Abstract
This paper presents designs of decoupling control systems based on the H∞-mixed sensitivity problems.
H∞-control has been studied as an effective method for multi variable systems. However, a decoupling control design based on the H∞-control is not well known. We present a design method based on the H∞-mixed sensitivity problems where the decoupling performance can be obtained if the weighting functions are chosen properly.
First, designs of one-degree-of-freedom control systems with state feedback or output feedback, will be stated. The design, of state feedback control is based on FI (Full Information) Problem and the design of output feedback control is based on DF (Disturbance Feedforward) Problem.
Next, designs of two-degree-of-freedom control systems with state feedback and output feedback, will be stated. The design consists of two stages. The first stage is to design a feedback compensator. The second stage is to design a feedforward compensator for the new plant which consisits of the true plant and the feedback compensator. This problem is equivalent to DF Problem. Even if decoupling can not be obtained with the feedback compensator, it can be obtained through the feedforward compensator.
