Abstract
The present paper presents a new solution for the stabilization and disturbance attenuation problems of the oscillating eccentric rotor (OER), an extensively studied non-linear under-actuated mechanical system. Designing control law for such systems is a challenging task owing to the under-actuation property, which poses problems in exact feedback linearization. Presented non-linear controller design exploits the recently introduced dynamic surface control technique in a novel manner. The task of the controller is not only to de-spin the rotor but also to stop the translational oscillations. The design procedure is simpler and more intuitive than currently available integrator backstepping or energy-shaping-based designs. Stability is analysed by decomposing the system into a cascade of several subsystems. Advantages over existing controller designs are analysed theoretically and verified using numerical simulations. The design is found to attenuate oscillation amplitude effectively in the presence of an external sinusoidal translational disturbance besides aggressive stabilization.