频率特性极坐标图的定性画法

频率特性的极坐标图是分析控制系统稳定性的一个重要手段，但绘制其极坐标图通常较困难，特别是对于高阶含有不稳定零、极点的系统.目前还没有见到适于绘制包括最小相位系统、不稳定系统频率特性极坐标图的统一的定性绘制方法．本文即给出一种统一的定性绘制方法．

Qualitative Drawing of Frequency Characteristic in Pole Coordinate

The drawing of frequency property in pole coordinate system is an important way to analysisthe stability of control system. But it is very difficult in the drawing of frequency property in polecoordinate system,especially to the higher-derivative system including non-stead zero-points andpole-points. Now there are no report about the common qualitative drawing method which is suitablefor the rninimum phase system and non-steady system. The common drawing method is given in this paper.