| 摘要 |
PURPOSE:To estimate a mu of road surface accurately even if anti-skid brake control is started on a low mu road by calculating a friction coefficient of a road surface based on the differential value of an average wheel speed or that of a selected rear wheel speed. CONSTITUTION:An ABS controller 26 reads the wheel speeds VFL, VFR, VRL, and VRR of wheels stored temporarily in a memory. Next, based on these wheel speeds, an average front wheel speed VFA and a selected rear wheel speed VRS are calculated. Then it is judged whether or not the average front wheel speed VFA is over the selected rear wheel speed VRS, i.e., VFA>=VRS. When the judgment result here is true, a mu of road surface is calculated based on the differential value of the average front wheel speed VFA, i.e., its degree of deceleration. On the other hand, when the judgment result is false, the muof road surface is calculated based on the differential value of the selected rear wheel speed VRS, i.e., its degree of deceleration. |
