Concurrent attitude-position control of under-actuated nanosatellites for formation flying

This paper presents formation flying for under-actuated nanosatellites based on concurrent attitude-position control. Compared to existing methods that rely on independent rotational and translational control, here because of under-actuated inherent attribute of the problem a triple-tiered approach based on concurrent attitude-position control is developed. The proposed approach consists of following sub-control layers: at first a virtual fully-actuated model of nanosatellites based on relative motion is introduced. Consequently, an adaptive finite-time attitude control is proposed to align nanosatellites towards obtained virtual translational inputs. Finally, using the virtual translational inputs and attitude of nanosatelites, the desired thrusts are computed. The proposed idea shed light on future nanosatellites formation flying missions. Simulation results are presented to illustrate the applicability of the proposed method in nanosatellites.