| || Trajectory Correction Flight Control System using Pulsejet on an Artillery Rocket
Author : Gupta, S. K.;Saxena, S.;Singhal, Ankur;Ghosh, A. K.
Source : Defence Science Journal ; Vol:58(1) ; 2008 ; pp 15-33
Subject : 629.7 Aeronautics
Keywords : Pulsejet;Trajectory-tracking flight control system;Impact point dispersion;Trajectory-tracking window size;Inertial measurement unit;Trajectory correction flight control system
Abstract : A trajectory correction flight control system is small and durable, and consists of a lateral pulsejet ring mounted on the rocket body. The pulsejet ring consists of a finite number of individual pulsejets. Each pulsejet on the ring imparts a single, short-duration, large force to the rocket in the plane normal to the rocket axis of symmetry. Lateral pulsejets are used by flight control system to assist the rocket to follow a pre-specified (command) trajectory. The trajectory-tracking flight control system computes the position error by comparing the measured position of the rocket with the pre-specified trajectory. In actual application, the position of the rocket could be measured using in-house inertial measurement unit (IMU) or by ground-based-tracking radar system located at the firing site. A study has been undertaken to explore the feasibility of reducing the impact point dispersion of a routinely-used artillery rocket using lateral pulsejets coupled to a trajectory correction flight control system. Simulation studies have been conducted to arrive at tuning parameters, namely the tracking error window size, the required elapsed time between the pulsejet firings and the angle of tolerance between the tracking error and the individual pulsejet force. Further, the robustness of the methodology wrt measurement noise has also been evaluated.