| Friction stir welding machine is an important processing equipment for automatic connection of large plate and complex parts such as aerospace,Marine,rail train,etc.It makes use of the high-speed rotation of the stirring head and the friction heating of the workpiece to melt the base material,and uses the stirring head to push forward to generate welds.Compared with traditional welding,its weld heat affected zone is smaller,the residual stress is low,the workpiece is not easy to deformation,and the automation degree is high,no pollution,so it has become a new plate connection method at the present stage.At the present stage,the CNC system of friction stir welding machine tool used in China is mostly Germany Siemens general CNC system.Its complex electrical structure,more software redundancy modules,not strong targeted,making the user difficult to operate,and expensive,for aerospace and other military occasions,there are many security and confidentiality problems.The centralization of the reason for this special system,specificity,low cost,high precision,break the foreign numerical control system technology monopoly,the enhancement enterprise goals such as independent research and development ability,this paper has carried out the lean type numerical control system of friction stir welding machine research,designed to electrical structure of movement control CARDS combined with industrial control,and the software function modular design and development;The kinematics model of FSW machine tool is studied to realize the control machining of two dimensional plane,and the state detection and diagnosis function of the system is developed.The specific research work includes:(1)Analysis of the gantry friction stir welding machine,the mechanical structure and movement principle of motion control card and PC based control method to design the equipment of general electric structure and the key parts and parameter selection and set,including: motion control card,servo motors,drives,encoder and type selection calculation and application of electronic gear ratio;The variable frequency speed regulation of spindle asynchronous motor is introduced.The least square method is used to polynomial fit voltage and speed to achieve speed control requirements.The software system is designed by modular design method,and the overall workflow of the system is described.(2)The model of the mixing head was simplified and the weld path was analyzed.The solution method of the tool's inclination direction was deduced in the workpiece coordinate system.Based on d-H parameter method,the series mechanism of5-axis gantry FSW machine tool was simplified,and the D-H parameters of connecting rod and joint of the machine tool were obtained.Through forward and inverse kinematics,the inverse general solution of tool in the workpiece coordinate system is derived.The common NC codes are analyzed and summarized,and an intelligent parsing algorithm is proposed,which includes preprocessing function,phrase detection function,grammar detection function and data storage module of NC codes.The tangent following function of C-axis at inflection point is designed.Finally,the function of motion control card is introduced,and the corresponding motion module of handwheel is developed.(3)Based on the electrical structure of FSW plane and the actual demand,the monitoring signal is reasonably distributed.The modularization design of monitoring function is carried out,and the communication protocol adopted by monitoring module is described.The alarm monitoring scheme of master and slave station of host computer,driver and frequency converter is optimized.The fault tree model of FSW private jet system was established based on fault tree analysis method.Semanders method was used to solve the minimum cut set of system faults and the diagnosis module was developed.The two-layer C/S architecture was used to realize the cause and solution push of drivers and transducers based on fault codes.(4)According to the characteristics of lean friction stir welding machine,based on.NET Framework platform,SQLite database,developed the corresponding system function modules,took the five-axis gantry friction stir welding machine tool of An aerospace manufacturing enterprise,LTD as the verification platform,carried out welding experiment processing,verified the feasibility of the relevant algorithm,effectively reduced the cost of the software system.The system is open and friendly. |
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