Instantaneous RUL Prediction of a Two-Stage Force Feedback Electro-hydraulic Servo Valve (EHSV)

In the area of automation in industries, the electro-hydraulic servo valve (EHSV) is one of the most powerful control devices which makes their RUL prediction a very important task in predictive maintenance prospective. In this paper, the mathematical model of the leakage flow, collected through return oil port, is established and with that a database is created by varying input parameters namely working pressure, density and viscosity of hydraulic fluid. Based on this database, the instantaneous RUL is predicted using KNN regression. Although the leakage flow versus working time graph shows non-linear relationship with the actual data but both showed the same lifespan for the particular working condition. A more robust instantaneous RUL prediction model can be created by preparing the database based on actual leakage data rather than using data from mathematical simulations.