, and the steering wheel 10 torque is not within the preset steering wheel 10 torque range.

[0066] Exemplary, reference Figure 1 to Figure 3 , judging whether the vehicle is in a state of deviation based on the driving state information and the steering wheel 10 information, may also include: when the vehicle is in a straight state and the driver has no intention to turn, or the vehicle is in a non-straight state and the driver has an intention to turn, determining that the vehicle is not in a state of deviation. Specifically, if the judgment result is: the vehicle is in a straight state and the driver has no intention to turn, or the vehicle is in a non-straight state and the driver has an intention to turn, then it is determined that the vehicle is not in a state of deviation. That is, when the vehicle is in a non-straight state and the driver has an intention to turn, it is assumed that the vehicle is not in a state of deviation, and no deviation compensation is performed on the vehicle. When the vehicle is in a straight state and the driver has no intention to turn, the vehicle is often not in a state of deviation, and there is no need to compensate for the deviation of the vehicle.

[0067] Next, refer to Figure 1 to Figure 4 ,as well as Figure 8If the vehicle is in a state of deviation, the steering motor 20 of the vehicle is controlled to output a deviation compensation torque to the steering gear 22 according to the driving state information to reduce the deviation amount of the vehicle. In the related art, in the wire control steering system, during the driving process of the vehicle, it is necessary to control the steering motor 20 to output a steering basic torque to the steering gear 22 according to the information of the steering wheel 10, so as to provide steering feedback for the information of the steering wheel 10. However, when the vehicle is in a state of deviation, the present application controls the steering motor 20 of the vehicle to output a deviation compensation torque to the steering gear 22 in addition to controlling the steering motor 20 to output a steering basic torque to the steering gear 22, so as to compensate for the steering basic torque output by the steering motor 20 to the steering gear 22, thereby reducing the deviation amount of the vehicle, which is conducive to the vehicle exiting the deviation state, thereby improving the safety of the wire control steering system.

[0068] In the process of controlling the steering motor 20 of the vehicle to output the deviation compensation torque to the steering gear 22 according to the driving state information to reduce the deviation amount of the vehicle, various methods may be adopted, and several methods are introduced as examples below.

[0069] Exemplary, reference Figure 1 to Figure 4 ,as well as Figure 8 In the process of controlling the steering motor 20 of the vehicle to output the deviation compensation torque to the steering gear 22 according to the driving state information to reduce the deviation amount of the vehicle, the deviation compensation torque can be first determined according to the difference between the yaw velocity in the driving state information and the preset yaw velocity; then, the steering motor 20 is controlled to output the deviation compensation torque to the steering gear 22 to reduce the difference between the yaw velocity and the preset yaw velocity. That is, at this time, the deviation amount of the vehicle is reflected by the difference between the yaw velocity and the preset yaw velocity, and the steering motor 20 can be controlled to output the deviation compensation torque to the steering gear 22 to reduce the difference between the yaw velocity and the preset yaw velocity, thereby reducing the deviation amount of the vehicle. At this time, the magnitude and direction of the deviation compensation torque can be determined according to the relative magnitude of the difference between the yaw velocity and the preset yaw velocity, so that when the steering motor 20 is controlled to output the deviation compensation torque to the steering gear 22, the difference between the yaw velocity and the preset yaw velocity can be reduced.

[0070] For example, in the process of determining the deviation compensation torque according to the difference between the yaw rate in the driving state information and the preset yaw rate, the product of the first preset correction coefficient and the difference between the yaw rate and the preset yaw rate can be used as the magnitude of the deviation compensation torque, so that the deviation compensation torque and the difference between the yaw rate and the preset yaw rate are linearly positively correlated. When determining the direction of the deviation compensation torque, it is specifically related to the magnitude relationship between the absolute value of the yaw rate and the absolute value of the preset yaw rate.

[0071] Specifically, when the absolute value of the yaw angular velocity is greater than the absolute value of the preset yaw angular velocity, the direction of the deviation compensation torque is opposite to the direction of the yaw angular velocity, that is, the direction of the deviation compensation torque at this time is opposite to the direction of the yaw angular velocity, so that when the steering motor 20 is controlled to output the deviation compensation torque to the steering gear 22, the difference between the yaw angular velocity and the preset yaw angular velocity can be reduced.

[0072] When the absolute value of the yaw angular velocity is less than the absolute value of the preset yaw angular velocity, the direction of the deviation compensation torque is the same as the direction of the yaw angular velocity, that is, the direction of the deviation compensation torque at this time is the same as the direction of the yaw angular velocity, so that when the steering motor 20 is controlled to output the deviation compensation torque to the steering gear 22, the difference between the yaw angular velocity and the preset yaw angular velocity can be reduced.

[0073] Of course, according to the deviation state shown above: the driver has no intention to turn, and the vehicle is not in a straight-ahead state. Since the driver has no intention to turn, the preset yaw rate is equal to zero. There will not be a situation where the absolute value of the yaw rate is less than the absolute value of the preset yaw rate. If other deviation state judgment methods are used, the preset yaw rate may not be zero, so as to perform the above direction judgment.

[0074] Exemplarily, the deviation compensation torque (which can be defined as T2) is proportional to the difference △ω between the yaw rate and the preset yaw rate, and the calculation formula is: T2 = λ*△ω. Among them, the difference △ω between the yaw rate and the preset yaw rate is the difference between the current yaw rate ω of the vehicle and the preset yaw rate ω1; λ is the first preset correction coefficient, which needs to be calibrated according to the specific vehicle model. The deviation compensation torque T2 input by the steering motor 20 to the steering gear 22 is used to correct the deviation of the vehicle to reduce the difference △ω between the yaw rate and the preset yaw rate. The deviation compensation torque T2 decreases linearly with the decrease of the difference △ω between the yaw rate and the preset yaw rate, until the yaw rate ω is equal to the preset yaw rate ω1, and the deviation compensation torque exits, completing the vehicle deviation correction, helping the deviated vehicle to resume straight driving, and improving the safety of driving operation.

[0075] Exemplary, reference Figure 1 to Figure 4 ,as well as Figure 8 The control method may further include: if the vehicle is in a deviation state, while controlling the steering motor 20 to output a deviation compensation torque to the steering gear 22 , the steering motor 20 is also controlled to output a steering basic torque to the steering gear 22 .

[0076] Exemplary, reference Figure 1 to Figure 4 ,as well as Figure 8 The control method may further include: if the vehicle is not in a deviation state, controlling the steering motor 20 to output a basic steering torque to the steering gear 22 .

[0077] It should be explained that, during the deviation compensation process of the vehicle, the optimal deviation compensation termination method is: controlling the steering motor 20 of the vehicle to output the deviation compensation torque to the steering gear 22 until the deviation amount of the vehicle is reduced to zero, and then exiting the deviation compensation process. Of course, during the deviation compensation process of the vehicle, the above-mentioned vehicle deviation state check is also performed. If it is determined that the vehicle is not in the deviation state due to the driver's intention to turn, the deviation compensation process is directly exited, and the driver's steering intention control signal is executed first.

[0078] Exemplary, reference Figure 1 to Figure 4 ,as well as Figure 8 , the wire control steering system may also include: a steering motor 20, the steering motor 20 is used to output a steering torque to the steering gear 22 to change the output end position of the steering gear 22, thereby changing the steering angles of the left steering wheel 31 and the right steering wheel 32 of the vehicle, thereby changing the steering angle of the vehicle to drive the vehicle to steer. Exemplarily, the steering torque may only include the steering base torque when the vehicle is not in a deviation state. Exemplarily, the steering torque may also be the sum of the steering base torque and the deviation compensation torque when the vehicle is in a deviation state. Wherein, the above-mentioned steering base torque may be determined based on the steering wheel 10 information. Exemplarily, the above-mentioned steering base torque may be determined based on the steering wheel 10 angle in the steering wheel 10 information. For example, the steering base torque may be determined based on the current steering wheel 10 angle of the steering wheel 10 and the preset steering wheel 10 angle-steering base torque relationship. Wherein, the preset steering wheel 10 angle-steering base torque relationship may be obtained by pre-testing according to different vehicle models. Exemplarily, the steering motor 20 may include a motor. Of course, the steering motor 20 can also output a steering torque to the steering gear 22 via the reducer 21 to increase the maximum value of the steering torque output to the steering gear 22 .

[0079] Exemplarily, the steering gear 22 may be a rack steering gear 22, that is, the position information of the rack of the steering gear 22 is the position information of the output end of the steering gear 22. Of course, the steering gear 22 may also be other types of steering gears 22, and the corresponding position information of the output end of the steering gear 22 is the position information that determines the steering angle of the steering wheel.

[0080] Exemplary, reference Figure 1 to Figure 3 ,as well as Figure 5 and Figure 8The control method may further include: if the vehicle is in a deviation state, then according to the driving state information, controlling the road feel simulation motor 12 of the vehicle to output a road feel compensation torque to the steering wheel 10 of the vehicle, so as to reduce the distance between the steering wheel 10 torque in the steering wheel 10 information and the preset steering wheel 10 torque range. That is, when the vehicle is in a deviation state, not only deviation torque compensation is performed, but also road feel torque compensation is performed, so that the road feel torque output by the road feel simulation motor 12 to the steering wheel 10 is as close as possible to the preset steering wheel 10 torque range, thereby improving the driver's feel.

[0081] refer to Figures 1 to 9 The deviation compensation mode mainly completes two parts of work: one part realizes the vehicle deviation compensation correction function, through the deviation compensation torque calculation, deviation torque compensation is performed, and the vehicle deviation correction is completed by controlling the vehicle's steering motor 20 and steering gear 22. The other part is to realize the road sense compensation torque compensation function, by calculating the road sense compensation torque, inputting it to the road sense simulation motor 12 for road sense simulation torque correction, and outputting a light and comfortable simulated road sense torque to the steering wheel 10. Finally, the vehicle deviation correction and road sense simulation torque compensation are completed without affecting the driving operation experience, thereby improving the driving safety and driving comfort of the vehicle with the wire control steering system.

[0082] When controlling the road feel simulation motor 12 of the vehicle to output the road feel compensation torque to the steering wheel 10 of the vehicle according to the driving state information, various methods may be used.

[0083] Exemplary, reference Figure 1 to Figure 3 ,as well as Figure 5 and Figure 8 When the road feel simulation motor 12 of the vehicle is controlled to output the road feel compensation torque to the steering wheel 10 of the vehicle according to the driving state information, the deviation compensation torque can be determined first according to the difference between the lateral acceleration in the driving state information and the preset lateral acceleration; then, the road feel simulation motor 12 is controlled to output the road feel compensation torque to the steering wheel 10. At this time, the magnitude and direction of the road feel compensation torque can be determined according to the relative magnitude of the difference between the lateral acceleration of the vehicle and the preset lateral acceleration, so that when the road feel simulation motor 12 is controlled to output the road feel compensation torque to the steering wheel 10, the distance between the steering wheel 10 torque in the steering wheel 10 information and the preset steering wheel 10 torque range can be reduced, so that the road feel torque output by the road feel simulation motor 12 to the steering wheel 10 is as close as possible to the preset steering wheel 10 torque range, thereby improving the driver's feel.

[0084] When determining the road feel compensation torque according to the difference between the lateral acceleration in the driving state information and the preset lateral acceleration, various methods may be used.

[0085] Exemplarily, determining the road sense compensation torque according to the difference between the lateral acceleration in the driving state information and the preset lateral acceleration may include: taking the product of the second preset correction coefficient and the difference between the lateral acceleration and the preset lateral acceleration as the magnitude of the road sense compensation torque, so that the road sense compensation torque and the difference between the lateral acceleration and the preset lateral acceleration are linearly positively correlated. When determining the direction of the road sense compensation torque, it is specifically related to the relationship between the steering wheel 10 torque and the preset steering wheel 10 torque range.

[0086] Specifically, when the steering wheel 10 torque in the steering wheel 10 information is greater than the upper limit value of the preset steering wheel 10 torque range, the direction of the road feel compensation torque is determined to be opposite to the direction of the steering wheel 10 torque, that is, the direction of the road feel compensation torque at this time is opposite to the direction of the steering wheel 10 torque, so that when controlling the road feel simulation motor 12 to output the road feel compensation torque to the steering wheel 10, the difference between the steering wheel 10 torque in the steering wheel 10 information and the upper limit value of the preset steering wheel 10 torque range can be reduced, so that the road feel torque output by the road feel simulation motor 12 to the steering wheel 10 is as close as possible to the preset steering wheel 10 torque range, thereby improving the driver's feel.

[0087] When the steering wheel 10 torque is less than the lower limit value of the preset steering wheel 10 torque range, the direction of the road feel compensation torque is determined to be the same as the direction of the steering wheel 10 torque, that is, the direction of the road feel compensation torque at this time is the same as the direction of the steering wheel 10 torque, so that when controlling the road feel simulation motor 12 to output the road feel compensation torque to the steering wheel 10, the difference between the steering wheel 10 torque in the steering wheel 10 information and the lower limit value of the preset steering wheel 10 torque range can be reduced, so that the road feel torque output by the road feel simulation motor 12 to the steering wheel 10 is as close as possible to the preset steering wheel 10 torque range, thereby improving the driver's feel.

[0088] Exemplarily, the road feel compensation torque may be defined as T3, where T3 = Δa*μ.

[0089] Wherein, △a represents the difference between the current lateral acceleration a of the vehicle and the preset lateral acceleration a1. μ is the second preset correction coefficient, which is obtained based on the calibration of the specific vehicle model.

[0090] When the steering wheel 10 torque T acquired in real time is greater than Tmax, the road sense compensation torque T3 is superimposed in the opposite direction to the real-time steering wheel 10 torque T. When the steering wheel 10 torque T acquired in real time is less than Tmin, the road sense compensation torque T3 is superimposed in the same direction as the real-time steering wheel 10 torque T.

[0091] The road feel compensation torque T3 decreases linearly as the difference between the current lateral acceleration a of the vehicle and the preset lateral acceleration a1 decreases, until the torque T of the steering wheel 10 satisfies Tmin < T < Tmax, at which point the compensation torque exits and the road feel torque compensation correction is completed. The road feel torque compensation for deviation ensures that the driver always obtains the best simulated road feel torque at the steering wheel 10 end, improving the driving operation comfort.

[0092] It should be noted that during the road feel torque compensation process of the vehicle, the optimal way to end the road feel torque is as follows: control the road feel simulation motor 12 of the vehicle to output the road feel compensation torque to the steering wheel 10 of the vehicle, and reduce it until the torque of the steering wheel 10 in the steering wheel 10 information is within the preset steering wheel 10 torque range, and then exit the road feel torque compensation process. Of course, during the road feel torque compensation process of the vehicle, the above-mentioned verification of whether the vehicle is in a deviation state is also carried out. If it is determined that the vehicle is not in a deviation state due to the judgment that the driver has a steering intention, the road feel torque compensation is directly exited, and the steering intention control signal of the driver is preferentially executed.

[0093] Exemplarily, refer to Figure 1 to Figure 3 、and Figure 5 and Figure 8 ,the control method may further include: if the vehicle is in a deviation state, while controlling the road feel simulation motor 12 to output the road feel compensation torque to the steering wheel 10, the road feel simulation motor 12 is also controlled to output the road feel basic torque to the steering wheel 10.

[0094] Refer to Figure 1 to Figure 3 、and Figure 5 and Figure 8 ,if the vehicle is not in a deviation state, the road feel simulation motor 12 is controlled to output the road feel basic torque to the steering wheel 10.

[0095] Exemplarily, refer to Figure 1 to Figure 3 、and Figure 5 and Figure 8, the steer-by-wire system may further include a road sense simulation motor 12, which is used to provide a road sense torque to the steering wheel 10. Exemplarily, the above-mentioned steering wheel 10 torque is the road sense torque provided by the road sense simulation motor 12 to the steering wheel 10, that is, the road sense torque output to the steering wheel 10 by the road sense simulation motor 12 is used as the steering wheel 10 torque. Exemplarily, the above-mentioned road sense torque may only include the road sense basic torque when the vehicle is not in a running state. Exemplarily, the above-mentioned road sense torque may also be the sum of the road sense basic torque and the road sense compensation torque when the vehicle is in a running state. Among them, the above-mentioned road sense basic torque can be determined based on a preset steering wheel 10 angle-road sense basic torque relationship, and / or a preset steering wheel 10 angular velocity-road sense basic torque relationship. The preset steering wheel 10 angle-road sense basic torque relationship, and the preset steering wheel 10 angular velocity-road sense basic torque relationship can be obtained by pre-testing according to different vehicle models. Exemplarily, the steering wheel 10 is rotatably disposed on a steering column 11 , and the road feel simulation motor 12 is connected to the steering column 11 and can apply a road feel torque through the steering column 11 .

[0096] Exemplary, reference Figure 6 and Figure 7 The control method may further include: obtaining the position information of the output end of the steering gear 22 before the vehicle travels; and aligning the steering wheel 10 according to the position information of the output end of the steering gear 22 and the preset corresponding relationship. That is, before the vehicle travels, the steering wheel 10 is also aligned according to the position information of the output end of the steering gear 22 and the preset corresponding relationship, so that the steering wheel 10 is turned to the target angle.

[0097] When the steering wheel 10 is aligned according to the output terminal position information of the steering gear 22 and the preset corresponding relationship, a variety of methods can be used. Figure 6 and Figure 7 According to the position information of the output end of the steering gear 22 and the preset corresponding relationship, the steering wheel 10 is aligned, which may include: determining the target angle of the steering wheel 10 according to the position information of the output end of the steering gear 22 and the preset corresponding relationship; when the angle of the steering wheel 10 is different from the target angle, controlling the road feel simulation motor 12 of the vehicle to drive the steering wheel 10 to rotate so that the angle of the steering wheel 10 is equal to the target angle. The above-mentioned preset corresponding relationship is the preset corresponding relationship between the steering wheel 10 angle and the output end position of the steering gear 22, and the preset corresponding relationship is the corresponding relationship obtained through testing during the historical use of the vehicle or before the vehicle leaves the factory.

[0098] Exemplary, reference Figure 7The figure shows a schematic diagram of an alignment verification program for a steer-by-wire system. After detecting the vehicle power-on information, by collecting the current steering wheel 10 information (steering wheel 10 angle) and the output end position information of the steering gear 22 (for example, the rack position information of the rack-and-pinion steering gear 22), the historical steering wheel 10 angle and rack position relationship logic information (preset correspondence) is called to perform alignment verification on the steering wheel 10 angle and the output end position of the steering gear 22. If the relative relationship between the current steering wheel 10 angle of the vehicle and the output end position of the steering gear 22 is inconsistent with the preset correspondence logic, based on the current output end position, by correcting the current angle of the steering wheel 10, the alignment of the vehicle steering system is completed, providing an accurate state input for the subsequent deviation compensation control of the vehicle. Subsequently, during the vehicle driving process, the above method can be used to perform operations such as deviation state judgment, deviation compensation torque calculation, and road feel compensation torque calculation.

[0099] The following are several exemplary embodiments.

[0100] Embodiment 1: After the vehicle is powered on and there is no problem with the alignment between the steering wheel 10 angle and the output end position of the steering gear 22, during the vehicle driving process, the vehicle is continuously checked for whether it is in a deviation state.

[0101] When the vehicle driving state information satisfies: vehicle speed > preset vehicle speed V1, the wheel speed difference between the left steering wheel 31 and the right steering wheel 32 is less than the preset difference θ1, the yaw angular velocity is less than the preset yaw angular velocity ω1, and the lateral acceleration is less than the preset lateral acceleration a1, it is determined that the vehicle is in a straight-ahead state;

[0102] When the steering wheel 10 information of the vehicle satisfies: the steering wheel 10 angular velocity is less than the preset steering wheel 10 angular velocity β, the steering wheel 10 torque T ranges from Tmin < T < Tmax, and the steering wheel 10 angle is less than the preset angle α1, it is determined that the driver has no steering intention;

[0103] That is, when the vehicle is in a straight-ahead state and the driver has no steering intention, it is determined that the vehicle is not in a deviation state, that is, in a non-deviation state. The vehicle is in a normal straight-ahead working condition, and the vehicle does not perform deviation compensation correction, and continuously checks the vehicle for whether it is in a deviation state.

[0104] Embodiment 2: After the vehicle is powered on and there is no problem with the alignment between the steering wheel 10 angle and the output end position of the steering gear 22, during the vehicle driving process, the vehicle is continuously checked for whether it is in a deviation state.

[0105] When the vehicle driving state information satisfies: vehicle speed > preset vehicle speed V1, the wheel speed difference between the left steering wheel 31 and the right steering wheel 32 is not less than the preset difference θ1, the yaw angular velocity is not less than the preset yaw angular velocity ω1, and / or the lateral acceleration is not less than the preset lateral acceleration a1, it is determined that the vehicle is in a non-straight-ahead state;

[0106] When the information of the vehicle's steering wheel 10 satisfies that while the steering angle of the steering wheel 10 is not less than the preset steering angle α1, the angular velocity of the steering wheel 10 is not less than the preset angular velocity β of the steering wheel 10, and / or the range of the steering wheel torque T does not satisfy Tmin < T < Tmax, it is determined that the driver has a steering intention;

[0107] That is, when the vehicle is in a non - straight - line state and the driver has a steering intention, it is determined that the vehicle is not in a deviation state, that is, in a non - deviation state. The whole vehicle is in a normal turning driving condition, the vehicle does not perform deviation compensation correction, and continuously performs the verification link of whether the vehicle is in a deviation state.

[0108] Embodiment 3: After the vehicle is powered on and there is no problem with the alignment of the steering angle of the steering wheel 10 and the position of the output end of the steering gear 22, during the driving process of the whole vehicle, continuously verify whether the vehicle is in a deviation state.

[0109] When the driving state information of the vehicle satisfies that the vehicle speed > the preset vehicle speed V1, the wheel speed difference between the left steering wheel 31 and the right steering wheel 32 is not less than the preset difference θ1, the yaw angular velocity is not less than the preset yaw angular velocity ω1, and / or the lateral acceleration is not less than the preset lateral acceleration a1, it is determined that the vehicle is in a non - straight - line state;

[0110] When the information of the vehicle's steering wheel 10 satisfies that the angular velocity of the steering wheel 10 is less than the preset angular velocity β of the steering wheel 10, the range of the steering wheel torque T is Tmin < T < Tmax, and the steering angle of the steering wheel 10 is less than the preset steering angle α1, it is determined that the driver has no steering intention;

[0111] That is, when the vehicle is in a non - straight - line state and the driver has no steering intention, it is determined that the vehicle is in a deviation state. The whole vehicle is in a normal turning driving condition, and the vehicle subsequently enters the deviation compensation mode to perform deviation compensation correction and road - feeling torque compensation.

[0112] Reference Figure 7 、 Figure 8 and Fig. 9 The deviation compensation mode mainly completes two parts of work: one part realizes the vehicle deviation compensation correction function. Through the calculation of the deviation compensation torque, the deviation torque compensation is carried out, so as to complete the vehicle deviation correction by controlling the steering motor 20 and the steering gear 22 of the vehicle. The other part is to realize the road - feeling compensation torque compensation function. By calculating the road - feeling compensation torque and inputting it to the road - feeling simulation motor 12 for road - feeling simulation torque correction, a light and comfortable simulated road - feeling torque is output to the steering wheel 10. Finally, without affecting the driving operation feeling, the vehicle deviation correction and road - feeling simulation torque compensation are completed, improving the driving safety and driving comfort of the steer - by - wire steering system vehicle.

[0113] Exemplarily, the deviation compensation torque (which can be defined as T2) is proportional to the difference △ω between the yaw rate and the preset yaw rate. The calculation formula is: T2 = λ * △ω. Wherein, the difference △ω between the yaw rate and the preset yaw rate is the difference between the current yaw rate ω of the vehicle and the preset yaw rate ω1; λ is the first preset correction coefficient, which needs to be calibrated according to the specific vehicle model. The deviation compensation torque T2 input by the steering motor 20 to the steering gear 22 corrects the vehicle deviation to reduce the difference △ω between the yaw rate and the preset yaw rate. The deviation compensation torque T2 decreases linearly with the decrease of the difference △ω between the yaw rate and the preset yaw rate until the yaw rate ω is equal to the preset yaw rate ω1, at which point the deviation compensation torque exits, completing the vehicle deviation correction, helping the deviated vehicle to resume straight driving, and improving the driving operation safety.

[0114] It should be explained that during the vehicle deviation compensation process, the optimal way to end the deviation compensation is: control the steering motor 20 of the vehicle to output the deviation compensation torque to the steering gear 22 until the deviation amount of the vehicle decreases to zero before exiting the deviation compensation process. Of course, during the vehicle deviation compensation process, the above-mentioned verification of whether the vehicle is in a deviated state is also carried out. If it is determined that the vehicle is not in a deviated state due to the judgment that the driver has a steering intention, the deviation compensation process is directly exited, and the steering intention control signal of the driver is preferentially executed.

[0115] Exemplarily, the road feel compensation torque can be defined as T3, then T3 = △a * μ.

[0116] Wherein, △a represents the difference between the current lateral acceleration a of the vehicle and the preset lateral acceleration a1. μ is the second preset correction coefficient, and this parameter is obtained based on the calibration of the specific vehicle model.

[0117] When the torque T of the steering wheel 10 obtained in real time is greater than Tmax, the superposition direction of the road feel compensation torque T3 is opposite to the real-time torque T of the steering wheel 10. When the torque T of the steering wheel 10 obtained in real time is less than Tmin, the superposition direction of the road feel compensation torque T3 is the same as the real-time torque T of the steering wheel 10.

[0118] The road feel compensation torque T3 decreases linearly with the decrease of the difference between the current lateral acceleration a of the vehicle and the preset lateral acceleration a1 until the torque T of the steering wheel 10 satisfies Tmin < T < Tmax, at which point the compensation torque exits, completing the road feel torque compensation correction. The deviation road feel torque compensation ensures that the driver always obtains the best simulated road feel torque at the steering wheel 10 end, improving the driving operation comfort.

[0119] It should be explained that during the process of road-feel torque compensation, the optimal way to end the road-feel torque is to control the road-feel simulation motor 12 of the vehicle to output the road-feel compensation torque to the steering wheel 10 of the vehicle, and reduce it until the steering wheel 10 torque in the steering wheel 10 information is within the preset steering wheel 10 torque range, and then exit the road-feel torque compensation process. Of course, during the process of road-feel torque compensation, the above-mentioned vehicle deviation check is also performed. If the vehicle is not in the deviation state due to the judgment that the driver has a steering intention, the road-feel torque compensation is directly exited, and the driver's steering intention control signal is executed first.

[0120] In the various embodiments shown above, whether the vehicle is in a deviation state is determined based on the vehicle's driving state information and the steering wheel 10 information; if the vehicle is in a deviation state, the vehicle's steering motor 20 is controlled to output a deviation compensation torque to the steering gear 22 based on the driving state information, so as to reduce the deviation amount of the vehicle, which is beneficial for the vehicle to exit the deviation state, thereby improving the safety of the wire-controlled steering system.

[0121] In some of the above-mentioned embodiments, deviation torque compensation and road feel simulation torque correction are performed on the steer-by-wire system, thereby improving the driving safety and operating comfort of the steer-by-wire system vehicle.

[0122] In some of the above-mentioned embodiments, a method for verifying the alignment state of the steering wheel 10 of the wire-controlled steer system is also provided, by collecting the steering wheel 10 angle information, the steering gear 22 output terminal position information, and obtaining the preset correspondence information between the steering wheel 10 angle and the steering gear 22 output terminal position, to judge the alignment state of the steering wheel 10, and when the steering wheel 10 is not aligned, correct the steering wheel 10 so that the steering wheel 10 angle is located at the target angle position, thereby ensuring the accuracy of the vehicle's initial state judgment, thereby improving the effectiveness of the vehicle's deviation compensation control.

[0123] In some of the above-mentioned embodiments, mutual verification is performed based on the information of the steering wheel 10 at the upper end and the steering gear 22 at the lower end, the driving steering intention is judged by collecting the information of the steering wheel 10, and whether the vehicle is in a straight-moving state is judged according to the driving state information. The deviation compensation control algorithm is used to calculate the deviation compensation torque, and the steering motor 20 is controlled to output the deviation compensation torque to the steering gear 22 for deviation compensation, so as to help the deviated vehicle resume straight-moving and improve the safety of driving operations.

[0124] In some of the above-mentioned embodiments, mutual verification is performed based on the steering wheel 10 information at the upper end and the steering gear 22 information at the lower end. By collecting the steering wheel 10 angle, steering wheel 10 angular velocity and steering wheel 10 torque information in the steering wheel 10 information, the vehicle's driving state information is also collected, and a road feel compensation torque algorithm is used to obtain the optimal road feel compensation torque output by the road feel simulation motor 12 to the steering wheel 10, thereby ensuring that the driver's steering operation force is not increased additionally when the vehicle deviates, completing road feel torque compensation and improving driving operation comfort.

[0125] In addition, an embodiment of the present application also provides a control device for a wire-controlled steering system, which includes: a storage medium and a processor, wherein the storage medium stores a computer program run by the processor, and when the computer program is run by the processor, the processor executes any one of the above-mentioned control methods for the wire-controlled steering system.

[0126] Fig.10 FIG. 1 is a schematic block diagram of a control device 100 for a steer-by-wire system according to an embodiment of the present application. Fig.10 As shown, the control device 100 of the wire steering system according to the embodiment of the present application may include a storage medium 110 and a processor 120. The storage medium 110 stores a computer program executed by the processor 120. When the computer program is executed by the processor 120, the processor 120 executes the control method of the wire steering system according to the embodiment of the present application described above. Those skilled in the art can understand the specific operation of the deployment device of the control device 100 of the wire steering system according to the embodiment of the present application in combination with the above content, and for the sake of brevity, it will not be repeated here.

[0127] The storage medium 110 may include, for example, a memory card of a smart phone, a storage component of a tablet computer, a hard disk of a personal computer, a read-only memory (ROM), an erasable programmable read-only memory (EPROM), a portable compact disk read-only memory (CD-ROM), a USB memory, or any combination of the above storage media. The computer-readable storage medium may be any combination of one or more computer-readable storage media.

[0128] Exemplary, reference Figures 1 to 10 The control device 100 of the steer-by-wire system may be a controller in the steer-by-wire system, and illustratively, the controller may be an electronic control unit (ECU). Of course, the control device 100 of the steer-by-wire system may also be a microcontroller unit in the electronic control unit (ECU).

[0129] Exemplarily, the electronic controller (ECU) of the steer-by-wire system receives the steering wheel 10 information (such as the steering wheel 10 angle, the steering wheel 10 torque, and the steering wheel 10 angular velocity) on the one hand, and receives the vehicle's driving state information (such as vehicle speed, yaw rate, lateral acceleration, the output end position of the steering gear 22, the wheel speed of the left steering wheel 31, and the wheel speed of the right steering wheel 32) on the other hand. And also makes judgments and calculations. For example, the target front wheel angle can be calculated by the front wheel angle control algorithm, and the rotation direction, angle, and output torque of the steering motor 20 and the road sense simulation motor 12 can be controlled, and the steering wheel is controlled to steer through the steering gear 22. At the same time, the electronic controller (ECU) calculates the magnitude of the self-aligning torque according to the designed self-aligning torque algorithm, and realizes the desired driver road sense information through the road sense simulation motor 12.

[0130] Furthermore, the present application embodiment also provides a wire control steering system, referring to Figures 1 to 10 The steer-by-wire system comprises: a control device 100 of any one of the steer-by-wire systems described above.

[0131] Exemplary, reference Figures 1 to 10 , the steer-by-wire system may further include a road sense simulation motor 12, which is used to provide a road sense torque to the steering wheel 10. Exemplarily, the above-mentioned steering wheel 10 torque is the road sense torque provided by the road sense simulation motor 12 to the steering wheel 10, that is, the road sense torque output to the steering wheel 10 by the road sense simulation motor 12 is used as the steering wheel 10 torque. Exemplarily, the above-mentioned road sense torque may only include the road sense basic torque when the vehicle is not in a running state. Exemplarily, the above-mentioned road sense torque may also be the sum of the road sense basic torque and the road sense compensation torque when the vehicle is in a running state. Among them, the above-mentioned road sense basic torque can be determined based on a preset steering wheel 10 angle-road sense basic torque relationship, and / or a preset steering wheel 10 angular velocity-road sense basic torque relationship. The preset steering wheel 10 angle-road sense basic torque relationship, and the preset steering wheel 10 angular velocity-road sense basic torque relationship can be obtained by pre-testing according to different vehicle models. Exemplarily, the steering wheel 10 is rotatably disposed on a steering column 11 , and the road feel simulation motor 12 is connected to the steering column 11 and can apply a road feel torque through the steering column 11 .

[0132] Exemplary, reference Figures 1 to 10, the wire control steering system may also include: a steering motor 20, the steering motor 20 is used to output a steering torque to the steering gear 22 to change the output end position of the steering gear 22, thereby changing the steering angles of the left steering wheel 31 and the right steering wheel 32 of the vehicle, thereby changing the steering angle of the vehicle to drive the vehicle to steer. Exemplarily, the steering torque may only include the steering base torque when the vehicle is not in a deviation state. Exemplarily, the steering torque may also be the sum of the steering base torque and the deviation compensation torque when the vehicle is in a deviation state. Wherein, the above-mentioned steering base torque may be determined based on the steering wheel 10 information. Exemplarily, the above-mentioned steering base torque may be determined based on the steering wheel 10 angle in the steering wheel 10 information. For example, the steering base torque may be determined based on the current steering wheel 10 angle of the steering wheel 10 and the preset steering wheel 10 angle-steering base torque relationship. Wherein, the preset steering wheel 10 angle-steering base torque relationship may be obtained by pre-testing according to different vehicle models. Exemplarily, the steering motor 20 may include a motor. Of course, the steering motor 20 can also output a steering torque to the steering gear 22 via the reducer 21 to increase the maximum value of the steering torque output to the steering gear 22 .

[0133] Exemplary, reference Figures 1 to 10 The steering gear 22 may be a rack steering gear 22, that is, the position information of the rack of the steering gear 22 is the position information of the output end of the steering gear 22. Of course, the steering gear 22 may also be other types of steering gears 22, and the corresponding position information of the output end of the steering gear 22 is the position information for determining the steering angle of the steering wheel.

[0134] Exemplary, reference Figures 1 to 10 , a torque angle sensor can be provided to detect steering wheel 10 information such as steering wheel 10 angle, steering wheel 10 angular velocity and steering wheel 10 torque. The torque angle sensor converts the steering wheel 10 information input by the driver into an electrical signal and transmits it to the control device 100 of the wire steering system. The control device 100 of the wire steering system outputs a control signal according to the corresponding control algorithm to drive the steering gear 22 to realize the driver's steering intention. Exemplarily, the road sense simulation motor 12 receives the control signal of the control device 100 of the wire steering system and provides the road sense torque to the steering wheel 10. Exemplarily, the steering motor 20 receives the control signal of the control device 100 of the wire steering system and drives the steering gear 22 under the deceleration and torque-increasing action of the reducer 21 to realize the vehicle steering.

[0135] Furthermore, the present application embodiment also provides a vehicle, referring to Figures 1 to 10The vehicle includes: a control device of any one of the above-mentioned steer-by-wire systems, or any one of the above-mentioned steer-by-wire systems. For example, the vehicle may be a vehicle such as, but not limited to, a fuel vehicle, an electric vehicle, a hybrid vehicle, etc. For example, the vehicle may be a front-steering vehicle or a rear-steering vehicle.

[0136] The present invention has been described by the above embodiments, but it should be understood that the above embodiments are only for the purpose of example and description, and are not intended to limit the present invention to the scope of the described embodiments. In addition, it can be understood by those skilled in the art that the present invention is not limited to the above embodiments, and more variations and modifications can be made according to the teachings of the present invention, and these variations and modifications all fall within the scope of the protection claimed by the present invention. The protection scope of the present invention is defined by the attached claims and their equivalents.

Claims

1. A control method for a steer-by-wire system, characterized in that: include: Get the vehicle's current driving status information and steering wheel information; When it is determined that the vehicle is in a deviation state based on the driving state information and the steering wheel information, the steering motor of the vehicle is controlled to output a deviation compensation torque to the steering gear based on the driving state information to reduce the deviation amount of the vehicle.

2. The control method according to claim 1, characterized in that: The step of determining, based on the driving state information and the steering wheel information, that the vehicle is in a deviation state comprises: According to the driving state information, determining whether the vehicle is in a straight-moving state or a non-straight-moving state; determining, based on the steering wheel information, whether the driver of the vehicle has a steering intention; When the vehicle is in the non-straight-moving state and the driver has no steering intention, it is determined that the vehicle is in the deviation state.

3. The control method according to claim 2, characterized in that: Also includes: When the vehicle is in the straight-moving state and the driver has no intention to turn, or when the vehicle is in the non-straight-moving state and the driver has an intention to turn, it is determined that the vehicle is not in the deviation state.

4. The control method according to claim 2, characterized in that: The obtaining of the current driving state information and steering wheel information of the vehicle includes: Acquiring the vehicle speed, yaw rate, lateral acceleration, left steering wheel speed and right steering wheel speed of the vehicle, and using the vehicle speed, yaw rate, lateral acceleration, left steering wheel speed and right steering wheel speed as the driving state information; The steering wheel angle, steering wheel angular velocity, and steering wheel torque output by the road feel simulation motor of the vehicle to the steering wheel of the vehicle are obtained, and the steering wheel angle, steering wheel angular velocity, and steering wheel torque are used as the steering wheel information.

5. The control method according to claim 4, characterized in that: The determining, based on the driving state information, whether the vehicle is in a straight-moving state or a non-straight-moving state includes: When the vehicle speed is greater than a preset vehicle speed, if the difference between the left steering wheel speed and the right steering wheel speed is less than a preset difference, the yaw rate is less than a preset yaw rate, and the lateral acceleration is less than a preset lateral acceleration, it is determined that the vehicle is in the straight-ahead state; When the vehicle speed is greater than the preset vehicle speed, if the difference between the left steering wheel speed and the right steering wheel speed is not less than the preset difference, the yaw angular velocity is not less than the preset yaw angular velocity, or / and the lateral acceleration is not less than the preset lateral acceleration, it is determined that the vehicle is in the non-straight driving state.

6. The control method according to claim 4, characterized in that: The determining, based on the steering wheel information, whether the driver of the vehicle has a steering intention includes: When the steering wheel angle is less than a preset angle, the steering wheel angular velocity is less than a preset steering wheel angular velocity, and the steering wheel torque is within a preset steering wheel torque range, determining that the driver has no steering intention; When the steering wheel angle is not less than a preset angle, the steering wheel angular velocity is not less than the preset angular velocity, or / and the steering wheel torque is not within the preset steering wheel torque range, it is determined that the driver has a steering intention.

7. The control method according to any one of claims 1 to 6, characterized in that: The controlling, according to the driving state information, the steering motor of the vehicle to output a deviation compensation torque to the steering gear to reduce the deviation amount of the vehicle comprises: Determining the deviation compensation torque according to the difference between the yaw angular velocity in the driving state information and a preset yaw angular velocity; The steering motor is controlled to output the deviation compensation torque to the steering gear to reduce the difference between the yaw angular velocity and the preset yaw angular velocity.

8. The control method according to claim 7, characterized in that: The determining the deviation compensation torque according to the difference between the yaw angular velocity in the driving state information and a preset yaw angular velocity comprises: The product of the first preset correction coefficient and the difference between the yaw angular velocity and the preset yaw angular velocity is used as the magnitude of the deviation compensation torque; When the absolute value of the yaw angular velocity is greater than the absolute value of the preset yaw angular velocity, the direction of the deviation compensation torque is opposite to the direction of the yaw angular velocity; When the absolute value of the yaw angular velocity is less than the absolute value of the preset yaw angular velocity, the direction of the deviation compensation torque is the same as the direction of the yaw angular velocity.

9. The control method according to any one of claims 1 to 8, characterized in that: Also includes: If the vehicle is in the deviation state, while controlling the steering motor to output the deviation compensation torque to the steering gear, the steering motor is also controlled to output the steering basic torque to the steering gear; If the vehicle is not in the deviation state, the steering motor is controlled to output the steering basic torque to the steering gear.

10. The control method according to any one of claims 1 to 9, characterized in that: Also includes: If the vehicle is in the deviation state, the road feel simulation motor of the vehicle is controlled to output a road feel compensation torque to the steering wheel of the vehicle according to the driving state information, so as to reduce the distance between the steering wheel torque in the steering wheel information and the preset steering wheel torque range.

11. The control method according to claim 10, characterized in that: The step of controlling the road feel simulation motor of the vehicle to output a road feel compensation torque to the steering wheel of the vehicle according to the driving state information comprises: determining the road feel compensation torque according to a difference between the lateral acceleration in the driving state information and a preset lateral acceleration; The road feel simulation motor is controlled to output the road feel compensation torque to the steering wheel.

12. The control method according to claim 11, characterized in that: The determining the road feel compensation torque according to the difference between the lateral acceleration in the driving state information and the preset lateral acceleration includes: taking the product of the second preset correction coefficient and the difference between the lateral acceleration and the preset lateral acceleration as the magnitude of the road feel compensation torque; When the steering wheel torque in the steering wheel information is greater than an upper limit value of a preset steering wheel torque range, determining that the direction of the road feel compensation torque is opposite to the direction of the steering wheel torque; When the steering wheel torque is less than a lower limit value of a preset steering wheel torque range, the direction of the road feel compensation torque is determined to be the same as the direction of the steering wheel torque.

13. The control method according to claim 10, characterized in that: Also includes: If the vehicle is in the deviation state, while controlling the road feel simulation motor to output the road feel compensation torque to the steering wheel, the road feel simulation motor is also controlled to output the road feel basic torque to the steering wheel; If the vehicle is not in the deviation state, the road feel simulation motor is controlled to output the road feel basic torque to the steering wheel.

14. The control method according to any one of claims 1 to 13, characterized in that: Also includes: Before the vehicle travels, obtaining the position information of the output end of the steering gear; Determining a target angle of the steering wheel according to the position information of the steering gear output end and a preset corresponding relationship; When the steering wheel angle is different from the target steering angle, the road feel simulation motor of the vehicle is controlled to drive the steering wheel to rotate so that the steering wheel angle is equal to the target steering angle.

15. A control device for a steer-by-wire system, characterized in that: include: A storage medium and a processor, wherein the storage medium stores a computer program to be executed by the processor, and when the computer program is executed by the processor, the processor executes the control method of the wire control steering system according to any one of claims 1 to 14.

16. A steer-by-wire system, characterized in that: include: The control device for a steer-by-wire system as claimed in claim 15.

17. A vehicle, characterized in that: include: A control device for a steer-by-wire system as claimed in claim 15, or a steer-by-wire system as claimed in claim 16.

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