Efficient Stabilization of Hybrid Coulomb Spacecraft Formations using Control Lyapunov Functions

Abstract

A control allocation algorithm using control Lyapunov functions to determine stabilizing charges and thrusts of hybrid Coulomb spacecraft formations (HCSFs) is presented. The goal is to stabilize a desired configuration while minimizing the thruster actuation and maximizing Coulomb actuation to minimize propellant usage. A proportion of the decrease of the control Lyapunov function is designated for Coulomb actuation and the rest is performed by thrusters. Simulations show that an 85% reduction of propellant compared to using solely thrusters is attainable using the proposed algorithm. It is shown that the best role for thrusters in a HCSF is to provide small corrections that cannot be provided by Coulomb actuation.