修正型可變結構設計與其應用在非線性可靠度控制之研究

Abstract

本論文針對衛星系統及機器手臂模型具有不確定參數及外界干擾提出一種修正型的可變結構控制律來完成姿態控制與軌跡追蹤的任務。此控制律能大幅減輕由切換式可變結構控制律所產生的切換現象，同時我們也證明所提出之控制律能將飽合式可變結構控制律只能達到最終有界的性能提升到漸進穩定的水準，模擬結果顯示了所提出之修正控制律的優點。此外，本論文也利用可變結構控制的概念來設計可靠度控制器並將其應用到衛星及飛彈系統。所提出之設計方式不但能達到良好的可靠度性能，而且可大幅減輕傳統可靠度控制必須求解Hamilton-Jacobi方程式之計算負擔。

A modified Variable Structure Control (VSC) scheme is developed in this paper for the attitude and position tracking of satellite and robot manipulator, respectively, under parameter uncertainties and external disturbances. The modified VSC laws are continuous, which are shown to be able to alleviate chattering drawback produced by sign-type VSC controllers and improve the performance of saturation-type ones from the level of uniformly ultimate boundedness to the one of asymptotic stability. Simulation results demonstrate the benefits of the proposed VSC design scheme. In addition, we also develop a reliable VSC scheme and apply it to satellite stabilization and missile bank-to-turn tracking. It is shown that the objectives can be achieved even when the system experienced some prespecified actuators outage. In contrast to the existing reliable control, the proposed scheme can alleviate the computational burden for solving the Hamilton-Jacobi equation, which is a difficult and essential part of conventional reliable schemes.