基于响应面方法的数控机床空间动态特性研究
Research on Machine Tool Spatial Dynamic Characteristics Based on Response Surface Method
作者：邓聪颖(重庆邮电大学 先进制造工程学院, 重庆 400065)；刘蕴(四川大学 制造科学与工程学院, 四川 成都 610065)；殷国富(四川大学 制造科学与工程学院, 四川 成都 610065)；王玲(四川大学 制造科学与工程学院, 四川 成都 610065)；林丽君(成都大学 机械工程学院, 四川 成都 610616)
Author：DENG Congying(School of Advanced Manufacturing Eng., Chongqing Univ. of Posts and Telecommunications, Chongqing 400065, China)；LIU Yun(School of Manufacture Sci. and Eng., Sichuan Univ., Chengdu 610065, China)；YIN Guofu(School of Manufacture Sci. and Eng., Sichuan Univ., Chengdu 610065, China)；WANG Ling(School of Manufacture Sci. and Eng., Sichuan Univ., Chengdu 610065, China)；LIN Lijun(School of Mechanical Eng., Chengdu Univ., Chengdu 610616, China)
收稿日期：2016-10-17 年卷（期）页码：2017,49(4):211-218
期刊名称：工程科学与技术
Journal Name：Advanced Engineering Sciences
关键字：机床动态特性;加工空间;响应面方法;固有频率
Key words：machine tool dynamic characteristics;machining space;response surface method;natural frequency
基金项目：国家科技支撑计划资助项目（2015BAF27B01）；重庆市教委科学技术研究资助项目（KJ1704087；KJ1600422）
中文摘要
机床运动部件位置姿态在加工空间的变化，造成机床质量矩阵、刚度矩阵以及阻尼矩阵随之变化，导致机床动态特性预测具有复杂性和不确定性。针对加工空间机床动态特性的准确预测问题，提出一种基于响应面理论的数控机床空间动态特性研究方法。该方法以数控机床固有频率这一关键动力学性能指标为例，分析机床整机动态特性与机床位置姿态之间的数学关联关系；基于正交试验设计和响应面方法理论，构建预测广义加工空间数控机床动态性能变化的响应面模型，揭示机床动态特性在加工空间的演化规律；并在该响应面模型基础上提出机床动态特性影响因子概念，计算各方向运动部件的位移变化对机床动态特性的影响程度，共同确定机床最优加工位姿和加工路线。将该方法应用于1台3轴立式加工中心，采用正交试验设计确定移动部件的不同位置组合作为计算样本点，在ANSYS仿真软件中计算每个样本点的前5阶固有频率，建立反映位置特征与固有频率数值的2次多项式响应面模型；并通过计算响应面模型质量评价指标验证了该模型的有效性，以此分析机床前5阶固有频率在加工空间的分布规律及其对x、y、z向位移变化的灵敏度，阐明机床空间位姿对机床动态特性有较大的影响，为机床工艺规划和优化设计提供了新的分析方法及技术支持。
英文摘要
Position changes of the machine tool's moving parts result in changes of the machine tool's mass matrix,stiffness matrix and damp matrix,which leads to the complexity and uncertainty for predicating the dynamic characteristics of the whole machine tool.Thus,a method to research machine tool's dynamic characteristics in the generalized machining space was proposed based on the response surface theory.In this method,the natural frequency was taken as the critical index to describe the whole machine tool dynamic characteristics,with which the mathematic relationship between dynamic characteristics and spatial poses were analyzed.Then,the orthogonal experiment design and the response surface method (RSM) were combined to establish the response surface model for predicating the varying dynamic characteristics,and their variation regularities in machining space were discussed.Furthermore,an algorithm was put forward to calculate the effect factors,which represented how the changes of each axial displacement impact on the dynamic characteristics of the whole machine tool.With the obtained variation regularities and effect factors,the optimal machining region and machining route were determined.The proposed method was applied in a three-axis vertical machining center to verify its feasibility.The various pose combinations of the moving parts were arranged as the samples by the orthogonal experiment design,and the natural frequencies related to the first five orders were acquired by conducting the modal analyses with the ANSYS software.Utilizing the acquired dynamic data,a second-order polynomial response surface model was established to describe the connections between the pose features and the natural frequencies.And the accuracy of the established model was validated after calculating the valuating indexes.Accordingly,this model was adopted to achieve the variation regularities and effect factors of the natural frequencies due to the displacement changes ofx,y,zdirections,which explained that the spatial poses affected the dynamic characteristics of the whole machine tool significantly,providing a theoretical support for the process planning and dynamic optimization of the machine tool.
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