| 摘要 |
PURPOSE:To make it possible to accurately detect car speed with good response, by performing the movement averaging or addition of a car speed input pulse at every one rotation. CONSTITUTION:A read switch 5 is turned ON and OFF every when the pole of a magnet 4 passes and constitutes a car speed sensor along with the magnet 4. A car speed detecting circuit 6 is constituted of a microcomputer for inputting the pulse from the car speed sensor. When a pulse is inputted to the car speed detecting circuit 6 as shown by R1, R2... from the car speed sensor and pulse cycles are set to t1, t2..., a car speed can be detected with good response if operated by said pulse cycles t1, t2... themselves but, because the error of pulse intervals due to the irregularity of the magnet 4 or an error due to a skipping phenomenon is contained in this system, an accurate car speed can be detected. Because the information of an accurate rotation number is outputted from the generation cause of said errors at every one rotation of a wire 31 or the magnet 4, an accurate car speed can be detected by averaging or addition at every four cycles. |
