Lower limb energy storage assisted exoskeletons realize walking assistance by using the energy stored by elastic elements during walking. Such exoskeletons are characterized by a small volume, light weight and low price. However, energy storage assisted exoskeletons adopt fixed stiffness joints typically, which cannot adapt to changes of the wearer's height, weight, or walking speed. In this study, based on the analysis of the energy flow characteristics and stiffness change characteristics of lower limb joints during a human walking on flat ground, a novel variable stiffness energy storage assisted hip exoskeleton is designed, and a stiffness optimization modulation method is proposed to store most of the negative work done by the human hip joint when walking. Through the analysis of the surface electromyography signals of the rectus femoris and long head of the biceps femoris, it is found that the muscle fatigue of the rectus femoris is reduced by 8.5% under the optimal stiffness assistance condition, and the exoskeleton provides better assistance under the optimal stiffness assistance condition.

被动储能助力外骨骼充分利用人体自身能量,减少人行走时的能耗.针对目前被动储能助力外骨骼多采用定刚度关节,在分析人行走过程中关节能量流动特性及刚度变化特点的基础上,设计了一种被动变刚度储能助力髋关节外骨骼,建立了人一外骨骼耦合模型,仿真得到人体在平地上步行功耗最小的最优刚度,以及在变刚度条件下人体总功耗、大腿主要肌肉肌力变化.研究结果表明:外骨骼的不同刚度会影响穿戴者行走过程中的能耗,在下肢屈曲和伸展过程中分别采用最优刚度,可进一步减少人体能耗.该结果对被动外骨骼设计中的刚度需求具有重要参考意义.

柔顺变刚度驱动机构分为弹性元件、气动元件、电-磁元件和智能材料四大类.变刚度驱动机构正在逐步应用于康复机器人,在上下肢康复机器人中可适应患者的阻抗变化,在外骨骼中可保证穿戴者的安全,在假肢中可提高仿生性.现有康复机器人变刚度驱动机构还存在一些问题,还应具备紧凑的结构、低能耗、良好的刚度特性、高响应速率和渐进式输出扭矩曲线等特点.

Aiming at the demand of charging automation of electric vehicles, a charging robot end passive compliant mechanism based on Stewart parallel mechanism is designed based on the analysis of the requirements of electric vehicle charging plug and socket docking in this paper. The position and attitude deviation adaptability of the compliant mechanism under various deviation conditions are simulated,and a test platform is built by using a robot arm, and the docking experiments are carried out. The research results show that the passive compliant mechanism can meet the demands of reliable docking and has an inserting force less than 100 N in the case of large deviation.