Research On Intelligent Job Shop Scheduling And Its Applications Based On Multi-objective

The job shop planning and scheduling system is the most critical part of the advanced manufacturing technology, which affects the production efficiency and cost of one enterprise directly. A useful algorithm of job shop scheduling can more raise the performance of the enterprise. As well know, it is also a strong NP-hard combinatorial optimization problem from mathematical viewpoint, and is hard to be solved by the normal method. The research on scheduling concentrates upon the aspects of modeling techniques and algorithms, presently various intelligence methods are gradually introduced in the scheduling problem. The targets and environment of job shop in a scheduling model are described firstly. In order to solve a static scheduling problem based on multi-objective, a genetic algorithm based on machining procedures is adopted. The restrictions of the machine tools and the manufacturing process are considered. The simulation of some examples proves that this algorithm is useful. Then study on job shop scheduling problem for large production. According to the characteristics of large-scale discrete production and the planning arrangements required by different branches inside the enterprise, a production management system directed by the production planning is put forward. At the same time, the mathematic model of diesel engines is proposed which can reflect the relation of all kinds of planning, and the whole frame of the scheduling system is constructed. A practical algorithm for job shop which includes the heuristic algorithm combined by the near insertion approach method is presented. The algorithm can deal with the scheduling problem with multiple constraints, and its principal objective is to get the maximum machine utilization and the shortest cycle of production. It can deal with these dynamic events such as an urgent part insertion, equipment failure and the calendar variation. As a result, the prototype of job shop scheduling system which integrates with other manufacturing systems is designed. At last, the dynamic job shop scheduling system (HD-SFC) for large production in enterprise is developed, and the above-mentioned algorithm and model are proven to be effective.