抄録
We propose a design method of feedforward type motion control system that provides desired response of yaw rate and lateral acceleration for a four wheel steering vehicle (4 WS).
This paper firstly presents three design methods of yaw rate, lateral acceleration and D* (which is defined as a linear combination of yaw rate and lateral acceleration) control system respectively. These systems are synthesized by model matching control or model following control.
In order to verify the effectiveness of the proposed method, the computer simulation of vehicle motion was carried out, resulting in good agreement between a reference model and a controlled vehicle. Futhermore, driving tests were conducted with an experimental vehicle having electronically controlled rear wheel steering mechanism. In step response test to steering wheel input and lane change test, the responses of the controlled vehicle matched with the model satisfactorily, and in free response test at the vehicle speed of above 100km/h, the settling time of the controlled vehicle was reduced by more than 50%.
From these results, it has been confirmed that the proposed design method of rear wheel angle control system is useful in improving maneuverability and stability of the vehicle.
