Abstract: Aiming at the problem of complex comprehensive error modeling and its poor adaptability,a CNC machine tool comprehensive error modeling method and error prediction method based on digital twin technology were proposed.Taking the three-axis CNC machine tool as the research object,the comprehensive error digital twin with the fusion of model and real-time data was established.A comprehensive error prediction model taking into account geometric error and dynamic error was established by using the method of multi-body dynamics and homogeneous coordinate variation,and the prediction model was expressed digitally to construct a digital twin model of comprehensive error based on data and model drive.To map the physical space in the digital twin with high fidelity,the data transmission framework based on TCP/IP communication protocol was constructed,and the two-way real-time mapping between the physical space and the digital twin was realized.The reliability of the comprehensive error prediction digital twin was verified by a three-axis CNC machine tool,and the real-time and stability of the data transmission was verified by the virtual and real synchronous motion experiment.The results provided a new way to construct error model of digital twin,and the theoretical foundation for comprehensive error modeling of the CNC machine tools.

Key words: digital twin, CNC machine tools, geometric error, comprehensive error

摘要： 针对数控机床综合误差建模复杂,模型适应性差的问题,提出一种基于数字孪生技术的数控机床综合误差建模方法及误差预测方法。为了建立模型和实时数据相融合的综合误差数字孪生体,以三轴数控机床为研究对象,首先采用多体动力学和齐次坐标变化相结合的方法,建立了考虑几何误差和动态误差的综合误差预测模型,并将预测模型进行数字化表达,以此构建基于数据和模型驱动的综合误差数字孪生模型。然后,为将物理空间高保真地映射到数字孪生体中,基于TCP/IP通讯协议构建数据传输框架,实现了数据在物理空间和数字孪生体之间的双向实时映射。最后通过三轴数控机床验证了综合误差预测数字孪生体的可靠性,同时利用虚实同步运动实验验证了数据传输的实时性和稳定性。研究结果为构建误差模型数字孪生体提供了一种新途径,并为实现数控机床的综合误差动态预测提供了理论基础。

关键词: 数字孪生, 数控机床, 几何误差, 综合误差