Engine fault detection using angle domain signal envelope algorithm

Abstract

Vibration signals from internal combustion engines contain strong noise and nonstationary characteristics in the time domain, which cause difficulties when attempting to detect and diagnose incipient faults in engines using signal features. In order to improve the success rate and broaden the applicability of engine incipient fault detection, a new concept of angle domain signal envelope analysis is proposed. The new method uses an encoder to acquire an engine rotational vibration signal using equal angle sampling. Angle domain synchronous averaging is used to denoise the original signal, and engine incipient fault features are extracted by the angle domain signal envelope algorithm. Experimental results using signals recorded from an engine with a connecting rod bearing with improper fit clearance have shown that the angle domain signal envelope algorithm can extract useful features from the vibration signal. The effectiveness of the new detection algorithm was verified. The engine fault detection method based on an angle domain signal envelope algorithm provides a new way to detect and diagnose engine incipient faults.