| 摘要 |
PURPOSE:To accurately and rapidly judge a steering neutral position by a simple circuit constitution, by determining the sub-zone, wherein the integration time contributing to the detection of an origin range becomes max. within a predetermined time in an origin zone, as the origin position. CONSTITUTION:A steering angle sensor 100 is constituted of a rotary disc 1 and photointerrupters 2-4 and slits 1a are opened to the disc 1 at a predetermined angular pitch P. A slit 1b as an origin zone is opened to the disc 1 and the rotary position wherein said slit 1b is opposed to the photointerrupter 4 is set to the origin position of the disc 1. The angle width alpha of the slit 1b is set to the three-angular pitch P of the slit 1a and the origin zone is divided into many sub-zones on the basis of the steering angle position detected by the sensor 100 and the times contributing to the detection of the respective origin ranges of the divided sub-zones are integrated to judge the sub-zone wherein said integration time becomes max. within a predetermined time as the origin position. By this method, the origin position, that is, a steering neutral position can be judged accurately and rapidly by a simple circuit constitution. |
