Online fault detection system for proportional hydraulic valves

Abstract

This paper presents the development of a method for condition monitoring and online fault detection on proportional directional valves. The systems that such valves are part of might be sensitive for unexpected maintenance or long duration stops. Consequently, the implementation of a fault detection and monitoring system can reduce maintenance costs and increase safety. The method is based on monitoring both the valve supply current and spool position related to the spool positioning control signal. Therefore, it is applicable for valves with embedded electronics including spool position measurement and internal controller. The supply current and spool position behavior depends on the friction, flow forces, solenoid current, and valve closed loop controller performance. Furthermore, valve static and dynamic characteristics are influenced by the spool size, overlapping and manufacturing tolerances. The effectiveness of the method to monitor and detect faults in valves with different sizes and constructive parameters is shown experimentally using five different proportional valves. The proposed method requires reference parameters characterizing the valve operation without faults. Standard tests are proposed to determine healthy valve parameters. For the method valuation and validation, experimental results with the valve operating under healthy conditions and with induced faults were compared. Faults were added in a way to represent spool locking and increase of friction forces between the spool and sleeve. The obtained results show the capability the method for the detection of faults classified as severe even if the valve controller attempts to compensate the faulty behavior.

Fault Diagnosis Method for Hydraulic Directional Valves Integrating PCA and XGBoost

“…Li et al [22] proposed a fault diagnosis method that involves choosing the fractal characteristic volume of a valve's displacement signal as a criterion to solve the nonlinear problems in the working process of autopilot hydraulic valves. Raduenz et al [23] presented the development of a method for condition monitoring and online fault detection on proportional reversing valves. The effectiveness of the method to monitor and detect faults in valves with different sizes and constructive parameters was shown experimentally using five different proportional valves.…”

Research and Development of Electro-hydraulic Control Valves Oriented to Industry 4.0: A Review

“…This method has been extended by Raduenz et al According to a large number of collected data, the threshold range of the fault diagnosis has been effectively reduced [92,93]. For a specific proportional valve, the relationship between the control signal and the displacement of the valve spool changes in a certain range with the change of the working conditions.…”

Static and dynamic characteristics of proportional directional valve

“…The Friction includes the influence of viscous and Coulomb friction in the model. The Inerter is also included in the subsystem [5]. The spool position is measured by the Motion Sensor.…”

“…This signal can be easily programmed. The proportional directional valve properties can be described by characteristics [1]. Dynamic characteristics describe the ability of the proportional directional valve to respond to rapid changes of the control signal.…”