Hemispherical InfraRed (IR) Marker for Reliable Detection for Autonomous Landing on a Moving Ground Vehicle From Various Altitude Angles

Autonomous landing of a quadrotor aerial vehicle on a mobile ground vehicle is a key function required for heterogeneous cooperation between air and ground vehicles to extend mission range. Wide angle detection and localization of mobile landing spot can improve reliability and convenience in autonomous landing processes. In this study, we present a hemispherical InfraRed (IR) marker designed and built for reliable detection and autonomous landing from various altitude angles. IR light has higher transmittance and the hemispherical design provides wide angle radiation. We present the fabrication process of the hemispherical marker from a planar flexible film, followed by full system integration on the ground vehicle. The relatively compact (radius: 2.25 cm, height: 2.3 cm) marker is detectable from wide altitude angles (0–180°) and detectable even when covered by thin foreign objects such as fallen leaves or plastic bags. Outdoor experiments with full system integrating autonomous air and ground vehicles demonstrated the feasibility of this approach to autonomous landing for heterogeneous cooperation.