On The Active Input Output Feedback Linearization of Single Link Flexible Joint Manipulator, An Extended State Observer Approach.

Traditional input-output feedback linearization (IOFL) is an essential part of nonlinear control theory and a valuable tool in solving class of problems possessing certain constraints. It requires full knowledge of system dynamics and assumes no disturbance at the input channel and no system's uncertainties. In this paper, an Active Input Output Feedback Linearization (AIOFL) technique based on extended state observer which is the core part of the Active Disturbance Rejection Control (ADRC) paradigm is proposed to design a feedback linearization control law. This control law transforms the system into a chain of integrators up to the relative degree of the system. The proposed AIOFL simultaneously cancels the generalized disturbances (exogenous disturbance and internal uncertainties) and delivers the estimated system's states to the nonlinear state error feedback of the ADRC. Verification of the outcomes has been achieved by applying the proposed technique on the ADRC of Flexible Joint Single Link Manipulator(SLFJM). The results showed the effectiveness of the proposed tool.