Position Control of Flexible Manipulator based on Nominal Stiffness Design of Load Side Observer

Abstract

When controlling a robot arm that includes flexible structures such as space manipulators, there occur problems such as vibration during operation and errors between commands and responses. As a result, it is difficult for operators to accurately move the manipulator, and hence precise work cannot be realised. Therefore, a control method is required to solve these problems. In this paper, a method is proposed to suppress the vibration of the flexible robot arm and enable high precision control by changing the apparent stiffness of the flexible structure based on the nominal stiffness design of the load side observer. Also, input shaping is considered to realise robust control. Simulation and experimental results of the position control of two mass resonant systems showed that the flexible structure induces vibration and that errors occur in the response. By adopting the proposed method, the above-mentioned problems are solved, and the effectiveness of the method is shown.