Optimal nutation suppressing method for detumbling satellites via a flexible deceleration device

Malfunctioning satellites are normally in tumbling state due to residual angular momentum, rendering direct capture impossible. Therefore, detumbling these objects is an indispensable phase for on-orbit safe capture. A novel detumbling method, using a flexible device (e.g., brush or rod) to approach and compliantly contact the target objects, has been proposed to successfully avoid the major drawback of potential risky collisions. Although efficient, the flexible-device-based method suffers from two limitations: (i) Due to complex three-axis rotary motion, it is extremely difficult to predetermine the contact position on the target satellite so as to ensure simultaneous suppression of rotation and nutation. (ii) The conventional finite-element-based dynamic model of the large-deformation device is high-dimensional, causing unacceptable computing time for the on-orbit task. To address these problems, this paper proposes an optimal nutation suppressing method to ensure the most efficient suppression of nutation during detumbling. In addition, a highly efficient data-driven model is proposed to accurately describe the large-deformation flexible device for real-time on-orbit computation. Finally, numerical simulations are carried out to verify the feasibility and efficiency of the present method.