Analysis of Underactuated Hand Exoskeletons with Elastic Structures

Mechanical and Electronic Control Engineering, Beijing Jiaotong University, Beijing, China

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Abstract

Hand exoskeletons have broad application prospects in rehabilitation medicine, industrial assistance, and daily walking aids. Underactuated systems are popular due to their simple structure and low cost. However, existing designs lack adaptive ability when facing objects of different sizes and lack an effective mechanism to realize autonomous adjustment of grasping posture and force. The kinematics model is established and simulated by the vector closed-loop method. The static model is established based on Hooke’s law. The relationship between the grasping force and the spring deformation is derived, and the target grasping force of 10N is set. The results show that the metacarpophalangeal joint (MCP) Angle is stable in the safe range of -65° to 4°, and the structure can autonomously adjust the grasping posture and force distribution to improve adaptability. The results show that the structure can automatically adjust the grasping posture and force distribution according to the characteristics of the object, and effectively improve the grasping stability and adaptability. This design provides a feasible technical path for the intelligence and practicability of the underactuated hand exoskeleton