Opt Express. 2022 Dec 5;30(25):44741-44768. doi: 10.1364/OE.474959.
The 6-DOF industrial robot has wide application prospects in the field of optical manufacturing because of its high degrees of freedom, low cost, and high space utilisation. However, the low trajectory accuracy of robots will affect the manufacturing accuracy of optical components when the robots and magnetorheological finishing (MRF) are combined. In this study, aiming at the problem of the diversity of trajectory error sources of robot-MRF, a continuous high-precision spatial dynamic trajectory error measurement system was established to measure the trajectory error accurately, and a step-by-step and multistage iterations trajectory error compensation method based on spatial similarity was established to obtain a high-precision trajectory. The experimental results show that compared with the common model calibration method and general non-model calibration method, this trajectory error compensation method can achieve accurate compensation of the trajectory error of the robot-MRF, and the trajectory accuracy of the Z-axis is improved from PV > 0.2 mm to PV < 0.1 mm. Furthermore, the finishing accuracy of the plane mirror from 0.066λ to 0.016λ RMS and the finishing accuracy of the spherical mirror from 0.184λ RMS to 0.013λ RMS using the compensated robot-MRF prove that the robot-MRF has the ability of high-precision polishing. This promotes the application of industrial robots in the field of optical manufacturing and lays the foundation for intelligent optical manufacturing.
六自由度工业机器人具有自由度高、成本低、空间利用率高等优点，在光学制造领域具有广泛的应用前景。然而，机器人与磁流变抛光（MRF）结合时，机器人的轨迹精度较低会影响光学元件的制造精度。针对机器人-MRF 轨迹误差源多样性的问题，本研究建立了连续高精度空间动态轨迹误差测量系统，以准确测量轨迹误差，并建立了基于空间相似性的分步多级迭代轨迹误差补偿方法，以获得高精度轨迹。实验结果表明，与常见的模型校准方法和通用的非模型校准方法相比，该轨迹误差补偿方法能够实现机器人-MRF 轨迹误差的精确补偿，使 Z 轴轨迹精度从 PV>0.2mm 提高到 PV<0.1mm。此外，使用补偿后的机器人-MRF 对平面反射镜的抛光精度从 0.066λ RMS 提高到 0.016λ RMS，对球面反射镜的抛光精度从 0.184λ RMS 提高到 0.013λ RMS，证明了机器人-MRF 具有高精度抛光能力。这推动了工业机器人在光学制造领域的应用，并为智能光学制造奠定了基础。
