Spinoff is NASA's annual publication featuring successfully commercialized NASA technology. This commercialization has contributed to the development of products and services in the fields of health and medicine, consumer goods, transportation, public safety, computer technology, and environmental resources.

Self-piloted drone traffic may be just over the horizon but for now, vehicles cannot legally fly beyond the operator's line of sight — at least not without special permission. While the Federal Aviation Administration (FAA) works to craft drone regulations and engineers work to build the features that would meet those rules, some of this new technology is opening up applications that don't involve flying across town.

For example, using unmanned aerial systems (UAS) to inspect bridges, buildings, and other infrastructures or survey disaster sites doesn't necessarily require FAA compliance. An impediment to this sort of application, though, has been reliance on the GPS signals that such structures can obstruct. Without GPS, drone navigation drifts, making it difficult to register data from onboard sensors and eventually causing instability. With NASA's help, Pittsburgh-based Near Earth Autonomy is breaking the dependency drones have on GPS.

NASA has taken a leading role in pioneering and fostering advances necessary for safe autonomous flight, establishing in 2015 its UAS Traffic Management (UTM) project centered at Ames Research Center. That year, Ames granted Phase I and II Small Business Innovation Research (SBIR) contracts to Near Earth Autonomy to build the technology for safe, self-piloted takeoff and landing without the use of GPS or maps.

Near Earth Autonomy's simultaneous mapping and localization system builds a map of a drone's surroundings — such as this network of tunnels — while it tracks the craft's movement through that environment.

As the UTM project brings on commercial partners, it directs them to focus efforts on the areas of need it has identified for future autonomous air traffic. One of the challenges of drone traffic management is the ability to operate without GPS. That's partly because one of the FAA's requirements will be the ability to navigate in the event of a GPS outage and because GPS signals can often be degraded at low altitudes in urban areas — exactly where the highest precision is needed.

The problem is that most automated navigation systems start by determining their location with GPS. Devising a good alternative is challenging, not least because a small drone has limited power and can't carry much weight, so whatever sensors are put on a drone must have very low size, weight, and power. Near Earth Autonomy's SBIR work focused on safely navigating the most difficult parts of a flight — the first and last 50 feet. In practice, this meant flying entire short missions with no GPS.

The company managed GPS-free navigation with a technique known as simultaneous localization and mapping. As it flies, the drone has to build a map of its surroundings while tracking its own movement through that environment. An onboard LiDAR scanner senses physical surroundings and their distances by measuring how long laser pulses sent in all directions take to bounce back to a sensor. Meanwhile, inertial sensors record the craft's movements, assisted by a camera for visual tracking. The Near Earth Autonomy team had to create their own algorithms to continually process all of that data and successively stitch together a map and use it to navigate. And the company was able to do it using small, state-of-the-art commercial components, minimizing the weight and cost of the payload.

NASA will have an interest in the technology not just for drone traffic management but also for missions over the poles, where GPS signals don't reach. In the long term, the capability to navigate without GPS could help make FAA drone regulations a reality. And it could one day enable capabilities such as autonomous urban transport.

Near Earth Autonomy has received the most interest from entities that want drones to be able to navigate near or inside large, potentially GPS-disrupting structures for disaster site surveillance and for inspecting buildings, tunnels, bridges, tanks, and towers. The company has sold a few prototypes and is working with commercial and government entities to adapt the technology to specific applications and bring costs down.

Visit here .


Tech Briefs Magazine

This article first appeared in the October, 2020 issue of Tech Briefs Magazine.

Read more articles from this issue here.

Read more articles from the archives here.