Development of Steering Laws to Assist the Driving of a Independent Front and Rear Steering Vehicle

This paper proposes a control strategy to control the yaw rate of a 2-independentsteering-gears vehicle operated by a driver. The approach is based on adaptive techniques to account the slip effects. An extended kinematic model is used which takes into account slipping effects through side-slip angles. A 3-steps state observer is proposed to estimate a characteristic parameter defining the tyre-ground contact. This state observer use only the value of control variables and the yaw rate measurement of the vehicle. Thanks to the proposed approach the driver can safely steer the 2steering-gears off-road vehicle using one steering actuator without losing control at high speeds as will be the case with two independent steering actuators.