Method for improving maneuverability and controllability by simultaneously applying both reaction wheel-based attitude controller and thruster-based attitude controller

An attitude control system of a spacecraft of an artificial satellite, the system comprising:

• a thruster-based attitude controller which control firing time of a thruster mounted on the spacecraft;
• a thruster model calculating a first torque in proportion to a thruster firing time input from the thruster-based attitude controller;
• a reaction wheel-based attitude controller controlling driving of a reaction wheel mounted on the spacecraft;
• a reaction wheel speed controller calculating a reaction wheel torque using a value input from the reaction wheel-based attitude controller;
• a reaction wheel model calculating an angular momentum and a second torque using the reaction wheel torque;
• a sum summing up the first torque and the second torque;
• and
• a spacecraft dynamics model simulating rotational motion of the spacecraft according to the torque input from the sum.

An attitude control method of a spacecraft of an artificial satellite, the method comprising:

• calculating a thruster firing time for an attitude control of the spacecraft;
• calculating a first torque in proportion to the calculated thruster firing time, the first torque occurring in the spacecraft due to a thruster;
• calculating an angular momentum and a torque acting on a reaction wheel;
• calculating a second torque using the calculated torque of the reaction wheel, the second torque occurring in the spacecraft due to the reaction wheel;
• and
• summing up the first torque and the second torque to calculate an angular velocity of the spacecraft for the attitude control of the spacecraft.