Machine learning techniques for fault isolation and sensor placement

Fault isolation and sensor placement are vital for monitoring and diagnosis. A sensor conveys information about a system's state that guides troubleshooting if problems arise. We are using machine learning methods to uncover behavioral patterns over snapshots of system simulations that will aid fault isolation and sensor placement, with an eye towards minimality, fault coverage, and noise tolerance

Comparison of different classification algorithms for fault detection and fault isolation in complex systems

Due to the lack of sufficient results seen in literature, feature extraction and classification methods of hydraulic systems appears to be somewhat challenging. This paper compares the performance of three classifiers (namely linear support vector machine (SVM), distance-weighted k-nearest neighbor (WKNN), and decision tree (DT) using data from optimized and non-optimized sensor set solutions. The algorithms are trained with known data and then tested with unknown data for different scenarios characterizing faults with different degrees of severity. This investigation is based solely on a data-driven approach and relies on data sets that are taken from experiments on the fuel system. The system that is used throughout this study is a typical fuel delivery system consisting of standard components such as a filter, pump, valve, nozzle, pipes, and two tanks. Running representative tests on a fuel system are problematic because of the time, cost, and reproduction constraints involved in capturing any significant degradation. Simulating significant degradation requires running over a considerable period; this cannot be reproduced quickly and is costly

Rapid gravity filtration operational performance assessment and diagnosis for preventative maintenance from on-line data

Rapid gravity filters, the final particulate barrier in many water treatment systems, are typically monitored using on-line turbidity, flow and head loss instrumentation. Current metrics for assessing filtration performance from on-line turbidity data were critically assessed and observed not to effectively and consistently summarise the important properties of a turbidity distribution and the associated water quality risk. In the absence of a consistent risk function for turbidity in treated water, using on-line turbidity as an indicative rather than a quantitative variable appears to be more practical. Best practice suggests that filtered water turbidity should be maintained below 0.1 NTU, at higher turbidity we can be less confident of an effective particle and pathogen barrier. Based on this simple distinction filtration performance has been described in terms of reliability and resilience by characterising the likelihood, frequency and duration of turbidity spikes greater than 0.1 NTU. This view of filtration performance is then used to frame operational diagnosis of unsatisfactory performance in terms of a machine learning classification problem. Through calculation of operationally relevant predictor variables and application of the Classification and Regression Tree (CART) algorithm the conditions associated with the greatest risk of poor filtration performance can be effectively modelled and communicated in operational terms. This provides a method for an evidence based decision support which can be used to efficiently manage individual pathogen barriers in a multi-barrier system

Machine learning and its applications in reliability analysis systems

In this thesis, we are interested in exploring some aspects of Machine Learning (ML) and its application in the Reliability Analysis systems (RAs). We begin by investigating some ML paradigms and their- techniques, go on to discuss the possible applications of ML in improving RAs performance, and lastly give guidelines of the architecture of learning RAs. Our survey of ML covers both levels of Neural Network learning and Symbolic learning. In symbolic process learning, five types of learning and their applications are discussed: rote learning, learning from instruction, learning from analogy, learning from examples, and learning from observation and discovery. The Reliability Analysis systems (RAs) presented in this thesis are mainly designed for maintaining plant safety supported by two functions: risk analysis function, i.e., failure mode effect analysis (FMEA) ; and diagnosis function, i.e., real-time fault location (RTFL). Three approaches have been discussed in creating the RAs. According to the result of our survey, we suggest currently the best design of RAs is to embed model-based RAs, i.e., MORA (as software) in a neural network based computer system (as hardware). However, there are still some improvement which can be made through the applications of Machine Learning. By implanting the 'learning element', the MORA will become learning MORA (La MORA) system, a learning Reliability Analysis system with the power of automatic knowledge acquisition and inconsistency checking, and more. To conclude our thesis, we propose an architecture of La MORA

Self-tuning routine alarm analysis of vibration signals in steam turbine generators

This paper presents a self-tuning framework for knowledge-based diagnosis of routine alarms in steam turbine generators. The techniques provide a novel basis for initialising and updating time series feature extraction parameters used in the automated decision support of vibration events due to operational transients. The data-driven nature of the algorithms allows for machine specific characteristics of individual turbines to be learned and reasoned about. The paper provides a case study illustrating the routine alarm paradigm and the applicability of systems using such techniques

Analysis of the Diagnostic Methods of the Performance Failure of Heating and Air Conditioning Systems

The paper introduces some diagnostic methods for the performance failure of heating and air conditioning, analyzes the principle by an example, gives the application characteristics of different methods and supplies the guide for the application of fault detection and diagnostic technology

An Adaptive Resonance Theory Neural Network (ART NN)-based fault diagnosis system: A Case Study of gas turbine system in Resak Development Platform

The project introduces a case study of a real gas turbine system in Resak Development Platform. There are two main objectives of this project. The first objective is aimed to achieve an online fault diagnosis model using Adaptive Resonance Theorem (ART) as a considered option to avoid potential faults happen during plant system and process. The second objective is focused on a solution to improve the maintenance plan for the gas turbine system to be more economical yet still maintaining its safety level

A two-level structure for advanced space power system automation

The tasks to be carried out during the three-year project period are: (1) performing extensive simulation using existing mathematical models to build a specific knowledge base of the operating characteristics of space power systems; (2) carrying out the necessary basic research on hierarchical control structures, real-time quantitative algorithms, and decision-theoretic procedures; (3) developing a two-level automation scheme for fault detection and diagnosis, maintenance and restoration scheduling, and load management; and (4) testing and demonstration. The outlines of the proposed system structure that served as a master plan for this project, work accomplished, concluding remarks, and ideas for future work are also addressed

Fault Diagnosis & Field Measurement Prediction Techniques for a Gas Metering System

This report discusses on research regarding fault diagnosis system for a process plant. In this project, the process studied is Petronas gas metering system to Kapar Power Plant. There are two parts to this project. The first part is focused on proposing a backup fault diagnosis method for this gas metering system. The second part of the project is to propose suitable field measurement prediction techniques, which could be used in the event of a fault or intermediate condition. In order to achieve the first objective, this report first discusses the potential fault diagnosis methods which can be applied to the metering system. The advantages and disadvantages of each method were evaluated. From evaluation, it was chosen to propose fault diagnosis system using Adaptive Neuro Fuzzy Inference System (ANFIS). In order to carry out fault diagnosis, data is first filtered into fault data and healthy data. The faults filtered in this report include transmitter fault and hang fault for parameters of Temperature, Pressure and Gross Volume. Once healthy data was identified, it was further classified into normal and intermediate categories. This process was done through three different methods, which are the hyperbox model, linear model and ANFIS model. Once these models were analysed, the writer has chosen to proceed with ANFIS model for data classification. Classified data was then grouped into clusters. The second part of the project is focused on proposing suitable field measurement prediction technique using ANFIS that can be used in the event of fault or intermediate conditions. Six different ANFIS models were developed to estimate parameters Temperature, Pressure and Gross Volume during transmitter and hang fault. Five variables such as ANFIS input, data division, number of epoch for training, type of membership function and randomisation of data were varied in order to develop the best model. ANFIS prediction model for Temperature produced satisfactory results of less than 1% error. ANFIS prediction model for Pressure and Gross Volume on the other hand need to be further developed to meet industrial requirements