POSITION FORCE CONTROL OF ROBOT MANIPULATORS WITHOUT VELOCITY/FORCE MEASUREMENTS/

The authors consider the problem of designing a position/force control ler for robot manipulators during constrained motion. The proposed con trollers are based on exact knowledge of the system dynamics and do no t require measurements of link velocity and end-effector force. The el imination of velocity measurements is accomplished by two different me thods: (1) a model-based velocity observer, and (2) a high-pass filter ing technique. Both of the controllers also include an open-loop force control strategy to achieve semi-global exponential end-effector posi tion/velocity/force tracking. A simulation study for a two-link planar robot is included.