Slip angle estimating method and system for a vehicle

摘要

To estimate the readiness of overturn of vehicle accurately at quick timing corresponding to the behavior of an actual vehicle, at first, a roll angle phi 0 and a roll rate phi 0' which indicate an actual tendency of overturn of a running vehicle are measured (calculated). Then, the maximum amplitude A (estimation value) is calculated based on an operational expression for estimating the maximum amplitude A of the behavior estimation value phi (t) of the roll angle phi before damp derived from the following physical model describing the vehicle behavior based on the roll angle phi indicating the overturn tendency of the running vehicle and the estimation value A is set as the overturn parameter X which indicates the readiness of overturn of the vehicle: J phi '' + D phi ' + K phi = F (where, J: roll inertia, D: damper constant, K: spring constant, F: centrifugal force, phi '': roll rate differential value, phi ': roll rate, phi : roll angle).