Analytical analysis and oscillation control of payload twisting dynamics in a tower crane carrying a slender payload

2021 ◽  
Vol 158 ◽  
pp. 107763
Author(s):  
Jiahui Ye ◽  
Jie Huang
2021 ◽  
pp. 107754632110546
Author(s):  
Abdulaziz Al-Fadhli ◽  
Emad Khorshid

This paper presents a smooth command (SC) input shaper for suppressing payload oscillations in rest-to-rest simultaneous radial and tangential motions of a tower crane. The radial and tangential acceleration profiles of the compound motions are represented by multi-sine wave functions with independent and variable maneuvering time. The proposed SC is designed using a nonlinear mathematical model of the tower crane while the parameters of the acceleration profiles and maneuvering times were optimized using a particle swarm algorithm (PSO). The simulated results were verified experimentally on a laboratory scale tower crane. The results confirm that the proposed SC input effectively canceled residual vibrations of the payload compound motions with a time length comparable to zero vibrations (ZV) shaper. Moreover, sensitivity analysis to variations in cable length reveals that the proposed command input is robust over a wide range of cable lengths.


2020 ◽  
Vol 11 (3) ◽  
pp. 80-85
Author(s):  
Bekzod Bobomurodov ◽  
◽  
Dilfuza Akabirxodjayeva

This article has discussed the importance of information and communication technologies for the economy of Uzbekistan and the ongoing reforms in this area. The purpose of the study is to give suggestions and recommendations for the development of ICT in Uzbekistan. In the article, an analytical analysis of employment in the field of ICT has been accomplished.


2013 ◽  
Author(s):  
Jan Reimes ◽  
Marc Lepage ◽  
Frank Kettler ◽  
Jörg Zerlik ◽  
Frank Homann ◽  
...  

2009 ◽  
Vol 45 (4) ◽  
pp. 549-556 ◽  
Author(s):  
K. Lācis ◽  
◽  
A. Muižnieks ◽  
N. Jēkabsons ◽  
A. Rudevičs ◽  
...  

2020 ◽  
Vol 1671 ◽  
pp. 012006
Author(s):  
C A Ramírez ◽  
M Holguin ◽  
E Rivas-Trujillo
Keyword(s):  

Fluids ◽  
2021 ◽  
Vol 6 (4) ◽  
pp. 138
Author(s):  
Ali Rehman ◽  
Zabidin Salleh

This paper analyses the two-dimensional unsteady and incompressible flow of a non-Newtonian hybrid nanofluid over a stretching surface. The nanofluid formulated in the present study is TiO2 + Ag + blood, and TiO2 + blood, where in this combination TiO2 + blood is the base fluid and TiO2 + Ag + blood represents the hybrid nanofluid. The aim of the present research work is to improve the heat transfer ratio because the heat transfer ratio of the hybrid nanofluid is higher than that of the base fluid. The novelty of the recent work is the approximate analytical analysis of the magnetohydrodynamics mixed non-Newtonian hybrid nanofluid over a stretching surface. This type of combination, where TiO2+blood is the base fluid and TiO2 + Ag + blood is the hybrid nanofluid, is studied for the first time in the literature. The fundamental partial differential equations are transformed to a set of nonlinear ordinary differential equations with the guide of some appropriate similarity transformations. The analytical approximate method, namely the optimal homotopy analysis method (OHAM), is used for the approximate analytical solution. The convergence of the OHAM for particular problems is also discussed. The impact of the magnetic parameter, dynamic viscosity parameter, stretching surface parameter and Prandtl number is interpreted through graphs. The skin friction coefficient and Nusselt number are explained in table form. The present work is found to be in very good agreement with those published earlier.


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