Control, navigation and collision avoidance for an unmanned aerial vehicle

This article reports the development of an unmanned aerial vehicle capable of attitude estimation and stabilization through the implementation of a nonlinear complementary filter and proportional-integral rate controllers. Four infra-red sensors and an ultrasonic sensor are integrated with the main platform for the collision avoidance schemes and for altitude control, respectively. Critical mission capabilities for the vehicle such as altitude hold and collision avoidance are developed. An outdoor navigation scheme and collision avoidance algorithms are also proposed to enhance the vehicle autonomy. Experimental results have shown that the implemented attitude and altitude controllers are effective and the platform is capable of navigating autonomously with user-defined waypoints. The collision avoidance algorithms allow the platform to avoid obstacles, both reactively and in the midst of navigation routines.