Coming to your bicycle: wireless braking?
For the computer scientist, whose mission in life is to make things safer through well-prepared wireless systems, cycling is just a hobby.
But when he helped develop a braking system for bicycles that needs no cables and is operated by a sensor in the handlebar, the cycling industry took notice.
“This is a playground for us,” Hermanns told CNN by phone. “I never thought someone would be seriously interested in this.”
He chose a bicycle because it was an inexpensive, easy-to-build platform that could help him and his team test their calculations. And it was much safer to crash than say a car or a train. After his work was announced, the calls from companies associated with biking started coming.
Their prototype is cruiser-style bike that many commuters ride to work or around town. The rider puts pressure on the sensor, which signals a receiver on the frame’s front fork.
The harder the grip, the more pressure the receiver tells the brakes to apply. A battery supplies electricity to the system, which include other sensors receiving information from the brakes. The rear brake is operated with the foot by cranking the pedals in the opposite direction.
The wireless brake works with 99.9999999999997 percent reliability, according to a news release from Saarland University.
“That is not perfect, but acceptable,” Hermanns said.
Hermanns doesn’t see this as something riders in the Tour de France will be adding anytime soon. The receiver/battery combination weighs too much at this point.
“Until you can buy it in a shop, this will take several years,” he said, adding it will probably take five years to produce something light enough to work commercially. He also thinks he can make his system work with ABS brakes instead of the “relatively simple” disc brakes the test bike uses.
What Hermanns wants to test is not bike-braking but the configuration of a new wireless system. The bike experiments have shown him that fine tuning can greatly improve the reliability of the network, he said.
“We can model and analyze these models and then put this new practice on the bike,” he said.
His research might lead to increased use in more complex systems — in European trains, for example.
Hermanns said a good wireless system will keep the trains moving better. Currently, tracks have systems that count the number of axles that travel over them. One section of track counts up, another counts down. When the total zeroes out, the system decides it’s safe for another train to come through.
But if the count is wrong, the system would force some trains to be emergency-braked to a stop. And it takes a while to get a train moving again.
Hermanns said a wireless system could allow more communication between track and trains, and prevent such unnecessary braking. Sensors will also measure brake performance, but unlike his bike prototype, the train brakes would not be operated wirelessly.
“Wireless communication, hard real-time requirements and safety criticality do not go together well,” Hermanns and his colleagues write in their paper about wireless technology.
But Hermanns believes that safety-critical wireless systems – whether on a bike or another mode of transport – will evolve and improve. And that is what he’s really after.
By Steve Almasy