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Session Chair: Xuejun Zhang, Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences, People\'s Republic of China
Location:Room 21 (ICM, 2nd Floor)
8:30 - 8:45 ID: 121 / S05: 1 Manufacturing, Tolerancing, and Testing of Optical Systems (MOS)
Effect of Pad Elastic Modulus on The Polishing Induced Plastic Subsurface Damages Distribution of Fused Silica Optics
Xiang He, Chao Cai, Ping Ma
ChengDu Fine Optical Engineering Research Center, China, People's Republic of
The plastic subsurface damages distribution of fused silica optics polished with different pads are investigated. The elastic interaction model, plastic indentation model and wear relationships are combined together to theoretically characterize the plastic subsurface damages distribution in different polishing processes, which shows consistent results with experiments. It reveals that most of the polishing induced subsurface damages are plastic damages. A few largest polishing particles in the tail end distribution mainly decide the final depth distribution and density of the polishing induced plastic subsurface damages. The larger pad elastic modulus will make the few largest polishing particles bear much larger load and generate larger proportion of observable plastic subsurface damages. Using polishing pad with lower elastic modulus is prominent for restricting the generation of fractures and plastic damages.
8:45 - 9:00 ID: 148 / S05: 2 Manufacturing, Tolerancing, and Testing of Optical Systems (MOS)
Machine Learning Robot Polishing Cell
Max Schneckenburger, Luis Garcia, Rainer Boerret
Aalen University, Germany
The quality of optical components such as lenses or mirrors can be described by shape errors and surface roughness. The stability of the polishing process becomes more and more important. Parameters such as chemical stability of the slurry or tool wear are key elements for a deterministic computer controlled polishing process. Aim of this work is to monitor many process-relevant parameters by using sensors attached to the polishing head and to the polishing process. Examples are a rpm and a torque sensor mounted close to the polishing pad, a vibration sensor for the oszillation bearings, as well as a tilt sensor and a force sensor for measuring the polishing pressure. By means of a machine learning system, predictions of tool wear and the related surface quality shall be made. Goal is the detection of the critical influence factors during the polishing process and to have a kind of predictive maintenance system for tool path planning and for tool change intervals.
9:00 - 9:15 ID: 152 / S05: 3 Manufacturing, Tolerancing, and Testing of Optical Systems (MOS)
Steel Mould Surface Improvement By Robot Fluid Jet Polishing And Robot Pad Polishing For Polymer Optic Production
Rui Almeida, Timon Ebert, Rainer Börret, Mario Pohl
Hochschule Aalen, Germany
In order to improve the quality of injection-moulded polymer optic parts, it is necessary to improve the quality of the respective steel moulds. It is not only necessary to improve the surface roughness of the mould, but also its geometrical shape. The material removal obtained from robot pad polishing is too low. This makes a shape correction after the milling step a very prolonged process. The objective is to use a polishing chain to improve the surface quality of steel samples in terms of shape deviation and surface roughness. This correction polishing chain uses the robot fluid jet polishing for the geometrical shape correction and afterwards the robot pad polishing for the improvement of the surface roughness. Due to the high material removal rates of the fluid jet polishing, it is possible to correct the geometrical shape of steel moulds very fast up to a certain deviation. The pad polishing process improves the surface roughness of the steel samples.
9:15 - 9:30 ID: 165 / S05: 4 Manufacturing, Tolerancing, and Testing of Optical Systems (MOS)
Study of Footprint Variations of CCP Considering Machine Kinematics
Guoyu Yu1, Christina Reynolds1, David Walker1,3,4, Oliver Fahnle2
1University of Huddersfied, United Kingdom; 2FISBA AG, Switzerland; 3University College London, United Kingdom; 4Zeeko Ltd, United Kingdom
This paper investigates the differentiation between machine’s static and dynamic footprint (FP). The results have shown progressing footprint variation related to tool’s tilt angle. Continuous tilt angle compensation has been applied to offset this effect.
9:30 - 9:45 ID: 128 / S05: 5 Manufacturing, Tolerancing, and Testing of Optical Systems (MOS)
Surface Figuring of Large Carbon Fiber Reinforced Polymer Antenna Reflector with A Dual-robots Fabrication System
Qiang Xin, Haitao Liu, Jieli Wu, Lin Tang, Dailu Wang, Yongjian Wan
Institute of Optics and Electronics, Chinese Academy of Sciences, People's Republic of China
Carbon Fiber Reinforced Polymer (CFRP) has excellent physical and chemical properties which make it a promising material in making large space borne components, especially in making antenna reflectors and ultra-lightweight space mirrors. These components are usually in large scale to achieve the application requirements. In this research, a dual-robots fabrication system was in-house developed to meet the requirement for figuring a large off-axis parabolic CFRP antenna reflector with the size of 2.4m×4.58m. To make sure that whole surface of the antenna reflector could be covered by the fabrication system, the surface was divided into six regions to accomplish the fabrication. In addition, a special designed tool was utilized to adapt to the curvature variation of the surface. The final surface form accuracies obtained for areas ≤φ1750mm, ≤φ2400mm and the whole surface of the antenna reflector were 13.5μm RMS, 23.4μm RMS and 45.8μm RMS, respectively. Feasibility and surface figuring accuracy of the dual-robots system in fabricating large scale components were verified.