关键词: 流水车间生产调度, 不确定性, 零等待, 免疫算法

Abstract: For solving the scheduling problems of flow shop under uncertainty with zero wait, a fuzzy mathematical model was presented based on the fuzzy programming theory, in which uncertain processing time of products was described by the triangular fuzzy number. Then, the Maximum Membership Function of Mean Value was applied to transform the original non-linear fuzzy scheduling model into single-objective planning model. Furthermore, an immune scheduling algorithm was proposed by making use of concepts and principles borrowed from natural immune system, which can capture the basic elements of the immune system and exhibit some of its main characteristics. With this method, the sequence of products could be expressed by a character encoding and each antibody denotes a feasible schedule. The affinity was used to elucidate the relationships between antibody and antigen, and the degrees of association among antibodies. At the same time, the searching direction was self-adjusted by the density of antibodies. Simulation results demonstrated the effectiveness of the scheduling model and the proposed algorithm.

Key words: flow shop scheduling, uncertainty, zero wait, immune algorithm