http://listenonrepeat.com/ watch/?v=X2Q_udvSakg#Col - PowerPoint PPT Presentation

http://listenonrepeat.com/ watch/?v=X2Q_udvSakg#Col umbia_FSAE_Metlife_Stadiu m_Autocross

Making R acecars Go Faster with R Matthew Sheridan

Overview 1. Vehicle Dynamics 2. Some Stats 3. Results!

Ways to Make a Racecar Fast

Big Engine

Downforce

Really Good Downforce

Downforce Gone Bad

High Power Low Drag

Lower Drag Even Lower Power

Bolt is not grip limited right now…

Sliding = Slow

Cool, but Slow

Formula SAE Course

We care most about Lateral Grip -Tune to Win

What about weight? No Area Term? Coefficient of Static Friction varies with weight, pressure, temperature, and camber angle

Camber Angle

Want max grip while also having drivable car -Tune to Win

I Don’t Trust Software that’s not R

Printer + Pen + Scanner + MS Paint

Magic Formula y = sy+Dsin(C atan(B(x+sx)-E(B(x+sx)-atan(B(x+sx))))) • y = side force output, x = slip angle input • Sy = vertical shiff, sx = horizontal shift • B = Slope from origin • C = horizontal bounds of sin wave • D = peak value • E = curvature factor

But in a billion dimensions nah….

KNN Regression

Local Regression

Thin Plate Smoothing Spline • Actual MAGIC! • Minimizes cross-validated residuals while also minimizing number knots in splines • MGCV Package Simon Wood

Nonlinear Least Squares on Magic Formula

Trying GAM Y = s(SA) + fz * SA^n

Loess, Locfit

More Locfit Turn nearest neighbor value to n = 0.1

Play with NN

KNN Regression

Locfit

GAM

Comparison of Tires

Camber Interpolation

Why don’t you try interpolating FZ too?

Scale the Z

Questions? A.matthew@Columbia.edu