Patent ID: 8160816

Claim:
A vehicular behavior determination device which determines a behavior of a vehicle, comprising: a first arithmetic processor, which determines a parameter representing the behavior of the vehicle; a second arithmetic processor, which calculates a posture vector representing a posture of the vehicle in a global coordinate system on the basis of a determination result determined by the first arithmetic processor; and a third arithmetic processor, which calculates an angular velocity vector representing an angular velocity of the vehicle around each of 3 orthogonal axes in a vehicular coordinate system on the basis of a temporal variation mode of the posture vector calculated by the second arithmetic processor; wherein the second arithmetic processor calculates an i th posture vector (i=1, 2, 3) which represents a posture of each of the 3 orthogonal axes of the vehicular coordinate system in the global coordinate system as the posture vector; and the third arithmetic processor obtains a rotational main axis vector which represents a direction of a rotational main axis in the global coordinate system by combining 3 rotational axis vectors for making a previous i th posture vector match with a current i th posture vector, calculates a first-order angular velocity vector which represents an angular velocity of the vehicle around each of the 3 orthogonal axes in the global coordinate system on the basis of the obtained rotational main axis vector, the previous i th posture vector and the current i th posture vector, and thereafter calculates a second-order angular velocity vector which represents the angular velocity of the vehicle around each of the 3 orthogonal axes in the vehicular coordinate system as the angular velocity vector on the basis of the first-order angular velocity vector and the i th posture vector.