基于机电建模的加工中心轴间耦合问题
Multi-axis coupling of machining centers based on electromechanical modeling

加工中心加工精度与其整机结构特性和各轴控制特性密切相关。考虑进给轴间的动态激励响应，研究加工中心整机在特定频率范围内的各向动柔度，对辅助机床设计具有重要意义。该文结合有限元建模和相关实验方法，分析了某双驱进给平台的结构动柔度，重点研究其机械系统的轴间耦合问题。提出了一种用传递函数组等效机械结构特性的整机机电联合仿真建模方法，并以此研究了某卧式加工中心机电系统的轴间耦合问题。研究结果表明：当加工中心存在某些模态振型同时影响刀具或工件在多方向的变形时，其机械系统和机电系统的轴间耦合在整机动柔度研究和控制环参数选择时必须予以考虑。
Abstract：The dynamic accuracy of a machining center is strongly influenced by its structural dynamics and control loops. The frequency response of the entire machine including the multi-directional dynamics is important in the machine tool design phase. The structural dynamics of a twin ball screw feed machine are analyzed using a finite element analysis (FEA) and measurements with a focus on the multi-axis coupling of its mechanical system. Then, an electromechanical modeling method is developed where the structural dynamics are replaced by transfer functions to study the multi-axis coupling of the electromechanical system of a horizontal machining center. The results show that when there are modal shapes leading to displacements of the tool or the workpiece in multiple directions, the multi-axis coupling of the machining center must be considered in studies of the dynamics and control parameters.