Research on fuzzy control charts for fuzzy multilevel quality characteristics

Fuzzy control charts are proposed to solve the problem that traditional cannot be applied fuzzy quality characteristics. First, characteristics converted representative statistics, which mode transformation, level midrange transformation and median transformation. Control designed based on Poisson distribution. Second, effects of different statistics analysed. Direct Charts avoid some information omission when translating into statistics. The area ratio falls within limits is used conclude whether process relative out or in control. performance analysed by MATLAB simulation. Finally, an example energy metre assembly given prove method.