抄録
In previous paper, we extended the designing method proposed by Keel et al., which originated from robust eigenvalue assignment, to a system with time-varying uncertainties which are exhibited by the linear combination of time-varying parameters and time-invariant matrices specifying the structures of uncertainties. Moreover, we proposed a novel algorithm to obtain a state feedback that achieved a robustly stable closed-loop system.
In many practical cases, it may be impossible to measure all of the state variables in the system. It shall be required to stabilize the system by use of output feedback controller.
This paper presents a new method for robust stabilization of the above-mentioned system by means of output feedback controller with low-order compensators, in which the closed-loop eigenvalue assignment is relaxed, that is, discrepancies between the desired and the achieved closed-loop eigenvalues are permitted. Based upon the Gronwall's lemma, a sufficient condition with respect to the uncertainty tolerance is also prepared for the asymptotical stability of the closed-loop system. Furthermore, we state the relation between the robustness of the stability and the order of dynamic compensator. For example, designs of lateral autopilot system of a missile are shown.
