A multiple-control strategy for robot manipulators

The characteristic behavior of three control schemes for robot manipulators is analyzed. The controller designs are based on three different control theories, i.e., classical control theory, variable structure systems theory, and model-reference adaptive control theory. The advantages and weaknesses of each of the controllers are identified. then, the three controllers are combined for form a bank of controllers for the study of multiple-control strategies. A restructuring control mechanism is suggested and used to coordinate the operational behavior of the controllers and to dynamically select the proper control action for a prespecified subtask. The superiority of the multiple-control strategy over the single-control strategy is demonstrated by presenting simulation results done on a 2-DOF robot arm. Graphical simulation results are also presented for illustration