采样系统的H∞混合灵敏度设计

由于流行的提升法实际上并不适用于采样控制系统的H∞最优设计,本文提出一种基于频率响应概念的新的离散化H∞设计方法.文中结合S/T混合灵敏度问题,分析说明了这种离散化方法,并从鲁棒稳定性和性能两方面对设计结果进行了定量的验证.文中还与提升法的H∞设计进行了对比,指出由于提升变换需要进行回路转移,改变了标准H∞问题中的结构关系,因而设计结果并不理想.

H-infinity mixed sensitivity design for sampled-data systems

Because the popular lifting technique is not suitable for H-infinity optimal design of sampled-data control systems,a novel discretization H-infinity design method based on the frequency response concept is proposed in this paper.Firstly,this discretization method is presented in the context of a typical S/T mixed sensitivity problem.Both the robust stability and performance of the design of the proposed method are verified quantitatively.A comparative design by lifting is also given for the S/T problem.Finally,it is pointed out that the structure of the standard H-infinity problem is changed by loop-shifting during the lifting transformation,and the resulting performance of the lifting design is not desirable.