基于元动作单元的数控机床运动精度映射

Kinematic accuracy mapping of NC machine tools based on meta-action units

摘要:

为使数控机床精度设计有定量的理论数值供参考,从运动的角度出发,建立了基于元动作单元的数控机床运动精度映射模型. 采用“功能(Function)-运动(Motion)-动作(Action), FMA”的结构化分解方法得到元动作单元,并结合多体系统理论对数控机床拓扑结构进行了描述；运用旋量理论对数控机床误差建模,建立数控机床空间运动误差模型,并用螺旋理论得到空间运动误差综合值；以制造成本、空间运动误差螺距及其大小为设计准则,构建了运动精度映射模型,并应用NSGA-Ⅱ遗传算法对数控机床运动精度进行映射. 对某国产加工中心进行运动精度映射求解,说明了该模型的可行性和有效性.

Abstract:

To make the numerical control machine precision design have quantitative theoretical values for reference, the kinematic accuracy mapping model of NC machine tools based on the meta-action unit is established from the perspective of motion. The functional decomposition method of "Function-Motion-Action, FMA" is used to obtain the meta-action unit, and the topology of the NC machine tool is described in combination with the multi-body system theory. Using the theory of spin quantity the error of NC machine tools is modeled, the spatial kinematic error model of NC machine tools is established, and the comprehensive value of spatial kinematic error by spiral theory is obtained. Based on the manufacturing cost, spatial kinematic error pitch and its size, the kinematic accuracy mapping model is constructed, and the NSGA-II genetic algorithm is used to map the kinematic precision of NC machine tools. Finally, the kinematic accuracy mapping of a domestic machining center is solved, and the feasibility and effectiveness of the model are illustrated.