2010 brake system

[garygid]

A very brief skid (for me, 1 foot on a wet pedestrian crosswalk line) or
a "sufficient" bump apparently triggers the skid-sensor, which results
in the regen braking being turned off for about a second.

Even if one is FAST, it takes about a half second to realize what is happening,
and another half second to figure out what to do about it.
By then, you might have gotten too close to avoid a crash.

And, for most of us, the first time it happens, we are just NOT that fast.
Persons not knowing about it at all ... will likely be slower yet.

So, the "fix" that Toyota has been putting in new-manufacture cars for about
a month, is now available to the rest of us.

Thanks, Toyota!
I got it "installed" today.

[adrianblack]

While the SGII is slow to update and might not be hugely useful here, I added 3 new XGAUGEs to my spreadsheet tonight:

- Regen Cooperation: On or Off depending if Regen braking is actually happening or not
- Regen Requested: Shows in NM what the Skid ECU is asking for Regen wise
- Regen Operation: Shows in NM what the Hybrid ECU is actually delivering in regen braking


https://spreadsheets.google.com/ccc?...ZTUR1eVE&hl=en

Could be useful to see if regen really kicks off at the slightest hint of ABS activation, etc etc.

[bwilson4web]

Thanks "adrianblack" for the scangauge hack. I don't have one but it looks to be helpful. But I wanted to sum things up:

• 19 mph - threshold speed for regenerative braking referenced on page BC-49 in the 2010 Maintenance Manual
• 7.9 m/sec (17.67 mph) - entrance speed to speed bump showing problem but requires a wet street for braking pause
• 7.6 m/sec (17.00 mph) - exit from speed bump with brake paused, requires "wet street" condition on Huntsville roads, notoriously slippery
• 700-800 ms. - duration of braking pause 5.32-6.08 meters (17.4-19.9 feet)
• 22 images of street and road conditions
  • http://hiwaay.net/~bzwilson/prius/Prius_bump_010.jpg
  • http://hiwaay.net/~bzwilson/prius/Prius_bump_220.jpg
• SSC-A0B - title of the skid control ECU fix (thanks "john1701a")

Bob Wilson

[dzaky]

[QUOTE=bwilson4web;1057014]I
Now you may remember from physics that:

• integrating acceleration -> velocity + constant
• integrating velocity -> distance + constant

what i know from physics is:
velocity (final) = velocity (initial) + integrating acceleration
distance (final) = distance (initial) + integrating velocity

Regards

[dzaky]

[QUOTE=bwilson4web;1058012]I agree. The $3 version works but is limited in the number of samples and if you start another application, it looks like the data is lost. Still:

Timestamp,AccelX,AccelY,AccelZ
0,0.126785,-0.670151,-0.742599
0.100172,0.144897,-0.633926,-0.742599
0.200286,0.144897,-0.670151,-0.778824
0.300247,0.126785,-0.670151,-0.742599
0.400363,0.126785,-0.688263,-0.742599
0.500524,0.144897,-0.652039,-0.724487
0.600505,0.144897,-0.706375,-0.742599
0.700671,0.126785,-0.670151,-0.688263
0.800808,0.163010,-0.688263,-0.742599
0.90085,0.163010,-0.688263,-0.706375
1.00079,0.144897,-0.706375,-0.760712
. . .

I find information of USB Accelerometer Model X6-2A, the Acceleration data must divided by 1024 (high gain) or 340 (low gain).
And i have plot assuming you set high gain in config.txt file.

regards

[eric1234]

Originally Posted by bwilson4web

One of the best source are Toyota's New Car Features:

• BRAKE CONTROL / DYNAMIC CONTROL SYSTEMS: BRAKE CONTROL SYSTEM: DETAILS (2010 Prius), Doc ID: RM000004221000X
• BRAKE CONTROL / DYNAMIC CONTROL SYSTEMS: BRAKE CONTROL SYSTEM: GENERAL (2010 Prius), Doc ID: RM00000421Y000X

This is just a brief summary of the details.

Hi - Are these documents :"New Car Features" publicly available? I've done a Google search, and the only result is this very thread. :-)

I think they'd be interesting to review.

Thanks,
Eric