Upper Extremity Load Reduction for Lower LimbExoskeleton Trajectory Generation Using AnkleTorque Minimization
This addresses the issue of physical strain for paraplegic users of exoskeletons, though it appears incremental as it builds on existing trajectory optimization methods.
The paper tackles the problem of excessive force required by paraplegic patients using lower limb exoskeletons with crutches by proposing a gait trajectory generation algorithm that minimizes ankle torque, resulting in reduced ground reaction force on crutches as measured in experiments.
Recently, the lower limb exoskeletons which providemobility for paraplegic patients to support their daily life havedrawn much attention. However, the pilots are required to applyexcessive force through a pair of crutches to maintain balanceduring walking. This paper proposes a novel gait trajectorygeneration algorithm for exoskeleton locomotion on flat groundand stair which aims to minimize the force applied by the pilotwithout increasing the degree of freedom (DoF) of the system.First, the system is modelled as a five-link mechanism dynam-ically for torque computing. Then, an optimization approachis used to generate the trajectory minimizing the ankle torquewhich is correlated to the supporting force. Finally, experimentis conducted to compare the different gait generation algorithmsthrough measurement of ground reaction force (GRF) appliedon the crutches