CAREER: Extreme Robot Walking: Speed, Agility, and Efficiency via Reduced Degrees of Freedom

This Faculty Early Career Development (CAREER) project intends to develop new legged robots that combine agility over rough terrain with speed and efficiency, enabling robots to go wherever human workers can. Robots with legs can traverse rougher terrain than wheeled vehicles and carry heavier loads for longer periods than flying drones. However, current legged robots are significantly slower and less efficient than their wheeled and flying counterparts. The hypothesis is that robot legs driven by a small number of powerful motors — similar to a car’s wheels or a boat’s propellers — can achieve higher speeds and efficiency compared to conventional robot legs powered by many smaller, less powerful motors. Achieving this goal requires new knowledge in controlling balance and steering with fewer motors, as well as investigations into efficiency, robustness, and payload capacity. The resulting robots aim to match human speed, even over long distances, to assist with tasks such as package delivery, emergency response (e.g., wildfire fighting), and scientific exploration. This project will encourage K-12 students' interest in engineering through hands-on activities with walking linkages and by providing training to expand access to the FIRST LEGO League. This CAREER project will attempt to combine a single-degree-of-freedom, linkage-based legs that recirculate in a stepping motion through continuous crank rotation with underactuated balance control algorithms based on reduced-order models to enable high-speed walking, low cost of transport, and flexible navigation over rough terrain. Investigations into passive dynamic walking and actuator coordination will focus on improving efficiency and payload capacity. Bipedal and multi-legged robot designs, along with control architectures developed around shared reduced-order models of walking locomotion, will be evaluated through simulation, physical prototyping, and hardware experiments. These efforts aim to set new records for walking robot speed and endurance. This work's improvements to the foundations of legged robot performance could enable future robot locomotion over uneven terrain for service in the home, transportation outdoors, and planetary exploration beyond. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.