A robust motion coordination of two dynamically interacting systems with model uncertainties and bounded disturbances

A control scheme is presented for motion coordination of two dynamic systems interacting through a common port. The scheme incorporates dynamic constraints that result from the interaction involved in generating the control actions for the interacting systems. It resembles the conventional leader-follower control scheme with an added feature of reference model following. Robustness results for the control scheme, which guarantee L_∞-stability and error bounds in the presence of parameter uncertainties, actuator nonlinearities, and bounded disturbance, are a main contribution of the work. Robustness conditions are derived for a linearly state-dependent disturbance model, a nonlinearly state-dependent disturbance model, and a state-independent bounded disturbance model. For each case, a sufficient condition is obtained, using the small-gain theorem and an input-output approach