How quadcopters could retain high precision near obstacles

The growth of the Micro Aerial Vehicle (MAV) industry is outpacing our understanding of how MAVs behave in cluttered environments. Search and rescue and product delivery – two key MAV applications occur in tight, confined spaces filled with complex obstacles. Our current understanding of how MAVs interact with boundaries is based primarily on helicopter models, which were designed for high Re flows. To create better flow models of MAV-boundary interactions, we measured the lift forces and wakes of small quadcopters using a load cell and Particle Image Velocimetry. We found that side-wall proximity has minimal effect on flight performance, whereas ceiling and ground proximity cause significant disruptions. To generalize our results to multi-MAV systems, we also considered two quadcopters with interfering wakes. The resulting flow models could be incorporated into MAV controllers to improve the precision of their trajectories. When MAVs operate near humans or cooperate with humans centimeter-scale precision is the only safe option. We, therefore, believe our models can help MAVs be safer and more reliable, two attributes critical to their societal acceptance.  Better flow models could also obviate the need for heavy sensors and cameras, which would free up payload on MAVs.