Collaborative object picking and delivery with a team of micro aerial vehicles at MBZIRC

Abstract

Picking and transporting objects in an outdoor environment with multiple lightweight MAVs is a demanding task. The main challenges are sudden changes of flight dynamics due to altered center of mass and weight, varying lighting conditions for visual perception, and coordination of the MAVs over unreliable wireless connections. At the Mohamed Bin Zayed International Robotics Challenge (MBZIRC) teams competed in a Treasure Hunt where three MAVs had to collaboratively pick colored disks and drop them into a designated box. Only little preparation and test time on- site required robust algorithms and easily maintainable systems to successfully achieve the challenge objectives. We describe our multi-robot system employed at MBZIRC, including a lightweight gripper, a vision system robust against illumination and color changes, and a control architecture allowing to operate multiple robots safely. With our system, we-as part of the larger team NimbRo of ground and flying robots-won the Grand Challenge and achieved a third place in the Treasure Hunt.