DEVELOPMENT OF ATTITUDE DETERMINATION AND CONTROL SYSTEM OF TOKYO TECH NANO-SATELLITE, CUTE-1.7 + APD II

摘要

Recently, techniques of attitude determination and control are required for nano-satellites to achieve advanced missions, remote sensing, astronomic observation, and so on. LSS (Lab.for Space Systems) at Tokyo Institute of Technology developed an attitude determination and control system (ADCS) for Cute-1.7 + APD of 10~*10~*20cm3 in volume which is the second nano-satellite of LSS. This ADCS is composed of magnetic sensors, sun sensors, gyro sensors and three magnetic torquers which require less power and have no mechanical moving parts. Cute-1.7 + APD was successfully launched on February 22nd of 2006 and was operated for about one month. But we could not conduct enough experiments for the ADCS because of troubles due to radiation. Now, LSS is developing the third nano-satellite Cute-1.7 + APD II of 10~*15~*20 cm3 in volume and of 3kg in mass to improve Cute-1.7 + APD's subsystem design and to fulfill all of the planned missions, and it will be launched in fall of 2007 by using an Indian rocket PSLV. Concerning its attitude determination system, we adopt both extended Kalman filter (EKF) and unscented filter (UF), and we will compare on-orbit performance of EKF with that of UF. Concerning its attitude control system, the output power of magnetic torquers is strengthened and several control methods using the magnetic torquers will be examined on-orbit. In this paper, we explain ADCS for the Cute-1.7 + APD II, and we describe results of various ADCS simulations and experiments on the ground.