Hankel matrix-based Mahalanobis distance for fault detection robust towards changes in process noise covariance

A Corrector for the Sample Mahalanobis Distance Free from Estimating the Population Eigenvalues of Covariance Matrix

Anomaly detection for IGBTs using Mahalanobis distance

In this study, a Mahalanobis distance (MD)-based anomaly detection approach has been evaluated for non-punch through (NPT) and trench field stop (FS) insulated gate bipolar transistors (IGBTs). The IGBTs were subjected to electrical–thermal stress under a resistive load until their failure. Monitored on-state collector–emitter voltage and collector–emitter currents were used as input parameters...

Estimation of true Mahalanobis distance from eigenvectors of sample covariance matrix

あらまし パターン認識で用いられる,ベイズの定理から導かれる統計的識別関数は,パターンの確率分布が 正しく与えられたときに誤識別率が最小になる.パターンの確率分布は一般に未知であるため,正規分布を仮定 して,その平均ベクトルと共分散行列は学習サンプルからの推定値を用いることが多い.しかし,推定に用いる 学習サンプルが不足すると,推定値が誤差を含み,認識性能が低下することが知られている.平均ベクトルや共 分散行列の固有値の推定誤差についてはよく調査され,認識性能の低下を回避する方法が提案されている.しか し,共分散行列の固有ベクトルの推定誤差については,これまでほとんど考慮されてこなかった.本論文では, 学習サンプルが十分用意できない場合においても高精度な認識を行うことを目的とし,共分散行列の固有ベクト ルに誤差がある場合でも,2 次識別関数の主要部分であるマハラノビス距離を正しく推定...

A Method to Estimate the True Mahalanobis Distance from Eigenvectors of Sample Covariance Matrix

In statistical pattern recognition, the parameters of distributions are usually estimated from training sample vectors. However, estimated parameters contain estimation errors, and the errors cause bad influence on recognition performance when the sample size is not sufficient. Some methods can obtain better estimates of the eigenvalues of the true covariance matrix and can avoid bad influences...

Robust Model- Based Fault Detection and Isolation for V47/660kW Wind Turbine

In this paper, in order to increase the efficiency, to reduce the cost and to prevent the failures of wind turbines, which lead to an extensive break down, a robust fault diagnosis system is proposed for V47/660kW wind turbine operated in Manjil wind farm, Gilan province, Iran. According to the acquired data from Iran wind turbine industry, common faults of the wind turbine such as sensor fault...