ABNORMALITY DISCRIMINATING DEVICE FOR YAW RATE DETECTING MEANS

PURPOSE:To detect abnormalities, including an abnormality that the detected value is too small, over a wide range when only one, not two, yaw rate detecting means is provided. CONSTITUTION:When the front wheel steering angle deltaF of a vehicle 1 is given, the rear wheel steering angle deltaR is given as the sum of the feed-forward quantity from a circuit 5 and the feedback quantity from a circuit 6 corresponding to the yaw rate detected value gammar of a sensor 4. A circuit 9 determines the yaw rate estimated value gammac from the front wheel steering angle deltaF and the vehicle speed V, and a differentiating circuit 10 calculates its change rate (d/dt) gammar. A differentiating circuit 11 differentiates the yaw rate detected value gammar of the sensor 4 and calculates its change rate (d/dt). A circuit 12 determines the absolute value D of the difference between both change rates, and a circuit 13 judges the sensor 4 as abnormal when the deviation D is the reference value R or above. A circuit 7 fixes the feedback quantity of the circuit 6 when the sensor 4 is judged as abnormal.