Implementation of a real-time attitude system for the stabilization control of a quad-rotor robot

The real-time estimation of the attitude and heading is a fundamental task for an autonomous vehicle to operate properly. Nowadays, the determination of this information using low cost sensors is a very active research area in robotics applications. Therefore, a new method in sensory fusion to attitude estimation using low cost devices is addressed in this paper. The Attitude and Heading Reference System (AHRS) consists of three-axes solid-state or MEMS gyroscopes, accelerometers and magnetometers and also an on-board processing system. The algorithm uses direction cosine matrix theory to obtain the desired information from the low cost sensors. Using the computed attitude, a simple approach to the stabilization of a quad-rotor robot while in flight was implemented. Towards the stabilization of the quad-rotor, AHRS must be used as a feedback for the PD controllers. Experimental results showed that the AHRS and PD controllers implemented can be used to stabilize the quad-rotor during flight. The responses of the system can be visualized in graphics plotted in Matlab or through a virtual graphic interface developed.