驱动支链完全解耦的可重构踝关节康复并联机构型综合

Type Synthesis of Reconfigurable Parallel Mechanisms for Ankle Rehabilitation with Completely Decoupled Actuated Limb

基于术后6~12周内的前、中、后期踝关节扭伤的康复运动需求,提出具有三种康复运动模式的可重构踝关节康复并联机构。首先,针对胫距关节和距下关节的轴线运动特征,研究踝关节康复运动切换机理和“双心”特性,提出符合踝关节自由度和轴线运动特性的六种融合支链;根据构型约束支链的选取方案,筛选出四种无约束支链。其次,基于旋量理论对六种融合支链进行过约束设计,验证符合实际需求的融合支链;根据传递力旋量与动平台运动轴线关系,提出一种驱动支链完全解耦优化方法,得到三种无约束驱动支链以及十二种机构构型,使得机构在三种康复模式中实现完全解耦。最后,通过ADAMS仿真验证机构的三种运动分支及完全解耦的正确性。可重构踝关节康复机器人依据患者康复需求采取对应康复模式,适用范围广,针对性强,控制简单。

Reconfigurable ankle rehabilitation parallel mechanisms with three rehabilitation motion modes are proposed in terms of the movement requirements of rehabilitation for ankle sprain in the anterior-middle-posterior periods within 6-12 weeks after surgery.First, according to the axis motion characteristics of tibiotalar joint and subtalar joint, the motion switching principle and double-point characteristic of ankle rehabilitation are investigated, and six LBAs(limbs of the bio-syncretic axis) are given to satisfy the DOF and axis motion characteristics of the ankle joint. Four kinds of unconstrained limbs are enumerated through the selected scheme of the configuration constrained limbs. Second, over-constrain design of six LBAs are carried out based on the screw theory to verify LBAs that meet the practical movement requirements. According to the relationship between the transmission force screw and the motion axes of the platform, a completely decoupling optimization method is proposed, and three unconstrained driving limbs and twelve of mechanism configurations are obtained, which made the mechanism completely decoupled in all three rehabilitation modes. Finally,the correctness of the three limbs of the mechanism and the completely decoupling is verified through ADAMS simulation.Reconfigurable ankle rehabilitation robot is adopted the corresponding rehabilitation modes according to the patient’s rehabilitation conditions, with a wider application range, stronger pertinence, and simple control.