Patent ID: 7483821

Claim:
A computer implemented method of deriving tire dynamic element parameters related to lateral force at a slip angle 1 degree, F y and self aligning torque at a slip angle of 1 degree, M z 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, F z ; c) acquiring measured data of lateral force at a slip angle 1 degree, F y and self-aligning torque at a slip angle 1 degree, M z ; d) determining values of at least one linear parameter for the tire dynamic model; e) computing lateral force at a slip angle 1 degree, F y ′ and self-aligning torque at a slip angle 1 degree, M z ′ using the tire dynamic model; f) identifying another value of applied load, F z , 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.