Model based multiple faults detection and isolation for electro-hydrostatic actuator

2018 ◽  
Author(s):  
Sadiq Amin Khan ◽  
Wu Qiong
Keyword(s):  
Multiple Faults ◽  
Model Based

A hybrid hidden Markov model towards fault detection of rotating components

2016 ◽  
Vol 23 (19) ◽  
pp. 3175-3195 ◽  
Author(s):  
Ayan Sadhu ◽  
Guru Prakash ◽  
Sriram Narasimhan
Keyword(s):  
Fault Detection ◽  
Markov Model ◽  
Hidden Markov Model ◽  
Time Scale ◽  
Hidden Markov ◽  
Energy Operator ◽  
Fault Classification ◽  
Multiple Faults ◽  
Condition Indicators ◽  
Model Based

A robust hybrid hidden Markov model-based fault detection method is proposed to perform multi-state fault classification of rotating components. The approach presented in this paper enhances the performance of the standard hidden Markov model (HMM) for fault detection by performing a series of pre-processing steps. First, the de-noised time-scale signatures are extracted using wavelet packet decomposition of the vibration data. Subsequently, the Teager Kaiser energy operator is employed to demodulate the time-scale components of the raw vibration signatures, following which the condition indicators are calculated. Out of several possible condition indicators, only relevant features are selected using a decision tree. This pre-processing improves the sensitivity of condition indicators under multiple faults. A Gaussian mixing model-based hidden Markov model (HMM) is then employed for fault detection. The proposed hybrid HMM is an improvement over traditional HMM in that it achieves better separation of the feature space leading to more robust state estimation under multiple fault states and measurement noise scenarios. A simulation employing modulated signals and two experimental validation studies are presented to demonstrate the performance of the proposed method.

scholarly journals A New Approach to Multiple Fault Diagnosis: A Combination of Diagnostic Matrices, Graphs, Algebraic and Rule-Based Models. The Case of Two-Layer Models

2008 ◽  
Vol 18 (4) ◽  
pp. 465-476 ◽  
Author(s):  
Antoni Ligęza ◽  
Jan Kościelny
Keyword(s):  
Fault Diagnosis ◽  
Simultaneous Occurrence ◽  
Diagnostic Model ◽  
Rule Based ◽  
New Approach ◽  
Multiple Fault ◽  
Multiple Faults ◽  
Model Based ◽  
Multiple Fault Diagnosis ◽  
System Variables

A New Approach to Multiple Fault Diagnosis: A Combination of Diagnostic Matrices, Graphs, Algebraic and Rule-Based Models. The Case of Two-Layer ModelsThe diagnosis of multiple faults is significantly more difficult than singular fault diagnosis. However, in realistic industrial systems the possibility of simultaneous occurrence of multiple faults must be taken into account. This paper investigates some of the limitations of the diagnostic model based on the simple binary diagnostic matrix in the case of multiple faults. Several possible interpretations of the diagnostic matrix with rule-based systems are provided and analyzed. A proposal of an extension of the basic, single-level model based on diagnostic matrices to a two-level one, founded on causal analysis and incorporating an OR and an AND matrix is put forward. An approach to the diagnosis of multiple faults based on inconsistency analysis is outlined, and a refinement procedure using a qualitative model of dependencies among system variables is sketched out.

Integrated in-Flight Fault Detection and Accommodation: A Model-Based Study

2007 ◽  
Vol 129 (4) ◽  
pp. 962-969 ◽  
Author(s):  
Randal T. Rausch ◽  
Kai F. Goebel ◽  
Neil H. Eklund ◽  
Brent J. Brunell
Keyword(s):  
High Fidelity Simulation ◽  
Multiple Faults ◽  
Safety Critical ◽  
Fault Accommodation ◽  
Model Based ◽  
High Pressure Compressor ◽  
Flight Envelope ◽  
Binary Classifiers ◽  
Millisecond Range ◽  
Integrated Detection

In-flight fault accommodation of safety-critical faults requires rapid detection and remediation. Indeed, for a class of safety-critical faults, detection within a millisecond range is imperative to allow accommodation in time to avert undesired engine behavior. We address these issues with an integrated detection and accommodation scheme. This scheme comprises model-based detection, a bank of binary classifiers, and an accommodation module. The latter biases control signals with pre-defined adjustments to regain operability while staying within established safety limits. The adjustments were developed using evolutionary algorithms to identify optimal biases off-line for multiple faults and points within the flight envelope. These biases are interpolated online for the current flight conditions. High-fidelity simulation results are presented showing accommodation applied to a high-pressure compressor fault on a commercial, high-bypass, twin-spool, turbofan engine throughout the flight envelope.

Integrated In-Flight Fault Detection and Accommodation: A Model-Based Study

2005 ◽  
Author(s):  
Randal T. Rausch ◽  
Kai F. Goebel ◽  
Neil H. Eklund ◽  
Brent J. Brunell
Keyword(s):  
High Fidelity Simulation ◽  
Turbofan Engine ◽  
Multiple Faults ◽  
Safety Critical ◽  
Fault Accommodation ◽  
Model Based ◽  
Flight Envelope ◽  
Binary Classifiers ◽  
Millisecond Range ◽  
Integrated Detection

In-flight fault accommodation of safety-critical faults requires rapid detection and remediation. Indeed, for a class of safety critical faults, detection within a millisecond range is imperative to allow accommodation in time to avert undesired engine behavior. We address these issues with an integrated detection and accommodation scheme. This scheme comprises model-based detection, a bank of binary classifiers, and an accommodation module. The latter biases control signals with pre-defined adjustments to regain operability while staying within established safety limits. The adjustments were developed using evolutionary algorithms to identify optimal biases off-line for multiple faults and points within the flight envelope. These biases are interpolated online for the current flight conditions. High-fidelity simulation results are presented showing accommodation applied to a high-pressure turbine fault on a commercial, high-bypass, twin-spool, turbofan engine throughout the flight envelope.

scholarly journals A Model-based diagnosis method for transient and multiple faults of AOCS thrusters

2016 ◽  
Vol 49 (17) ◽  
pp. 82-87 ◽  
Author(s):  
C. Pittet ◽  
A. Falcoz ◽  
D. Henry
Keyword(s):  
Multiple Faults ◽  
Model Based ◽  
Diagnosis Method

Multiple Faults Model-Based Detection and Localisation in Complex Systems

2011 ◽  
Vol 20 (1) ◽  
pp. 7-31 ◽  
Author(s):  
Imtiez Fliss ◽  
Moncef Tagina
Keyword(s):  
Complex Systems ◽  
Multiple Faults ◽  
Model Based

Residual Autocorrelation in Probabilistic Model-Based Diagnostics

2005 ◽  
Author(s):  
Matthew L. Schwall ◽  
J. Christian Gerdes
Keyword(s):  
Probabilistic Model ◽  
Diagnostic Techniques ◽  
Probabilistic Framework ◽  
Multiple Faults ◽  
Model Based ◽  
Probability Estimates ◽  
The Relationship

The performance of model-based diagnostic techniques depends not only on the quality of the residuals generated using the models, but also on the method used to interpret the residuals. Robust residuals can often be interpreted deterministically, but noisy residuals can benefit from being interpreted probabilistically. A probabilistic framework enables the modeling of uncertainty and the relationship between multiple faults and multiple residuals. However, it is not well-suited for representing residual dynamics, and as a result, residuals must be assumed to not be autocorrelated. Since this condition is rarely met, this paper analyzes it to determine how residuals can be made to be fit the assumption, and the consequences when the assumption is violated. The paper demonstrates that fault probabilities determined using autocorrelated residuals are useful, but lack calibration. Two methods for removing autocorrelation are discussed and both are shown to result in probability estimates that trade refinement for calibration.

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