Compensation of friction in mechanical drives for a three fingered robot gripper

Performing fine manipulations with multifingered robot hands makes high demands on the control algorithms and the speed of the control computer. Mainly nonlinear friction problems and plant uncertainties require intensive fine-tuning of a controller. This paper gives insight into the frictional behaviour of geared finger links. The behaviour has been approximated by a friction model. Considering the estimated system parameters two kinds of controllers are developed: a simple PD controller with switchable I-part and a PD-controller with a fuzzy friction compensation working in parallel. The results of both controllers are presented and compared in this paper.