Hi,
We have snow in the forecast. My last snow and ice tests failed to show any problems. Regardless, I now have the A0B patch and will do some regression testing.
I can't claim the A0B patch fixes the 'brake pause' because my test conditions require a drizzle to slick the streets. However, I was about to gather some preliminary data from a street by the dog park:
Pothole specifications:
- near side used for ~20 mph, slight braking testing
- length ~7 ft.
- depth > 4-6 inches
Prior to getting the A0B patch to the skid control ECU, I ran multiple, braking tests through the pothole. An accelerometer running at 160 samples per second recorded the data. During the first braking tests, I noticed a distinct drop in the HSI regeneration bar. Typically from ~75% of the bar to ~10-15% of the bar. Regardless, here is typical deceleration graph from the raw data:
I have multiple runs and each shows a decrease in braking force but not the full-up pause seen 2010/02/05:
We know this is both rare and intermittent. Many have reported not being able to repeat the same brake pause over the same bump. During my testing, I tried a run at 25-30 mph and saw no evidence of the regenerative current drop. The Prius documentation mentions 19 mph as a threshold speed in the control laws.
After the A0B patch, there was a change in the deceleration behavior:
I have multiple recordings show no reduction in the braking force. I noticed the regeneration bar did not change before and after the pothole. However, this is not the same brake pause seen in a drizzle rain. Otherwise the brakes felt pretty much as before.
If anyone is interested in the data, send me a PM and I'll forward the raw data.
Bob Wilson