Research Scheduling Problem And Algorithm Of Job-shop Robotic Manufacturing Eell

With global market competition intensified, customer demands transform to personalization and diversification. Enterprises increasingly concern on how to design a reasonable schedule scheme to shorten production cycle and reduce work-in-process inventory and deliver just-in-time, etc. Robotic manufacturing cell scheduling problem (RMCSP) is an extension of classic job-shop scheduling problem, and it is also one of the most difficult combinatorial optimization problems. RMCSP contains two sub-problems:the scheduling of job operations on machine and the scheduling of robotic transportation operations. The way to design efficient chromosome encoding scheme for RMCSP is very important when utilizing evolutionary algorithms to solve the scheduling problems. To improve the quality of the initial population, a initialization method based on job operations scheduling is proposed. This paper mainly includes the following aspects:(1)From the perspective of the cell characteristic, the constraints of the scheduling, The job-shop robotic manufacturing cell has been considerable introduced and analyzed.(2)The mathematical optimization and disjunctive graph model are established according the characteristic of job-shop RMCSP with transportation constraints and extra constraints including but not limited to input/output buffer with limited capacity in front of machine. The optimization is to minimize the maximum completion time. A Branch&Bound (B&B) method is promoted to provide solutions satisfying all system constraints. Numerical experiments are studied and the algorithm is verified by the benchmark.(3) Many studies show that single optimization algorithm is much difficult to solve complex scheduling problem, while the improved optimization algorithm or hybrid of some optimization algorithms could provide more powerful search capability. Based on improved genetic algorithm, a local search algorithm is proposed to solve for Solving Job-Shop Scheduling Problem with Several Robots. The characteristic of job-shop robotic manufacturing cell with several transport robots is analyzed from the perspective of the quality of robot. To improve the quality of the initial population, heuristic initialization method based on3vectors scheduling combining dispatching rules is proposed. Then, a mathematical optimization model and an improved disjunctive graph model are established by altering the job-shop robotic manufacturing cell with one robot. Neighborhood structure is constructed based on the critical path. Different neighborhood moving or changing for the first, inside and last operations of the operation block is used respectively. Experimental results show that the algorithm is effective.(4)A scheduling prototype system for RMCSP is developed by combining the research team and actual situation of enterprise in Guangdong province. The paper makes the prospect for further of Robotic manufacturing cell scheduling problem.