Advics Co., Ltd.

Daihatsu Motor Company, Ltd.

Tokio Yakushijin

Toshihisa Kato

Masanobu Fukami

Junya Nagaya

When the absolute value of the steering angle equals or is greater than a prescribed angle, a vehicle motion control apparatus sets a control gear ratio so that when an estimated vehicle-body speed is equal to or greater than a prescribed value, the control gear ratio becomes a value equal to or greater than a certain value and which increases with estimated vehicle-body speed as the absolute value of the steering angle increases. When the estimated vehicle-body speed is less than the prescribed value, the control gear ratio becomes a value not greater than the certain value and which decreases with estimated vehicle-body speed as the absolute value of the steering angle increases. The apparatus then calculates a target yaw rate making use of the control gear ratio, and controls a braking force applied to each wheel so that the actual yaw rate coincides with the target yaw rate.

Motion control apparatus for a vehicle

A control of a vehicle motion control deviceis as follows during an oversteer restraining control. Specifically, when tire inflation pressure is appropriate, the device sets braking force exerted on each of front and rear wheels at the outer side of the turning direction so as to be reference braking forces Ffand Fr, that are generated when an absolute value of a lateral acceleration deviation &#x394;Gy is not less than a reference value aand that respectively increase up to an upper limit value ff and upper limit value fr in accordance with the increase in the absolute value of the lateral acceleration deviation &#x394;Gy. On the other hand, when a tire inflation pressure of one of the front and rear wheels at the outer side of the turning direction is lowered, the device sets the braking force, such that the braking force starts to be generated from when the absolute value of the lateral acceleration deviation &#x394;Gy is smaller than the reference value aby an amount in accordance with the reduction in the tire inflation pressure and that the upper limit value of the braking force with respect to the wheel whose tire inflation pressure is lowered is decreased by an amount in accordance with the reduction in the tire inflation pressure and that the upper limit value of the braking force with respect to the wheel that is not the wheel whose tire inflation pressure is lowered is increased by an amount in accordance with the reduction in the tire inflation pressure.

Vehicle motion control device

A motion control devicefor a vehicle exerts braking force only on the rear wheel at the inner side of the turning direction for generating a yawing moment on the vehicle only in the turning direction of the vehicle when an absolute value of an actual lateral acceleration Gy is not more than a value Gyth, i.e., when there is a small possibility of the occurrence of an excessive roll angle on the vehicle body, in case where the turning state of the vehicle is the understeer state. On the other hand, it exerts braking force not only on the rear wheel at the inner side of the turning direction, but also on the front and rear wheels at the outer side of the turning direction for generating a yawing moment in the direction opposite to the turning direction too, when the absolute value of the actual lateral acceleration Gy exceeds the value Gyth, i.e., when there is a great possibility of the occurrence of the excessive roll angle on the vehicle body, in case where the turning state of the vehicle is the understeer state.

Growing community of inventors

Ikeda, Japan

Tokio Yakushijin