Speed input maximum frequency
Posted: Wed Sep 17, 2008 3:56 pm
Is there any way around the 2kHz maximum speed input frequency?
Using the ABS sensors we are currently exceeding this frequency. The ABS has 50 teeth, so provides 50 pulses per wheel revolution, so the datalogging limit is 40 revs/sec. The tire dynamic circumference is just over 2 metres, so this gives 80 m/s or 179 mph. For most cars this would not be a problem, but the top speed we've seen so far out of this car is just over 105 m/s (234 mph / 378 kph).
Otherwise I'm going to have to make a pulse divider for the wheel signals.
Using the ABS sensors we are currently exceeding this frequency. The ABS has 50 teeth, so provides 50 pulses per wheel revolution, so the datalogging limit is 40 revs/sec. The tire dynamic circumference is just over 2 metres, so this gives 80 m/s or 179 mph. For most cars this would not be a problem, but the top speed we've seen so far out of this car is just over 105 m/s (234 mph / 378 kph).
Otherwise I'm going to have to make a pulse divider for the wheel signals.