Research Papers

Model-Based Condition Monitoring of an Electro-Hydraulic Valve

[+] Author and Article Information
Andreas Steinboeck

Postdoctoral Research Assistant
e-mail: andreas.steinboeck@tuwien.ac.at

Wolfgang Kemmetmüller

Assistant Professor
e-mail: kemmetmueller@acin.tuwien.ac.at

Andreas Kugi

e-mail: kugi@acin.tuwien.ac.at
Automation and Control Institute,
Vienna University of Technology,
Gußhausstraße 27-29/376,
Vienna 1040, Austria

1Corresponding author.

Contributed by the Dynamic Systems Division of ASME for publication in the Journal of Dynamic Systems, Measurement, and Control. Manuscript received March 7, 2012; final manuscript received April 19, 2013; published online August 23, 2013. Assoc. Editor: Warren E. Dixon.

J. Dyn. Sys., Meas., Control 135(6), 061010 (Aug 23, 2013) (9 pages) Paper No: DS-12-1077; doi: 10.1115/1.4024800 History: Received March 07, 2012; Revised April 19, 2013

In many hydraulic systems, it is difficult for human operators to detect faults or to monitor the condition of valves. Based on dynamical models of an electro-hydraulic servo valve and a hydraulic positioning unit, we develop a parametric fault detection and condition monitoring system for the valve. Our approach exploits the nexus between the spool position, the geometric orifice area, the flow conditions at wearing control edges, and the velocity of the controlled cylinder. The effective orifice area of each control edge is estimated based on measurement data and described by aggregate wear parameters. Their development is monitored during the service life of the valve, which allows consistent tracking of the condition of the valve. The method is suitable for permanent in situ condition monitoring. Flow measurements are not required. Computer simulations and measurement results from an industrial plant demonstrate the feasibility of the method.

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Davies, A., ed., 1998, Handbook of Condition Monitoring: Techniques and Methodology, Chapman & Hall, London.
Watton, J., 2007, Modelling, Monitoring and Diagnostic Techniques for Fluid Power Systems, Springer, London.
ISO 13372:2004, 2004, “Condition Monitoring and Diagnostics of Machines—Vocabulary,” ISO, Geneva, Switzerland.
ISO 13379:2003, 2003, “Condition Monitoring and Diagnostics of Machines—General Guidelines on Data Interpretation and Diagnostics Techniques,” ISO, Geneva, Switzerland.
ISO 17359:2011, 2011, “Condition Monitoring and Diagnostics of Machines—General Guidelines,” ISO, Geneva, Switzerland.
Feigel, H.-J., 1987, “Nichtlineare Effekte am servoventilgesteuerten Differentialzylinder (Nonlinear effects on a Servovalve-Controlled Cylinder Actuator With Unsymmetrical Piston Areas),” O+P Ölhydraulik und Pneumatik, 31(1), pp. 42–48.
Jelali, M., and Kroll, A., 2003, “Hydraulic Servo-systems: Modelling, Identification and Control,” Advances in Industrial Control, Springer, London.
Kazemi-Moghaddam, A., 1999, “Fehlerfrühidentifikation und -diagnose eines elektrohydraulischen Linearantriebssystems (Error Identification and Diagnosis for an Electro-Hydraulic Linear Actuator System),” Ph.D. thesis, Technische Universität Darmstadt, Germany.
Kreß, R., 2002, “Robuste Fehlerdiagnoseverfahren zur Wartung und Serienabnahme elektrohydraulischer Aktuatoren (Robust Error Diagnosis Methods for Maintenance and Series Inspection of Electro-Hydraulic Actuators),” Ph.D. thesis, Technische Universität Darmstadt, Germany.
Garimella, P., and Yao, B., 2005, “Model Based Fault Detection of an Electro-Hydraulic Cylinder,” Proceedings of the American Control Conference, Vol. 1, pp. 484–489.
Khan, H., Abou, S., and Sepehri, N., 2005, “Nonlinear Observer-Based Fault Detection Technique for Electro-Hydraulic Servo-Positioning Systems,” Mechatronics, 15(9), pp. 1037–1059. [CrossRef]
An, L., and Sepehri, N., 2008, “Leakage Fault Detection in Hydraulic Actuators Subjected to Unknown External Loading,” Int. J. Fluid Power, 9(2), pp. 15–25.
Ming, T., Zhang, Y., and Zhang, X., 2009, “Fault Detection for Electro-Hydraulic Valve-Controlled Single Rod Cylinder Servo System Using Linear Robust Observer,” Proceedings of the 2009 International Conference on Measuring Technology and Mechatronics Automation, Vol. 1, pp. 639–642.
Werlefors, M., and Medvedev, A., 2008, “Observer-Based Leakage Detection in Hydraulic Systems With Position and Velocity Feedback,” Proceedings of the IEEE Multi-Conference on Systems and Control, pp. 948–953.
Merritt, H., 1967, Hydraulic Control Systems, John Wiley & Sons, New York.
Schothorst, G., 1997, “Modelling of Long-Stroke Hydraulic Servo-Systems for Flight Simulator Motion Control and System Design,” Ph.D. thesis, Delft University of Technology, Delft, The Netherlands.
Ferreira, J., Gomes de Almeida, F., and Quintas, M., 2002, “Semi-Empirical Model for a Hydraulic Servo-Solenoid Valve,” Proc. Inst. Mech. Eng., Part I: J. Syst. Control Eng., 216(3), pp. 237–248. [CrossRef]
Weule, H., 1974, “Eine Durchflußgleichung für den laminar-turbulenten Strömungsbereich (A Flow Equation for the Laminar-Turbulent Flow Range),” O+P Ölhydraulik und Pneumatik, 18(1), pp. 57–66.
Wu, D., Burton, R., and Schoenau, G., 2002, “An Empirical Discharge Coefficient Model for Orifice Flow,” Int. J. Fluid Power, 3(3), pp. 13–18.
Ellman, A., 1998, “Leakage Behavior of Four-Way Servovalve,” ASME Fluid Power Systems and Technology Division, International Mechanical Engineering Congress and Exposition, Vol. 5, pp. 163–167.
Eryilmaz, B., and Wilson, B., 2000, “Combining Leakage and Orifice Flows in a Hydraulic Servovalve Model,” ASME J. Dyn. Syst., Meas. Control, 122(3), pp. 576–579. [CrossRef]
Feki, M., and Richard, E., 2005, “Including Leakage Flow in the Servovalve Static Model,” Int. J. Modell. Simul., 25(1), pp. 51–56.
Wu, D., Burton, R., Schoenau, G., and Bitner, D., 2003, “Modelling of Orifice Flow Rate at Very Small Openings,” Int. J. Fluid Power, 4(1), pp. 31–39.
Armstrong-Hélouvry, B., Dupont, P., and Canudas De Wit, C., 1994, “A Survey of Models, Analysis Tools and Compensation Methods for the Control of Machines With Friction,” Automatica, 30(7), pp. 1083–1138. [CrossRef]
Münchhof, M., 2006, “Model-Based Fault Detection for a Hydraulic Servo Axis,” Ph.D. thesis, Technische Universität Darmstadt, Darmstadt, Germany.
Münchhof, M., 2008, “Displacement Sensor Fault Tolerance for Hydraulic Servo Axis,” Proceedings of the 17th IFAC World Congress, pp. 13803–13808.
Münchhof, M., and Isermann, R., 2004, “Zustandsüberwachung für hydraulische Proportionalwegeventile (State Monitoring for Hydraulic Directional Proportional Valves),” Proceedings of 2nd Paderborner Workshop Intelligente mechatronische Systeme, Heinz Nixdorf Institut, pp. 171–180.
Crowther, W., Edge, K., Burrows, C., Atkinson, R., and Woollons, D., 1998, “Fault Diagnosis of a Hydraulic Actuator Circuit Using Neural Networks—An Output Vector Space Classification Approach,” Proc. Inst. Mech. Eng., Part I: J. Syst. Control Eng., 212(1), pp. 57–68. [CrossRef]
Pollmeier, K., Burrows, C., and Edge, K., 2004, “Condition Monitoring of an Electrohydraulic Position Control System Using Artificial Neural Networks,” Proceedings of the ASME International Mechanical Engineering Congress and Exposition, Vol. 11, pp. 137–146.
Rashidy, H., Rezeka, S., Saafan, A., and Awad, T., 2003, “A Hierarchical Neuro-Fuzzy System for Identification of Simultaneous Faults in Hydraulic Servovalves,” Proceedings of the American Control Conference, Vol. 5, pp. 4269–4274.
Savitzky, A., and Golay, M., 1964, “Smoothing and Differentiation of Data by Simplified Least Squares Procedures,” Anal. Chem., 36(8), pp. 1627–1639. [CrossRef]
Press, W., Teukolsky, S., Vetterling, W., and Flannery, B., 2007, Numerical Recipes: The Art of Scientific Computing, 3rd ed., Cambridge University Press, New York.


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Fig. 1

Third stage of a four-way servo valve with underlap (not to scale)

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Fig. 2

Hydraulic positioning unit

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Fig. 3

Condition monitoring algorithm

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Fig. 4

Opening area characteristic (simulated data)

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Fig. 5

Simulated change of opening area characteristic due to wear (distorted, αA(x) constant along dotted lines)

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Fig. 6

Estimated parameters indicating wear of the valve (simulated data), (a) relative change of contraction coefficient, (b) normalized change of underlap, (c) normalized error

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Fig. 7

Measurements from two comparable hydraulic positioning units, (a) cylinder positions, (b) normalized spool displacements, and (c) pressure values at control ports

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Fig. 8

Opening area characteristic of a normal and a faulty valve (measured data)

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Fig. 9

Long-term changes of opening area characteristic (measured data, distorted, αA(x) constant along dotted lines)



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