1.引言机器中的机械和电气系统,在运转期间,都会产生次级效应,例如:振动、噪声、热、温度以及电和磁辐射等。机器内部产生的这类次级效应,通常传递到机器外部,并附带机器内部变化的信息。如果机器外部的观测者能测量和解释这些效应,就能不用内部传感器直接洞察机器内部的运转质量。信号诊断法,最初集中于声学和振动技术,目 1. Introduction Mechanical and electrical systems in machines have secondary effects during operation such as vibration, noise, heat, temperature and electrical and magnetic radiation. Such secondary effects generated inside the machine are usually passed to the outside of the machine with incidental changes in the machine. If observers outside the machine can measure and interpret these effects, it is possible to gain direct insight into the quality of the operation inside the machine without an internal sensor. Signal Diagnostics, initially focused on acoustic and vibration technology, aims