摘要
空间误差建模和补偿已成为提高机床精度和性能的最经济方法之一。然而,空间误差元素测量耗时多等原因限制了空间误差补偿的广泛应用。为解决这一问题,提出了一种基于灵敏度分析的空间误差快速建模和补偿方法。首先,基于齐次坐标变换,建立了立式加工中心的广义运动学模型。其次,根据立式加工中心的所有误差元素的灵敏度分析,确定关键误差元素。根据灵敏度分析结果,在误差补偿过程中忽略了影响因子较低的角度误差元素。然后,基于关键误差元素的测量数据和切比雪夫多项式,建立了简化的空间误差快速补偿模型。接着,利用Fanuc数控系统的EMZPS功能开发了实时误差补偿系统,实现了空间误差的补偿。为了评估所提方法的有效性,对每个平动轴和每条体对角线误差补偿前后的测量试验结果进行比较。结果表明,沿三个轴的最大平移误差从21.9μm到6.5μm,最大体对角线误差从81.6μm减小到35.5μm。最后,将该方法应用于一批20个立式加工中心,进行批量补偿试验。所有加工中心补偿后的精度均优于40μm。本研究的创新之处在于将灵敏度分析作为简化机床误差模型的理论依据,并提出了出一种快速批量化建模和补偿的方法。该方法能有效提高误差补偿效率,在未来机床误差补偿的广泛工业应用中有着巨大的潜力。
Volumetric error modelling and compensation has become one of the most cost-effective ways to improve the accuracy and performance of machine tools. However, the time-consuming measurement process limits its application. Hence, a volumetric error rapid modelling and compensation method based on the sensitivity analysis is proposed. Firstly, a generalized kinematic model of the vertical machining center is established. Then the most important key error components are determined according to the sensitivity analysis of the all error components, while the less important angular errors can be neglected. Consequently, all key error components are measured and modelled with Chebyshev polynomials, and further applied in a real time error compensation system. To evaluate the effectiveness of this method, the positioning errors alone each translational axis and body diagonal lines with and without error compensation are compared. The former is greatly reduced from 21.9 μm to 6.5 μm, while volumetric error similarly reduced from 81.6 μm to 35.5 μm. Finally, this method is applied into 20 vertical machining centers, all improved to less than 40 μm. This paper innovatively uses sensitivity analysis as the theoretical basis for simplifying machine tool error models, and proposes a rapid modeling and compensation method for batch of vertical machining centers. This method can effectively improve the error compensation efficiency, which shows great potential in the future industrial applications.
作者
杨赟
朱梦瑞
李慧敏
杜正春
杨建国
YANG Yun;ZHU Mengrui;LI Huimin;DU Zhengchun;YANG Jianguo(School of Mechanical Engineering,Shanghai Jiao Tong University,Shanghai 200240)
出处
《机械工程学报》
EI
CAS
CSCD
北大核心
2020年第7期204-212,共9页
Journal of Mechanical Engineering
基金
国家自然科学基金(51975372,51527806)
国家科技重大专项(2015ZX04005001)
国家重点研发计划(2018TFB1701204)资助项目。
关键词
空间误差
灵敏度分析
分步体对角线
批量加工中心
实时误差补偿
volumetric error
sensitivity analysis
body diagonal error evaluation
batch of CNC machining centers
real-time error compensation