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Charting speed and acceleration vs. time (dashcam data)

Discussion in 'Model S: Driving Dynamics' started by brianman, May 7, 2013.

  1. brianman

    brianman Burrito Founder

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    I'm having trouble wrangling Excel to do what I want but I figured folks might be interested.

    In roughly an hour's worth of data samples with a few hours of writing the tooling to extract the data from the files and about 20 minutes wrangling the numbers in Excel:

    SpeedAccelerationChart1.png

    There's a bit of "data overload" here so the acceleration part of the chart leaves much to be desired. I'll have to look into filtering the data a bit more.


    If anybody on the forum has experience massaging such data, I'm listening. :)
     
  2. brianman

    brianman Burrito Founder

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    So I had a few bugs in my tooling (that are now fixed) and picked a better (and shorter) sample period.

    SpeedAccelerationChart2.png
     
  3. CapitalistOppressor

    CapitalistOppressor Active Member

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    Nice. What are you using the capture the data?
     
  4. brianman

    brianman Burrito Founder

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    The speed is from the GPS data file and the accelerometer data is from the 3GF file. It's good to see them sync'd up with each other.

    • 18:37:10 : stop light
    • 18:37:26 : let off (including regen) to let a threatened BMW floor it and get past a lane obstruction
    • 18:38:31 : right turn at stop light
    • 18:39:07 : let off the accelerator to keep a safe distance from the decelerating BMW (and road veers to the right)

    This data lines up correctly with the video footage (MP4). :)

    Interesting sidenote: The deceleration concluding at 18:37:10 was triggered as a "high deceleration event (potentially collision)" (I was surprised the light stayed red). Yes, the Model S has good brakes.

    - - - Updated - - -

    Same one as Dr Taras.
    http://www.teslamotorsclub.com/showthread.php/14877-Al-amp-Ed-s-Dr-Taras-Model-S-gets-customized!?p=328406&viewfull=1#post328406

    - - - Updated - - -

    Peak acceleration in the direction of travel was 42 units (0.328G) and maximum deceleration was 112 units (0.875G).

    I definitely wasn't hammering the brakes, just moderate pressure coupled with regen.

    Random data point from the intertubes in March 2005:
    Braking g's Comparison (edit 6/23/05, 14 additions) [Archive] - AudiWorld Forums
     
  5. Zextraterrestrial

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    Humboldt/Los Altos

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