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针对网络化控制系统中在有限频扰动和噪声下的传感器故障检测问题,构建一种新型的观测器结构:动态观测器.利用动态观测器零点可配置这一新特性,提出零点和极点联合优化配置的故障检测方法.所提出的动态观测器是在传统比例积分观测器的基础上扩展而成,更具一般性,具有零点可配置的特点,能够克服传统观测器零点是固定的限制.将动态观测器的零点配置到有限频率测量扰动信号和网络传输延时等外部扰动的特征频谱处,利用零点的特性更好地衰减扰动对残差的影响.给出观测器故障检测的综合性能指标,结合$H_2/H_\infty$优化方法优化动态观测器极点.最后以网络化两轮自平衡机器人的模型为例,比较动态观测器、比例积分观测器、比例观测器的故障检测效果.仿真结果验证了所提动态观测器故障检测方法的优势和有效性. 相似文献
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研究故障观测器优化设计,针对一类非线性动态系统,在考虑系统的输入输出包含外部扰动及建模误差等不确定性项[1]的情况下,为了提高所设计观测器对系统数学模型的在线跟踪能力从而进一步提高故障诊断的鲁棒性减少系统的误报警率,提出了基于模糊神经网络的诊断方法。利用神经网络以及模糊系统对非线性函数的无限逼近能力,设计了基于T-S模糊模型[2]的神经网络自适应观测器来拟合系统的非线性模型和系统的非线性故障特性。由Lyapunov稳定性方法获得调整观测器权重的规律。对所用改进方法的收敛性进行了证明,并通过仿真实例说明了诊断方法的有效性和使用性。 相似文献
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工程实践中常见的带间隙的三明治系统的准确故障预报具有重要的现实意义,为此,本文构建了一种新的动态鲁棒观测器对其进行故障预报.首先,通过将非光滑项转化为干扰项的方法,将间隙非光滑三明治系统转化为可用动态鲁棒观测器设计方法设计的系统.其次,采用零点配置和最小化基准区间观测器的范数(H_∞,F/H_,F)指标的方法确定动态鲁棒观测器的增益矩阵.最后,通过仿真,分别比较了基于非光滑鲁棒观测器和基于传统观测器的故障预报效果,比较结果表明:鲁棒观测器能够及时地准确预报传统观测器无法预报的故障,且有效减少了故障的漏报和错报现象. 相似文献
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针对航空发动机传感器故障诊断中各种方法的优势和劣势,选择滑模观测器和神经网络这两种故障诊断方法分别对航空发动机转速传感器进行故障诊断研究,采用实验室搭建的发动机实验台DGEN380的实验数据,选择对航空发动机控制系统影响较大的偏置故障、漂移故障、脉冲故障、周期性干扰故障这四类传感器故障进行诊断。研究结果表明,滑模观测器和IPSO-BP神经网络都能实现航空发动机传感器的故障诊断;滑模观测器方法可以诊断出偏置故障、脉冲故障和周期性干扰故障,但不能诊断出传感器发生的漂移故障;IPSO-BP神经网络方法可以诊断出偏置故障、漂移故障、脉冲故障和周期性干扰故障。因此,滑模观测器在故障诊断中可能会出现漏诊的现象,IPSO-BP神经网络相对滑模观测器而言不会出现漏诊的现象。 相似文献
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This paper proposes two methods for detecting and reconstructing sensor faults using sliding mode observers. In both methods, fictitious systems are introduced in which the original sensor fault appears as an actuator fault. The original sensor faults are then reconstructed using a ‘secondary’ sliding mode observer. For both methods, there are certain conditions which must be satisfied for successful fault detection and reconstruction. The methods are demonstrated using a chemical process example. 相似文献
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This paper proposes an approach for the joint state and fault estimation for a class of uncertain nonlinear systems with simultaneous unknown input and actuator faults. This is achieved by designing an unknown input observer combined with a set-membership estimation in the presence of disturbances and measurement noise. The observer is designed using quadratic boundedness approach that is used to overbound the estimation error. Sufficient conditions for the existence and stability of the proposed state and actuator fault estimator are expressed in the form of linear matrix inequalities (LMIs). Simulation results for a quadruple-tank system show the effectiveness of the proposed approach. 相似文献
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In this paper, problems related to the integrated design of observer based fault detection systems are addressed. In the context of norm based residual evaluation, a trade-off between false alarm rate (FAR) and fault detection rate (FDR) is first formulated. Aiming at minimizing FAR under given FDR, an approach is then presented for the design of observer based fault detection systems. For this purpose, the well-established factorization technique is applied. Finally, study is devoted to the comparison between the existing methods and the proposed one. 相似文献
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Current sensor is one of the key elements in the control system of induction motor.Whether the accurate measurement of variables reflecting motor operation status can be made will directly affect the control effect on motor system and therefore the timely,accurate detection of sensor fault is necessary.This paper brings forward an observerbased method of residual generation and fault detection on the basis of the mathematical model of the induction motor.As whether or not the nonlinear part satisfies the Lipschitz conditions does not limit the observer design,the application of such an observer is expanded.Meanwhile,the contradiction between robust error and fault sensitivity is also settled.The correctness and effectiveness of such method are verified by experimental testing on the simulated fault which also casts light on engineering practice. 相似文献
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针对航空发动机的故障,设计了基于观测器的鲁棒故障诊断器。介绍了故障诊断中残差生成的一般形式和干扰解耦的基本原理。针对建模中存在的模型不确定性问题,在假定干扰分布已知的前提下,设计了鲁棒残差生成器,实现了残差对干扰解耦的目标,最后仿真模拟了燃油计量活门和尾喷管作动筒故障的情形。仿真结果表明,所设计的鲁棒残差生成器产生的残差具有对干扰低敏感而对故障高敏感的特性,实现了残差对干扰解耦的目标。 相似文献
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This paper presents a novel approach to detect and diagnose faults in the dynamic part of a class of stochastic systems . the Such a group of systems are subjected to a set of crisp inputs but the outputs considered are the measurable probability density functions (PDFs) of the system output, rather than the system output alone. A new approximation model is developed for the output probability density functions so that the dynamic part of the system is decoupled from the output probability density functions. A nonlinear adaptive observer is constructed to detect and diagnose the fault in the dynamic part of the system. Conver-gency analysis is performed for the error dynamics raised from the fault detection and diagnosis phase and an applicability study on the detection and diagnosis of the unexpected changes in the 2D grammage distributions in a paper forming process is included. 相似文献
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Ensuring safety and reliability is a critical objective of advanced Battery Management Systems (BMSs) for Li-ion batteries. In order to achieve this objective, advanced BMS must implement diagnostic algorithms that are capable of diagnosing several battery faults. One set of such critical faults in Li-ion batteries are thermal faults which can be potentially catastrophic. In this paper, a diagnostic algorithm is presented that diagnoses thermal faults in Lithium-ion batteries. The algorithm is based on a two-state thermal model describing the dynamics of the surface and the core temperature of a battery cell. The residual signals for fault detection are generated by nonlinear observers with measured surface temperature and a reconstructed core temperature feedback. Furthermore, an adaptive threshold generator is designed to suppress the effect of modelling uncertainties. The residuals are then compared with these adaptive thresholds to evaluate the occurrence of faults. Simulation and experimental studies are presented to illustrate the effectiveness of the proposed scheme. 相似文献
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基于RBF神经网络观测器飞控系统故障诊断 总被引:4,自引:3,他引:1
为了解决非线性系统采用解析方法进行故障诊断困难的问题,利用神经网络可逼近任意连续有界非线性函数的能力,提出了一种基于RBF神经网络观测器的故障检测与诊断方法,并详细论述了该故障诊断方法的构造原理。以含有非线性项的飞行控制系统的作动器模型为例,仅作动器的输入输出可测量,通过构造RBF神经网络观测器来拟合作动器系统模型,逼近其在正常情况下的输出。最后在飞控系统的闭环控制环境下,对作动器的三种典型故障进行了计算机仿真诊断,结果表明故障诊断方法是有效的。 相似文献