Rapidly Deployable Cable-Driven Parallel Robots

可快速部署的电缆驱动并联机器人

• 批准号: RGPIN-2021-03294
• 负责人: Cardou, Philippe
• 金额: $ 1.97万
• 依托单位: Université Laval
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2021
• 资助国家: 加拿大
• 起止时间: 2021-01-01 至 2022-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=742480
• 关键词: Rapidly; Deployable; Cable; Driven; Parallel

Cable--driven parallel robots (CDPRs) consist of an end effector suspended by a number of cables. Each cable is wound onto a servo-actuated spool, which is rigidly attached to a fixed frame. The end-effector displacements are controlled by simultaneously winding or unwinding the cables on their respective spools. Our interest in CDPRs stems from four advantages they hold over classical rigid-link robots: large workspaces; low cost; high speeds and accelerations; portability and reconfigurability. In our opinion, this latter advantage, the portability and reconfigurability of CDPRs, has been relatively neglected in previous research. We believe that this could be significantly improved by solving three problems: (1-2) making the CDPR calibration fully autonomous (3) designing new spools that can be mounted on towers rather than buttressed structures and (4-5) quickly tracing and certifying their workspace. The hardware will not have to be rebuilt from scratch for each project, because a dynamically reconfigurable CDPR is available at the Laboratoire de robotique. In projects (1-2), we will devise a mathematical method that allows to identify the CDPR mechanical model without the prior estimate of its parameters required by current calibration methods. Measuring the dimensions of a newly deployed cable robot is time consuming and constitutes an important limitation to its portability. The proposed method will be demonstrated through the dynamically reconfigurable CDPR already available and by designing a new highly portable lightweight CDPR. Project (3) was established from the observation that current CDPRs resemble more gantry cranes than tower cranes. To minimise the CDPR structure, we want to attach its spools on towers free of large buttresses, stabilisers or tethers. We will achieve this objective by cancelling the moment induced at the base of the tower by the cable tension applied at its top. A moving counterweight driven by the winch and cable direction will be used to cancel the moment. We will demonstrate this concept on a two--degree--of-freedom cable--suspended parallel robot in the vertical plane. In projects (4-5), we wish to develop faster methods for tracing and certifying the wrench-feasible workspace of CDPRs. The fastest available methods for tracing the workspace are based on line search, following rays emanating from a point until they intersect the workspace surface. We will propose a method where a path is followed along the workspace surface by using a predictor-corrector scheme. This method should be faster, as every point predicted along the path will be close to the true workspace surface, ensuring a fast correction step. As this type of workspace tracing method is not guaranteed to find the whole workspace, we will also develop a certification method. This method will consist in a branch-and-prune algorithm in which the lower bounds are computed through convex relaxations.

电缆驱动并联机器人（CDPR）由一个由多根电缆悬挂的末端执行器组成。每根电缆都缠绕在伺服驱动的线轴上，该线轴牢固地连接到固定框架上。通过同时缠绕或松开各自线轴上的电缆来控制末端执行器的位移。我们对 CDPR 的兴趣源于它们相对于传统刚性连杆机器人的四个优势：大工作空间；低成本;高速度和加速度；可移植性和可重构性。我们认为，后一个优点，即 CDPR 的可移植性和可重构性，在以前的研究中相对被忽视了。我们相信，通过解决三个问题可以显着改善这一点：（1-2）使 CDPR 校准完全自主（3）设计可以安装在塔上而不是支撑结构上的新线轴，以及（4-5）快速跟踪和认证其工作空间。不必为每个项目从头开始重建硬件，因为机器人实验室提供了动态可重新配置的 CDPR。在项目（1-2）中，我们将设计一种数学方法，允许识别 CDPR 机械模型，而无需事先估计当前校准方法所需的参数。测量新部署的电缆机器人的尺寸非常耗时，并且对其便携性构成了重要限制。所提出的方法将通过现有的动态可重构 CDPR 以及设计新型高度便携的轻量级 CDPR 进行演示。项目（3）是根据目前的 CDPR 更像龙门起重机而不是塔式起重机的观察而建立的。为了最大限度地减少 CDPR 结构，我们希望将其线轴固定在没有大型支撑、稳定器或系绳的塔上。我们将通过消除塔顶部施加的缆索张力在塔底部引起的力矩来实现这一目标。由绞车和缆索方向驱动的移动配重将用于消除力矩。我们将在垂直平面上的二自由度缆绳悬挂并联机器人上演示这一概念。在项目 (4-5) 中，我们希望开发更快的方法来跟踪和验证 CDPR 的扳手可行工作空间。追踪工作空间的最快可用方法是基于线搜索，跟踪从一点发出的光线，直到它们与工作空间表面相交。我们将提出一种方法，其中使用预测器-校正器方案沿着工作空间表面跟踪路径。该方法应该更快，因为沿路径预测的每个点都将接近真实的工作空间表面，从而确保快速校正步骤。由于此类工作区追踪方法不能保证找到整个工作区，因此我们还将开发一种认证方法。该方法将包含分支修剪算法，其中通过凸松弛计算下限。