Type Synthesis of Parallel Mechanisms with Automatically Adjustable Center for Ankle Rehabilitation

doi:10.3901/JME.2025.05.153

Abstract

Abstract: Most of the existing ankle rehabilitation mechanisms are passive rehabilitation models, generally suitable for early rehabilitation. At the same time, existing rehabilitation mechanisms suffer from poor human-robot compatibility and are not suitable for the middle and late stages of rehabilitation. A new type synthesis method of ankle rehabilitation mechanisms with self-adjustable center for various rehabilitation stages is proposed. A series of new configurations of ankle rehabilitation mechanisms with multiple rehabilitation modes and a self-adjustable center are synthesized. First, based on the kinematics of the human ankle, the (3PS)_H branch equivalent to the human ankle motion is given. Then, the 3R mechanism containing human ankle joint is constructed by adding the 3R mechanism on the basis of the (3PS)_H branch. The intersection of the branch of the above mechanism close to the fixed platform and the kinematics pair of the 3TnR mechanism close to the moving platform is taken to obtain the ankle rehabilitation mechanism suitable for early rehabilitation. Finally, the three translation drives of the above mechanism are reconfigured to become three passive kinematics pairs, so that the center of rotation of the ankle can be automatically compensated by the three translation mechanisms. Ankle rehabilitation mechanisms with a self-adjustable center for middle and late stages of rehabilitation have been obtained. The correctness of the DOF and self-adjustment of the rehabilitation mechanism is verified. This provides a configuration basis for the design of an ankle rehabilitation robot with multiple rehabilitation modes and self-adjustable center in the future.

Key words: automatic adjustable center, parallel mechanism, ankle rehabilitation, multiple rehabilitation modes, type synthesis

CLC Number:

TH112

WANG Sen, LI Bing, PENG Fujun. Type Synthesis of Parallel Mechanisms with Automatically Adjustable Center for Ankle Rehabilitation[J]. Journal of Mechanical Engineering, 2025, 61(5): 153-164.

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