Abstract
Passive spacecraft attitude control using spin-stabilization is considered as one of traditional and low-cost control strategies. In literature, low-cost state-of-the-art slew algorithms based on single thruster are designed to perform large angle spin axis attitude manoeuvre. The existing research and analysis shows that half-cone category algorithms are open-loop slew control and they are sensitive to spin rate perturbation. In order to improve the tolerance of spin-rate perturbations, the work is motivated to introduce closed-loop attitude feedback using sensors. For nano-satellites, especially for cubesat missions, thrusters are restricted to its size and propellant consumption, so thrusters are not usually chosen as the actuators on nano-satellites. Alternatively, other actuators such as magnetorquers and momentum wheels are feasible in nano-satellite missions. For nano-satellite missions, a novel low-cost slew control algorithm using single-magnetorquer is investigated based on the philosophy of single-thruster slew algorithms. This thesis gives an overview of the research on single actuator control of a prolate spin-stabilised around its minimum moment of inertia axis. Two novel feedback slew algorithms using single-thruster have been developed. Thorough robustness analyses have been performed to estimate how well these novel algorithms perform in the presence of spin-rate disturbances compared with co-responding open-loop algorithms. The results of these analyses indicate that with the help of attitude feedback, these feedback slew algorithms show more robust performance compared with their corresponding open-loop algorithms. A feedback slew algorithm using single-magnetorquer has also been developed based on Half-Cone slew philosophy using single-thruster, dealing with large angle attitude manoeuvre problem where magnetorquer is applied for the mission. Simulations based on STRaND-1, a 3-U cubesat launched by Surrey Space Centre and Surrey Satellite Technology Ltd., was chosen as a use case to simulate attitude manoeuvres parallel with Earth equatorial plane. These manoeuvres were carried out at different orbital positions. To conclude, the research presented in this thesis has led to two novel slew algorithms using single-thruster and thorough analysis proves that these algorithms greatly improve the robustness on spin-rate perturbations. A feedback algorithm using single-magnetorquer has also been developed dealing with large angle attitude manoeuvre problem. Future directions for research in this area is also recommended.