121 厳密線形化された宇宙機の相対位置・姿勢運動に対するエネルギー最小制御

Abstract

The present paper proposes a control scheme for position and attitude tracking of a spacecraft in order to inspect a malfunctioning satellite by maneuvering around the satellite. The proposed method is a nonlinear controller based on the exact-linearization techniques. The exact-linearization method is powerful for controlling nonlinear systems such as the position and attitude control problem treated in the present paper, because each state variable of the linearized system can be controlled independently. After nonlinear systems are exactly linearized, any kind of control method can be applied to control the systems. The Linear Quadratic Regulator (LQR) is one example of such methods that can be used for controlling the exact-linearized systems. However, from the real energy point of view, the exact-linearization method combined with LQR is not optimal, because the performance index is not an energy function and is optimized with respect to the exact-linearized state variables, which are not equal to the real state variables. In the present study, considering the rotational motion of a target satellite, position of the chaser satellite relative to the target and the period of rotational motion of the target satellite, the energy consumption for the fly-around motion using the exact-linearization is optimize. The effectiveness of the proposed method is verified, in comparison with the exact-linearized method with LQR and the adaptive exact-linearized method with LQR, through numerical simulation.