For drones and other autonomous vehicles to carry out lengthy, meaningful assignments such as ongoing aerial surveillance or a day of delivering packages, they will need a reliable way to recharge their batteries with little or no human intervention.
Seattle-based startup WiBotic, a spinout from the University of Washington, is developing a suite of wireless charging technology and battery management software that would enable a drone to land on a base station for a quick fill-up, or a slow, battery-friendly overnight recharge.
The company, which recently raised a $2.5 million seed funding round from Tsing Capital and other investors, is one of several startups and more established companies trying to crack wireless power, using various technologies, for a wide range of applications. Just in the Seattle area, there’s Ossia, which is developing its Cota technology, designed to charge multiple devices in a room, and LaserMotive, which aims to send beams of power to drones in flight or vehicles in space.
Wireless charging has been around in concept for a long time. No less a pioneer than Nikola Tesla demonstrated it at the dawn of the 20th century. You probably have at least one application of wireless inductive charging in your home already. When’s the last time you plugged in your electric toothbrush?
Market forecasts for wireless charging are bullish. Global Market Insights Inc., for one, predicts global revenue of $25 billion by 2023, a nearly tenfold increase from $2.62 billion in 2015. The technology appears poised for a major coming out with the release of the Apple iPhone 8, rumored to be equipped for wireless inductive charging—a rumor fueled earlier this year by Apple’s joining one of two large wireless power industry groups, the Wireless Power Consortium, with its Qi standard. Samsung, meanwhile, announced in April that inductive wireless charging would be a feature of its forthcoming Galaxy S8, using the AirFuel Inductive charging technology standard supported by the other big industry group, the AirFuel Alliance.
While the electronics industry sorts out these standards—which will save people like me from hassling with lint-clogged power ports and nightstand cord knots—WiBotic is focused on industries where human intervention is not just an inconvenience, but a real potential hindrance to the cost savings that autonomous systems promise in the first place.
Today, a commercial drone or robot operator working at a movie set or construction site might bring along up to 100 batteries for a day’s flying, depending on the size of their fleet, says WiBotic co-founder and CEO Ben Waters (pictured above). The operator will spend a good portion of his or her day swapping out batteries and keeping track of which ones have been charged.
A drone outfitted with WiBotic’s resonant induction wireless charging technology could land on a base station for an automatic recharge with no cords to plug in, no hands on the device to change a battery.
The importance of autonomous recharging only grows with the size of a drone or robot fleet, particularly one that’s expected to operate continuously.
“Batteries and charging, battery intelligence, really needs to be thought about early on and integrated with the system,” Waters says.
He demonstrates a prototype system in the company’s lab space at the back of UW’s CoMotion Headquarters building, where it has leased 10 desks—making it one of the largest companies in the university’s expanding collection of startup incubators.
A transmitter circuit is embedded in a drone landing pad or robotic docking station. It connects to a transmit coil, the shape, size, and weight of which can be customized for specific applications. When the drone approaches, the system detects its presence and a receiver coil mounted on or embedded in the drone begins to receive power. Waters demonstrates this by holding a receiver circuit attached to an LED near the transmit coil. It lights up as soon as it’s in range.
Waters says one of the key advantages of the WiBotic system is that its software can “adaptively tune” the resonance of the transmit and receiver coils—optimizing their frequency to account for changing distances and orientations between them. So if the drone doesn’t exactly stick the landing on the pad, it can still get a good connection to the power source.
“We’re able to, in real time, sense and dynamically control everything to maximize efficiency as these get close,” he says.
Also, the WiBotic software monitoring the relative position of the coils can provide feedback to help improve the precision of autonomous landings.
Indeed, the software is an important piece of the puzzle here.
