| Summary: | 碩士 === 國立中興大學 === 機械工程學系所 === 105 === The thermal problem is the main reason of affecting the machine tool precision. Thermal distortion error of machine tool occupies most of the total processing error. Due to the gradually strict request of machine tool precision, the research of developing effective and steady thermal error compensation technique has become the main study of increasing the precision of machine tool these years. In terms of tool machine, spindle thermal error is the main resource of error. The study aims at carrying out compensation planning of spindle thermal error of gantry type five axis machine tool and establishing a set of online immediate compensation system to verify the feasibility of the system. The experiment initially uses different speed of un-virtual cutting to measure, and then set the "temperature sensor (Pt100)" and "eddy current sensor" on machine to capture temperature variation and thermal deformation variation. According to the collected experimental data, the study uses relevant analysis and selects the best combination of temperature points by stepwise regression, which effectively decreases the temperature point from 15 to 4, at last using Multivariate Linear Regression (MLR) to construct the compensation model. The study uses Arduino Mega 2560 single chip micro control board and bases on the compensation models to write the software procedure with C language. The compensation model mainly takes charge of calculating the compensation value and communicates with CNC controller, and then uses I/O to input the compensation value into controller, obtaining the thermal displacement compensation by shifting the zero point machine coordinate system. The result of the experiment shows that the thermal model in this study effectively controls the original thermal error from 100μm to ±10μm, increasing 90% of positioning precision.
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