Practical adaptive control of actuated spatial mechanisms

A new model referenced adaptive control scheme for a general actuator-link assembly based on the Lyapunov stability criterion is presented. A general model of the actuator and link dynamics and constraints is formulated as an integral structure. Application of a state feedback gain introduces the adjustable system. The model and control are formulated to address such physical considerations as motor saturation, static friction, unknown loads and uncertain plant parameters. This control scheme is shown to solve several current problems in application of adaptive control to a manipulator system; namely it accounts for the effects of actuator dynamics and constraints, and the static error due to friction and uncertain steady state loads. This scheme has been simulated and demonstrated to be robust over a variety of practical conditions. Finally the practical realization of this algorithm is discussed with reference to the Pennsylvania Anthropomorphic Robot Manipulator currently under construction.