Vehicle steering control method, device, vehicle and storage medium

Abstract

The present invention relates to a vehicle steering control method, device, vehicle and storage medium, including obtaining vehicle posture data when receiving a lateral control request, wherein the lateral control request includes lateral control desired data; determining a steering assist demand torque based on the vehicle posture data and the lateral control desired data; determining kingpin projection point arm data based on the steering assist demand torque; determining a target suspension height based on the kingpin projection point arm data; and adjusting the vehicle suspension to the target suspension height to perform vehicle steering. The present invention realizes differential steering assist by actively adjusting the kingpin projection point position through the suspension system when receiving a lateral control request, i.e., intending to control vehicle steering, thereby improving the vehicle's steering assist capability.

Description

Technical Field

[0001] The present invention relates to the technical field of vehicle chassis control, and in particular to a vehicle steering control method, a vehicle steering control device, a vehicle and a computer-readable storage medium. Background Art

[0002] For the centralized drive architecture, since the driving force output by the left and right wheels is equal and the kingpin structure of each wheel is symmetrical on the left and right, the rotational torque formed around the kingpin of each wheel is equal. The rotational torques cancel each other out after acting on the steering trapezoid. Therefore, the driving force cannot form an effective torque on the steering mechanism to control the steering mechanism, and the differential steering function cannot be realized, and the steering ability is weak. Summary of the invention

[0003] One of the objects of the present invention is to provide a vehicle steering control method to solve the problem in the prior art, such as in a centralized drive architecture, that the differential steering function cannot be realized and the steering ability is weak; the second object is to provide a vehicle steering control device; the third object is to provide a vehicle; and the fourth object is to provide a computer-readable storage medium.

[0004] In order to achieve the above object, the technical solution adopted by the present invention is as follows:

[0005] A vehicle steering control method, the method comprising:

[0006] Upon receiving a lateral control request, acquiring vehicle posture data, wherein the lateral control request includes lateral control desired data;

[0007] Determining a steering assist torque requirement according to the vehicle posture data and the lateral control expectation data;

[0008] Determining the kingpin projection point moment arm data according to the steering assist required torque;

[0009] Determining a target suspension height based on the kingpin projection point moment arm data;

[0010] The vehicle suspension is adjusted to the target suspension height to perform vehicle steering.

[0011] Furthermore, the method further comprises:

[0012] Calculating a first assist torque according to the kingpin projection point moment arm data;

[0013] In response to the first assist torque being less than the steering assist required torque, determining a vehicle steering axis and a vehicle non-steering axis;

[0014] The driving force of the steering shaft of the vehicle is increased and the driving force of the non-steering shaft of the vehicle is reduced to increase the first assist torque to a second assist torque.

[0015] Furthermore, the method further comprises:

[0016] In response to the second assist torque being less than the steering assist request torque, the braking force of the wheels of the vehicle steering shaft is increased to increase the second assist torque to a third assist torque.

[0017] Furthermore, the method further comprises:

[0018] In response to the third assist torque being less than the steering assist required torque, determining a rotation direction according to the lateral control desired data;

[0019] determining a yaw torque based on the rotation direction;

[0020] The vehicle is controlled to reach the yaw torque to increase the third assist torque to a fourth assist torque.

[0021] Furthermore, the method further comprises:

[0022] generating steering assist abnormality information in response to the fourth assist torque being less than the steering assist required torque;

[0023] The power steering abnormality information is sent.

[0024] Furthermore, the method further comprises:

[0025] Get the vehicle steering system status;

[0026] In response to the vehicle steering system being in a power-assist failure state, determining the kingpin projection point moment arm data according to the steering power-assist demand torque is performed.

[0027] Further, the step of determining the steering assist required torque according to the vehicle posture data and the lateral control expected data comprises:

[0028] Determining a lateral control deviation between the lateral control desired data and the vehicle posture data;

[0029] determining a feedback control amount according to the lateral control deviation;

[0030] determining a feedforward control amount according to the lateral control desired data;

[0031] The steering assist required torque is determined by combining the feedback control amount and the feedforward control amount.

[0032] Further, the step of determining the kingpin projection point arm data according to the steering assist torque requirement includes:

[0033] Get the current driving force;

[0034] The quotient of the steering assist torque requirement and the current driving force is determined as the kingpin projection point arm data.

[0035] Further, the step of determining the suspension height based on the kingpin projection point moment arm data includes:

[0036] Obtain the mapping relationship between the kingpin projection point force arm data and the suspension height;

[0037] Based on the mapping relationship, the suspension height corresponding to the kingpin projection point force arm data is determined as the target suspension height.

[0038] A vehicle steering control device, the device comprising:

[0039] A first acquisition module, configured to acquire vehicle posture data when receiving a lateral control request, wherein the lateral control request includes lateral control expected data;

[0040] A first determination module, configured to determine a steering assist torque requirement according to the vehicle posture data and the lateral control expectation data;

[0041] A second determination module is used to determine the kingpin projection point arm data according to the steering assist required torque;

[0042] A third determination module, configured to determine the suspension height based on the kingpin projection point moment arm data;

[0043] The adjustment module is used to adjust the vehicle suspension to the suspension height so as to perform vehicle steering.

[0044] A vehicle comprises a processor, a memory and a computer program stored in the memory and capable of running on the processor, wherein the computer program implements the steps of the vehicle steering control method as described above when executed by the processor.

[0045] A computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the steps of the vehicle steering control method described above are implemented.

[0046] Beneficial effects of the present invention:

[0047] The embodiment of the present invention adjusts the vehicle suspension to a target suspension height so that the relative distance between each wheel corresponding to the vehicle suspension and the vehicle body changes, thereby controlling the kingpin projection moment arm of each wheel to match the kingpin projection point moment arm data; steering is performed in this way, which is equivalent to controlling the kingpin projection moment arm difference of the left and right wheels of the vehicle to control the rotational torque difference of the left and right wheels around the kingpin, realizing differential power steering, and thus improving the steering ability of the vehicle. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] Figure 1 A flow chart of steps of an embodiment of a vehicle steering control method of the present invention;

[0049] Figure 2 A flowchart of another vehicle steering control method embodiment of the present invention;

[0050] Figure 3 It is a schematic diagram of the kingpin projection point requirements under the upper and lower viewing angles;

[0051] Figure 4 A schematic diagram of the change of the kingpin projection force arm when the wheel height is adjusted through the active suspension from the front and rear perspectives;

[0052] Figure 5a It is a schematic diagram of five-differential steering from top and bottom perspectives;

[0053] Figure 5b A schematic diagram of achieving differential steering by controlling the wheel kingpin projection lever arm from top and bottom perspectives;

[0054] Figure 6 A flowchart of the steps of an exemplary vehicle steering control method of the present invention;

[0055] Figure 7 A structural block diagram of an embodiment of a vehicle steering control device of the present invention;

[0056] Figure 8 A schematic diagram of a processor and a storage medium of a vehicle embodiment of the present invention;

[0057] Fig. 9 A schematic diagram of an embodiment of a computer-readable storage medium of the present invention. DETAILED DESCRIPTION

[0058] The following will describe the embodiments of the present invention with reference to the accompanying drawings and preferred embodiments. Those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention. It should be understood that the preferred embodiments are only for illustrating the present invention, not for limiting the scope of protection of the present invention.

[0059] It should be noted that the illustrations provided in the following embodiments are only schematic illustrations of the basic concept of the present invention, and thus the drawings only show components related to the present invention rather than being drawn according to the number, shape and size of components in actual implementation. In actual implementation, the type, quantity and proportion of each component may be changed arbitrarily, and the component layout may also be more complicated.

[0060] Reference Figure 1 , shows a flow chart of steps of an embodiment of a vehicle steering control method of the present invention. The vehicle steering control method may specifically include the following steps:

[0061] Step 101, upon receiving a lateral control request, obtaining vehicle posture data, wherein the lateral control request includes lateral control desired data;

[0062] When the driver intends to control the vehicle steering through the steering wheel or other drive-by-wire devices, or when the user turns on the automatic driving function and the automatic driving controller controls the vehicle steering, a lateral control request is generated. That is, the lateral control request is a control request issued by the vehicle controller or the user when the user intends to control the vehicle steering. Among them, the lateral control request includes lateral control expected data, which is the target data expected to be achieved when controlling the vehicle steering; such as the expected steering wheel angle, the expected turning radius, the planned driving path, etc.

[0063] When a lateral control request is received, the current vehicle posture data of the vehicle can be obtained from various sensors on the vehicle. The vehicle posture data is the posture data of the vehicle during steering control, such as the actual steering wheel angle, the actual turning radius, etc.

[0064] The embodiments of the present invention can be applied to a centralized power architecture as well as a distributed power architecture. And because the centralized power architecture cannot realize differential operation through the wheel-end motors, the embodiments of the present invention are applied to the centralized power architecture, so that the centralized power architecture realizes differential steering. Among them, the centralized drive architecture and the distributed drive architecture are relative. The distributed drive architecture is a drive architecture in which drive structures are respectively arranged on the left and right sides of the vehicle, such as a drive architecture in which the left and right wheels are driven by two motors. As for the rest, such as a motor or an engine driving the drive shaft of the vehicle, a drive architecture in which a single drive structure drives the left and right wheels is a centralized drive architecture.

[0065] Step 102, determining a steering assist torque requirement according to the vehicle posture data and the lateral control expectation data;

[0066] Based on the comparison between the actual vehicle posture in the vehicle posture data and the control target in the lateral control expectation data, the steering power requirement torque is determined. The steering power requirement torque is the torque required for the power assistance when the vehicle is steering.

[0067] Step 103, determining the kingpin projection point moment arm data according to the steering assist required torque;

[0068] The length of the kingpin projection point lever arm is determined according to the magnitude of the steering assist torque requirement, that is, the kingpin projection point lever arm data is determined. The kingpin projection lever arm is the relative position distance between the kingpin projection point of the wheel on the ground and the corresponding wheel contact point with the ground.

[0069] Step 104, determining a target suspension height based on the kingpin projection point moment arm data;

[0070] The position that the kingpin needs to reach can be determined based on the kingpin projection point force arm data, and then the target suspension height that the suspension needs to reach can be determined. The target suspension height is the height that the vehicle suspension needs to reach after adjustment.

[0071] Step 105 , adjusting the vehicle suspension to the target suspension height to perform vehicle steering.

[0072] The vehicle suspension can be an active suspension, such as an air suspension, an electromagnetic suspension, etc., which can actively adjust the height of the suspension. The vehicle suspension is adjusted to the target suspension height, and the vehicle is steered. Due to the change in the vehicle suspension, the relative distance between each wheel corresponding to the vehicle suspension and the vehicle body changes, and then the kingpin projection force arm of each wheel is controlled to match the kingpin projection point force arm data to achieve differential power steering.

[0073] The embodiment of the present invention obtains vehicle posture data when receiving a lateral control request, wherein the lateral control request includes lateral control desired data; determines the steering assist torque required based on the vehicle posture data and the lateral control desired data; determines the kingpin projection point arm data based on the steering assist torque required; determines the target suspension height based on the kingpin projection point arm data; and adjusts the vehicle suspension to the target suspension height to perform vehicle steering. By adjusting the vehicle suspension to the target suspension height, the relative distance between each wheel corresponding to the vehicle suspension and the vehicle body changes, thereby controlling the kingpin projection arm of each wheel to match the kingpin projection point arm data; steering is performed in this way, which is equivalent to controlling the kingpin projection arm difference between the left and right wheels of the vehicle to control the torque difference of the left and right wheels rotating around the kingpin, thereby achieving differential power steering, thereby improving the steering ability of the vehicle.

[0074] Reference Figure 2 , shows a flow chart of steps of an embodiment of a vehicle steering control method of the present invention. The vehicle steering control method may specifically include the following steps:

[0075] Step 201, upon receiving a lateral control request, obtaining vehicle posture data, wherein the lateral control request includes lateral control desired data;

[0076] First, for the vehicle to which the embodiment of the present invention is applied, a larger kingpin projection arm is obtained, that is, the distance between the kingpin projection point on the ground and the corresponding wheel contact point with the ground. When designing the suspension structure, the kingpin inclination angle and the kingpin castor angle need to be appropriately increased. Figure 3 As shown, when the wheel height is adjusted by the suspension, different types of suspensions have different capabilities in how many areas the kingpin projection point of the steering wheel can fall into. In a preferred example of an embodiment of the present invention, the suspension structure can make the projection point fall into eight areas A, B, C, D, E, F, G, and H. The distance between the two farthest kingpin projection points of the worst suspension structure is greater than 10 cm.

[0077] When receiving a lateral control request, that is, when it is determined that the vehicle is being controlled to turn, the vehicle posture data can be obtained through measurement systems such as steering wheel angle sensors, inertial navigation sensors, and positioning systems. The lateral control request includes lateral control expectation data.

[0078] Step 202, determining a steering assist torque requirement according to the vehicle posture data and the lateral control expectation data;

[0079] The gap between the vehicle posture data and the desired lateral control data can be determined, and the steering assist torque required when turning can be determined.

[0080] Furthermore, the step of determining the steering assist required torque according to the vehicle posture data and the lateral control expected data comprises:

[0081] Sub-step S2021, determining a lateral control deviation between the lateral control desired data and the vehicle posture data;

[0082] First, the lateral control desired data and the corresponding data in the vehicle posture data can be subtracted to determine the lateral control deviation between the lateral control desired data and the vehicle posture data. The lateral control deviation is the deviation between the current posture and the target during lateral control.

[0083] Sub-step S2022, determining a feedback control amount according to the lateral control deviation;

[0084] The lateral control deviation is used as the feedback amount of the closed-loop control to determine the feedback control amount corresponding to the lateral control deviation. The closed-loop control includes but is not limited to PID (proportional integral differential) control, and the feedback control amount is determined based on a specific control amount calculation method. In addition, the feedback control amount can also be output based on the trained neural network model and the lateral control deviation as input. The training process and method of the neural network model are not specifically limited.

[0085] Sub-step S2023, determining a feedforward control amount according to the lateral control expected data;

[0086] Accordingly, the lateral control expected data can also be used as the target of closed-loop control to determine the feedforward control amount corresponding to the lateral control expected data. The closed-loop control includes but is not limited to PID (proportional integral differential) control, and the feedforward control amount is determined based on a specific control amount calculation method. In addition, the feedforward control amount can also be output based on the trained neural network model and the lateral control expected data as input. The training process and method of the neural network model are not specifically limited.

[0087] Sub-step S2023, determining the steering assist required torque by combining the feedback control amount and the feedforward control amount.

[0088] Finally, the feedback control amount and the feedforward control amount are combined, that is, the value obtained by adding the feedback control amount and the feedforward control amount is the steering assist required torque.

[0089] Step 203, obtaining the vehicle steering system status;

[0090] When determining whether differential steering control intervention is required, it can be determined by obtaining the vehicle steering system status. For example, the health status of the steering system and the system's ability to provide steering assistance can be obtained. If the steering assistance capability is greater than the user's required steering assistance torque, the user's needs are met by the steering system. If the steering system fails or has insufficient capability, it can be determined that the vehicle's steering system is in a power assistance failure state, and the suspension system needs to be coordinated to supplement the required steering assistance.

[0091] Step 204, in response to the vehicle steering system being in a power-assist failure state, determining the kingpin projection point moment arm data according to the steering power-assist demand torque;

[0092] In response to the vehicle steering system being in a power-assist failure state, ie, the suspension system needs to be coordinated to supplement the required steering assist, the kingpin projection point moment arm data may be determined based on the steering assist demand torque.

[0093] like Figure 4As shown in the figure, when the height of a wheel relative to the vehicle body is adjusted separately, the kingpin projection arm of the corresponding wheel will change with the change of the wheel height. Therefore, after the suspension structure design is completed, the relationship between the relative height h between the wheel and the vehicle body and the kingpin projection arm d is determined, assuming that: d = f(h); where h is the relative height of a wheel and the vehicle body; d is the kingpin projection arm. The required kingpin projection arm d = x for a wheel can be achieved by controlling the relative height of the wheel and the vehicle body to hx, where x = f(hx) must be satisfied.

[0094] For vehicles equipped with a centralized drive system, since the power source is concentrated in the engine or drive motor, the driving force at the wheel end is distributed to the left and right wheels through the differential, so the driving force provided by the ground to the left and right wheels is equal. Figure 5a As shown, that is, F1=F2, and because the vehicle suspension is symmetrically designed, the kingpin projection arm d1=d2; therefore, for the left wheel, the driving force generates a torque F1*d1 around the kingpin; for the right wheel, the driving force generates a torque F2*d2 around the kingpin; and the left and right wheels are connected together through a steering mechanism, and the steering mechanism is subjected to a steering torque of F1*d1+F2*d2; and because F1*d1 and F2*d2 are equal in magnitude and opposite in direction, the rotational torque of the wheel driving force acting on the steering mechanism is 0, which means that the movement of the steering mechanism cannot be controlled by changing the magnitude of the driving force, that is, differential steering cannot be achieved. In the embodiment of the present invention, the kingpin projection arm d1 and d2 can be actively adjusted by the suspension, such as Figure 5b As shown, when the control kingpin projection arm d1 is not equal to d2, the steering torque F1*d1+F2*d2 received by the steering mechanism is not 0. At this time, the total torque will act on the steering mechanism, driving the steering wheel to rotate around the kingpin to realize the differential steering function.

[0095] The magnitude of the steering torque on the steering mechanism ranges from -(F1*d1+F2*d2) to +(F1*d1+F2*d2); negative (-) indicates the direction of the torque required for the front left wheel to rotate counterclockwise around the kingpin, and positive (+) indicates the direction of the torque required for the front left wheel to rotate clockwise around the kingpin. In differential steering control, the magnitude of the steering assist torque is adjusted in real time by changing the magnitude of the driving force F1, F2 (F1 is equal to F2 in a centralized drive system), or by changing the magnitude of the kingpin projection arm d1, d2, or by changing the magnitude of F1, F2, d1, d2 at the same time, to meet the user's steering assist request.

[0096] When the driver's longitudinal request (such as throttle depth) is determined, the expected longitudinal force acting on the entire vehicle is determined. When the braking system is not working, the driving force acting on the steering wheel satisfies: F1=F2, and F1+F2<=FmaxL; where FmaxL is the user's expected driving force from the ground on the vehicle longitudinally.

[0097] Furthermore, the step of determining the kingpin projection point arm data according to the steering assist torque requirement includes:

[0098] Step S2041, obtaining the current driving force;

[0099] By determining the moment arm data of the kingpin projection point, the current driving force of the vehicle can be obtained.

[0100] Step S2042, determining the quotient of the steering assist torque requirement and the current driving force as the kingpin projection point arm data.

[0101] It can be known from the torque formula that the torque divided by the action force can be used to obtain the lever arm size. To this end, the steering assistance required torque can be divided by the current driving force, that is, the quotient of the steering assistance required torque and the current driving force is the kingpin projection point lever arm data.

[0102] Step 205, determining a target suspension height based on the kingpin projection point moment arm data;

[0103] After the kingpin projection point moment arm data is obtained, the target suspension height is determined based on the relationship between the kingpin projection point moment arm data and the suspension height.

[0104] Furthermore, the step of determining the suspension height based on the kingpin projection point moment arm data comprises:

[0105] Step S2051, obtaining the mapping relationship between the kingpin projection point moment arm data and the suspension height;

[0106] Based on the mechanical structure of the suspension system, the mapping relationship between the kingpin projection point arm data and the suspension height can be determined in advance, and the mapping relationship can be stored in the vehicle controller, and the mapping relationship between the kingpin projection point arm data and the suspension height can be read from the relevant storage space.

[0107] Step S2052: Based on the mapping relationship, determine the suspension height corresponding to the kingpin projection point moment arm data as the target suspension height.

[0108] Based on the mapping relationship, a table lookup method is used to determine the suspension height corresponding to the current kingpin projection point force arm data as the target suspension height.

[0109] Step 206, adjusting the vehicle suspension to the target suspension height to perform vehicle steering;

[0110] The vehicle suspension is adjusted to a target suspension height through a corresponding suspension control method, so that the vehicle can be steered at this suspension height to achieve differential steering.

[0111] Step 207, calculating a first assist torque according to the kingpin projection point moment arm data;

[0112] In addition, due to the mechanical structure limitation of the suspension, the kingpin projection point arm data has a certain adjustment range, and the current achievable power-assist torque, i.e., the first power-assist torque, can be determined based on the kingpin projection point arm data. The first power-assist torque is the steering power-assist torque achieved by the change in the kingpin projection point arm data after adjusting only the suspension height. The first power-assist torque can be obtained by multiplying the kingpin projection point arm data with the current driving force.

[0113] Step 208, in response to the first power-assist torque being less than the steering-assistance-required torque, determining a vehicle steering axis and a vehicle non-steering axis;

[0114] Determine whether the first power-assist torque is less than the required power-steering torque. When the first power-assist torque is not less than the required power-steering torque, it means that the current power-assist torque can meet the demand, and the target suspension height can be maintained for steering. When the first power-assist torque is less than the required power-steering torque, it means that adjusting the suspension height and then adjusting the kingpin projection point force arm data for differential steering still cannot meet the demand. The vehicle steering axis and the vehicle non-steering axis can be determined. For example, the vehicle is a front-axle steering vehicle, that is, the vehicle steering axis is the front axle, and the vehicle non-steering axis is the vehicle non-steering axis.

[0115] Step 209, increasing the driving force of the steering shaft of the vehicle and reducing the driving force of the non-steering shaft of the vehicle to increase the first assist torque to a second assist torque;

[0116] The driving force of the vehicle's steering shaft can be increased, and the driving force of the vehicle's non-steering shaft can be reduced simultaneously. The value of the driving force increased by the vehicle's steering shaft is the same as the value of the driving force reduced by the vehicle's non-steering shaft, thereby keeping the total driving force unchanged. In the process of driving force transfer, the first assist torque is increased to the second assist torque. The second assist torque is the assist torque that can be achieved after adjusting the driving force.

[0117] For example, for a vehicle driven by dual power sources on the front and rear axles, the differential steering assist torque F1*d1+F2*d2 can be increased from the first assist torque to the second assist torque by transferring the rear axle drive force to the front axle, that is, increasing the front axle drive force and reducing the rear axle drive force, while ensuring that the drive forces of the two axles remain unchanged to increase F1 and F2.

[0118] Step 210 : In response to the second assist torque being less than the steering assist requirement torque, increasing the braking force of the wheels of the vehicle steering shaft to increase the second assist torque to a third assist torque.

[0119] After the power-assist torque is increased by adjusting the driving force, it can be further determined whether the second power-assist torque is less than the steering power-assist requirement torque. If the second power-assist torque is not less than the steering power-assist requirement torque, the lateral demand for steering can be met, and the current driving force distribution and suspension height can be maintained for steering.

[0120] When the second power-assist torque is less than the steering power-assist demand torque, further adjustment is required. In response to the second power-assist torque being less than the steering power-assist demand torque, the braking force of the wheels of the vehicle steering shaft can be increased, that is, the braking force of the wheels of the vehicle steering shaft is increased to increase the force and thus increase the second power-assist torque to the third power-assist torque. The third power-assist torque is the steering power-assist torque that can be provided after adjusting the braking force of the wheels of the vehicle steering shaft.

[0121] For example, equal braking force Fb is applied to the two wheels of the non-steering axle (such as the two wheels on the rear axle), and the driving force of the two driving wheels is increased at the same time. The driving force of the two driving wheels is increased synchronously by Fb, which ensures that the longitudinal force of the whole vehicle remains unchanged. At the same time, the steering assist is increased, thereby increasing the second assist torque to the third assist torque.

[0122] Step 211, in response to the third assist torque being less than the steering assist required torque, determining a rotation direction according to the lateral control expected data;

[0123] After the power-assist torque is increased by adjusting the braking force, it can be further determined whether the third power-assist torque is less than the steering power-assist demand torque. If the third power-assist torque is not less than the steering power-assist demand torque, the lateral demand for steering can be met, that is, the current braking force distribution, the current driving force distribution and the suspension height can be maintained for steering.

[0124] When the third power-assist torque is less than the steering power-assist demand torque, further adjustment is required, and the turning direction can be determined according to the steering wheel angle data in the lateral control expected data in response to the third power-assist torque being less than the steering power-assist demand torque. If the steering wheel angle data indicates that the vehicle turns left, the turning direction can be determined to be left.

[0125] Step 212, determining a yaw torque based on the rotation direction;

[0126] Use the rotation direction to determine the yaw torque the vehicle can withstand while maintaining stability.

[0127] Step 213, controlling the vehicle to reach the yaw torque to increase the third assist torque to a fourth assist torque;

[0128] The vehicle is controlled to reach the yaw torque, and the yaw moment is applied to the whole vehicle by transferring the braking force of the left and right wheels. Under the premise that the vehicle is not unstable, due to the existence of the yaw moment, a lateral force will be generated on the steering wheel to balance the yaw moment. The direction of the lateral force can be changed by changing the direction of the yaw moment. When the driver's steering expectation is determined and the kingpin projection landing point is determined before or after the tire contact point, the direction of the expected lateral force is also determined. In this way, the yaw moment of the corresponding direction can be applied through the braking system to generate lateral force, thereby providing the vehicle with yaw steering assistance and increasing the third assistance torque to the fourth assistance torque.

[0129] In addition, when any of the above conditions can satisfy the steering assistance condition to assist the vehicle in steering, the differential steering can be exited based on the reverse order of the above process.

[0130] Step 214, in response to the fourth power-assist torque being less than the steering-assist demand torque, generating steering-assist abnormality information;

[0131] After the power-assist torque is increased by increasing the yaw torque, it can be further determined whether the fourth power-assist torque is less than the steering power-assist requirement torque. The fourth power-assist torque is not less than the steering power-assist requirement torque, which means that the lateral demand for steering can be met, that is, the current vehicle state can be maintained for steering.

[0132] When the third assist torque is less than the steering assist requirement torque, it means that even if the current vehicle is adjusted to provide the maximum assist torque, it still cannot meet the lateral control requirement, and steering assist abnormality information can be generated.

[0133] Step 215, sending the power steering abnormality information.

[0134] The steering assist abnormality information is sent to the vehicle's driving controller or the vehicle's central control instrument to inform the driving controller or the user that the current steering assist is difficult to meet the requirements, and remind the driving controller or the user to take corresponding measures to perform safe steering.

[0135] The embodiment of the present invention provides a method for implementing differential power steering for vehicles with traditional centralized power structures by means of actively adjusting the position of the kingpin projection point through the suspension system, transferring the torque of the front and rear axles of the power system, and applying braking force and yaw moment through the braking system, thereby greatly improving the vehicle's power steering capability. In normal use scenarios, the traditional power steering motor can work in coordination with the differential steering system described in the embodiment of the present invention to reduce the power of the traditional power steering motor and reduce costs; in the case of abnormal steering system failure, steering capability can be provided and steering safety can be increased. For example, in the case of failure of the power steering motor, the suspension, drive and braking systems can be coordinated and controlled to ensure that the vehicle has redundant steering function in the form of differential power steering.

[0136] In order to make the implementation process of the embodiment of the present invention more clear to those skilled in the art, an example is used to illustrate as follows:

[0137] You can refer to Figure 6 , showing a step flow chart of an example of a vehicle steering control method of the present invention.

[0138] When the driver turns on the autopilot function through the steering wheel or other drive-by-wire devices, the driver and the autopilot controller form a lateral control request and send it to the differential steering control module. The differential steering control module then coordinates the control of the suspension, steering, braking, and drive systems in the following steps to meet the steering control needs of the driver and the autopilot controller.

[0139] 1) After the differential steering control module receives the lateral control request from the driver or the self-driving controller, such as the expected steering wheel angle, the expected turning radius, or the planned trajectory and other lateral control expected data, the differential steering control module measures the actual steering wheel angle, the actual turning radius, and other vehicle posture data of the vehicle based on the steering wheel angle sensor, the inertial navigation sensor, the positioning system, etc., and then subtracts the lateral control expected data from the actual lateral posture information of the vehicle, that is, the vehicle posture data, to obtain the lateral control deviation.

[0140] 2) The lateral control deviation value is input into the lateral feedback control algorithm model to obtain the feedback control quantity Tf, where Tf represents the required steering torque calculated by the feedback control algorithm module; the lateral feedback control algorithm model is trained by the control feedback quantity of the vehicle during the simulated steering control in advance.

[0141] 3) Inputting the lateral control expected value into the lateral feedforward control algorithm model to obtain the feedforward control quantity Tp, where Tp represents the required steering torque calculated by the feedforward control algorithm module; the lateral feedforward control algorithm model is trained by the control feedforward quantity of the vehicle's pre-simulated steering control.

[0142] 4) The feedforward control amount Tp plus the feedback control amount Tf gives the steering assist torque required by the user.

[0143] 5) The differential steering control module checks the health status of the steering system and the system's ability to provide steering assistance. If the ability is greater than the steering assistance torque required by the user, the user's needs are met by the steering system. If the steering system fails or has insufficient ability, the differential steering control module coordinates the suspension system to supplement the required steering assistance.

[0144] 6) The differential steering control module adjusts the wheel height through the suspension to control the kingpin projection point position, obtains the desired kingpin projection point force arm, and thus provides differential steering assistance. If the sum of the steering assistance provided by the steering system and the differential steering assistance provided by the suspension system is greater than the steering assistance torque required by the user, the user's demand is met by the steering system plus the suspension system.

[0145] 7) If the steering system plus the suspension system cannot meet the steering assist torque required by the user, the differential steering control module coordinates the power system to increase the steering assist torque by transferring the driving torque of the non-steering shaft to the steering shaft. If the sum of the steering assist provided by the steering system plus the differential steering assist provided by the suspension system plus the differential assist provided by the power system is greater than the steering assist torque required by the user, the user's demand is met by the steering system plus the suspension system plus the drive system.

[0146] 8) If the steering system plus the suspension system plus the drive system cannot meet the user's steering power torque requirements, the differential steering control module coordinates the braking system to increase the steering power torque by applying braking force to the non-steering shaft and increasing the driving force to the steering shaft. If it still cannot meet the user's needs, the left wheel braking force is transferred to the right, or the right wheel braking force is transferred to the left, and a yaw moment is applied to the entire vehicle to increase the steering power torque. If the steering system, suspension system, power system, and braking system provide power steering forces that still cannot meet the user's steering power requirements, it can be determined that the vehicle's capabilities in this scenario cannot meet the user's needs.

[0147] 9) The abnormal situation that the vehicle cannot meet the user's needs is generated as abnormal steering assistance information and fed back to the driver or the automatic driving controller.

[0148] It should be noted that, for the sake of simplicity, the method embodiments are described as a series of action combinations, but those skilled in the art should be aware that the embodiments of the present invention are not limited by the order of the actions described, because according to the embodiments of the present invention, certain steps can be performed in other orders or simultaneously. Secondly, those skilled in the art should also be aware that the embodiments described in the specification are all preferred embodiments, and the actions involved are not necessarily required by the embodiments of the present invention.

[0149] Reference Figure 7 , shows a structural block diagram of an embodiment of a vehicle steering control device of the present invention, and the vehicle steering control device may specifically include the following modules:

[0150] A first acquisition module 701 is used to acquire vehicle posture data when receiving a lateral control request, wherein the lateral control request includes lateral control expected data;

[0151] A first determination module 702, configured to determine a steering assist torque requirement according to the vehicle posture data and the lateral control expectation data;

[0152] A second determination module 703 is used to determine the kingpin projection point moment arm data according to the steering assist required torque;

[0153] A third determination module 704 is used to determine the suspension height based on the kingpin projection point moment arm data;

[0154] The adjustment module 705 is used to adjust the vehicle suspension to the suspension height to perform vehicle steering.

[0155] In an optional embodiment of the present invention, the device further comprises:

[0156] A fourth determination module, configured to calculate a first assist torque according to the kingpin projection point moment arm data;

[0157] a first response module, configured to determine a vehicle steering axis and a vehicle non-steering axis in response to the first assist torque being less than the steering assist required torque;

[0158] The driving control module is used to increase the driving force of the steering shaft of the vehicle and reduce the driving force of the non-steering shaft of the vehicle to increase the first assist torque to a second assist torque.

[0159] In an optional embodiment of the present invention, the device further comprises:

[0160] The second response module is configured to increase the braking force of the wheels of the vehicle steering shaft in response to the second assist torque being less than the steering assist required torque, so as to increase the second assist torque to a third assist torque.

[0161] In an optional embodiment of the present invention, the device further comprises:

[0162] a third response module, configured to determine a rotation direction according to the lateral control expected data in response to the third assist torque being less than the steering assist required torque;

[0163] a fifth determination module, configured to determine a yaw torque based on the rotation direction;

[0164] The torque control module is used to control the vehicle to reach the yaw torque to increase the third assist torque to a fourth assist torque.

[0165] In an optional embodiment of the present invention, the device further comprises:

[0166] a fourth response module, configured to generate steering assistance abnormality information in response to the fourth assistance torque being less than the steering assistance required torque;

[0167] The sending module is used to send the power steering abnormality information.

[0168] In an optional embodiment of the present invention, the device further comprises:

[0169] An acquisition module, used for acquiring the state of the vehicle steering system;

[0170] A fifth response module is used for executing the step of determining the kingpin projection point moment arm data according to the steering assist required torque in response to the vehicle steering system being in an assist failure state.

[0171] In an optional embodiment of the present invention, the first determining module 702 includes:

[0172] a deviation determination submodule, used to determine a lateral control deviation between the lateral control desired data and the vehicle posture data;

[0173] A feedback control amount determination submodule, used for determining a feedback control amount according to the lateral control deviation;

[0174] A feedforward control amount determination submodule, used to determine the feedforward control amount according to the lateral control expected data;

[0175] The combining submodule is used to determine the steering assist required torque by combining the feedback control amount and the feedforward control amount.

[0176] In an optional embodiment of the present invention, the second determining module 703 includes:

[0177] A driving force acquisition submodule is used to obtain the current driving force;

[0178] The lever arm determination submodule is used to determine the quotient of the steering assist torque requirement and the current driving force as the kingpin projection point lever arm data.

[0179] In an optional embodiment of the present invention, the third determining module 704 includes:

[0180] A mapping relationship acquisition submodule is used to acquire the mapping relationship between the kingpin projection point force arm data and the suspension height;

[0181] The suspension height determination submodule is used to determine, based on the mapping relationship, the suspension height corresponding to the kingpin projection point force arm data as the target suspension height.

[0182] As for the device embodiment, since it is basically similar to the method embodiment, the description is relatively simple, and the relevant parts can be referred to the partial description of the method embodiment.

[0183] Reference Figure 8 , an embodiment of the present invention further provides a vehicle, comprising:

[0184] A processor 801 and a storage medium 802, wherein the storage medium 802 stores a computer program executable by the processor 801, and when the vehicle is running, the processor 801 executes the computer program to perform the vehicle steering control method as described in any one of the embodiments of the present invention.

[0185] The vehicle steering control method comprises:

[0186] Upon receiving a lateral control request, acquiring vehicle posture data, wherein the lateral control request includes lateral control desired data;

[0187] Determining a steering assist torque requirement according to the vehicle posture data and the lateral control expectation data;

[0188] Determining the kingpin projection point moment arm data according to the steering assist required torque;

[0189] Determining a target suspension height based on the kingpin projection point moment arm data;

[0190] The vehicle suspension is adjusted to the target suspension height to perform vehicle steering.

[0191] Optionally, the method further comprises:

[0192] Calculating a first assist torque according to the kingpin projection point moment arm data;

[0193] In response to the first assist torque being less than the steering assist required torque, determining a vehicle steering axis and a vehicle non-steering axis;

[0194] The driving force of the steering shaft of the vehicle is increased and the driving force of the non-steering shaft of the vehicle is reduced to increase the first assist torque to a second assist torque.

[0195] Optionally, the method further comprises:

[0196] In response to the second assist torque being less than the steering assist request torque, the braking force of the wheels of the vehicle steering shaft is increased to increase the second assist torque to a third assist torque.

[0197] Optionally, the method further comprises:

[0198] In response to the third assist torque being less than the steering assist required torque, determining a rotation direction according to the lateral control desired data;

[0199] determining a yaw torque based on the rotation direction;

[0200] The vehicle is controlled to reach the yaw torque to increase the third assist torque to a fourth assist torque.

[0201] Optionally, the method further comprises:

[0202] generating steering assist abnormality information in response to the fourth assist torque being less than the steering assist required torque;

[0203] The power steering abnormality information is sent.

[0204] Optionally, the method further comprises:

[0205] Get the vehicle steering system status;

[0206] In response to the vehicle steering system being in a power-assist failure state, determining the kingpin projection point moment arm data according to the steering power-assist demand torque is performed.

[0207] Optionally, the step of determining the steering assist required torque according to the vehicle posture data and the lateral control expected data comprises:

[0208] Determining a lateral control deviation between the lateral control desired data and the vehicle posture data;

[0209] determining a feedback control amount according to the lateral control deviation;

[0210] determining a feedforward control amount according to the lateral control desired data;

[0211] The steering assist required torque is determined by combining the feedback control amount and the feedforward control amount.

[0212] Optionally, the step of determining the kingpin projection point arm data according to the steering assist required torque comprises:

[0213] Get the current driving force;

[0214] The quotient of the steering assist torque requirement and the current driving force is determined as the kingpin projection point arm data.

[0215] Optionally, the step of determining the suspension height based on the kingpin projection point moment arm data comprises:

[0216] Obtain the mapping relationship between the kingpin projection point force arm data and the suspension height;

[0217] Based on the mapping relationship, the suspension height corresponding to the kingpin projection point force arm data is determined as the target suspension height.

[0218] The memory may include a random access memory (RAM) or a non-volatile memory, such as at least one disk memory. Optionally, the memory may also be at least one storage device located away from the processor.

[0219] The above-mentioned processor can be a general-purpose processor, including a central processing unit (CPU), a network processor (NP), etc.; it can also be a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components.

[0220] Reference Fig. 9 The embodiment of the present invention further provides a computer-readable storage medium 901, on which a computer program is stored. When the computer program is executed by a processor, the vehicle steering control method as described in any one of the embodiments of the present invention is executed.

[0221] The vehicle steering control method comprises:

[0222] Upon receiving a lateral control request, acquiring vehicle posture data, wherein the lateral control request includes lateral control desired data;

[0223] Determining a steering assist torque requirement according to the vehicle posture data and the lateral control expectation data;

[0224] Determining the kingpin projection point moment arm data according to the steering assist required torque;

[0225] Determining a target suspension height based on the kingpin projection point moment arm data;

[0226] The vehicle suspension is adjusted to the target suspension height to perform vehicle steering.

[0227] Optionally, the method further comprises:

[0228] Calculating a first assist torque according to the kingpin projection point moment arm data;

[0229] In response to the first assist torque being less than the steering assist required torque, determining a vehicle steering axis and a vehicle non-steering axis;

[0230] The driving force of the steering shaft of the vehicle is increased and the driving force of the non-steering shaft of the vehicle is reduced to increase the first assist torque to a second assist torque.

[0231] Optionally, the method further comprises:

[0232] In response to the second assist torque being less than the steering assist request torque, the braking force of the wheels of the vehicle steering shaft is increased to increase the second assist torque to a third assist torque.

[0233] Optionally, the method further comprises:

[0234] In response to the third assist torque being less than the steering assist required torque, determining a rotation direction according to the lateral control desired data;

[0235] determining a yaw torque based on the rotation direction;

[0236] The vehicle is controlled to reach the yaw torque to increase the third assist torque to a fourth assist torque.

[0237] Optionally, the method further comprises:

[0238] generating steering assist abnormality information in response to the fourth assist torque being less than the steering assist required torque;

[0239] The power steering abnormality information is sent.

[0240] Optionally, the method further comprises:

[0241] Get the vehicle steering system status;

[0242] In response to the vehicle steering system being in a power-assist failure state, determining the kingpin projection point moment arm data according to the steering power-assist demand torque is performed.

[0243] Optionally, the step of determining the steering assist required torque according to the vehicle posture data and the lateral control expected data comprises:

[0244] Determining a lateral control deviation between the lateral control desired data and the vehicle posture data;

[0245] determining a feedback control amount according to the lateral control deviation;

[0246] determining a feedforward control amount according to the lateral control desired data;

[0247] The steering assist required torque is determined by combining the feedback control amount and the feedforward control amount.

[0248] Optionally, the step of determining the kingpin projection point arm data according to the steering assist required torque comprises:

[0249] Get the current driving force;

[0250] The quotient of the steering assist torque requirement and the current driving force is determined as the kingpin projection point arm data.

[0251] Optionally, the step of determining the suspension height based on the kingpin projection point moment arm data comprises:

[0252] Obtain the mapping relationship between the kingpin projection point force arm data and the suspension height;

[0253] Based on the mapping relationship, the suspension height corresponding to the kingpin projection point force arm data is determined as the target suspension height.

[0254] The various embodiments in the specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referenced to each other.

[0255] It will be appreciated by those skilled in the art that the embodiments of the present invention may be provided as methods, devices, or computer program products. Therefore, the embodiments of the present invention may take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware. Moreover, the embodiments of the present invention may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program codes.

[0256] The embodiments of the present invention are described with reference to the flowcharts and / or block diagrams of the methods, terminal devices (systems), and computer program products according to the embodiments of the present invention. It should be understood that each process and / or block in the flowchart and / or block diagram, as well as the combination of the processes and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing terminal device to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing terminal device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0257] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing terminal device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce a manufactured product including an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0258] These computer program instructions can also be loaded onto a computer or other programmable data processing terminal device so that a series of operating steps are executed on the computer or other programmable terminal device to produce a computer-implemented process, thereby providing instructions for executing on the computer or other programmable terminal device to implement the process. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0259] The above embodiments are only preferred embodiments for fully illustrating the present invention, and the protection scope of the present invention is not limited thereto. Any equivalent substitution or change made by a person skilled in the art based on the present invention is within the protection scope of the present invention.

Claims

1. A vehicle steering control method, characterized in that: The method comprises: Upon receiving a lateral control request, acquiring vehicle posture data, wherein the lateral control request includes lateral control desired data; Determining a steering assist torque requirement according to the vehicle posture data and the lateral control expectation data; Determining the kingpin projection point moment arm data according to the steering assist required torque; Determining a target suspension height based on the kingpin projection point moment arm data; The vehicle suspension is adjusted to the target suspension height to perform vehicle steering.

2. The method according to claim 1, characterized in that The method further comprises: Calculating a first assist torque according to the kingpin projection point moment arm data; In response to the first assist torque being less than the steering assist required torque, determining a vehicle steering axis and a vehicle non-steering axis; The driving force of the steering shaft of the vehicle is increased and the driving force of the non-steering shaft of the vehicle is reduced to increase the first assist torque to a second assist torque.

3. The method according to claim 2, characterized in that The method further comprises: In response to the second assist torque being less than the steering assist request torque, the braking force of the wheels of the vehicle steering shaft is increased to increase the second assist torque to a third assist torque.

4. The method according to claim 3, characterized in that The method further comprises: In response to the third assist torque being less than the steering assist required torque, determining a rotation direction according to the lateral control desired data; determining a yaw torque based on the rotation direction; The vehicle is controlled to reach the yaw torque to increase the third assist torque to a fourth assist torque.

5. The method according to claim 4, characterized in that The method further comprises: generating steering assist abnormality information in response to the fourth assist torque being less than the steering assist required torque; The power steering abnormality information is sent.

6. The method according to claim 1, characterized in that The method further comprises: Get the vehicle steering system status; In response to the vehicle steering system being in a power-assist failure state, determining the kingpin projection point moment arm data according to the steering power-assist demand torque is performed.

7. The method according to claim 1, characterized in that The step of determining the steering assist required torque according to the vehicle posture data and the lateral control expected data comprises: Determining a lateral control deviation between the lateral control desired data and the vehicle posture data; determining a feedback control amount according to the lateral control deviation; determining a feedforward control amount according to the lateral control desired data; The steering assist required torque is determined by combining the feedback control amount and the feedforward control amount.

8. The method according to claim 1, characterized in that The step of determining the kingpin projection point arm data according to the steering assist required torque comprises: Get the current driving force; The quotient of the steering assist torque requirement and the current driving force is determined as the kingpin projection point arm data.

9. The method according to claim 1, characterized in that: The step of determining the suspension height based on the kingpin projection point moment arm data comprises: Obtain the mapping relationship between the kingpin projection point force arm data and the suspension height; Based on the mapping relationship, the suspension height corresponding to the kingpin projection point force arm data is determined as the target suspension height.

10. A vehicle steering control device, characterized in that: The device comprises: A first acquisition module, configured to acquire vehicle posture data when receiving a lateral control request, wherein the lateral control request includes lateral control expected data; A first determination module, configured to determine a steering assist torque requirement according to the vehicle posture data and the lateral control expectation data; A second determination module is used to determine the kingpin projection point arm data according to the steering assist required torque; A third determination module, configured to determine the suspension height based on the kingpin projection point moment arm data; The adjustment module is used to adjust the vehicle suspension to the suspension height so as to perform vehicle steering.

11. A vehicle, characterized in that: The invention comprises a processor, a memory and a computer program stored in the memory and capable of running on the processor, wherein when the computer program is executed by the processor, the steps of the vehicle steering control method according to any one of claims 1 to 9 are implemented.

12. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the steps of the vehicle steering control method according to any one of claims 1 to 9 are implemented.

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