| US 7,483,821 B2 | ||
| Tire parameter deriving method, tire cornering characteristic calculating method, tire designing method, vehicle dynamics analyzing method, and program | ||
| Naoshi Miyashita, Kanagawa (Japan); and Kazuyuki Kabe, Kanagawa (Japan) | ||
| Assigned to Yokohama Rubber Co., Ltd, Tokyo (Japan) | ||
| Filed on Sep. 17, 2004, as Appl. No. 10/942,830. | ||
| Claims priority of application No. 2003-327750 (JP), filed on Sep. 19, 2003. | ||
| Prior Publication US 2005/0065666 A1, Mar. 24, 2005 | ||
| Int. Cl. G06F 9/455 (2006.01) | ||
| U.S. Cl. 703—8 | 58 Claims |
| 1. A computer implemented method of deriving tire dynamic element parameters related to lateral force at a slip angle 1 degree,
Fy and self aligning torque at a slip angle of 1 degree, Mz using a tire dynamic model, for computing tire cornering characteristics, the method comprising:
a) identifying initial values of at least one non-linear parameter for a tire dynamic model;
b) identifying a first value of a first applied load, Fz;
c) acquiring measured data of lateral force at a slip angle 1 degree, Fy and self-aligning torque at a slip angle 1 degree, Mz;
d) determining values of at least one linear parameter for the tire dynamic model;
e) computing lateral force at a slip angle 1 degree, Fy′ and self-aligning torque at a slip angle 1 degree, Mz′ using the tire dynamic model;
f) identifying another value of applied load, Fz, and repeating steps c) d) and e) for a number of applied loads;
g) computing a first sum of squared residuals of the measured data of the lateral force and corresponding computed data of
the lateral force, the sum taken over the number of applied loads;
h) computing a second sum of squared residuals of the measured data of the self-aligning torque and corresponding computed
data of the self-aligning torque, the sum taken over the number of applied loads;
i) computing a combined sum of squared residuals as a weighted sum of the first sum of squared residuals and the second sum
of squared residuals;
j) determining if the combined sum of squared residuals is equal to or less than a predetermined value;
k) adjusting the value of at least one non-linear parameter and repeating steps e) through k) until the combined sum of squared
residuals is equal to or less than the predetermined value; and
l) outputting the linear and nonlinear parameters to a display or printer or storing at least one of the parameters in memory.
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