Study On Optimization Model And Methods Of CNC Machining System Based On Generalized Energy Efficiency

As a super country in manufacture industry, China holds a significant proportion of total energy consumption in manufacturing sector. The manufacturing sector in China, with the characteristics of large amounts of energy consumption, serious pollution and high carbon emissions, is facing the most challenging issue. The CNC machining system, which is made up of CNC machines, workpieces, cutting tools, fixture tools, supporting equipments etc., involves a great deal of energy transformation and material consumption. With the increasing of numerical control rate in machining system, it is necessary to study the energy performance of CNC machining and establish the optimization model on the view of system, in order to improve and enhance the energy efficiency.Combining with the project financed by the National High-Tech R&D Program of China(863 Program)(No. 2014AA041506) and National Natural Science Foundation of China(No. 51475059), optimization framework and methods of CNC machining system based on generalized energy efficiency are studied in this paper.Firstly, the definition and calculation modle of generalized energy consumption are presented based on analyzing the characteristics of the energy consumption of NC machining system, which is classified into direct energy and indirect energy. Then the conception and connotation of generalized energy efficiency is put forward, which can be expressed as energy utilization rate or specific energy. The optimization framework considering generalized energy efficiency of CNC machining system is established based on process parameters, process route and job shop scheduling view.The generalized energy efficiency model for process parameters is presented on the strength of which an optimization model target on process time and energy efficiency is built. By introducing and improving the genetic algorithm(GA) to solve this problem, a series of simulation experiments are implemented. The rules of energy efficiency changing with process parameters are discussed and the energy conservation effort of proposed model is verified.Thirdly, the generalized energy efficiency model for process route is built, based on wihic the optimization modle is then presented. A modified non-domination GA is adapted to solve this optimization problem with energy efficiency and time efficiency objectives. A simulation exprement of real cylindrical gear process route optimazation is conducted to validate the optimal performance.The generalized energy efficiency is also being put forward to job shop scheduling problem. With the optimization model, the makespan and generalized energy consumption are considered as objectives. The benchmark problems are optimized and the relation between energy efficiency and schedule schem is discussed.Finally this paper introduces a kind of energy efficiency optimization software for CNC machining system based on generalized energy efficiency. This system can help users to search collecet and manage the technique information and energy date, it also can provide a set of optimal scheme of process paremetors, process route and job shop schedule.