Development of Feedforward Control Algorithms for Active Suspension 920270
A Slow Active Suspension system has the advantage of requiring less energy than a Full Active Suspension system. But for improving vehicle's attitude control, feed-forward control becomes of paramount importance.
This paper describes the control algorithms utilized in the Slow Active Suspension system that Toyota has just made available on the Japanese market. Special control items specifically developed for this system are;
The parameter Kwt, which is the ratio between the estimated differential value of lateral acceleration from steering angle velocity and that from lateral acceleration sensor in order to realize fast response to transient roll control,
Side Slip Judgement, which prevents the feed-forward errors in the case of changing co-efficients of surface friction,
Heave control, which prevents the vertical motions caused by heave disturbance force in the suspension cylinders during high-G turns.
By means of these algorithms, it has been possible to realize a Slow Active Suspension system that not only raises ride comfort but also accomplishes stable maneuverability and excellent attitude control of the vehicle.