Abstract: A driving force distribution apparatus includes a basic distribution ratio calculator, a servo controller, and an adjuster. The basic distribution ratio calculator is configured to calculate a basic distribution ratio between a front driving force for front wheels and a rear driving force for rear wheels based on loads exerted on the front and rear wheels of a vehicle. The servo controller is configured to correct the basic distribution ratio so as to increase or decrease the basic distribution ratio based on a deviation between a target value of a rotation difference between the front and rear wheels and a measured value of the rotation difference between the front and rear wheels. The adjuster is configured to perform adjustment so that the rear driving force calculated based on the basic distribution ratio corrected by the servo controller does not exceed a total driving force.

Abstract: A driving force distribution control apparatus for a four-wheel drive vehicle includes a theoretical value calculator, a normative value calculator, and a servo controller. The theoretical value calculator is configured to calculate a primary rotational speed theoretical value of primary drive wheels and a secondary rotational speed theoretical value of secondary drive wheels based on a steering angle, a vehicle speed, a yaw rate, and a slip angle of the four-wheel drive vehicle and configured to calculate a rotational difference normative theoretical value indicating a difference between rotational speed theoretical values of input and output shafts of a drive force distribution apparatus using the primary rotational speed theoretical value and the secondary rotational speed theoretical value.

Abstract: A driving force distribution control apparatus for a four-wheel drive vehicle includes a basic distribution determination device and a servo controller. The basic distribution determination device is configured to determine basic distribution of a driving force to secondary drive wheels in accordance with the driving force and driving conditions of the vehicle. The basic distribution determination device includes a tire force limit determination device and an arithmetic device. The tire force limit determination device is configured to calculate a tire required acceleration in accordance with the driving conditions of the vehicle and configured to output a basic distribution adjustment signal having a characteristic that gradually decreases a ratio of the basic distribution for the secondary drive wheels to zero in a transient region in which the calculated tire required acceleration is lower than a predetermined threshold value.

Abstract: A driving force distribution apparatus includes a basic distribution ratio calculator, a servo controller, and an adjuster. The basic distribution ratio calculator is configured to calculate a basic distribution ratio between a front driving force for front wheels and a rear driving force for rear wheels based on loads exerted on the front and rear wheels of a vehicle. The servo controller is configured to correct the basic distribution ratio so as to increase or decrease the basic distribution ratio based on a deviation between a target value of a rotation difference between the front and rear wheels and a measured value of the rotation difference between the front and rear wheels. The adjuster is configured to perform adjustment so that the rear driving force calculated based on the basic distribution ratio corrected by the servo controller does not exceed a total driving force.

Abstract: A travel control apparatus for a four-wheel drive vehicle includes a throttle controller, a driving force distributor, a four-wheel drive controller, a vehicle stability assist controller, a requested target drive torque calculator, and an estimated drive torque calculator. In a case where a failure detector detects a failure and the four-wheel drive controller changes a drive control from a four-wheel drive control to a two-wheel drive control, the travel control apparatus sends a first throttle control signal to the throttle controller and changes the drive control from the four-wheel drive control to the two-wheel drive control when an estimated drive torque is greater than an requested target drive torque, and the travel control apparatus changes 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.

Abstract: A driving force distribution control apparatus for a four-wheel drive vehicle includes a theoretical value calculator, a normative value calculator, and a servo controller. The theoretical value calculator is configured to calculate a primary rotational speed theoretical value of primary drive wheels and a secondary rotational speed theoretical value of secondary drive wheels based on a steering angle, a vehicle speed, a yaw rate, and a slip angle of the four-wheel drive vehicle and configured to calculate a rotational difference normative theoretical value indicating a difference between rotational speed theoretical values of input and output shafts of a drive force distribution apparatus using the primary rotational speed theoretical value and the secondary rotational speed theoretical value.

Abstract: A driving force distribution control apparatus for a four-wheel drive vehicle includes a basic distribution determination device and a servo controller. The basic distribution determination device is configured to determine basic distribution of a driving force to secondary drive wheels in accordance with the driving force and driving conditions of the vehicle. The basic distribution determination device includes a tire force limit determination device and an arithmetic device. The tire force limit determination device is configured to calculate a tire required acceleration in accordance with the driving conditions of the vehicle and configured to output a basic distribution adjustment signal having a characteristic that gradually decreases a ratio of the basic distribution for the secondary drive wheels to zero in a transient region in which the calculated tire required acceleration is lower than a predetermined threshold value.

Abstract: A travel control apparatus for a four-wheel drive vehicle includes a throttle controller, a driving force distributor, a four-wheel drive controller, a vehicle stability assist controller, a requested target drive torque calculator, and an estimated drive torque calculator. In a case where a failure detector detects a failure and the four-wheel drive controller changes a drive control from a four-wheel drive control to a two-wheel drive control, the travel control apparatus sends a first throttle control signal to the throttle controller and changes the drive control from the four-wheel drive control to the two-wheel drive control when an estimated drive torque is greater than an requested target drive torque, and the travel control apparatus changes 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.