Luan Yipeng, Zhang Jianjun, Qi Kaicheng, Yang Gaowei
Hebei University of Technology, School of Mechanical Engineering, Department of Mechanical Engineering, Tianjin 300130, P.R.China.
Sheng Wu Yi Xue Gong Cheng Xue Za Zhi. 2020 Apr 25;37(2):324-333. doi: 10.7507/1001-5515.201908045.
In order to reduce the impact caused by the contact between the foot and the ground when wearing the lower extremity exoskeleton under the condition of high load, this paper proposed an exoskeleton foot mechanism for improving the foot comfort, and optimized the key index of its influence on the comfort. Firstly, the physical model of foot mechanism was established based on the characteristics of foot stress in gait period, and then the mathematical model of vibration was abstracted. The correctness of the model was verified by the finite element analysis software ANSYS. Then, this paper analyzed the influence of vibration parameters on absolute transmissibility based on vibration mathematical model, and optimized vibration parameters with MATLAB genetic algorithm toolbox. Finally, this paper took white noise to simulate the road elevation as the vibration input, and used the visual simulation tool Simulink in MATLAB and the vibration equation to construct the acceleration simulation model, and then calculated the vibration weighted root mean square acceleration value of the foot. The results of this study show that this foot comfort mechanism can meet the comfort indexes of vibration absorption and plantar pressure, and this paper provides a relatively complete method for the design of exoskeleton foot mechanism, which has reference significance for the design of other exoskeleton foot and ankle joint rehabilitation mechanism.
为了降低在高负荷条件下穿戴下肢外骨骼时足部与地面接触所产生的影响,本文提出了一种用于提高足部舒适性的外骨骼足部机构,并对其影响舒适性的关键指标进行了优化。首先,基于步态周期中足部受力特性建立了足部机构的物理模型,然后抽象出振动数学模型。利用有限元分析软件ANSYS验证了模型的正确性。接着,基于振动数学模型分析了振动参数对绝对传递率的影响,并利用MATLAB遗传算法工具箱对振动参数进行了优化。最后,采用白噪声模拟路面不平度作为振动输入,利用MATLAB中的可视化仿真工具Simulink和振动方程构建了加速度仿真模型,进而计算出足部的振动加权均方根加速度值。研究结果表明,这种足部舒适性机构能够满足减震和足底压力的舒适性指标,本文为外骨骼足部机构的设计提供了一种较为完整的方法,对其他外骨骼足部及踝关节康复机构的设计具有参考意义。