Continuously bending reconfigurable robot manipulators for flexible handling and assembly in confined and remote environments

大多数串联机器人采用传统的多关节、多连杆的刚性连杆设计。然而，对于这些机器人在较小空间中执行的多个单独任务，较低的自由度（DOF）就足够了。这包括制造电子产品和海上作业等活动，在这些活动中，在狭小的空间和偏远的地方工作至关重要。这种情况的其他例子还有深海、危险材料处理和太空机器人。虽然对于任务来说是足够的，但低自由度限制了工作空间，因此限制了系统的灵活性，阻碍了机器人适应各种任务的能力。对于需要复杂定位的偏远地区的工作，具有较高DOF的传统机械臂似乎更合适，因为较高的DOF允许机械臂适应给定的场景，完成提供的更大范围的复杂任务。然而，较高的自由度会导致机器人更大、更重，有时甚至比特定活动所需的更复杂。当需要满足机器人要求时，这可能会造成特定的限制，例如空间机器人的重量限制。因此，这个问题的理想解决方案是一个更简单，低自由度的机器人，保持系统的灵活性。软机械臂通常使用单个连续弯曲连杆来实现，相对于僵硬的离散机械臂有许多改进，例如随着系统灵活性的增加而减小尺寸和重量要求；然而，这些机器人系统一直在努力达到完全刚性设计的保持强度和精度。最近的研究探索了在外科手术用软连续体机器人中使用变刚度连杆，通过改变机器人的刚度b[4][5]，它包含了这两个系统的各个方面。这一发展使机器人克服了软机器人的强度限制，当机器人被“激活”时，它提供了一个刚性平台。然而，目前还没有一种减少自由度的机器人能够适应可变但可控工作空间的多任务；这些机器人是过程自动化和在受限和远程环境中增强人类操作员能力的需要。本研究旨在结合、改进和扩展软机器人技术的现有研究，用于可重构的系列臂，生产自由度减少的机器人，可以使用可变刚度链接调整其拓扑结构，从而能够执行一系列任务，重点是搬运和取放组装操作。这些系统的理想实现将是协作机器人，用于需要具有高自由度性能的小尺寸/重量机器人，即深海和太空机器人。这些新型机械手具有更大的灵活性，可以适应不同的工作空间，同时保持较低自由度机器人系统的优点，如重量、尺寸和控制复杂性。所提出的机器人将使用外部延展性链接的系列链来制造：一个可变刚度，灵活的，连续弯曲的链接，当处于非刚性状态时，可以用手重新定位，同时在激活时保持其位置。这些可延展的环节将通过旋转关节连接起来，从而能够执行传统机械臂所能执行的操作。

The majority of serial robots use traditional rigid-link designs with multiple joints and links [1]. However, for multiple individual tasks that are performed by these robots in reduced spaces, a lower number of degrees of freedom (DOF) is sufficient [2]. This includes activities such as manufacturing electronics and offshore operations, where working inside reduced spaces and in remote locations is vital. Other examples of such situations are deep sea, hazardous material handling, and space robotics. Whilst sufficient for the task, a low DOF limits the workspace, and therefore the flexibility of the system, hindering the ability for the robot to adapt to various tasks. For work within remote areas that requires complex positioning, a traditional robot arm with higher DOF seems more appropriate for instance, as a higher DOF allows the robot arm to adapt to given scenarios, accomplishing a larger range of complex tasks provided. Nevertheless, a higher number of DOF causes the robot to be larger, heavier, and sometimes more complex than necessary for particular activities. This can cause specific limitations when robotic requirements are needed to be met, for example weight limitations with space robotics. The ideal solution to this problem therefore is a simpler, low DOF robot that maintains the flexibility of the system.Soft robot arms, implemented usually using a single continuously bending link, promise a number of improvements over stiff, discrete manipulators such as reduced size and weight requirements with an increase in system flexibility; however, these robotic systems have been struggling to achieve the holding strength and precision of fully rigid designs [3]. Recent research has explored the use of variable stiffness links in soft, continuum robots for surgery, which contains aspects of both systems by varying the rigidity of the robot [4][5]. This development allows the robot to overcome the strength limitation of soft robotics, by providing a rigid platform when the robot is 'activated'. However, at present, no robots with a reduced number of DOF that can be adaptable to multiple tasks with variable but controllable workspace exist; these robots are a need for the automation of processes and the augmentation of human operator capabilities in confined and remote environments.This research aims to combine, improve, and extend existing research in soft robotics for use in reconfigurable serial arms, producing robots with a reduced number of DOF that can adjust their topology using variable stiffness links, thus being able to perform a range of tasks with a focus on handling and pickand-place assembly operations. Ideal implementations of these systems would be as collaborative robotics in operations that require a reduced size/weight robot with a high DOF performance, namely deep sea and space robotics. These novel manipulators have the possibility of greater flexibility by adapting to different workspaces while keeping the benefits of a lower DOF robotic system, such as weight, size, and control complexity. The proposed robots will be fabricated using serial chains of extrinsic malleable links: A variable stiffness, flexible, continuously bending link which can be repositioned by hand when in a non-rigid state, while holding its position when activated. These malleable links will be connected by revolute joints to be able to perform the operations that can be carried out with traditional robotic arms.