Research And Implementation Of Thermal Error Compensation System For Heavy-duty Planer Drilling Machine

With the further development of China’s industrial construction,the requirement of machinery manufacturing in all industries is being improved.The high precision CNC machining technology represents the degree and level of modernization of national manufacturing.It has important strategic significance to promote the upgrading of manufacturing equipment.Improving the processing precision of CNC machine tools has become an important subject in the field of mechanical manufacturing.Heavy-duty CNC machine tools has the characteristics of large volume,longer running distance,heavy load,limited manufacturing and installation precision of large structural parts,serious heating of driving devices.So it is easy to produce large machining error in processing.Research shows that the error caused by the thermal deformation of machine tools occupies a larger proportion of the total error.Especially in precision machining,thermal error is the main part of machining error.Therefore,it is very important to improve the processing precision of CNC machine tools by reducing the thermal error.This paper takes ZK5540 A heavy-duty planer drilling machine as the object,and studies the compensation of thermal error.Based on the research of thermal error compensation strategies and methods,design and implement a set of embedded thermal error compensation control system.The main research work is as follows:(1)Research on multimodal access strategy for thermal error compensation and implementation method for reducing thermal error of CNC machine tools.Analyze the HNC-848 numerical control system of ZK5540 A heavy-duty planer drilling machine,propose three kinds of thermal error compensation methods: feedback signal truncation method,integrated thermal error compensation method of numerical control system and G code dynamic modification thermal error compensation method.Based on theoretical study and comparative analysis of the three compensation methods,adopt the last method to carry out the design of thermal error compensation system.(2)According to the G code dynamic modification thermal error compensation method,the implementation plan of thermal error compensation control system is worked out.To meet the system requirements,a thermal error compensation controller is designed based on ARM+FPGA embedded system.Layout the hardware circuit of temperature data acquisition,operational data storage,error data communication,and present compensation system software design on this basis.A thermal error prediction model based on BP neural network is established and embedded in the STM32 microprocessor.(3)System test and verification of thermal error compensation controller.Set up the experimental platform of thermal error compensation system,connect the compensation controller to ZK5540 A heavy-duty planer drilling machine,configure numerical control system and redevelop PLC software.To ensure the effectiveness of thermal error compensation system,carry out the unit test of bus communication module,and design a thermal error compensation experimentation based on BP neural network to test the whole system.