| Summary: | Prior to launch, space craft instruments need to be tested in a relevant environment to
prove operational functionality. Thus, we have developed an ion source to stimulate thermal
plasma instruments in a vacuum chamber. This dissertation presents the mechanical design
of the source, simulations of the potentials and charged particle trajectories in and around
the source, and vacuum chamber measurements of the emitted ion beam. Once the ion
source is understood, it is successfully used to test a typical ion instrument. Further aspects
of the ion source, efficiency, thermionic filament emission, and collision frequencies are also
discussed. === Doctor of Philosophy === This dissertation explores ways to improve autonomous navigation in unstructured terrain conditions, with specific applications to unmanned casualty extraction in disaster scenarios. Search and rescue applications often put the lives of first responders at risk. Using robotic systems for human rescue in disaster scenarios can keep first responders out of danger. To enable safe robotic casualty extraction, this dissertation proposes a novel rescue robot design concept named SAVER. The proposed design concept consists of several subsystems including a declining stretcher bed, head and neck support system, and robotic arms that conceptually enable safe casualty manipulation and extraction based on high-level commands issued by a remote operator. In order to enable autonomous navigation of the proposed conceptual system in challenging outdoor terrain conditions, this dissertation proposes improvements in planning, trajectory tracking control and terrain estimation. The proposed techniques are able to take into account the dynamic effects of robot-terrain interaction including slip experienced by the vehicle, slope of the terrain and actuator limitations. The proposed techniques have been validated through simulations and experiments in indoor and simple outdoor terrain conditions. The applicability of the above techniques in improving tele-operation of rescue robotic systems in unstructured terrain is also discussed at the end of this dissertation.
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