Multi-Spacecraft Sliding Mode Control with hybrid dynamics using Dual-Gimbal Variable-Speed CMGs with integrated Fault Detection and Isolation systems

This thesis presents the Multi sliding mode control of spacecrafts with hybrid dynamics, distinguishing between the part of the satellite that can be considered rigid from the parts that should be considered flexible, like the antennas. The consensus protocol between the spacecrafts has been modeled through the construction of the Laplacian matrix that describes the communication topology. The controlled system has been actuated through parallel mounted Dual-Gimbal Variable-Speed CMGs for each spacecraft, modeled from scratch. Each axis of rotation of each implemented actuator is controlled by a PID controller. The steering law defines the gimbal commands that will be the reference for the latter controller. Moreover, each spacecraft has an integrated Fault Detection and Isolation (FDI) subsystem. For this implementation, the spacecraft is Single Failure Tolerant: the system have an alternative solution in case of a single failure. Once a failure is detected and isolated, a reserve actuator is activated to compensate. If the reserve actuator does not work properly, the satellite is rejected from communication and the Multi-Spacecraft system rearrange its own communication topology.