Abstract
Aerial unperching of multirotors has received little attention as opposed to perching that has been investigated to elongate operation time. This study presents a new aerial robot capable of both perching and unperching autonomously on/from a ferromagnetic surface during flight, and a switching controller to avoid rotor saturation and mitigate overshoot during transition between free-flight and perching. To enable stable perching and unperching maneuvers on/from a vertical surface, a lightweight ($\approx$ $1$ \si{kg}), fully actuated tiltrotor that can hover at $90^\circ$ pitch angle is first developed. We design a perching/unperching module composed of a single servomotor and a magnet, which is then mounted on the tiltrotor. A switching controller including exclusive control modes for transitions between free-flight and perching is proposed. Lastly, we propose a simple yet effective strategy to ensure robust perching in the presence of measurement and control errors and avoid collisions with the perching site immediately after unperching. We validate the proposed framework in experiments where the tiltrotor successfully performs perching and unperching on/from a vertical surface during flight. We further show effectiveness of the proposed transition mode in the switching controller by ablation studies where large overshoot and even collision with a perching site occur. To the best of the authors' knowledge, this work presents the first autonomous aerial unperching framework using a fully actuated tiltrotor.
Abstract (translated)
飞行中多旋翼的 aerial 静止相对于静止在磁性表面上的研究关注较少。本研究提出了一种能够自主飞行时静止和起飞时静止在磁性表面的全新多旋翼机器人以及一种用于避免转子饱和和减轻起飞和静止之间过渡时的过冲的控制器。为了实现从垂直表面稳定进行静止和起飞，我们首先开发了重量轻（约1 kg）的全电动倾斜旋翼，能够在$90^\circ$的俯仰角下悬停。我们设计了一个由一个伺服电机和一个磁铁组成的静止/起飞模块，并将其安装在倾斜旋翼上。我们提出了一个包括自由飞行和起飞之间过渡 exclusive 控制模式的切换控制器。最后，我们提出了一种简单而有效的策略，以确保在测量和控制误差存在的情况下和在起飞后立即避开静止位置的碰撞。我们在飞行实验中验证了所提出的框架。我们进一步通过断续试验研究了所提出的转换模式的有效性，在试验中，倾斜旋翼在飞行中成功进行了静止和起飞。通过断续试验研究，我们证明了所提出的转换模式的有效性。据作者知识，本研究是第一个使用全电动倾斜旋翼实现自主飞行静止的框架。
URL
https://arxiv.org/abs/2404.11310
