A Comprehensive RVD Simulation Environment for GNC Algorithms Design and Implementation

This paper proposes a strategy for the Chaser position tracking during the approaching maneuver to a passive vehicle (Target), oriented to the development of a comprehensive simulator and guidance algorithms for rendezvous (RVD) maneuvers, starting from far range rendezvous to the final approach. The simulator is designed to reproduce space flight operations along Low Earth Orbits (LEO) for Chaser-Target systems. The simulation environment includes accurate and realistic models of sensors and actuators (thrusters and reaction wheels), which allow a complete simulation of autonomous spacecraft behavior orbiting in LEO. A simplified model of the external disturbances is also considered. Different guidance algorithms are considered for the guidance, navigation and control (GNC) subsystem of the Chaser vehicle. An optimal proportional navigation (PN) algorithm for the far range rendezvous and, in the final phase, a cone approach based on a continuous thrust straight-line maneuver are implemented. In addition, a comparison with ZEM-ZEV (Zero Effort Miss-Zero Effort Velocity) algorithms have been accomplished. Extensive simulations, that include different phases of the approaching maneuver, mainly identified on the Chaser distance from the Target, are performed to validate the feasibility and the tracking performance of the proposed guidance algorithms.