Design of Delayed Output Feedback of Linear Time-Varying Systems With Applications to Spacecraft Magnetic Attitude Control

摘要

This paper studies the low-pass filter (LPF) design in the delayed output feedback control of linear time-varying systems. In the case of linear time-invariant systems, the safe implementation of the distributed delay (integral terms) needs to introduce an LPF in the control loop and the LPF can be designed by using the pole assignment method. However, the parameters of LPF in linear time-varying systems are time-varying and the existing design methods are not applicable. This paper provides a new method to design the LPF for time-varying systems. The designed LPFs are such that, if the closed-loop system without LPF is uniformly asymptotically stable, then the closed-loop system with LPF is also uniformly asymptotically stable, while the later is robust with respect to approximated numerical implementation. Finally, simulations are carried out on a magnetic attitude control system and the results verify the effectiveness of the methods proposed in this paper.