并联机床平面约束机构误差分析与建模

针对五轴数控机床平面约束机构进行了误差分析,指出了并联机床平面约束机构误差主要影响因素为机构的制造误差和安装误差·前者与由其引起的约束机构顶边中点沿x方向的位移成非线性关系,而后者则成线性关系·提出了一种依据测量数据反演非线性误差模型的建模方法,给出了五轴并联机床约束机构实测信息与模型输出间的多项式误差模型·比较仿真结果与测量结果可知,基于上述方法建立的误差模型精确,进而利用该模型对机床进行实时精度补偿,可使机床x方向定位精度大为提高

Error Analyzing and Modeling of Six-bar Linkage Mechanism in the Parallel Machine Tool

The errors on the six bar linkage mechanism in the parallel machine tool with 5 DOF were analyzed. The main cause of the errors is manufacturing errors and installing errors of the mechanism. The relation between the former errors and the displacement of the middle point on the top edge of the six bar mechanism in the x axis is nonliear, and the relation between the later errors and the displacement is linear in the x axis. A nonlinear error modeling method based on measuring data was presented. The error polynomial function between measuring information and output of the error model was set up. With comparing the results of measuring and emulating, the model based on the method is accurate. Using the model to compensate the parallel machine tool can raise its accuracy in the x axis greatly.