人机共融的主动型下肢假肢分层控制策略探讨

为研究当前主动型下肢假肢控制问题的解决策略,提出了主动型下肢假肢设计和分类的通用控制框架,包括3个分层结构:上层控制器、中层控制器、底层控制器。其中,上层控制器感知运动意图;中层控制器将运动意图转换为预期的装置状态,用于底层控制器的跟踪参考;底层控制器通过反馈控制或者前馈控制计算出预期装置状态与当前装置状态的误差,驱动假肢执行这些命令,形成控制闭环。结果表明,该通用控制框架可完整阐释主动型下肢假肢的人—机—环境共融关系,明确了分层控制策略的层级任务,为未来主动型下肢假肢的发展提供了理论指导。

Hierarchical control strategy research of active lower limb prosthetic devicesbased on fusion of man machine environment

HJ1.2mm]To study the current problem solving control strategy of active lower limb prosthesis,this work proposed the state-of-the-art techniques for controlling active lower limb prosthetic devices. The general framework including high level controller, middle level controller and low level controler for the design and classify of active lower limb prosthesis is proposed. The high level controller sensor motor intention and judge the motion task through motion pattern recognition. Middle level controller converts motor intention to be the desired device state as tracking reference for the low level controller. Considering kinematics and dynamics properties, low level controller calculates the error between expected state and the current state through feedback control and feedforward control, driving prosthesis to implement control command and forming closed loop control. The results show that the general control frame can explain the human-machine-environment relationship of the active lower limb prosthesis,and clarify the hierarchical task of the stratified control strategy, which provides the theoretical guidance for the future development of the active lower limb prosthesis.