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Scientists Discover How To Stop Luggage From Toppling On the Race Through the Airport (theguardian.com)
An anonymous reader quotes a report from The Guardian: Scientists have worked out why suitcases tend to to rock violently from one wheel to the other until they overturn on the race through the airport. This most pressing of modern mysteries was taken on by physicists in Paris, who devised a scale model of a two-wheeled suitcase rolling on a treadmill and backed up their observations with a pile of equations and references to holonomic restraints, finite perturbations and the morphing of bifurcation diagrams. Fortunately for non-physicists, the findings can be reduced to simpler terms. For the suitcase to rock it had to hit a bump or be struck in some other manner; the faster the suitcase was being pulled, the more minor the bump needed to set it off. So far, so obvious. But Sylvain Courrech du Pont wanted to know more. Why did a rocking suitcase swerve and make such violent movements that it might eventually topple over? After more treadmill tests and more equations, the answer popped up: because a suitcase's handle pulls from the middle and the wheels are at its sides, the suitcase swerves inwards whenever it tilts up on one wheel. If the rocking overcomes the dampening effect that happens when each wheel touches the ground again, the suitcase will keep on rocking or eventually flip over. In conclusion, the researchers discovered that "when a suitcase starts to rock out of control, the correct response is not to slow down but to pull it faster." The scientists have published their findings in the journal Proceedings of the Royal Society.
Or just get one that has 4 wheels and don't look like a dork
People who tow trailers have known about this for decades.
The handle is also on the same side as the wheels, so when you're pulling it along the weight is above the pivot point between the wheel still on the ground and your hand.
If the handle was on the opposite side from the wheels the weight wouldn't be as high (it would be more in line with your hand and the wheel), so the suitcase would be more stable.
Simple enough to design shock absorbers for the wheels. A proper shock absorber reduces harmonic effects. On vehicles these devices are remarkably affordable and effective. For luggage they could be very cost effective. A simple friction device with a compressed gas cartridge would do the trick. Feel free to design & patent- I don't need the millions it will bring.
...omphaloskepsis often...
As I just posted below - before seeing your comment - those idiots need to hit the accelerator when the trailer starts swerving! Any other maneuver is bound to lead to a bad day.
Speeding up does work.
A second technique that works is to put the car in neutral, effectively decoupling the travel-direction forces transmitted through the hitch. With no more tugging it along, the trailer will settle down (this stops any more energy from being put into the trailer's motion, letting roll-resistance quench out the speed and oscillations). I have done this. Just decouple and coast.
You are correct that hitting the brakes is the absolute worst thing that the driver can do.
I would think that would get you shot, nowadays.
#DeleteChrome
I was about 10.... We were on the way home from a camping trip, and my mom was driving.
Some asshole cut her off, and she instinctively hit the brake. My dad was yelling at her to hit the gas... to no avail. We jacknifed and flipped. That's stuck with me ever since. If your trailer is out of control, speed up.
General Relativity: Space-time tells matter where to go; Matter tells space-time what shape to be.
he only thing preventing this scientific breakthrough was the apparent inability to intersect the community of truckers and physicists despite their relative interdependencies.
There is a huge difference between knowing about something and understanding it. Equations of motion for nontrivial situations can get messy fast, and often beyond a few simple general methods, a lot of cookbook, situation-specific methods are used. Expanding upon those cookbook methods is still useful, and sometimes has applications in other situations.
So what this is telling me is that I need to install coilovers on my suitcase. This way I could adjust the dampening and spring rates to ensure the best response on uneven terrain. I could then even lower it if I wanted, but it's pretty slammed as it is.
Some asshole cut her off, and she instinctively hit the brake. My dad was yelling at her to hit the gas... to no avail. We jacknifed and flipped.
Your parents were the assholes. They either had too much trailer for not having trailer brakes, or the trailer brakes were misadjusted, or the tow vehicle was in some other way inadequate.
"You're right," Fisheye says. "I should have set it on 'whip' or 'chop.'"
Studies (admittedly from the wheeled-luggage lobby) suggest you can buy luggage with wheels and still carry it.
The label 'carry-on' is discriminatory and offensive to the roll-ons. Unfortunately, the deodorant lobby stopped the roll-ons from using that label. I think the carry-ons had something to do with it.