Autonomous Micro Aerial Vehicles are deployed for a variety tasks including surveillance and monitoring. Perching and staring allow the vehicle to monitor targets without flying, saving battery power and increasing the overall mission time without the need to frequently replace batteries. This paper addresses the Active Visual Perching (AVP) control problem to autonomously perch on inclined surfaces up to $90^\circ$. Our approach generates dynamically feasible trajectories to navigate and perch on a desired target location, while taking into account actuator and Field of View (FoV) constraints. By replanning in mid-flight, we take advantage of more accurate target localization increasing the perching maneuver's robustness to target localization or control errors. We leverage the Karush-Kuhn-Tucker (KKT) conditions to identify the compatibility between planning objectives and the visual sensing constraint during the planned maneuver. Furthermore, we experimentally identify the corresponding boundary conditions that maximizes the spatio-temporal target visibility during the perching maneuver. The proposed approach works on-board in real-time with significant computational constraints relying exclusively on cameras and an Inertial Measurement Unit (IMU). Experimental results validate the proposed approach and shows the higher success rate as well as increased target interception precision and accuracy with respect to a one-shot planning approach, while still retaining aggressive capabilities with flight envelopes that include large excursions from the hover position on inclined surfaces up to 90$^\circ$, angular speeds up to 750~deg/s, and accelerations up to 10~m/s$^2$.

翻译：自主微型飞行器被部署用于监控与侦察等多样化任务。悬停与栖落功能使飞行器无需持续飞行即可完成目标监测，从而节省电池电量并延长任务总时长，减少频繁更换电池的需求。本文针对主动视觉栖落控制问题展开研究，旨在实现飞行器在倾斜角高达90°的斜面上自主栖落。所提方法通过生成动态可行的轨迹，引导飞行器导航至目标位置并完成栖落，同时考虑执行器约束与视场约束。通过空中重规划机制，利用更精确的目标定位信息提升栖落机动对定位误差与控制误差的鲁棒性。基于Karush-Kuhn-Tucker条件，本文识别出规划目标与机动过程中的视觉感知约束之间的兼容性，并通过实验确定最大化栖落机动期间时空目标可见度的边界条件。该方法完全依赖摄像头与惯性测量单元实现在线实时运行，显著克服了计算资源限制。实验验证了所提方法的有效性，与单次规划方法相比，该方法在保持激进飞行能力的同时，展现出更高的成功率、目标拦截精度与准确度，其飞行包线包含从悬停位置至90°斜面的大幅偏移、750°/s的角速度及10m/s²的加速度。