Journal of South China University of Technology (Natural Science Edition) ›› 2014, Vol. 42 ›› Issue (11): 31-39.doi: 10.3969/j.issn.1000-565X.2014.11.006

• Mechanical Engineering • Previous Articles     Next Articles

Sensor Fault Detection and Isolation for an Electro- Hydraulic Servo System Based on Robust Observer

Xu Qiao-ning1 Yu Feng2 Zhou Hua1 Yang Hua-yong1   

  1. 1.State Key Laboratory of Fluid Power Transmission and Control,Zhejiang University,Hangzhou 310027,Zhejiang,China; 2.Jiujiang Branch of 707 Institute of China Shipbuilding Industry Corporation (CSIC),Jiujiang 332007,Jiangxi,China
  • Received:2014-03-10 Revised:2014-07-11 Online:2014-11-25 Published:2014-11-17
  • Contact: 周华(1968-)，男，博士，教授，主要从事水液压技术、电液控制工程等的研究． E-mail:hzhou@sfp.zju.edu.cn
  • About author:徐巧宁(1985-)，女，博士生，主要从事电液伺服系统故障诊断研究．E-mail:10925053@zju．edu．cn
  • Supported by:

    国家自然科学基金资助项目(51221004)

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Abstract:

In the electro- hydraulic servo system,extra sensors are often added for fault detection and isolation (FDI),but the sensor fault can cause a false alarm.The electro- hydraulic servo system itself is a typical nonlinear system and is often subjected to time- varying and unknown disturbances,which brings about great challenges to the sensor FDI.In order to solve these problems,a FDI scheme based on a nonlinear robust observer is proposed.In this scheme,the robust observer is used to handle the system nonlinearity as well as unknown disturbances and a linear matrix inequality method is adopted to facilitate the observer design.For the sensor fault isolation,a batch of robust observers is designed and some logic rules are made.Then,the proposed FDI scheme is verified by simula- tions and experiments,and an adaptive threshold is designed to make decision according to the characteristics of ex- perimental data.Both simulation and experimental results show that the proposed FDI scheme is effective.

Key words: electro- hydraulic servo system, fault detection, fault isolation, robust observer, adaptive threshold