选择一组能够检测并隔离所有故障的故障检测隔离集(FDIS)是动态系统基于模型故障检测与隔离(FDI)的重要步骤,该步骤通常要求FDIS的基数最小,即求解最小故障检测隔离集(MFDIS),MFDIS的求解时间随着问题规模增大呈指数级增长。BILP(Binary...选择一组能够检测并隔离所有故障的故障检测隔离集(FDIS)是动态系统基于模型故障检测与隔离(FDI)的重要步骤,该步骤通常要求FDIS的基数最小,即求解最小故障检测隔离集(MFDIS),MFDIS的求解时间随着问题规模增大呈指数级增长。BILP(Binary integer linear programming)完备方法是现行动态系统中通用和最高效的MFDIS求解方法,但该方法的求解效率有待提高。本文首次提出了基于部分最大可满足性问题(PMS)的MFDIS求解方法。提出极小超定方程集(MSO)的概念,将部分MSO集合用MSO等价集表示,以缩减问题规模。将MFDIS求解问题转化为PMS问题,进而提高求解效率。实验结果表明,本文方法将问题规模平均约简至原来的8.22%;与BILP方法相比,本文方法的求解效率提高了4.18~9.5倍。展开更多
The Weibull distribution has been widely used in reliability fields. A mixed Weibull distribution represents a popu- lation that consists of several Weibull subpopulations. In this paper, a new approach which combines...The Weibull distribution has been widely used in reliability fields. A mixed Weibull distribution represents a popu- lation that consists of several Weibull subpopulations. In this paper, a new approach which combines the least-squares method with Bayes’ theorem, takes advantage of the parameter estimation for single Weibull distribution is developed to estimate the pa- rameters of each subpopulation. The estimates given by this paper also satisfy the maximum likelihood equation. The estimates of the failure rate of the mixed Weibull population are given. An actual test data is computed by using the proposed method. The Kolmogorov-Smirnov goodness-of-fit test turns out that the proposed method yields more accurate result.展开更多
To improve the detection and identification performance of the Statistical Quality Monitoring （SQM） system, a novel quality based Prioritized Sensor-Fault Detection （PSFD） methodology is proposed. Weighted by the ...To improve the detection and identification performance of the Statistical Quality Monitoring （SQM） system, a novel quality based Prioritized Sensor-Fault Detection （PSFD） methodology is proposed. Weighted by the Vp （variable importance in projection） index, which indicates the importance of the sensor variables to the quality variables, the new monitoring statistic, Qv, is developed toensure that the most vital sensor faults be detected successfully. Subsequently, the ratio between the Detectable Minimum Faulty Magnitude （DMFM） of the most important sensor and of the least important sensor is only gpmin/gpmax 〈〈 1. The Structured Residuals are designed according to the Vp index to identify and then isolate them. The theoretical findings are fully supported by simulation studies performed on the Tennessee Eastman process.展开更多
文摘选择一组能够检测并隔离所有故障的故障检测隔离集(FDIS)是动态系统基于模型故障检测与隔离(FDI)的重要步骤,该步骤通常要求FDIS的基数最小,即求解最小故障检测隔离集(MFDIS),MFDIS的求解时间随着问题规模增大呈指数级增长。BILP(Binary integer linear programming)完备方法是现行动态系统中通用和最高效的MFDIS求解方法,但该方法的求解效率有待提高。本文首次提出了基于部分最大可满足性问题(PMS)的MFDIS求解方法。提出极小超定方程集(MSO)的概念,将部分MSO集合用MSO等价集表示,以缩减问题规模。将MFDIS求解问题转化为PMS问题,进而提高求解效率。实验结果表明,本文方法将问题规模平均约简至原来的8.22%;与BILP方法相比,本文方法的求解效率提高了4.18~9.5倍。
文摘The Weibull distribution has been widely used in reliability fields. A mixed Weibull distribution represents a popu- lation that consists of several Weibull subpopulations. In this paper, a new approach which combines the least-squares method with Bayes’ theorem, takes advantage of the parameter estimation for single Weibull distribution is developed to estimate the pa- rameters of each subpopulation. The estimates given by this paper also satisfy the maximum likelihood equation. The estimates of the failure rate of the mixed Weibull population are given. An actual test data is computed by using the proposed method. The Kolmogorov-Smirnov goodness-of-fit test turns out that the proposed method yields more accurate result.
基金Supported by the National Natural Science Foundation of China （20776128） and the Natural Science Foundation of Zhejiang Province （Y 107032）.
文摘To improve the detection and identification performance of the Statistical Quality Monitoring （SQM） system, a novel quality based Prioritized Sensor-Fault Detection （PSFD） methodology is proposed. Weighted by the Vp （variable importance in projection） index, which indicates the importance of the sensor variables to the quality variables, the new monitoring statistic, Qv, is developed toensure that the most vital sensor faults be detected successfully. Subsequently, the ratio between the Detectable Minimum Faulty Magnitude （DMFM） of the most important sensor and of the least important sensor is only gpmin/gpmax 〈〈 1. The Structured Residuals are designed according to the Vp index to identify and then isolate them. The theoretical findings are fully supported by simulation studies performed on the Tennessee Eastman process.
