To solve the problem of small amount of machining centers in small and medium flexible manufacture systems(FMS), a scheduling mode of single automated guided vehicle(AGV) is adopted to deal with multiple transport req...To solve the problem of small amount of machining centers in small and medium flexible manufacture systems(FMS), a scheduling mode of single automated guided vehicle(AGV) is adopted to deal with multiple transport requests in this paper. Firstly, a workshop scheduling mechanism of AGV is analyzed and a mathematical model is established using Genetic Algorithm. According to several sets of transport priority of AGV, processes of FMS are encoded, and fitness function, selection, crossover, and variation methods are designed. The transport priority which has the least impact on scheduling results is determined based on the simulation analysis of Genetic Algorithm, and the makespan, the longest waiting time, and optimal route of the car are calculated. According to the actual processing situation of the workshop, feasibility of this method is verified successfully to provide an effective solution to the scheduling problem of single AGV.展开更多
This paper discusses a class of interval alignment （IA） scheduling policies, which are particularly effective for the systems that do not have Markovian structure. The numerical results show that IA policies effecti...This paper discusses a class of interval alignment （IA） scheduling policies, which are particularly effective for the systems that do not have Markovian structure. The numerical results show that IA policies effectively smooth part flows, improve performance and decrease average Work-in-Process （WlP） by adding intermediate delays to the system, The boundary of IA policy is proven and the applications of IA policy in the system with multiple stream arrivals have been discussed. With the combination of release policy, it is practical to implement IA to multiple stream arrival system.展开更多
基金Supported by the National Natural Science Foundation of China(No.51765043)
文摘To solve the problem of small amount of machining centers in small and medium flexible manufacture systems(FMS), a scheduling mode of single automated guided vehicle(AGV) is adopted to deal with multiple transport requests in this paper. Firstly, a workshop scheduling mechanism of AGV is analyzed and a mathematical model is established using Genetic Algorithm. According to several sets of transport priority of AGV, processes of FMS are encoded, and fitness function, selection, crossover, and variation methods are designed. The transport priority which has the least impact on scheduling results is determined based on the simulation analysis of Genetic Algorithm, and the makespan, the longest waiting time, and optimal route of the car are calculated. According to the actual processing situation of the workshop, feasibility of this method is verified successfully to provide an effective solution to the scheduling problem of single AGV.
文摘This paper discusses a class of interval alignment （IA） scheduling policies, which are particularly effective for the systems that do not have Markovian structure. The numerical results show that IA policies effectively smooth part flows, improve performance and decrease average Work-in-Process （WlP） by adding intermediate delays to the system, The boundary of IA policy is proven and the applications of IA policy in the system with multiple stream arrivals have been discussed. With the combination of release policy, it is practical to implement IA to multiple stream arrival system.
