讨论在 H∞ 混合灵敏度问题中加极点约束以避免零极点对消的设计问题 ,给出了乘性不确定性下的鲁棒极点约束的 L MI。讨论了极点约束问题中性能权函数的处理方法。给出了 H∞ 控制挠性系统的设计算例 Discusses the design problem of adding pole constraints in H∞ mixed sensitivity to avoid the pole-zero cancellation, and gives the LMI of the robust pole constraint under the multiplicative uncertainty. Discusses the handling method of the performance weight function in the pole constraint problem. The design example of H∞ control flexible system is given