Controlled Orbital Dynamics of Low Altitude Formations by means of Electric Propulsion

Guidance, navigation and control system has a great relevance in the design of a formation flying mission. Severe requirements, in terms of relative position's acquisition and maintenance, are common to these missions and a deep investigation is needed in order to identify optimal and feasible solutions. This paper describes a low-thrust electrical motor and proposes its use in order to provide the required orbital control: the effects of the limitations and inaccuracies of the actuator and of the sensor are taken into account in order to implement a realistic tool, able to simulate the actual behaviour. In this way it is possible to verify the actual effectiveness of control strategies developed to overcome these limitations. In particular, a digitalized regulator with fixed duty cycle is implemented as a derivation of the classical LQR theory, providing interesting performances for a large number of applications.