Control of Systems with State and Control Constraints Based on Connected Reference Signals

Abstract

This paper considers characterization of the set of reference signals which are 'safe' for the systems with pointwise-in-time state and control constraints. The main idea is to construct two certain subsets such that for any reference input which is contained in the subset of the space of reference signals, avoiding constraints violation is equivalent to restricting the initial condition of a closed-loop system to the other subset of the state space. This paper also presents a technique to resolve tracking problems subject to state and control constraints. The method consists of adding to a primal closed-loop system a nonlinear device called a reference governor which manipulates the desired reference signal in order to fulfill the specified constraints. An admissibility condition on the initial state is satisfied and reference signal converges to an admissible region, the control scheme is proved to fulfill the constraints and set-point tracking requirements.