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

健壮、柔软、轻巧、灵巧的手将成为下一代机器人的重要组成部分，这些机器人将与人类同事进行身体互动。到目前为止，能够可靠地抓取物体的欠驱动机械手(一台电机移动多个关节)在很大程度上是由设计者的独创性创造出来的，他们使用“行业诀窍”，而没有充分利用丰富的数学抓取和操纵理论。此外，对人类手和从事有用工作的机械手的解剖学研究在很大程度上是分开发展的，导致了以不同方式表达的相似结论。工程学和医学系之间的这种合作努力将有助于弥合这些差距。工程学研究生和住院医生将定期互动；这将有助于将知识和经验跨越这两个学科的界限，从而培养解决复杂、多方面生物工程问题的能力。该项目的一个主要贡献将是对弹性驱动系列的理论描述，该系列将把单个执行器的运动映射到日常生活任务中的关键运动。作为这项工作的另一项成果，机器人手将作为未来实验的强大平台(例如，在手势研究、听力障碍者的交流和触觉探索中)，它也将有助于评估和可视化潜在的体外手术干预的效果。作为国际机器人协会重要的教育和研究工具，这只手将被用来教育和感兴趣大学和K-12的学生对机器人技术。PI团队将与学生团体和美洲原住民社区组织协调，招募合格的未被充分代表的少数族裔参与该项目。从单执行器到多指灵巧机器人手的设计并不简单，多年来一直困扰着研究人员；它将需要有原则的正式处理。在单执行器手中，在传动系中添加弹簧可以改善手的性能；精确的弹簧特性并不重要。在多执行器柔顺手的一般情况下，简单地增加一个弹簧是不够的，需要具有特定特性的多维弹簧。我们将使用多端口电路理论、材料力学、线性代数和一般多指抓取理论中的元素来理解这种多维弹簧的行为。PI的方法是将这个问题分解为子问题，大大简化了分析。还有一个问题是，一只动作不足的手应该能够执行哪些动作；PI认为，完全的手指个性化并不是必要的，相反，耦合的手指动作应该与人类执行任务时使用的动作相对应。对正常人和那些接受过手术干预的人的解剖学分析将被用来确定基本的人体运动基元的优先顺序。结合新的柔顺抓取理论，欠驱动手合成将被描述为一个参数拟合问题。手术干预对人类手的影响的详细评估，人体解剖学的研究，多端口电路模型的研究，以及对柔顺机构和线性代数基本子空间的考虑，都将被混合在一起。总而言之，这将导致一种合成弹性驱动链的方法，该方法将致动器的贡献映射到手指的有用、协调的运动中。柔顺驱动理论的含义将在机构综合和把握稳定性的上下文中进行检验，并将在实验中进行评估。研究人员将在一只能够执行日常生活中最常见任务的功能拟人化的手中，一直追寻这条推理路线，直到实现。

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.