Development of a ground test facility for hardware-in-the-loop validation of multiple spacecraft operations

다국어 초록 (Multilingual Abstract)

This dissertation presents a ground-based hardware-in-the-loop test facility, which is developed to verify and demonstrate autonomous guidance, navigation, and control algorithms for spacecraft proximity operations and formation flying maneuvers. The test facility consists of two complete spaceflight simulators, an aluminum-based operational arena, and a set of infrared motion tracking cameras. Comprising these elements together, the testbed is capable of representing space activities under circumstances prevailing on the ground. The spaceflight simulators have a maximum of five-degree-of-freedom in a quasi-momentum-free environment, which is produced by a set of linear/hemispherical air-bearings and a horizontally leveled operational arena. The tracking system measures and provides real-time three-dimensional position and attitude to the agents. The testbed design is illustrated in detail for every element throughout in this work. The practical hardware characteristics of the active/passive measurement units and internal actuators are numerically identified in detail from various perspectives. An adaptive controller is developed to compensate uncertain parameters which the testbed carries itself and experiences while in operation. The proposed controller is intended to produce non-negative thrust magnitude so that there is no logical process while determining the active thruster with respect to the overall control effort. Throughout both numerical and experimental results, the effectiveness of the proposed controller and the operational capabilities of the developed testbed is clearly shown. In addition to the testbed platform construction, a vision-based navigation system is developed and implemented to show future expandabilities of the new test facility. These results support the successful development of the entire facility and enable us to implement and verify various spacecraft proximity operation strategy in the near future.