Patent ID: 9014938
Filing Date: 2015-04-21
Classification: B60K,B60W

Abstract:
1. A travel control apparatus for a four-wheel drive vehicle, comprising: a throttle controller configured to perform throttle opening control of an engine; a driving force distributor configured to distribute a driving force generated by the engine to front wheels and rear wheels; a four-wheel drive controller configured to control the driving force distributor to perform four-wheel drive travel control, the four-wheel drive controller including a failure detector to detect a failure related to the four-wheel drive travel control, the four-wheel drive controller being configured to change a drive control from the four-wheel drive control to a two-wheel drive control and configured to send a first throttle control signal to the throttle controller to reduce a throttle opening in a case where the failure detector detects a failure; a vehicle stability assist controller configured to perform vehicle travel control including an operation control of the throttle controller to maintain vehicle travel stability and configured to send a second throttle control signal to the throttle controller to control the throttle opening; the throttle controller being configured to perform the throttle opening control based on a control signal which corresponds to a smaller throttle opening between the first throttle control signal and the second throttle control signal in a case where the first and second throttle control signals are inputted simultaneously; a requested target drive torque calculator configured to calculate a requested target drive torque to achieve stable travel of the vehicle based on at least a friction limit of the front wheels; an estimated drive torque calculator configured to calculate an estimated drive torque to estimate the driving force generated by the engine; and in a case where the failure detector detects a failure and the four-wheel drive controller changes the drive control from the four-wheel drive control to the two-wheel drive control, the travel control apparatus sending the first throttle control signal to the throttle controller and changing the drive control from the four-wheel drive control to the two-wheel drive control when the estimated drive torque is greater than the requested target drive torque, and the travel control apparatus changing the drive control from the four-wheel drive control to the two-wheel drive control without sending the first throttle control signal when the estimated drive torque is not greater than the requested target drive torque.