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0 pointskube-system3y ago0 comments

ABS is very simple and only needs to know the difference between the speed of the tire and the speed of the road. It is more complicated systems like ESC (which works with ABS) that need to know about steering inputs.

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rjmunro3y ago

I thought the "speed of the road" was calculated by checking the speeds of the other types, which is trivial if you are going in a straight line, but needs correction if you are steering, hence needs steering angle?

Or is there a simpler way in non-ESC systems?

ilyt3y ago

Simple ABS only cares if the wheel is stationary/goes much slower vs other wheels. Like it wouldn't be perfect but still vast improvement over locking all 4 wheels. Hell, the older ABS systems controlled pair of wheels and activated on both regardless of which one was locking

I'd imagine once they are implementing ESC the ABS also gets the benefit of steering sensor but it is not strictly necessary.

kube-systemOP3y ago

To nitpick, simple ABS is an improvement over locking some of the wheels. It often struggles with preventing a lock of all 4 wheels, because it loses reference for the road speed. A dumb ABS system with just wheel speed sensors can't tell if [0,0,0,0] means all 4 are locked, or if you're stationary.

I don't know as much about the implementation details of modern ESC systems, but I'm guessing this problem is much easier to solve with accelerometer data.

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