COMPLIANT CONTROL OF A 2-LINK FLEXIBLE MANIPULATOR BY CONSTRAINT HAMILTONIAN SYSTEM

Two essential tasks of robotic manipulators are characterized by posit ion-to-position movement and contact with external environment. The co ntact usually results in the generation of external forces in the end- effector of the manipulator, which always modify the dynamic behavior. Consequently, issues of appropriate modeling techniques and effective compliant control strategies arise. In this paper, a new approach emp loying the framework of constraint Hamiltonian system is proposed for the compliant control of a two-link flexible manipulator with surface constraints. Two non-linear controllers consisting of force part and p osition part are derived from a constrained Hamiltonian system, follow ed by the formulation of corresponding linear feedback controllers tha t satisfy the Lyapunov stability of the total Hamiltonian system which possesses the non-linear controllers. The compliant control strategy is accomplished by steering the end-effector of the flexible manipulat or onto the constraint surface with the linear controllers, and subseq uently by executing imposed desired motion with the non-linear control lers. Computer simulations are undertaken in order to demonstrate the analytical formulation and the effectiveness of the proposed control m ethodology. (C) 1997 Elsevier Science Ltd.