Assistive Robotic Technology
The goal of this research is to develop advanced control solutions for robotic assistive devices, such as lower-limb exoskeletons, to enable them to work symbiotically with human users to achieve stable, safe, and versatile maneuvers without external interventions, and thus potentially improving the quality of life of millions. Lower-limb exoskeletons serve as assistive devices by providing support and balance to wheelchair users and enabling them to perform normal ambulatory functions and alleviate secondary health complications. The primary limitation of commercial exoskeletons is the use of rudimentary controllers that are driven by finite-state machines with extensive hand-tuned gait parameters, offering no formal guarantees of either stability or safety, and typically require the use of additional aids such as crutches to be used safely. There is, therefore, a critical need for developing advanced lower-limb exoskeleton controllers that enable enhanced locomotion for wheelchair users without the use of external supports. Specifically, we develop a unified model-based feedback control framework that efficiently mediates stability, safety, and interactive force constraints. By harnessing the power of modern optimization techniques and machine learning, our methods will provide improved and versatile mobility, including continuous walking and turning at various speeds, stair climbing, unassisted standing, and sitting, as well as dynamic whole-body balancing in place. We expect that this work has a positive impact on creating the next generation of robot wearable systems that synergize with paraplegic users to realize increased mobility, ultimately improving the overall health of millions of individuals who suffer from spinal cord injuries.
Harib, O., Hereid, A., Agrawal, A., Gurriet, T., Finet, S., Boeris, G., Duburcq, A., Mungai, M. E., Masselin, M., Ames, A. D., Sreenath, K. and Grizzle, J.
Feedback control of an exoskeleton for paraplegics: toward robustly stable hands-free dynamic walking
IEEE Control System Maganize (CSM), 2018, Vol. 38(6), pp. 61-87
Gurriet, T., Finet, S., Boeris, G., Duburcq, A., Hereid, A., Harib, O., Masselin, M., Grizzle, J. and Ames, A. D.
Towards restoring locomotion for paraplegics: realizing dynamically stable walking on exoskeletons
IEEE International Conference on Robotics and Automation (ICRA), 2018, pp. 2804-2811
Agrawal, A., Harib, O., Hereid, A., Finet, S., Masselin, M., Praly, L., Ames, A. D., Sreenath, K. and Grizzle, J. W.
First steps towards translating HZD control of bipedal robots to decentralized control of exoskeletons
IEEE Access, 2017, Vol. 5, pp. 9919-9934