Human-Guided Robotic Exoskeleton Cooperative Walking for Climbing Stairs

Abstract

This paper proposes a novel human-cooperative control strategy for robotic exoskeleton to help humans climbing stairs without crutches. The trajectory of the center of gravity (CoG) is planned using the dual length linear inverted pendulum model (DLLIPM) and virtual slope method (VSM) in the sagittal plane (SP) and coronal plane (CP) to deal with two zero-moment point (ZMP) problems in stairs. Then, the climbing workspace is divided into a human region, where the human is more dominant in the manipulation, and a robot region, where the robot plays a more active role in the manipulation task. The proposed method increases the flexibility of human-robot physical interaction and makes good use of the advantages of humans and robots. An adaptive torque controller is applied to solve the problem of dynamic model parameter uncertainty. Finally, three volunteers are invited to participate in the validation of the system and the experimental results demonstrate the effectiveness of the exoskeleton.