Ground robot, drone maker takes new approach to aerial precision

By Luke Geiver | December 03, 2015

A Silicon Valley unmanned aircraft systems (UAS) startup is applying the lessons learned from its work on the film Gravity to guide its efforts at building a ground-based robot and drone combo system. The system is capable of precise, automated navigation in close proximity to cell towers and other vertical structures to capture detailed imagery that is not possible with GPS, according to the company.

Prior to forming Prenav, founders Nathan Schuett and Asa Hammond worked for Google and other firms performing freelance robotic and software work. For the film Gravity, Hammond designed a system—complete with software—that involved a 10,000 pound robotic arm fitted with high-end cameras. The system was used to create the illusion that actors in the movie were floating in space through precise maneuvers. “We are building a very similar system for drones,” said Schuett, Prenav’s CEO.

For UAS operations, the Prenav system attempts to use preflight information to create a precise flight plan that can assure a sUAV can capture imagery from particular aerial locations. A robot on the ground perched atop a tripod similar to those used in surveying scans the environment prior to flight. “If we are doing a cell phone tower or wind turbine we scan the tower first from the ground and then we know the height and any obstacles we need to avoid,” Schuett said. “We can design a flight path that will capture everything we are interested in and preview it first on a tablet.”

After the preflight information is acquired and the flight path created, the ground system communicates with the inflight UAV via wifi and 100 Hz radio link. “They are synchronized and communicating constantly before and during the flight,” Schuett said. The system allows for greater precision in image or information capture. Because the unit is not relying on GPS during flight, it can also sustain operations in high wind or difficult weather conditions, according to Schuett.

“If you are trying to be underneath a bridge or a meter away from a wind turbine blade, you can’t trust GPS to do that,” he said.

To showcase the Prenav’s precision flight capabilities, the team tapped into their filmmaking experience to create an award-winning short film. In the film, the team mounted LED lights on its commercial grade UAV platform. Using a preflight plan, the platform was flown to spell out the phrase, “hello world.” At predetermined intervals and places, the operating software turned the LED lights on. After the flight, the team combined its footage of the system in action to show the results of the flight plan. The flight spelled out the phrase, ultimately highlighting how precise the system can fly. “It is very similar, whether you are blinking an LED or taking a video, the ability to move the drone to any point in space is important,” he said. “Being able to do it over and over again is useful for aerial filmmaking and for infrastructure work.”

In late October, Prenav received its first U.S. Federal Aviation Administration section 333 exemption to perform commercial operations. The process took roughly six months from start to finish, but today the team believes the 333 has helped it when talking to current or future customers. “I’m really looking forward to the NPRM becoming rule next summer and the process of work becoming more accessible,” he said.

While Prenav considers itself a commercial product manufacturer and UAS service provider, investors in the company and future clients will have to wait until 2016 to have access to its unique system. The company plans to officially launch its product next year. Until then, the team is planning more videos to showcase its unique concept.