Safe Speed Forums

A minor aside: could it be better to use a rate of change of (axle?) velocity sensor? The steeper hills will fool a g-force sensor.

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Views expressed are personal opinions and are not necessarily shared by the Safe Speed campaign

That's interesting... I think you're right.

However perhaps we could do the job with a 2 axis g-force sensor, when net vector in the pitch axis is g > 1.

But it'd be simpler to do as you suggest using ABS wheel sensor signals as the starting point. If fact it's then just a bit of software and an extra output from the ABS processor.

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Paul Smith
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The Safe Speed campaign demands a return to intelligent road safety

I like that - using the ABS sensors simply as a loss of axle speed relative to the tarmac - rate of change thereof. Yes - excellent. Come to think of it, there are many many conditions that could be detected from ABS sensor outputs when used in conjunction with other (almost certainly) available snippets of information.

Another topic perhaps... yes, I'll start one - I'm in that sort of mood

I think lots of cars already do that - derive the deceleration from the rate of change of wheel speed. That said, a brake light switch is cheap and reliable! It also has the advantage of working when stationary.

Interestingly, I was in a scatter rally once (at night) and one of the (naughty) competitors had knobbled his brake lights. I was following him and was amazed at the amount of information I (would have!) got from his brake lights!