Abstract
In this paper we consider a design problem of robust servo systems with quadratic stability using observer-based output feedback and treat the case where there exist uncertainties both in the state matrix and the input matrix. This robust feedback controller is designed so that (1) the closed loop system is quadratically stable, (2) its output tracks a command step input, and (3) desirable output responses can be achieved. First, we correct those mistakes found in our previous results related to this problem. Next, we derive a design algorithm of robust servo systems with quadratic stability. With this design algorithm a specification of tracking characteristics and improvement of robust stability of the resulting system can be performed almost independently. Finally, a design example is shown based on the algorithm.
