| In this dissertation, the active delay output feedback control techniques are presented for high-performance flexible servo systems. Among these delay-related control techniques, the delay transform with finite design region principle play as the fundamentals of the generalized delay-based infinite dimensional control algorithms. The former is a way to realize any improper polynomial transfer function, which is physically unrealizable in conventional finite dimensional domain. And the latter serves as the systematic and general closed-loop stability and performance criteria. Since the improper controller can be realized through delay transform, the full state feedback control is physically realizable by delay-based output feedback with equivalent performance. And this technique is proved to have much better performance than the conventional observer-based or compensator-based output feedback. However, due to the introduction of delay, although the steady-state response is as perfect as full state feedback, the transient response deterioration is inevitable. This calls for a remedy called initial function compensation technique for delay-based controller and it has been proved that the transient response deterioration can be eliminated. Furthermore, to achieve high-performance flexible servo systems, control of non-minimum phase system is not uncommon, which is very complicated in practice. The so-called internal model modification technique solves this problem perfectly and combined with the delay-based output feedback, this new technique becomes a promising output feedback technique for high-performance flexible servo systems. |
