This letter presents a novel and retractable ring-shaped quadrotor called Ring-Rotor that can adjust the vehicle's length and width simultaneously. Unlike other morphing quadrotors with high platform complexity and poor controllability, Ring-Rotor uses only one servo motor for morphing but reduces the largest dimension of the vehicle by approximately 31.4\%. It can guarantee passibility while flying through small spaces in its compact form and energy saving in its standard form. Meanwhile, the vehicle breaks the cross configuration of general quadrotors with four arms connected to the central body and innovates a ring-shaped mechanical structure with spare central space. Based on this, an ingenious whole-body aerial grasping and transportation scheme is designed to carry various shapes of objects without the external manipulator mechanism. Moreover, we exploit a nonlinear model predictive control (NMPC) strategy that uses a time-variant physical parameter model to adapt to the quadrotor morphology. Above mentioned applications are performed in real-world experiments to demonstrate the system's high versatility.
翻译:本文提出了一种新型可收回的环形四旋翼Ring-Rotor,它可同时调整车辆的长度和宽度。与其他复杂度高且控制性能差的变形四旋翼不同,Ring-Rotor仅使用一个伺服电机进行变形,但可减少车辆最大尺寸约31.4%。它能够保证在紧凑形态下穿过狭小的空间,同时在标准形态下节能。与此同时,该车辆打破了一般四旋翼的十字形配置,创新的环形机械结构具有一定的中心空间。基于此,设计了一个巧妙的全机身空中抓取和运输方案,可携带各种形状的物体而无需外部操纵器。此外,我们利用非线性模型预测控制(NMPC)策略,使用时变物理参数模型来适应四旋翼的形态。上述应用在实际世界实验中得到了展示,表明了系统的高度多功能性。