Zero-point fault detection of load cells in truck scale based on recursive principal component analysis and comprehensive evaluation method

Measurement ◽  
2020 ◽  
Vol 159 ◽  
pp. 107706
Author(s):  
Haijun Lin ◽  
Huixia Li ◽  
Gengrong Shao ◽  
Yuan Ye ◽  
Yuxiang Yang
2014 ◽  
Vol 1010-1012 ◽  
pp. 321-324 ◽  
Author(s):  
Xian Lin Meng ◽  
Guang Liang Fan ◽  
Xiao Hui Cao ◽  
Jun Guo He ◽  
Jian Hua Qu

The evaluation of surface water quality is a problem which relates to whether the environmental function and value do possess or not in the water. A new comprehensive evaluation method which combines Principal Component Analysis (PCA) and the weighted grey correlation method was presented in this paper. The reduction of indicators and the weakening of the multiple correlation among indicators were considered in Principal Component Analysis. According to different functional areas categories of every section, the weighted grey correlation method could determine the evaluation indicator’s weights, strengthen the effect of concerntrations of indicators and consider each indicator’s impact. The Mudanjiang River downstream sections were used as the research object. Based on the water quality monitoring data of typical monitoring section in 2013, the study on the environmental quality assessment of downstream section in mudanjiang was given in this paper. The efficiency of the evaluation process and the accuracy of the results can be improved.


2021 ◽  
Vol 11 (14) ◽  
pp. 6370
Author(s):  
Elena Quatrini ◽  
Francesco Costantino ◽  
David Mba ◽  
Xiaochuan Li ◽  
Tat-Hean Gan

The water purification process is becoming increasingly important to ensure the continuity and quality of subsequent production processes, and it is particularly relevant in pharmaceutical contexts. However, in this context, the difficulties arising during the monitoring process are manifold. On the one hand, the monitoring process reveals various discontinuities due to different characteristics of the input water. On the other hand, the monitoring process is discontinuous and random itself, thus not guaranteeing continuity of the parameters and hindering a straightforward analysis. Consequently, further research on water purification processes is paramount to identify the most suitable techniques able to guarantee good performance. Against this background, this paper proposes an application of kernel principal component analysis for fault detection in a process with the above-mentioned characteristics. Based on the temporal variability of the process, the paper suggests the use of past and future matrices as input for fault detection as an alternative to the original dataset. In this manner, the temporal correlation between process parameters and machine health is accounted for. The proposed approach confirms the possibility of obtaining very good monitoring results in the analyzed context.


Author(s):  
Hongjuan Yao ◽  
Xiaoqiang Zhao ◽  
Wei Li ◽  
Yongyong Hui

Batch process generally has varying dynamic characteristic that causes low fault detection rate and high false alarm rate, and it is necessary and urgent to monitor batch process. This paper proposes a global enhanced multiple neighborhoods preserving embedding based fault detection strategy for dynamic batch process. Firstly, the angle neighbor is defined and selected to compensate for the insufficient expression for the spatial similarity of samples only by using the distance neighbor, and the time neighbor is introduced to describe the time correlations between samples. These three types of neighbors can fully characterize the similarity of the samples in time and space. Secondly, considering the minimum reconstruction error and the order information of three types of neighbors, an enhanced objective function is constructed to prevent the loss of order information when neighborhood preserving embedding (NPE) calculates the reconstruction weights. Furthermore, the enhanced objective function and a global objective function are organically combined to extract both global and local features, to describe process dynamics and visualize process data in a low-dimensional space. Finally, a monitoring index based on support vector data description is constructed to eliminate adverse effects of non-Gaussian data for monitoring performance. The advantages of the proposed method over principal component analysis, neighborhood preserving embedding, dynamic principal component analysis and time NPE are demonstrated by a numerical example and the penicillin fermentation process simulation.


2019 ◽  
Vol 1 (1) ◽  
Author(s):  
Guangqi Ying ◽  
Yan Ran ◽  
Genbao Zhang ◽  
Yuxin Liu ◽  
Shengyong Zhang

For the traditional multi-process capability construction method based on principal component analysis, the process variables are mainly considered, but not the process capability, which leads to the deviation of the contribution rate of principal component. In response to the question, this paper first clarifies the problem from two aspects: theoretical analysis and example proof. Secondly, aiming at the rationality of principal components degree, an evaluation method for pre-processing data before constructing MPCI using PCA is proposed. The pre-processing of data is mainly to standardize the specification interval of quality characteristics making the principal components degree more reasonable and optimizes the process capability evaluation method. Finally, the effectiveness and feasibility of the method are proved by an application example.


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