			PL-Tirefit

PL-Tirefit is a freeware for the identification of the Magic Formula (MF) coefficients (also known as Pacejka's parameters) from tire data measurements.

The Magic Formula is a set of analytical formulations that provides an easy way to model the relation between the force components (lateral force, self-aligning torque, longitudinal force) at the tire/ground interface and the slip parameters (slip angle or slip ratio).

Many systematic measurements are required to obtain the MF parameters within an optimization loop, also called curve-fitting method.

These measurements must be priorly performed with special test benches (drum test benches or tire test tracks).

That is the purpose of PL-Tirefit to support the designers by automating the difficult and delicate task of parameter identification.

The use of efficient optimization algorithms such as Levenberg-Marquardt or Differential-Evolution made it possible.

PL-Tirefit is available for free with no limitations.

Download PL-Tirefit v1.0

A password is required to run the setup program. Click here to get the password (absolutely free !).

Screen capture of PL-Tirefit

Sample test : truck tire 315 80 R 22.5

(more tire identifications here)

References for tire data :

“Heavy truck handling performance analysis in vehicle test computer simulation”

Tire Sci. and Technol., Volume 25, Issue 2, pp. 119-136 (April 1997)

C. Schröder and A. Duchow






Lateral force F_y : Measurements (blue); Fitted MF model (red) obtained with 4 load-cases (from 20000 N to 50000 N)			Self-aligning torque M_z : Measurements (blue); Fitted MF model (red) obtained with 4 load-cases (from 20000 N to 50000 N)

Corresponding MF parameters

R0=0.537

[NOMINAL LOAD]

Fz0=35224.69846

[PARAMETERS FY]

Phy1=0

Phy2=0.03461

Phy3=0.25

Pvy1=0.00345

Pvy2=-0.2431

Pvy3=0.15

Pvy4=0

Pdy1=0.89436

Pdy2=0.57457

Pdy3=0

Pcy1=0.97077

Pey1=0.55875

Pey2=3.01424

Pey3=0.00108

Pey4=0

Pky1=17.30243

Pky2=4.48963

Pky3=0

[PARAMETERS FX]

PCx1=0

PDx1=0

PDx2=0

PEx1=0

PEx2=0

PEx3=0

PEx4=0

PKx1=0

PKx2=0

PKx3=0

PHx1=0

PHx2=0

PVx1=0

PVx2=0

[PARAMETERS Mz]

QBz1=4.29957

QBz2=9.16986

QBz3=9.70353

QBz4=0

QBz5=0

QBz9=0

QBz10=0

QDz1=-0.08228

QDz2=0.02702

QDz3=0

QDz4=0

QDz6=0

QDz7=0

QDz8=0

QDz9=0

QEz1=-10.66503

QEz2=54.79309

QEz3=-77.01057

QEz4=0

QEz5=0

QHz1=0

QHz2=-0.12744

QHz3=0

QHz4=0

QBCz1=1.18953

OTHER TIRE IDENTIFICATIONS HERE