Polishing Robot Processing Large-diameter Optical Element Key Technology Research

Large telescope is an indispensable tool to explore the universe. For observing further and darker celestial, astronomical telescope aperture increases rapidly. With the upsurge of constructing giant telescope, the demand of large-diameter optical element is also increasing rapidly. The requirements of processing efficiency and processing accuracy about large-aperture optical element are also increasing quickly. There are many processing methods of large-diameter optical element. The common method is Computer Control Optical Surfacing Technology. Industrial robot technology is developing rapidly, and industrial robot has been widely applied in various fields, Industrial robot technology and Computer Control Optical Surfacing Technology combine to form intelligent polishing robot processing technology. Using robot processing optical element has become a development direction of the large aperture optical element. The paper studies polishing robot processing large aperture optics elements key technology with the means of robot. The main work includes the following aspects:1. Measure the robot error, including track location error, polishing disc pressure error and robot extremity moving speed error, and analyze the errors effect on the robot processing results. Give the relationship between different caliber polishing discs and the robot errors.2. Analyze the robot processing technology basic idea by Princeton assumptions and classical CCOS processing theory. According to the characteristics of robot moving, set up the robot partial processing trajectory planning model. Using improved RL deconvolution algorithm calculate the dwell time, and give the transformation model between robot extremity moving speed and the dwell time. For low processing efficiency of large aperture optics element, propose multiple robots combination processing model.3. The paper briefly describes the mechanical structure of the robot and grinding system. Using MATLAB prepare robot processing crafts software, and complete interactive interface by MATLAB_GUI, The module is used to guide the process.4. According to the built robot process model, Carry out grinding experiments on the diameter of 1.2m parabolic mirror. The Surface error converge from PV 1047 um RMS 293 um to the PV 55 um RMS 6um. Demonstrate the effectiveness of robotic machining model.Theoretical analysis and experimental results of this paper have guiding action for the practical application of robot process large aperture optical element.