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Unformatted text preview: sults for selected toleranced feature. Guided by the simulation results and sensitivity analysis, the production plan has been revised as follows. • Select fixture components with locator errors in the range of [-0.005mm, 0.005mm]. • Assign IT grade 6 to processes 5 and 6 in setup 2 and process 10 in setup 4. • Assign IT grade 5 to process 2 in setup 1. The simulation results show that the new plan is capable to produce finish products that satisfy the design tolerance requirements. This proves that the sensitivity analysis can assist tolerance assignment to generate a feasible assignment plan effectively. 5. TOLERANCE ASSIGNMENT BASED ON GENETIC ALGORITHM The sensitivity analysis based assignment can generate a feasible tolerance assignment plan. However, it may not be optimal since the cost is not considered. In this paper, genetic algorithm is adopted to for tolerance-cost optimization. Suppose there are n features, q parts, and r machines are involved in a production plan, the cost ( C ) is formulated as function of assigned tolerance IT grades ( ITi , i = 1,2,..., n ) and other known constants such as parameters of features...
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- Spring '10
- The Land