摘要
本文介绍的求闭环频率特性的图解法，其特点是不用Ｎｉｃｈｏｌｓ图线或等Ｍ圆、等Ｎ圆图，而是通过向量叠加的办法，由开环频率特性求闭环频率特性。该方法计算量少，简单方便，适用于自动控制系统的分析与设计。
In this paper, the graphic method to determine closed -loop frequency characteristic is introduced. The feature of this method is that the vector superposition method is used to obtain the closed -loop frequency characteristic from the open-loop frequency characteristic. instead of using NICHOLS chart, constant M circles and constant N circles. The method given here has less amount of calculation, is very simple and suitable for the analysis and design of automatic control system.
