Research Of Multi-Parameter In-Situ Monitoring System For Oil In Mechanical Equipment

Mechanical oil is significant for the regular operation of mechanical equipments.More than that, from it, lots of friction and wear information about friction pair can berevealed. Recenly, oil performance monitoring has been the focus of researches.However, there are still some limitations on the technology of oil monitoring, such aslow efficiency, low intelligence, single monitoring parameter and so on. For thisreason, an oil multi-parameter in-situ monitoring system is designed in this work toachieve the in-situ monitoring on the three parameters of oil included density,moisture content and contamination degree. Moreover, this system is proposed to bealarmed automatically when the monitoring value beyond threshold as well as toprovide the technical index for the analysis and evaluation of the oil and condition ofmachinery and devices.First of all, based on a mass of researches, in this work, the method about sensormodule designing for oil in-situ monitoring is utilized. Based on the method, thestructure and the hardware circuit for three monitoring modules are designed.Moreover the experiments of module parameter calibration and verification test aremade by prepared oil samples. The next, adopting the modular method, the hardwarecircuit and software systems of the whole system are designed based onSTM32F103VC ARM controller. Finally, the effects of temperature and flow rate tothe whole system are discussed. The following results were obtained:(1) Three parameters of oil included density, moisture content and contaminationdegree can be utilized as evaluation indexes for oil whole performance. And themonitoring method designed is feasible. It is verified by experiments that thequadratic function relation is included between oil density and vibration frequencyand the linear relation is included between oil moisture content and capacity, oilcontamination level and transmittance.(2) The relation between three oil monitoring modules result and the real value isreflected effectively due to minor fitting error of three modules’ monitoring curve.The hardware and software of the whole oil in-situ monitoring system tested areshowed in the normal running state. The stability and reliability of whole system are showed to satisfy designing demand. Moreover, the designing efficiency and thegenerality of system can be increased by modular method.(3) The oil vibration frequency, capacity and contamination level are influencedwith variation of temperature and flow speed. Thus, the deviation of temperature mustbe reduced by adding temperature control module or temperature compensationmodule and the deviation of temperature must be reduced by keeping flow speedconstant and adding compensation calculation.The design of the oil in-situ monitoring system in this work is proved to monitorvariation of the oil multiple parameters, which will provide valuable reference for theresearch of oil monitoring in the future.