Autonomous visual interception of agile aerial targets is challenging due to unpredictable target motion, limited sensing, and the strong coupling between target visibility and interceptor maneuverability. Most existing strapdown-camera interception methods preserve visibility using conic line-of-sight (LOS) constraints that keep the target near the image center. While safe, such symmetric constraints unnecessarily restrict maneuverability and can significantly reduce the usable thrust for pursuit. Motivated by the observation that aggressive FPV pilots do not maintain equal visibility margins in all image directions, this paper proposes a Planar-Sector Line-of-Sight (PS-LOS) guidance framework for autonomous interception using a lifting-wing quadcopter equipped with only a strapdown monocular camera. PS-LOS tightly constrains lateral image error while relaxing longitudinal image error within a safe field-of-view margin, preserving visibility while releasing maneuverability for acceleration-intensive pursuit. Under the lifting-wing quadcopter model, PS-LOS provides nearly 50% more available thrust near the LOS direction than conventional conic LOS constraints. To realize LOS-only interception without direct depth measurements, a delay-compensated state-estimation framework and a nonlinear guidance-and-control architecture are developed for lifting-wing quadcopters. Extensive outdoor flight experiments demonstrate autonomous interception of agile targets exhibiting large-amplitude, high-frequency, and unpredictable motion under real wind disturbances. The proposed system achieves successful interceptions at ranges up to 138 m while maintaining continuous visual tracking throughout the engagement. The results validate PS-LOS as a visibility-preserving, maneuverability-aware guidance framework for long-range visual interception of agile aerial targets.

翻译：自主视觉拦截敏捷空中目标因其不可预测的机动、有限感知能力以及目标可见性与拦截器机动性之间的强耦合性而具有挑战性。现有捷联相机拦截方法通常采用圆锥形视距约束将目标保持在图像中心附近以维持可见性。这种对称约束尽管安全，但会不必要地限制机动能力，并显著减少可用推力的追击效能。受特技飞行FPV飞行员在图像各方向维持不等可见性裕度这一观察的启发，本文提出一种基于平面扇形视距的自主拦截制导框架，适用于仅配备捷联单目相机的升力翼四旋翼。平面扇形视距方法在严格约束横向图像误差的同时，在安全视场角裕度内放松纵向图像误差约束，从而在保持可见性的同时释放用于加速追击的机动能力。在升力翼四旋翼模型下，与传统圆锥形视距约束相比，该框架在视距方向附近提供近50%的额外可用推力。为实现在无直接深度测量条件下的纯视距拦截，本文开发了含延时补偿的状态估计框架及面向升力翼四旋翼的非线性制导控制架构。大量室外飞行实验表明，该系统能在真实风扰环境下成功拦截具有大幅值、高频、不可预测运动的机动目标。该系统可实现最远138米的有效拦截，并在作战全程保持连续视觉跟踪。实验结果验证了平面扇形视距作为保持可见性与感知机动性的长距离视觉拦截制导框架的有效性。