Design, Analysis and Evaluation of the Hip-Driven Clutch-Type Elastic Actuator for Assisted Gait

The reduction in muscle strength in the lower limbs of elderly individuals can affect their mobility and disrupt their daily routines. Exoskeletons could provide supportive torque and facilitate the elderly in resuming normal social activities. The ideal exoskeleton should provide sufficient walking torque and maintain good human-exoskeleton coupling. We proposed a clutch-type elastic actuator (CEA) based on a ratchet pawl mechanism as the hip joint actuator, which couples the elastic energy storage element with the motor and takes advantage of the long stance phase in the assisted gait. The actuator kinetic model was established for the swing and stance phase, and simulation and bench experiments were conducted to evaluate the performance of CEA. Compared with the rigid actuator(RA), the simulation results show that the CEA reduces the peak power by 56.56% and the average power by 64.22%, the bench test shows that the CEA reduces the peak power by 47.97% and the average power by 56.33%, providing a reference for the miniaturization and lightweight design of exoskeletons.