Journal of Bionic Engineering (2022) 19:403–415 https://doi.org/10.1007/s42235-021-00132-6
A Rhythmic Motion Control Method Inspired by Board Shoe Racing for a Weight-Bearing Exoskeleton
Tianshuo Wang1 · Jie Zhao1 · Dongbao Sui1 · Sikai Zhao1 · Yanhe Zhu1
1 State Key Laboratory of Robotics and System, Harbin Institute of Technology, Harbin 150001, China
AbstractTo ensure the fexible walking of the weight-bearing exoskeleton robot, most researchers control the exoskeleton to follow the wearer’s movements and provide force to maintain the current dynamic state. However, due to the limitation of sensing information and computing power, it is difcult for the exoskeleton to provide the wearer reasonable and stable force only based on the dynamic model, especially in switching between swing phase and stance phase. Inspired by China’s traditional sport named board shoe racing, a walking control method based on the cooperation of the human and the exoskeleton is proposed in this paper for a lower-limb exoskeleton named PALExo. Under certain conditions, the exoskeleton itself can walk stably depending on the rhythm signals generated by the Central Pattern Generator (CPG). With certain initiative during walking, it can make proper adjustments according to the human movement. With the help of dynamic simulation software and Genetic Algorithm (GA), the optimized CPG parameters are obtained. Impedance control is introduced to increase the comfort of the wearer. The impedance parameters as well as the CPG parameters are tuned in real time based on feedback. The experiments were conducted with PALExo. The results demonstrate that PALExo can efectively assist the wearer walking with a 45-kg payload benefting from the proposed method.
Keywords Exoskeleton robot · Central pattern generator · Walking control method
Mechanical system of PALExo. a The DOFs arrangement of PALExo . b The composition of the exoskeleton mechanical system . c The explosive view of the exoskeleton. d The prototype with a wearer . PALExo can be mainly divided into three parts: the upper body, legs, and shoes. Each leg of the exoskeleton contains two active telescopic rods, which connect the upper body and the shoes through the hook hinge and ball hinge at the end