基于多体系统理论的精密立式加工中心精度建模与预测

为了对机床加工精度进行事先预测并验证设计方案的合理性,分析了几何误差因素,基于多体系统理论建立了精密立式加工中心的精度预测模型。用拓扑结构和低序体阵列描述了多体系统间的关联性。基于齐次变换矩阵描述体与体之间的坐标变换关系,推导出多体系统中任意两相邻体之间各种运动的特征矩阵和相对运动方程,最终建立了精密立式加工中心精度预测模型,并以模拟加工典型试件为基础,实现了对机床的精度预测。预测分析表明,基于多体系统的精度建模可以有效抽象地描述精密立式加工中心的系统结构,并实现加工精度的合理预测,为机床设计方案的改进及精度分配提供了重要的依据。

Precision modeling and prediction of precise vertical machining center based on theory of multi-body system

In order to predict the machining precision of the machine tool and validate its design concept,the geometric errors of a precise vertical machining center were analyzed,and its precision prediction model was established based on the multi-body system theory.The correlations among the multi-bodies were described with the topology structure and the low-order body array.The coordinate transformation relationships between multi-bodies were described based on the homogeneous transformation matrix.The characteristic matrix and the relative motion equations of the motions between 2 arbitrary adjacent objects of the multi-body system were derived.A precision prediction model was built for the precise vertical machining center.Based on the simulated machining of a typical workpiece,the precision prediction of the machine tool was realized.The results showed that the proposed precision model can describe the systemic structure of the vertical machining center effectively and Abstractively,predict the machining precision reasonably,provide a basis for the improvement of the machine tool design concept and the precision deployment.