Development and investigation of an indirect dynamic force measurement system based on voltage and current signals for cutting technology

用于切割技术的基于电压和电流信号的间接动态力测量系统的开发和研究

• 批准号: 497676155
• 负责人: Professor Dr.-Ing. Thomas Bergs
• 金额: --
• 依托单位: Werkzeugmaschinenlabor - WZL
• 依托单位国家: 德国
• 项目类别: Research Grants
• 资助国家: 德国
• 项目状态: 未结题
• 来源: https://gepris.dfg.de/gepris/projekt/497676155?language=en
• 关键词: Development; investigation; indirect; dynamic; force

Tool load is crucial in the cutting process including milling, and monitoring the process force provides valuable information about the tool condition as well as the machining process itself regarding surface integrity. It enables us to understand/optimize the process toward the enhancement of productivity and quality control. In terms of the investment costs of a dynamometer, the indirect force measurement is desirable for an industrial application. Although many existing methods that use the motor-drive information, e.g., motor current, can monitor the slow (static) change of the process force, they cannot acquire the rapid (dynamic) change. Therefore, a monitoring solution of the process force with a wide measurement frequency-bandwidth is desired especially for the dynamic milling process, on which this project focuses. For this purpose, this project utilizes the voltage and current signals of the motor drive since these signals can be measured with a high sampling speed. In order to indirectly-measure the dynamic force, two characteristics that limit the measurement bandwidth of the existing methods must be considered: the nonlinear friction and the high-order transfer behavior from the process force at the tooltip to the motor current. These characteristics depend on the mechanical structure of the motor drives (direct-driven and ball-screw-driven axes), and this project solves these two difficulties of both types of drive mechanisms to indirectly-measure each process torque/force acting on the spindle/feed axes. Here, each drive axis is supposed to have its own measurement accuracy and bandwidth. This project then fuses the torque and forces based on the online identification of the coefficients of a mechanistic force model that is a function of the current cutting (engagement) conditions so that the overall measurement performance is enhanced. In this project, not only the establishment of the monitoring methodology but also an investigation of the measurement accuracy under different cutting conditions are to be handled.

刀具载荷在包括铣削在内的切削过程中至关重要，监控过程力可提供有关刀具状态以及加工过程本身的表面完整性的有价值信息。它使我们能够了解/优化流程，以提高生产力和质量控制。就测力计的投资成本而言，间接力测量对于工业应用是理想的。虽然许多使用电动机驱动信息的现有方法，例如，电机电流，可以监测过程力的缓慢（静态）变化，它们不能获得快速（动态）变化。因此，需要一种具有宽测量频带的过程力监测解决方案，特别是对于动态铣削过程，这是本项目的重点。为此，该项目利用电机驱动器的电压和电流信号，因为这些信号可以以高采样速度测量。为了间接测量动态力，必须考虑限制现有方法测量带宽的两个特性：非线性摩擦和从工具尖端处的过程力到电机电流的高阶传递行为。这些特性取决于电机驱动器的机械结构（直接驱动和滚珠丝杠驱动轴），本项目解决了这两种类型的驱动机构的这两个困难，以间接测量作用在主轴/进给轴上的每个过程扭矩/力。这里，每个驱动轴都应该有自己的测量精度和带宽。该项目然后基于机械力模型的系数的在线识别来融合扭矩和力，该机械力模型是当前切割（接合）条件的函数，从而增强整体测量性能。在这个项目中，不仅要建立监测方法，而且要调查不同切削条件下的测量精度。