As a car rounds a turn, a force exists called centripetal acceleration, which is an outward inertial force that is counteracted by the force exerted between the road and the tires. Once the centripetal acceleration force (expressed in newtons) overcomes the traction force (also expressed in newtons), the car breaks free and slides. My idea is to create a unit for a car that calculates a car's current centripetal acceleration along with the maximum traction force and display them together, so as to give the driver a numerical representation of exactly how much grip he has around a turn.

You see, centripetal acceleration is determined by the weight of the car, the speed of the car, and the radius of the turn. Traction is determined by the coefficient of friction between the tires and the road. If all this information could be garnered on the fly, the unit could easily calculate the exact forces acting on the car.

Sensors in the suspension could determine, at that moment, the total weight of the car, both mass and the added force from aerodynamics. The radius of the turn could be deduced by the pitch of the front wheels, leaving only speed to be deduced, which is obviously simple. The most challenging aspect is finding the coefficient of friction of the tires and the road. TCS may already gather this information; if not, the unit should be able to figure it out from data from the car's ABS system.

Applicability: knowing right when you're about to lose traction is invaluable on the track. Cars could be pushed right to limit around corners, improving lap times. It also has uses as a safety feature, a kind of "early warning system" to be used in conjunction with DSC/TCS to prevent skids rather than just attempting to correct them.

What do you guys think? Am I the next American Inventor?

 

Possible flaws:

Large amount of sensors and wiring needed would limit it to OEM or professional installation.

Difficulty in displaying two constantly updating numbers in a way that would be readable and useful during driving. Maybe two wave-like lines on the display would be the best way; when the bottom line crosses the top, you're spinning. Maybe on a HUD system.

 

heres a cheaper version, hang a weight from your rear view mirror

 

It's already been done, and you should be able to feel it.

 

Just a thought, but when I'm going round a corner, I kinda like to look where I'm going, not at some blnky light thing on the dash.

 

I think we should just cut to the chase and design cars that drive themselves for those incapable of driving for themselves. That's what it all comes down too.

It's already possible to monitor traction circles and slip angles on race cars. And, any race car driver worth a damn can monitor them by feel. If you have to have guage telling you your slip angles and whatnot, you're slow. Far to slow to be a race car driver. Find another hobby, knitting perhaps.

 

with that device, you will take the fun out of driving.

 

Um, whats a gtech for?

 

Hey ! were almost there! What do u think AWD is and infread beams adjusting cruise control automatiacly.

Now, all we need is a beam in the rear of the car to monitor traffic behind us and have the computer automaticly adjust the space between the cars by changing speed.

 

I was taking this from an aviation standpoint. I didn't imagine this gauge being much different in purpose than an L/V-Max gauge in an airplane (lets you know when you're going to stall). After all, the #1 rule of instrument flying is not to trust your own senses.

Someone explain to me how conveying more information to the driver takes the fun out of it. It wouldn't limit performance or make corrections in any way, just display information. I wonder if people said the same thing when speedometers were introduced, because after all, any good driver should be able to feel how fast he's going!

 

Real-time, I go through turns too fast for something like that to be any help. But recording that information so that I can view it after a run might be of some value.

 

First, weight has nothing to do with centripetal acceleration. It's a result of it, not a factor in determining it.

Second, determining the coefficent of friction of the road to tire contact patch is basically impossible until you actually break the tire loose. Once the tire breaks loose, you're there, and you may be hoping the DSC is still turned on. The friction coefficent changes with road surface, tire pressure, tire temp, and a million other little things.

Third, what you want in an airplane is an Angle of Attack gauge. Velocity, weight, etc are all secondary to AoA for when the plane will stall. Wings stall at a given AoA, not a constant speed or anything else.

All you really want is slip angle. This is the closest thing you can find to see how much turn traction you have left. All the sensors to do this are already in the car- gyros, accelerometers, speed sensors. They're all sitting there, waiting, ready to kick in and save your butt. All you really want is a display that shows the slip angle growing, which should theoretically just be SW. You could progam the ECU to display it on the oil pressure gauge and make it worth something!

 

I'm pretty sure the calculation for centripetal force (which is really what he is talking about force needed to overcome the friction of the tires) is F=mv/r so M being mass, weight does have something to do with it.

(Please don't argue weight isn't the same as mass - for this discussion it doesn't matter)

And I don't know about next American Inventor but it sure sounds like someone is taking first year physics.

 

Going along the lines of Paul_in_DC, I think an on-board system like this that keeps logs of useful data like g forces, weight shift %, and tire loads during a track run would be a lot more useful than real-time data. The data could be graphed and used to improve driving technique or tune your suspension. Maybe even something like maybe a GPS receiver could be added so that acceleration, velocity, distance traveled vs time can be accurately calculated.

 

Already been done, just one example:

http://www.extremegeez.com/

Combined with GPS:

http://www.trackvision.net/

 

The comment was "centripetal acceleration" not "centripetal force." Acceleration has nothing to do with the mass, while the resulting force does.

 

How about aswell as having the HUD system, you also make it have like a beep or buzzer when the grip is about to be at a point that you spin out. I dont know, just a thought since people don't want to take their eyes off the road