A position/force control for a soft tip robot finger under kinematic uncertainties

We consider the position and force regulation problem for a soft tip robot finger in contact with a rigid surface under kinematic uncertainties concerning the contact point location and the direction of free movement. The reproducing force is related to the displacement through a non-linear function whose characteristics are unknown but both the actual displacement and force can be directly measured. An adaptive controller is proposed and the asymptotic stability of the force error and estimated position error under dynamic and kinematic uncertainties is shown for the planar case. Simulation results for a 3-degrees-of-freedom planar robotic finger are presented.