On the optimal control of flexible manipulators

Abstract This paper presents a simple technique based on numerical optimization to solve trajectory control and time optimal control of multiple-link robotic arms with flexible links and joints. The proposed technique finds the joint torques required to move the end-point from rest to rest through a specified path. In trajectory control problems the desired position of the payload is given versus time, while in time optimal control problems the path and the constraints on the joint torques are known. Inverse dynamics of flexible manipulators is non-causal because the point for which the prescribed motion is specified and the application points of control torques are connected by deformable bodies. Non-causality is taken into account via consideration of pre-actuation and post-actuation in the solution procedure.