Integrated Optimization Of Process Planning And Task Dispatching In Machining Workshop

In the traditional machining workshop,process planning and task dispatching are two serial and separated parts performed by experienced engineer and manager.Due to craft flexibility and machine flexibility in machining workshop,it's hard to grasp the overall situation of all workpieces and machines.As a result,manual decision may probably lead to resource conflict and bottleneck.Aiming at the above problem,a Manufacturing Execution System for machining workshop was supposed to be developed.An integrated optimization problem was abstracted from this engineering problem,which considered process planning and task dispatching at the same time.Scheme that takes shorter time could be elected from numerous combinations of craft and schedule.The research was divided into the following three parts: modeling,algorithm designing,and programing.Firstly,a method to describe machines and layout was presented in consideration of clamping time,unclamping time and transporting time.A method to describe craft of workpieces was presented in consideration of craft flexibility.The mathematic model of the integrated optimization problem was built in consideration of clamping,unclamping,transporting and craft constraint.Secondly,a solving algorithm based on ant colony was proposed according to the above describing methods and mathematic model.The pheromone updating function of traditional ant colony algorithm was improved to promote the performance.Lastly,as a part of the MES,a scheduling software module was programed according to the designed algorithm and verified with a real case.