Abstract: This paper describes an expanded system for a servo
system design by using the Loop Shaping Design Procedure (LSDP).
LSDP is one of the H∞ design procedure. By conducting Loop
Shaping with a compensator and robust stabilization to satisfy the
index function, we get the feedback controller that makes the control
system stable. In this paper, we propose an expanded system for a
servo system design and apply to the DC motor. The proposed method
performs well in the DC motor positioning control. It has no
steady-state error in the disturbance response and it has robust
stability.