Friction Estimation of Electromechanical Actuator based Flex Nozzle Control System using Firefly Algorithm

Thrust vector controlling in space systems are carried out by Flex Nozzle Control systems. The system comprises of submerged nozzle which is connected to the main motor through a flexible joint and can be aimed in all directions with the help of actuation systems. Flex Nozzle Control (FNC) integrated with Electromechanical Actuators (EMAs) are used to aim the rocket nozzle for unerring steering of a launch vehicle.But EMAs shows certain non linear behaviour due to the frictional effects like stiction and coulomb friction, bringing down the overall system performance. To enhance the performance system should be compensated for its non linearity. It is important to first estimate the value of unknown friction present in the system. Instead of the complicated analytical methods we can use the natural algorithms which incorporate large spaces to obtain accurate results at more ease. In this work, Fire fly Algorithm is proposed to estimate the friction so as to provide suitable compensation. The proposed scheme is implemented in MATLAB/SIMULINK.