A fast weight optimization method in H∞ Loop-shaping Design for single input single output system

A weight optimization method for single input single output system H_∞ Loop-shaping Design is addressed. Using the proposed method, suboptimal weight which meets constraints of desired loop-shaping and grade of amplitude-frequency curve of weight can be obtained. Acceptable range of amplitude-frequency curve of weight is also given, in which maximum robust stable margin is kept. Designer can choose low order whose amplitude-frequency curve is within this range no matter how much fitting error between the selected weight and optimal amplitude-frequency is. Simulation results show that the proposed method can maximize the robust stable margin while ensuring loop shape of open loop plant lives in a pre-defined region and grade of weight less than the value given by designer. Stable lightly damped pole-zero cancellation is prevented, which is attributed to grade constraint of amplitude-frequency curve of the synthesized weight. And corresponding program is at least 100 times faster than similar optimization algorithm which completely is based on linear matrix inequality technology.