Full control of a quadrotor

The research on autonomous miniature flying robots has intensified considerably thanks to the recent growth of civil and military interest in unmanned aerial vehicles (UAV). This paper summarizes the final results of the modeling and control parts of OS4 project, which focused on design and control of a quadrotor. It introduces a simulation model which takes into account the variation of the aerodynamical coefficients due to vehicle motion. The control parameters found with this model are successfully used on the helicopter without re-tuning. The last part of this paper describes the control approach (integral backstepping) and the scheme we propose for full control of quadrotors (attitude, altitude and position). Finally, the results of autonomous take-off, hover, landing and collision avoidance are presented.

I. INTRODUCTION

Flying objects have always exerted a great fascination on man encouraging all kinds of research and development. This project started in 2003, a time at which the robotics community was showing a growing interest in Unmanned Aerial Vehicles (UAV) development. The scientific challenge in UAV design and control in cluttered environments and the lack of existing solutions was very motivating. On the other hand, the broad field of applications in both military and civilian markets was encouraging the funding of UAV related projects. It was decided from the beginning of this project to work on a particular configuration: the quadrotor. The interest comes not only from its dynamics, which represent an attractive control problem, but also from the design issue. Integrating the sensors, actuators and intelligence into a lightweight vertically flying system with a decent operation time is not trivial.