Design of Reference Governor for Linear Systems with Input Constraints

This paper presents a design method of the reference governor for a stabilizable linear system with input constraints. When the input has a constraint, the input saturation might happen and thus, the controller cannot work correctly. Furthermore, the output might diverge in the case of an open loop unstable system. To remedy this problem, the reference governor is proposed. The set-point control problem with control constraints is considered. In the proposed method, the behaviors of the states and input are predicted and the reference is modified so that the predicted input never exceeds the saturation limits and the modified one is closest to the given set-point command among the values which are achievable without the input saturation. The convergence of the newly generated reference trajectory is proved. Simulation results are included to verify the performance of the proposed method. Copyright c ©2005 IFAC.