Raja Jarray¹, Mujahed Al-Dhaifallah^2,*, Hegazy Rezk^3,4, Soufiene Bouallègue^1,5

CMC-Computers, Materials & Continua, Vol.69, No.2, pp. 2159-2180, 2021, DOI:10.32604/cmc.2021.018752

Abstract Paths planning of Unmanned Aerial Vehicles (UAVs) in a dynamic environment is considered a challenging task in autonomous flight control design. In this work, an efficient method based on a Multi-Objective Multi-Verse Optimization (MOMVO) algorithm is proposed and successfully applied to solve the path planning problem of quadrotors with moving obstacles. Such a path planning task is formulated as a multicriteria optimization problem under operational constraints. The proposed MOMVO-based planning approach aims to lead the drone to traverse the shortest path from the starting point and the target without collision with moving obstacles. The vehicle moves to the next position… More >

Rabii Fessi¹, Hegazy Rezk^2,3,*, Soufiene Bouallègue^1,4

CMC-Computers, Materials & Continua, Vol.68, No.2, pp. 2265-2282, 2021, DOI:10.32604/cmc.2021.017237

Abstract The research on Unmanned Aerial Vehicles (UAV) has intensified considerably thanks to the recent growth in the fields of advanced automatic control, artificial intelligence, and miniaturization. In this paper, a Grey Wolf Optimization (GWO) algorithm is proposed and successfully applied to tune all effective parameters of Fast Terminal Sliding Mode (FTSM) controllers for a quadrotor UAV. A full control scheme is first established to deal with the coupled and underactuated dynamics of the drone. Controllers for altitude, attitude, and position dynamics become separately designed and tuned. To work around the repetitive and time-consuming trial-error-based procedures, all FTSM controllers’ parameters for… More >

Yipu Wang¹, Yonghua Wang^1,2,*, Zheming Liu¹, Huadong Yu¹, Jinkai Xu¹

Journal of Renewable Materials, Vol.9, No.5, pp. 923-941, 2021, DOI:10.32604/jrm.2021.014138

Abstract Noise pollution is one of the contemporary environmental pollution, which seriously damages people’s green and healthy life. In order to further improve the low frequency sound absorption performance of microperforated panel (MPP), a new plastocene coupled microperforated plate (PCMPP) is proposed. The acoustic properties of PCMPP with different apertures and perforation ratio were measured by transfer function method and compared with that of conventional MPPs. It is found that when the aperture was 0.8 mm, the peak value of sound absorption coefficient of PCMPP decreased by 150 Hz compared with MPP. In a certain range, PCMPP with larger apertures showed… More >

Tina Chaudhary^1,*, Arshad Noor Siddiquee², Arindam Kumar Chanda³, Shafi Ahmad², Irfan Anjum Badruddin^4,*, Zahid A. Khan²

CMES-Computer Modeling in Engineering & Sciences, Vol.126, No.1, pp. 241-259, 2021, DOI:10.32604/cmes.2021.013368

Abstract The purpose of this research is to obtain the optimum cutting parameters to achieve the dimensional accuracy of Nimonic alloy miniature gear manufactured using Wire EDM. The cutting parameters investigated in this study are current, pulse on time (PON), pulse off time (POFF), wire tension (WT) and dielectric fluids. Ethylene glycol, nanopowder of alumina and oxygen are mixed to demineralized water to prepare novel dielectric fluids. Deviation in inner diameter, deviation in outer diameter, deviation in land and deviation in tooth width are considered to check the dimensional accuracy. Taguchi L₁₆ is employed for experimental design and multiple response optimization… More >

N. Ganesh¹, R. K. Ghadai², A. K. Bhoi³, K. Kalita^4,*, Xiao-Zhi Gao⁵

CMES-Computer Modeling in Engineering & Sciences, Vol.124, No.2, pp. 459-476, 2020, DOI:10.32604/cmes.2020.09645

Abstract Electrical Discharge Machining (EDM) is a popular non-traditional machining process that is widely used due to its ability to machine hard and brittle materials. It does not require a cutting tool and can machine complex geometries easily. However, it suffers from drawbacks like a poor rate of machining and excessive tool wear. In this research, an attempt is made to address these issues by using an intelligent predictive model coupled global optimization approach to predict suitable combinations of input parameters (current, pulse on-time and pulse off-time) that would effectively increase the material removal rate and minimize the tool wear. The… More >

J. Labaki¹, E. Mesquita², R. K. N. D. Rajapakse³

CMES-Computer Modeling in Engineering & Sciences, Vol.103, No.5, pp. 281-313, 2014, DOI:10.3970/cmes.2014.103.281

Abstract This paper introduces a numerical model to investigate the vibratory response of elastic and rigid circular plates embedded in viscoelastic, transversely isotropic, three-dimensional layered media. In the present numerical scheme, the boundary-value problem corresponding to the case of time-harmonic concentrated and distributed axisymmetric vertical ring loads within a layered half-space is formulated according to an exact stiffness method. Its solution results in the required influence functions for the modeling of the present problem. The case of an embedded flexible plate is formulated in terms of a variational method. The deflection profile of the plate is written in terms of generalized… More >