On the effect of compliance in robotic contact task problem

Generally, in most dexterous manipulation tasks the manipulator undergoes a transition from free motion to contact configuration with its environment. An example can be the exploratory unconstrained motions of the force guided manipulator for establishing contact with an environment. This transition usually involves the impact stage. The impact usually results in an unstable performance of the closed-loop controller of the manipulator. One of the main remedies to achieve a stable closed-loop control of the manipulator is to introduce some compliance property into the closed-loop system. Based on the second method of Lyapunov and the theory of guaranteed stability of uncertain systems, this paper presents results on showing the effect of compliance in increasing the stability bounds of the manipulator during the impact phase. Experimental results are also presented to demonstrate the effect of compliance in the stable response of the manipulator during the impact phase