Control and Parameter Optimization of Flexible Robots*

A hierarchical control concept for flexible robot manipulators is presented. The equations of motion are derived using the multibody system method, incorporating flexible links equipped with surface bonded actuating and sensing devices. Exploiting the structure of the dynamic model, the control concept allows combination of any joint level control for the gross motion of the manipulator with decentralized linear control of the elastic deformation of each flexible link. Therefore, the approach is capable of solving both the problem of fast and precise point-to-point motion, with acceptable vibration characteristics, and the problem of accurate trajectory tracking of the end-effector. Control parameters are found through parameter optimization. In order to verify the proposed control strategy, a SCARA robot with one flexible link is considered.