| Turbine blade is the core component of aeroengine.It works in the most severe part of engine environment,where the ambient temperature is above 1600℃.The cooling technology can improve the high temperature resistance of the blades and the overall performance of the aircraft.Chinese multi-type aero engines have been made in China,but the production capacity of aero blades is seriously insufficient.In order to improve the blade yield,it is necessary to choose the appropriate processing mode,design reasonable production line and special CNC system of machining machine tool,and combine the actual design scheduling strategy of the production line to improve the production management mode,so as to achieve the purpose of improving the processing efficiency.The single-machine control system of seven-axis EDM small hole machine adopts the structure of up and down machine.The upper computer takes ARM chip RK3399 as the core,including external communication module,discharge state detection module,servo feed module;The lower computer uses STM32 single chip microcomputer as the main control chip,including the keyhole machining module,pulse power module,working liquid circulation module and external communication module.The upper and lower computer communicates through CAN bus.In this paper,the pulse power control circuit and servo control scheme of small hole machining are designed.The task requirements of NC machine tools are analyzed and the priority of each task is assigned.The NC system of machine tools is developed by Qt software of Linux system based on C/C++ language.The CNC system chooses multi-process architecture to write,and realizes GUI human-computer interaction,external communication,G code interpretation,interpolation,discharge state detection,motion control and other tasks.The EDM small hole machine is composed of the electric machining production line of aviation blades,and can realize automatic loading and unloading and workpiece transfer work in the production line through industrial robots,so that the workpiece is processed according to the process flow of measurement-punching-molding.The workpiece cache area inside the production line is used for temporary storage of the workpiece to be processed to prevent station blocking.On the basis of basic automation,in order to greatly improve the production efficiency through scientific production management methods,this paper combined with the characteristics of EDM and the machining process of aeromedm blades,carried out research on the flexible production of aeromedm blades.The production line control system of aerojet blade needs to obtain the production plan from the scheduling subsystem,and according to the plan,give instructions to the small hole machine and other single equipment,and then the single equipment will feed back its processing status information to the production line control system.In case of jamming and interference,the production line control system will send the interference information to the scheduling subsystem and get a new production plan.This paper introduces the relationship and data exchange mechanism among production line control system,single machine numerical control system,scheduling and rescheduling subsystem.According to the analysis,the electric machining line of air turbine blade belongs to the flexible assembly line with handling time and limited buffer zone.Considering that the assembly line is affected by various random factors,the workpiece processing time cannot be predicted accurately and the electrode needs to be changed frequently,the scheduling optimization problem of the flexible assembly line with handling time with multiple sequences limited buffer zone was studied.In this paper,an improved genetic algorithm is designed to solve these problems,and a matrix coding method for scheduling solutions is designed.This paper improved the selection strategy of genetic algorithm by merging two generations of parent and son population,increased the diversity of population and improved the global nature of the algorithm.The method of grouping and comparison selection is adopted to avoid the loss of elite individuals of the parent generation.The rescheduling scheme of electric machining production line of aero turbine blades was planned to cope with various random factors,such as machine failure,insertion,withdrawal and processing delay.Finally,through the simulation test,the improved genetic algorithm can solve the scheduling optimization problem with handling time and multi-sequence finite buffer.Taking the iteration times when the algorithm gets the final scheduling scheme as the reference standard,the optimization efficiency of the improved genetic algorithm is 36.9% higher than that of the classical genetic algorithm.The designed rescheduling strategy has been verified by experiments and can effectively deal with the abnormal situation in the production process. |
PDF Full Text Request