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Since the beginning of regular automobile use, the user interface has been evolving. The first cars had no steering wheels, they had control sticks that steered and accelerated the car, then came steering wheels, lights, clutches, brakes, the familiar foot throttle, wipers, and finally the configuration settled down to what we are all so familiar with now, with our only choice of interface being automatic or manual transmissions.

The driver has always been the controller of all aspects of cars operation through the throttle, brake, and steering wheel, but with the advent of the Hybrid auto, that has changed. We were not given the opportunity to chose from a manual Hybrid drive, or an automatic one. Our only choice, the automatic hybrid.

In 2000, the Honda Insight Hybrid and then the Toyota Prius Hybrid cars became available, and to my dismay, the user interface was left the same as with non hybrid cars. Here we had a new opportunity for the superior skills that humans could bring to the control and balancing of the electric gas ratio, for optimum performance in acceleration or efficiency, depending on the need. What ever the automakers reasons were, (I am sure there were many) they chose not to offer us an opportunity to control this ratio manually. A new control system was forced onto us, the automatic HHI . The electric to gas ratio was controlled by supposedly smart algorithms under computer control. Can the computer see the road ahead ? We can. We have a brain that far exceeds the power of the on board microcontroller at making subtle determinations, and we can learn what works best, not fuzzy logic like the insight likely uses. With MIMA, and the Honda Insight, we may have our only shot at experiencing this level of user control of the HHI, as the automakers do not seem to be moving in this direction in their new hybrid offerings, and the communication between modules are moving into a networked serial communication control system which is more difficult to crack, (not impossible).

Through a collaborative effort of the users of MIMA, and the programming skills of many of the users, we hope to show clearly that the human operator needs to be part of the hybrid control system, at least until cars can see and have artificial intelligence. MIMA definable manual and automatic control of the electric drive, should be an option on all hybrid cars.

Gas priority system (Automatic HHI)
With the stock Insight IMA system, one must press down on the gas, lowering the MPG from say 100MPG to 50MPG before the electric drive fully engages to assist in the acceleration or hill climb. You have no choice, as the HHI or Hybrid Human Interface has been strictly defined by the cars software. The batteries may be fully charged, but you cannot use just the electric to get over the hill even small ones.

Electric priority system (Manual HHI)
A careful analysis of the inter-module signals of the Insight has led to a fairly simple modification that allows full manual control of both the charging and assist IMA functions. MIMA can let the driver maintain high mpg, while manually controlling the electric assist to climb a hill with full electric assist, or 14,400 watts (144V X 100A). At this rate The 6.5AH capacity cells can not provide climbing power for long before being depleted. More aggressive assist, means that the charging must be more aggressive as well. With MIMA, the driver becomes part of the battery charge maintenance system, either manually by stopping with the full MIMA recharging of 7200 watts (144V X 50A), or automatically as he lifts the throttle past the charge activation set point. The maximum charge is no more aggressive than if you touched the brakes during an off ramp deceleration, or braking down a hill, and the assist is no stronger than full throttle take offs in first or second. The difference is that we can maintain the full assist or recharging with the MIMA controller.

The forced recharge of the battery in normal IMA mode is limited to 10-12 A of charge when the stock automatic system decides it is time to charge. Once the system decides it is charge time, it will charge continuously even while climbing a gentle hill, and therefore puts a constant load on the engine, when many times it would be better not to. This background load makes maximum MPG difficult or impossible to achieve . With MIMA, the charging can be accomplished at up to 50A of charge, when the situation allows it, at driver discretion, with minimal effect on MPG. Proportional down hill charging allows maintenance of speed without using brakes, during deceleration the aggressive charging can transform more of the kinetic energy into charge before the mechanical brakes are needed for the final stop. When climbing hills the background 10-12A charge can be switched off to maximize MPG. Only time will tell how far the MIMA system will be developed, meanwhile lets enjoy the possibilities.






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