ABS effects: Friction/Drag Factor Measurements
Posted: Mon Nov 15, 2021 10:23 am
Great multi-part (so far) series posted on Facebook by NAPARS
i re-post parts here for those not in the facebook frame of mind
First up, an excerpt from SAE 2010-01-0066
This compares stopping rates for a bunch of different cars and light trucks (they turn out to be statistically the same).
The same car got tested with the ABS operational and also with it disabled (allowing wheels to lock, though they don't always all lock like we might hope). Dick Lambourn determined back in the early 80s that ABS improved stopping rates by about 12%. This research showed that has not changed much.
On average, ABS on dry pavement or concrete (0.82g) is about 12% better than the average skidding value (0.76g).
Both data sets have SD=0.06x, which is consistent with most reported friction testing datasets that include multiple cars on multiple days on multiple surfaces with different drivers and a variety of test equipment (each one of these adds about 0.02g to the standard deviation, and they combine as the root sum of squares).
i re-post parts here for those not in the facebook frame of mind
First up, an excerpt from SAE 2010-01-0066
This compares stopping rates for a bunch of different cars and light trucks (they turn out to be statistically the same).
The same car got tested with the ABS operational and also with it disabled (allowing wheels to lock, though they don't always all lock like we might hope). Dick Lambourn determined back in the early 80s that ABS improved stopping rates by about 12%. This research showed that has not changed much.
On average, ABS on dry pavement or concrete (0.82g) is about 12% better than the average skidding value (0.76g).
Both data sets have SD=0.06x, which is consistent with most reported friction testing datasets that include multiple cars on multiple days on multiple surfaces with different drivers and a variety of test equipment (each one of these adds about 0.02g to the standard deviation, and they combine as the root sum of squares).
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