Vehicle steering control device

Patent metadata

Field	Value
Publication number	US-12479504-B2
Application number	US-202218054665-A
Country	US
Kind code	B2
Filing date	Nov 11, 2022
Priority date	Jun 19, 2020
Publication date	Nov 25, 2025
Grant date	Nov 25, 2025

Abstract

A steering control device is configured to control a steering of a vehicle having at least one piloted actuator associated with a system for steering a wheel of the vehicle and a piloted actuator associated with a decoupled braking system at a wheel of the vehicle. The steering control device includes at least one control unit. The control unit is configured to recover at least one value characteristic of the travel of the vehicle and to issue a control instruction to the at least one piloted actuator according to the recovered value(s). The control unit includes a calculation module in which a model of a lateral dynamic behavior of the vehicle frame is implemented. At least one specific physical quantity of the lateral dynamic behavior is expressed according to the specific drifts of each set of front wheels and rear wheels of the vehicle.

First claim

What is claimed is:

1 . A steering control device for controlling at least one control actuator associated with one of a steering system of a vehicle and of a decoupled braking system at a wheel of the vehicle, the control device comprising:
at least one control unit having a processor configured to retrieve at least one characteristic value of driving of the vehicle and to transmit a control command as a function of the least one characteristic value to the at least one control actuator, and the control unit being configured to implement a lateral dynamic behavior model of a chassis of the vehicle in which at least one specific physical quantity of a lateral dynamic behavior of the vehicle is expressed as a function of specific drifts of each of the front and rear wheel axles of the vehicle.

2 . The steering control device according to claim 1 , wherein
the lateral dynamic behavior model implemented by the control unit is configured such that at least a yaw rate is expressed as a function of the specific drifts of each of the front and rear wheel axles of the vehicle.

3 . The steering control device according to claim 2 , wherein
the lateral dynamic behavior model implemented by the control unit is configured to express a transfer function between the yaw rate and the steering system of at least one of the front wheel axle and the rear wheel axle, as well as a transfer function between a yaw moment exerted by the at least one actuator associated with the decoupled braking system as a function of a static-dynamic gain defined as the function of the specific drifts of the front and rear wheel axles of the vehicle.

4 . The steering control device according to claim 3 , wherein
the control unit is configured to output a priority control command directed to the at least one control actuator associated with the steering system, before transmitting a control command directed to the at least one control actuator associated with the steering system.

5 . The steering control device according to claim 3 , wherein
the static-dynamic gain relating to each of the steering systems of the front and rear wheel axles is a function of an understeer gradient, that is a difference between the specific drift of the front wheel axle and the specific drift of the rear wheel axle.

6 . The steering control device according to claim 5 , wherein
the control unit is configured to output a priority control command directed to the at least one control actuator associated with the steering system of the rear wheel set before transmitting a control command directed to the at least one control actuator associated with the steering system of the wheel axle.

7 . The steering control device according to claim 1 , wherein
the control unit is configured to receive input parameters and dynamic driving parameters, and the control unit is further configured to first compare a reference datum calculated by applying the lateral dynamic behavior model from values of the input parameters and reference values of the dynamic driving parameters, to an actual datum calculated by applying the lateral dynamic behavior model from values of the same input parameters and actual values of the dynamic driving parameters, and subsequently in a second time generating corrective action instructions in an event of a significant deviation between the reference datum and the actual datum.

8 . The steering control device according to claim 7 , wherein
the reference datum is a reference yaw moment and the actual datum is an effective yaw moment, the control unit is configured to calculate the reference yaw moment using the lateral dynamic behavior model with the reference values and to calculate the yaw moment effective (using the lateral dynamic behavior model with the actual values.

9 . The steering control device according to claim 8 , wherein
the control unit is configured to calculate simultaneously the reference yaw moment and the effective yaw moment.

10 . The steering control device according to claim 8 , wherein
the at least one control actuator is an actuator of the steering angle of a rear wheel of the vehicle, the steering angle of the rear wheel being determined for a front wheel set angle of the determined chassis and for equality of the calculated reference yaw moment with the calculated effective yaw moment.

11 . The steering control device according to claim 8 , wherein
the at least one control actuator is a braking actuator decoupled from a wheel of the vehicle, wherein a yaw moment generated by the braking of the wheel is determined for a front axle angle of the chassis and for equality of the reference yaw moment that was calculated with the effective yaw moment that was calculated.

12 . The steering control device according claim 7 , wherein
the input parameters include at least the specific drift of the front wheel axle and the specific drift of the rear wheel axle.

13 . The steering control device according to claim 12 , wherein
the specific drift of the rear wheel axle is set and determined according to a driving type identified by the control unit.

14 . The steering control device according to claim 8 , wherein
the input parameters comprise at least a mass distribution and an inertia distribution of the vehicle.

15 . The steering control device according to claim 1 , wherein
the lateral dynamic behavior model is written around a modal decomposition of a relationship between yaw and drift of the vehicle, at least one decomposition being associated with a steering angle actuator of the front wheel axle and at least one other decomposition being associated with a steering angle actuator of the rear wheel axle or to a control actuator of a decoupled braking system.

16 . The steering control device according to claim 15 , wherein
the lateral dynamic behavior model is configured to express the yaw rate as a function of each of the decompositions.

17 . The steering control device according to claim 16 , wherein
the control unit is configured to communicate with a plurality of sensors capable of measuring values retrieved subsequently by the control unit when driving the vehicle.

18 . A steering control method for controlling a direction of the vehicle equipped with the steering control device according to claim 1 , the steering control method comprising:
first calculating an effective yaw moment and a reference yaw moment; equalizing the effective yaw moment and the reference yaw moment that were calculated; and deducing at least one value that is to comply with at least one of a rear angle and a braking yaw moment as a function of a steering angle of the front wheels.

Assignees

• Nissan Motor

Inventors

• Boutron Olivier
• Martinez Didier

Classifications

• B62D6/003

  in order to control vehicle yaw movement, i.e. around a vertical axis (B62D6/007 takes precedence) · CPC title

• B60T2260/024

  Yawing moment compensation during mu-split braking · CPC title

• B60T8/1755 Primary

  Brake regulation specially adapted to control the stability of the vehicle, e.g. taking into account yaw rate or transverse acceleration in a curve (road vehicle drive control systems for control of driving stability otherwise than by controlling a particular sub-unit B60W30/02) · CPC title

• B60Y2400/81

  Braking systems · CPC title

• B60Y2400/84

  Rear wheel steering; All wheel steerings · CPC title