High precision machining in TMT (Thirty Meter Telescope) structure manufacturing

Kamikawa, Kenji; Nagai, Akihiro; Ashida, T.; Tani, Kazuhiko; Nariyama, Tatsuya; Ishida, Takayuki; Takaki, Junji; Kawaguchi, Noboru; Endo, Mamoru; Ezaki, Yutaka; Usuda, Tomonori; Saito, Masao

doi:10.1117/12.2560614

Cited by 3 publications

(2 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The Thirty Meter Telescope (TMT) is a typical Ritchey–Chrétien optical system, in which all active instruments work on Nasmyth platforms, and is designed to transmit light from 310 to 28,000 nm. However, to relay the optical beams from the secondary mirror to the active instruments of the TMT, the Giant Steerable Science Mirror (GSSM) has been proposed [ 1 , 2 , 3 ]. This is significantly different from other large telescopes, such as GMT, LAMOST [ 4 ], and E-ELT [ 5 ].…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Semi-Kinematic Coupling Design and Analysis for Giant Steerable Science Mirror Prototype of Thirty Meter Telescope

Zhao,

Chen,

et al. 2024

Sensors

View full text Add to dashboard Cite

The Giant Steerable Science Mirror prototype is being developed to assess the tertiary mirror system of the Thirty Meter Telescope. In this study, a new semi-kinematic coupling design is proposed for the prototype based on three pairs of V-grooves and canoe-like components to allow for high repeatability accuracy under heavy loads. A mathematical model was constructed to estimate the repeatability accuracy using the corresponding measurement results and machining errors. The proposed design was verified by an experiment, and the results were consistent with the mathematical model. Furthermore, the results indicate that the repeatability of the semi-kinematic coupling is sufficient for the requirement.

show abstract

Section: Introductionmentioning

confidence: 99%

“…However, a kinematic coupling could effectively reduce the maintenance cycle of the M3CA. Due to the fact that the tertiary mirror is a flat oval mirror with a major diameter of 4 m, the out-of-plane error needs to be strictly controlled, as it has a significant influence on the telescope [ 3 ].…”

Section: Introductionmentioning

confidence: 99%

Semi-Kinematic Coupling Design and Analysis for Giant Steerable Science Mirror Prototype of Thirty Meter Telescope

Zhao,

Chen,

et al. 2024

Sensors

View full text Add to dashboard Cite

show abstract

High-precision magnetorheological finishing based on robot by measuring and compensating trajectory error

Cheng¹,

Li²,

Li³

et al. 2022

Opt. Express

View full text Add to dashboard Cite

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.

show abstract

Accurately predicting the tool influence function to achieve high-precision magnetorheological finishing using robots

Cheng,

Li,

Xue

et al. 2023

Opt. Express

View full text Add to dashboard Cite

Industrial robots with six degrees-of-freedom have significant potential for use in optical manufacturing owing to their flexibility, low cost, and high space utilisation. However, the low trajectory accuracy of robots affects the manufacturing accuracy of optical components when combined with magnetorheological finishing (MRF). Moreover, general robot trajectory-error compensation methods cannot compensate for the running errors of large robots with high precision. To address this problem, a three-dimensional (3D) tool influence function (TIF) model based on inverse distance interpolation is developed in this study to accurately predict the TIF of different polishing gaps. A high-precision robot-MRF polishing strategy based on variable TIFs and surface shape accuracy of polished optics is proposed to achieve high-precision manufacturing without compensating for trajectory errors. Subsequently, the accuracy of a ϕ420 mm fused silica mirror is experimentally verified to be from 0.11 λ RMS to 0.013 λ RMS. This validates that the robot-MRF can achieve high-precision polishing without compensating for trajectory errors. Furthermore, the proposed model will promote the applications of industrial robots in optical manufacturing and will serve as a reference in the field of intelligent optical manufacturing.

show abstract

High precision machining in TMT (Thirty Meter Telescope) structure manufacturing

Cited by 3 publications

References 0 publications

Semi-Kinematic Coupling Design and Analysis for Giant Steerable Science Mirror Prototype of Thirty Meter Telescope

Semi-Kinematic Coupling Design and Analysis for Giant Steerable Science Mirror Prototype of Thirty Meter Telescope

High-precision magnetorheological finishing based on robot by measuring and compensating trajectory error

Accurately predicting the tool influence function to achieve high-precision magnetorheological finishing using robots

Contact Info

Product

Resources

About