Dainese smart ski airbag ready for prime time
By C.C. Weiss
February 25, 2014
We've been following the development of the Dainese D-Air Ski for just over three years, and the company has now revealed a near-competition-ready prototype to the world. Using a clever array of sensors, the protective ski garment detects a crash and rapidly inflates around the skier's upper body to protect from injury on the way down.
The warm temperatures and poor snow conditions of the 2014 Winter Olympics highlighted how unpredictable downhill skiing can be. As a skiers barrel downhill at 80 mph (129 km/h), barely able to cut around the competition gates, all it takes is an unexpected soft, slushy patch to send them careening off course. Sometimes that just means a slower time or disqualification, but sometimes it means an out-of-control, potentially devastating fall or crash.
With these types of racing crashes in mind, Dainese joined forces with the International Ski Federation (FIS) three years ago, aiming to adapt its motorcycle airbag protection technology to the sport of ski racing. That process involved the meticulous collection of data for the creation of a new algorithm.
The algorithm is the heart of the D-air system, allowing it to differentiate between the normal forces involved in ski racing and the forces involved in a serious fall. Dainese pulled data from 238 descents and 700 minutes worth of ski time in order to develop an algorithm that can differentiate between forces like a jump landing or hard turn and crash-level forces.
"The D-air Ski algorithm deploys the system in all cases where the skier's body performs twists which go beyond what would be considered normal race dynamics, for example forward, rear or lateral rotations during a jump or rolling over on the piste," Dainese explains. "The algorithm only inflates the system when signals received from 7 sensors exceed a preset threshold. For example, in the event of a low speed slide not followed by rolling, the algorithm can decide not to inflate the airbag."
The actual force monitoring is performed by a set of three accelerometers, three gyroscopes and a single GPS. Readings from the sensors are constantly being analyzed through the algorithm-driven microprocessor, and should they fall outside the threshold, they trigger the activation of the 8-liter airbag by way of a "cold gas" inflation mechanism.
The airbag blows into shape, wrapping around the skier's upper body. It protects his or her chest, shoulders, collarbones and cervical vertebrae. Dainese says it absorbs up to 61 percent of the impact force. The entire process, from crash detection to full inflation, happens within 100 milliseconds during the most violent falls.
The 1.8-lb (800 g), stretch-fabric D-air Ski is worn like a slim backpack, over the standard back protector but underneath the racing ski suit. It has an on/off switch on the front and an indicator LED for battery status. A USB serves to hook the D-air up for recharging the lithium-polymer battery and uploading data from its onboard memory.
While the general idea and the sensor set are the same as when we first looked at the concept three years ago, Dainese explains that the pneumatics hardware, ergonomics and aerodynamics of the design have evolved drastically during the development period.
After analyzing trauma data from FIS studies, Dainese reworked its older design to better protect vulnerable areas. Because back protectors have become standard equipment, Dainese was able to adjust the airbag off the back for fuller frontal protection without any added material or weight.
Working the proper aerodynamics proved particularly tricky because ski racers obviously do not want to wear anything that would slow them down. On the other hand, improving the skier's overall aerodynamics threatened to infringe upon competition rules. Dainese used Ferrari's wind tunnel in Maranello to ensure that the physical design of the back-mounted D-air Ski doesn't alter the skier's aerodynamics one way or the other.
Dainese also performed safety testing to ensure that the inflation of the airbags does not present a hazard for the skier. It also ensured that the placement of the components themselves, particularly the gas canister, does not add to the injury risks of a fall.
With all that research and testing behind them, and a near-competition-ready prototype in hand, Dainese and FIS presented the D-air Ski in Kitzbuhel, Austria and ISPO Munich last month.
"More than three years have passed since we approached Dainese regarding a possible cooperation on developing an airbag system for alpine ski racers," Gunter Hujara, FIS Chief Race Director, World Cup Men's explained at the Kitzbuhel reveal. "We had some information about such system being available in motorcycle racing and I had positive reports from some motorcycle competitors."
"We have worked on this project a lot and the most difficult thing was defining the algorithm and finding the exact moment when an athlete is no longer in control and is no longer able to handle the situation. We installed the data collecting system in our training runs and at the end this was very helpful as we got a clearer idea of what really happens during an alpine ski racing run. The D-Air System seems to be almost ready now; we did some last tests recently and we had a meeting with the coaches in Val Gardena where the latest prototype was presented."
It seems like the unveiling was rushed a bit in order to meet the previously announced deadline of the 2014 Olympics. The AFP reported prior to the Olympics that the D-air would not be used in the Games because it was not quite ready for competition use. While the D-air missed the actual skiing of the Olympics, Dainese did showcase it as part of a seminar in Sochi.
Dainese and the FIS plan to continue collecting data and refining the Ski algorithm moving forward. Dainese mentions the possibility of designing additional protection pieces for other parts of the body and says that D-air could influence "possible interactions between skis and bindings."