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  1. #1

    Hybrid Human Interface (HHI)

    The present offerings in Hybrid cars have one obvious omission, there is no way to directly control electric assist or charging. You always have to press down on the throttle, use more gas, and then when the engine load, and resultant reduction in MPG reach some factory predetermined point the electric drive kicks in and adds power. Same with the charging. We are only being offered one option, gasoline priority, automatic hybrid activation.
    The mix of gas to electric is not adjustable.
    What if you could adjust the activation points, or even better activate the electric assist at will without any changes to the throttle?
    You come to a small hill, and just add a little electric assist,to top the hill with no change to the throttle. To recover the used energy, you charge aggressively on the down side to recover the energy, and to control the vehicle speed without the need to use the brakes.
    The resultant system will surely improve on the rather crude control systems that are now being offered. How can the computer see the hill or stop light ahead, and use the available hybrid drive more efficiently than a skilled driver.
    The control system would need to be able to see ahead, by tying into an on board GPS system with topographical look ahead feature which to my knowledge is not available.
    After some experimenting, and lots of hard work, I have managed to design and build a manual electric controller for my Honda Insight. The idea made a lot of sense to many other Insight owners, and now there are eight systems in daily use. The system is called MIMA for Manual Integrated Motor Assist, and it offers a programmable mode that allows assist and charge set points to be set, and adjusted while driving.
    The system has only been in the hands of the first users for a short time but so far it is showing improvements in efficiency and also performance.
    We can buy cars with automatic or manual transmissions, why not automatic and manual operational modes on all hybrids to better use the powerful computer in our heads to learn how to best control the Hybrid systems.
    More info is available at:
    Be sure to follow the link at the bottom of the page for the full MIMA info.
    Discussion by MIMA users:
    Mike Dabrowski

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  3. #2

    Hybrid Human Interface (HHI)

    does anyone know if the mima isavailable for the honda civic?, this almost sounds too good to be true.

  4. #3

    Hybrid Human Interface (HHI)

    It is true. A human can "drive" the Hybrid better than a computer can.
    The proof is in the reactions and experiences of the people now using the system.
    Unfortunately the HCH has a different control system, and the MIMA system as designed right now can not work with the Civics.
    It will work with the CVT Insights though.
    My hope is that we will get enough of the systems out there that the Hybrid car makers will adopt a similar control strategy based on the MPG improvements that users are having. MIMA Insights should dominate next years Tour de sol in the Insight division. Some recent post from MIMA users indicate that high MPG numbers can be achieved at higher speeds than without. One Hyper miler with MIMA drove from SC to DC (over 500 miles), and got 104.3 mpg for the trip.

  5. #4

    Hybrid Human Interface (HHI)

    why not add a simple proprioception circuit to the system whereby the system could sense going up hill due to the change in a glob of mercury rolling inside of a horseshoe shaped sealed tube (ends facing up) with a linear pot inside. While on the level, the system would operate in std fashion, as the car angles up to climb a hill, the mercury would slide to the rear facing horn of the tube changing the voltage to - say - positive - meaning lay on the juice - we're going up a hill...then, when going down a hill the mercury would slide over the the front facing horn of the tube and turn on the regen braking. Of course you'd need a damping algorithm/activiation delay to prevent bucking loops when the car gets jostled over railroad tracks etc.

    On could find simple forms of this pot inside old HVAC thermostats to do a quick "giggle/smoke test"


  6. #5

    Hybrid Human Interface (HHI)

    I looked into tilt sensors, and found several that could detect the small tilt change, they are not cheap, and would have issues with detecting pure tilt from acceleration. After driving with the MAP based PIMA system, I found that the driver can make a better decision as to the best time to apply assist, simply by pressing down a little more on the throttle. The key advantage to the system is the ability to set the assist activation point at much higher MPG than the stock system, and have the assist become stronger much faster than the stock system. I typically set the assist point at 95MPG, and full 100Amps of assist will be engaged by the time that the MPG is at 80MPG. The charge setpoint is set at 115MPG, and the full 50Amps of charge is engaged by the time that the MPG is at 150.
    I tend to keep my throttle so that the MPG is between the setpoints, so no assist or charge is active on flay ground. When climbing a hill, just a slight increase in throttle gives me just the right amount of assist to make the hill with minimal loss of speed, then I decrease the throttle and control speed by the amount of charging I allow. When the two setpoints are balanced properly, the battery charge stays at 50% or better.
    It works quite well for such a simple control scheme.

  7. #6

    Hybrid Human Interface (HHI)

    I must observe that the "computer in our heads" would not be a workable solution for most drivers. I believe the Prius design, largely "drive by wire," does a substantially better job of managing available power that the vast majority of drivers could. Even with my "more than average" computer knowledge (mostly software), I am happy to allow the onboard computers manage power and battery condition.

  8. #7

    Hybrid Human Interface (HHI)

    Hi Mike - thanks for the reply. It's a rare breed that wants to have another thing to control.

    Of course you know that it'd be simple to test (if tilt AND speed decreasing THEN etc)...

    the typical buyer wants the minimum to take care of. You are aiming at early adopters so I understand. Just trying to help out.

  9. #8

    Hybrid Human Interface (HHI)

    I guess the hard thing to imagine about PIMA (programmable IMA), is that once set, you just drive like before, giving it a little more gas as you reach the hills, which with PIMA gives lots of assist to allow the gas engine to work less for the hill climb, and on the down hills, just let up on the gas a little, and regen begins to engage to charge you back up. The driver involvement is to try and maintain speed, or allow a slight drop in speed up the hill so you don't drain the battery more than necessary. Quite intuitive after a few minutes.
    Since it is all programmable, the assist leveland activation point, and regen level and activation point can be easily adjusted to compensate for terrain changes.
    If you tried it, you will probably like it.

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