A novel decentralized consensus-based tracking control coupled to an optimal trajectory generator: application to a swarm of spacecraft exploring the rings of Saturn
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Le Compte, Shane. A novel decentralized consensus-based tracking control coupled to an optimal trajectory generator: application to a swarm of spacecraft exploring the rings of Saturn. Retrieved from https://doi.org/doi:10.7282/t3-ewdm-6b23
TitleA novel decentralized consensus-based tracking control coupled to an optimal trajectory generator: application to a swarm of spacecraft exploring the rings of Saturn
DescriptionA better comprehension of the formation of Saturn’s rings is crucial to understand oursolar system. Many questions remain unanswered despite the successes of the Cassini and Voyager missions to Saturn. Traditional large spacecraft prove to be problematic within planetary rings because collisions and consequent mission failure increase dramatically in the rings’ dynamically dense environment. Using a swarm of small unmanned probes with decentralized control and communication structures that are equipped with research instruments distributed amongst the swarm is a possible solution.
This thesis presents a novel, decentralized consensus-based tracking control algorithm for guiding such a swarm. This control algorithm is characterized by a trajectory generator based on the worst-case assumptions about both communication structures and ring particle environment. Specifically, in this thesis, a swarm of miniature spacecraft is modeled using a bifurcating artificial velocity potential field, traditionally applied to unmanned aerial vehicle modeling. The feasibility of such a swarm mission to Saturn’s rings is validated through repeated simulations involving uncertain environment conditions. Optimal model parameters, numerically calculated through the Monte Carlo method with the goal of minimizing fuel consumption and avoiding collisions, are used to generate an optimal reference trajectory for the swarm of spacecraft. A feedback tracking control with the optimal reference trajectory is designed under the assumption of unreliable and non-instantaneous communication among individual swarm agents. These scenarios are modeled using four different communication topologies as a function of craft separation distance. To mitigate this unreliability in communication, the decentralized consensus-based feedback tracking control is designed with the goal of having all the swarm agents’ current knowledge of the optimal trajectory converge to the given optimal reference trajectory.
The efficiency of the proposed algorithm is tested through numerical simulations in the MATLAB/Simulink environment. Finally, with the novel proposed consensus algorithm, the swarm can track its optimal reference trajectory, minimizing fuel consumption and reducing the probability of collisions, even when in unreliable communication conditions. Altogether, this makes the swarm spacecraft mission possible for successful exploration of Saturn’s rings.