抄録
Reusable Launch Vehicles (RLVs) are expected to become important transportation systems in future space exploration. RLVs are vehicles which have the ability to be launched into space, carry a payload to orbit and finally landing back on earth without using any expendable rockets. Due to this reason, RLVs are capable to reduce rocket launch operation expenses for space exploration. However, RLVs travel from earth's surface to space in uncertain environments causing the values of the parameters for the RLVs dynamic equations to be inconsistent. Therefore, various researchers have proposed several adaptive control methods to counter this problem. Quaternion is often being used in attitude control system of space vehicles such as rockets and satellites because quaternion has no singular point when the pitch angle approaches ±90[deg], which is a problem for Euler Angles. In this paper, we propose a digital adaptive feedback linearization control method using Quaternion for controlling the attitude of a winged rocket, a type of RLV. The proposed control method is implemented into the control system of a propulsion engine model. The effectiveness of the control system is demonstrated through computer simulations under the condition that the rocket's pitch angle during lift-off is in singularity of Euler angles. Simulation results show that the winged rocket is able to be launched from a vertically upward launch phase, flying into ascending phase and subsequently making a transition into a gliding phase successfully. The simulation results demonstrated the effectiveness of the proposed method in controlling a winged rocket.
