Robust synthesis of linear servomechanisms

Abstract In our previous paper (Hosoe, 1980), the notion of structural system type was proposed and two methods were derived for determining the types of given systems. In this paper we use these results to the synthesis of structural type[l 1 ,…,l m ] unity feedback systems. The controller is composed of a stabilizer and a servo-compensator. The purpose of the stabilizer is simply to stabilize the loop. The servo-compensator is connected to the plant in series to improve the system type. The synthesis of the servo-compensator is carried through the repetition of steps at which l i is increased by one. In connection with the synthesis problem, we investigate the structural observability of series connected systems in detail.