A Transmission Index for Spatial Mechanisms

1973 ◽  
Vol 95 (2) ◽  
pp. 589-597 ◽  
Author(s):  
G. Sutherland ◽  
B. Roth

A general index of the quality of motion transmission for spatial mechanisms is developed using the theory of screws. This index is shown to be related to the mechanical error possible in a linkage. A method for synthesizing spatial linkages with desirable motion transmission and mechanical error characteristics is developed and examples are shown for the RGGR linkage.

Author(s):  
Chao Chen ◽  
Jorge Angeles

This paper proposes a generalized transmission index for spatial mechanisms, based on the transmission index introduced by Sutherland and Roth. This index is more general and welldefined in all the cases; it matches the virtual coefficient between the transmission wrench screw and the output twist screw exactly. A method is developed to compute the transmission wrench screw in spatial single-loop linkages. We illustrate the application of this index in a RSCR linkage.


2021 ◽  
Author(s):  
María Serrano Ruiz

This document presents a case study of acoustic analysis in an open-plan office. Since Mexico does not have a standard for evaluating acoustic conditions in offices, it is relevant to compare different acoustic evaluation methods used for open-plan offices. According to several studies, one of the main acoustic characteristics for open-plan office spaces is speech intelligibility. Therefore, the purpose of this document is to compare psychoacoustic parameters to evaluate speech intelligibility in open-plan offices. We analyzed physical factors as reverberation and speech clarity in different office points, as well as semantic factors based on subjective methods with standardized values of the quality of speech intelligibility. The study was carried out under real open-plan office conditions in a library in a university in northern Mexico. The study factors of interest were type of sound, sound source, and location of the listener, with Reverberation Time (RT), Speech Transmission Index (STI) and Loss of consonant articulation (%ALCons) as the measures of impact on intelligibility. This case study provides additional evidence of the relationship between intelligibility and the position of sound sources; also, it was noted that location of listeners influenced analyzed intelligibility parameters. On the other hand, this case study offers information concerning to use psychoacoustic parameters for subjective classification of quality of the speech intelligibility to evaluate how is background noise perceived in open-plan office users. However, it is noteworthy that this study represents a single office with its own interior and space design characteristics.


2003 ◽  
Vol 16 (8) ◽  
pp. 880-883 ◽  
Author(s):  
Kevin M Harris ◽  
Kevin R Schum ◽  
Thomas Knickelbine ◽  
David G Hurrell ◽  
Jodi L Koehler ◽  
...  

Author(s):  
Frank H. Schaefer

Abstract This paper examines the possibility of a new toothed belt construction to run in various pulley-types. The measurements from a laboratory dynamometer test stand show the belt life under special test conditions by use of HTD-, STPD- and RPP-pulleys, each with an angle of wrap of 180°. In case of locked center distance the increase of torque causes tooth climbing until belt jumping occurs. The pretension was brought into line with the torque each time the torque was increased and the jumping limit torque was determined. From literature it is expected that the results for the behavior of the HTD- and the RPP-pulley are similar. Another parameter to describe the quality of motion is the noise. Here sound power is a very effective descriptor of how noisy an object is. It was determined from sound intensity measurements for HTD- and STPD-pulleys. The ratio of the toothed belt drive used for the noise measurement was 0.63.


2008 ◽  
Vol 23 (5) ◽  
pp. 536-544 ◽  
Author(s):  
Anton E. Bowden ◽  
Heather L. Guerin ◽  
Marta L. Villarraga ◽  
Avinash G. Patwardhan ◽  
Jorge A. Ochoa

1995 ◽  
Author(s):  
Albert A. Deknuydt ◽  
Stefaan Desmet ◽  
Luc Van Eycken ◽  
Andre J. Oosterlinck

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