VARIABLE-STRUCTURE CONTROL OF 2 MANIPULATORS HANDLING A CONSTRAINED OBJECT

The control of two manipulators handling a constrained object involves the control of the position of the object, the internal force used to grasp the object, and the constraint force due to the constraint surf ace. The robustness of the controller must be guaranteed when the syst em faces parameter uncertainties and/or external disturbances. In this paper, a variable structure control law is proposed. This controller guarantees the asymptotic convergence of the position of the object, i nternal force, and constraint force to their desired values when uncer tainties on the parameters and external disturbances are present in th e system. Simulation results for two planar robots moving an object al ong a horizontal plane illustrate the fact that the proposed controlle r achieves the desired asymptotic tracking.