CAREER: Utilizing Physical Interactions to Improve Legged Mobility on Challenging Terrains

University Of Southern California, Los Angeles CA

Investigators

Abstract

This Faculty Early Career Development (CAREER) award supports research that will create new methods to allow legged robots to utilize physical interactions to achieve high mobility on complex natural terrains. Robots are becoming increasingly better when moving on rigid, flat ground, but still struggle to move through soft sand, sticky mud, and rubble piles, limiting their capabilities in critical missions such as search and rescue, delivery, and explorations. The insights and new methods from this work will enable the development of next generation robots that can actively “harvest” environment interaction forces, or even large disturbances, to generate agile movements. This capability can significantly reduce robot control effort and computational complexity in challenging environments, and therefore empower legged robots for a broader range of applications important for national health, prosperity, and welfare, such as environment monitoring, earthquake rescue, and planetary exploration. Additionally, by translating part of this research into tangible education activities, this project will integrate classroom, laboratory, and real-world application experiences to inspire and engage a diverse group of students from middle school through graduate levels to form the next generation of engineers and scientists. Legged locomotion on natural deformable terrains is fundamentally challenging due to our limited understanding of the complex terrain responses. Upon robot leg contact, sand and soil can deform and flow like a fluid, or jam like a solid, while loosely embedded rocks and boulders can slide or rotate, causing robots to slip, stuck, or even flip over. To overcome this challenge, this research will integrate locomotion experiments, granular physics theory, and dynamical systems methods, to determine how intrinsic terrain properties and leg-terrain contact modes influence terrain responses and the resulting robot locomotion dynamics. This new knowledge will allow robots to incorporate predicted terrain forces as part of their locomotion control, to produce desired dynamics across different environments. Terrain force predictions will be validated by laboratory experiments, and the robot locomotion performance will be evaluated in both laboratory experiments and field testing at White Sands, NM. This project is supported by the cross-directorate Foundational Research in Robotics program, jointly managed and funded by the Directorates for Engineering (ENG) and Computer and Information Science and Engineering (CISE). 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.