Positioning Error of Feed Axis Decouple-separating Modeling and Compensating Research for CNC Machine Tools

doi:10.3901/JME.2016.01.184

Abstract

Abstract: In order to establish a high-precision comprehensive position errors compensation model for CNC machine tools, a positioning error decouple-separating method is put forward. Temperature data and positioning errors are measured for 3-axis CNC machine tools, the variation of temperature fields and positioning error has been studied. Based on this regularity, a new concept of error-sensitive degree is defined, and constructs error-sensitive degree matrix by grey correlation algorithm, and optimizes the measurement point. Though the research of the position error variation, the thermal error and geometric basic error is decoupled and modeled each other by multiple linear regression and GM(1,n) algorithm. Then position error comprehensive model is established by linear superposition method. Though the on-line compensation experiment on VXC-560 type machine tools under different working conditions, the result shows that positioning error of x axis in cold-state is reduced from 11.1 μm to 4.5 μm, decreasing range is 59.5%.The positioning error of x axis in thermal state is reduced from 34.9 μm to 8.2 μm, decreasing range is 76.5%, and verifies the new compensation idea of directly driving hardware by a error model of machine tools. It has certain engineering application prospect.

Key words: compensation, decouple-separating, error model, positioning error-sensitive degree, the feed axis of machine tool

CLC Number:

TH161

YAO Xiaopeng, YIN Guofu, LI Guangming. Positioning Error of Feed Axis Decouple-separating Modeling and Compensating Research for CNC Machine Tools[J]. Journal of Mechanical Engineering, 2016, 52(1): 184-192.

References

[1] JOSEF M，JERZY J，ECKART U，et al. Thermal issues in machine tools[J] CIRP Annals Manufacturing Technology，2012，61(2)：771-791.
[2] RAMESH R，MANNAN M A，POO A N. Thermal error measurement and modeling in machine tools：Error compensation in machine tools-a review：Part II：Thermal errors[J]. International Journal of Machine Tools and Manufacture，2000，40(9)：1257-1284.
[3] 王海同，李铁民，王立平，等. 机床热误差建模研究综述[J]. 机械工程学报，2015，51(3)：119-128. WANG Haitong，LI Tiemin，WANG Liping，et al. Model of review on thermal error modeling of machine tools[J]. Journal of Mechanical Engineering，2015，51(3)：119-128.
[4] 要小鹏，殷国富，方辉. 五轴机床误差建模与补偿解析新算法研究[J]. 四川大学学报，2013，21(5)：1084-1089. YAO Xiaopeng，YIN Guofu，FANG Hui. A new synthesis error modeling and compensating algorithm of the five-axis machine tools[J]. Journal of Sichuan University，2013，21(5)：1084-1089.
[5] 张成新，高峰，李艳，等. 基于分段拟合的机床大尺寸工作台热误差补偿模型[J]. 机械工程学报，2015，51(3)：146-152. ZHANG Chengxin，GAO Feng，LI Yan，et al. Model of thermal error compensation of large size worktable for machine tools based on piecewise fitting [J]. Journal of Mechanical Engineering，2015，51(9)：146-152.
[6] 王维，杨建国. 基于插值算法的数控机床复合误差补偿技术[J]. 上海交通大学学报，2014，48(1)：12-15. WANG Wei，YANG Jianguo. Compound error compensation technique for CNC machine tools based on interpolation method[J]. Journal of Shanghai Jiao Tong University，2014，48(1)：12-15.
[7] 阳红，方辉，刘立新，等. 基于热误差神经网络预测模型的机床重点热刚度辨识方法[J]. 机械工程学报，2011，47(11)：117-124. YANG Hong，FANG Hui，LIU Lixin，et al. Method of key thermal stiffness identification on a machine tool based on the thermal error neural network prediction model[J]. Journal of Mechanical Engineering，2011，47(11)：117-124.
[8] ABULSHAHED A M，LONGSTAFF A P，FLETCHE S. The application of ANFIS prediction models for thermal error compensation on CNC machine tools[J]. Applied Soft Computing，2015，27(2)：158-168.
[9] ENEKO G A，AITOR O，JAVIER O，et al. Methodology for the design of a thermal distortion compensation for large machine tools based in state-space representation with Kalman filter[J]. International Journal of Machine Tools & Manufacture，2013，75(11)：100-108.
[10] CUI G W，LU Y，GAO D，et al. A novel error compensation implementing strategy and realizing on Siemens 840D CNC systems[J]. International Journal of Advanced Manufacturing Technology，2012，61(5-8)：595-608.
[11] The International Organization for Standardization. ISO 230-3-2007 test code for machine tools-Part 3 ：Determination of thermal effects [S]. Geneva：International Standard Organization，2007.
[12] LI Y X，YANG J G，GELVIS T. Optimization of measuring point for machine tool thermal error based on grey system theory[J]. International Journal Advance Manufacture Technology，2008(35)：745-750.
[13] ZHU Shaowei，DING Guofu，QIN Shengfeng，et al. Integrated geometric error modeling，identification and compensation of CNC machine tools[J]. International Journal of Machine Tools and Manufacture，2012，52(1)：24-29.
[14] LI Zihan，YANG Jianguo，FAN Kaiguo，et al. Integrated geometric and thermal error modeling and compensation for vertical machining centers[J]. International Journal Advance Manufacture Technology，2015，76(5-8)：1139-1150.
[15] FENG Wenlong，LI Zihan，GU Qunying，et al. Thermally induced positioning error modelling and compensation based on thermal characteristic analysis[J]. International Journal of Machine Tools and Manufacture，2015，93(6)：26-36.
[16] ZHANG Jianfu，FENG Pingfa，CHUANG Chen，et al. A method for thermal performance modeling and simulation of machine tools[J]. The International Journal of Advanced Manufacturing Technology，2013，68(5-8)：1517-1527.