1. Field of the Invention
The present invention relates to a vehicle behavior control apparatus which controls the behavior of a vehicle according to output values of at least a steering angle detection means and a yaw rate detection means.
2. Description of Related Art
Recently, a vehicle is provided with a vehicle behavior control apparatus which controls the behavior of the vehicle by comparing an estimated yaw rate, which is based on a steering angle and a traveling speed of the vehicle, with an actual yaw rate which is detected by a yaw rate detection means. In general, in this vehicle behavior control apparatus, when an abnormality is caused in the yaw rate detection means, there is a fear of deteriorating the normal control of the vehicle behavior. Therefore, in order to reflect the abnormality of the yaw rate detection means on the control of the vehicle, it is important to judge the abnormality of the yaw rate detection means.
Therefore, for example, Japanese Patent Unexamined Publication JP-A-7-149251 discloses a vehicle control unit which judges the occurrence of a failure of a yaw rate detection means when a difference between an estimated yaw rate and an actual yaw rate is increased to a value not less than a reference value. Further, the Japanese Patent Unexamined Publication JP-A-2001-171501 discloses a vehicle behavior control apparatus in which the occurrence of an abnormality of a sensor is judged when a direction of the yaw moment, which is generated in a vehicle according to the deviation between a target yaw rate which is set according to a steering angle and an actual yaw rate, is opposite to a direction of the yaw moment given by a steering operation.
When an abnormality is caused in a yaw rate detection means under the condition that a vehicle is turning and a direction of the output value (the actual yaw rate) of the yaw rate detection means is opposite to an actual turning direction of the vehicle, there is a possibility that the behavior of the vehicle is affected.