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Electric Motorcycle Inventor Crashes at Wired Conference
not5150 writes "The inventor of the electric 'KillaCycle" motorcycle was taken to the hospital for x-rays after demonstrating the vehicle to reporters. Bill Dube, a government scientist during the day and bike builder at night, attempted a burnout in front of the Los Angeles Convention Center during the Wired NextFest fair. Fueled by the "most powerful" lithium-ion batteries in the world, the bike accelerated uncontrollably into another car. There's a video interview (thankfully before the crash) and footage of Dube crashing."
While the slashdot effect kills the video, there's some pictures and comments at gizmodo
Well its not like you can only apply the power gradually like a petrol engine.
Of course you can. Do you have an electric fan? Does it always run at full speed? Or is there a little switch that lets you adjust the fan speed?
My understanding is that when you turn an electric engine on, that's it, full power full torque.
No. Electric motors can do that (which is nice in many applications), but they don't have to do that. It depends on how much voltage/current goes to the electric motor, and it's pretty easy to control voltage & current.
from the comments on the linked page:
I wasn't wearing a helment, because we did not intend the bike to even move!
We were spinning the tire in soapy water. The tire unexpectantly gripped, (water ran out?) and launched the bike. I couldn't get it shut down as quickly as I would have liked. I had to release the front brake to fully untwist the throttle. I then managed to slow it down to about 20 mph.
The positive message here is that when we crunched the battery pack, NOTHING happened. No smoke. No flames. Not even sparks. Not only are these cells more powerful, they are are the safest possible for automobiles.
Also, there was NO ONE in front of the bike or in the possible trajectory of the bike.
Bill Dube
You're erroneously assuming a constant acceleration: real-world dragstrip acceleration-time plots are anything but linear.
As to the time, 0-60 in 1 second is standard for drag cars or bikes running in the 7s on the quarter mile.
1/4 mile times like that are pretty good for an electric vehicle though.
There are a lot of videos of the thing in action at http://video.google.com/videosearch?q=KillaCycle. The thing is clearly not a scooter
It's really a bummer that he decided not to wear a helmet.
Well its not like you can only apply the power gradually like a petrol engine. My understanding is that when you turn an electric engine on, that's it, full power full torque.
You can vary the amount of power sent to the motor, it is also possible to have motors with switchable windings to give different torque and speed settings. In the case of a vehicle such as a car or motorbike an electric motor can be connected via the same sort of gearbox you'd use with an internal combustion engine. Indeed the only real difference between a regular motorcycle and an all electric one is that the latter wouldn't need a starter.
Yes and no.
You can't easily apply gradually more power with high-power engines running on AC.
There are numerous tricks like switching configuration of the coils, using high-power thyrystors etc. You can't just put some resistance because it would be enormously wasteful. Some railway engines use "convert 1-phase AC from the wire to DC, then convert back to three-phase AC of desired frequency" making them actually more efficient than running on 1-phase AC straight from the wire.
But not in this case. The batteries produce DC. They can be switched one at a time to limit voltage(->torque) if it's a DC motor, or the conversion to AC can be freely configured providing frequency (->RPM) just as desired if the motor is AC.
(also note using all kinds of resistors, pots and other "power drains" for limiting current/voltage when such powers are in use, are useless - they would have to dissipate (and waste) enormous amounts of power. Devices that limit the "average" voltage by dutycycle method ( x% of a milisecond on, 100-x% of a milisecond time off => x% power) are much better but not every kind of end-target device can accept this kind of power, plus it generates lots of electromagnetic noise from all the instant on-off action )
Simply put, getting limiting voltage by a half in a 5V 10mA DC configuration is trivial - wasting 0.25W of power is not a problem. In 500V 10A DC configuration is very tricky. Dissipating 2500W is not really an option.
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You can have slip within the electric motor, so it can behave like an electromagnetic clutch. This can be pretty handy:
On diesel railway locomotives, they have a diesel engine that generates electricity, which is then used to power electric motors on the wheels. One reason for this arrangement is that using electric motors like this means you don't need a clutch and it's more compact than a fully mechanical transmission for such huge power would be.
I don't know if you can make the roads safe for motorcycles of any kind, unfortunately. I was a long time rider and cycle enthusiast. I had lots of good safety gear, lights all over my bike, etc. I had taken safety courses with hands on crash avoidance scenarios. Last year an idiot woman in an SUV launched herself from a side road like she was on a suicide mission to get across the four lane divided highway where I was riding. She crushed my leg which they nearly had to amputate; broke my ribs which consequently punctured my lungs; ripped a hole in my small intestine; tore my abdominal wall to the point where I now have a piece of kevlar mesh holding my organs in on the right side. It's been a year and a half and I almost walk normally now. I was wearing a full face helmet that hit the ground repeatedly as I flew through the median.
I got a twelve day stay in an ICU, four major surguries, four months in the hospital, a year of rehab, more than a half million US dollars in medical bills, and pain that I would never wish on anyone. She got a ticket for failure to yield right of way and a new SUV.
If you want to ride a bike on the highways in the U.S. beware that the consequences of the bad judgement of the drooling idiots you share the road with is extremely high. The helmet will ensure that you remain concious throughout the ordeal... if you are lucky... and if you aren't, at least your wife, kids, parents, or whatever will be able to have an open casket funeral.
A little misunderstanding? Galileo and the Pope had a little misunderstanding...