4m口径SiC反射镜原位检测用静压支撑系统
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摘要
研制了一套用于4m SiC反射镜原位检测的静压支撑系统,以降低超大口径SiC反射镜离线检测的风险,提高其制造效率。首先,推导了单元刚度的解析式,确定了其中关键因素;然后,对支撑单元进行抽样测试,结合解析式预测了支撑群组中单元的工作刚度。最后,通过密封性测试和反射镜原位检测,验证了支撑系统的稳定性;通过有限元模拟,计算了系统的重力卸载面形精度。结果表明:5个单元连组时,单元刚度约为1.9kN/mm,刚度值分布在±3%误差区间;独立单元刚度可高至15kN/mm;3种分组单元刚度预测值分别为1.7,1.1和0.8kN/mm。支撑系统空载时管路压强变化缓慢,表明密封性良好;用该系统支撑4m反射镜时,11天内高度绝对变化量小于50μm,相对变化量小于20μm。54个单元刚度随机分布时,镜面面形高阶残差(RMS)为20nm。提出的系统基本满足原位检测的稳定性和精度要求。
A set of hydrostatic support system for a 4m SiC mirror in-situ testing was designed to reduce the risk of ultra-large mirror off-line testing and to improve fabrication efficiency.Firstly,the analytical formula for calculating support stiffness was derived,and its main factor was found.Then,some support samples were tested,and the support stiffness of a single support unit in different groups was predicted by combining the sample results and analytical formula.Finally,the stability of the support system was evaluated by pressurization test and in-situ testing,and the mirror surface precision with its gravity offloaded by the support system was calculated by finite element simulation.Results show that the average stiffness is about 1.9kN/mm with a relative difference among support units about 3% when 5 units are linked together,the stiffness for a single unit isolated is as high as 15kN/mm,and 3 kinds of unit stiffness in the support system are 1.7,1.1 and 0.8kN/mm respectively.Moreover,pressurization test shows a slow pressure change,which indicates that the system is well sealed.When the hydrostatic system was used for a 4m mirror,the height changes rise up and down within 50μm in 11 days,and the relative change is less than 20μm.When the mirror is supported on 54 units with stiffness difference by 3% randomly,the surface RMS is less than 20 nm.The proposed system meets the requirement of in-situ optical testing for precision and stability.
A set of hydrostatic support system for a 4m SiC mirror in-situ testing was designed to reduce the risk of ultra-large mirror off-line testing and to improve fabrication efficiency.Firstly,the analytical formula for calculating support stiffness was derived,and its main factor was found.Then,some support samples were tested,and the support stiffness of a single support unit in different groups was predicted by combining the sample results and analytical formula.Finally,the stability of the support system was evaluated by pressurization test and in-situ testing,and the mirror surface precision with its gravity offloaded by the support system was calculated by finite element simulation.Results show that the average stiffness is about 1.9kN/mm with a relative difference among support units about 3% when 5 units are linked together,the stiffness for a single unit isolated is as high as 15kN/mm,and 3 kinds of unit stiffness in the support system are 1.7,1.1 and 0.8kN/mm respectively.Moreover,pressurization test shows a slow pressure change,which indicates that the system is well sealed.When the hydrostatic system was used for a 4m mirror,the height changes rise up and down within 50μm in 11 days,and the relative change is less than 20μm.When the mirror is supported on 54 units with stiffness difference by 3% randomly,the surface RMS is less than 20 nm.The proposed system meets the requirement of in-situ optical testing for precision and stability.
引文
[1]赵文兴,张舸.特大尺寸轻型碳化硅镜坯烧结工艺研究[J].硅酸盐通报,2014,33(11):2838-2842.ZHAO W X,ZHANG G.Study on sintering process of ultra-large-scale lightweight SiC mirror blank[J].Bulletin of the Chinese Ceramic Society,2014,33(11):2838-2842.(in Chinese)
[2]张学军,李志来,张忠玉.基于SiC材料的空间相机非球面反射镜结构设计[J].红外与激光工程,2007,36(5):577-582.ZHANG X J,LI ZH L,ZHANG ZH Y.Space telecope aspherical mirror structure design based on SiC material[J].Infrared and Laser Engineering,2007,36(5):577-582.(in Chinese)
[3]SEIN E,TOULEMONT Y,SAFA F,et al..Aφ3.5mdiameter SiC telescope for Herschel mission[J].SPIE,2003,4850:606-618.
[4]ZHANG G,ZHAO W X,ZHAO R C,et al..Fabricating large-scale mirrors using reaction-bonded silicon carbide[EB/OL].SPIE Newsroom,http://spie.org/newsroom/6582-fabricating-large-scale-mirrors-usingreaction-bonded-silicon-carbide?ArticleID=x119942&highlight=x2422.(2016-08-09).
[5]LAN B,WU X X,LI J F,et al..Influence of axial-force errors on the deformation of the 4mlightweight mirror and its correction[J].Applied Optics,2017,56(3):611-619.
[6]吴小霞,李剑锋,宋淑梅,等.4mSiC轻量化主镜的主动支撑系统[J].光学精密工程,2014,22(9):2451-2457.WU X X,LI J F,SONG S M,et al..Active support system for 4mSiC lightweight primary mirror[J].Opt.Precision Eng.,2014,22(9):2451-2457.(in Chinese)
[7]李剑锋,吴小霞,邵亮.大口径SiC主镜主动支撑研究及促动器设计[J].红外与激光工程,2016,45(7):0718003.LI J F,WU X X,SHAO L.Study on active support for large SiC primary mirror and force actuator design[J].Infrared and Laser Engineering,2016,45(7):0718003.(in Chinese)
[8]刘振宇,李龙响,曾雪峰,等.大口径非球面反射镜误差分离组合加工技术[J].光学精密工程,2017,25(4):813-819.LIU ZH Y,LI L X,ZENG X F,et al..Fabrication of large aspheric mirror using multi-mode polishing based on error separation[J].Opt.Precision Eng.,2017,25(4):813-819.(in Chinese)
[9]徐宏,关英俊.空间相机1m口径反射镜组件结构设计[J].光学精密工程,2013,21(6):1488-1495.XU H,GUAN Y J.Structural design of 1mdiameter space mirror component of space camera[J].Opt.Precision Eng.,2013,21(6):1488-1495.(in Chinese)
[10]胡海飞,罗霄,辛宏伟,等.超大口径光学制造均力支撑布局优化[J].光学学报,2014,34(4):0422003.HU H F,LUO X,XIN H W,et al..Layout optimization of equal-force supports for ultra-large optical fabrication[J].Acta Optica Sinica,2014,34(4):0422003.(in Chinese)
[11]胡海飞,罗霄,戚二辉,等.超大口径光学制造的静压支撑系统集成与控制[J].光学学报,2015,35(8):0822001.HU H F,LUO X,QI E H,et al..System integration and control of the hydrostatic supports for manufacturing ultra-large optics[J].Acta Optica Sinica,2015,35(8):0822001.(in Chinese)
[12]李剑锋.望远镜主镜支撑用液压缸研究与设计[J].长春理工大学学报:自然科学版,2014,37(3):32-37.LI J F.Research and design of cylinder used as the primary mirror support of telescope[J].Journal of Changchun University of Science and Technology:Natural Science Edition,2014,37(3):32-37.(in Chinese)
[13]XIONG L,LUO X,LIU Z Y,et al..Swing arm profilometer:analytical solutions of misalignment errors for testing axisymmetric optics[J].Optical Engineering,2016,55(7):074108.
[2]张学军,李志来,张忠玉.基于SiC材料的空间相机非球面反射镜结构设计[J].红外与激光工程,2007,36(5):577-582.ZHANG X J,LI ZH L,ZHANG ZH Y.Space telecope aspherical mirror structure design based on SiC material[J].Infrared and Laser Engineering,2007,36(5):577-582.(in Chinese)
[3]SEIN E,TOULEMONT Y,SAFA F,et al..Aφ3.5mdiameter SiC telescope for Herschel mission[J].SPIE,2003,4850:606-618.
[4]ZHANG G,ZHAO W X,ZHAO R C,et al..Fabricating large-scale mirrors using reaction-bonded silicon carbide[EB/OL].SPIE Newsroom,http://spie.org/newsroom/6582-fabricating-large-scale-mirrors-usingreaction-bonded-silicon-carbide?ArticleID=x119942&highlight=x2422.(2016-08-09).
[5]LAN B,WU X X,LI J F,et al..Influence of axial-force errors on the deformation of the 4mlightweight mirror and its correction[J].Applied Optics,2017,56(3):611-619.
[6]吴小霞,李剑锋,宋淑梅,等.4mSiC轻量化主镜的主动支撑系统[J].光学精密工程,2014,22(9):2451-2457.WU X X,LI J F,SONG S M,et al..Active support system for 4mSiC lightweight primary mirror[J].Opt.Precision Eng.,2014,22(9):2451-2457.(in Chinese)
[7]李剑锋,吴小霞,邵亮.大口径SiC主镜主动支撑研究及促动器设计[J].红外与激光工程,2016,45(7):0718003.LI J F,WU X X,SHAO L.Study on active support for large SiC primary mirror and force actuator design[J].Infrared and Laser Engineering,2016,45(7):0718003.(in Chinese)
[8]刘振宇,李龙响,曾雪峰,等.大口径非球面反射镜误差分离组合加工技术[J].光学精密工程,2017,25(4):813-819.LIU ZH Y,LI L X,ZENG X F,et al..Fabrication of large aspheric mirror using multi-mode polishing based on error separation[J].Opt.Precision Eng.,2017,25(4):813-819.(in Chinese)
[9]徐宏,关英俊.空间相机1m口径反射镜组件结构设计[J].光学精密工程,2013,21(6):1488-1495.XU H,GUAN Y J.Structural design of 1mdiameter space mirror component of space camera[J].Opt.Precision Eng.,2013,21(6):1488-1495.(in Chinese)
[10]胡海飞,罗霄,辛宏伟,等.超大口径光学制造均力支撑布局优化[J].光学学报,2014,34(4):0422003.HU H F,LUO X,XIN H W,et al..Layout optimization of equal-force supports for ultra-large optical fabrication[J].Acta Optica Sinica,2014,34(4):0422003.(in Chinese)
[11]胡海飞,罗霄,戚二辉,等.超大口径光学制造的静压支撑系统集成与控制[J].光学学报,2015,35(8):0822001.HU H F,LUO X,QI E H,et al..System integration and control of the hydrostatic supports for manufacturing ultra-large optics[J].Acta Optica Sinica,2015,35(8):0822001.(in Chinese)
[12]李剑锋.望远镜主镜支撑用液压缸研究与设计[J].长春理工大学学报:自然科学版,2014,37(3):32-37.LI J F.Research and design of cylinder used as the primary mirror support of telescope[J].Journal of Changchun University of Science and Technology:Natural Science Edition,2014,37(3):32-37.(in Chinese)
[13]XIONG L,LUO X,LIU Z Y,et al..Swing arm profilometer:analytical solutions of misalignment errors for testing axisymmetric optics[J].Optical Engineering,2016,55(7):074108.