基于人机工作空间紧凑匹配的康复机构拓扑尺度融合设计方法研究

Rehabilitation robot is a popular research area in the field of robotics nowadays. As the characteristic skeleton and motion executor of rehabilitation robot, mechanical performance of mechanism is a key factor that affects the overall quality of rehabilitation robot. The existing rehabilitation mechanism designs have several problems such as inadequate human-robot compatibility, complex structures and high demand on control system performance, which have limited the real-life application of rehabilitation robot. The development of compact-workspace rehabilitation mechanisms can meet the requirements of agreeable human-robot compatibility, lightweight design and affordability. This research proposal advocates a new approach to integrated topology and dimensional synthesis of mechanisms via compact matching of human-mechanism workspace. With the employment of dual quaternion theory in Clifford algebra, the problem of compact matching between rehabilitation motion and mechanism workspace can be converted into the optimal fitting problem between point cloud and manifolds in Clifford space; meanwhile, various motion performance requirements and constraint conditions arising in the rehabilitation process are integrated into the fitting process through a unified mathematical model in order to realize the global optimization of the mechanism; furthermore, the design of workspace-reconfigurable mechanism that enables the whole-process rehabilitation can be achieved. The research results can provide theoretical support for the design of high-quality/low-cost rehabilitation mechanisms and therefore contribute to the popularization of rehabilitation robots, and enhance the completeness and practicability of the theory of mechanism synthesis.

康复机器人是当前机器人技术领域的研究热点之一，机构作为康复机器人的特征骨架和执行器，其机械性能是影响康复机器人整体品质的重要因素。现有康复机构产品设计存在人机融合性不强、结构复杂、控制难度大等问题，限制了其推广应用。研发具有紧凑工作空间的康复机构，可满足人机融合性好、轻量化设计及经济实用的要求。本项目提出基于人机工作空间紧凑匹配的机构拓扑尺度融合设计方法，以Clifford代数的对偶四元数理论为工具，将康复训练运动范围与机构工作空间的紧凑匹配问题转化为Clifford空间中点云与流形曲面的最优拟合问题，同时对康复训练中面临的多种运动性能要求与约束条件进行统一建模处理，实现康复机构设计过程的全局最优，并在此基础上实现适用于全过程康复训练的可变工作空间机构设计。本项目成果可为高品质低成本康复机构的设计提供理论支持，促进康复机器人的大众化普及与生活化应用，有利于增强机构综合理论的完备性和实用性。

在国家自然科学基金青年项目资助下，本项目以开发具有人机工作空间紧凑匹配的康复机构设计方法为目标,基于运动映射理论中的Clifford代数对偶四元数为工具，针对平面、球面和空间机构的拓扑尺度融合设计问题展开研究，将其应用于单/少自由度康复机器人机构设计，使机构综合理论有更强的实用性，并基于理论研究成果开发了康复机器人机构设计软件，研制了末端式下肢康复机器人物理样机，开展了健康受试者的试验应用。本项目的主要贡献包括：采用对偶四元数建立了基于运动几何约束统一表达的平面，球面和空间运动链拓扑尺度融合设计方法；采用运动映射理论中的傅里叶描述子建立了面向复杂运动几何约束获取的平面机构综合方法，进一步扩展了可用于机构设计的运动几何约束类型；构建了兼顾目标运动位姿匹配和满足实际工程约束条件的机构拓扑尺度融合设计方法；建立了面向可变工作空间的机构综合方法,可使机构在实际工作中进行单/少自由度切换；基于以上理论开发了面向移动终端使用的计算机辅助康复机构设计软件系统，使用者可通过移动设备摄像头方便快捷地采集自身肢体运动轨迹并通过该软件系统进行人机工作空间匹配的康复机构快速设计与仿真。以上研究成果可为高品质低成本康复机器人的设计提供理论支持，有利于增强机构综合理论的完备性和实用性。