Abstract: Affected by the physiological and kinematic properties of the floating rotation center of the glenohumeral joint, the compatibility between the human body and the exoskeleton will directly affect the rehabilitation effect and even endanger the safety of patients in the shoulder rehabilitation based on the exoskeleton. Based on the analysis of the characteristics of the coordinated movement of the shoulder, a compact and compliant self-aligning mechanism for the shoulder joint is proposed, which can realize independent coordinated exercise of the clavicle and scapula. Then, four complete exoskeleton configurations are proposed based on the established human-machine closed chain system. Taking the dexterity of the shoulder exoskeleton motion space as the evaluation criterion, the optimal configuration is determined, and the shoulder exoskeleton prototype is designed and developed. The wear performance test results show that the interaction force of the human-machine coupling interface is reduced from 20 N and 35 N to less than 1 N during protruding and swinging. The human body's autonomous abduction trajectory coincides the corresponding point abduction trajectory of the exoskeleton well. The proposed compliant shoulder rehabilitation exoskeleton has good human-machine compatibility.

Key words: shoulder rehabilitation exoskeleton, synergy characteristic, human-machine compatibility, self-aligning mechanism, dexterity