Path-following by a UGV-UAV Formation Based on Null Space

This paper addresses the control of a formation composed of an unmanned ground vehicle (UGV) and an unmanned aerial vehicle (UAV) using the concepts of null space control. The formation navigates in a coordinated way, with the UAV following the UGV, keeping a relative pose with respect to it, while the UGV follows a specified path. The goal is that the UAV lands on the UGV at any desired instant, a situation quite similar to the return of the UAV to a moving base after delivering a package. Null space control techniques are used in order to get more precise control on the relative pose between the robots, increasing the reliability of the landing operation. Experimental results are presented and discussed, which validate the approach proposed to accomplish the desired task.