Decentralized Control of Electromagnetic ChipSat Swarm Formations

• Autor(a) principal: Gondar, Rui Manuel Gomes
• Data de Publicação: 2021
• Tipo de documento: Dissertação
• Idioma: eng
• Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
• Texto Completo: http://hdl.handle.net/10400.6/11700
• topic: Algoritmos de Control da Orientação e Navegação; Chipsats; Controlo Eletromagnético Descentralizado; Enxame de Satélites; Equações Hcw; Magnetorquers; Voo Em Formação; Domínio/Área Científica::Engenharia e Tecnologia::Engenharia Aeronáutica

Small satellite formation missions offer new options for space exploration and scientific experiments. Groups of satellites flying within short relative distances allow various important applications, such as spatially distributed instruments for atmospheric sampling or remote sensing systems. The ability to independently control the relative motion of each satellite is crucial to establish a swarm formation, using a large number of satellites moving along bounded relative trajectories. This type of mission poses several constraints on mass, size, and energy consumption; therefore, an autonomous and selfsufficient approach is necessary to assure relative motion control. A novel concept of miniaturized satellites, referred to as ChipSats, consists of a single printed circuit board which can be equipped with different sets of microelectronic components including power and communication systems, a variety of sensors, and a microcontroller. This study considers a swarm of ChipSats equipped with magnetorquers, operating at extremely short relative distances, and using the electromagnetic interaction force for relative motion and attitude control, assuming the absolute position and relative state of each unit is known. Despite the limitations imposed by using magnetorquers as the sole actuators onboard, the dipole interaction between drifting satellites can be used to achieve bounded relative trajectories, and to establish and maintain a compact swarm. Following a decentralized approach, the ChipSats are periodically linked in interchangeable pairs in order to apply the Lyapunov-based control algorithm and prevent relative drift between all satellites in the swarm. The magnetic dipole moments are used for angular velocity damping when orbit control is not required, and a repulsive collision avoidance electromagnetic control force is applied when two ChipSats are within dangerously close proximity to each other. The performance assessment is conducted through Monte Carlo simulations using MATLAB, by analyzing operational parameters and the effect of initial conditions after deployment.