Measurement and evaluation of the volumetric accuracy of multi-axis machine tools under operational conditions

机床的工作精度直接影响到加工产品的质量。评价一台机床的操作能力的一个重要标准是其在加工过程中尽可能准确地假定刀具中心点（TCP）的指定位置和刀具的空间方向的能力。这种空间运动精度受到几何和运动学偏差的限制。这些包括，例如，机械组件的制造精度，静态，动态和热影响，以及摩擦或润滑的影响，以及加工过程的设置变量的影响。本课题的研究目的是开发一种基于双球杆（DBB）测量原理的机床空间运动精度的确定和校正新方法。该方法必须适用于自检，也就是说，它应该能够快速执行和自动化测试，而无需在加工中断期间准备运行的机器上进行昂贵的转换。此外，不应要求有专门资格从事这些测量任务的人员。要使用的测量设备必须对测量任务足够精确，易于操作，在加工环境中使用坚固耐用并且价格低廉。在第一阶段，开发了具有扩展测量范围的DBB测量系统，创建了测量系统数据与试验机实际轴值同步采集的先决条件，并制定了误差敏感空间测量路径生成的基础。第二阶段的目标是通过识别和修正测量数据中的运动误差来提高空间路径精度。

The working accuracy of a machine tool directly influences the quality of the manufactured products. An essential criterion for evaluating the operational capability of a machine tool is its ability to assume the specified positions of the tool centre point (TCP) and the spatial orientation of the tool as accurately as possible during machining. This spatial movement accuracy is limited by geometric and kinematic deviations. These include, for example, the manufacturing accuracy of the mechanical assemblies, static, dynamic and thermal influences as well as influences from friction or lubrication and from the setting variables of the machining process. The aim of the research project is to develop a new method for determining and correcting the spatial movement accuracy of a machine tool based on the double ball bar (DBB) measurement principle. The method must be suitable for self-testing, i.e. it should be possible to carry out and automate it quickly and without costly conversions on machines that are ready for operation during breaks in machining. Moreover, it should not require personnel specially qualified for these measuring tasks. The measuring equipment to be used must be sufficiently accurate for the measuring task, easy to handle, robust for use in a machining environment and inexpensive. In the first phase, a DBB measuring system with an extended measuring range was developed, the prerequisites for the synchronised acquisition of the data of the measuring system and the actual axis values of the test machines were created and the fundamentals of the generation of error-sensitive spatial measuring paths were worked out. The aim of the second phase is to increase the spatial path accuracy by identifying and correcting kinematic errors from the measurement data.