基于Teager算子的柴油机活塞-气缸磨损故障特征增强方法

Feature enhancement of diesel engine'piston-cylinder wear-out faults based on teager energy operator

柴油机活塞与气缸磨损情况是判断柴油机技术状态的主要指标,也是柴油机大修送修的主要条件,其监测诊断一直是柴油机维修的重点。由于柴油机结构复杂,工作状态激烈,活塞-气缸磨损故障很难有效监测诊断,尤其是活塞-气缸早期磨损故障,更是监测诊断一直是研究的重点和难点。根据活塞-气缸磨损后在工作中产生冲击的特点,利用Teager算子提取瞬态冲击信号的优势,对柴油机怠速时缸体上部左侧振动信号进行Teager算子增强,通过提取出的Teager算子能量最大值,判断是否存在活塞-气缸磨损故障以及故障的严重程度。通过两种不同型号柴油机、不同故障缸的机体振动实测信号分析表明,该方法简便有效。

The wear status of piston-cylinder is the main index to diagnose the technical status of a Diesel engine, and the main condition for a Diesel engine,s overhaul and repair. Monitoring and diagnosing piston-cylinder faults, especially, early wear fault are a key of a Diesel engine＇ s repair. As a Diesel engine ＇s structure is complicate and its working condition is rude, so diagnosing piston-cylinder faults is difficult. Here, according to the impulse feature of piston-cylinder^ s wear faults, Teager operator with an advantage to extract instantaneous impulse signals was adopted to enhance features of vibration signals sampled from the left-top position of its cylinder when a Diesel engine idling. The maximum value of Teager operator energy extracted was used to diagnose if there existed piston-cylinder faults and their serious level. The Analysis results of actual vibration signals for two different types of Diesel engine and different faulty cylinders showed that the proposed method is simple and effective.