Optimized Input-Shaped Model Reference Control on Double-Pendulum System

This paper presents an optimized input-shaped model reference control (OIS-MRC) for limiting oscillation of multimode flexible systems. The controller is analyzed by using it to control an uncertain, time-varying double pendulum using a linear single-pendulum reference model. Single-and double-pendulum dynamics are presented, and the significant natural frequency ranges of the double pendulum are calculated. A Lyapunov control law using only the first mode states of the plant is obtained. An optimization technique is used to obtain the OIS-MRC controller parameters that realizes the shortest time duration, while meeting a set of design constraints. The oscillation suppression, control effort reduction, and disturbance rejection performances of the proposed OIS-MRC controller are tested via numerical simulations and experiments. The OIS-MRC achieves a robust oscillation suppression performance, while reducing the rise time.