基于人机闭链的下肢康复外骨骼机构运动学分析

针对下肢康复外骨骼在使用过程中出现的运动偏差,基于人体-外骨骼运动模型与调整模型,完成了下肢康复外骨骼的结构设计与运动学分析。运用人机偏差变量理论和人机相容理论,在人体-外骨骼运动模型上添加被动自由度,建立了人体-外骨骼调整模型。根据2种模型设计了下肢康复外骨骼,该外骨骼提供运动模式和调整模式,可通过人机滑动偏差检测装置切换使用模式。通过建立单侧外骨骼机械腿运动学模型,求解其运动方程和连杆变换矩阵。运用MATLAB和ADAMS软件对外骨骼模型和人体-外骨骼模型进行运动学仿真,并对比分析仿真结果。结果表明:下肢康复外骨骼在矢状面内的运动空间可以覆盖人体末端运动轨迹,该外骨骼各关节仿真运动趋势与理论运动趋势基本一致;调整模式能够补偿运动模式产生的运动偏差,验证了下肢康复外骨骼机构设计的合理性。研究表明基于人机闭链设计的下肢康复外骨骼机构能够较好地补偿运动偏差,避免因人机滑动引起的人体二次损伤,为外骨骼的实用化设计与研究提供了理论基础。

Kinematics analysis of lower limb rehabilitation exoskeleton mechanism based on human-machine closed chain

Aiming at the motion deviation in the use of lower limb rehabilitation exoskeleton, the structure design and kinematics analysis of a lower limb rehabilitation exoskeleton was completed based on the human-exoskeleton movement model and adjustment model. Firstly, using the theory of human-machine deviation variable and the theory of human-machine compatibility, the human-exoskeleton adjustment model was established by adding the passive degree of freedom to the human-exoskeleton movement model. Based on the human-exoskeleton movement model and the human-exoskeleton adjustment model, the lower limb rehabilitation exoskeleton was designed. The lower limb rehabilitation exoskeleton provided movement mode and adjustment mode, which could be switched by the sliding deviation detection device of the human-machine. The kinematics model of single lateral exoskeleton mechanical leg was established, and the motion equation and the linkage transformation matrix were solved. The MATLAB and ADAMS software were used to simulate the exoskeleton model and the human-exoskeleton model, the simulation results were compared and analyzed. The results showed that the moving space in the sagittal plane of the exoskeleton could cover the end trajectory of the human body. The movement trend and theoretical movement trend of the exoskeleton joints were basically consistent, and the adjustment mode compensated the motion deviation of the movement mode,which proved the rationality of the lower limb rehabilitation exoskeleton. The lower limb rehabilitation exoskeleton mechanism based on human-machine closed chain can compensate the motion deviation and avoid the secondary damage. It can be used for reference in the practical design of exoskeleton, and provides a theoretical basis for exoskeleton mechanism research.