Failure detecting method for steering angle sensor
View Patent ↗Disclosed herein is a failure detecting method for a steering angle sensor that detects a turning angle, turning direction and central position of a steering wheel of a vehicle. It is determined whether the steering angle sensor has failed using traveling behavior of the vehicle, and therefore, the failure of the steering angle sensor is effectively detected even when the steering angle center or the turning angle is incorrectly detected. Also, it is determined whether the steering angle sensor has failed using characteristic differences among pulse signals of the sensor, and therefore, three pulse signals output from the steering angle sensor are effectively detected although any of the pulse signals has failed, whereby the vehicle is stably traveled.
1. A failure detecting method for a steering angle sensor comprising: a rotary disc operatively connected to a steering wheel of a vehicle such that the rotary disc rotates when the steering wheel is turned; a plurality of slits formed at an outer circumference of the rotary disc such that the slits are arranged concentrically with a rotation center of the rotary disc; a central position detecting slit formed at the rotary disc separately from the slits; a first sensor unit and a second sensor unit provided to correspond to two of the slits; and a third sensor unit provided to correspond to the central position detecting slit, the failure detecting method for the steering angle sensor based on a first pulse signal, a second pulse signal and a third pulse signal output from the first sensor unit, the second sensor unit and the third sensor unit, wherein the failure detecting method comprises:
detecting wheel velocity, yaw rate and lateral acceleration of the vehicle;
determining whether the vehicle is being turned based on the detected wheel velocity, yaw rate and lateral acceleration;
determining whether a steering angle decided by the first pulse signal and the second pulse signal during turning of the vehicle is less than a predetermined angle when it is determined that the vehicle is being turned and determining that the first sensor unit and the second sensor unit have failed when the steering angle is less than the predetermined angle; and
determining whether the third pulse signal is phase-changed during turning of the vehicle when it is determined that the vehicle is being turned and determining that the third sensor unit has failed when the third pulse signal is not phase-changed.
2. The failure detecting method according to claim 1 , further comprising determining that the second sensor unit has failed when the first pulse signal is phase-changed but the second pulse signal is not phase-changed in a section in which the third pulse signal is phase-changed.
3. The failure detecting method according to claim 1 , further comprising determining that the first sensor unit has failed when the second pulse signal is phase-changed but the first pulse signal is not phase-changed in a section in which the third pulse signal is phase-changed.