Deadlock must be avoided in a manufacturing system. In this paper, an efficient algorithm for finding an optimal deadlock-free schedules in a manufacturing system with very limited buffer is presented. This algorithm is based on the effective genetic algorithm (GA) search method, and a formal Petri net structure is introduced to detect the token player assuring deadlock-free. In order to make the scheduling strategy generated by GA meet the required constraint of deadlock-free, some results of the structure analysis of Petri net are involved as a criterion to select deadlock-free schedule from the population generated by GA. The effectiveness and efficiency of the proposed approach is illustrated by using an example.
A two-phase approach is proposed to deal with the integration problem in theloop layout. Tabu search is applied to cell construction in phase 1 to minimize the inter-cell flow,and the heuristic for layout design is used as phase 2 to optimize the sum of intra-cell andinter-cell transportation cost. The final computational results demonstrate the validation of thetwo-phase approach.
This paper proposes a Genetic Programming-Based Modeling (GPM) algorithm on chaotic time series. GP is used here to search for appropriate model structures in function space, and the Particle Swarm Optimization (PSO) algorithm is used for Nonlinear Parameter Estimation (NPE) of dynamic model structures. In addition, GPM integrates the results of Nonlinear Time Series Analysis (NTSA) to adjust the parameters and takes them as the criteria of established models. Experiments showed the effectiveness of such improvements on chaotic time series modeling.
An efficient algorithm for finding an optimal deadlock-free schedule in amanufacturing system with very limited buffer is presented. This algorithm is based on the effectivegenetic algorithm (GA) search method, and a formal Petri net structure is introduced to detect thetoken player assuring deadlock-free. In order to make the scheduling strategy generated by GA meetthe required constraint of deadlock-free, Petri net is involved to make the implementation of thejob scheduling in an FMS deadlock-free. The effectiveness and efficiency of the proposed approach isillustrated by using an example.
Xu Gang Wu ZhimingSchool of Automation,Shanghai Jiaotong University,Shanghai 200030, China
