A combination of feedforward and feedback for the control of the nonlinear benchmark Inertia Wheel Pendulum

This contribution is about the combination of a feedforward and feedback controller in order to force a nonlinear plant along a sufficiently smooth reference curve. This approach includes a feedforward part in the framework of Port-Controlled Hamiltonian Systems with Dissipation (PCHD systems). PCHD systems have turned out beneficially for the design of nonlinear controllers and provide special properties for the stability analysis of equilibrium points. By means of feedback control one may overcome model errors and disturbances for a real application. A passivity-based controller, which is designed for the PCHD error dynamics, exploits the mathematical structure of the system and forces the tracking error to zero. The combination of the feedforward and feedback part leads to a controller, which achieves good tracking behavior, cancels initial errors and rejects disturbances from the environment. The derivation of a control law which includes a feedforward part and a feedback controller will be shown for the nonlinear underactuated benchmark example Inertia Wheel Pendulum.