Design on electrohydraulic servo driving system with walking assisting control for lower limb exoskeleton robot. (26th February 2021)

• Record Type: Journal Article
• Authors: Wang, Buyun; Liang, Yi; Xu, Dezhang; Wang, Zhihong; Ji, Jing
• Is Part Of: International journal of advanced robotic systems. Volume 18:Number 1(2021)
• Publication Date: 2021-02-26
• Subjects: Lower limb exoskeleton robot -- articular locomotion -- electrohydraulic servo driving -- PID control -- tracking error estimation and pressure compensation; Robotics -- Periodicals; Robotics; Periodicals; 629.892
• DOI: 10.1177/1729881421992286
• Languages: English
• ISSNs: 1729-8806

Abstract

According to the characteristics of human gait and the requirements of power assistance, locomotive mechanisms and electrohydraulic servo driving are designed on a lower limb exoskeleton robot, in which the miniaturization and lightweight of driving system are realized. The kinematics of the robot is analyzed and verified via the typical movements of the exoskeleton. In this article, the simulation on the power of joints during level walking was analyzed in ADAMS 2016, which is a multibody simulation and motion analysis software. Motion ranges and driving strokes are then optimized. A proportional integral derivative (PID) control method with error estimation and pressure compensation is proposed to satisfy the requirements of joints power assistance and comply with the motion of human lower limb. The proposed method is implemented into the exoskeleton for assisted walking and is verified by experimental results. Finally, experiments show that the tracking accuracy and power-assisted performance of exoskeleton robot joints are improved.