加速度計出力を用いた柔軟構造衛星のシステム同定

Abstract

This paper presents an application of single-input multi-output (SIMO) system identification in the time domain using accelerometer outputs that are typical of satellite on-board sensors.The algorithm is suitable for the on-orbit system identification of six degrees-of-freedom spacecraft motions using the responses to thruster impulse inputs. Our new method identifies the input and output matrices of a SIMO collocated system by applying a recursive least-squares iteration scheme to refine the matrices obtained from conventional ERA. In a numerical simulation of an actual spacecraft to verify the algorithm, a mathematical model of the Engineering Test Satellite-VI (ETS-VI) is excited by a body-mounted thruster, and the translational and rotational accelerometers are measured simultaneously. Our method successfully identifies all of the natural frequencies, damping ratios, and mode shape vectors except for pitch rotational motion that has low sensitivity, confirming its validity.