Nonlinear Three-Tank System Fault Detection and Isolation Using Differential Flatness

TL;DR

This paper presents a novel fault detection and isolation method for hydraulic systems based on differential flatness, demonstrated on a three-tank system with improved robustness through sensitivity analysis.

Contribution

It introduces a flatness-based fault detection and isolation approach, including a new definition of isolability and a sensitivity analysis for enhanced robustness.

Findings

Effective fault detection on a three-tank hydraulic system

Robustness improved via sensitivity analysis

Applicable to sensor and actuator faults

Abstract

Fault detection and isolation on hydraulic systems are very important to ensure safety and avoid disasters. In this paper, a fault detection and isolation method, based on the flatness property of nonlinear systems, is experimentally applied on the three-tank system, which is considered as a popular prototype of hydraulic systems. Specifically, fault indicators, called residues, are generated using flat output measurements, and for the purpose of fault isolation, a definition of the isolability is introduced. This definition allows the characterization of flat outputs that are useful for fault isolation. A sensitivity analysis is proposed in order to improve the robustness of the method. Multiplicative faults are considered on sensors and actuators.