Adaptive Decentralized Control of a 4-DOF Manipulator with a Flexible Arm

A decentralised adaptive control approach for the control of a 4-DOF manipulator with a long flexible arm is discussed. Each link of the manipulator is treated as a simple inertial subsystem with a disturbance torque representing the unmodeled dynamics. A new controller is presented to suppress the elastic vibration of the flexible arm; the control laws do not rely on the exact knowledge of the dynamic and payload parameters, since disturbance estimation and rejection techniques are used. The controller has a very simple structure, which makes the real time control relatively easy to implement. The simulation results of the system show that the controller closely tracks the desired input under various configurations, payloads and input reference sigals.