Ultra-precision manufacturing is essential to the production of workpieces of the highest quality in terms of form accuracy, surface accuracy, and integrity. Compared with physical and chemical material removal methods, it has the advantages of high efficiency, high flexibility, and low cost. Because of the direct interaction between the workpiece and the tool during the process of ultra-precision manufacturing, the geometrical parameters of the tool directly affect the surface quality of the workpiece and need to be measured accurately and comprehensively. However, due to the large surface slopes of some tools, some three-dimensional measurement methods cannot measure their geometrical parameters because of limited maximum measurement angle. In this work, we build a focus variation system to make three-dimensional measurements of tools and extract their geometrical parameters. The data processing procedures and the selection of experimental parameters are analyzed in detail using simulations and experiments. Furthermore, we use a step height standard to verify the high accuracy of the measurement system and a roughened flat surface to evaluate the measurement noise and vertical resolution. Measurements of the parameters of a round nose cutting tool and the surface texture parameters of a grinding tool are conducted and indicate that the focus variation system is suitable for measuring the geometrical parameters of tools for ultra-precision manufacturing.

就形状精度，表面精度和完整性而言，超精密制造对于生产最高质量的工件至关重要。与物理化学材料去除方法相比，具有效率高，柔韧性好，成本低的优点。由于在超精密制造过程中工件与刀具之间的直接相互作用，因此刀具的几何参数直接影响工件的表面质量，需要进行准确，全面的测量。但是，由于某些工具的表面坡度较大，某些三维测量方法由于最大测量角度有限而无法测量其几何参数。在这项工作中 我们建立了一个焦点变化系统来对工具进行三维测量并提取其几何参数。使用模拟和实验详细分析了数据处理程序和实验参数的选择。此外，我们使用台阶高度标准来验证测量系统的高精度，并使用粗糙的平坦表面来评估测量噪声和垂直分辨率。进行了圆头切削工具的参数和磨削工具的表面纹理参数的测量，结果表明焦点变化系统适用于测量超精密制造工具的几何参数。使用模拟和实验详细分析了数据处理程序和实验参数的选择。此外，我们使用台阶高度标准来验证测量系统的高精度，并使用粗糙的平坦表面来评估测量噪声和垂直分辨率。进行了圆头切削工具的参数和磨削工具的表面纹理参数的测量，结果表明焦点变化系统适用于测量超精密制造工具的几何参数。使用模拟和实验详细分析了数据处理程序和实验参数的选择。此外，我们使用台阶高度标准来验证测量系统的高精度，并使用粗糙的平坦表面来评估测量噪声和垂直分辨率。进行了圆头切削工具的参数和磨削工具的表面纹理参数的测量，结果表明焦点变化系统适用于测量超精密制造工具的几何参数。