Study On Modeling And Scheduling Optimization Algorithm Of CNC Resources Grid

Sharing CNC resources under the network environment is an effective way to solve national CNC resources insufficiency,distribution disproportion,improve the overall utilization of resources and reduce the cost of enterprise groups.However,the current sharing format which almost bases on scheduling mode of "FIFO" and service model of "one task-to-many resources" that is failure to schedule and optimize jobs appropriately,and also fail to integrate tasks and resources simultaneously reduces the efficiency of network sharing on some extent.In recent years,the development of Grid technology provides the possibility to "multi-task-to-multi-resource" model. However,current study on Grid scheduling optimization is based on the unique certain processing route and does not consider complicated associated constraints containing position constraint,parallel processes constraint and so on.By analyzing the complicated associated constraints and property description,this study establishes optimal model from the point of "Constraint Satisfaction Problem",and schedules and optimize then CNC resource nodes and tasks under the grid environment,its main research contents are as follows three aspects:(1) Study of CNC resources Grid Scheduling ProblemComparing with general problem of scheduling,this paper analyzes the differences and difficulties of CNC resource grid scheduling problem under then "multi-task-to-multi-resource" pattern and the complicated associated constraints, brings forward to solve problem from the point of CSP and study the characteristics of the task,operations and NC resources node.(2) Study CNC resource grid scheduling algorithm based on Constraint SatisfactionThe optimization model of CNC resource grid scheduling isestablished from the perspective of CSP,and the Grid Scheduling Algorithm is studied basing on Constraint Satisfaction,whose basic idea is that based on the framework of Tree Search,Compatible Technology is used to reduce the domain of the variables,and with the existing information of the conflict,the Backjumping Algorithm is adopted to back to the variable which is the causes of conflict to continue scheduling,which reduces the range of invalid searching to a large extent.(3) Grid Scheduling Software research and study of experiment comparatively:Based on the above-mentioned theoretical studies,DELPHI and SQL Server 2000 are applied to research the Grid Scheduling Software and scheduling results visualization.Comparing with the traditional "first in,first out" algorithm, experimental study is adopted to analyze and sum up the advantages and disadvantages of the Grid Scheduling Algorithm.Of course,CNC resource sharing still exists a lot of problems to be research under the environment of Grid,this study analyzes the complicated associated constraints,describes the property of the tasks and resources nodes,establishes the optimization model from the point of CSP,study the Grid Scheduling Algorithms in the service model of "multi-task-to-multi-resource",so as to achieve the effectiveness of CNC resource sharing,and lay a good foundation for further research.