Control of a flexible arm with input dead zone by a passivity based adaptive output feedback

In this paper, we deal with a tip position control problem of a flexible arm with dead zone for the control input torque. A design method of a passivity based adaptive output feedback control for nonlinear nonminmum-phase flexible arm systems will be presented. To realize an adaptive output feedback control for nonminimum-phase control systems, we introduce a parallel feedforward compensator (PFC) so as to satisfy the OFEP (Output Feedback Exponentially Passive) conditions and design an adaptive feedforward input with a structure of neural networks in order to remove undesired vibration and the steady-state bias error from the PFC output and input dead zone. The effectiveness of the proposed method is examined through experiments for a flexible arm with dead zone.