A design method of the control system using double feedback control with low sensitivity and robust stability by independent design of the controllers

In this paper, we consider a design method of the control system using double feedback control that provides low sensitivity with robust stability for single-input and singleoutput continuous time-invariant systems by independent design of the controllers. If the control system has low sensitivity characterinstics, then the steady state error for the reference input and influence of the disturbance for the output become small. However, It is said that the low sensitivity control has bad robust stability characteristics. Yu et al. propose a design method of the control system called the double feedback control system that provides low sensitivity characteristics and robust stability by using many controllers. However, Yu et al. does not considered how to design each controllers, independently. In this paper, we expand the result of Yu et al. and propose a design method of the double feedback control system that each controller is designed, independently.