Abstract: A method which providing three-axis attitude control by the gimbaled thruster gimbal and yaw attitude control thruster was proposed. Firstly, the multi-body dynamics equations with the upper stage body, gimbaled thruster and gimbal support were built based on the Kane equation. The gimbaled thruster′s disturbance torque and gimbal angle formulas when the gimbaled thruster working were derived. Sceondly, the upper stage attitude control law was designed based on the variable structure control law, that not only achieved 10^-3 atttiude control precision, but allowed the gimbaled thruster′s thrust direction achieve the direction determined by the guidance system as well as was via the mass center of upper stage. Finally, the validity of the proposed method was verified by numerical simulations.

Key words: Variable structure control, Gimbaled thruster, Orbital transfer, Attitude control