Walking has a high priority for recovery among patients with a spinal cord injury, stroke survivors or any patient with motor disorders, irrespective of the severity of injury, time of injury, or age at the time of injury. Lower limb exoskeletons are devices that allow these people to walk again. Walking with an exoskeleton can improve their mobility and independence, and impacts their general health.
Currently, proper balance with exoskeletons is only achieved by the use of crutches. This limits its daily usage to a small range of activities where the use of hands is not needed. The ideal exoskeleton would be the one in which the user can forget they are wearing it, even when doing challenging tasks. Hence, the design of an exoskeleton should incorporate a means of naturally and robustly assisting the user with their balance. This would allow the user to stand and walk without crutches and being able to use their hands for other small actions during daily activities like picking up objects. Additionally, being able to walk on challenging terrains would extend the possibilities of the exoskeleton during daily live activities.
In this project, we focus on developing controllers to assist in balance with exoskeletons during standing and walking. We use insights in human balancing strategies for designing novel control algorithms to ensure that balance is maintained. Additionally, we also focus on safety aspects in case that balance cannot be maintained. That is, looking for safe falling strategies to perform by the exoskeleton and the user in case of a failure of the balance controller.
This raises several challenging questions: which strategies (ankle strategy, hip strategy or stepping strategy) do humans use to maintain balance in different circumstances? How can these strategies be effectively supported with an exoskeleton? Which adaptations are needed during walking on challenging terrains? How the exoskeleton should react when the balance cannot be maintained?