| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a wheel speed detection apparatus which detects a wheel speed at very low speed accurately.SOLUTION: A wheel speed detection apparatus includes: a wheel speed sensor 2 which detects an object integrally rotated with wheels of a vehicle; and a wheel speed detection unit 3 which detects a wheel speed at every operation timing in a predetermined period, on the basis of a wheel speed pulse formed by waveform-shaping a detection signal from the wheel speed sensor 2. The wheel speed detection unit 3 includes: a first oscillator 7 which outputs a first clock having a frequency changing according to acceleration; and a wheel speed calculation unit 9 which determines current acceleration from the number of pulses of the first clock counted in a current cycle from the previous operation timing to the current operation timing, when the period of the wheel speed pulse is long and the wheel speed cannot be calculated based on the wheel speed pulse at the current operation timing, to correct the wheel speed detected at the previous operation timing with the determined current acceleration, thereby calculating a wheel speed at the current operation timing.</p> |
