Measurement-scheduled control for the RTAC problem

The RTAC (rotational/translational actuator) nonlinear control design benchmark problem is addressed using a multiobjective control methodology based on linear matrix inequalities and robust control. The approach hinges on the search for quadratic Lyapunov functions ensuring various specifications (stability, L/sub 2/-gain, command input and output peak bounds) to hold for the closed-loop system. The resulting output-feedback controller is measurement-scheduled, its state-space matrices depend on the measurement vector in a nonlinear fashion. We evaluate the performance of our design with various simulations and predicted trade-off curves.