Liquid Robotics announces next generation of Wave Glider sea-going robot
By Ben Coxworth
April 8, 2013
Last December, Liquid Robotics made headlines when one of its Wave Glider aquatic robots completed a “swim” from San Francisco to Australia. It marked the longest distance ever traveled by an autonomous vehicle of any type. The research/surveillance robot was part of a fleet of four that took part in the demo project. One of the others successfully reached Australia later, while the other pair are still on their way to their alternate destination of Japan. Today, the company announced its SV3 – the new-and-improved version of the existing Wave Glider robot.
Besides making the much-publicized PacX trans-Pacific crossing, the company’s “base” model of the Wave Glider (the new version of which is now known as the SV2) has been used by a variety of clients in a number of different projects, since its launch in 2009. “We’ve built over 200,” Liquid Robotics CEO Bill Vass told us. “About a third or so are on missions at any one time. A lot more customers are moving to running 20 at a time instead of one at a time.”
Like the SV2, the SV3 consists of two main parts that are tethered together.
On the surface is a floating surfboard-like “boat,” that contains the sensors which allow the robot to measure oceanographic data such as salinity, water temperature, wave characteristics, weather conditions, water fluorescence, and dissolved oxygen. Also on board are a GPS unit, a heading sensor, transmitters/receivers and other electronics – all of which are powered by built-in solar cells. Below the surface is a winged platform that catches the underwater motion of the waves, allowing it to paddle itself forward, along with the tethered boat.
The SV3 follows the same basic concept as the SV2, but with some key differences.
First of all, it’s bigger. It’s 9.5 feet (2.9 meters) long, and can carry payloads of sensors or other equipment weighing up to 100 pounds (45 kg) – the almost seven-foot (2.1-meter) SV2, by contrast, can only carry up to 40 pounds (18 kg). The SV3 also has more active surface area on the wings of its submerged propulsion platform, plus it can generate and store almost three times as much electricity – this means it can go farther, stay at sea longer, and can power a wider variety and higher number of sensors.
More intriguingly, however, the SV3 additionally features a thrust-vectoring electric motor. Its propeller folds out of the way when not in use, but can be lowered and activated (either autonomously or by satellite remote control) when the robot needs an extra push – such a push might be helpful if it encounters doldrums or cross currents, or if a sudden change in its route is required. The motor is powered by a battery that is in turn charged by the solar cells, as with the other electric components.
A number of improvements have been made in the robot’s capacity to gather, process, store and transmit data, including a new open-source Linux-based operating system. What it all boils down to is the fact that the SV3 can now assess gathered raw data using its own onboard processors, then only transmit the bits that are of interest to the researchers (all of it can still be stored onboard for later reference, however). Using onboard video footage as an example, Vass said “You don’t really want to send back three months of waves, you want to send back ‘I saw a ship’ or ‘I saw a whale.’”
All of the SV3’s electronics and software can be added to the SV2, for existing owners wishing to upgrade. Even the SV2 is a step up from the previous stock Wave Glider, as it offers features such as more onboard processing power, more electrical power, and expanded support for WiFi and cellular communications – the latter feature allows fleets of Wave Gliders to communicate with one another or with neighboring vessels, among other things.
The SV2 can be purchased now, while the SV3 should be available as of the third quarter of this year. Prices aren’t available, although the previous Wave Glider ran at about US$200,000. Fortunately, however, it’s also possible for one SV2 or SV3 to simultaneously carry out multiple assignments for different clients, all of whom simply pay for the service instead of outright purchasing the robot for themselves.
Other higher and lower models, ranging from an SV1 perhaps up to an SV7, are a possibility down the road – depending on clients' needs.
“The ability to more densely collect data over a longer period of time and collect that data in the ocean so you get your answer back, is a pretty compelling thing for most of our customers” said Vass. He can be seen discussing the SV3 in the video below.
Source: Liquid Robotics