Abstract
This paper considers a tracking problem for a linear system with norm bounded time-varying uncertainties. The aim is to design a controller so that the system is quadratically stable for all allowable uncertainties and its output tracks the reference input which is represented as smoothly differentiable function as closely as possible. A controller having this property is given as a two-degrees of freedom controller. The feedback controller is designed by solving Riccati equations and the feedforward controller is designed as an inverse system of the nominal system. The conditions under which the system asymptotically tracks any constant reference input are considered. The method is applied succesfully to a position control system of a mechanical printing machine.
