David Henry

Robust fault diagnosis in uncertain linear parameter-varying systems

The purpose of this paper is to develop a new model-based approach for solving FDI (fault detection and isolation) problems in linear parameter-varying plants. The core element of the approach is that the model describing the monitored plant as well as the internal and external perturbations, results in an uncertain linear parameter time-varying model. To solve the problem, a new scheme based on the concept of linear parameter varying (LPV) filters is considered. The proposed method results in designing a LPV fault estimator. The FDI performances are formulated using the notion of quadratic H/sub /spl infin// performance. It is shown that the design problem reduces to solving a system of linear matrix inequalities (LMI). Experimental results performed on the secondary circuit of a French nuclear power plant demonstrate the efficiency of the proposed method.

A LPV approach for early fault detection in aircraft control surfaces servo-loops

Abstract The work presented in this paper is undertaken within the European FP7 funded ADDSAFE * project. The goal is to propose new fault diagnosis techniques that could significantly help developing environmentally-friendlier aircraft, by optimizing structural load design objectives. In this paper, a Linear Parameter Varying (LPV) model-based fault detection scheme is proposed for robust and early detection of faults in aircraft control surfaces servo-loop. The proposed methodology is based on the H ∞ / H _ LPV technique proposed in (Henry, 2012), for LPV systems modeled in a linear fractional representation (LFR) fashion. Simulation results using a “high-fidelity” simulator provided by AIRBUS, are presented to demonstrate the potential of the proposed technique.

Supervisory Fault Tolerant Control Scheme based on Bumpless scheme and Dwell-time Conditions

Abstract The paper deals with the design of an active Fault Tolerant Control (FTC) strategy based on supervisory control approach for Linear Time Invariant (LTI), disturbed and uncertain systems. From a bank of pre-defined Luenberger observers, the observer that yields the smallest observation error determines the present operating mode that is used by a supervisory algorithm to select the corresponding controller. The cases of intermittent and abrupt faults are covered. A key feature of the proposed approach is the establishment of a set of conditions providing transient management and improved value of dwell-time for fault tolerant controllers possessing an integral action or unstable poles. The efficiency of the approach is demonstrated on the HiMAT benchmark (Hou et al., 2010). Copyright

Enhanced distinguishability in Supervisory Fault Tolerant Control

This paper deals with the design of an estimator-based supervisory Fault Tolerant Control (FTC) scheme for Linear Time Invariant (LTI) systems. A formal stability proof based on dwell-time conditions is established in case where the state of the detection filter does not correspond to the plant state, as in classical (Luenberger) observer-based approaches. In this context, fault isolability could be improved leading to an enhanced distinguishability between all possible operating modes. The efficiency of the proposed technique is illustrated on a numerical example.