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Idea for Cruise Control Autopilot Mode

Discussion in 'Model S: Driving Dynamics' started by ToddRLockwood, May 25, 2013.

  1. ToddRLockwood

    ToddRLockwood Active Member

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    #1 ToddRLockwood, May 25, 2013
    Last edited: May 26, 2013
    I'm finding Projected Range to be of questionable value on our hilly New England interstates. The fundamental problem is that the system looks backwards to make its calculation in Average mode, and it varies wildly in Instant mode. The previous 5 to 30 miles may have nothing to do with what's ahead. What's needed is a system that limits energy output (perhaps via cruise control) by constantly comparing the Nav's miles-to-destination to the Rated Range, and using the delta of these two numbers to slow the car down when necessary. A user-selected safety margin (say 20 to 50 miles) would be automatically maintained. This self-correcting system would adjust for environmental and geographic factors as they occur. I'm already using this method manually. Imagine how cool it would be if the cruise control had an autopilot mode to do this for you.


    ADDENDUM

    The only missing piece is knowing, at the beginning of a trip, what your initial cruising speed should be. The drive from Boston to Burlington VT (225 miles) is relatively flat for the first hour, but if you drive too fast on that first section, the car might slow down too much toward the end of the trip in order to maintain the safety margin. Perhaps this is where Google's creativity can come into play — determining average energy usage for a particular route by taking elevation, temperature and other data into account prior to setting off.
     
  2. brianman

    brianman Burrito Founder

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    I still just want a cruise control flexibility knob that I can move from the current value of 1mph to something wider like 10mph.
     
  3. Todd Burch

    Todd Burch Electron Pilot

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    Todd, I was thinking the exact same thing, although you took the idea a step further than me. In the case where someone just wants to drive efficiently (not using nav), i'd like to just set a constant energy output. There have to be limits though. For instance, a "do not exceed" speed for those downhill stretches when matching an energy output would require accelerating to dangerous speeds.
     
  4. stevezzzz

    stevezzzz R;SigS;P85D;SigX

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    You can be sure this functionality (a look-ahead trip planning system, at least) is in the works for a future software release. That's been confirmed but I don't recall where, or by whom. And it will be very welcome, indeed.
     
  5. SCW-Greg

    SCW-Greg Active Member

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    I see geo aware route planning on the horizon, built in to the nav calculations. One that understands terrain and traffic ahead. Longer term, it could also factor weather in.
     
  6. Cattledog

    Cattledog Active Member

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    SCW-Greg - I think that's it, nav linked to battery/motor. You set destination, parameters (speed bracket, desired remaining range, route), the car looks up traffic/weather/elevation/SC locations/etc., voila. Sounds close to a driverless car - I guess we can still steer.
     
  7. brianman

    brianman Burrito Founder

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    Almost what I'd want. I wouldn't want a constant energy output, I'd want to set an upper bound. Let's take an example, suppose the speed limit is 60 and I'm not "in a hurry" but I want to move with traffic (~ +5 relative to speed limit) mostly.

    Some inputs to CC algorithm:
    • Yes or No (depends on the trip I'm taking) - Significantly limit speed and consumption to ensure that I reach my nav-indicated destination without requiring use of "reserve" (below "0").
    • Yes or No (depends on mood, weather, etc.) - Automatically engage range mode for climate control if necessary.
    • 70: Maximum speed - Use regen (then friction if necessary) to avoid surpassing this speed. (In a settings page this would probably be better as a relative delta to the ideal speed, so "+5" in that case.)
    • 50: Minimum speed - Use acceleration up to my specified limit to maintain at least this speed to avoid being a hazard to other traffic. (In a settings page this would probably be better as a relative delta to the ideal speed, so "-15" in that case.)
    • 65: Ideal speed - Aim to reach this speed when other constraints allow, but don't go crazy trying to keep it between 64.5 and 65.5 mph. This is the only input that is currently provided, via the stalk.
    • 240 kW: Maximum consumption - Even if you have to briefly go below the minimum speed, don't consume more than this.
    • Flat, Hilly, Mountainous - Rough description of the terrain on my route. This is a SWAG from the user. With a nav route engaged, the Model S could be "clever" with 3G providing elevation information and (some other service) providing weather and traffic.

    Give me a page in settings where I can provide clear inputs like this or "I don't know" (for Flat/Hilly/Mountainous for example), and then implement an algorithm around it. Introduce it as "Clever Cruise Control" (or whatever you like) and refine it thoughout the firmware iterations based on customer feedback. Except for the last bullet, none of these are algorithmically complicated; granted things get harder when you translate to code sometimes, but "it's not rocket science". ;)
     
  8. ToddRLockwood

    ToddRLockwood Active Member

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    Some good ideas here!

    I've added an addendum to my original post, above.
     
  9. dsm363

    dsm363 Roadster + Sig Model S

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    Would a opt-in Waze type system work where drivers would send anonymous data that only includes route, temperature, speed and other useful factors? This might give more accurate data for trip predictions as well.
     
  10. ToddRLockwood

    ToddRLockwood Active Member

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    Way cool idea!
     

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