Design and Vehicle Implementation of Preview Active Suspension Controllers

Active suspensions influencing the vertical dynamics of vehicles enable the improvement of ride comfort and handling characteristics compared to vehicles with passive suspensions. If the road height profile in front of the car is measured using vehicle sensors, more efficient control strategies can be applied. In this brief, two model predictive approaches for preview active suspension controllers are proposed and compared to the well-known optimal preview control approach. The considered active suspension consists of low bandwidth actuators in series with the spring and passive dampers. Equations of a linear full-car model are derived. The first model predictive controller optimizes the actuator displacements on a nonequidistant grid over the preview horizon. The second controller optimizes trajectories for heave, pitch, and roll of the vehicle body over the preview horizon using a quadratic program. Therefore, a model inversion is presented. The trajectories are formulated as a summation of nonequidistant B-spline basis functions and constraints on the input are incorporated in trajectory generation via the inverse vehicle model. Simulation results are presented and vehicle implementation using recorded road height data is conducted.