The Geometric State Manager: A real-time distributed geometric model manager

This dissertation is concerned with the theory and implementation of a geometric model manager for robots and their sensors in a distributed real-time computing environment. The model manager communicates with sensor processors and task planning processors while ensuring that the state of the environment model is consistent and up-to-date. This Geometric State Manager (GSM) supports geometric and kinematic reasoning with uncertain, inaccurate, and sometimes conflicting sensor measurements and provides support for sensor fusion. A new model for orientational uncertainty is introduced based on the theory of random unit quaternions. This model supports a more unified approach to the representation of positional and orientational uncertainty. The management of a common and consistent world model is inherently a centralized task. However, the state of the environment must also be efficiently distributed to GSM clients, each of which may have different needs. This places a decentralizing force on the design of the GSM. This thesis discusses the theory and implementation of a general-purpose distributed model manager to meet these requirements.