Design Of CNC Machine Thermal Error Automatic Measurement System Based On LabVIEW

The main equipment for precision and ultra-precision machining, High-end CNCmachine tools, is the cornerstone of industrial modernization. With the rapiddevelopment of manufacturing, CNC machining precision is increasingly demanding.Studies have shown that the thermal error of CNC machine tool is the largest errorsource in CNC machine processing, the proportion is as high as40%~70%. Therefore,reduce the thermal error of CNC machine tool is of great significance to improvemachining precision. This paper research on CNC machine thermal error, and havedeveloped a “CNC Machine Thermal Error Automatic Measurement System” based onLabVIEW, designed to integrated measurement of CNC machine temperature andthermal error. In addition, this system can also realize the function of thermal errormodeling online.The main work of this paper is as follows:(1) Realize the integrated measurement of CNC machine temperature andthermal error, build the hardware platform and write software programs for themeasurement system. Digital temperature sensor DS18B20and microprocessor systemArduino Uno built temperature measurement sub-system, inductive sensor and dataacquisition card USB5935built thermal error measurement sub-system. Useprogramming language LabVIEW and C, write sub-programs for temperature andthermal error measurement.(2) Introduce the common thermal error modeling method. Particularly,analyze the theory of Multiple Linear Regression(MLR) and use this theory for CNCmachine thermal error modeling. Write LabVIEW programs with this theory to realizethermal error modeling online.(3) Use LabVIEW Standard State Machine to write PC program for themeasurement system. Integrate the sub-functions of the system into the PC program asone of branch, so perform different functions is to switch corresponding branch. Addjudgment control logic and develop a friendly man-machine interface to make thesystem more intelligent and convenient.(4) Conduct thermal error modeling and compensation experiment andcommission Kunming Inspecting&Testing Center of Machine Tool Products of CMIFto identify this system for practicability, thermal error modeling precision andcompensation effect. Experiment and identification results show that the CNC machine thermal error greatly reduced and precision significantly improved after CNC machinethermal error compensation.