Drivetrain Reference Tables - 2008

[Vanquish]

I'm looking at the drivetrain reference tables provided in the KOP. Since we do not have a rug avaliable to test our autonomous mode we have to resort to calculating it beforehand as best we can and then modifying it at the competition.

The table lists the COF (coefficient of friction) for a variety of wheels. Is this the COF for the wheels on the rug such as the one that will be used at the regionals or is it something else?

If it isn't related can anyone give me pointers as to how I should go about calculating how far we will go in autonomous when we are on the competition rug? (ie: calculate for it on a smooth surface then add 5 feet to it, etc.)

[MrForbes]

The coefficient of friction is important if you have the wheels slipping on the floor...usually that is not a problem if you limit your acceleration, and the floor is not extremely slippery.

Any piece of short nap carpet should be fine for testing. The carpet on our high school hallways is very similar to the carpet on the competition fields.

[kramarczyk]

The CoF that IFI provides are
Wedgetop: 1.2 and 0.00905 pounds / Sq Inch
Roughtop: 1.3 and 0.01025 pounds / Sq Inch

AndyMark (http://www.andymark.biz)provides detail for his product on it's individual pages
The kit wheels provided by them are
Tangental skidding resistance: 0.65
Resistance from a sideways push: 0.9

As far as laying out auton goes... I am assuming that you are running open loop, so you may want to check out JVN's earlier tools http://www.chiefdelphi.com/media/papers/1676
Specifically the gearbox modeling sheet. The Position versus Time plot should get you pretty close for straight line driving.

Since you don't have carpet to test on are you sure you can turn???

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I wish I had a dollar for every time I recommended that spreadsheet... Great piece of work John.