Conference article

Feedforward control based on inverse dynamic plant models (linear or nonlinear) is a suitable method to enhance set-point tracking performance of control systems. In reality actuators always have limits; but limiting functions can not be inverted. A common approach to handle this issue is to invert the unlimited plant model and detune the feedforward filter in order to stay always in between the actuator limits. This approach causes a loss in performance for rapid set-point changes; because the actuator range is not entirely used. In this article a rather simple but powerful method is presented; which overcomes this performance issue for many types of plant models. Actuator limits are fully exploited; and the obtained trajectories are close to optimal ones. Simulation and measurement results demonstrate the usability of the proposed feedforward structure.

Set-point tracking; model inversion; actuator saturation; nonlinear control; model-based control; anti-windup