Force and transition control with environmental uncertainties

A new sensor-referenced control method for robot impact control and force regulation with environmental uncertainties is developed in this paper. The robot dynamic model is feedback linearized and decoupled for the free motion mode, the phase transition, mode as well as the constrained motion mode. After introducing an impact model, together with the proposed positive acceleration feedback control scheme, a stable contact can be made with a nonzero impact velocity. During the impact, large impact forces and bouncing can be avoided. Moreover, the output force can be regulated after contact is established. The scheme was implemented and tested on a 6 DOF PUMA 560 robot arm. The comparison with other control methods for robot phase transition is presented. The experimental results clearly demonstrate the advantages of the proposed method