Precision of kinematic coupling mechanism for optical instruments

Yuan, Ye; Chen, Liheng; Yang, Le; Dong, Junping; Xu, Shuyan; Wang, Shuxin

doi:10.1016/j.ijleo.2019.163592

Cited by 6 publications

(4 citation statements)

References 11 publications

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“…The contact region of kinematic couplings is small, which results in a huge local stress. Therefore, kinematic couplings are frequently applied in low-load working conditions [ 7 , 8 , 9 , 10 , 11 ]. In the M3S, the coupling bears approximately 4.2 tons of loads without inducing a bending moment to the M3CA.…”

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

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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.

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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

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“…Through years of research, factors such as elastic deformation, friction, and wear within the contact region have been definitively identified as significant influences on the repetitive positioning accuracy of kinematic couplings (Rothenhofer et al,2013;Hale et al,1998;Sun et al,2019;Yuan et al,2023). Ye et al (Ye et al,2020) considered the deformation of the force region in optical instruments and established an expression for calculating kinematic couplings errors. Benedictis et al (Benedictis et al,2023) proposed an analytical method for calculating stress and deflection at the spherical groove contact, using it to compute positioning errors induced by elastic deformation under various loading conditions.…”

Section: Introductionmentioning

confidence: 99%

Optimization Design of Kinematic Couplings for Improving Repetitive Positioning Accuracy of Opto-mechanical Assemblies

Fan,

Yang,

Yuan

et al. 2023

Preprint

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Kinematic coupling, as an efficient form of connection, is frequently employed for the repeated assembly and accurate positioning of replaceable opto-mechanical assemblies within high-power solid-state laser systems. During the kinematic coupling process, uncertainties in the mechanical behavior within the contact region often hinder the attainment of consistent positioning accuracy, potentially leading to an inability to meet operational requirements. This study aims to enhance the repetitive positioning precision of opto-mechanical assemblies kinematic couplings. To achieve this goal, a predictive model for repetitive positioning accuracy is established, accounting for uncertainties in contact region forces. Based on this model, an optimization design of kinematic couplings is conducted to mitigate these challenges. Initially, accounting for uncertainties in mechanical parameters within the contact region, we formulate a static analysis computational model to elucidate the probabilistic distribution of these parameters. Subsequently, employing Hertz contact theory and Holm-Archard wear theory, we quantify the elastic deformation and equivalent wear for each contact region through the calculation of normal pressures. Building upon this foundation, we establish a predictive model for repetitive positioning accuracy. Finally, optimization design is carried out on the friction coefficient of contact surfaces and the structural dimensions of positioning elements. The proposed optimization design is validated through experimental verification. The findings demonstrate that optimization of structural dimensions and contact surface friction coefficients resulted in enhanced repetitive positioning accuracy of 35.9%, effectively ameliorating the assembly quality. This study contributes a quantifiable analytical approach to the prediction and optimization design of repetitive positioning accuracy in kinematic couplings.

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“…Takagi K., Tanaka H. and Ishimura K. [13] studied the effects of pressing order and load on the repeatability of the coupling and obtained the optimal load exerting strategy. Recently, Yuan Y. et al [14] designed a kinematic coupling mechanism and computed its accuracy by homogeneous transformation matrices. In the aforementioned studies, the well-appraised screw theory and Lie group theory were partly used to establish the error model and the efficiency of the methods were proved.…”

Section: Introductionmentioning

confidence: 99%

Repeatability Analysis of Overconstrained Kinematic Coupling Using a Parallel-Mechanism-Equivalent Model

Jian

Liu²,

wang

2020

Preprint

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A novel method for repeatability analysis of overconstrained kinematic coupling using a parallel-mechanism-equivalent-model is proposed. An overconstrained Kelvin-type coupling with one additional support is introduced and used for method illustration. Contact forces of the overconstrained coupling under preload are computed with Moore-Penrose inverse and the deformations are obtained using the Hertz theory. The couping is equivalently modeled as a 7-SPS parallel mechanism, spherical joints of which represent the centers of the supporting balls and the contact points, respectively, and prismatic joints are used to simulate the deformations. Therefore, pose error of the coupling arisen from preload is analyzed using the well-appraised incremental method for forward kinematics analysis of parallel mechanisms. The uncertainties of the preload are discussed and a boundary-sampling method is proposed for repeatability analysis. The main contribution of this study lies in that the proposed parallel-mechanism-equivalent-model and the boundary-sampling method greatly simplify the repeatability analysis of overconstrained kinematic couplings. Finally, the proposed methods are validated by case study.

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Precision of kinematic coupling mechanism for optical instruments

Cited by 6 publications

References 11 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

Optimization Design of Kinematic Couplings for Improving Repetitive Positioning Accuracy of Opto-mechanical Assemblies

Repeatability Analysis of Overconstrained Kinematic Coupling Using a Parallel-Mechanism-Equivalent Model

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