高精度五轴龙门数控加工中心综合误差建模与辨识

Comprehensive Error Modeling and Identification of High Precision Five-axis Gantry CNC Machining Center

针对五轴数控机床在加工过程产生的多类别融合误差影响着机床加工精度的问题,提出一种基于误差耦合的综合误差模型建立方法。从误差源的角度出发,分析影响机床加工精度的主要因素,探究不同误差对机床加工精度的影响。在此基础上建立了目标机床的拓扑结构和低序体阵列,从而完成了基于多体系统理论的理想状态和实际状态下的综合误差齐次坐标变换矩阵的推导,由此建立起目标机床的综合误差模型,并给出了综合误差模型正确性的验证。提出了一种先插值后拟合方法对五轴数控机床误差进行拟合。实验结果表明,该方法可有效地处理误差波动较大的数据,相较而言,拟合偏差降低了3.04%,提高了五轴数控机床综合误差模型精度。

Aiming at the problem of multi-class fusion errors affecting machining accuracy of five-axis CNC machine tools,a comprehensive error model based on error coupling is proposed.From the angle of error source,the main factors affecting the machining accuracy of machine tools are analyzed,the influence of different errors are explored on the machining accuracy of machine tools.On this basis,the topological structure and low sequence array of the target machine tool are established,and the homogeneous coordinate transformation matrix of synthetic error under ideal and actual state based on the theory of multi-body system is completed.The synthetic error model of the target machine tool is established,and the correctness of the synthetic error model is verified.A method of interpolation before fitting is proposed to complete the fitting of the errors of five-axis CNC machine tools.Experimental results show that the proposed method can effectively process the data with large error fluctuation,and the fitting deviation is reduced by 3.04%,which improves the accuracy of the comprehensive error model of five-axis CNC machine tools.