“…Due to the recent advances in sensing, communication, computing, and control technologies, unmanned aerial vehicles (UAVs) have become vitally important in many engineering applications and our life, e.g., in surveillance, search and rescue (Pedro et al, 2013;Freddi et al, 2012;Chamseddine et al, 2012). As an example of UAV systems, the quadrotor helicopter is a relatively simple, affordable and easy to fly system and thus it has been widely used to develop, implement and test-fly methods in control, fault diagnosis, fault tolerant control (FTC) as well as multi-agent based technologies in formation flight, cooperative control, distributed control, mobile wireless…”