Friday morning in a drizzle, I finally experienced the brake anomaly while testing the accelerometer at 160 samples per second:
The Martin Road gate into Redstone Arsenal has speed bump just before the badge check. The first set gave a brief illusion of 'sliding', which is an all too common impression in Huntsville AL. I don't know why but ever since we moved here, every rain is followed by a 'slip and slide' road surface. In fact we lost our '91 Camry on a rain-slick, descending off-ramp. Had it been dry, I probably would have stopped instead of hitting the guy who was stopped at the bottom of the off ramp.
This is a little more detailed view of the speed bump:
Regardless, expanding the data around the first speed bump, I was surprised to find:
I was surprised to see that slight speed increase after integrating the acceleration. Well below the threshold I might detect, the accelerometer data is fairly definitive.
I would be happy to share the spreadsheet and data but at 3.6 MB, it is too large for the 900 KB quota. It can be uploaded from my PriusChat posting in the Technical Forum. I'll also upload it to the YahooGroup "Prius Technical Stuff."
Bob Wilson