PFI: AIR-TT: Preflex versus Reflex Control of a Multijoint Robotic Exoskeleton

Northern Arizona University, Flagstaff AZ

Investigators

Abstract

This PFI: AIR Technology Translation project focuses on translating a bio-inspired algorithm, based on a transformative new theory of muscle contraction, to develop safer, faster, and more maneuverable robotic exoskeletons. The bio-inspired control algorithm seeks to address significant challenges that remain in the control and development of robotic assistive devices despite recent technological advances.  The project will result in a robust control algorithm for active ankle actuation using a lower limb exoskeleton as a platform. This control algorithm has demonstrated high potential to provide robust control of ankle torque and power while walking on varied terrain. The benefits of a robust exoskeleton with ankle actuation include improved standing postural balance, increased walking speed, and improved maneuvering over varied terrain for in-home gait rehabilitation in persons with spinal cord injury when compared to the leading competing lower extremity exoskeletons in this market space.   As it translates research discovery to commercial application, this project addresses the need for lower extremity exoskeletons with active ankle actuation. The ankle joint plays a critical role in whole-body stability and forward propulsion during walking, yet no exoskeletons currently available on the market have ankle actuation or the stability and robustness required for independent and effective function at home and in the community. These limitations affect quality of life for individuals that rely on mobility assistance by hindering participation in daily activities and maintenance of physical fitness. In this project, a bio-inspired algorithm will be used to control active actuation at the ankle joints, in addition to actuation at the knee and hip joints, to explore leg coordination in standing balance, walking speed, and ambulation over complex terrain. The project will test whether the algorithm is sufficient for control of coordinated multi-joint movement, or alternatively whether reflex feedback control is also required. Personnel involved in this project, including undergraduate and graduate students, will participate in innovation, entrepreneurship, and technology translation experiences through specialized research and coursework at Northern Arizona University, as well as business and engineering internships at Ekso Bionics, Inc. In this project, Ekso Bionics, Inc. will provide a lower extremity exoskeleton and test environment for implementation of the bio-inspired control algorithm in this technology translation effort from research discovery toward commercial reality.