Designs of Minimal-Order State Observer and Servo Controller for a Robot Arm Using Piecewise Bilinear Models

This paper proposes a servo control system based on a minimal-order state observer for nonlinear systems approximated by piecewise bilinear (PB) models. The design method is capable of designing the state observer and the servo controller of nonlinear systems separately. The approximated system is found to be fully parametric. The input-output (I/O) feedback linearization is applied to stabilize PB control systems. Although the controller is simpler than the conventional I/O feedback linearization controller, the control performance based on PB model is the same as the conventional one. The PB models with feedback linearization are a very powerful tool for the analysis and synthesis of nonlinear control systems. We apply the control method to a robot arm model. An example confirms the feasibility of the our proposals.