Grey target theory based equipment condition monitoring and wear mode recognition

Grey target theory is a newly developed method in grey system theory. Calculating with grey target theory, pattern recognition, mode gradation and optimal mode selection can be performed. Oil samples from one auto press line and one 16V280ZJA diesel engine were analyzed by analytical ferrograph. For every wear particle in every analytical result, the size and quantity were quantified together. And some corresponding series have been established. Grey target theory was applied and a "bull's-eye" was constructed. By calculating the approaching degrees, wear modes have been graded, in conjunction with the running conditions of the press line and the diesel engine for given operation modes. The order of existing wear modes from severe to benign has also been assessed. The results agree with the experts' analysis. This is the first time that grey target theory has been applied in oil monitoring for wear mode recognition. (c) 2005 Elsevier B.V. All rights reserved.