Design and control of a lower limb exoskeleton for robot-assisted gait training

Article type: Research Article

Authors: Beyl, Pieter | Van Damme, Michaël | Van Ham, Ronald | Vanderborght, Bram | Lefeber, Dirk

Affiliations: Department of Mechanical Engineering, Vrije Universiteit Brussel, Brussels, Belgium

Note: [] Corresponding author. Email: [email protected]

Abstract: Robot-assisted rehabilitation of gait still faces many challenges, one of which is improving physical human-robot interaction. The use of pleated pneumatic artificial muscles to power a step rehabilitation robot has the potential to meet this challenge. This paper reports on the development of a gait rehabilitation exoskeleton with a knee joint powered by pleated pneumatic artificial muscles. It is intended as a platform for the evaluation of design and control concepts in view of improved physical human-robot interaction. The design was focused on the optimal dimensioning of the actuator configuration. Safety being the most important prerequisite, a proxy-based sliding mode controller (PSMC) was implemented as it combines accurate tracking during normal operation with a smooth, slow and safe recovery from large position errors. Treadmill walking experiments of a healthy subject wearing the powered exoskeleton show the potential of PSMC as a safe robot-in-charge control strategy for robot-assisted gait training.

Keywords: robot-assisted gait rehabilitation, powered exoskeleton, compliant actuator, proxy-based sliding mode control

DOI: 10.1080/11762320902784393

Journal: Applied Bionics and Biomechanics, vol. 6, no. 2, pp. 229-243, 2009