Patent ID: 8301353

Claim:
A vehicle motion control device for a vehicle having wheels, the vehicle motion control device, comprising: a using friction circle computing unit for computing a size of a using friction circle in each of the wheels by multiplying a size of an each wheel friction circle indicating a maximum generating force in each wheel tire by a previously computed each wheel using percentage; an each wheel generating force computing unit for computing the each wheel tire generating force and the each wheel using percentage indicating a rate with respect to an upper limit value of a μ-using efficiency in each of the wheels, on the basis of a target vehicle body force and moment indicating a target vehicle body longitudinal force, a target vehicle body transverse force and a target yaw moment, and the sizes of the using friction circles computed by the using friction circle computing means; and a control unit for controlling a vehicle motion on the basis of the computed each wheel tire generating force, wherein the each wheel using percentage is a ratio of the μ-using efficiency in each of the wheels with respect to an upper limit of the μ-using efficiency, and the each wheel using percentage is: i) included as a parameter for computing the each wheel tire generating force, and ii) is determined repeatedly for each of the wheels, and the each wheel generating force computing unit comprises: an each wheel generating force direction computing unit for computing a direction of the each wheel tire generating force minimizing the upper limit value of the μ-using efficiency under the constraint condition that the target vehicle body force and moment are achieved, on the basis of the target vehicle body force and moment and the size of the using friction circle in each of the wheels; an each wheel using percentage computing unit for computing an each wheel using percentage indicating a rate with respect to the upper limit value of the μ-using efficiency in each of the wheels in such a manner as to lower the upper limit value of the μ-using efficiency under the constraint condition that the target vehicle body force and moment are achieved; an each wheel generating force direction correcting unit for correcting the direction of the each wheel tired are generating force in correspondence to the each wheel using percentage computed by the each wheel using percentage computing unit, in such a manner as to achieve the target vehicle body force and moment; and an each wheel generating force corrected computing unit for computing the each wheel tire generating force on the basis of the computed each wheel using percentage, the corrected each wheel tire generating force direction, and a minimized upper limit value of the μ-using efficiency.