舱外航天服上肢主动助力外骨骼建模与仿真

Modeling and Simulation of Active Upper Limb-assisted Exoskeleton in Extravehicular Spacesuit

目的为消除舱外航天服关节阻尼力矩对航天员舱外作业的影响,设计一种舱外航天服主动助力上肢外骨骼方案。方法上肢外骨骼关节采用串联弹性体(rotary series elastic actuator,RSEA);分别建立人体和航天服间接触力、舱外航天服关节阻尼、上肢外骨骼动力学模型;按照人在回路控制系统原理,提出关节力控制策略和外骨骼力控方法,并进行仿真实验。结果仿真表明:助力外骨骼可将航天服肩关节阻尼力矩从39.5Nm减小到0.45Nm,可将肘关节阻尼力矩从9.8Nm减小到0.1Nm。结论该舱外航天服上肢主动助力外骨骼能够显著减少人体受到的阻尼力矩,有利于降低航天员体力消耗,延长舱外作业时间。

Objective To eliminate the influence of joint damping torque on the operation of astronauts,an active assistant upper-limb exoskeleton scheme for extravehicular spacesuit was designed.Methods The rotary series elastic actuator(RSEA)was adopted as the upper-limb extremity exoskeleton joints and the contact force model between human body and spacesuit,joint damping model of extravehicular spacesuit and the dynamics model of upper extremity exoskeleton were established respectively.According to the principle of human in loop control system,joint force control strategy and exoskeleton force control method were proposed and simulated.Results The simulation validated that the damping torque of the shoulder joint was reduced from 39.5 Nm to 0.45 Nm and the damping torque of the elbow joint was reduced from 9.8 Nm to 0.1 Nm.Conclusion Active exoskeleton of spacesuit can significantly reduce the damping torque imposed upon the human body by the spacesuit joint,thus reducing the physical consumption of astronauts and prolonging the outer space working time.