Research on the Performance Evaluation of Automotive Engine Based on the Theory of Unascertained Measure

Schematic design has a great influence on product structure, technology, cost, performance, its use and maintenance, it is related to the product level and competitiveness, therefore, how to get as much as possible design schemes and through evaluations from which to choose the best one, is the very important phase in mechanical design process. To evaluate the design scheme scientifically, the main way to seek reasonable scheme is to get its definite evaluation target firstly and then make the quantitative evaluation to the design scheme. In this paper, aiming at the multi-solution, relativity, complexity and multi-factor performance index of scheme in the process of designing cars´ motor, the unascertained measure decision-making model was set up. On the basis of the unascertained measure space, evaluation standards were established in accordance with the order of evaluated space, the quantitative evaluation and the quality rank among design schemes were conducted, and the objectivity and accuracy of evaluated results were improved.