Satellite Formation Flying Control by Using Only Angle Measurements

This article investigates a practical formation control problem of multisatellite system, in which a group of small satellites are required to reach and maintain a desired geometric configuration under communication and measurement constraints. Toward this goal, we consider each satellite uses its local coordinate system and senses its neighboring satellites to obtain angle measurements. A formation control scheme using only the angle measurements is proposed to form the desired configuration. Moreover, the triangular and polygonal configuration cases are considered, in which the sum of interior angles of polygons being a constant is utilized to guarantee the stability of the determined final configuration. In particular, motivated by formation rigidity principles which mean that satellites' formation is seen as a multipoint framework that needs to be rigid to guarantee the uniqueness of the shape, we propose a formation determination approach to construct a rigid square configuration and prove that, compared with existing schemes, the inter-satellite relative positions and the knowledge of the communication topology are not needed for the proposed formation control law. Moreover, since the angle measurements are scalars and sensed with respect to the local coordinate system, the proposed angle-based formation control law is more robust against the misalignment on satelltes' coordinate systems. Simulation results are presented to illustrate the performance of the proposed control laws.