Transporting objects using aerial robots has been widely studied in the literature. Still, those approaches always assume that the connection between the quadrotor and the load is made in a previous stage. However, that previous stage usually requires human intervention, and autonomous procedures to locate and attach the object are not considered. Additionally, most of the approaches assume cables as rigid links, but manipulating cables requires considering the state when the cables are hanging. In this work, we design and control a \emph{catenary robot}. Our robot is able to transport hook-shaped objects in the environment. The robotic system is composed of two quadrotors attached to the two ends of a cable. By defining the catenary curve with five degrees of freedom, position in 3-D, orientation in the z-axis, and span, we can drive the two quadrotors to track a given trajectory. We validate our approach with simulations and real robots. We present four different scenarios of experiments. Our numerical solution is computationally fast and can be executed in real-time.

中文翻译：

---

悬链机器人：两个四旋翼推进器的电缆的设计和控制

在文献中已经广泛地研究了使用空中机器人来运输物体。尽管如此，这些方法始终假定四旋翼和负载之间的连接是在前一级进行的。但是，该前一阶段通常需要人工干预，因此不考虑用于定位和附加对象的自主程序。另外，大多数方法都将电缆视为刚性连接，但是操纵电缆需要考虑电缆悬挂时的状态。在这项工作中，我们设计和控制\ emph {catenary robot}。我们的机器人能够在环境中运输钩状物体。机器人系统由连接到电缆两端的两个四旋翼转子组成。通过定义具有5个自由度的悬链曲线，3-D位置，z轴方向和跨度，我们可以驱动两个四旋翼飞机来跟踪给定的轨迹。我们通过仿真和真实的机器人来验证我们的方法。我们介绍了四种不同的实验场景。我们的数值解决方案计算速度快，并且可以实时执行。