Measurement based driving

WARM-UP




Lessons learned:

• up to 40C - drive modestly, 18 mph or slower, through neighborhood, car will auto stop when stopped, ICE will run to warm-up
• 40C up to 70C - try to keep it light loads, no EGR leaning
• above 70C - EGR leaning occurs, normal driving begins

NORMAL DRIVING





Lessons learned:

• To maximize EGR leaning effects - keep engine speed to 3,000 rpm or less

Bob Wilson

 

Oh, was that the bump in the road? . . . Sorry.

On a serious note, I found trying to drive by visual clues was difficult. But using an audio, reference tone seems to work well for modulating the accelerator. There may be an iPod Touch app. My visual tests suggests that holding the acceleration so the HSI just tickles the far right edge of the red-tip of the display.

I also ran some cruise-control, resume acceleration tests but I haven't analyzed the data, yet.

Bob Wilson

 

It seemed that way at 2:00 AM Wednesday morning. Needless to say, these were informal glances at the HSI display and then to the laptop. I need to improve my recording system.

One lesson learned last night is I need to run an iPod app that generates different tones. With a reference tone, it is a lot easier to hold the accelerator to achieve a constant ICE rpm.

Since my wife's MacBook has a built-in camera, I'll try to take an MPEG showing the HSI display while recording data with the Auto Enginuity. The frame timestamps should correspond so I can more fully map the HSI to what Auto Enginuity can record.

BTW, 'tickling the end of the red bar' does a nice job of gaining speed. If the 3,000 rpm proves out (need better metrics than glances while driving the car,) it also corresponds to a nice inflection point (thanks Hobbit) in the fuel consumption data. But let's get more data before making this a solid claim. <wink>

I still haven't done an energy analysis of last night's data. Mostly I was trying to understand what I'd need to do for a reproducible protocol. Also, I saw some curious behavior on ICE auto-stop.

If I was between 42-46 mph, I would see random ICE rpm -> 0, as others have reported. However, I didn't find coasting down in "D" from 46 to 42 mph would trigger an ICE auto-stop until I reached 42 mph. Then consistently it would auto-stop the ICE at 42 mph. I think there is more going on 42-46 mph than I feel comfortable describing as a control law.

Bob Wilson

 

Not yet. I need to capture the HSI state with a time-stamped, camera while recording the OBD data using the same time line.

My informal, glances suggested the very right edge of red-bar part appears to be closer but just under 3,000 rpm. But I really need multiple, machine recorded values to accurately map any relationship.