嵌入式数控机床热误差补偿装置设计与实现

The Design and Implementation of Thermal Error Compensation Device of CNC Machine Tool Based on Embedded System

为减少热误差对数控机床加工精度的影响,针对华中数控HNC-848型数控系统机床设计了一种嵌入式热误差补偿装置。该装置采用基于STM32+FPGA的嵌入式系统设计方法,实现机床温度数据获取、热误差建模、热误差补偿执行等功能。利用采集的前2 160组优化后机床测温点数据在STM32处理器内进行多元线性回归热误差建模,后2 160组优化后数据进行热误差预测。测试结果表明该装置热误差预测效果良好。通过在机床数控系统编写补偿子程序,利用该热误差补偿装置,实现了热误差实时补偿功能。

In order to reduce the influence of thermal error on the machining accuracy of CNC machine tool, a thermal error compensation device based on embedded technology was designed, which aimed at machine tool equipped with HNC- 848 numerical control system. The device adopted the embedded system design method based on STM32＋FPGA to realize the function of temperature data acquisition, thermal error modeling, thermal error compensation and so on. First, used the 2 160 groups of optimized data collected from the temperature measuring point of machine tool to process thermal error modeling based on multiple linear regression in the STM32 processor, and second used the remaining 2 160 groups of optimized data to process thermal error prediction. The experimental results show that the thermal error prediction of the device is effective. By writing the compensation subroutine in the numerical control system, the thermal er ror compensation device can be used to realize the real-time compensation of thermal error.