Path planning of cable-driven parallel robots (CDPRs) is a challenging task due to cables which may cause various collisions. In this paper, three steps are suggested to perform path finding of CDPRs in cluttered environments. First, a way to visualize the cable collision of CDPRs is suggested to consider actual workspace of CDPRs. Second, a path finding algorithm based on rapidly exploring random trees (RRT) is presented to find a path free of various collisions of CDPRs including cable collisions and wrench feasible workspace. While conventional RRT algorithms are mainly focused on mazy environments, the modified RRT algorithm proposed here directly connects a sampled node and the tree to find a path faster in a non-mazy, but cluttered environment. Goal-biased sampling algorithm is also modified and employed to decrease computational cost. To deal with complicated collision detection of cables in the RRT, Gilbert–Johnson–Keerthi algorithm was employed. Finally, post-processing algorithm for any waypoint-based path is suggested to get a shorter and less winding path. A numerical study was carried out to suggest choosing proper meta parameters for the post-processing algorithm. The suggested algorithms were evaluated with 1000 times of simulations, and they were equally carried out for RRT* to compare. According to the results, the suggested algorithm found a shorter path with less computation time compared to RRT* and the post-processing algorithms made the already found path shorter.

中文翻译：

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杂乱环境中的电缆驱动并行机器人的无冲突路径规划

电缆驱动的并行机器人（CDPR）的路径规划是一项艰巨的任务，因为电缆可能会引起各种碰撞。在本文中，建议在混乱环境中执行CDPR路径查找的三个步骤。首先，建议使用可视化CDPR电缆碰撞的方法来考虑CDPR的实际工作空间。其次，提出了一种基于快速探索随机树（RRT）的路径查找算法，以找到无CDPR各种碰撞（包括电缆碰撞和扳手可行工作空间）的路径。尽管常规的RRT算法主要集中在朦胧的环境中，但是这里提出的改进的RRT算法直接将采样的节点和树连接起来，从而在非混乱但混乱的环境中更快地找到路径。目标偏向采样算法也被修改并用于降低计算成本。为了处理RRT中电缆的复杂碰撞检测，采用了Gilbert-Johnson-Keerthi算法。最后，建议对任何基于航路点的路径进行后处理算法，以获取更短且更少的弯曲路径。进行了数值研究，建议为后处理算法选择合适的元参数。对建议的算法进行了1000次仿真评估，并对RRT *进行了均等的比较。根据结果​​，与RRT *相比，所建议的算法找到的路径更短，计算时间更少，而后处理算法使已经找到的路径更短。建议对任何基于航点的路径进行后处理算法，以获取更短且更少的弯曲路径。进行了数值研究，建议为后处理算法选择合适的元参数。对建议的算法进行了1000次仿真评估，并对RRT *进行了均等的比较。根据结果​​，与RRT *相比，所建议的算法找到的路径更短，计算时间更少，而后处理算法使已经找到的路径更短。建议对任何基于航点的路径进行后处理算法，以获取更短且更少的弯曲路径。进行了数值研究，建议为后处理算法选择合适的元参数。对建议的算法进行了1000次仿真评估，并对RRT *进行了均等的比较。根据结果​​，与RRT *相比，所建议的算法找到的路径更短，计算时间更少，而后处理算法使已经找到的路径更短。