This paper introduces a method for spacecraft rotation and translation control by on-off thrusters with guaranteed Lyapunov-stable tracking of linear dynamic models. In particular, the proposed control method switches on, at each time step, only those thrusters needed to maintain stability. Furthermore, the strategy allocates the configuration so that the minimum number of actuators is used. One of the benefits of the proposed method is that it substitutes both the thruster mapping and the pulse modulation algorithms typically used for real-time allocation of the firing thrusters and for determining the duration of the firing. The proposed approach reduces the computational burden of the onboard computer versus the use of classical thruster mapping algorithms, which typically involve iterative matrix operations. The paper presents analytical demonstrations, numerical simulations on a six-degree-offreedom spacecraft, and experimental tests on a hardware-in-the-loop three-degree-of-freedom spacecraft simulator floating over air pads on a flat floor. The method proves to be effective and easy to implement in real time.Received 21 September 2009; revision received 10 March 2010; accepted for publication 12 March 2010. This material is declared a work of the U.S. Government and is not subject to copyright protection in the United States. Copies of this paper may be made for personal or internal use, on condition that the copier pay the $10.00 per-copy fee to the Copyright Clearance Center, Inc., 222 Rosewood Drive, Danvers, MA 01923; include the code 0731-5090/10 and $10.00 in correspondence with the CCC.

This paper deals with the problem of spacecraft time-optimal reorientation maneuvers under boundaries and path\ud constraints. The minimum time solution with keep-out constraints is proposed using the particle swarm optimization\ud technique. A novel method based on the evolution of the kinematics and the successive obtainment of the control law is\ud presented and named as inverse dynamics particle swarm optimization. It is established that the computation of the\ud minimum time maneuver with the proposed technique leads to near-optimal solutions, which fully satisfy all the\ud boundaries and path constraints

No abstract

No abstract