Design of a pure rotation micropositioning stage with dual-range

2022 ◽  
Vol 169 ◽  
pp. 104631
Author(s):  
Juncang Zhang ◽  
Jinqiang Gan ◽  
Huafeng Ding ◽  
Hai Li
Keyword(s):  
1983 ◽  
Vol 61 (10) ◽  
pp. 1462-1473 ◽  
Author(s):  
J.-M. Flaud ◽  
C. Camy-Peyret ◽  
J. W. C. Johns

The pure rotation spectrum of hydrogen sulfide has been recorded between 50 and 320 cm−1 with a Fourier transform spectrometer at an apodized resolution of 0.005 cm−1. This high resolution and a good signal-to-noise ratio lead to a significant improvement in the accuracy of the wavenumbers of the rotational transitions of the three isotopic species [Formula: see text], [Formula: see text], and [Formula: see text] that were observed in natural abundance. These rotational transitions, together with the available microwave data, have been included in a least squares fit leading to the determination of precise rotational constants for each isotopic species. Finally, these constants have been used to calculate precisely the absorption of natural hydrogen sulfide in the far-infrared region of the spectrum.


2021 ◽  
pp. 1-11
Author(s):  
Revanth Damerla ◽  
Shorya Awtar

Abstract This paper presents a systematic constraint-based analysis of the performance attributes of eight parallel kinematic articulated wrist mechanisms from the existing literature. These performance attributes include the number, nature (i.e. pure rotation, or translation, or a combination), and location of a mechanism's Degrees of Freedom (DoFs) in the nominal and displaced configurations, load transmission capability along these DoFs, and load bearing capability along the constraint directions. This systematic analysis reveals performance tradeoffs between these performance attributes for a given mechanism, as well as design tradeoffs across these mechanisms. This analysis also helps inform the suitability of a given mechanism for specific applications.


1956 ◽  
Vol 34 (11) ◽  
pp. 1119-1125 ◽  
Author(s):  
Robert Herman ◽  
Robert J. Rubin

The magnitude of the effect of the vibration–rotation interaction on the intensities of pure rotation lines of diatomic molecules has been calculated for two different molecular models, the anharmonic oscillator and the rotating Morse or Pekeris oscillator. The intensity correction for the anharmonic oscillator has been obtained by adapting the contact transformation formalism for calculating second-order corrections to the energy to the calculation of first-order corrections to the matrix elements of the electric moment as suggested by H. H. Nielsen. The correction to the line intensity for vibrationless transitions of the anharmonic oscillator is found to be[Formula: see text]The results obtained here are also in complete agreement, to first order, with the results obtained earlier by Herman and Wallis for the 1–0 and 2–0 vibration–rotation line intensities. In the case of the Pekeris or rotating Morse oscillator the correction to the pure rotation line intensity is of the same form as above, namely,[Formula: see text]but exhibits minor differences which can be explained in terms of the difference in the vibrational potential energy function in the two cases.


Author(s):  
Ahmed Hachem Chebbi ◽  
Vincenzo Parenti-Castelli

The 3-UPU three degrees of freedom fully parallel manipulator, where U and P are for universal and prismatic pair respectively, is a very well known manipulator that can provide the platform with three degrees of freedom of pure translation, pure rotation or mixed translation and rotation according to the relative directions of the revolute axes. Many studies have been reported in the literature on singularities, workspace and joint clearance influence on the platform accuracy of this manipulator. However, much work has still to be done to reveal all the features this topology can offer to the designer. This paper collects the previous most relevant work done on the 3-UPU parallel manipulator and shows the main results in a coherent general frame. The paper proposes new architectures of the 3-UPU manipulator which offer interesting features to the designer. Finally, based on a number of indexes, a procedure is proposed that allows the designer to select the best architecture of the 3-UPU manipulator for a given task.


1984 ◽  
Vol 282 ◽  
pp. 330 ◽  
Author(s):  
A. J. Sauval ◽  
N. Grevesse ◽  
R. Zander ◽  
J. W. Brault ◽  
G. M. Stokes

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