Fuzzy control of a nonlinear launch vehicle simulation to reach to the LEO orbit of earth
by
mahdy rezaei darestani
Khaje Nasir Toosi University of Technology-Tehran-Iran
Coauthors: mehran zare,Dr.jafar roshanian,hamed hossein afshari

Field of control in aerospace engineering especially in control of launch vehicles is one of the most important bases to study for developing a reliable and easy to set up control which could conduct our launch vehicle (LV) to the predetermined orbit. This action is a very heavy duty which we must overcome on it. To reach to this end in this study we used the fuzzy control. One of the most important reasons for this selection is easy set up and good performance due to sever changes of plant in order to the environmental and internal variable changes. In this way first we developed a six-degree-of-freedom simulation which comes from solving the three force equations and three moment equations that for this action we calculated all the exerted body and inertial forces and moments such as aerodynamic, propulsion, gravity. Here because of launching from earth we applied the spherical rotating model of earth which leads us approximately to a real launching. For the simulation first we must choose a launch vehicle from all the available launch vehicles to specify the body characteristic such as mass, moment of inertia, dimensions, etc. Here we assume an LV that with the payload of approximately 2 tons could safely launch to the 300 km orbit of earth. In this way, use of fuzzy controller helped to have a stable flight with minimum deflection of controlling thrust nozzles in the entire three coupled channels of our LV.

Date received: April 15, 2008

Copyright © 2008 by the author(s). The author(s) of this document and the organizers of the conference have granted their consent to include this abstract in Atlas Conferences Inc. Document # caxc-40.