MIMA introduction


The path into the future

What is MIMA what does it mean in MPG to change the hybrid mix to predominantly electric. If all the cars on the road today were to be converted to electric tomorrow, the batterys would take 20 years to make, with production of some of the rare raw materials being the limiting factor. Hybrids will be the transition automobile to a future of light weight commuter cars that are fast safe and super efficient, powered completely by home solar recharging.

All production Hybrids computer controll the mix of gas to electric, so they are Automatic hybrids.
We have to break the mold, and rethink the way we build cars. MIMA is a step in that direction. MIMA allows the driver to be the boss, a true Manual Hybrid.

Since the beginning of regular automobile use, the automakers have settled into a fairly universal way for us to operate the car. 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 automatic transmission was the first time that we gave up one of the controls, and let the car do it "automatically", even if the result was less mileage. We still have the choice to buy a manual transmission, but are gradually going to find that the automakers want to make only one transmission, and it will be automatic, so our choice may soon to be taken away.

In 2000, the Honda Insight Hybrid and then the Toyota Prius Hybrid cars became available, and to my dismay, there was no driver control for this second "free" source of power. 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.
Some may correctly argue that many drivers could not come close to understanding how to mix the gas and electric, and are better off with the car doing it's thing.
I am not talking about those people, I am talking about the people with good driving and awareness skills that can and do learn how to use the available controls to best advantage.

What ever the automakers reasons were, (I am sure there were many) they chose not to offer us an opportunity to control this very important ratio manually.
A new control system was forced onto us, the automatic hybrid .
The electric to gas ratio on todays hybrids are controlled by supposedly smart computer controls.
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.
Is it smart to charge the batteries while going up hill? My stock Insight does that.
Is it smart to force me to drop from 100 mpg down to 50 before I get any electric assist to top the small hill I am on? These and many other quirks of the control system in the car are begging for a fix.

I created MIMA to give us a shot at making the Insight better, by creating a Manual Integrated Motor Assist
With MIMA, and the Honda Insight, we may have our only shot at experiencing this level of manual user control of the hybrid mix, 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.
If the automakers were to give us an option, a direct connection into the main control system of the car, for those wanting to make the car better. A PC interface complete with control language specifications.
This PC interface would allow the millions of highly trained hardware and software engineers that drive their car to work and back each day, all over the world, to tune the car to his particular commute and driving style.
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 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.