On-line walking speed control in HUman-powered exoskeleton systems

Abstract

The on-line walking speed control in human-powered exoskeleton systems is a big challenge, the real-time translations of human intention to increase or decrease walking speed in maneuverable coupled human exoskeleton systems is still complex field. An adaptive trajectory frequency control algorithm has been developed to guide the exoskeleton's joint in HUman-powered Augmentation Lower Exoskeleton (HUALEX) within the human wearer intended speed. Based on mismatch of Dual Reaction Force (DRF) sensors, we proposed a new control methodology for walking speed control. Human intention recognition and identification through instrumented footboard and smart shoe is achieved successfully in this work, the new term heel contact time H CT is main feedback for control algorithm. Adaptive Central Pattern Generators (CPGs) used to control joint trajectory frequency, the different walking speeds associated with different functioning of human body CPGs frequency. From the experimental walking trails we designated the walking speed transition threshold to be ±74ms depends on the pilot's body dimension. Experiments on one Degrees of Freedom (1-DOF) platform are demonstrated for walking speed control scheme validation.