人服系统上肢交互生物力学仿真模型

目的 通过建立人-舱外服上肢交互生物力学仿真模型计算穿着舱外服后航天员上肢关节力矩和肌肉力，满足出舱活动风险评估的需求。方法 分别建立舱外服手臂的刚体运动学模型和关节阻尼力矩迟滞模型以描述舱外服关节的运动和力学特性。通过对舱外航天服肘部和人体肘部位置进行约束实现人体和舱外服手臂之间的运动学耦合，利用虚拟反作用力元实现两者之间的动力学耦合，在反向运动生物力学架构下建立一体化仿真模型。利用该模型对宇航员穿着加压、未加压舱外服和不穿着舱外服3种工况下肘弯曲/伸展进行仿真案例分析。结果 3种工况下肱二头肌的预测肌肉激活和积分肌电的相关性分别为0.86、0.71、0.65，肱三头肌对应的相关性分别为0.75、0.61、0.60，采用预测肌肉激活和积分肌电的一致性定性验证了模型的正确性，利用舱外服肘关节阻尼力矩与人体肘关节肌肉承受力矩之间的一致性验证了模型的合理性。结论 该人服系统上肢交互生物力学仿真模型能有效计算航天员穿着舱外服后的上肢关节力矩和肌肉力，且仿真结果和实验表明，加压后舱外服关节阻尼力矩造成较大的人体关节力矩和肌肉负荷，为航天员出舱活动中的体力负荷和骨肌风险评估提供方法学支撑。

Biomechanical simulation model of upper limb interaction for human-spacesuit system

Objective To calculate joint torques and muscle forces of astronaut in spacesuit by establishing the biomechanical simulation model of upper limb interaction for human-spacesuit system, so as to assess the risk in extra-vehicular activities. Methods For spacesuit upper limb, the kinematic model of rigid body rotation and hysteresis model of joint resistant torque were built, respectively, to describe the kinematic and dynamic features of spacesuit joints. Kinematic coupling of human and spacesuit upper limb was fulfilled by restricting the displacement between spacesuit elbow and human elbow, and dynamic coupling was fulfilled by using virtual reaction element. An integrated simulation model was established in the framework of inverse sport biomechanics. With this model, the elbow flexion/extension of the astronaut under pressure-suited, unpressured-suited and unsuited condition was simulated for case study. Results The correlation coefficients of predicted muscle activation and iEMG for biceps under the three conditions were 0.86, 0.71 and 0.65, respectively; the corresponding correlation coefficients for triceps were 0.75, 0.61 and 0.60, respectively. The consistency between predicted muscle activations and surface electromyography collected in experiment qualitatively validated the accuracy of this model, and the consistency between human elbow joint torque working on muscles and spacesuit elbow joint resistant torque validated the rationality of the model. Conclusions The established biomechanical simulation model of upper limb interaction for human-spacesuit system can effectively calculate the joint torque and muscle force of astronaut in spacesuit. The simulation and experiment results indicate that joint resistant torque in pressured spacesuit has great influence on human joint torque and muscle workload, which offers methodological support for physical workload and musculoskeletal risk evaluation for astronauts in extra-vehicular activity.