Visual breadcrumbs for emergency return of unmanned aerial vehicles

无人机（UAV）技术在过去十年中发展迅速，使自动化，按需遥感和交付成为近期现实，应用范围从精准农业到应急响应操作以及侦察和监视。目前尚待开发的一个关键组成部分是实现安全超视距飞行的解决方案，并防止车辆在通信和/或GPS信号丢失等故障情况下失控。该提案的主要目标是开发一种基于视觉的导航解决方案，使无人机在失去通信和定位手段（即GPS）时能够安全返回家园。基于视觉的导航技术将使无人机能够确定其相对于飞行期间或飞行前获得的航空地图的位置。多伦多大学（UofT）在过去十年中一直致力于开发地面车辆的视觉路线跟踪技术，并在自主飞行控制算法设计方面积累了丰富的经验。该项目将需要主要的扩展，包括将地面视觉导航框架适应空中应用，以及开发基于视觉的飞行控制器，以保证强大的定位和安全着陆。该项目将与PrecisionHawk（位于加拿大的一家新兴的世界级固定翼无人机供应商）以及加拿大国防研究与发展公司（DRDC）合作执行，后者使用基于旋翼的无人机进行各种国防应用（例如，复杂城市地区的监视）。这种基于视觉的导航技术的飞跃将使UofT在无人机安全、长期自主领域取得核心科学进步，并将使PrecisionHawk和DRDC将这些进步纳入其未来的产品和解决方案中，从而显着提高无人机的安全性及其应用范围。此外，本文提出的安全解决方案将有助于加快无人机在超边线应用中商业用途的监管框架的发展。

Unmanned Aerial Vehicle (UAV) technology has advanced at a rapid pace in the last decade, making automated, on-demand remote sensing and delivery a near-term reality with applications ranging from precision agriculture to emergency response operations and reconnaissance & surveillance. A key building block that is yet to be developed is a solution that enables safe beyond-line-of-sight flight, and prevents uncontrolled vehicle behavior in the event of failures such as communication and/or GPS signal loss. The main goal of this proposal is to develop a vision-based navigation solution that enables UAVs to safely return home when they lose their means of communication and localization (i.e., GPS). Vision-based navigation techniques will enable the UAV to determine its location relative to an aerial map recorded during flight or obtained prior to flight. The University of Toronto (UofT) has been developing visual route-following techniques for ground vehicles for the past decade and also gained extensive experience in control algorithm design for autonomous flight. This project will require major extensions including the adaptation of the ground-based visual navigation framework to aerial applications and the development of a vision-based flight controller that guarantees robust localization and safe landing. The project will be carried out in partnership with PrecisionHawk, an emerging world-class provider of fixed-wing UAVs located in Canada, as well as Defence Research & Development Canada (DRDC), which uses rotor-based UAVs for a variety of defence applications (e.g., surveillance of complex urban areas). This leap forwards in vision-based navigation technology will allow UofT to make core scientific advances in the area of safe, long-term autonomy of UAVs and will allow PrecisionHawk and DRDC to incorporate these advances in their future products and solutions, thereby significantly increasing the safety of UAVs and their range of applications. Moreover, safety solutions as proposed here will help to accelerate the development of a regulatory framework for the commercial use of UAVs in beyond-line-of-side applications.