Vibration absorption control of force-controlled manipulators on the basis of an equivalent spring model

A simple model considering flexibility of constrained force-controlled manipulators is proposed by introducing a set of equivalent springs. On the basis of the proposed model we derive a controller, which compensates the vibrations of the responses of the contact force. For measuring the vibrations and the contact force, accelerometers and a force sensor are used, respectively. Output signals of the sensors are fed back to the driving motors for controlling the position of the end-effector and the contact force. The proposed controller is useful from the practical point of view, because there is no need to change the usual controllers and to construct complicated nonlinear observers. Experimental results are shown