| 摘要 |
PROBLEM TO BE SOLVED: To judge the straight advance property using a yaw rate of a vehicle and judge that a steering angle is near zero to make an output of a torque sensor zero forcedly when a straight advance condition in which a vehicle speed exceeds a fixed speed continues for at least a fixed period of time so as to enable accurate and secure zero adjustment. SOLUTION: Steering torque Tn of a vehicle and rotation speeds Vr, V1 of left and right follow-up wheels are detected, a car speed V is calculated as an arithmetical mean value of rotation speeds, and a yaw rateγis calculated as a difference value of rotation speeds. When a condition in which the car speed V exceeds a speed threshold value Vo determined in advance continuous for at least a fixed period of time and an absolute value|γ|of the yaw rate is at most a yaw rate threshold valueρo determined in advance, it is judged that the vehicle is in a straight advance condition and an output of a torque sensor 3 at the time is made zero forcedly to perform zero adjustment. |
