{"title":"Initial polishing machine control model to determine target TIF depth on SiC mirror surfaces (Conference Presentation)","authors":"Jeong-Yeol Han, Suyeon Cha, Dohoon Kim, M. Cho","doi":"10.1117/12.2529836","DOIUrl":"https://doi.org/10.1117/12.2529836","url":null,"abstract":"Due to the high toughness of SiC material, in general, the polishing time of a SiC mirror has been challenging to determine by optician. In the optical shop, optician normally enters input parameters into a polishing machine prior to polish out the mirror surface. The target surface removal rate, specified by an optician, are highly depending on polishing schedule. A very tight polishing schedule commonly thrusts adventurous larger target quantities on the optician. However, the target numbers should be determined by the reliability of relationships between the machine input parameter and output removal rate. In this paper, we introduce an initial model which can reliably suggest machine input parameters for polishing head. These parameters can control polishing processes to achieve the target TIF (Tool Influence Function) depth which is an unit polishing removal quantity on the SiC mirror optical surfaces.","PeriodicalId":275868,"journal":{"name":"Material Technologies and Applications to Optics, Structures, Components, and Sub-Systems IV","volume":"69 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131684163","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Optical mirrors design using topology optimization for additive manufacturing (Conference Presentation)","authors":"Nisrine Louh","doi":"10.1117/12.2529515","DOIUrl":"https://doi.org/10.1117/12.2529515","url":null,"abstract":"OPTICAL MIRRORS DESIGN USING TOPOLOGY OPTIMIZATION FOR ADDITIVE MANUFACTURING (ABSTRACT) \u0000Author : Nisrine Louh1\u0000Co-authors : Malorie Villemaire1, Stephanie Behar Lafenetre1, Nicolas Rousselet2, Vincent Costes3\u0000Contact : Nisrine Louh – nisrine.louh@thalesaleniaspace.com \u00001. Thales Alenia Space, 5 Allee des Gabians, 06150 Cannes, France\u00002. 3D Ceram, Limoges\u00003. CNES\u0000\u0000Themes – Mirrors, topology optimization, space structures, additive manufacturing \u0000For scientific satellite, the mirrors are always on the critical path of a project. The design and the sizing of the mirrors are constrained by the mechanical holding, the mass, the cost and the manufacturability. These criteria require numerous compromises and therefore, optical mirrors are designed as early as possible to anticipate the leanings, the manufacturing time and the risks during this manufacture. In this article, we will describe a new method developed to optimize the space optics taking into account the various specifications and using topology optimization. This development is settled in the perimeter of a CNES study named FAME in collaboration with 3DCERAM. The goal is to highlight the feasibility and interest to “print” a telescope mirror. Our objective is to define a way to reduce the weight, to avoid deformation of the optical surface and at the same time to keep a stiffness that allows the structure to withstand the vibration loads.\u0000Moreover, this new approach permits very innovative designs. First, the optimization is made on both the mass and the stiffness. Then, mechanical analyses are performed to verify that the design is viable on the mechanical environment of the mirror. Besides, we verify that the Wavefront Error and the optical performances are compliant with our needs and requirements.\u0000Thales Alenia Space is interested in studying and introducing additive manufacturing in its processes. The advantages and limits of this new technology to “print” complex designs are presented.","PeriodicalId":275868,"journal":{"name":"Material Technologies and Applications to Optics, Structures, Components, and Sub-Systems IV","volume":"30 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122606627","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}