Wang Shixiang, Cheung Chi Fai, Ren Mingjun, Liu Mingyu
Parnter State Key Laboratory of Ultra-Precision Machining Technology, Department of Industrial and Systems Engineering, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong, China.
Robotics Institute, School of Mechanical Engineering, Shanghai Jiao Tong University, Shanghai 200240, China.
Micromachines (Basel). 2018 Jan 30;9(2):52. doi: 10.3390/mi9020052.
Form characterization of a machined optical freeform surface demands accurate alignment of the sampled measured data points on the machined surface, and they are compared with the designed geometry of the surface through positioning. In this paper, a fiducial-aided robust positioning method (FAPM) is developed which attempts to evaluate freeform surfaces with high efficiency and precision. The FAPM method makes use of fiducials as reference datum to form a fiducial-aided computer-aided design (FA-CAD) of the freeform surface which not only establishes an inherent surface feature, but also links the different coordinate systems among design coordinate frame, machine tool, and measurement instrument. To verify the capability of the proposed method, a series of experiments were conducted. Compared with the traditional freeform measurement method (e.g., least squares method), the results indicate that the robustness and accuracy of the measurement is significantly enhanced by the FAPM.
对加工后的光学自由曲面进行形状表征需要精确对准加工表面上采样的测量数据点，并通过定位将它们与表面的设计几何形状进行比较。本文提出了一种基准辅助鲁棒定位方法（FAPM），旨在高效、精确地评估自由曲面。FAPM方法利用基准作为参考基准，形成自由曲面的基准辅助计算机辅助设计（FA-CAD），这不仅建立了固有的表面特征，还连接了设计坐标系、机床和测量仪器之间的不同坐标系。为验证所提方法的能力，进行了一系列实验。与传统的自由曲面测量方法（如最小二乘法）相比，结果表明FAPM显著提高了测量的鲁棒性和准确性。
