RIC (robust internal-loop compensator) based flight control of a quad-rotor type UAV

A QRT (quad-rotor type) hovering robot system is developed for quick detection and observation of the circumstances under calamity environment such as indoor fire spots. The UAV (unmanned aerial vehicle) is equipped with four propellers driven by each electric motor, an embedded controller, an INS (inertial navigation system) using three rate gyros and accelerometers, a CCD (charge coupled device) camera with wireless communication transmitter for observation, and an ultrasonic range sensor for height control. The developed hovering robot shows stable flying performances under the adoption of RIC (robust internal-loop compensator) based disturbance compensation and the vision based localization method. Although a model is incorrect, RIC method can design a controller by regarding the inaccurate part of the model and sensor noises as disturbances. The UAV can also avoid obstacles using eight IRs (infrareds) and four ultrasonic range sensors. This kind of micro UAV can be widely used in various calamity observation fields without danger of human beings under harmful environment.