  Research in mobile robotics often demands platforms that have an adequate
balance between cost and reliability. In the case of terrestrial robots, one of
the available options is the GNBot, an open-hardware project intended for the
evaluation of swarm search strategies. The lack of basic odometry sensors such
as wheel encoders had so far difficulted the implementation of an accurate
high-level controller in this platform. Thus, the aim of this thesis is to
improve motion control in the GNBot by incorporating a gyroscope whilst
maintaining the requisite of no wheel encoders. Among the problems that have
been tackled are: accurate in-place rotations, minimal drift during linear
motions, and arc-performing functionality. Additionally, the resulting
controller is calibrated autonomously by using both the gyroscope module and
the infrared rangefinder on board each robot, greatly simplifying the
calibration of large swarms. The report first explains the design decisions
that were made in order to implement the self-calibration routine, and then
evaluates the performance of the new motion controller by means of off-line
video tracking. The motion accuracy of the new controller is also compared with
the previously existing solution in an odor search experiment.
