Cable-Driven Parallel Manipulators with Extensible Rods

带可伸缩杆的电缆驱动并联机械手

• 批准号: RGPIN-2017-04248
• 负责人: Carretero, Juan
• 金额: $ 1.6万
• 依托单位: University of New Brunswick
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2019
• 资助国家: 加拿大
• 起止时间: 2019-01-01 至 2020-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=678611
• 关键词: Cable; Driven; Parallel; Manipulators; Extensible

Redundancy of different types in the context of serial manipulators has reached a good level of maturity over the years. Most notably, kinematic redundancy (i.e., adding more joints and links than those strictly required by the task) for better kinematic performance or obstacle avoidance has been the focus of a number of works and successful manipulator designs (e.g., Canadarm). In parallel manipulators (PMs), however, redundancy is still in its infancy. Some recent works have used redundancy to tackle a few common issues of PMs (e.g., small and/or highly singular workspaces) and to develop new or improved manipulator architectures. The research proposed here will study actuation redundancy from theoretical and practical perspectives.******In terms of actuation redundancy, the focus will be on Cable Driven Parallel Manipulators (CDPMs) which have potentially large workspaces. Although it is possible to design CDPMs with very large workspaces (e.g., the SkyCam), the resulting CDPMs have a very large footprints as well. This is mostly due to the fact that cables can only pull and always need to be kept in tension. Here, it is proposed to enhance CDPMs with actuated coiled or telescopic struts that will essentially create manipulators with hybrid actuation. Since the new actuated members would permit both pushing and pulling, the region in space in which the manipulator can perform tasks can be extended quite significantly.******Efficiently determining the region in which a manipulator can apply or sustain a certain minimum force/moment couple is essential to determining the best manipulator for a specific task. New methods and efficient computational tools are required to perform this task fast enough to allow optimal design of manipulators. With these methods and tools, a robot designer would be able to determine the number, placement and characteristics of all the actuators (whether they are cables or coiled/telescopic struts) to perform the desired task.******An important part of the proposed work is the study and design of the actuators using either tape springs or novel elements such as slit tubes or bistable composite tubes. These light members can be deployed from a spool yet they can sustain axial forces in both directions. That is, they will allow forces to be applied both in tension and compression while having relatively long strokes. Although variants of this technology have existed for over two decades, they have been used on low speed applications such as deployable space structures. Here, the intention is to use the technology in relatively high speed applications. These actuators will greatly enhance the scope and allow new practical application of CDPMs.******Overall, this work will give robot designers better design tools for PMs and a larger selection of kinematic architectures. A very significant by-product of the work will be the development and design of extensible rods for high speed applications.

多年来，串行机械手中不同类型的冗余已经达到了良好的成熟水平。最值得注意的是，运动冗余（即添加比任务严格要求更多的关节和连杆）以获得更好的运动性能或避障一直是许多工作和成功的机械臂设计（例如，Canadarm）的焦点。然而，在并联机械手 (PM) 中，冗余仍处于起步阶段。最近的一些工作使用冗余来解决 PM 的一些常见问题（例如，小型和/或高度单一的工作空间）并开发新的或改进的操纵器架构。这里提出的研究将从理论和实践的角度研究驱动冗余。******在驱动冗余方面，重点将放在具有潜在大工作空间的电缆驱动并联机械手（CDPM）上。尽管可以设计具有非常大工作空间（例如 SkyCam）的 CDPM，但最终的 CDPM 也具有非常大的占地面积。这主要是因为电缆只能拉动并且始终需要保持拉力。在这里，建议使用驱动的螺旋或伸缩支柱来增强 CDPM，这基本上将创建具有混合驱动的机械手。由于新的驱动构件允许推和拉，因此机械手可以执行任务的空间区域可以显着扩展。******有效地确定机械手可以应用或维持某个最小值的区域力/力矩耦合对于确定特定任务的最佳操纵器至关重要。需要新的方法和高效的计算工具来足够快地执行这项任务，以实现机械臂的优化设计。通过这些方法和工具，机器人设计人员将能够确定所有执行器（无论是电缆还是卷绕/伸缩支柱）的数量、位置和特性，以执行所需的任务。******重要的一部分拟议的工作是研究和设计使用带弹簧或新颖元件（例如狭缝管或双稳态复合管）的执行器。这些轻型构件可以从线轴展开，但它们可以承受两个方向的轴向力。也就是说，它们将允许在拉伸和压缩方面施加力，同时具有相对较长的冲程。尽管该技术的变体已经存在了二十多年，但它们已用于低速应用，例如可部署空间结构。这里的目的是在相对高速的应用中使用该技术。这些执行器将极大地扩大 CDPM 的范围并允许新的实际应用。******总的来说，这项工作将为机器人设计人员提供更好的 PM 设计工具和更多的运动学架构选择。这项工作的一个非常重要的副产品将是用于高速应用的可伸缩杆的开发和设计。