Robust regulation and trajectory tracking for flexible robots by using piezoelectric actuators

Abstract

We show how thin planar piezoelectric actuators can be used for the robust regulation and trajectory tracking of flexible robots. The analysis is restricted to single-link flexible robot arms, having a planar 'sandwich' structure, constituted by two piezoelectric films, mounted on a thin elastic support. The motion of the structure can be approximately described by finite dimensional, linear, time-invariant equations. The proposed controller provides the regulation of the generalized coordinates, which describe the structure shape, to zero or to constant reference signals with zero steady-state error, and the tracking of ramp reference signals with a finite, arbitrarily bounded, steady-state error, even when variations of the structure parameters occur. Some simulation results are reported.