Space systems design (spacecraft, satellites, space stations and their equipment)
Mona Habibi; Mahdi Fakoor; Hadi Parviz Nowruzani
Volume 14, Issue 1 , March 2021, , Pages 65-75
Abstract
In this research, to investigate the effects of uncertainties on the natural frequency of satellite system attributed to the variation of layout components, the optimal layout of the satellite is performed utilizing particle swarm optimization (PSO) algorithm, considering stability and geometrical constraints. ...
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In this research, to investigate the effects of uncertainties on the natural frequency of satellite system attributed to the variation of layout components, the optimal layout of the satellite is performed utilizing particle swarm optimization (PSO) algorithm, considering stability and geometrical constraints. In order to produce random samples, enough number of results will be extracted, which are mass center of components, and based on the outputs, the finite element modeling of different samples by considering mass point is carried out. After modal analysis, mass and stiffness matrices are extracted, the simulation of Monte - Carlo runs based on Wishart random matrix theory and the eigenvalues of the matrix, i.e. natural frequencies, are obtained. Probabilistic distribution of natural frequencies is shown that in the proposed layout, the distribution of samples is very low and the variation of natural frequency is robust to the proposed optimal location.
M. M. Shokrieh; M. Fakoor; Z. Daneshjoo
Volume 6, Issue 4 , January 2014, , Pages 13-22
Abstract
Solar panels are used in satellites to absorb solar energy and supply the power needed for space missions. Mission definition and satellite lifetime is restricted by the way and the amount of energy that can be supplied for satellite subsystems. Therefore, the design of satellite solar panels as a unique ...
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Solar panels are used in satellites to absorb solar energy and supply the power needed for space missions. Mission definition and satellite lifetime is restricted by the way and the amount of energy that can be supplied for satellite subsystems. Therefore, the design of satellite solar panels as a unique source for power supply in satellites is very sensitive and important. In this paper, an efficient design for solar panels of a GEO communication satellite is proposed considering the maximum strength to weight ratio and minimum deflection. For this purpose different space structures including Iso Grid structures, honeycomb and composite plates are studied. Several structural analyses are performed on the models in order to assurance from the strength and durability of the model in space working environments. The design according to composite-honeycomb is introduced as the best model for solar panel structure. The proper configuration of layers is also presented by developing a code based on an optimization algorithm.
M. Fakoor; A. R. Kosari; H. Salehghaffari
Volume 6, Issue 2 , July 2013, , Pages 67-74
Abstract
This paper deals with the estimation of gyro model parameters and GEO satellite moment of inertia at the same time in transfer orbit phase. In order to fuse information of attitude determination subsystem sensors, an extended Kalman Filter has been employed. The estimation variables are including: quaternion, ...
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This paper deals with the estimation of gyro model parameters and GEO satellite moment of inertia at the same time in transfer orbit phase. In order to fuse information of attitude determination subsystem sensors, an extended Kalman Filter has been employed. The estimation variables are including: quaternion, angular velocity, moments of inertia, and gyro sensor model parameters which are bias and scale factor vectors. The satellite motion equations along with gyro sensor and quaternion measurements have been used to design an Extended Kalman Filter in order to estimate the desired states. The disturbance torque effect on moment of inertia identification has been also considered. Estimation results via some case studies demonstrate the numerical simulation section exhibit robustness and efficiency of Kalman Fillter.
