中文摘要：

PMC模型是一种基于测试的系统级故障模型.针对传统诊断算法的弱点,作者于2003年建立起了PMC模型方程诊断算法的框架.本文的主要工作是：（1）对以往的理论进一步补充完善;（2）给出一个直接求绝对故障基的简便方法;（3）通过引入直和的概念,将高维PMC故障模型分拆成低维模型进行诊断;（4）举例说明方程诊断算法的应用.

英文摘要：

PMC model is a kind of system-level fault model based on test. To counter the weakness in traditional diagnosis algorithm, we have set up a framework of equation diagnosis algorithm for PMC model in 2003. The chief works in this paper are as follows： （ 1）The past theorem is further replenished and complemented; （2） A simple and convenient method for directly getting absolute fault base is given; （3）By introducing the concept of direct stun,more dimensions PMC fault models are separated into less dimensions models to diagnosis; （4）Equation diagnosis algorithm＇s applications are illustrated by examples.