Control And Implementation Of A Quadrotor

Due to its character of simple structure, easy handling, maneuverability and flexibility, vertical takeoff and landing (VTOL), quadrotors have been used more and more widely with significant value in army and civil. Meanwhile the dynamics of quadrotor has the features of nonlinearity, underactuated, multivariable, great coupled and uncertainty, however, these features have made quadrotors become the typical controlled object in the field of controlling and widely used to verify the inovative theory and algorithm of control.Firstly, this paper have had a wide and careful survey of the current state of study and development of quadrotor, including control algorithm, modeling and identification methods, sensor technology, visual navigation and localization, the impressive and integerated experiment platform of quadrotor and some open source flight control projects.Secondly, according to the feature of mechanism and structure of the quadrotor, the paper has an analysis of the dynamics of the quadrotor based on Euler Angles, which including translation and rotation in space and providing the concerning basis to design the controller of quadrotor.This paper has provided two kinds of approaches to control the quadrotor. The first one is designed based on Proportion-Integration-Differentiation Control after the linearization of the dynamics of quadrotor. The second one is directly designed using the Backstepping approach based on the nonlinear dynamics of quadrotor. Then the simulation and analysis of these two approaches has been done with the OS4 Simulator.Besides, this paper has had a study and analysis of attitude algorithm of complementary filter based on Attitude and Head Reference System (AHRS), translation estimation based on optical flow and altitude estimation based on ultrasonic wave. In the end, a platform has been setup based on the open source flight control project Multiwii to accomplish the experiment of control of attitude/altitude/position of a quadrotor.