Wearable Gait Measurement System with an Instrumented Cane for Exoskeleton Control

Abstract

In this research we introduce a wearable sensory system for motion intention estimation and control of exoskeleton robot. The system comprises wearable inertial motion sensors and shoe-embedded force sensors. The system utilizes an instrumented cane as a part of the interface between the user and the robot. The cane reflects the motion of upper limbs, and is used in terms of human inter-limb synergies. The developed control system provides assisted motion in coherence with the motion of other unassisted limbs. The system utilizes the instrumented cane together with body worn sensors, and provides assistance for start, stop and continuous walking. We verified the function of the proposed method and the developed wearable system through gait trials on treadmill and on ground. The achievement contributes to finding an intuitive and feasible interface between human and robot through wearable gait sensors for practical use of assistive technology. It also contributes to the technology for cognitively assisted locomotion, which helps the locomotion of physically challenged people.

The control algorithm of the lower limb exoskeleton synchronous gait

“…As noted earlier many researches are devoted to the bipedal gait analysis, and the results were published in many papers [5,7,8,[20][21][22]. Both theoretical and experimental methods for locomotion study were developed.…”

“…This is due to the fact that such a movement should occur both in the sagittal and frontal planes. The kinematics of such a motion is quite complicated, so the mathematical modeling of the spatial motion of two-legged robots is presented only in several works due to considerable difficulties [1][2][3][4][5][6][7][8]21]. The mathematical description of the slow (quasi-static) gait of a human in an exoskeleton, according to our analysis, is not present anywhere.…”

Survey of On-line Control Strategies of Human-Powered Augmentation Exoskeleton Systems

“…The control algorithms ensure that the exoskeleton moves in concert with the wearer depending on interaction force between them [31][32][33]. In this paper we address a distinctive control strategies for above mentioned exoskeleton systems and the implementation with a given system to show their performance efficiency.…”

Optimizing User Integration for Individualized Rehabilitation

“…The user typically must reactively respond to the actions of the device after the user initially triggers the device on a step-by-step basis. Upperbody actions have previously been used for command triggering the next step of exoskeleton operation [22]. Ideally, controllers would be online modulate operation of the exoskeleton according to proactive user actions of the support aids to generate the most eicient (optimal) walking paterns.…”

“…Driving operation of assistive devices according to user commands for beter performance has typically involved selection of desirable user cues, tuning operational sensitivity to those cues, and facilitating heuristic learning [21]. Simple cues may allow users to invoke switch-type control to initiate operation with a mechanical trigger like a buton push [22].…”