Planetary perturbations make the earth's orbit about the sun irregular. 行星的摄动使得地球绕太阳的轨道是不规则的。
The concept of the non-fragile robust performance is presented for the design of the common control system with the perturbations of the controlled members and the controllers. 摘要为了解决在被控对象和控制器同时摄动时控制系统的设计问题，提出了一般控制系统的强鲁棒性能概念。
