TY - JOUR ID - 21522 TI - Model reference adaptive control of a small satellite in the presence of parameter uncertainties JO - Scientia Iranica JA - SCI LA - en SN - 1026-3098 AU - Ahmadi Dastgerdi, K. AU - Pazooki, F. AU - Roshanian, J. AD - Department of Mechanical and Aerospace Engineering, Science and Research Branch, Islamic Azad University, Tehran, Iran AD - Department of Aerospace Engineering, K.N. Toosi University of Technology, Tehran, Iran Y1 - 2020 PY - 2020 VL - 27 IS - 6 SP - 2933 EP - 2944 KW - Discrete-Time KW - Model Reference Adaptive Control (MRAC) KW - Parameter Uncertainty KW - Satellite DO - 10.24200/sci.2019.50455.1704 N2 - An accurate control algorithm for small satellites is critical to the mission's success. In this paper, a novel discrete-time Model Reference Adaptive Control algorithm (MRAC) is developed based on unified approach for attitude control of a three-axis stabilized nonlinear satellite model. The linearized model of satellite with unknown dynamic parameters is derived and Recursive Least Squares (RLS) algorithm is used to identify the linear model’s unknown parameters. In order to take into account the nonlinear model of satellite dynamics, the proposed MRAC strategy is used considering the linear model, the estimation error; and the difference between the actual nonlinear system and the linear model outputs. The actual nonlinear model of satellite includes moments of inertia uncertainties, external disturbances, and sensor noise on the outputs. The introduced controller performance is compared with a conventional discrete -time MRAC which demonstrates excellent simultaneous regulation and tracking capabilities. UR - https://scientiairanica.sharif.edu/article_21522.html L1 - https://scientiairanica.sharif.edu/article_21522_d0632d61fddf5a288217e478ab5d1528.pdf ER -