**2. The RUAV platform**

During years of research, we have developed two RUAV platforms. The ServoHeli-20 RUAV platform was designed to be a common experimental platform for control and faulttolerant related study before 2009 (Qi, et al., 2006). The hardware components were selected with considerations of weight, availability and performance. After that, we miniaturized the hardware and used 40Kg industry helicopter. And we developed ServoHeli-40 RUAV platform. This RUAV platform can be used for control and navigation algorithm verification and experimental payload platform.
