Developing a ROS Enabled Full Autonomous Quadrotor

Abstract: The aim of this Master Thesis focuses on: a) the design and development of a quadrotor and b) on the design and development of a full ROS enabled software environment for controlling the quadrotor. ROS (Robotic Operating System) is a novel operating system, which has been fully oriented to the specific needs of the robotic platforms. The work that has been done covers various software developing aspects, such as: operating system management in different robotic platforms, the study of the various forms of programming in the ROS environment, evaluating building alternatives, the development of the interface with ROS or the practical tests with the developed aerial platform.
In more detail, initially in this thesis, a study of the ROS possibilities applied to flying robots, the development alternatives and the feasibility of integration has been done. These applications have included the aerial SLAM implementations (Simultaneous Location and Mapping) and aerial position control.
After the evaluation of the alternatives and considering the related functionality, autonomy and price, it has been considered to base the development platform on the ArduCopter platform. Although there are some examples of unmanned aerial vehicles in ROS, there is no support for this system, thus proper design and development work was necessary to make the two platforms compatible as it will be presented.
The quadrotor’s hardware has been mounted on an LTU manufactured platform, made through 3D printing, and its functionality has been evaluated in real environments. Although an aluminium platform has been also evaluated and tested with less satisfactory results.
For proper operation of the whole system, a connection between the quadrotor and the ground station has been established. In this case, an alternative connection between computers (for the case of an on board computer is mounted on the aircraft) or connection between computer and ArduCopter (for the case of no on board computers) have been designed.
A series of algorithms to perform the quadrotor control autonomously has been also implemented: Navigation with way points, rotation control and altitude control. The novelty of the proposed activities is that for the first time all these control modules have been designed and developed under the ROS system and have been operated in a networked manned from the ground station.
Finally, as it will be presented, a reader module for the adopted inertial measurement unit, currently under development by the University of Luleå (KFly), has also been developed. This device, although tested in controlled laboratory environments, has not yet became part of the quadrotor, but in the near future is expected to serve as a replacement to the on board computer.