Condition Monitoring of Lubricant in Static Mechanisms Using Pulse-Echo Ultrasound Technique

This paper proposes an active pulse-echo ultrasonic testing method to determine the lubricant condition in static mechanical components and assemblies. An ultrasonic inspection system was constructed to produce and receive back, high frequency ultrasonic pulses. Wavelet transform was used to de-noise the acquired signal and extract features from the feedback waveforms. Features data, from different samples, were analyzed and used to develop a fuzzy inference system to define the lubricant condition. Classification system was then examined, using grease samples, with known condition. The results indicated that the novel pulse-echo technique is a suitable method for the inspection of lubricants condition in various engineering systems. (C) 2016 The Authors. Published by Elsevier B.V.