With the miniaturization of processing units, sensors, and communication devices rapidly progressing, interest in small autonomous unmanned aerial vehicles (UAVs) is currently expanding exponentially. This book provides a survey of the requirements and suitable solution approaches that are typically connected with the system architecture of small autonomous UAVs. Remarkably, there is not as much variation in the set of these requirements as one might at first glance expect. Any autonomous UAV needs to provide means of communication with its users, to be able to measure its position and attitude, to move to certain positions, and often to perform certain measurements and/or manipulation there. This book presents solutions that have been successfully applied in actually working small autonomous UAV systems. Special focus is placed at flight controller design, introducing a novel iterative view of nonlinear control systems, which is easy to grasp, formally verified, and not limited to UAV applications. The book is aimed at students and professionals specifically interested in small UAV design, or interested in the design of miniaturized complex embedded real-time systems in general.