Enhancing Remote Inspection With Hybrid Aerial–Terrestrial Locomotion Using a Minimalist Passive Multilegged System

The inspection capabilities of autonomous aerial vehicles (AAVs) in confined spaces face significant environmental constraints. Traditional ground locomotion solutions incorporating additional actuators increase system bulk, limiting accessibility. This research presents Multilegged Integrated Locomotion for Long-range Inspection (MILLI), a specialized AAV designed for Rail Viaduct Bearing inspection. MILLI incorporates a novel, passively engaged Klann linkage system that enables terrestrial locomotion utilizing the primary flight motors, eliminating supplementary actuators. The system facilitates seamless transitions between aerial and terrestrial modes, optimizing locomotion strategy in complex environments. The lightweight design maximizes confined space accessibility. Experimental validation through simulated and physical testing demonstrates the system's effectiveness, combining aerial mobility for space entry with efficient terrestrial navigation to inspection targets. Results confirm enhanced maneuverability and improved energy efficiency of terrestrial locomotion compared to pure aerial navigation.