Modelling of time-variant material removal functions for abrasive subaperture polishing

磨料子孔径抛光时变材料去除函数的建模

• 批准号: 387743003
• 负责人: Dr.-Ing. Oltmann Riemer
• 金额: --
• 依托单位: Abteilung Fertigungstechnik
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2018
• 资助国家: 德国
• 起止时间: 2017-12-31 至 2022-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/387743003?language=en
• 关键词: Modelling; time; variant; material; removal

The objective of this project is the development of time-variant material removal functions for abrasive subaperture polishing for the machining of optics and precision parts. This will enable a targeted shape correction with minimal material removal and increase the achievable production accuracy and process reliability. Previous approaches focus on time-consistent material removal functions based on the Preston equation. Although this dwell time controlled removal functions allow a process time saving of up to 35%, they have the disadvantage of an inevitable basic removal, meaning that material has to be removed in any case. In order to remove no material, the polishing tool would theoretically have to be moved infinitely fast over the workpiece. A time-variant removal function allows minimizing or even avoiding this basic removal, which in turn leads to a reduction of process time. For the development of such a removal function, the modeling of a novel polishing algorithm or process control is necessary. Therefore, the material removal must be quantified first, according to significant process parameters such as pressure, nominal removal depth and relative speed. On the basis of these experimental results, specific removal functions will be derived, which are proven by modeling. The underlying model is also based on the Preston approach. However, it is extended by temporally variable terms and thus a time-variant removal function is generated. Main focus is the model description of the variable polishing pressure as well as the variable relative speed. The wear of the polishing tool will also be integrated into the model, since wear also depicts a change in the removal function over time. Part of the modeling will consist in minimizing the deviation between the desired and the actual material removal, i.e. the deviation between the desired and the actual surface. This optimization task will provide the optimal parameter constellation for the individual case. Due to the short computing times, at first a two-dimensional model will be evolved, before a substantially more complex, applicable three-dimensional model is derived.

该项目的目的是开发时间变化的材料去除函数，用于用于加工光学和精密零件的磨料子施加抛光。这将通过最小的材料去除，并提高可实现的生产准确性和过程可靠性，从而实现目标形状校正。先前的方法着重于基于普雷斯顿方程的时遇到的材料去除函数。尽管此停留时间控制的删除功能允许节省多达35％的过程时间，但它们的缺点是不可避免的基本删除，这意味着无论如何都必须去除材料。为了不清除材料，理论上必须在工件上无限地移动抛光工具。时间变化的删除功能可以最大程度地减少甚至避免这种基本去除，从而导致过程时间减少。为了开发这种去除函数，需要建模新型抛光算法或过程控制。因此，必须首先根据大量的过程参数（例如压力，标称去除深度和相对速度）对材料去除进行量化。根据这些实验结果，将得出特定的去除函数，这是通过建模证明的。基础模型也基于Preston方法。但是，它是通过时间变量项扩展的，因此生成了时间变化的删除函数。主要重点是可变抛光压力以及可变相对速度的模型描述。抛光工具的磨损也将集成到模型中，因为磨损还描绘了随着时间的推移的拆卸功能的变化。模型的一部分将包括最大程度地减少所需物质去除和实际材料之间的偏差，即所需的表面与实际表面之间的偏差。此优化任务将为各个情况提供最佳参数星座。由于计算时间短，首先将进化一个二维模型，然后在得出一个更复杂，适用的三维模型之前。