随着工程应用的需要 ,基于模型的故障诊断技术已经成为可靠性工程的重要研究内容 .在基于模型的故障诊断技术中 ,定性模型与定量模型各有其优缺点 ,一个实用的系统需要将二者有机地结合在一起 .给出一种由定量模型产生定性模型的方法 .最后给出一个二阶系统的算例 ,说明本方法具有较大的工程实用价值 . With the needs of engineering application, the model-based fault diagnosis technology has become an important research topic in reliability engineering.In the model-based fault diagnosis technology, the qualitative model and the quantitative model each have their own advantages and disadvantages, and a practical system needs two Are combined organically.This paper presents a method of producing a qualitative model from a quantitative model.An example of a second-order system is given, which shows that the proposed method has great practical value.