Aerospace Science and Technology
Designing a Hybrid GEO-LEO Constellation Pattern for Regional Satellite Navigation in Iran

Shahrokh Zohrabzadeh Bozorgi; Abolghasem Naghash

Volume 16, Issue 1 , June 2023, , Pages 77-87

  In this paper, a few hybrid satellite constellations including combinations of LEO and GEO satellites for providing satellite navigation and positioning services for users in Iran have been designed and proposed. The performance of the constellations has been analyzed based on DOP values variations. ...  Read More

Aerospace Science and Technology
Design of Multi-Input Multi-Output Controller for an Unmanned Aerial Vehicle by Eigenstructure Assignment Method

Ali Motamedi; Abolghasem Naghash

Volume 14, Issue 1 , June 2021, , Pages 117-127

  The purpose of this paper is to present a Multi-Input Multi-Output (MIMO) linear controller based on the eigenstructure assignment method for a fixed-wing Unmanned Aerial Vehicle (UAV) in longitudinal and lateral-directional channels. To this end, a six degree-of-freedom model of the aerial vehicle is ...  Read More

Designing a Fault-Tolerant Control System for the Boeing 747

Reza Soltani Nezhad; Abolqasem Naghash

Volume 13, Issue 1 , June 2020, , Pages 1-9

  This article examines the fault tolerance control (FTC) system for the Boeing 747. to reach this goal, firstly 6 degrees of freedom equations are simulated and linearized by using dynamic inversion method. Then, the system is controlled by a linear proportional-integral-derivative controller. To control ...  Read More

Midcourse Trajectory Shaping for Air and Ballistic Defence Guidance Using Bezier Curves

Alireza Mohamadifard; Abolqasem Naghash

Volume 8, Issue 2 , September 2011, , Pages 87-95

  A near-optimal midcourse trajectory shaping guidance algorithm is proposed for both air and ballistic target engagement mission attributes for generic long range interceptor missile. This guidance methodology is based on the maximum final velocity as the objective function and maximum permissible flight ...  Read More

Design of Nonlinear Robust Controller and Observer for Control of a Flexible Spacecraft

maryam malekzadeh; Abolqasem Naghash; H.Ali Talebi

Volume 7, Issue 2 , September 2010, , Pages 81-91

  Two robust nonlinear controllers along with a nonlinear observer have been developed in this study to control a 1D nonlinear flexible spacecraft. The first controller is based on dynamic inversion, while the second one is composed of dynamic inversion and µ-synthesis controllers. The extension of dynamic ...  Read More

Incremental Predictive Command of Velocity to Be Gained Guidance Method

Nematollah Ghahramani; Abolqasem Naghash; Farzad Towhidkhah

Volume 5, Issue 3 , July 2008, , Pages 99-105

  In this paper, a new incremental predictive guidance method based on implicit form of velocity to be gained algorithm is proposed. In this approach, the generalized incremental predictive control (GIPC) approach is applied to the linearized model for compensating the guidance error. Instead of using ...  Read More

Trajectory Optimization for a Multistage Launch Vehicle Using Nonlinear Programming

Abolqasem Naghash

Volume 2, Issue 3 , September 2005, , Pages 9-18

  This work is an example of application of nonlinear programming to a problem of three-dimensional trajectory optimization for multistage launch vehicles for geostationary orbit missions. The main objective is to minimize fuel consumption or equivalently to maximize the payload. The launch vehicle considered ...  Read More