title: Performance limitations in the tracking and regulation problem for discrete-time systems.
abstract: In this paper, the optimal tracking and regulation performance of discrete-time, multi-input multi-output, linear time-invariant systems is investigated. The control signal is influenced by the external disturbance, and the output feedback is subjected to an additive white Gaussian noise (AWGN) corruption. The tracking error with channel input power constraint and the output regulation with control energy constraint are adopted as the measure of tracking and regulation performance respectively, which can be obtained by searching through all stabilizing two-parameter controllers. Both results demonstrate that the performance is closely related to locations and directions of the nonminimum phase zeros, unstable poles of the plant and may be badly degraded by external disturbance and AWGN.
authors.affiliation: College of Automation, Huazhong University of Science and Technology, Wuhan 430074, PR China; College of Mechatronics and Control Engineering, Hubei Normal University, Huangshi 435002, PR China.
authors.forename: Xiao-Wei
authors.initials: XW
authors.lastname: Jiang
authors.affiliation: College of Automation, Huazhong University of Science and Technology, Wuhan 430074, PR China. Electronic address: zhguan@mail.hust.edu.cn.
authors.forename: Zhi-Hong
authors.initials: ZH
authors.lastname: Guan
authors.affiliation: School of Mathematics and Statistics, Anyang Normal University, Anyang 455000, PR China.
authors.forename: Fu-Shun
authors.initials: FS
authors.lastname: Yuan
authors.affiliation: College of Mechatronics and Control Engineering, Hubei Normal University, Huangshi 435002, PR China.
authors.forename: Xian-He
authors.initials: XH
authors.lastname: Zhang
keywords: MIMO discrete-time systems; Nonminimum phase zeros; Output regulation; Reference tracking; Unstable poles