Exploiting the Line Virtual Structure Formation for Cooperation of Two Mobile Robots

This work explores further the problem of controlling a formation composed by two unmanned aerial vehicles (UAVs), or by a UAV and an unmanned ground vehicle (UGV), using the virtual structure paradigm, having the line connecting the two robots as the virtual structure. An alternative version for characterizing the virtual structure is proposed, and the advantages and drawbacks of this novel framework are discussed. The proposed formation controller generates references for the time variation of the formation variables in the formation space, which are transformed to velocities in the robots space, dynamically compensated using the feedback linearization technique. To validate our proposal experiments are run, considering one quadrotor and one differential drive wheeled mobile robot. The obtained results are presented through illustrations and videos, providing examples of the advantages of the proposed formation characterization.