Rule-based Fault Diagnosis of Hall Sensors and Fault-tolerant Control of PMSM

Hall sensor is widely used for estimating rotor phase of permanent magnet synchronous motor(PMSM). And rotor position is an essential parameter of PMSM control algorithm, hence it is very dangerous if Hall senor faults occur. But there is scarcely any research focusing on fault diagnosis and fault-tolerant control of Hall sensor used in PMSM. From this standpoint, the Hall sensor faults which may occur during the PMSM operating are theoretically analyzed. According to the analysis results, the fault diagnosis algorithm of Hall sensor, which is based on three rules, is proposed to classify the fault phenomena accurately. The rotor phase estimation algorithms, based on one or two Hall sensor(s), are initialized to engender the fault-tolerant control algorithm. The fault diagnosis algorithm can detect 60 Hall fault phenomena in total as well as all detections can be fulfilled in 1/138 rotor rotation period. The fault-tolerant control algorithm can achieve a smooth torque production which means the same control effect as normal control mode (with three Hall sensors). Finally, the PMSM bench test verifies the accuracy and rapidity of fault diagnosis and fault-tolerant control strategies. The fault diagnosis algorithm can detect all Hall sensor faults promptly and fault-tolerant control algorithm allows the PMSM to face failure conditions of one or two Hall sensor(s). In addition, the transitions between health-control and fault-tolerant control conditions are smooth without any additional noise and harshness. Proposed algorithms can deal with the Hall sensor faults of PMSM in real applications, and can be provided to realize the fault diagnosis and fault-tolerant control of PMSM.

Temperature fault-tolerant control system of CSTR with coil and jacket heat exchanger based on dual control and fault diagnosis

For the characteristics of the continuous stirred-tank reactor(CSTR) with coil and jacket cooling system,a CSTR temperature dual control solution based on the analysis of the CSTR exothermic reaction control characteristic was proposed for an organic material polymerization production.The control solution has passive fault-tolerant ability for the jacket cooling water cutting off fault and active fault-tolerant potential for the coil cooling water cutting off fault,and it has good control ability,high saving energy and reducing consumption performance.Fault detection and diagnosis and fault-tolerant control strategy are designed for the coil cooling fault to achieve the active fault-tolerant control function.The CSTR temperature dual control,process fault detection and diagnosis and active fault-tolerant control were full integrated into the CSTR temperature fault-tolerant control system,which achieve fault tolerance control of CSTR temperature for any severe malfunction of jacket cooling or coil cooling cutting off,and the security for CSTR exothermic reaction is improved.Finally,the effectiveness of this system was validated by semi-physical simulation experiment.

Fault diagnosis and fault-tolerant control of photovoltaic micro-inverter

An observer-based fault diagnosis method and a fault tolerant control for open-switch fault and current sensor fault are proposed for interleaved flyback converters of a micro-inverter system. First, based on the topology of a grid-connected micro-inverter, a mathematical model of the flyback converters is established. Second, a state observer is applied to estimate the currents online and generate corresponding residuals. The fault is diagnosed by comparing the residuals with the thresholds. Finally, a fault-tolerant control that consists of a fault-tolerant topology for the faulty switch and a simple software redundancy control for the faulty current sensor, is proposed to achieve a fault-tolerant operation. The feasibility and effectiveness of the proposed method has been verified by simulation and experimental results.

Design and Analysis of Fault Diagnosis and Fault-tolerant Control for a Class of MIMO Nonlinear State Systems

This paper presents a fault diagnosis and fault-tolerant control algorithm,which can be used for a class of multi-input multi-output(MIMO)nonlinear state systems.First,a state estimator is proposed,which is able to detect fault occurrence,by using a residual signal.Second,when the state is at an abnormal condition,the fault-tolerant control will be triggered to minimize the impact of the fault occurrence.This fault-tolerant control is designed by using a robust controller(original controller),and an on-line approximator to capture a nonlinear function that indicates the fault occurrence.The detailed analysis is given for the proposed fault accommodation control.

An Equipment Fault-tolerant Control Expert System and its Application

This paper presents an expert system that can automatically monitor, diagnose and fault-tolerant control by combining fault diagnosis with fault-tolerant technology. The features of the structure of this expert system, knowledge acquisition and organization, and the strategies and realized methods of fault-tolerant control are introduced. An applied example is given.

Design and implementation of an expert system for remote fault diagnosis in ship lift

In this paper an expert system for remote fault diagnosis in the ship lift was developed by analysis of the fault tree and combination with VPN. The fault tree was constructed based on the operation condition of the ship lift. The diagnosis model was constructed by hierarchical classification of the fault tree structure, and the inference mechanism was given. Logical structure of the fault diagnosis in the ship lift was proposed. The implementation of the expert system for remote fault diagnosis in the ship lift was discussed, and the expert system developed was realized on the VPN virtual network. The system was applied to the Gaobaozhou ship lift project, and it ran successfully.

Backstepping-based active fault-tolerant control for a class of uncertain SISO nonlinear systems

Active fault-tolerant control is investigated for a class of uncertain SISO nonlinear flight control systems based on the adaptive observer, feedback linearization and backstepping theory.Firstly an adaptive observer is constructed to estimate the fault in the faulty system.A new fault updating law is presented to simplify the assumption conditions of the adaptive observer.The asymptotical stability of the observer and the uniform ultimate boundedness of the fault estimation error are guaranteed by Lyapunov theorem.Then a backstepping-based active fault-tolerant controller is designed for the faulty system.The asymptotical stability of the closed-loop system and uniform ultimate boundedness of the tracking error are proved based on Lyapunov theorem.The effectiveness of the proposed scheme is demonstrated through the numerical simulation of a flight control system.

Robust and Active Fault-tolerant Control for a Class of Nonlinear Uncertain Systems

A novel integrated design strategy for robust fault diagnosis and fault-tolerant control （FTC） of a class of nonlinear uncertain systems is proposed. The uncertainties considered in this paper are more general than those in other existing works, and faults are described in a new formulation. It is proven that the states of a closed-loop system converge asymptotically to zero even if there are uncertainties and faults in a system. Simulation results on a simple pendulum are presented for illustration.

Neural network-based fault diagnosis for spacecraft with single-gimbal control moment gyros

This paper proposes a neural network-based fault diagnosis scheme to address the problem of fault isolation and estimation for the Single-Gimbal Control Moment Gyroscopes(SGCMGs)of spacecraft in a periodic orbit.To this end,a disturbance observer based on neural network is developed for active anti-disturbance,so as to improve the accuracy of fault diagnosis.The periodic disturbance on orbit can be decoupled with fault by resorting to the fitting and memory ability of neural network.Subsequently,the fault diagnosis scheme is established based on the idea of information fusion.The data of spacecraft attitude and gimbals position are combined to implement fault isolation and estimation based on adaptive estimator and neural network.Then,an adaptive sliding mode controller incorporating the disturbance and fault estimation results is designed to achieve active fault-tolerant control.In addition,the paper gives the proof of the stability of the proposed schemes,and the simulation results show that the proposed scheme achieves better diagnosis and control results than compared algorithm.

Fault diagnosis and accommodation with flight control applications

This paper reviews some main results and process concerning with fault diagnosis and accommodation with flight control applications.The fault detection and diagnosis including the quantitative and qualitative methods and the fault-tolerant control including passive and active schemes are introduced,respectively.The control designs and developments of the fault diagnosis and accommodation for continuous-time systems and discrete-time systems,the fault diagnosis and fault-tolerant control for switched systems and interconnected systems as well as the applied flight control research including hypersonic vehicle,spacecraft and helicopter systems are summarised.

Mine-Hoist Active Fault Tolerant Control System and Strategy

Based on fault diagnosis and fault tolerant technologies, the mine-hoist active fault-tolerant control system (MAFCS) is presented with corresponding strategies,, which includes the fault diagnosis module (FDM), the dynamic library (DL) and the fault-tolerant control module (FCM). When a fault is judged from some sensor by FDM, FCM reconfigure the state of MAFCS by calling the parameters from all sub libraries in DL, in order to ensure the reliabil- ity and safety of mine hoist. The simulating result shows that, MAFCS is of certain intelligence, which can adopt the corresponding control strategies according to different fault modes, even when there are quite difference between the real data and the prior fault modes.

A review on fault-tolerant cooperative control of multiple unmanned aerial vehicles

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.

Active fault-tolerant tracking control of a quadrotor with model uncertainties and actuator faults

This paper presents a reliable active fault-tolerant tracking control system(AFTTCS) for actuator faults in a quadrotor unmanned aerial vehicle(QUAV). The proposed AFTTCS is designed based on a well-known model reference adaptive control(MRAC) framework that guarantees the global asymptotic stability of a QUAV system. To mitigate the negative impacts of model uncertainties and enhance system robustness, a radial basis function neural network is incorporated into the MRAC scheme for adaptively identifying the model uncertainties online and modifying the reference model. Meanwhile, actuator dynamics are considered to avoid undesirable performance degradation. Furthermore, a fault detection and diagnosis estimator is constructed to diagnose lossof-control-effectiveness faults in actuators. Based on the fault information, a fault compensation term is added to the control law to compensate for the adverse effects of actuator faults. Simulation results show that the proposed AFTTCS enables the QUAV to track the desired reference commands in the absence/presence of actuator faults with satisfactory performance.

Fault-Tolerant Model Predictive Control of a Fixed-Wing UAV with Actuator Fault Estimation

The vast majority of today's agtering ayateas poas operational constsinta and have multiple inputa and outputa.This classifen them an Mults-Input Multi-Orutput(MIMO)ayn tena.This pape devekops a novel obeerver-hased fault diagnoas schene with the capability d simultaneoua state and actuator fault estimation for Linear Time-In ariant(LTI)MIMO aystenaa,which is then integrated with Model Predictive Control(MPC)method for achie ving fault-tolerant control.The application within this study is chosen to be the longitudinal flight control o a fixad-wing Unmanmed Aerial Vetücle(UAV).The oberver-based method is dom hüned with two MPC schemas to detect and compansate randomly oeeurring actuator faults in real time.The faults are modeled asa Lans Of Efkctiveess(LOE).For the first(dfident)MPCmethod,a simpke remnniguration can be perkormed in the esent of faulta,as it is based on a abaolute Input foemmlation.Howeve,as the seeond(integrd-action)MPC is based on a incamen tal input formulation,rconfiguration is notrequired,sinee this algorithm has&degrc of implicst fault tokeranee.Numerfcal simulationa danstrate the afetivens of the panposed approach for both MPC sebemes.

基于控制系统的燃气轮机故障识别方法

设计了一种燃气轮机故障识别系统,通过在控制系统内部集成专家知识,实现了对燃气轮机运行状态的实时监控和故障预测。目前,燃气轮机的故障检测主要依赖于控制系统的报警以及维护人员的经验和事后分析,这种方法的维护效率存在局限性。为了提高效率,研究提出了一种新的方法,该方法从明确故障识别目标出发,利用数据可视化工具,通过分析不同工况下的历史运行数据,构建参数历史数据集,基于分析结果,训练故障预警模型,依据制定的故障判断与溯源规则,在线部署到控制系统中。经过燃气轮机仿真验证,显示出良好的时效性和准确性,表明其具有在实际生产环境中应用的潜力。

基于故障树分析的火控系统故障诊断专家系统设计

传统的故障诊断方法应用于火控系统故障诊断时,诊断过程较为复杂,对维修人员有着较高的要求;针对这些局限性,论述了故障树分析法与专家系统之间的关系,提出并设计了基于故障树分析的火控系统故障诊断专家系统;在故障树和数据库的基础上建立知识库和推理机,设计系统软件框架和工作流程,实现对火控系统数据的自动采集、自动存储、自动分析和自动诊断。结论表明该系统能够实现对坦克火控系统的实时监控,对于典型故障可及时准确地诊断并给出可选择的解决方案,为部队提供了简单适用的诊断工具,给今后的装备保障工作带来便利。

一种火控系统故障诊断专家系统

针对故障诊断领域的特点 ,建立了一个用于火控系统故障诊断的专家系统。论述了该系统的知识表示、推理机制和体系结构。实现了将故障监测硬件技术和专家系统软件技术有机结合 ,构造了集硬件、软件为一体的火控系统故障诊断专家系统。

智能诊断技术在水电机组振动故障诊断中的应用

简述了智能诊断技术的发展状况,介绍了智能诊断技术中专家系统、模糊控制、神经网络控制等的特点及在水电机组故障诊断中的应用研究成果,并分析了水电机组振动故障智能诊断技术的发展前景。

矿用空压机远程监控预警及故障诊断专家系统

采用先进的千兆以太环网通讯技术,以可编程序控制器PLC和上位机组态软件为开发平台,对现场检测元件检测的空压机各检测参数进行采集、分析和实时反馈,实现空压机的远程监控和实时预警;并综合运用SQL Server数据库系统和CLIPS专家系统工具建立相应的故障诊断规则,完成矿用空压机远程监控预警及故障诊断专家系统的设计,提高空压机运行的安全系数和对故障的分析能力。

面向对象的水电厂智能故障诊断系统

针对中小型水电厂运行过程中故障诊断的需要，以分布式计算机控制系统的结构为基础，提出一种智能数据采集单元和层次式多专家系统协同作业进行故障诊断的方法，并论述了面向对象的智能化故障诊断系统的体系结构和实施技术。实际运行表明，所提出的方法是有效可行的。