Profile Process Capability Assessment Based on Curve Similarity Approach Using Chebyshev Distance

Statistical process control asses the quality of product and process by various methods and tools. When the quality of process represented by regression forms, we use an advanced statistical method for calculating the quality of the product. In recent years, most researchers and users consider profile monitoring as a good technique for single -variable or multiple-variable quality control. A profile is a regression relationship that indicates the relevance of response variable and independent variables. Process Capability Indices (PCIs) evaluate the performance of the production line in producing conforming products. In this paper, the process capability and profile monitoring have been evaluated using the similarity-based technique. Curve similarity is a subcategory of pattern recognition or image processing that measures the degree of similarity. It measures the difference of shapes or curves by using distances, dissimilarity function and etc. In this paper distance method in terms of Chebyshev distance have been used in profile monitoring and PCIs of profiles. Curve similarity approach reduces profile monitoring to monitor a random variable and simplify the calculation of process capability indices. Chebyshev distance determines the distance between each sample profile and a target profile. This approach is applied in monitoring and measuring of PCI of second‐ order polynomial profile (SPP) of an automotive engine.

Keywords:

Process Capability Indices , Profile Monitoring , Curve similarity , Chebyshev distance