基于改进分段三次Hermite插值的机床复合误差建模与补偿

Comprehensive error modeling and compensation for cnc machine toolsbased on improved piecewise cubic Hermite interpolation algorithm

为降低精密卧式加工中心几何误差与热误差而产生的复合误差,文中提出一种基于改进分段三次Hermite插值(improved piecewise cubic Hermite interpolation, IPCHI)算法的复合误差建模方法。为建立复合误差模型,在JIG630精密卧式加工中心上开展试验,采用温度传感器和激光干涉仪分别获取机床温度值和定位误差分析整个温升过程中的误差数据,总结误差分布规律,运用IPCHI算法识别并建立几何误差和热误差的数学模型。运用复合误差模型进行补偿实验,精密卧式加工中心常温下的最大定位误差从-10.1μm降至2.3μm,补偿77%;温升之后定位误差从-19.8μm降至2.6μm,补偿87%,验证了IPCHI模型在实际误差补偿中具有明显的补偿效果。

In order to reduce comprehensive error of geometric error and thermal error of precision horizontal machining center,a comprehensive error modeling approach based on improved piecewise cubic Hermite interpolation(IPCHI)algorithm is proposed.Error measurements test are carried out on a JIG630 precision horizontal machining center to establish the comprehensive error model of the machine tool.Temperature sensor and laser interferometer are used to measure the error data of temperature and error of machine tool respectively in the process of temperature rise.The error distribution law is summarized,and the mathematical models of geometric error and thermal error are established by using the IPCHI algorithm.The maximum positioning error in normal temperature is reduced from-10.1μm to 2.3μm by using the comprehensive error model,which is compensated 77% compared with no compensation. After the temperature rise, the maximum positioning error is reduced from-19. 8 μm to 2. 6 μm, which is compensated 87%. The validity of IPCHI model in error compensation of precision horizontalmachining center is verified.