Hybrid position force control of flexible manipulators on the basis of an equivalent spring model

A simple model and a hybrid position/force controller of constrained flexible manipulators having a heavy end-effector are presented by introducing a set of equivalent springs which represent all the flexibilities of a constrained manipulator. The dynamic relation of joint angles, vibration of the end-effector, and constraint force are derived on the basis of the proposed model. For measuring the vibrations and the contact force, accelerometers and a force sensor are used. Output signals of the sensors are fed back to the driving motors for controlling the position of the end-effector and the contact force. A feedback controller incorporating an observer is presented on the basis of the dynamic model. Simulation results are shown