Research On Temperature Control System Of Self-resistance Electrical Heating Incremental Forming

Metal sheet incremental forming is a flexible die-less forming technology which combines rapid prototyping manufacturing with plastic forming.Aiming at the urgent need of personalized small batch structural parts in aerospace field,the advantages of die-less forming technology can replace the traditional forming process to form complex thin-walled aerospace structural parts with high structural flexibility.In recent years,the demand for light alloy sheet metal parts has been increasing in the field of aerospace.In order to solve the manufacturing problem of this kind of Aeronautical refractory structural parts,a single-point self-resistive electric heating progressive technology has been proposed in recent ten years,which effectively solves the drawbacks of in-furnace heating progressive forming.Compared with single-point self-resistive electric heating incremental forming technology,integral self-resistive electric heating incremental forming technology can significantly improve the temperature uniformity of sheet metal,and hopefully achieve the technological leap and innovation of precise forming of complex surface structural parts of light alloy materials.However,various studies have shown that the temperature control in the forming process has become the key point to further improve the forming limit of light alloy materials.Therefore,the development of a real-time temperature monitoring system to control the temperature of the forming area,so as to improve the forming limit of the forming parts has become an urgent problem to be solved.The solution of this problem plays an important role in the application and promotion of this technology in aerospace manufacturing industry.In this paper,a temperature control system for TC4 titanium alloy incremental forming by integral self-resistive heating is developed based on the technological characteristics of integral self-resistive heating incremental forming.The main research work is as follows:1.Based on the characteristics of integral self-resistive electric heating incremental forming process,the overall design of temperature control system was carried out.The temperature field in the whole self-resistive electrical heating incremental forming process zone was studied by combining finite element simulation with experimental verification,and the heating electrodes which made the temperature field in the process zone more uniform were obtained.Furthermore,the whole self-resistive electric heating incremental forming device is designed,and the temperature sensor and the software and hardware platform of the temperature control system are designed and selected.2.The algorithm of temperature control system is studied.The commonly used PID control algorithm,fuzzy control algorithm and fuzzy self-tuning PID control algorithm in industrial control field are summarized in detail.The temperature control simulation model based on the above algorithm is designed by using the MATLAB/Simulink module,and the temperature control algorithm suitable for the temperature control system in this paper is obtained by comparing the simulation results.3.The software of temperature control system is designed based on embedded Linux platform.The embedded Linux development environment is built.The embedded Linux drivers used in temperature control system,U-boot,Linux kernel and file system are transplanted on 2440 hardware platform.The application program of temperature control system is developed based on Qt/Embedded platform.4.Experimental verification of temperature control system.The accuracy of the temperature control system designed in this paper is verified by a comparative experiment,which proves that the temperature control system in this paper is helpful to improve the forming limit of incremental forming process.