Patent ID: 6896083

Claim:
A four-wheel drive control system comprising: a driving force distribution mechanism for transmitting a driving force from a power source to main driving wheels of a vehicle and capable of distributing the driving force to auxiliary driving wheels of the vehicle; a rotational speed difference detector for detecting a rotational speed difference between the main and auxiliary driving wheels; and a driving force distribution controller for controlling a distribution of the driving force to the main and auxiliary driving wheels on the basis of the rotational speed difference, the driving force distribution controller comprising: a rotational difference driving torque determining section for determining a rotational difference-dependent driving torque on the basis of the rotational speed difference; an output driving torque determining section for determining an output-dependent driving torque on the basis of the output of the power source and the longitudinal load distribution; and a distribution determining section for determining a larger one of the rotational difference-dependent driving torque and the output-dependent driving torque to be the driving torque to be transmitted to the auxiliary driving wheels, wherein the driving force distribution controller determines a driving force to be transmitted to the auxiliary driving wheels on the basis of an output of the power source, a longitudinal load distribution in the vehicle and the rotational speed difference.