Efficient parameterization of structural dynamic main spindle models

在工业4.0和数字孪生的背景下，关于机床运行过程中组件属性的信息变得越来越重要。主轴及其性能在机械加工中起着非常重要的作用。在对加工质量敏感的应用中，如状态监测或过程力测量，作为机床的重要组成部分，了解主轴的当前物理特性非常重要。主轴结构动力特性在运行过程中受到各种力学和热弹性效应的影响，其监测和基于模型的映射是一项艰巨的任务。为了能够识别主轴的静态和动态特性，在主轴中集成了传感器，以测量主轴轴与主轴壳之间的相对位移。本研究项目旨在开发和研究一种模拟主轴弹性特性的模型的有效过程并行参数化方法。模型的初始参数化是基于附加测量装置的仿真和实验。该自适应模型考虑了与加工过程相关的结构动态特性变化，该模型基于主轴集成传感器信息和机器内部数据。本研究定义了两种方法来识别结构在运行过程中的动力特性。第一种方法侧重于基于同时获取主轴轴位移和由机器内部数据识别的过程力来识别结构动态特性。这种方法可以计算主轴系统的静刚度，也可以间接确定主轴系统的动态特性。第二种方法是基于对标准机床内部功能（如换刀、快速遍历等）执行过程中结构动态主轴特性的识别。在执行这些标准功能时，机械载荷会影响主轴。对这些载荷的分析确定了主轴的实际结构动力特性。利用力测量平台测量的过程力对方法进行了验证，并在参数化模型的基础上进行了确定。该方法可在过程相关频率范围内的宽负载谱范围内进行验证。

Information about the properties of the components of a machine tool during operation becomes increasingly important in the context of the topics Industry 4.0 and Digital Twin. The main spindle and its properties are very important in machining. In the context of machining-quality-sensitive applications, such as condition monitoring or process force measurement, knowledge of the current physical properties of the main spindle, as an important component of a machine tool, is of great importance. The structural dynamic properties of the main spindle are influenced by different mechanical and thermo-elastic effects during operation, whose monitoring as well as model-based mapping represent a demanding task. To enable the identification of the static and dynamic properties of the main spindle, sensors are integrated into the spindle in order to measure the relative displacement between the spindle shaft and the spindle housing.This research project aims to develop and investigate a method for the efficient process-parallel parameterization of a model, which simulates the elastic properties of the main spindle. The initial parameterization of the model is based on a simulation and experiments with additional measurement setups. The process-related changes in the structural dynamic properties are taken into account in the adaptive model based on the information from the spindle-integrated sensors and the machine-internal data. Two approaches are defined in this research project for the identification of the structural dynamic properties during operation. The first approach focuses on the identification of the structural dynamic properties based on the simultaneous acquisition of the displacement of the spindle shaft and the process forces identified with machine-internal data. This approach allows the calculation of the static stiffnesses of the main spindle system as well as the indirect determination of its dynamic properties. The second approach is based on the identification of the structural dynamic spindle properties during the execution of standard machine-internal functions, such as tool change, rapid traverse, etc. During the execution of such standard functions, mechanical loads affect the main spindle. The analysis of these loads identifies the actual structural dynamic properties of the main spindle. The validation of the methods is carried out with the aid of process forces measured by means of a force measuring platform and determined on the basis of the parameterized model. With this procedure, the method can be validated in a wide loads spectrum in process-relevant frequency ranges.