NRI: Multi-Digit Coordination by Compliant Connections in an Anthropomorphic Hand

坚固、柔软、轻便、灵巧的手将是下一代与人类同事进行身体互动的机器人的关键组成部分。迄今为止，能够可靠地抓取物体的欠驱动机器人手（一个马达驱动多个关节）主要是由设计师利用“行业技巧”创造出来的，而没有充分利用数学抓取和操作理论的财富。此外，对从事有用工作的人手和机器人手的解剖研究在很大程度上是分开发展的，这导致了以不同方式表达的类似结论。工程系和医学院之间的合作将有助于弥合这些差距。工程研究生和住院医生将定期互动；这将有助于跨越这两个学科的边界转化知识和经验，从而培养解决复杂的，多方面的生物工程问题的能力。该项目的一个关键贡献将是对弹性传动系统的理论描述，该系统将单个驱动器的运动映射到日常生活任务中的关键动作。作为这项工作的另一个成果，机器人手将为未来的实验提供一个强大的平台（例如，在手势、听力障碍交流和触觉探索的研究中），它也将有助于评估和可视化潜在手术干预的体外效果。作为PI机构的重要教育和研究工具，这只手将用于教育大学和K-12学生对机器人技术的兴趣。PI团队将与学生团体和印第安人社区组织协调，招募合格的未被充分代表的少数民族参与该项目。从单致动器到多致动器的多指灵巧机械手设计并不简单，多年来一直困扰着研究人员；这需要有原则的正式处理。在单致动器的手，增加一个弹簧传动系统改善手；确切的弹簧特性并不重要。在一般情况下，多致动器柔顺手仅仅增加一个弹簧是不够的；需要一种具有特定特性的多维弹簧。多端口电路理论、材料力学、线性代数和一般多指抓取理论的基本概念将被用来理解这种多维弹簧的行为。PI的方法是将这个问题分解成子问题，大大简化了分析。还有一个问题是，一只未受驱动的手应该能够完成哪些动作；PI认为，完全的手指个性化是没有必要的，相反，耦合的手指运动应该与人类执行任务时使用的动作相对应。对正常人和接受过手术干预的人的解剖分析将用于确定基本人体运动原语的优先级。结合新的柔性抓取理论，将欠驱动手综合表述为一个参数拟合问题。详细评估手术干预对人手的影响，人体解剖学的研究，多端口电路模型，以及考虑柔顺机制和线性代数的基本子空间都将混合在一起。综上所述，这将产生一种合成弹性传动系统的方法，该方法将致动器的贡献映射到有用的、协调的手指运动。柔性驱动理论的意义将在机构综合和抓取稳定性背景下进行研究，并将进行实验评估。研究人员将沿着这条推理路线，一直到在一只能够执行日常生活中最常见任务的拟人化手中实现这一功能。

Robust, soft, lightweight, dexterous hands will be a crucial component of the next generation of robots that physically interact with human co-workers. To date, under-actuated robot hands (where one motor moves multiple joints) that grasp objects reliably have been created largely by designer ingenuity using "tricks of the trade" without fully capitalizing on the wealth of mathematical grasping and manipulation theory. Moreover, anatomical studies of the human hand and robotic hands that do useful work have largely evolved separately, leading to similar conclusions expressed in a different way. This collaborative effort between engineering and medical faculty will help bridge these gaps. Engineering graduate students and medical residents will interact regularly; this will serve to translate knowledge and experience across the boundaries of these two disciplines, thereby fostering the ability to solve complex, multi-faceted bioengineering problems. A key contribution of this project will be a theoretical description of an elastic drive train that maps individual actuator motions to key movements in tasks of daily living. The robotic hand produced as another outcome of this work will serve as a robust platform for future experimentation (for example, in studies on gesturing, communication for the hearing impaired, and tactile exploration), and it will also be useful for evaluating and visualizing the effect of potential surgical interventions ex vivo. An important educational and research tool in the PI's institution, this hand will be used to educate and interest university and K-12 students in robotics. The PI team will coordinate with student groups and Native American community organizations, to recruit qualified underrepresented minorities to participate in the project.Moving from single- to multi-actuator multi-fingered dexterous robot hand design is not straightforward and has frustrated researchers for several years; it will require a principled formal treatment. In single-actuator hands, adding a spring to the drive train improves the hand; the exact spring characteristics are not critical. In the general case of multi-actuator compliant hands simply adding a spring is not enough; a multidimensional spring of specific characteristic is needed. Concepts from multiport circuit theory, mechanics of materials, linear algebra and elements of general multi-fingered grasping theory will be used to understand the behavior of such a multi-dimensional spring. The PI's approach is to break this problem into sub-problems, greatly simplifying the analysis. There is also the matter of which actions an under-actuated hand should be able to perform; the PI argues that complete finger individuation is not necessary, rather coupled finger movements should correspond to those used by humans to perform tasks. Anatomical analysis of both normal humans and those that have undergone surgical intervention will be used to prioritize basic human motion primitives. Combined with the novel compliant grasping theory, under-actuated hand synthesis will be formulated as a parameter fitting problem. Detailed evaluation of the effects of surgical intervention on the human hand, the study of human anatomy, multi-port circuit models, and consideration of compliant mechanisms and the fundamental subspaces of linear algebra will all be blended. Taken together, this will result in a method to synthesize an elastic drive train that maps actuator contributions to useful, coordinated motions of the fingers. Implications of the compliant actuation theory will be examined in the mechanism synthesis and grasp stability contexts, and these will be evaluated experimentally. The investigators will pursue this line of reasoning all the way to implementation in a functioning anthropomorphic hand capable of performing the most common tasks of everyday life.