Fault detection and diagnosis(FDD)approaches comprise three main pillars:model-based,knowledge-based,and data-driven strategies.Data-driven approaches prioritise operational data and do not necessitate in-depth unders...Fault detection and diagnosis(FDD)approaches comprise three main pillars:model-based,knowledge-based,and data-driven strategies.Data-driven approaches prioritise operational data and do not necessitate in-depth understanding of the system’s background;yet,significant amounts of data is required,which often poses challenges to researchers.Since simulated data is inexpensive and can run numerous faults types with varying severities and time periods,it has been used in data-driven FDD analysis.However,the majority of FDD approaches are implemented at the system level of buildings.However,most buildings have numerous systems with distinct features.Furthermore,using individualised system-level analysis makes it difficult to see system-to-system relationships.Currently,there is a significant underrepresentation of research that investigate the applications of FDD models under whole-building scenarios,so as to identify a wider range of energy consumption related faults in buildings.Furthermore,since data-driven approaches significantly depend on the quantities of training data,it becomes challenging to diagnose faults that have limited features.As a result,this study diagnoses numerous building systems faults,including single and simultaneous faults with limited features.This is implemented within the context of the whole-building energy performance of religious buildings in hot climatic areas,employing data-driven FDD methodologies.Various multi-class classification approaches were investigated to classify both the normal condition and faulty classes.Furthermore,feature extraction methodologies were compared to quantify their potential for improving the diagnosis.In addition to the classification evaluation metrics,one-way ANOVA and Tukey-Kramer tests were implemented to examine the significance of the reported performance differences.RF classifier obtained highest classification accuracy during validation and testing with about 90%,indicating a promising performance in whole-building faults analysis.The adoption of feature extraction techniques did not improve classification performance,thereby emphasising that some classifiers may perform better with high-dimensional datasets.展开更多
Recent studies show that artificial intelligence(AI),such as machine learning and deep learning,models can be adopted and have advantages in fault detection and diagnosis for building energy systems.This paper aims to...Recent studies show that artificial intelligence(AI),such as machine learning and deep learning,models can be adopted and have advantages in fault detection and diagnosis for building energy systems.This paper aims to conduct a comprehensive and systematic literature review on fault detection and diagnosis(FDD)methods for heating,ventilation,and air conditioning(HVAC)systems.This review covers the period from 2013 to 2023 to identify and analyze the existing research in this field.Our work concentrates explicitly on synthesizing AI-based FDD techniques,particularly summarizing these methods and offering a comprehensive classification.First,we discuss the challenges while developing FDD methods for HVAC systems.Next,we classify AI-based FDD methods into three categories:those based on traditional machine learning,deep learning,and hybrid AI models.Additionally,we also examine physical model-based methods to compare them with AI-based methods.The analysis concludes that AI-based HVAC FDD,despite its higher accuracy and reduced reliance on expert knowledge,has garnered considerable research interest compared to physics-based methods.However,it still encounters difficulties in dynamic and time-varying environments and achieving FDD resolution.Addressing these challenges is essential to facilitate the widespread adoption of AI-based FDD in HVAC.展开更多
Buildings worldwide account for nearly 40%of global energy consumption.The biggest energy consumer in buildings is the heating,ventilation and air conditioning(HVAC)systems.In HVAC systems,chillers account for a major...Buildings worldwide account for nearly 40%of global energy consumption.The biggest energy consumer in buildings is the heating,ventilation and air conditioning(HVAC)systems.In HVAC systems,chillers account for a major portion of the energy consumption.Maintaining chillers in good conditions through early fault detection and diagnosis is thus a critical issue.In this paper,the fault detection and diagnosis for an air-cooled chiller with air coming from outside in variable flow rates is studied.The problem is difficult since the air-cooled chiller is operating under major uncertainties including the cooling load,and the air temperature and flow rate.A potential method to overcome the difficulty caused by the uncertainties is to perform fault detection and diagnosis based on a gray-box model with parameters regarded as constants.The method is developed and verified by us in another paper for a water-cooled chiller with the uncertainty of cooling load.The verification used a Kalman filter to predict parameters of a gray-box model and statistical process control(SPC)for measuring and analyzing their variations for fault detection and diagnosis.The gray-box model in the method,however,requires that the air temperature and flow rate be nearly constant.By introducing two new parameters and deleting data points with low air flow rate,the requirement can be satisfied and the method can then be applicable for an air-cooled chiller.The simulation results show that the method with the revised model and some data points dropped improved the fault detection and diagnosis(FDD)performance greatly.It can detect both sudden and gradual air-cooled chiller capacity degradation and sensor faults as well as their recoveries.展开更多
This paper presents the recent developments in Fault-Tolerant Cooperative Control(FTCC)of multiple unmanned aerial vehicles(multi-UAVs).To facilitate the analyses of FTCC methods for multi-UAVs.the formation control s...This paper presents the recent developments in Fault-Tolerant Cooperative Control(FTCC)of multiple unmanned aerial vehicles(multi-UAVs).To facilitate the analyses of FTCC methods for multi-UAVs.the formation control strategies under fault-free flight conditions of multi-UAVs are first summarized and analyzed,including the leader-following,behavior-based,virtual structure,collision avoidance,algebraic graph-based,and close formation control methods,which are viewed as the cooperative control methods for multi-UAVs at the pre-fault stage.Then,by considering the various faults encountered by the multi-UAVs,the state-of-the-art developments on individual,leader-following,and distributed FTCC schemes for multi-UAVs are reviewed in detail.Finally,conclusions and challenging issues towards future developments are presented.展开更多
文摘Fault detection and diagnosis(FDD)approaches comprise three main pillars:model-based,knowledge-based,and data-driven strategies.Data-driven approaches prioritise operational data and do not necessitate in-depth understanding of the system’s background;yet,significant amounts of data is required,which often poses challenges to researchers.Since simulated data is inexpensive and can run numerous faults types with varying severities and time periods,it has been used in data-driven FDD analysis.However,the majority of FDD approaches are implemented at the system level of buildings.However,most buildings have numerous systems with distinct features.Furthermore,using individualised system-level analysis makes it difficult to see system-to-system relationships.Currently,there is a significant underrepresentation of research that investigate the applications of FDD models under whole-building scenarios,so as to identify a wider range of energy consumption related faults in buildings.Furthermore,since data-driven approaches significantly depend on the quantities of training data,it becomes challenging to diagnose faults that have limited features.As a result,this study diagnoses numerous building systems faults,including single and simultaneous faults with limited features.This is implemented within the context of the whole-building energy performance of religious buildings in hot climatic areas,employing data-driven FDD methodologies.Various multi-class classification approaches were investigated to classify both the normal condition and faulty classes.Furthermore,feature extraction methodologies were compared to quantify their potential for improving the diagnosis.In addition to the classification evaluation metrics,one-way ANOVA and Tukey-Kramer tests were implemented to examine the significance of the reported performance differences.RF classifier obtained highest classification accuracy during validation and testing with about 90%,indicating a promising performance in whole-building faults analysis.The adoption of feature extraction techniques did not improve classification performance,thereby emphasising that some classifiers may perform better with high-dimensional datasets.
文摘Recent studies show that artificial intelligence(AI),such as machine learning and deep learning,models can be adopted and have advantages in fault detection and diagnosis for building energy systems.This paper aims to conduct a comprehensive and systematic literature review on fault detection and diagnosis(FDD)methods for heating,ventilation,and air conditioning(HVAC)systems.This review covers the period from 2013 to 2023 to identify and analyze the existing research in this field.Our work concentrates explicitly on synthesizing AI-based FDD techniques,particularly summarizing these methods and offering a comprehensive classification.First,we discuss the challenges while developing FDD methods for HVAC systems.Next,we classify AI-based FDD methods into three categories:those based on traditional machine learning,deep learning,and hybrid AI models.Additionally,we also examine physical model-based methods to compare them with AI-based methods.The analysis concludes that AI-based HVAC FDD,despite its higher accuracy and reduced reliance on expert knowledge,has garnered considerable research interest compared to physics-based methods.However,it still encounters difficulties in dynamic and time-varying environments and achieving FDD resolution.Addressing these challenges is essential to facilitate the widespread adoption of AI-based FDD in HVAC.
文摘Buildings worldwide account for nearly 40%of global energy consumption.The biggest energy consumer in buildings is the heating,ventilation and air conditioning(HVAC)systems.In HVAC systems,chillers account for a major portion of the energy consumption.Maintaining chillers in good conditions through early fault detection and diagnosis is thus a critical issue.In this paper,the fault detection and diagnosis for an air-cooled chiller with air coming from outside in variable flow rates is studied.The problem is difficult since the air-cooled chiller is operating under major uncertainties including the cooling load,and the air temperature and flow rate.A potential method to overcome the difficulty caused by the uncertainties is to perform fault detection and diagnosis based on a gray-box model with parameters regarded as constants.The method is developed and verified by us in another paper for a water-cooled chiller with the uncertainty of cooling load.The verification used a Kalman filter to predict parameters of a gray-box model and statistical process control(SPC)for measuring and analyzing their variations for fault detection and diagnosis.The gray-box model in the method,however,requires that the air temperature and flow rate be nearly constant.By introducing two new parameters and deleting data points with low air flow rate,the requirement can be satisfied and the method can then be applicable for an air-cooled chiller.The simulation results show that the method with the revised model and some data points dropped improved the fault detection and diagnosis(FDD)performance greatly.It can detect both sudden and gradual air-cooled chiller capacity degradation and sensor faults as well as their recoveries.
基金supported in part by National Natural Science Foundation of China(Nos.61833013,62003162,62020106003,61873055)Natural Science Foundation of Jiangsu Province of China(No.BK20200416)+4 种基金China Postdoctoral Science Foundation(Nos.2020TQ0151,2020M681590)State Key Laboratory of Synthetical Automation for Process Industries,Northeastern University,Shenyang,China(No.2019-KF-23-05)111 ProjectChina(No.B20007)Natural Sciences and Engineering Research Council of Canada.
文摘This paper presents the recent developments in Fault-Tolerant Cooperative Control(FTCC)of multiple unmanned aerial vehicles(multi-UAVs).To facilitate the analyses of FTCC methods for multi-UAVs.the formation control strategies under fault-free flight conditions of multi-UAVs are first summarized and analyzed,including the leader-following,behavior-based,virtual structure,collision avoidance,algebraic graph-based,and close formation control methods,which are viewed as the cooperative control methods for multi-UAVs at the pre-fault stage.Then,by considering the various faults encountered by the multi-UAVs,the state-of-the-art developments on individual,leader-following,and distributed FTCC schemes for multi-UAVs are reviewed in detail.Finally,conclusions and challenging issues towards future developments are presented.
