Internal Leakage Fault Detection and Tolerant Control of Single-Rod Hydraulic Actuators

Jianyong Yao,Guichao Yang,Dawei Ma

doi:10.1155/2014/345345

Jianyong Yao, Guichao Yang + Show 1 more

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https://doi.org/10.1155/2014/345345

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Abstract

The integration of internal leakage fault detection and tolerant control for single-rod hydraulic actuators is present in this paper. Fault detection is a potential technique to provide efficient condition monitoring and/or preventive maintenance, and fault tolerant control is a critical method to improve the safety and reliability of hydraulic servo systems. Based on quadratic Lyapunov functions, a performance-oriented fault detection method is proposed, which has a simple structure and is prone to implement in practice. The main feature is that, when a prescribed performance index is satisfied (even a slight fault has occurred), there is no fault alarmed; otherwise (i.e., a severe fault has occurred), the fault is detected and then a fault tolerant controller is activated. The proposed tolerant controller, which is based on the parameter adaptive methodology, is also prone to realize, and the learning mechanism is simple since only the internal leakage is considered in parameter adaptation and thus the persistent exciting (PE) condition is easily satisfied. After the activation of the fault tolerant controller, the control performance is gradually recovered. Simulation results on a hydraulic servo system with both abrupt and incipient internal leakage fault demonstrate the effectiveness of the proposed fault detection and tolerant control method.

Highlights

Hydraulic systems have been used in industry in a wide number of applications, including robotics and manipulators [1], machine tools [2], active suspension systems [3, 4], hydraulic positioning systems [5,6,7,8], and hydraulic load simulators [9,10,11], by virtue of their small size-to-power ratios, high response, high stiffness, and high load capability
Condition monitoring of hydraulic systems is very useful in the early detection of component failure which would lead to better operational safety and economy
The main feature of the scheme is that a tolerance level of the slight fault is given, and the control performance of the hydraulic systems is guaranteed by a normal robust controller in the normal case and/or the presence of the slight fault case

Summary

Introduction

Hydraulic systems have been used in industry in a wide number of applications, including robotics and manipulators [1], machine tools [2], active suspension systems [3, 4], hydraulic positioning systems [5,6,7,8], and hydraulic load simulators [9,10,11], by virtue of their small size-to-power ratios, high response, high stiffness, and high load capability. Condition monitoring of hydraulic systems is very useful in the early detection of component failure which would lead to better operational safety and economy This has led to the increasing trend towards integrating elements of FDD as part of a control system design [15]. In order to develop FDD algorithms for hydraulic systems, a number of different approaches have been proposed in the literature These include methods based on hardware redundancy [16], parameter estimation methods which utilize linearized models [17] and Volterra models [18], robust observer based methods using nonlinear system models [19, 20], and an informative statistical study [21].

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