ACC On the E ect of Compliance in Robotic Contact Tasks Problem

Generally, in most dexterous manipulation tasks the manipulator undergoes a transition from free motion to contact con guration 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 (i.e. through hardware or through feedback control laws) [3], [8] , [4]. Based on the Second Method of Lyapunov and the theory of guaranteed stability of uncertain systems, this paper presents results on showing the e ect of compliance in increasing the stability bounds of the manipulator during the impact phase. The paper also presents discussions on how the e ect of compliance in the model of mechanical manipulator can be studied in the closed-loop stability. Experimental results are also presented to demonstrate the e ect of compliance in the stable response of the manipulator during the impact phase.