工程机械各种工作状态通常以其“二次效应”反映出来，典型的二次效应有振动、噪声、冲击、温度、压力及应力应变等。通过电测手段可将上述物理量以电讯号测取，此类动态测试信号称为工程信号。 工程上的实测信号虽然可以直接判读获得有用的信息，但不能满足工程上的需要。因此 A variety of working conditions of construction machinery are usually reflected in their “secondary effects”. Typical secondary effects include vibration, noise, impact, temperature, pressure and stress and strain. By means of electrical measurements of the above physical quantities can be measured by electrical signals, such dynamic test signal is called engineering signal. Although the measured signal in engineering can be directly read to obtain useful information, but can not meet the engineering needs. therefore