摘要
热误差对数控机床尤其是高精度数控机床的精度影响严重,温度敏感点选择是建立热误差补偿模型的关键技术。而数控机床在主轴空转和实切状态下的热误差特性是不相同的。针对实切工况,提出了一种基于平滑数据干扰处理的稳健机床温度敏感点选择方法,大幅减小了由温度传感器噪声数据引起的温度敏感点变动性,通过6批次实切数据验证了这一方法的有效性。分别使用稳健性温度敏感点选择方法和非稳健性选择方法建立了2个热误差补偿模型,并对其进行了精度分析和比对。分析发现,因未考虑温度敏感点变动性而代入建立的模型会造成模型拟合精度、预测精度的损失。基于稳健机床温度敏感点选择方法的热误差补偿模型不仅可以保证模型稳健性满足实切工况需求,而且可以实现用2个温度传感器将模型的预测精度均值控制在10μm以内。
Thermal error has a serious impact on the accuracy of CNC machine tools,especially for high precision CNC machine tools.Selection of temperature sensitive points is the key technology to establish thermal error compensation model.The thermal error characteristics of CNC machine tools are different under the condition of idling and real cutting.In view of the real cutting condition,this paper proposes a robust temperature sensitive point selection method based on smooth data interference processing,which greatly reduces the temperature sensitive point variability caused by the noise data of temperature sensor.The effectiveness of this method is verified by six batches of real cutting data.In this paper,two thermal error compensation models are established by using robust temperaturesensitive point selection method and non-robust selection method respectively,and their accuracy is analyzed and compared.It is found that substituting the established model without considering the variability of temperature-sensitive points will result in a great loss of fitting accuracy and prediction accuracy of the model.The thermal error compensation model based on robust temperature-sensitive point selection method can not only ensure the robustness of the model to meet the requirements of real cutting conditions,but also realize the annual average prediction accuracy of the model controlled within 10 with only 2 temperature sensors.
作者
刘昀晟
苗恩铭
张明德
冯定
李建刚
LIU Yunsheng;MIAO Enming;ZHANG Mingde;FENG Ding;LI Jiangang(School of Instrument Science and Opto-electronic Engineering,Hefei University of Technology,Hefei 230009,China;School of Mechanical Engineering,Chongqing University of Technology,Chongqing 400054,China;School of Mechanical Engineering,Yangtze University,Jingzhou 434023,China;Harbin Institute of Technology(Shenzhen),Shenzhen 518055,China)
出处
《重庆理工大学学报（自然科学）》
CAS
北大核心
2020年第9期124-130,共7页
Journal of Chongqing University of Technology：Natural Science
基金
国家重点研发计划项目(2019YFB1703700)
重庆市技术创新与应用发展专项重点项目(cstc2019jscx-mbdx X0045,cstc2019jscx-mbdx X0016)。
关键词
数控机床
温度敏感点
实切
变动性
稳健性选择方法
CNC machine tool
temperature-sensitive point
real cutting condition
variability
robust selection method
