五坐标机床误差因素全局灵敏度分析方法研究

Research on global sensitivity analysis method of the error factors of the five coordinate machine tool

国产五坐标机床的加工精度和加工性能是目前机床制造厂商面临的重要难题,零部件几何误差是造成机床加工误差的关键因素之一。首先,利用多体系统运动学理论对机床结构进行抽象描述,推导机床精密加工约束方程及加工误差模型。其次,将基于方差的全局灵敏度分析法引入机床误差分析中,通过蒙特卡洛采样法模拟各项几何误差取值过程,计算各输入变量的灵敏度指标。利用Matlab编写软件,以北一机床XHAV2430×80龙门加工中心的加工误差模型为例进行灵敏度分析,计算影响加工误差的各项机床几何误差源参数的灵敏度指标。最后根据计算结果,获得影响机床加工误差的关键因素。对计算结果进行验证,证明了结果的正确性,为机床加工误差溯源提供重要理论依据。

The precision and performance of domestic five coordinate machine tools are the most important research topics to the machine tool manufacturers nowadays. Parts geometric error is one of the key factors that lead to machining errors. First,using the multi-body system theory to deduce the precision machining constraint equation and the machining error model. Second,the variance based global sensitivity analysis method is introduced to analyze the error of the machine tool,simulating the sampling process of geometric error by the Monte Carlo method to calculate the value of the sensitivity index. Then,using Matlab to write software,taking the XHAV2430x80 gantry machine tool that made by BYJC as an example to analyze the sensitivity of the machining error model,and calculating the sensitivity index of the geometric error that influences the machining error. Finally,according to the calculation results,the key factors affecting the machining error are got. The result is proved to be correct which can provide an important theoretical basis for tracing the machining error source.