Everybody—from kitesurfers to farmers—will benefit from a small and simple wind meter for smartphones. And the invention is revolutionizing the area of wind data.
“We are in the process of revolutionizing personal wind measurement and the way this information is leveraged,” says DTU student Andreas Bruun Okholm. He has invented a wind meter and a smartphone app making it possible to carry out on-site wind measurements and share this information with others online. He conceived the idea because as a kitesurfer he often wasted hours packing his car with equipment and driving out to the sea only to find that there was not enough wind to put up the kite and head out on the water. It seemed only natural to be able to share this information with other surfers in a simple manner.
”Kites have always fascinated me. I love being able to use the wind forces, be one with nature in an action-packed environment, performing high jumps with a lot of airtime—it really gets your adrenaline pumping. You need wind speeds of 8 to 12 metres per second to really get the pace up, he explains.
Andreas came up with the idea during his BSc project where he studied various options for developing smartphone-based sports accessories, and he concluded that wind speed measurement would be an ideal opportunity. Since then the project has gained significant momentum, receiving a real boost when it won last year's Venture Cup in the ‘Mobile and Web’ category. In partnership with three others, He has now formed the company Vaavud with a view to making personal, smartphone-based wind measurement more accessible. The name Vaavud is inspired by the Nordic gods’ word for wind—Våvud.
Air balloon skippers and sailors
The product was initially intended for kitesurfers, but the areas of application have proven much wider. Sailors, hot air balloon skippers and farmers are just some of the many who have expressed an interest in Vaavud. In addition to the physical wind meter, Andreas has developed algorithms that analyze the signals transmitted by the meter. He has also made smartphone apps—initially for iPhone and Samsung Galaxy.
The actual wind meter is a small plastic bar with a cup at each end. It is connected to the mobile phone’s headset jack. When it is turned by the wind, data is transmitted to the mobile phone. “The drawback of existing handheld wind meters is that they are directional, so you have to point them straight up into the wind. Our wind meter is a so-called cup anemometer, which is not affected by the wind direction,” explains Andreas. “In addition, our meter fits easy in your pocket because it features only two cups instead of the normal three. The measurement uncertainty is expected to be in the same range as with traditional handheld wind gauges, i.e. three per cent.
Magnets instead of electronics
The new wind meter contains no electronics. The genius of it is that it has a small magnet in the rotor. All newer phones have an integrated digital compass. When the phone's magnetic field is affected by the rotating magnets the north indication will swing from side to side, and using a sophisticated algorithm, these oscillations are translated into wind speed.
This technology is not particularly widespread, and according to Andreas it is the first time it is used in connection with wind measurement and smartphones. He is therefore convinced of its promising perspectives: “In a few years’ time, we hope to be the best selling company in the handheld wind meters market. We expect to corner a large share of the current market for handheld measuring devices.
Our wind meter works with a smartphone—which offers far more opportunities—and ours is also much cheaper.” The measurements are shared automatically online, so everyone can benefit from them. The Vaavud team is also developing open software, so other developers can integrate it in their applications.
The long-term plan is to further develop the technology. However, in this semester Andreas Bruun Okholm has chosen to focus more on completing his MSc thesis in construction and mechanical engineering. However, when he hopefully graduates around the New Year, he will have a lot of ideas waiting to be realized. One of them is to extend the wind meter’s range so that you can install it on top of the mast of your boat or on a pole in your garden.