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Ultimate Mod? Reverse Engineering

Discussion in 'Gen 2 Prius Accessories & Modifications' started by Popeye, Dec 14, 2005.

  1. Popeye

    Popeye New Member

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    So I've been lurking here for a long time, taking lots of good ideas away and using them to increase my MPG and driving enjoyment. Here's my beef with my Pri - I live at the top of a hill, drive about 2 miles flat at speeds above EV mode speed, then lose about 1200 feet of elevation pretty quickly. I use a bunch of different methods to try and drop my battery charge before I hit the hill, but almost always end up with solid green before I'm more than 1/3 of the way down. So, even if there is another 20% of battery capacity available, I'm wasting some (or even a lot) of my hill.

    Seems to me, with navigation installed, that the Pri should be able to store an "energy profile" for regular trips (if the map was 3D wouldn't even need to be a regular trip). I'm envisioning a system where you could drive a route (say the normal commute or the trip to the grocery store) and tell the nav system to store the route and information about energy usage. On later trips you could "tell" the Pri what route you plan to take and, rather than making semi-intelligent guesses, the car would "know" what the energy profile for the trip looked like, when "free" energy would be available, etc.

    I do a lot of machine programming work, the above wouldn't be too hard to add to a decent industrial computer (which is basically what the Pri uses), but I've never tried to reverse engineer the car's computer to figure out if the programming could be done by users. Also haven't seen much on that topic here or elsewhere.

    Any thoughts? Any experience with modifying the Pri's programming?


    -toss the ball up in the air and see what happens, open source collaboration-
     
  2. efusco

    efusco Moderator Emeritus
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    Yup, this has been patented by Toyota and is, presumably, in the works for the next generation Prius.

    See: http://privatenrg.com/#terrainfollowing
    You'll need to scroll down until you get to the section titled SOC pre-staged for upcoming Terrain
     
  3. WeMustEvolve

    WeMustEvolve New Member

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    Wow! What a great idea. I'm supprised that this would be in the works. Another example of GM and FORD loosing out. :(
     
  4. hdrygas

    hdrygas New Member

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    The only thing I would add is that there are limits to this. Part of the systems job is to protect the battery from over or under discharging to increase battery life. You would see some improvement. I wonder if using the CAN View to better discharge during the 2 miles up to the hill. Knowing the discharge rate might let you optimize discharge even if the ICE is running.
     
  5. slortz

    slortz New Member

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    Are you sure that Toyota has patented this? It looks like the SOC pre-stagging by terrain stuff is a private venture thing based on what the guy writes after the explanation.
    I think it's great either way but would be better if Toyota does patent it that way upcoming Prii will have it integrated from the factory and people won't have to worry about voiding their warranties by adding on an aftermarket part.
     
  6. efusco

    efusco Moderator Emeritus
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    I'm about 90% certain that Toyota patented the terrain mapping.
     
  7. hobbit

    hobbit Senior Member

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    I played with this a bit while tooling over the mountains along
    the Blue Ridge in december. By deliberately emptying the battery
    more near the top on the way up [by pushing harder or EVing], I
    definitely had more room to collect energy on the way down before
    it was all just brakes and "B". But for any of this to be worthwhile
    you need fairly serious hills -- otherwise there just isn't
    enough energy in the car's height to matter that much.
    .
    _H*