On Transient Performance For Servomechanism Problem Of Linear Discrete-Time Systems With Input Saturation

Transient performance of the linear output regulation problem with input amplitude saturation is the core topic of this paper. Due to the oncoming digital control tide, it is significant to study the transient performance for discrete-time linear output regulation. The input amplitude saturation makes this topic more practical.In this thesis, the output regulation is laid under the local regulation framework due to the saturation. And then the composite nonlinear regulators are constructed via state feedback and output feedback based on the so-called composite nonlinear feed-back technique. The composite nonlinear regulator is an additive combination of two parts, a linear part and a nonlinear part. The linear part of the composite nonlinear reg-ulator itself independently solves the output regulation with input saturation generating quick transient responses but large oscillations. Aiming at a better closed-loop tran-sient performance with input constraints, the nonlinear part with well-tuned parameters is introduced to smooth the overshoots and undershoots that are caused by response quickness.The thesis proves that the composite nonlinear regulator solves the linear discrete-time local output regulation problem with input amplitude saturation. At the same time, the extraly introduced nonlinear part in the composite regulator does not alter the solvability conditions of the output regulation problem. The last part of this thesis demonstrates the versatility of the composite nonlinear regulator design schedule for transient performance improvement by illustrating a numeric example.