Tracking Control of Constrained Robotic Systems under Uncertain Initial Conditions

This paper proposes a robust adaptive tracking control approach for robotic systems with deferred and time-varying (DTV) output constraints. By introducing an error-shifting transformation into control synthesis, a new tracking control scheme is developed for robotic systems in the presence of DTV output constraints and uncertain initial tracking conditions as well as non-vanishing disturbances. In contrast to existing works that require the constraints be satisfied from the beginning of system operation, the proposed method is able to deal with the situation that the output constraints are violated initially, rendering the method more flexible and more widely applicable. The effectiveness of the presented control strategy is verified by theoretical analysis and numerical simulation.