Vehicle steering assist system and control unit thereof

Abstract

A vehicle steering assist system (100) and a control unit (20) thereof. The control unit (20) comprises: an acquisition module (21) configured to acquire yaw rate parameters and steering wheel angle parameters of a vehicle; a determination module (21) configured to determine, on the basis of the acquired yaw rate parameters and the steering wheel angle parameters, whether a driver of the vehicle desires to increase or decrease a turning radius of the vehicle; a judgement module (23) configured to determine whether the current state of the vehicle satisfies one of a plurality of predetermined steering working conditions; and a decision-making module (24) configured to make a steering assist decision on the basis of the change in the turning radius desired by the driver and the current steering working condition of the vehicle. The vehicle steering assist system (100) and the control unit (20) thereof can cope with flexibly-changing vehicle steering requirements.

Description

Vehicle steering assist system and its control unit Technical Field

[0001] The present invention generally relates to the technical field of vehicle steering control, and in particular to a vehicle steering assist system and a control unit thereof. Background Art

[0002] Conventional vehicle steering assistance technologies typically use mechanical hydraulic power or electronic power steering to help drivers achieve easy steering control. However, existing steering assistance technologies are still unable to effectively cope with the ever-changing vehicle steering requirements.

[0003] Summary of the Invention

[0004] In this context, the present invention aims to provide a solution for vehicle steering assistance, which can achieve smooth control of target vehicle steering (eg, the changing trend of the vehicle turning radius desired by the driver).

[0005] According to one embodiment of the present invention, a control unit for a vehicle steering assist system is provided, which includes: an acquisition module configured to acquire a yaw rate parameter and a steering wheel angle parameter of the vehicle; a determination module configured to determine whether the driver of the vehicle expects to increase or decrease the vehicle turning radius based on the acquired yaw rate parameter and the steering wheel angle parameter; a judgment module configured to determine whether the current state of the vehicle satisfies: the driving torque directions of the front axle inner wheel, the front axle outer wheel, the rear axle inner wheel and the rear axle outer wheel are all forward; and a decision module configured to: when the determination module determines that the driver expects to increase the vehicle turning radius and the determination result of the judgment module is affirmative, decide to execute one or more of the following multiple steering assist strategies: 1) when the front axle slip rate does not reach the front axle target slip rate, maintain or increase the driving torque of the front axle, and when the front axle slip rate reaches the front axle target slip rate, maintain or increase the front axle target slip rate; 2) when the rear axle slip rate and 3) providing a torque in a direction opposite to the driving torque of the at least one outer wheel to at least one outer wheel; and when the determination module determines that the driver wants to reduce the vehicle turning radius and the determination result of the judgment module is affirmative, a decision is made to execute one or more of the following steering assist strategies: 1) when the front axle slip ratio does not reach the front axle target slip ratio, maintain or reduce the front axle driving torque, and when the front axle slip ratio reaches the front axle target slip ratio, maintain or reduce the front axle target slip ratio; 2) when the rear axle slip ratio does not reach the rear axle target slip ratio, reduce the rear axle driving torque, and when the rear axle slip ratio reaches the rear axle target slip ratio, maintain or increase the rear axle target slip ratio; and 3) providing a torque in a direction opposite to the driving torque of the at least one inner wheel to at least one inner wheel.

[0006] According to one embodiment of the present invention, a control unit for a vehicle steering assist system is provided, comprising: an acquisition module configured to acquire a yaw rate parameter and a steering wheel angle parameter of the vehicle; a determination module configured to determine, based on the acquired yaw rate parameter and steering wheel angle parameter, whether the vehicle driver desires to increase or decrease the vehicle turning radius; a judgment module configured to determine whether the current state of the vehicle satisfies: the driving torque directions of the front axle inner wheel, the front axle outer wheel, the rear axle inner wheel, and the rear axle outer wheel are all forward; and a decision module configured to: When the determination module determines that the driver wants to increase the turning radius of the vehicle and the determination result of the judgment module is affirmative, the decision is to execute one or more of the following steering assist strategies: 1) when the slip ratios of the front axle inner wheel and the front axle outer wheel have not reached the front axle target slip ratio, maintain or increase the front axle driving torque, and when the slip ratio of at least one of the front axle inner wheel and the front axle outer wheel reaches the front axle target slip ratio, maintain or increase the front axle target slip ratio; 2) when the slip ratios of the rear axle inner wheel and the rear axle outer wheel have not reached the rear axle target slip ratio, maintain or increase the rear axle driving torque, and when the slip rate of at least one of the rear axle inner wheel and the rear axle outer wheel reaches the rear axle target slip rate, reduce the rear axle target slip rate; and 3) provide a torque in the opposite direction of the driving torque of the at least one outer wheel to at least one outer wheel; and when the determination module determines that the driver wants to reduce the vehicle turning radius and the determination result of the judgment module is affirmative, decide to execute one or more of the following multiple steering assist strategies: 1) when the slip rate of both the front axle inner front wheel and the front axle outer wheel does not reach the front axle target slip rate, maintain The invention relates to a method for controlling the rotation of the front axle and the rear axle wheel to control the vehicle's rotational direction. The method comprises the following steps: 1) maintaining or reducing the front axle driving torque, and maintaining or reducing the front axle target slip ratio when the slip ratio of at least one of the front axle inner front wheel and the front axle outer wheel reaches the front axle target slip ratio; 2) reducing the rear axle driving torque when the slip ratio of both the rear axle inner wheel and the rear axle outer wheel does not reach the rear axle target slip ratio, and maintaining or increasing the rear axle target slip ratio when the slip ratio of at least one of the rear axle inner wheel and the rear axle outer wheel reaches the rear axle target slip ratio; and 3) providing a torque to at least one inside wheel in a direction opposite to the driving torque of the at least one inside wheel.

[0007] According to one embodiment of the present invention, a control unit for a vehicle steering assist system is provided, which includes: an acquisition module configured to acquire a yaw rate parameter and a steering wheel angle parameter of the vehicle; a determination module configured to determine whether the vehicle driver desires to increase or decrease the vehicle turning radius based on the acquired yaw rate parameter and the steering wheel angle parameter; a judgment module configured to determine whether the current state of the vehicle satisfies: the driving torque directions of the front axle inner wheel and the front axle outer wheel are both forward, and the driving torque directions of the rear axle inner wheel and the rear axle outer wheel are both backward; and a decision module configured to: when the determination module determines that the driver desires to increase the vehicle turning radius and the determination result of the judgment module is affirmative, decide to execute one or more of the following steering assist strategies: 1) when the front axle slip rate does not reach the front axle target slip rate, maintain or increase the front axle driving torque, and when the front axle slip rate reaches the front axle target slip rate, maintain or reduce the front axle target slip rate; 2) when the rear axle slip rate does not reach the rear axle target slip rate, maintain or reduce 1) providing a low rear axle driving torque, and when the rear axle slip rate reaches the rear axle target slip rate, reducing the rear axle target slip rate; 2) providing a torque to the front and rear outer wheels in the opposite direction of the driving torque of the front axle outer wheels; 3) providing a torque to the rear axle inner wheels in the opposite direction of the driving torque of the rear axle inner wheels; and 4) providing a torque to the rear axle inner wheels in the opposite direction of the driving torque of the rear axle inner wheels; and when the determination module determines that the driver wants to reduce the vehicle turning radius and the determination result of the judgment module is positive, deciding to execute one or more of the following multiple steering assist strategies: 1) when the front axle slip rate does not reach the front axle The present invention provides the following three methods: 1) when the front axle slip rate reaches the target slip rate, maintain or reduce the front axle driving torque, and when the front axle slip rate reaches the front axle target slip rate, maintain or increase the front axle target slip rate; 2) when the rear axle slip rate does not reach the rear axle target slip rate, increase the rear axle driving torque, and when the rear axle slip rate reaches the rear axle target slip rate, maintain or increase the rear axle target slip rate; 3) provide a torque in the opposite direction to the driving torque of the inner wheel of the front axle; 4) provide a torque in the opposite direction to the driving torque of the outer wheel of the rear axle to the outer wheel of the rear axle.

[0008] According to one embodiment of the present invention, a control unit for a vehicle steering assist system is provided, which includes: an acquisition module configured to acquire a yaw rate parameter and a steering wheel angle parameter of the vehicle; a determination module configured to determine whether the vehicle driver desires to increase or decrease the vehicle turning radius based on the acquired yaw rate parameter and the steering wheel angle parameter; a judgment module configured to judge whether the current state of the vehicle satisfies: the driving torque directions of the front axle inner wheel and the front axle outer wheel are both forward, and the driving torque directions of the rear axle inner wheel and the rear axle outer wheel are both backward; and a decision module configured to: in the determination module When the block determines that the driver wants to increase the turning radius of the vehicle and the determination result of the judgment module is affirmative, the decision is to execute one or more of the following steering assist strategies: 1) when the slip ratios of the front axle inner wheel and the front axle outer wheel have not reached the front wheel target slip ratio, the front axle drive torque is maintained or increased, and when the slip ratio of at least one of the front axle inner wheel and the front axle outer wheel reaches the front axle target slip ratio, the front axle target slip ratio is maintained or reduced; 2) when the slip ratios of the rear axle inner wheel and the rear axle outer wheel have not reached the rear axle target slip ratio, the rear axle drive torque is maintained or reduced, and when the rear axle inner wheel and the rear axle When the slip ratio of at least one of the outer wheels reaches the rear axle target slip ratio, the rear axle target slip ratio is reduced; 3) a torque in the opposite direction to the driving torque of the front axle outer wheel is provided to the front axle outer wheel; 4) a torque in the opposite direction to the driving torque provided to the rear axle inner wheel is provided to the rear axle inner wheel; and when the determination module determines that the driver wants to reduce the vehicle turning radius and the determination result of the judgment module is affirmative, a decision is made to execute one or more of the following steering assist strategies: 1) when the slip ratios of both the front axle inner wheel and the front axle outer wheel do not reach the front axle target slip ratio, maintain or reduce the front axle driving torque , and when the slip rate of at least one of the front axle inner wheel and the front axle outer wheel reaches the front axle target slip rate, maintain or increase the front axle target slip rate; 2) when the slip rate of the rear axle outer wheel and the rear axle inner wheel has not reached the rear axle target slip rate, increase the rear axle driving torque, and when the slip rate of at least one of the rear axle inner wheel and the rear axle outer wheel reaches the rear axle target slip rate, maintain or increase the rear axle target slip rate; 3) provide the front axle inner wheel with a torque in the opposite direction of the driving torque of the front axle inner wheel; 4) provide the rear axle outer wheel with a torque in the opposite direction of the driving torque of the rear axle outer wheel.

[0009] According to one embodiment of the present invention, a control unit for a vehicle steering assist system is provided, which includes: an acquisition module configured to acquire a yaw rate parameter and a steering wheel angle parameter of the vehicle; a determination module configured to determine whether the vehicle driver desires to increase or decrease the vehicle turning radius based on the acquired yaw rate parameter and the steering wheel angle parameter; a judgment module configured to determine whether the current state of the vehicle satisfies: the driving torque directions of the front axle inner wheel and the front axle outer wheel are both backward, and the driving torque directions of the rear axle inner wheel and the rear axle outer wheel are both forward; and a decision module configured to: when the determination module determines that the driver desires to increase the vehicle turning radius and the determination result of the judgment module is affirmative, decide to execute one or more of the following steering assist strategies: 1) when the front axle slip rate does not reach the front axle target slip rate, maintain or reduce the front axle driving torque, and when the front axle slip rate reaches the front axle target slip rate, increase the front axle target slip rate; 2) when the rear axle slip rate does not reach the rear axle target slip rate, maintain or increase the rear axle target slip rate axle driving torque, and when the rear axle slip rate reaches the rear axle target slip rate, reduce the rear axle target slip rate; 3) provide a driving torque to the inner wheel of the front axle in the opposite direction of the driving torque of the inner wheel of the front axle; 4) provide a torque to the outer wheel of the rear axle in the opposite direction of the driving torque of the outer wheel of the rear axle; and when the determination module determines that the driver wants to reduce the vehicle turning radius and the determination result of the judgment module is positive, decide to execute one or more of the following multiple steering assist strategies: 1) the current axle slip rate does not reach the front axle target slip rate axle target slip rate, maintain or increase the front axle driving torque, and when the front axle slip rate reaches the front axle target slip rate, reduce the front axle target slip rate; 2) when the rear axle slip rate does not reach the rear axle target slip rate, maintain or reduce the rear axle driving torque, and when the rear axle slip rate reaches the rear axle target slip rate, increase the rear axle target slip rate; 3) provide a driving torque in the opposite direction to the driving torque of the outer wheel of the front axle; 4) provide a torque in the opposite direction to the driving torque of the inner wheel of the rear axle to the inner wheel of the rear axle.

[0010] According to one embodiment of the present invention, a control unit for a vehicle steering assist system is provided, comprising: an acquisition module configured to acquire a yaw rate parameter and a steering wheel angle parameter of the vehicle; a determination module configured to determine, based on the acquired yaw rate parameter and the steering wheel angle parameter, whether the vehicle driver desires to increase or decrease the vehicle turning radius; a judgment module configured to determine whether the current state of the vehicle satisfies: the driving torque directions of the front axle inner wheel and the front axle outer wheel are both backward, and the driving torque directions of the rear axle inner wheel and the rear axle outer wheel are both forward; and a decision module configured to: after determining When the module determines that the driver wants to increase the turning radius of the vehicle and the determination result of the judgment module is affirmative, the decision is to execute one or more of the following steering assist strategies: 1) when the slip ratios of the front axle inner wheel and the front axle outer wheel do not reach the front axle target slip ratio, maintain or reduce the front axle drive torque, and when the slip ratio of at least one of the front axle inner wheel and the front axle outer wheel reaches the front axle target slip ratio, increase the front axle target slip ratio; 2) when the slip ratios of the rear axle inner wheel and the rear axle outer wheel do not reach the rear axle target slip ratio, maintain or increase the rear axle drive torque, and when the rear axle inner wheel and the rear axle outer wheel reach the rear axle target slip ratio, maintain or increase the rear axle drive torque. When the slip ratio of at least one of the side wheels reaches the rear axle target slip ratio, the rear axle target slip ratio is reduced; 3) a driving torque in the opposite direction to the driving torque of the front axle inner wheel is provided to the front axle inner wheel; 4) a torque in the opposite direction to the driving torque of the rear axle outer wheel is provided to the rear axle outer wheel; and when the determination module determines that the driver wants to reduce the vehicle turning radius and the determination result of the judgment module is affirmative, a decision is made to execute one or more of the following steering assist strategies: 1) when the slip ratios of both the front axle inner wheel and the front axle outer wheel do not reach the front wheel target slip ratio, maintain or increase the front axle driving torque , and when the slip rate of at least one of the front axle inner wheel and the front axle outer wheel reaches the front axle target slip rate, reduce the front axle target slip rate; 2) when the slip rate of the rear axle inner wheel and the rear axle outer wheel has not reached the rear axle target slip rate, maintain or reduce the rear axle driving torque, and when the slip rate of at least one of the rear axle inner wheel and the rear axle outer wheel reaches the rear axle target slip rate, increase the rear axle target slip rate; 3) provide a driving torque in the opposite direction to the driving torque of the front axle outer wheel to the front axle outer wheel; 4) provide a torque in the opposite direction to the driving torque of the rear axle inner wheel to the rear axle inner wheel.

[0011] According to one embodiment of the present invention, a control unit for a vehicle steering assist system is provided, comprising: an acquisition module configured to acquire a yaw rate parameter and a steering wheel angle parameter of the vehicle; a determination module configured to determine, based on the acquired yaw rate parameter and the steering wheel angle parameter, whether the vehicle driver desires to increase or decrease the vehicle turning radius; a judgment module configured to determine whether the current state of the vehicle satisfies: the driving torque directions of the front axle inner wheel, the front axle outer wheel, the rear axle inner wheel, and the rear axle outer wheel are all backward; and a decision module configured to: when the determination module determines that the driver desires to increase the vehicle turning radius and the determination result of the judgment module is affirmative, decide to execute one or more of the following steering assist strategies: 1) when the front axle slip ratio does not reach the front axle target slip ratio, maintain or reduce the front axle driving torque, and when the front axle slip ratio reaches the front axle target slip ratio, increase the front axle target slip ratio; 2) When the rear axle slip rate does not reach the rear axle target slip rate, maintain or reduce the rear axle driving torque, and when the rear axle slip rate reaches the rear axle target slip rate, reduce the front axle target slip rate; 3) provide a driving torque in the opposite direction of the driving torque of the at least one inner wheel to at least one inner wheel; when the determination module determines that the driver wants to reduce the vehicle turning radius and the judgment result of the judgment module is affirmative, decide to execute one or more of the following steering assist strategies: 1) when the front axle slip rate does not reach the front axle target slip rate, maintain or increase the front axle driving torque, and when the front axle slip rate reaches the front axle target slip rate, reduce the front axle target slip rate; 2) when the rear axle slip rate does not reach the rear axle target slip rate, maintain or increase the front axle driving torque, and when the rear axle slip rate reaches the rear axle target slip rate, increase the rear axle target slip rate; 3) provide a torque in the opposite direction of the driving torque of the at least one outer wheel to at least one outer wheel.

[0012] According to one embodiment of the present invention, a control unit for a vehicle steering assist system is provided, comprising: an acquisition module configured to acquire a yaw rate parameter and a steering wheel angle parameter of the vehicle; a determination module configured to determine, based on the acquired yaw rate parameter and the steering wheel angle parameter, whether the vehicle driver desires to increase or decrease the vehicle turning radius; a judgment module configured to determine whether the current state of the vehicle satisfies: the driving torque directions of the front axle inner wheel, the front axle outer wheel, the rear axle inner wheel, and the rear axle outer wheel are all backward; and a decision module configured to determine whether the vehicle driver desires to increase or decrease the vehicle turning radius based on the acquired yaw rate parameter and the steering wheel angle parameter; a judgment module configured to determine whether the current state of the vehicle satisfies: the driving torque directions of the front axle inner wheel, the front axle outer wheel, the rear axle inner wheel, and the rear axle outer wheel are all backward; and The invention is configured to: when the determination module determines that the driver desires to increase the turning radius of the vehicle and the determination result of the judgment module is affirmative, decide to execute one or more of the following steering assist strategies: 1) when the slip ratios of the front axle inner wheel and the front axle outer wheel have not reached the front axle target slip ratio, maintain or reduce the front axle driving torque, and when the slip ratio of at least one of the front axle inner wheel and the front axle outer wheel reaches the front axle target slip ratio, increase the front axle target slip ratio; 2) when the slip ratios of the rear axle inner wheel and the rear axle outer wheel have not reached the rear axle target slip ratio , maintain or reduce the rear axle driving torque, and when the slip rate of at least one of the rear axle inner wheel and the rear axle outer wheel reaches the rear axle target slip rate, reduce the front axle target slip rate; 3) provide a torque opposite to the driving torque of the at least one inner wheel to the at least one inner wheel; when the determination module determines that the driver wants to reduce the vehicle turning radius and the determination result of the judgment module is affirmative, decide to execute one or more of the following multiple steering assist strategies: 1) when the slip rate of the front axle inner road and the front axle outer wheel does not reach the front axle target slip rate , maintain or increase the front axle driving torque, and when the slip ratio of at least one of the front axle inner wheel and the front axle outer wheel reaches the front axle target slip ratio, reduce the front axle target slip ratio; 2) when the slip ratios of the rear axle inner wheel and the rear axle outer wheel have not reached the rear axle target slip ratio, maintain or increase the front axle driving torque, and when the slip ratio of at least one of the rear axle inner wheel and the rear axle outer wheel reaches the rear axle target slip ratio, increase the rear axle target slip ratio; 3) provide a torque to at least one outer wheel in a direction opposite to the driving torque of the at least one outer wheel.

[0013] In the examples of the above embodiments, the yaw rate parameters include: a yaw rate ratio between a sensor yaw rate obtained based on sensor measurement results and a calculated yaw rate obtained based on calculation of the driver's operation of the steering wheel, an increase rate of the sensor yaw rate, and a decrease rate of the sensor yaw rate; and wherein the steering wheel angle parameters include: a steering wheel angle, a steering wheel angle increase rate, and a steering wheel angle decrease rate.

[0014] In the embodiments of the above embodiments, determining whether the vehicle driver intends to increase or decrease the vehicle turning radius based on the acquired yaw rate parameter and steering wheel angle parameter includes: - determining that the driver intends to decrease the vehicle turning radius when the steering wheel angle increase rate is greater than a steering wheel angle increase rate threshold and the steering wheel angle is greater than the steering wheel angle threshold; - determining that the driver intends to increase the vehicle turning radius when the steering wheel angle decrease rate is greater than the steering wheel angle decrease rate threshold and the steering wheel angle is less than the steering wheel angle threshold; - determining that the driver intends to increase the vehicle turning radius when the yaw rate ratio is greater than 1 and less than a first yaw rate ratio threshold , and the steering wheel angle increase rate is greater than the steering wheel angle increase rate threshold, it is determined that the vehicle turning radius is reduced; - when the yaw rate ratio is greater than 1 and the steering wheel angle decrease rate is greater than the steering wheel angle decrease rate threshold, it is determined that the driver desires to increase the vehicle turning radius; - when the yaw rate ratio is less than 1 and the steering wheel angle increase rate is greater than the steering wheel angle increase rate threshold, it is determined that the vehicle turning radius is reduced; - when the yaw rate ratio is less than 1 and greater than a second yaw rate ratio threshold, and the steering wheel angle decrease rate is greater than the steering wheel angle decrease rate threshold, it is determined that the vehicle turning radius is increased.

[0015] In the examples of the above embodiments, the determination module is further configured to determine the degree of increase or decrease of the vehicle turning radius desired by the vehicle driver based on the acquired yaw rate parameter and steering wheel angle parameter.

[0016] In the embodiments of the above embodiments, determining the degree of increase or decrease in the vehicle turning radius expected by the vehicle driver based on the acquired yaw rate parameter and steering wheel angle parameter includes, for the same vehicle speed: when the steering wheel angle is greater than the steering wheel angle threshold, the greater the rate of increase of the steering wheel angle, the greater the degree of decrease in the vehicle turning radius expected by the driver; and when the steering wheel angle is less than the steering wheel angle threshold, the greater the rate of decrease of the steering wheel angle, the greater the degree of increase in the vehicle turning radius expected by the driver.

[0017] In the embodiments of the above embodiments, the decision to execute one or more of the multiple steering assist strategies includes: as the driver's desired turning radius increases or decreases more, the following are selected to be executed in sequence: - slip rate control strategy; - reverse torque control strategy; and - slip rate control strategy and reverse torque control strategy.

[0018] In the embodiments of the above embodiments, the decision to execute one or more of the multiple steering assist strategies includes selecting in sequence as the vehicle stability decreases: - slip rate control strategy; - reverse torque control strategy; and - slip rate control strategy and reverse torque control strategy.

[0019] In the examples of the above embodiments, when the turning radius of the vehicle is reduced, the degree of stability of the vehicle decreases in the following situations: - a yaw rate ratio between a sensor yaw rate obtained based on a sensor measurement result and a calculated yaw rate obtained based on calculation of the driver's operation of the steering wheel is greater than 1 and less than a first yaw rate ratio threshold, and a rate of decrease of the sensor yaw rate is greater than a yaw rate decrease rate threshold; - the yaw rate ratio is greater than 1 and less than the first yaw rate ratio threshold, and a rate of decrease of the sensor yaw rate is less than the yaw rate decrease rate threshold; - the yaw rate ratio is greater than 1 and less than the first yaw rate ratio threshold, and a rate of increase of the sensor yaw rate is less than the yaw rate increase rate threshold; - the The yaw rate ratio is greater than 1 and less than a first yaw rate ratio threshold, and the rate of increase of the sensor yaw rate is greater than the yaw rate increase rate threshold; - the yaw rate ratio is greater than 1 and greater than the first yaw rate ratio threshold, and the rate of decrease of the sensor yaw rate is greater than the yaw rate decrease rate threshold; - the yaw rate ratio is greater than 1 and greater than the first yaw rate ratio threshold, and the rate of decrease of the sensor yaw rate is less than the yaw rate decrease rate threshold; - the yaw rate ratio is greater than 1 and greater than the first yaw rate ratio threshold, and the rate of increase of the sensor yaw rate is less than the yaw rate increase rate threshold; - the yaw rate ratio is greater than 1 and greater than the first yaw rate ratio threshold, and the rate of increase of the sensor yaw rate is greater than the yaw rate increase rate threshold.

[0020] In the examples of the above embodiments, when the turning radius of the vehicle is increased, the degree of stability of the vehicle decreases in the following situations: - a yaw rate ratio between a sensor yaw rate obtained based on a sensor measurement result and a calculated yaw rate obtained based on calculation of the driver's operation of the steering wheel is less than 1 and greater than a second yaw rate ratio threshold, and an increase rate of the sensor yaw rate is greater than a yaw rate increase rate threshold; - the yaw rate ratio is less than 1 and greater than the second yaw rate ratio threshold, and an increase rate of the sensor yaw rate is less than the yaw rate increase rate threshold; - the yaw rate ratio is less than 1 and greater than the second yaw rate ratio threshold, and a decrease rate of the sensor yaw rate is less than the yaw rate decrease rate threshold; - the yaw rate ratio is less than 1 and greater than the second yaw rate ratio threshold, and a decrease rate of the sensor yaw rate is less than the yaw rate decrease rate threshold; The yaw rate ratio is less than 1 and greater than a second yaw rate ratio threshold, and the rate of decrease of the sensor yaw rate is greater than the yaw rate decrease rate threshold; - the yaw rate ratio is less than 1 and less than the second yaw rate ratio threshold, and the rate of increase of the sensor yaw rate is greater than the yaw rate increase rate threshold; - the yaw rate ratio is less than 1 and less than the second yaw rate ratio threshold, and the rate of increase of the sensor yaw rate is less than the yaw rate increase rate threshold; - the yaw rate ratio is less than 1 and less than the second yaw rate ratio threshold, and the rate of decrease of the sensor yaw rate is less than the yaw rate decrease rate threshold; - the yaw rate ratio is less than 1 and less than the second yaw rate ratio threshold, and the rate of decrease of the sensor yaw rate is greater than the yaw rate decrease rate threshold.

[0021] According to one embodiment of the present invention, a vehicle steering assist system is provided, which includes: a sensor unit configured to sense and / or receive a yaw rate parameter and a steering wheel angle parameter of a vehicle; a control unit as described above, configured to decide a steering assist strategy based on the yaw rate parameter and the steering wheel angle parameter of the vehicle and corresponding threshold values; and an actuator unit, configured to execute the decided steering assist strategy through one or more of slip rate control, braking control and drive control.

[0022] The foregoing provides a summary of the major aspects of the present invention to facilitate a basic understanding of these aspects. This summary is not intended to describe key or important elements of all aspects of the present invention, nor is it intended to limit the scope of any or all aspects of the present invention. The purpose of this summary is to provide some implementations of these aspects in a simplified form, serving as a prelude to the detailed description that will be provided later. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The technical solution of the present invention will become more apparent from the following detailed description in conjunction with the accompanying drawings. It should be understood that these drawings are only for illustrative purposes and are not intended to limit the scope of protection of the present invention.

[0024] FIG1 is a schematic block diagram of a vehicle steering assist system according to an embodiment of the present invention.

[0025] 2-3 are flow charts of some examples of a vehicle steering assist method according to an embodiment of the present invention, which are applicable to vehicle steering condition 1.

[0026] 4-5 are flow charts of some examples of a vehicle steering assist method according to another embodiment of the present invention, which are applicable to a second vehicle steering condition.

[0027] 6-7 are flow charts of some examples of a vehicle steering assist method according to yet another embodiment of the present invention, which are applicable to vehicle steering condition three.

[0028] 8-9 are flow charts of some examples of a vehicle steering assist method according to yet another embodiment of the present invention, which are applicable to vehicle steering condition four. DETAILED DESCRIPTION

[0029] An embodiment of the present invention relates to a solution for vehicle steering assistance, which can combine slip rate control and reverse torque control to achieve vehicle steering assistance under various steering conditions. Therefore, whether it is reducing the vehicle turning radius or increasing the vehicle turning radius, or reducing or increasing the vehicle turning radius to different degrees, a smooth control solution is provided.

[0030] In an embodiment of the present invention, reverse torque includes: 1) a driving torque provided by the vehicle's motor that is opposite to the current direction of travel (hereinafter referred to as "reverse torque provided by the motor"); and 2) a braking torque provided by the vehicle's brakes that is opposite to the current driving torque (hereinafter referred to as "reverse torque provided by the brakes"). Therefore, in an embodiment of the present invention, reverse torque control can be achieved by manipulating the vehicle's motor to cause the motor to provide reverse torque, or by manipulating the vehicle's brakes to cause an actuator to provide reverse torque.

[0031] According to an embodiment of the present invention, on the basis of combining slip rate control with reverse torque control, the range of change of the vehicle's yaw rate can be widened, and the change of the vehicle's turning radius desired by the driver can be more finely distinguished and realized, thereby having the advantages of control flexibility and vehicle response agility.

[0032] In an embodiment of the present invention, slip control and / or reverse torque control can be selected based on the degree of increase or decrease in the vehicle turning radius desired by the driver, so that the vehicle can achieve the change in the vehicle turning radius desired by the driver in a more stable state and with a faster response speed.

[0033] In an embodiment of the present invention, slip ratio control and / or reverse torque control may be selectively executed according to the vehicle's stability level, thereby enabling a steering assist strategy that fully responds to the vehicle's current stability level while achieving the driver's desired change in vehicle turning radius.

[0034] In the embodiments of the present invention, a vehicle is a four-wheeled vehicle, that is, a vehicle including a left front wheel and a right front wheel coupled to the front axle of the vehicle, and a left rear wheel and a right rear wheel coupled to the rear axle of the vehicle. In addition, in order to clearly express the relationship between each wheel and the steering, in the embodiments of the present invention, the four wheels are expressed as: the front axle inner wheel, the front axle outer wheel, the rear axle inner wheel, and the rear axle outer wheel. It is understood that "inside" refers to the inside of the turn. For example, if the vehicle turns left, the left wheel is the inside wheel. "Outside" refers to the outside of the turn. For example, if the vehicle turns left, the right wheel is the outside wheel.

[0035] It is worth noting that various thresholds are employed in the embodiments of the present invention, such as a first yaw rate ratio threshold, a second yaw rate ratio threshold, a yaw rate increase rate threshold, a yaw rate decrease rate threshold, a steering wheel angle threshold, a steering wheel angle increase rate threshold, a steering wheel angle decrease rate threshold, and the like. These thresholds are predetermined, for example, based on actual vehicle test results and / or models. The present invention does not limit their specific values.

[0036] Furthermore, these thresholds can also be customized for a vehicle user (e.g., the OEM or the vehicle driver) based on their historical preference data, thereby ensuring that the vehicle's steering style meets the vehicle user's preferences. It should be understood that the customized thresholds that meet the vehicle user's preferences are determined to fully ensure the vehicle's completeness during cornering. Therefore, these customized thresholds should be understood as meeting the vehicle user's preferences to a certain extent without sacrificing vehicle safety.

[0037] The specific embodiments of the present invention are described below with reference to the accompanying drawings.

[0038] FIG1 shows a vehicle steering assist system 100 according to an embodiment of the present invention, which is provided on a vehicle. As shown in FIG1 , the steering assist system 100 includes a sensor unit 10 , a control unit 20 , and an actuator unit 30 .

[0039] The sensor unit 10 is used to provide information related to the vehicle's steering state, such as the vehicle's yaw rate parameter, steering wheel angle parameter, and slip rate parameter. Yaw rate parameters include: sensor yaw rate (the yaw rate measured by a yaw rate sensor, also known as measured yaw rate, which reflects the actual yaw rate of the vehicle body); calculated yaw rate (the yaw rate calculated based on the driver's steering wheel operation, which reflects the driver's desired yaw rate of the vehicle body); the yaw rate ratio between the sensor yaw rate and the calculated yaw rate (this ratio reflects the relationship between the actual yaw rate of the vehicle body and the driver's desired yaw rate, for example, whether the two are consistent or which is greater); and the rate of change of the sensor yaw rate, i.e., the rate of increase and decrease of the sensor yaw rate. Steering wheel angle parameters include the steering wheel angle and the rate of change of the steering wheel angle, i.e., the rate of increase and decrease of the steering wheel angle. Slip rate parameters may include the slip rate of the axle and the slip rate of the wheel.

[0040] It will be appreciated that information related to the vehicle's steering state can be obtained directly based on sensor measurements or by calculating sensor measurements. For example, the steering wheel angle can be directly obtained based on the steering wheel angle sensor's measurements. The wheel slip rate can be obtained by calculating the ratio of the speed difference between the vehicle speed and the wheel speed to the vehicle speed.

[0041] In one embodiment, the sensor unit 10 may include sensors for sensing parameters such as vehicle speed, wheel speed, and steering wheel angle, and may also include sensors for receiving information related to the vehicle's steering state, for example, receiving information related to the vehicle's steering state from an edge cloud or a cloud server via V2X communication.

[0042] The control unit 20 is in communication with the sensor unit 10 to receive information related to vehicle steering. Based on the received information, the control unit 20 determines the driver's expectation of a change in the vehicle's turning radius, for example, whether to increase or decrease the vehicle's turning radius, the degree of increase, and the degree of decrease. In addition, multiple vehicle steering conditions are predetermined based on the direction of the current driving torque of each wheel. The multiple vehicle steering conditions include: 1) Steering condition 1: the driving torque direction of the front axle inner wheel, the front axle outer wheel, the rear axle inner wheel, and the rear axle outer wheel are all forward; 2) Steering condition 2: the driving torque direction of the front axle inner wheel and the front axle outer wheel are all forward, and the driving torque direction of the rear axle inner wheel and the rear axle outer wheel are all backward; 3) Steering condition 3: the driving torque direction of the front axle inner wheel and the front axle outer wheel are all backward, and the driving torque direction of the rear axle inner wheel and the rear axle outer wheel are all forward; and 4) Steering condition 4: the driving torque direction of the front axle inner wheel, the front axle outer wheel, the rear axle inner wheel, and the rear axle outer wheel are all backward.

[0043] It should be understood that "forward" and "backward" are defined in relation to the direction of travel of the vehicle. That is, "forward" refers to the same direction as the direction of travel of the vehicle. "Backward" refers to the opposite direction to the direction of travel of the vehicle.

[0044] Next, the control unit 20 determines whether the vehicle's current state falls within one of the multiple steering conditions. Furthermore, the control unit 20 determines a corresponding steering assist strategy based on the driver's desired turning radius change and the current steering condition. This steering assist strategy involves using slip ratio control and / or reverse torque control to achieve the desired turning radius change under the current steering condition, while ensuring vehicle stability during steering.

[0045] In one embodiment, the control unit 20 includes an acquisition module 21, a determination module 22, a judgment module 23, and a decision module 24. It should be understood that the naming of these modules is functional and is not intended to limit their implementation or physical location. For example, these modules can be implemented on the same chip or circuit, or on different chips or circuits.

[0046] The control unit 20 may be implemented in hardware, software, or a combination of software and hardware. For portions implemented in hardware, they may be implemented in one or more application-specific integrated circuits (ASICs), digital signal processors (DSPs), digital signal processing devices (DSPDs), programmable logic devices (PLDs), field programmable gate arrays (FPGAs), processors, controllers, microcontrollers, microprocessors, electronic units designed to perform their functions, or combinations thereof. For portions implemented in software, they may be implemented with the aid of microcode, program code, or code segments, and may also be stored in a machine-readable storage medium such as a storage component.

[0047] In one embodiment, the control unit 20 may be provided in an electronic control unit (ECU) of the vehicle, a vehicle body controller (VCU) of the vehicle, or a domain controller of the vehicle.

[0048] In one embodiment, the control unit 20 is implemented as including a memory and a processor. The memory contains instructions, which, when executed by the processor, enable the processor to perform the vehicle steering assist method according to an embodiment of the present invention.

[0049] The execution unit 30 is in communication with the control unit 20 and is configured to execute the vehicle steering assist strategy determined by the control unit 20. The execution unit 30 may, for example, include the vehicle's braking system for executing the braking maneuvers determined by the control unit 20. The execution unit 30 may also include the vehicle's drive system for executing the drive maneuvers determined by the control unit 20. The execution unit 30 may also include other control units signal-connected to the control unit 20. For example, when the control unit 20 is provided in an ECU (electronic control unit), the execution unit 30 may also include a VCU (vehicle control unit).

[0050] The following describes a vehicle steering assistance solution according to an embodiment of the present invention for each steering condition of the vehicle. The steering assistance solution for each vehicle steering condition includes solutions applicable to split-axle control vehicles and split-wheel control vehicles. Split-axle control vehicles include vehicles with 2 motors, that is, the front axle and rear axle of the vehicle are respectively coupled to a motor. Split-wheel control vehicles include 3-motor vehicles and 4-motor vehicles. 3-motor vehicles include vehicles with one motor coupled to the front axle and two motors coupled to the rear axle (that is, each wheel on the rear axle is coupled to a motor), and also include vehicles with two motors coupled to the front axle (that is, each wheel on the front axle is coupled to a motor) and one motor coupled to the rear axle. 4-motor vehicles include vehicles with one motor coupled to each of the four wheels.

[0051] Steering condition 1

[0052] 2 shows a vehicle steering assist method 200 according to an embodiment of the present invention. The method 200 can be executed by the control unit 20. The method 200 is applicable to a situation where a split-axle control vehicle is in a first steering condition.

[0053] 2 , at block 210 , the acquisition module 21 acquires vehicle yaw rate parameters and steering wheel angle parameters. The yaw rate parameters include the sensor yaw rate, the calculated yaw rate, the yaw rate ratio between the sensor yaw rate and the calculated yaw rate, the rate of increase of the sensor yaw rate, and the rate of decrease of the sensor yaw rate. The steering wheel angle parameters include the steering wheel angle, the rate of increase of the steering wheel angle, and the rate of decrease of the steering wheel angle.

[0054] At block 220 , the determination module 22 determines a change in the vehicle turning radius desired by the driver based on the acquired yaw rate parameter and the steering wheel angle parameter.

[0055] In one embodiment, the determination module 22 may determine whether the driver desires the vehicle's turning radius to increase or decrease based on the acquired yaw rate parameter and steering wheel angle parameter. For example, the determination module 22 performs the following comparisons: comparing the steering wheel angle with a steering wheel angle threshold; comparing the steering wheel angle increase rate with the steering wheel angle increase rate; comparing the steering wheel angle decrease rate with the steering wheel angle decrease rate; comparing the yaw rate ratio with a first yaw rate ratio threshold and a second yaw rate ratio threshold, respectively; comparing the yaw rate decrease rate with a yaw rate decrease rate threshold; and comparing the yaw rate increase rate with a yaw rate increase rate threshold. Furthermore, the determination module 22 determines whether the driver desires the vehicle turning radius to increase or decrease based on the comparison result, which includes: 1) when the steering wheel angle increase rate is greater than the steering wheel angle increase rate threshold, and the steering wheel angle is greater than the steering wheel angle threshold, determining that the driver desires to decrease the vehicle turning radius; 2) when the steering wheel angle decrease rate is greater than the steering wheel angle decrease rate threshold, and the steering wheel angle is less than the steering wheel angle threshold, determining that the driver desires to increase the vehicle turning radius; 3) when the yaw rate ratio is greater than 1 and less than the first yaw rate ratio threshold, and the steering wheel angle increase rate is greater than 4) when the yaw rate ratio is greater than 1 and the steering wheel angle decrease rate is greater than the steering wheel angle decrease rate threshold, it is determined that the driver desires to increase the vehicle turning radius; 5) when the yaw rate ratio is less than 1 and the steering wheel angle increase rate is greater than the steering wheel angle increase rate threshold, it is determined that the vehicle turning radius is reduced; 6) when the yaw rate ratio is less than 1 and greater than a second yaw rate ratio threshold, and the steering wheel angle decrease rate is greater than the steering wheel angle decrease rate threshold, it is determined that the vehicle turning radius is increased.

[0056] In this embodiment, the determination module 22 can also determine the degree of increase or decrease in the driver's desired turning radius based on the acquired yaw rate parameter and steering wheel angle parameter. Specifically, at the same vehicle speed, if the steering wheel angle is greater than a steering wheel angle threshold, the greater the rate of increase in the steering wheel angle, the greater the driver's desired decrease in the vehicle's turning radius, i.e., the smaller the turning radius. Furthermore, if the steering wheel angle is less than the steering wheel angle threshold, the greater the rate of decrease in the steering wheel angle, the greater the driver's desired increase in the vehicle's turning radius, i.e., the larger the turning radius. Examples of "same vehicle speed" include 1) situations where the vehicle speed values ​​are exactly the same; and 2) situations where the vehicle speed values ​​fall within the same vehicle speed range.

[0057] The degree of increase or decrease in the turning radius can be determined by looking up a table. For example, the following relationship table 1 can be prepared in advance, and the degree of increase or decrease in the turning radius can be found in Table 1 based on the current vehicle speed. In Table 1, the first column represents the vehicle speed, and speed 1-speed 3 represent three different levels of vehicle speed, and each level of vehicle speed includes a predetermined vehicle speed range. The second column represents the corresponding relationship between the steering wheel angle increase rate and the degree of decrease in the vehicle's turning radius when the steering wheel angle is greater than the steering wheel angle threshold. Different steering wheel angle increase rates correspond to different degrees of decrease in the vehicle's turning radius. The third column represents the corresponding relationship between the steering wheel angle decrease rate and the degree of increase in the vehicle's turning radius when the steering wheel angle is less than the steering wheel angle threshold. Different steering wheel angle decrease rates correspond to different degrees of increase in the vehicle's turning radius.

[0058] It should be understood that Table 1 lists only three speed levels; in specific applications, more or fewer speed levels may be implemented. Furthermore, according to embodiments of the present invention, for each speed level, multiple corresponding relationships between the rate of increase in steering wheel angle and the degree of decrease in turning radius may be provided, as well as multiple corresponding relationships between the rate of decrease in steering wheel angle and the degree of increase in turning radius. For example, for speed 1, when the steering wheel angle is greater than a steering wheel angle threshold, the following correspondences are provided: steering wheel angle increase rate 11 minus degree of decrease in turning radius 11'; steering wheel angle increase rate 12 minus degree of decrease in turning radius 12'; and steering wheel angle increase rate 13 minus degree of decrease in turning radius 13'. Furthermore, when the steering wheel angle is less than the steering wheel angle threshold, the following correspondences are provided: steering wheel angle decrease rate 11 minus degree of increase in turning radius 11'; steering wheel angle decrease rate 12 minus degree of increase in turning radius 12'; and steering wheel angle decrease rate 13 minus degree of increase in turning radius 13'.

[0059] Table 1

[0060] In box 230, the judgment module 23 determines whether the current state of the vehicle meets the preset steering condition one, that is, the judgment module 23 determines whether the current state of the vehicle meets the following conditions: the driving torque directions of the front axle inner wheel, the front axle outer wheel, the rear axle inner wheel and the rear axle outer wheel are all forward.

[0061] In block 240, when the determination module 22 determines that the driver desires to increase the turning radius and the judgment module 23 determines that the current state of the vehicle satisfies the steering condition 1, the decision module 24 decides to execute one or more of the following steering assist strategies: 1) when the front axle slip ratio does not reach the front axle target slip ratio (the front axle target slip ratio may be determined by the vehicle system based on the current road adhesion coefficient and vehicle attribute parameters), maintain or increase the front axle drive torque (when the steering wheel is stationary, maintain the front axle drive torque; and when the steering wheel is not stationary, increase the front axle drive torque); and when the front axle slip ratio reaches the front axle target slip ratio, maintain or increase the front axle target slip ratio. slip ratio (maintaining the front axle target slip ratio when the steering wheel is stationary; and increasing the front axle target slip ratio when the steering wheel is not stationary, thereby increasing the vehicle turning radius by generating understeer); 2) maintaining or increasing the rear axle drive torque when the rear axle slip ratio does not reach the rear axle target slip ratio (maintaining the rear axle drive torque when the steering wheel is stationary; and increasing the rear axle drive torque when the steering wheel is not stationary), and reducing the rear axle target slip ratio when the rear axle slip ratio reaches the rear axle target slip ratio (thereby reducing the oversteer tendency and thereby increasing the vehicle turning radius); and 3) providing a torque to at least one outer wheel in a direction opposite to the drive torque of the at least one outer wheel.

[0062] The "providing a torque opposite to the driving torque of the at least one outer wheel" in Strategy 3) above can be implemented using the aforementioned reverse torque control. For example, in a steering condition, the driving torque of the at least one outer wheel is directed forward, and thus the torque opposite to the driving torque of the at least one outer wheel is a reverse torque. Using the aforementioned reverse torque control, this reverse torque can be achieved by the vehicle's motor or by the vehicle's controller.

[0063] It should be understood that in the following embodiments, strategies for increasing the reverse torque on the axle or wheel can all be implemented by adopting such reverse torque control, which will not be elaborated on.

[0064] Moreover, when the determination module 22 determines that the driver desires to reduce the turning radius and the judgment module 23 determines that the current state of the vehicle satisfies the steering condition 1, the decision module 24 decides to execute one or more of the following steering assist strategies: 1) when the front axle slip ratio does not reach the front axle target slip ratio, maintain or reduce the front axle drive torque (when the steering wheel is stationary, maintain the front axle drive torque; and when the steering wheel is not stationary, reduce the front axle drive torque), and when the front axle slip ratio reaches the front axle target slip ratio, maintain or reduce the front axle target slip ratio (when the steering wheel is stationary, maintain the front axle target slip ratio; and when the steering wheel is not stationary, reduce the front axle target slip ratio. Here, the front axle The slip ratio reaches the front axle target slip ratio, which means that the front axle / front wheel of the vehicle has slipped and understeered, and the slip of the front axle / front wheel is reduced by lowering the target slip ratio, thereby reducing the tendency of understeer); 2) when the rear axle slip ratio does not reach the rear axle target slip ratio, the rear axle drive torque is reduced, and when the rear axle slip ratio reaches the rear axle target slip ratio, the rear axle target slip ratio is maintained or increased (when the steering wheel is stationary, the rear axle target slip ratio is maintained; and when the steering wheel is not stationary, the rear axle target slip ratio is increased, thereby increasing the degree of oversteer and allowing the rear axle of the vehicle to enter a controllable drift state); and 3) providing a torque to at least one inside wheel in a direction opposite to the drive torque of the at least one inside wheel.

[0065] In one embodiment, decision module 24 determines which steering assist strategies to implement based on the degree to which the driver's desired turning radius increases or decreases. For example, as the driver's desired turning radius increases or decreases, the following strategies are implemented, in order: slip ratio control strategy; reverse torque control strategy; and slip ratio control strategy and reverse torque control strategy. In other words, when the change in turning radius is small (e.g., the turning radius increases from 2 meters to 3 meters), a slip ratio control strategy is implemented, such as 1) and 2) of the aforementioned multiple steering assist strategies 1) to 3). When the change in turning radius is large (e.g., the turning radius increases from 2 meters to 4 meters), reverse torque control is implemented, such as 3) of the aforementioned multiple steering assist strategies 1) to 3). When the change in turning radius is large (e.g., the turning radius increases from 2 meters to 5 meters), both the slip ratio control strategy and reverse torque control strategy are implemented, such as all of the aforementioned multiple steering assist strategies 1) to 3).

[0066] This steering assist strategy is advantageous because reverse torque control can change the vehicle's turning radius more aggressively than slip ratio control, allowing the change to be completed more quickly. Therefore, when a significant change in the vehicle's turning radius is required, reverse torque control, or reverse torque control combined with slip ratio control, can achieve the desired change in radius much more quickly.

[0067] In one embodiment, decision module 24 determines which steering assist strategy to implement based on the vehicle's stability. For example, as vehicle stability decreases, the following strategies are implemented: slip ratio control strategy; reverse torque control strategy; and both slip ratio control and reverse torque control strategies. In other words, as vehicle stability decreases, steering control needs to be completed as quickly as possible. Therefore, combining reverse torque control with slip ratio control can achieve a shorter steering radius without requiring significant effort.

[0068] In this embodiment, the following method may be used to determine the stability of the vehicle.

[0069] When reducing the vehicle's turning radius, the vehicle's stability decreases in the following order:

[0070] a yaw rate ratio between a sensor yaw rate obtained based on the sensor measurement result and a calculated yaw rate calculated based on the driver's steering wheel operation is greater than 1 and less than a first yaw rate ratio threshold, and a sensor yaw rate reduction rate is greater than a yaw rate reduction rate threshold;

[0071] - the yaw rate ratio is greater than 1 and less than a first yaw rate ratio threshold, and the sensor yaw rate decrease rate is less than a yaw rate decrease rate threshold;

[0072] - the yaw rate ratio is greater than 1 and less than a first yaw rate ratio threshold, and the sensor yaw rate increase rate is less than a yaw rate increase rate threshold;

[0073] - the yaw rate ratio is greater than 1 and less than a first yaw rate ratio threshold, and the sensor yaw rate increase rate is greater than a yaw rate increase rate threshold;

[0074] - the yaw rate ratio is greater than 1 and greater than a first yaw rate ratio threshold, and the sensor yaw rate decrease rate is greater than a yaw rate decrease rate threshold;

[0075] - the yaw rate ratio is greater than 1 and greater than a first yaw rate ratio threshold, and the sensor yaw rate decrease rate is less than a yaw rate decrease rate threshold;

[0076] - the yaw rate ratio is greater than 1 and greater than a first yaw rate ratio threshold, and the sensor yaw rate increase rate is less than the yaw rate increase rate threshold;

[0077] The yaw rate ratio is greater than 1 and greater than a first yaw rate ratio threshold, and the sensor yaw rate increase rate is greater than a yaw rate increase rate threshold.

[0078] As the vehicle's turning radius increases, the vehicle's stability decreases in the following order:

[0079] a yaw rate ratio between a sensor yaw rate obtained based on the sensor measurement result and a calculated yaw rate calculated based on the driver's steering wheel operation is less than 1 and greater than a second yaw rate ratio threshold, and a sensor yaw rate increase rate is greater than the yaw rate increase rate threshold;

[0080] - the yaw rate ratio is less than 1 and greater than a second yaw rate ratio threshold, and the sensor yaw rate increase rate is less than a yaw rate increase rate threshold;

[0081] - the yaw rate ratio is less than 1 and greater than a second yaw rate ratio threshold, and the sensor yaw rate decrease rate is less than a yaw rate decrease rate threshold;

[0082] - the yaw rate ratio is less than 1 and greater than a second yaw rate ratio threshold, and the sensor yaw rate decrease rate is greater than a yaw rate decrease rate threshold;

[0083] - the yaw rate ratio is less than 1 and less than a second yaw rate ratio threshold, and the sensor yaw rate increase rate is greater than the yaw rate increase rate threshold;

[0084] - the yaw rate ratio is less than 1 and less than a second yaw rate ratio threshold, and the sensor yaw rate increase rate is less than a yaw rate increase rate threshold;

[0085] - the yaw rate ratio is less than 1 and less than a second yaw rate ratio threshold, and the sensor yaw rate decrease rate is less than a yaw rate decrease rate threshold;

[0086] The yaw rate ratio is less than 1 and less than a second yaw rate ratio threshold, and the sensor yaw rate decrease rate is greater than the yaw rate decrease rate threshold.

[0087] The first and second yaw rate ratio thresholds can be understood as the upper and lower limits of the permissible yaw rate ratio range. If the yaw rate ratio does not fall within this permissible range—that is, if the sensor yaw rate is significantly greater than the calculated yaw rate, or if the sensor yaw rate is significantly less than the calculated yaw rate—the vehicle is considered unstable. In this situation, the steering assist strategy according to this embodiment of the present invention is not applicable. If this occurs, other control strategies can be used to improve vehicle stability before implementing the steering assist strategy according to this embodiment of the present invention.

[0088] It is understood that an embodiment of the vehicle steering assist method has been described in detail above in conjunction with Figure 2. In the embodiments of the vehicle steering assist method described below, for features similar to those of method 200, the relevant descriptions of method 200 are applicable and will not be repeated.

[0089] 3 shows a vehicle steering assist method 300 according to an embodiment of the present invention. The method 300 may be executed by the control unit 20. The method 300 is applicable to a situation where a wheel-controlled vehicle is in a first steering condition.

[0090] 3 , at block 310 , the acquisition module 21 acquires a yaw rate parameter and a steering wheel angle parameter of the vehicle. The yaw rate parameter includes the yaw rate, the rate of increase of the yaw rate, and the rate of decrease of the yaw rate. The steering wheel angle parameter includes the steering wheel angle, the rate of increase of the steering wheel angle, and the rate of decrease of the steering wheel angle.

[0091] At block 320 , the determination module 22 determines a change in the driver's desired turning radius of the vehicle based on the acquired yaw rate parameter and steering wheel angle parameter. Regarding determining a change in the driver's desired turning radius of the vehicle, the above description in conjunction with block 220 also applies here and is not repeated here.

[0092] In box 330, the judgment module 23 determines whether the current state of the vehicle meets the preset steering condition one, that is, the judgment module 23 determines whether the current state of the vehicle meets the following conditions: the driving torques of the front axle inner wheel, the front axle outer wheel, the rear axle inner wheel and the rear axle outer wheel are all forward.

[0093] In box 340, when the determination module 22 determines that the driver desires to increase the turning radius and the judgment module 23 determines that the current state of the vehicle meets the steering condition one, the decision module 24 decides to execute one or more of the following steering assist strategies: 1) when the slip rates of the front axle inner wheel and the front axle outer wheel have not reached the front axle target slip rate, maintain or increase the front axle drive torque, and when the slip rate of at least one of the front axle inner wheel and the front axle outer wheel reaches the front axle target slip rate, maintain or increase the front axle target slip rate; 2) when the slip rates of the rear axle inner wheel and the rear axle outer wheel have not reached the rear axle target slip rate, maintain or increase the rear axle drive torque, and when the slip rate of at least one of the rear axle inner wheel and the rear axle outer wheel reaches the rear axle target slip rate, reduce the rear axle target slip rate; and 3) provide a torque to at least one outer wheel in a direction opposite to the drive torque of the at least one outer wheel.

[0094] Moreover, when the determination module 22 determines that the driver desires to reduce the turning radius and the judgment module 23 determines that the current state of the vehicle satisfies the steering condition 1, the decision module 24 decides to execute one or more of the following steering assist strategies: 1) when the slip rates of the front axle inner front wheel and the front axle outer wheel have not reached the front axle target slip rate, maintain or reduce the front axle drive torque, and when the slip rate of at least one of the front axle inner front wheel and the front axle outer wheel reaches the front axle target slip rate, maintain or reduce the front axle target slip rate; 2) when the slip rates of the rear axle inner wheel and the rear axle outer wheel have not reached the rear axle target slip rate, reduce the rear axle drive torque, and when the slip rate of at least one of the rear axle inner wheel and the rear axle outer wheel reaches the rear axle target slip rate, maintain or increase the rear axle target slip rate; and 3) provide a torque to at least one inner wheel that is opposite to the driving torque of the at least one inner wheel.

[0095] The above descriptions on deciding the steering assist strategy to be executed based on the degree of change of the turning radius and deciding the steering assist strategy to be executed based on the stability of the vehicle are also applicable here and are not repeated here.

[0096] Steering condition 2

[0097] 4 shows a vehicle steering assist method 400 according to an embodiment of the present invention. The method 400 may be executed by the control unit 20. The method 400 is applicable to a situation where a split-axle control vehicle is in a second steering condition.

[0098] 4 , at block 410 , the acquisition module 21 acquires a yaw rate parameter and a steering wheel angle parameter of the vehicle. The yaw rate parameter includes the yaw rate, the rate of increase of the yaw rate, and the rate of decrease of the yaw rate. The steering wheel angle parameter includes the steering wheel angle, the rate of increase of the steering wheel angle, and the rate of decrease of the steering wheel angle.

[0099] At block 420 , the determination module 22 determines a change in the driver's desired turning radius based on the acquired yaw rate parameter and steering wheel angle parameter. Regarding determining a change in the driver's desired turning radius, the description above in conjunction with block 220 also applies here and is not repeated here.

[0100] In box 430, the judgment module 23 determines whether the current state of the vehicle meets the preset steering condition 2, that is, the judgment module 23 determines whether the current state of the vehicle meets: the driving torque of the front axle inner wheel and the front axle outer wheel are both forward, and the driving torque of the rear axle inner wheel and the rear axle outer wheel are both backward.

[0101] In box 440, when the determination module 22 determines that the driver wants to increase the turning radius and the judgment module 23 determines that the current state of the vehicle meets the steering condition two, the decision module 24 decides to execute one or more of the following steering assist strategies: 1) when the front axle slip rate does not reach the front axle target slip rate, maintain or increase the front axle drive torque, and when the front axle slip rate reaches the front axle target slip rate, maintain or reduce the front axle target slip rate; 2) when the rear axle slip rate does not reach the rear axle target slip rate, maintain or reduce the rear axle drive torque, and when the rear axle slip rate reaches the rear axle target slip rate, reduce the rear axle target slip rate; 3) provide a torque opposite to the driving torque of the front axle outer wheel to the front and rear outer wheels; 4) provide a torque opposite to the driving torque of the rear axle inner wheel to the rear axle inner wheel.

[0102] Moreover, when the determination module 22 determines that the driver desires to reduce the turning radius and the judgment module 23 determines that the current state of the vehicle satisfies the steering condition 2, the decision module 24 decides on the following multiple steering assist strategies and selects to execute one of the steering assist strategies based on the degree of stability of the vehicle: 1) when the front axle slip rate does not reach the front axle target slip rate, maintain or reduce the front axle drive torque, and when the front axle slip rate reaches the front axle target slip rate, maintain or increase the front axle target slip rate; 2) when the rear axle slip rate does not reach the rear axle target slip rate, increase the rear axle drive torque, and when the rear axle slip rate reaches the rear axle target slip rate, maintain or increase the rear axle target slip rate; 3) provide a torque to the inner wheel of the front axle that is opposite in direction to the drive torque of the inner wheel of the front axle; 4) provide a torque to the outer wheel of the rear axle that is opposite in direction to the drive torque of the outer wheel of the rear axle.

[0103] The above descriptions on deciding the steering assist strategy to be executed based on the degree of change of the turning radius and deciding the steering assist strategy to be executed based on the stability of the vehicle are also applicable here and are not repeated here.

[0104] 5 shows a vehicle steering assist method 500 according to an embodiment of the present invention. The method 500 may be executed by the control unit 20. The method 500 is applicable to a situation where a wheel-split control vehicle is in a second steering condition.

[0105] At block 510, the acquisition module 21 acquires a yaw rate parameter and a steering wheel angle parameter of the vehicle. The yaw rate parameter includes the yaw rate, the rate of increase of the yaw rate, and the rate of decrease of the yaw rate. The steering wheel angle parameter includes the steering wheel angle, the rate of increase of the steering wheel angle, and the rate of decrease of the steering wheel angle.

[0106] At block 520 , the determination module 22 determines a change in the driver's desired turning radius of the vehicle based on the acquired yaw rate parameter and steering wheel angle parameter. Regarding determining a change in the driver's desired turning radius of the vehicle, the above description in conjunction with block 220 also applies here and is not repeated here.

[0107] In box 530, the judgment module 23 determines whether the current state of the vehicle meets the preset steering condition 2, that is, the judgment module 23 determines whether the current state of the vehicle meets: the driving torque of the front axle inner wheel and the front axle outer wheel are both forward, and the driving torque of the rear axle inner wheel and the rear axle outer wheel are both backward.

[0108] In block 540, if the determination module 22 determines that the driver desires to increase the turning radius and the judgment module 23 determines that the current state of the vehicle satisfies the second steering condition, the decision module 24 decides to execute one or more of the following steering assist strategies: 1) when the slip ratios of the front axle inner wheel and the front axle outer wheel do not reach the front wheel target slip ratio, maintain or increase the front axle drive torque, and when the slip ratio of at least one of the front axle inner wheel and the front axle outer wheel reaches the front axle target slip ratio, maintain or reduce the front axle target slip ratio; 2) when the slip ratios of the rear axle inner wheel and the rear axle outer wheel do not reach the rear axle target slip ratio, maintain or reduce the rear axle drive torque, and when the slip ratio of at least one of the rear axle inner wheel and the rear axle outer wheel reaches the rear axle target slip ratio, reduce the rear axle target slip ratio; 3) provide a torque to the front axle outer wheel in a direction opposite to the drive torque of the front axle outer wheel; and 4) provide a torque to the rear axle inner wheel in a direction opposite to the drive torque provided to the rear axle inner wheel.

[0109] Moreover, when the determination module 22 determines that the driver desires to reduce the turning radius and the judgment module 23 determines that the current state of the vehicle satisfies the steering condition 2, the decision module 24 decides to execute one or more of the following steering assist strategies: 1) when the slip rates of the front axle inner wheel and the front axle outer wheel have not reached the front axle target slip rate, maintain or reduce the front axle drive torque, and when the slip rate of at least one of the front axle inner wheel and the front axle outer wheel reaches the front axle target slip rate, maintain or increase the front axle target slip rate; 2) when the slip rates of the rear axle outer wheel and the rear axle inner wheel have not reached the rear axle target slip rate, increase the rear axle drive torque, and when the slip rate of at least one of the rear axle inner wheel and the rear axle outer wheel reaches the rear axle target slip rate, maintain or increase the rear axle target slip rate; 3) provide the front axle inner wheel with a torque in a direction opposite to the drive torque of the front axle inner wheel; 4) provide the rear axle outer wheel with a torque in a direction opposite to the drive torque of the rear axle outer wheel.

[0110] Steering condition three

[0111] 6 shows a vehicle steering assist method 600 according to an embodiment of the present invention. The method 600 may be executed by the control unit 20. The method 600 is applicable to a situation where a split-axle control vehicle is in a steering condition three.

[0112] 6 , at block 610 , the acquisition module 21 acquires a yaw rate parameter and a steering wheel angle parameter of the vehicle. The yaw rate parameter includes the yaw rate, the rate of increase of the yaw rate, and the rate of decrease of the yaw rate. The steering wheel angle parameter includes the steering wheel angle, the rate of increase of the steering wheel angle, and the rate of decrease of the steering wheel angle.

[0113] At block 620 , the determination module 22 determines a change in the driver's desired turning radius of the vehicle based on the acquired yaw rate parameter and steering wheel angle parameter. Regarding determining a change in the driver's desired turning radius of the vehicle, the description above in conjunction with block 220 also applies here and is not repeated here.

[0114] In box 630, the judgment module 23 determines whether the current state of the vehicle meets the preset steering condition three, that is, the judgment module 23 determines whether the current state of the vehicle meets: the driving torque of the front axle inner wheel and the front axle outer wheel are both backward, and the driving torque of the rear axle inner wheel and the rear axle outer wheel are both forward.

[0115] In box 640, when the determination module 22 determines that the driver wants to increase the turning radius and the judgment module 23 determines that the current state of the vehicle meets the steering condition three, the decision module 24 decides to execute one or more of the following steering assist strategies: 1) when the front axle slip rate does not reach the front axle target slip rate, maintain or reduce the front axle driving torque, and when the front axle slip rate reaches the front axle target slip rate, increase the front axle target slip rate; 2) when the rear axle slip rate does not reach the rear axle target slip rate, maintain or increase the rear axle driving torque, and when the rear axle slip rate reaches the rear axle target slip rate, reduce the rear axle target slip rate; 3) provide a driving torque opposite to the driving torque of the inner wheel of the front axle to the inner wheel of the front axle; 4) provide a torque opposite to the driving torque of the outer wheel of the rear axle to the outer wheel of the rear axle.

[0116] Moreover, when the determination module 22 determines that the driver wants to reduce the turning radius and the judgment module 23 determines that the current state of the vehicle satisfies the steering condition three, the decision module 24 decides to execute one or more of the following steering assist strategies: 1) when the front axle slip rate does not reach the front axle target slip rate, maintain or increase the front axle driving torque, and when the front axle slip rate reaches the front axle target slip rate, reduce the front axle target slip rate; 2) when the rear axle slip rate does not reach the rear axle target slip rate, maintain or reduce the rear axle driving torque, and when the rear axle slip rate reaches the rear axle target slip rate, increase the rear axle target slip rate; 3) provide a driving torque to the outer wheel of the front axle in a direction opposite to the driving torque of the outer wheel of the front axle; 4) provide a torque to the inner wheel of the rear axle in a direction opposite to the driving torque of the inner wheel of the rear axle.

[0117] 7 shows a vehicle steering assist method 700 according to an embodiment of the present invention. The method 700 may be executed by the control unit 20. The method 700 is applicable to a situation where a wheel-split control vehicle is in a steering condition three.

[0118] 7 , at block 710 , the acquisition module 21 acquires a yaw rate parameter and a steering wheel angle parameter of the vehicle. The yaw rate parameter includes the yaw rate, the rate of increase of the yaw rate, and the rate of decrease of the yaw rate. The steering wheel angle parameter includes the steering wheel angle, the rate of increase of the steering wheel angle, and the rate of decrease of the steering wheel angle.

[0119] At block 720 , the determination module 22 determines a change in the driver's desired turning radius of the vehicle based on the acquired yaw rate parameter and steering wheel angle parameter. Regarding determining a change in the driver's desired turning radius of the vehicle, the above description in conjunction with block 220 also applies here and is not repeated here.

[0120] In box 730, the judgment module 23 determines whether the current state of the vehicle meets the preset steering condition three, that is, the judgment module 23 determines whether the current state of the vehicle meets: the driving torque of the front axle inner wheel and the front axle outer wheel are both backward, and the driving torque of the rear axle inner wheel and the rear axle outer wheel are both forward.

[0121] In block 740, if the determination module 22 determines that the driver desires to increase the turning radius and the judgment module 23 determines that the current state of the vehicle satisfies the steering operating condition three, the decision module 24 decides to execute one or more of the following steering assist strategies: 1) when the slip ratios of the front axle inner wheel and the front axle outer wheel do not reach the front axle target slip ratio, maintain or reduce the front axle drive torque, and when the slip ratio of at least one of the front axle inner wheel and the front axle outer wheel reaches the front axle target slip ratio, increase the front axle target slip ratio; 2) when the slip ratios of the rear axle inner wheel and the rear axle outer wheel do not reach the rear axle target slip ratio, maintain or increase the rear axle drive torque, and when the slip ratio of at least one of the rear axle inner wheel and the rear axle outer wheel reaches the rear axle target slip ratio, reduce the rear axle target slip ratio; 3) provide a drive torque in a direction opposite to the drive torque of the front axle inner wheel to the front axle inner wheel; and 4) provide a torque in a direction opposite to the drive torque of the rear axle outer wheel to the rear axle outer wheel.

[0122] Moreover, when the determination module 22 determines that the driver desires to reduce the turning radius and the judgment module 23 determines that the current state of the vehicle satisfies the steering condition three, the decision module 24 decides to execute one or more of the following steering assist strategies: 1) when the slip ratios of the front axle inner wheel and the front axle outer wheel have not reached the front wheel target slip ratio, maintain or increase the front axle drive torque, and when the slip ratio of at least one of the front axle inner wheel and the front axle outer wheel reaches the front axle target slip ratio, reduce the front axle target slip ratio; 2) when the slip ratios of the rear axle inner wheel and the rear axle outer wheel have not reached the rear axle target slip ratio, maintain or reduce the rear axle drive torque, and when the slip ratio of at least one of the rear axle inner wheel and the rear axle outer wheel reaches the rear axle target slip ratio, increase the rear axle target slip ratio; 3) provide a driving torque in a direction opposite to the driving torque of the front axle outer wheel to the front axle outer wheel; 4) provide a torque in a direction opposite to the driving torque of the rear axle inner wheel to the rear axle inner wheel.

[0123] The above descriptions on deciding the steering assist strategy to be executed based on the degree of change of the turning radius and deciding the steering assist strategy to be executed based on the stability of the vehicle are also applicable here and are not repeated here.

[0124] Steering condition four

[0125] FIG8 shows a vehicle steering assist method 800 according to an embodiment of the present invention. The method 800 may be executed by the control unit 20. The method 800 is applicable to a vehicle using split-axle control in a steering condition 4.

[0126] 8 , at block 810 , the acquisition module 21 acquires a yaw rate parameter and a steering wheel angle parameter of the vehicle. The yaw rate parameter includes the yaw rate, the rate of increase of the yaw rate, and the rate of decrease of the yaw rate. The steering wheel angle parameter includes the steering wheel angle, the rate of increase of the steering wheel angle, and the rate of decrease of the steering wheel angle.

[0127] At block 820 , the determination module 22 determines a change in the driver's desired turning radius of the vehicle based on the acquired yaw rate parameter and steering wheel angle parameter. Regarding determining a change in the driver's desired turning radius of the vehicle, the description above in conjunction with block 220 also applies here and is not repeated here.

[0128] In box 830, the judgment module 23 determines whether the current state of the vehicle meets the preset steering condition four, that is, the judgment module 23 determines whether the current state of the vehicle meets: the driving torque of the front axle inner wheel, the front axle outer wheel, the rear axle inner wheel and the rear axle outer wheel are all backward.

[0129] In box 840, when the determination module 22 determines that the driver wants to increase the turning radius and the judgment module 23 determines that the current state of the vehicle meets the steering condition four, the decision module 24 decides to execute one or more of the following steering assist strategies: 1) when the front axle slip rate does not reach the front axle target slip rate, maintain or reduce the front axle driving torque, and when the front axle slip rate reaches the front axle target slip rate, increase the front axle target slip rate; 2) when the rear axle slip rate does not reach the rear axle target slip rate, maintain or reduce the rear axle driving torque, and when the rear axle slip rate reaches the rear axle target slip rate, reduce the front axle target slip rate; 3) provide a driving torque to at least one inner wheel that is opposite to the driving torque direction of the at least one inner wheel.

[0130] Moreover, when the determination module 22 determines that the driver desires to reduce the turning radius and the judgment module 23 determines that the current state of the vehicle satisfies steering condition four, the decision module 24 decides to execute one or more of the following steering assist strategies: 1) when the front axle slip rate does not reach the front axle target slip rate, maintain or increase the front axle drive torque, and when the front axle slip rate reaches the front axle target slip rate, reduce the front axle target slip rate; 2) when the rear axle slip rate does not reach the rear axle target slip rate, maintain or increase the front axle drive torque, and when the rear axle slip rate reaches the rear axle target slip rate, increase the rear axle target slip rate; 3) provide a torque to at least one outer wheel that is opposite to the driving torque of the at least one outer wheel.

[0131] FIG9 shows a vehicle steering assist method 900 according to an embodiment of the present invention. The method 900 may be executed by the control unit 20. The method 900 is applicable to a situation where a vehicle using a split-wheel control system is in a steering condition 4.

[0132] 9 , at block 910 , the acquisition module 21 acquires a yaw rate parameter and a steering wheel angle parameter of the vehicle. The yaw rate parameter includes the yaw rate, the rate of increase of the yaw rate, and the rate of decrease of the yaw rate. The steering wheel angle parameter includes the steering wheel angle, the rate of increase of the steering wheel angle, and the rate of decrease of the steering wheel angle.

[0133] At block 920 , the determination module 22 determines a change in the driver's desired turning radius of the vehicle based on the acquired yaw rate parameter and steering wheel angle parameter. Regarding determining a change in the driver's desired turning radius of the vehicle, the description above in conjunction with block 220 also applies here and is not repeated here.

[0134] In box 930, the judgment module 23 determines whether the current state of the vehicle meets the preset steering condition four, that is, the judgment module 23 determines whether the current state of the vehicle meets: the driving torque of the front axle inner wheel, the front axle outer wheel, the rear axle inner wheel and the rear axle outer wheel are all backward.

[0135] In box 940, when the determination module 22 determines that the driver wants to increase the turning radius and the judgment module 23 determines that the current state of the vehicle meets the steering condition four, the decision module 24 decides one or more of the following steering assist strategies: 1) when the slip ratios of the front axle inner wheel and the front axle outer wheel have not reached the front axle target slip ratio, maintain or reduce the front axle driving torque, and when the slip ratio of at least one of the front axle inner wheel and the front axle outer wheel reaches the front axle target slip ratio, increase the front axle target slip ratio; 2) when the slip ratios of the rear axle inner wheel and the rear axle outer wheel have not reached the rear axle target slip ratio, maintain or reduce the rear axle driving torque, and when the slip ratio of at least one of the rear axle inner wheel and the rear axle outer wheel reaches the rear axle target slip ratio, reduce the front axle target slip ratio; 3) provide a torque to at least one inner wheel in a direction opposite to the driving torque of the at least one inner wheel.

[0136] Moreover, when the determination module 22 determines that the driver wants to reduce the turning radius and the judgment module 23 determines that the current state of the vehicle meets the steering condition four, the decision module 24 decides to execute one or more of the following steering assist strategies: 1) when the slip rate of the front axle inner road and the front axle outer wheel does not reach the front axle target slip rate, maintain or increase the front axle drive torque, and when the slip rate of at least one of the front axle inner wheel and the front axle outer wheel reaches the front axle target slip rate, reduce the front axle target slip rate; 2) when the slip rate of the rear axle inner wheel and the rear axle outer wheel does not reach the rear axle target slip rate, maintain or increase the front axle drive torque, and when the slip rate of at least one of the rear axle inner wheel and the rear axle outer wheel reaches the rear axle target slip rate, increase the rear axle target slip rate; 3) provide a torque to at least one outer wheel in the opposite direction to the driving torque of the at least one outer wheel.

[0137] The present invention further provides a machine-readable storage medium storing executable instructions, which, when executed, enable one or more processors to perform one or more of the vehicle steering assistance methods 200 - 900 described above.

[0138] It should be noted that all operations in the method described above are merely exemplary, and the present disclosure is not limited to any operation in the method or the order of these operations, but should cover all other equivalent transformations under the same or similar concept.

[0139] It should be noted that the processor may be any combination of one or more of the following: a suitable central processing unit, CPU, multiprocessor, single-chip microcomputer, digital signal processor, DSP, application-specific integrated circuit, etc., capable of executing software instructions of a computer program stored in the memory. Therefore, the memory may be considered to be part of or form part of the computer program product. The processor may be configured to execute the computer program stored therein to cause the controller to perform the required steps.

[0140] It should be noted that software should be broadly considered to mean instructions, instruction sets, codes, code segments, program codes, programs, subroutines, software modules, applications, software applications, software packages, routines, subroutines, objects, running threads, processes, functions, etc. Software can reside in a computer-readable medium. A computer-readable medium can include, for example, a memory, which can be, for example, a magnetic storage device (e.g., a hard disk, a floppy disk, a magnetic stripe), an optical disk, a smart card, a flash memory device, a random access memory (RAM), a read-only memory (ROM), a programmable ROM (PROM), an erasable PROM (EPROM), an electrically erasable PROM (EEPROM), a register, or a removable disk. Although the memory is shown as being separate from the processor in various aspects provided in the present disclosure, the memory can also be located inside the processor (e.g., a cache or register).

[0141] The above description is provided to enable any person skilled in the art to implement the various aspects described herein. Various modifications to these aspects will be apparent to those skilled in the art, and the general principles defined herein may be applied to other aspects. Therefore, the claims are not intended to be limited to the aspects shown herein. All structural and functional equivalents of the elements of the various aspects described in this disclosure that are known or to be known to those skilled in the art are expressly incorporated herein by reference and are intended to be covered by the claims.

Claims

1. A control unit for a vehicle steering assist system, comprising: An acquisition module configured to acquire a yaw rate parameter and a steering wheel angle parameter of the vehicle; a determination module configured to determine whether the vehicle driver desires to increase or decrease the vehicle turning radius based on the acquired yaw rate parameter and the steering wheel angle parameter; a determination module configured to determine whether the current state of the vehicle satisfies: the driving torque directions of the front axle inner wheel and the front axle outer wheel are both forward, and the driving torque directions of the rear axle inner wheel and the rear axle outer wheel are both backward; and The decision module is configured as follows: When the determination module determines that the driver wants to increase the turning radius of the vehicle and the determination result of the judgment module is affirmative, the decision is to execute one or more of the following steering assist strategies: 1) when the front axle slip rate does not reach the front axle target slip rate, maintain or increase the front axle drive torque, and when the front axle slip rate reaches the front axle target slip rate, maintain or reduce the front axle target slip rate; 2) when the rear axle slip rate does not reach the rear axle target slip rate, maintain or reduce the rear axle drive torque, and when the rear axle slip rate reaches the rear axle target slip rate, reduce the rear axle target slip rate; 3) provide a torque opposite to the driving torque of the front axle outer wheel to the front and rear outer wheels; 4) provide a torque opposite to the driving torque of the rear axle inner wheel to the rear axle inner wheel; and When the determination module determines that the driver wants to reduce the vehicle turning radius and the judgment result of the judgment module is affirmative, the decision is to execute one or more of the following steering assist strategies: 1) when the front axle slip rate does not reach the front axle target slip rate, maintain or reduce the front axle drive torque, and when the front axle slip rate reaches the front axle target slip rate, maintain or increase the front axle target slip rate; 2) when the rear axle slip rate does not reach the rear axle target slip rate, increase the rear axle drive torque, and when the rear axle slip rate reaches the rear axle target slip rate, maintain or increase the rear axle target slip rate; 3) provide a torque in the opposite direction of the driving torque of the inner wheel of the front axle to the inner wheel of the front axle; 4) provide a torque in the opposite direction of the driving torque of the outer wheel of the rear axle to the outer wheel of the rear axle.

2. A control unit for a vehicle steering assist system, comprising: An acquisition module configured to acquire a yaw rate parameter and a steering wheel angle parameter of the vehicle; a determination module configured to determine whether the vehicle driver desires to increase or decrease the vehicle turning radius based on the acquired yaw rate parameter and the steering wheel angle parameter; The judging module is configured to judge whether the current state of the vehicle satisfies: the inner wheel of the front axle and the outer wheel of the front axle The driving torque direction is forward, and the driving torque direction of the inner wheel of the rear axle and the outer wheel of the rear axle is backward; and A decision module is configured to: when the determination module determines that the driver wants to increase the turning radius of the vehicle and the determination result of the judgment module is affirmative, decide to execute one or more of the following steering assist strategies: 1) when the slip rates of the inner wheel of the front axle and the outer wheel of the front axle have not reached the front wheel target slip rate, maintain or increase the front axle drive torque, and when the slip rate of at least one of the inner wheel of the front axle and the outer wheel of the front axle reaches the front axle target slip rate, maintain or reduce the front axle target slip rate; 2) when the slip rates of the inner wheel of the rear axle and the outer wheel of the rear axle have not reached the rear axle target slip rate, maintain or reduce the rear axle drive torque, and when the slip rate of at least one of the inner wheel of the rear axle and the outer wheel of the rear axle reaches the rear axle target slip rate, reduce the rear axle target slip rate; 3) provide a torque opposite to the driving torque of the outer wheel of the front axle to the outer wheel of the front axle; 4) provide a torque opposite to the driving torque provided to the inner wheel of the rear axle to the inner wheel of the rear axle; and When the determination module determines that the driver wants to reduce the turning radius of the vehicle and the determination result of the judgment module is affirmative, the decision is to execute one or more of the following steering assist strategies: 1) when the slip rates of the inner wheel of the front axle and the outer wheel of the front axle have not reached the front axle target slip rate, maintain or reduce the front axle drive torque, and when the slip rate of at least one of the inner wheel of the front axle and the outer wheel of the front axle reaches the front axle target slip rate, maintain or increase the front axle target slip rate; 2) when the slip rates of the outer wheel of the rear axle and the inner wheel of the rear axle have not reached the rear axle target slip rate, increase the rear axle drive torque, and when the slip rate of at least one of the inner wheel of the rear axle and the outer wheel of the rear axle reaches the rear axle target slip rate, maintain or increase the rear axle target slip rate; 3) provide the inner wheel of the front axle with a torque in the opposite direction of the drive torque of the inner wheel of the front axle; 4) provide the outer wheel of the rear axle with a torque in the opposite direction of the drive torque of the outer wheel of the rear axle.

3. A control unit according to claim 1 or 2, wherein: The yaw rate parameters include: a yaw rate ratio between a sensor yaw rate obtained based on a sensor measurement result and a calculated yaw rate obtained based on calculation of a driver's operation of a steering wheel, an increase rate of the sensor yaw rate, and a decrease rate of the sensor yaw rate; and The steering wheel angle parameters include: steering wheel angle, steering wheel angle increase rate and steering wheel angle decrease rate.

4. The control unit according to claim 3, wherein: Determining whether the vehicle driver intends to increase or decrease the vehicle turning radius based on the acquired yaw rate parameter and the steering wheel angle parameter includes: -When the steering wheel angle increase rate is greater than the steering wheel angle increase rate threshold, and the steering wheel angle is greater than the direction When the wheel angle threshold is reached, it is determined that the driver desires to reduce the vehicle turning radius; - when the steering wheel angle reduction rate is greater than the steering wheel angle reduction rate threshold and the steering wheel angle is less than the steering wheel angle threshold, determining that the driver desires to increase the vehicle turning radius; - when the yaw rate ratio is greater than 1 and less than a first yaw rate ratio threshold, and the steering wheel increase rate is greater than the steering wheel angle increase rate threshold, determining to reduce the vehicle turning radius; - when the yaw rate ratio is greater than 1 and the steering wheel angle reduction rate is greater than a steering wheel angle reduction rate threshold, determining that the driver desires to increase the vehicle turning radius; - when the yaw rate ratio is less than 1 and the steering wheel angle increase rate is greater than a steering wheel angle increase rate threshold, determining to reduce the vehicle turning radius; When the yaw rate ratio is less than 1 and greater than a second yaw rate ratio threshold, and a steering wheel angle reduction rate is greater than a steering wheel angle reduction rate threshold, it is determined to increase the vehicle turning radius.

5. The control unit according to claim 1 or 2, wherein: The determination module is further configured to determine a degree of increase or decrease in a turning radius of the vehicle desired by the vehicle driver based on the acquired yaw rate parameter and the steering wheel angle parameter.

6. The control unit according to claim 5, wherein: Determining the degree of increase or decrease of the turning radius of the vehicle desired by the vehicle driver based on the acquired yaw rate parameter and the steering wheel angle parameter includes: for the same vehicle speed: When the steering wheel angle is greater than the steering wheel angle threshold, if the steering wheel angle increase rate is greater, the driver expects the vehicle turning radius to be reduced more; as well as When the steering wheel angle is less than the steering wheel angle threshold, if the steering wheel angle decrease rate is greater, the driver expects the vehicle turning radius to increase more.

7. The control unit according to claim 5, wherein: The decision to execute one or more of the plurality of steering assist strategies includes: sequentially selecting to execute as the driver's desired turning radius increases or decreases more: - Slip control strategy; - reverse torque control strategy; and -Slip ratio control strategy and reverse torque control strategy.

8. The control unit according to claim 1 or 2, wherein: The decision to implement one or more of the plurality of steering assist strategies includes selecting, in order as the degree of vehicle stability decreases: - Slip control strategy; - reverse torque control strategy; and -Slip ratio control strategy and reverse torque control strategy.

9. The control unit according to claim 1 or 2, wherein: When reducing the turning radius of the vehicle, the degree of vehicle stability decreases in the following order: - a yaw rate ratio between a sensor yaw rate obtained based on the sensor measurement result and a calculated yaw rate obtained based on calculation of the driver's operation of the steering wheel is greater than 1 and less than a first yaw rate ratio threshold, and a rate of decrease of the sensor yaw rate is greater than a yaw rate decrease rate threshold; - the yaw rate ratio is greater than 1 and less than a first yaw rate ratio threshold, and a rate of decrease of the sensor yaw rate is less than a yaw rate decrease rate threshold; - the yaw rate ratio is greater than 1 and less than a first yaw rate ratio threshold, and the rate of increase of the sensor yaw rate is less than a yaw rate increase rate threshold; - the yaw rate ratio is greater than 1 and less than a first yaw rate ratio threshold, and the rate of increase of the sensor yaw rate is greater than a yaw rate increase rate threshold; - the yaw rate ratio is greater than 1 and greater than a first yaw rate ratio threshold, and a rate of decrease of the sensor yaw rate is greater than a yaw rate decrease rate threshold; - the yaw rate ratio is greater than 1 and greater than a first yaw rate ratio threshold, and a rate of decrease of the sensor yaw rate is less than a yaw rate decrease rate threshold; - the yaw rate ratio is greater than 1 and greater than a first yaw rate ratio threshold, and the rate of increase of the sensor yaw rate is less than a yaw rate increase rate threshold; The yaw rate ratio is greater than 1 and greater than a first yaw rate ratio threshold, and a rate of increase of the sensor yaw rate is greater than a yaw rate increase rate threshold.

10. The control unit according to claim 1 or 2, wherein: With increasing vehicle turning radius, the vehicle's stability level decreases in the following order: - a yaw rate ratio between a sensor yaw rate obtained based on the sensor measurement result and a calculated yaw rate obtained based on calculation of the driver's operation of the steering wheel is less than 1 and greater than a second yaw rate ratio threshold, and an increase rate of the sensor yaw rate is greater than a yaw rate increase rate threshold; - the yaw rate ratio is less than 1 and greater than a second yaw rate ratio threshold, and the rate of increase of the sensor yaw rate is less than a yaw rate increase rate threshold; - the yaw rate ratio is less than 1 and greater than a second yaw rate ratio threshold, and a rate of decrease of the sensor yaw rate is less than a yaw rate decrease rate threshold; - the yaw rate ratio is less than 1 and greater than a second yaw rate ratio threshold, and a rate of decrease of the sensor yaw rate is greater than a yaw rate decrease rate threshold; - the yaw rate ratio is less than 1 and less than a second yaw rate ratio threshold, and the rate of increase of the sensor yaw rate is greater than the yaw rate increase rate threshold; - the yaw rate ratio is less than 1 and less than a second yaw rate ratio threshold, and the rate of increase of the sensor yaw rate is less than a yaw rate increase rate threshold; - the yaw rate ratio is less than 1 and less than a second yaw rate ratio threshold, and the rate of decrease of the sensor yaw rate is less than a yaw rate decrease rate threshold; The yaw rate ratio is less than 1 and less than a second yaw rate ratio threshold, and a rate of decrease of the sensor yaw rate is greater than a yaw rate decrease rate threshold.

11. A vehicle steering assist system, comprising: a sensor unit configured to sense and / or receive a yaw rate parameter and a steering wheel angle parameter of the vehicle; The control unit according to any one of claims 1 to 10, configured to decide a steering assist strategy based on a yaw rate parameter and a steering wheel angle parameter of the vehicle and corresponding thresholds; as well as The actuator unit is configured to execute a steering assist strategy of the decision through one or more of slip ratio control, brake control and drive control.

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