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OK, let’s have a MIMA thread, wherein, the users can share their tips, tricks, and techniques.

I should note here that I run in MIMA and not PIMA, and as those MIMA users that also have the FAS mod already know, FAS won’t work in PIMA. So, you have to be in MIMA to do what I’m going to explain.

I have come across a particular set of circumstances, in which I have found a technique that seems to be helping the FE.

After a long FAS, to a 90 degree nonstop turn/corner, speed dropping below 20 mph, I will shift into 2ND, accelerate slightly, then 3RD, more gentle acceleration, then into 5TH at ~30 mph, and try to get into LB for the final stages of acceleration up to my target speed of 35mph, since I’m in that speed (35) limited zone.

Those who have watched OBD while monitoring the O2 sensor voltage, in real time, have seen that after one of these long FAS maneuvers, the O2 sensor goes through its “freshman orientation” all over again, just like a cold start. Perhaps it, or the cat, cools off enough during the long FAS, that the ECM starts all over. It is very reluctant to give you LB, until it “finds itself again”. It takes it’s jolly time getting there. I want LB, and I want it NOW.:Banane36:

So after turning the corner, and upon finding 5TH gear, I will gently push forward (assist) on the joystick. No more than 1 amber led (4 on the factory display), while at the same time, letting up gently on the accelerator; just like you would normally do to get into LB. I let the iFCD bounce off of 150, then ease back down to around 125/130 to verify that it has given me LB. The result is; the target speed is reached because of the nudge from MIMA, and the best part; it is into LB.

It might give LB just as easily by letting up on the accelerator, far enough to see the iFCD hit 150, but there are some side effects of doing it that way. If you let up completely, you will see FC (fuel cut) mode, (I have an indicator for that), or; depending on where your ABC (Adjustable Background Charging) is set, you will see some level of regen kick in. Both of these cause a decrease in acceleration. I don’t want to slow down, I want to cruise steady-like. I want to do it in LB. This technique seems to be working. Have any of the rest of you experienced something similar?

Randall

I also have found a small nudge from MIMA 1~2 Bars can help get into lean burn allot of times....

I have not noticed the long FAS effects you mention... I rarely have a good opertunity for long FAS.... And recently I have been wondering about the difference between shifting to neutral and using MIMA to get regen to charge the Battery while coasting instead of FAS.... A Warmed up Insight ideling in neutral during a coast burns very little gas... MPG will be way above 150MPG point.... and the 10~12Amps or so of regen I can get from an Idel MIMA Regen can be nice for restoreing a low charge on the pack.... But if I am 3/4 of a charge or more I prefer FAS as there is less benefit to regen the higher the SOC and the benefits from less Fuel use are nearly constant.... I know I prefer to use the MIMA Idel Regen instead of FAS if the ICE is still cold and not warmed up yet at a stop.... but that is usually only the very first stops as the ICE warms up pretty quick.

Where do you connect to the ICE for your Fuel Cut lndicator??? I know there is a relay marked as fuel cut in the service manual but was wondering if it is the same place you use.

Also I have noticed that the Self Discharge of the Pack can often trigger a recall for me if I park the Car for a week or 2 without running it.... So I will often times push my car the last bits of the way in MIMA-EV Fuel-Cut mode so the SOC is around ~50% or so when I park it... It doesn't seems to recall hardly ever if I use the car daily... but allot of times a bike ride to places works fine and uses less than even the Insight.

Hi Guys
Great idea for another MIMA thread.
The health of ones battery pack will to some extent effect how one would use MIMA, as well as the terrain and speed one needs to be running at.
Randall's pack is suffering from recals 3-4 bars from full, so he is going to use MIMA a bit differently than I would with full pack capacity.
FAS use will also be dependant on the capacity, as one will tend to choose regen over FAS if the pack needs charging. A tricky balance, and some tough choices.

I am in new territory with my system since I can recharge with the booster, and only need to make sure that I don't use the charge faster than it can be replaced, so I tend to use PIMA set to 110-120MPG initial activation, with a mag factor of 3. I can maintain speed at 55-65 MPH for as long as the boost system has remaining charge.

I think a discussion of the FAS verses regen decision on down hills from different peoples perspective would be very useful, as it is the toughest decision to make.
JoeS, Calpod, and a few of the other guys have a lot of experience with both, what do you think?

Hello Ian.....man I can hardly keep up with you guys on that battery talk you got goin'on.

For the fuel cut indicator, I tapped into the signal going to the fuel pump, at C501.This connector is just to the left of the ECM under the passengers floor carpet. ETM page 23-11, photo 69, view 153, 16 pins, pin 2 is fuel supply system, BLK/YEL wire.

I feed this signal thru a 22k resistor to the base of a 2N3906 PNP transistor. Between the base and the emitter, I placed a 220k resistor, then connected the 12v (IGN-on) power to the emitter. The led indicator and suitable resistor is connected between the collector and body ground. This is what I have scratched in my manual anyway. Without a doubt, you could better engineer the components, and I’m sure there are other values of resistors that will work. This layout has been working for sometime now in my Insight.

I have included this fuel cut indicator, in my useless coin pocket mod, which I will also do a thread on shortly.

Randall

Hi Randall,

I don't yet have the "safe" FAS mod, so it was interesting to hear your observations about the O2 sensor and the reluctance to re-enter lean burn after an FAS.

Since with my new commute (only about once a week now in the Insight when the weather is favorable to the bicycle) I live mostly in the 30 - 35mph speed range, I've been using a technique as you've described to maintain LB. It does work very well for me. Unfortunately, I have over 15 stops in a 10 mile distance, and that messes up the FE big-time. The big hills don't help the FE either.

Based on your amazing tank record (in progress or soon to be completed??) we're very interested in hearing about your MIMA techniques.

-Brian

Hey there Brian,

Ouch......15 stops!!!!

That short a distance and hills to boot, sounds like a good application for Mikes plug in booster pack. Charge it up at night, dish it out with MIMA during the uphills. Course if you had a good factory pack..............but I know how that goes!

Yes, I will expound a little on my MIMA usage, shortly.

Randall

One aspect of MIMA that has not been discussed much, but is pretty important is syncronizing the application of assist with the throttle. Pima takes care of this, but manual joystick operation will allow you to let up the gas, while adding assist, which robs a lot of the assist energy just to keep the ICE at rpm, let alone to speed up.
I have found that in first through 3rd gear especially, it is easy to waste a lot of assist if one is not mindful of this.
Example:
You are in second gear going about 2500 rpm. the gas engine is not pulling, and is at 100MPG.
If you give a lot of assist, the effect of the assist will try to rev the gas engine, but will have to back drive the gas engine as it is happy at the 2500 rpm. Step down just a bit on the gas so the engine is trying to accelerate and rev more, and give the same assist, and you will get a lot nicer boost from the same assist.
The higher the gear the easier it is to add assist without the gas engine fighting, so I tend to be in 5th when over 30-35 MPH for that reason.
I find my self stepping down to just begin to drop from the 150MPG point so I have a light load on the ICE, then I add assist.
I am sure that all of the MIMA guys have found this but figured it was worth a mention.;)

Some preliminary results from Paul Andrews in the UK, indicate that his racing Insight CVT has better performance using PIMA than without:
>> Hi Mike,
>> > > did first test with MIMA yesterday.
>> > >
>> > > Interesting results. We were doing 2 way acceleration runs on a 0.8 mile
>> > > straight at Millbrook. These results are from the speedo as we have not
yet
>> > > analysed the logged data, with the car running E85 bio ethanol.
>> > >
>> > > IMA off terminal speed 93
>> > > IMA on 97
>> > > PIMA on 101
>> > >
>> > > We later did a run on Standard 95 unleaded and recorded 104 with PIMA.
>> > >
>> > > We have not yet done any mods to optimise E85 performance.

The car is heavily instrumented, and we can expect lots more comparison data.

Have not asked him what his MPG is.;)
A short article about Paul's efforts:
http://www.green-car-guide.com/news/lowest-mot-emissions-from-rally-car.htm

Hi Mike:

___Now this is a great story about pushing your technology advances and is really neat to hear about it in the real world.

___Good Luck

___Wayne

More info about Pauls efforts:
http://www.**************.net/forum/viewtopic.php?t=5636
;)
Paul's two Insights will be another battery pack test case, to see how packs like heavy assist and regen.

Hi Mike:

___Sorry about your link. About 4 – 5 months ago, Insightful Trekker and Benjamin placed CleanMPG in their dirty word filter. About 2 months ago after some more harassment, we had to reciprocate.

___Good Luck

___Wayne

If you respond the same way they do, things will never improve. The best way to combat overmoderation IMHO would be to ignore it, rather than doingit back to them, but it is of course your call.

Mike, normally I would agree with you. But we gave them slack for so long and all they did was get worse. I think it is unfair for them to actually put our site name in the dirty word list. I can see them not allowing links back to the site and stuff like that. But to actually not allow our site to get talked about is to me a far cry from just over moderation.

We didn't do the censorship out of revenge (much). Mostly it was to show how ridiculous what they are doing is. I don't know if there was any outcry over there to remove us from the dirty word list other than from some of the regulars over here.

I will probably remove it eventually from our list. If there is an outcry from the membership here I will certainly listen.

One thing though is that they should worry about ticking off other websites because starting now I only see their membership dropping as insights are no longer being produced.

I wish they would be a nicer website, but I'd much rather them come here asking us to remove them from our list if they really want it removed. I bet they don't even care.


We should probably bring this thread back on topic. If you want to discuss it further you could start a thread in the website news and discussion forum.

New MIMA users first report:
http://www.99mpg.com/people/andylamm/
Another happy MIMA user.

I am curious, How many MIMA users use PIMA regularly?

I am thinking of doing a few small changes to the FAS relay activation system. I find that I have to hold my FAS sw longer than I like while the engine decides to finally die, and would like to have the system hold the relay closed until it detects that the map signal shows a stalled engine, then release, so the safeties can still restart. That way if the central sw is pressed and held for 1-2 sec, the MIMA system will take care on holding the relay till the engine really stops.
Are there any software issues that you guys would like to tweak, add, or change, while I am in the code?;)

Hi Mike,

Sorry for not responding sooner. I still use a mixture of all 3 modes of control, that being factory, MIMA, and PIMA; but MIMA is by far where I stay most of the time

The MIMA holding of the relay until the rpm's have dropped would be a cool addition to the code.

Randall

Randall,
Thanks for the feedback, I don't know how many of the MIMA guys are watching this thread, so I will take that as a confirmation of my plan.
How long of a hold of the central sw would you think would be long enough to assure that it was not just a bumped joystick, rather than a true FAS request? I am figuring 2 seconds should be enough, or do we want a double click?

Some bad news on my car.
I have been noticing that I can't seem to get as much speed when using the E-wheel, and my un modified MPG has been suffering, more than the cold weather would account for. The brakes are freed up, so that was not it, but discovered that my rear tires are wearing on the edges.
After doing some front to rear eyeballing, it looks like the 400 lbs is begining to have it's toll. Both rear wheels are bent outwards on the bottom. I think that some of those bigger pot holes may have twisted the rear axles up.
Bummer.
I will have to start tracking down a new rear torsion arm. Anyone know where I can get one?
The 5th wheel is hanging in there, but has developed a squeak between the aluminum covers, that a file should fix.
Still getting my heating system fixed, so the car will have to wait.
Too much to do, and not enough time to do it.
;)

hey mike:
is it possible (or already in place???) to have different ramp rates for regen and assist in pima mode? i like instant assist, but the instant heavy regen makes the car jerk a lot while shifting. sometimes kills the engine entirely.

HAFNHAF,
The mag factor is the assist ramp. The regen is always equal to a Mag of 1.
The way it works, the setpoint to actual MAP signal diference is either used without modification (Mag 1) to generate the MIMA control signal amplitude, or it is multiplied by 2,4,or 8. The regen difference is always used without modification, so it is always MAG 1, or the most gradual ramp. I found that a quick shift, will work best, to avoid a regen blip.
If you think it regens fast now, you should have seen it when the regen mag factor was the same as the assist.

ok, i didnt realize the regen ramp rate was stock. so i guess backing off on the assist ramp (mag factor) wont change the way regen gets applied. oh well.

i went back to the assist magnify chart on 99mpg and saw (finally!) that the regen part of the diagram only shows the possibility of a setpoint change, while the assist portion shows both setpoint AND ramp rate change is possible. now i get it!

thanx!!!

The graph is pretty good once you get what it means.
Since I can change the program easily, I could modify it to give you 1/2 mag for regen, where the difference between setpoint and MAP would be /2 before converting to the PWM regen signal.
If you feel it is something you want to try, let me know, and when I am back in the code, I can make you a custom version with that feature.
Do I have your spare chip/ or do you have it?

i have not upgraded the s/w since i built the kit. i think i have 1.05? i remember something about triggering the brake lights above some number of regen amps??? i dont have that version. or maybe that was just an idea you were kicking around. that would be cool to run to my "VHMBL" (very-high-mounted-brake-light.) and keep the stock brake lights for the brake pedal. might be kinda confusing to whoever is behind me, but might just get their attention as i use max regen to slow down at times.

in terms of who has the chip, i guess you do, since all i have ever had is the one in the board.

Andy
I looked up your system. You have software version 1.5.0
Since then I have added several things, as outlined below. Your code has the code for external brake light activation over 15A. That would be AR1, the violet wire. AR1 and AR2 are open collector transistors, and the brake lights are high side switched, so a relay needs to be used to properly drive them, as shown on the harness PDF. Calpod was going to use the AR1 output to illuminate a sign that said "RECHARGING", to keep people off his tail.

1.5.1 Change the display brightness to the set value after brightness cal step in calibration, was only correct on exit of cal mode before.
Cosmetic change

; in BG charge, display make the XOXOOXOX pattern appear if the BG charge value is at min (0 amps) or max (25 A)
Helpfull to know when you are at the limits


;fix reversed detection of Assist at stop function to properly turn off assist at stop if option 1 is in the default condition
Bug, only effects system when you want assist to operate when stopped

;1.5.2 Add config bit 3. "halfassist". When set, The full joystick range will represent ony 50% assist rather than 100%
Was included for the guys having recal issues, that do not want the assist to get over 50%


;open up center dead band for CMDpwr so side jogs don;t activate by accident.
Helpfull and makes jogging more reliable.

;1.5.3 Fix the no mode1 led when in MIMA on demandbug caused by the last code.
Bug fix

;1.5.4 make AR1 control the boost charge or activate on >15A regen, using option 4 to toggle from default(boost enable) to alternate (brake light >15A)
Allows configuration of AR1 output from brake light to controll for my boost system.

;1.5.5 invert the boost enable function
Bug fix.
I have your extra transport chip, and can send you the latest code if you would like.

Mike,

I have been thinking about the Brake light, do you think it would be possible to "piggiback" another set of LED's similar to the one's we have now for the display, except, this would mount in the headliner, and it would face the rear of the car, so when you are in traffic, you could just turn a switch on and the LED's would light up together with the display.

This would give you another display so that the driver behind you would be able to see the same lights you see on the display, I think you would not want to display assist, only Regen.

I notice when I'm in heavy traffic, I don't use the brake at all (most of the time) but some drivers will tailgate thinking I'm not using the brakes, this would give them a hint that you are slowing down, as well as showing them you are charging.

We would just need another connector and some extra wiring. do you have any we can buy from you? I have the extra display.

Thats a good idea.

Calpod,
As Tom said, that is a good idea, Lets see what it would take.

The output drive for each led comes direcly from the Micro, and uses the 5V MIMA power supply.
The display with max brightness on all LEDS, and the MIMA board with the two relays on will draw nearly 250 MA. The fuse on the board is 250 MA. Drawing further current from the Micro board would cause the fuse to blow.

The PWM brightness control transistor is driven through a 1K resistor on the MIMA board (R30).
To drive two of the PWM transistors, we would need to short R30 on the board, and add a 1K on each of the display boards, but this would still use the MIMA regulated supply for the current, and exceed the limit of the fuse.


An auxilary "Brake" light was to be driven from 12V, and use AR1 power transistor to complete the path to ground, so that current would not use the MIMA regulated supply.

If you only want the regen leds, it would be better to just breadboard the 4 leds and add 4 driver transistors. For a rear facing display, brightness could be set to max.

Original charge light schematic. The color, and number of Leds will determine the value of the series resistor on each led string.
http://www.99mpg.com/Data/downloads/relateddocuments/calpodschargingdisplay.pdf
Recomended regen repeater schematic:
http://www.99mpg.com/Data/downloads/relateddocuments/calpod_rear_regen_repeater.pdf
I do not have the necessary connector to add a second tap off of the main display cable, but could get some if you wante to give this a try.
;)

Mike:

sorry I didn't get back to you more quickly. Been crazy busy at work. as far as the updated chip, sure, send one out when you get a chance. absolutly no rush, i know how busy you are. just like me!

andy g!

Hi Mike,

I'd like to see an option to choose when AR1 activates at >15A regen: All the time, or only when in MIMA/PIMA. That way a relay on AR1 can be put in parallel to the stock brake pedal switch, but won't activate full regen when in standard IMA mode.

BTW: Howdy Clean MPG! Long time listener, first time caller. Recent IC voluntary expatriate. ;)

Welcome #20.

Randall

Welcome indeed Fenrir
OK we have two proposed software changes,
1. FAS using AR2 would upon initial one second hold of central sw, keep AR2 activated until the MAP signal shows actual engine stop, then it would release AR2 so automatic restart for all safety conditions could restart. As a safety, if the engine does not stop in 10 seconds, release the FAS relay.
Any other precautions for FAS?

2. AR1 would activate upon regen of > 15A, only when MIMA active or PIMA was the active mode. I am leaning towards having this be the only operational mode for the brake function.

AR1 would still be able to be configured for boost enable instead of brake light activation.

Any other things we want to include or change?

MIMA and P&G
I drove down I 84 today to Hartford. I was traveling at 60-75 MPH.
Anyone that has driven that route will attest to the huge hills.
I did not have the boost system turned on as I wanted to have a full charge on the booster batteries for my demo at Trinity college.
The hills presented a great chance to use MIMA and P&G together. My version of P&G is to climb the hill while loosing only as much speed as the prevailing traffic allows, with MIMA providing moderate assist. On the down hill, I do FAS, letting the speed raise as much as the traffic allows. I do the regen as a light ABC (Automatic Background Charge) while running on level ground. The average speed for the highway was 67 MPH, and I got 77 MPG.
The gains provided by engine off coasting, more than balanced the slight MPG hit with ABC doing the gradual regen. When I would loose too much charge, I would keep the MPG at 100-110 MPG on the down hill, while getting full MIMA regen, which maintained speed but gives full regen.

You have basically described my commmute technique. MIMA up the hills losing just a little speed while maintaining 100 to 125 mpg indicated, and then FAS down the back side, and dribble in the charge with ABC on the flats. Sort of a high speed P&G?


And your proposistions for the new code sound good to me.

Randall

I have been noticing that a frozen IMA battery takes a long time to get above the 40-45 F that is necessary before the IMA responds properly. If we put a switch across the MIMA fan control TIP120, we could turn the battery fan on full once the car is warm, to draw that warm air through the IMA pack to speed up the warmup.
This would also draw the frozen outside air through the Inverter which should not be a problem.

Hi Mike,

This winter is far colder than last winter here in OK. Only my second winter in the Insight.
You know the state of my IMA battery pack.

I have had a recal nearly every morning when leaving work with the IMA battery temp showing single or teenage temps F.
(Although these cold-temp recals are not the deep, totally forgot where I was recals, that take forever to make it back to the top of the factory display, but rather quicker; regen to 5 or 6 bars and then climb to the top at about 1 bar per second.) That is with MIMA in Mode 1.

When I leave it in IMA factory mode, and let the default factory force charging warm the battery, I don't see any recal on these trips, but it takes a long time for the back ground warm-up charge to go away.

I have a couple of 12v PC fans on the vent behind the passenger seat, which I can turn on, and push the warmer cabin air into the IMA cabinet. This helps bring the BAT and MPI temps up quicker. Yes, you are right. It speeds up the warm-up process, even with the dash board climate control set on 61F, the IMA temps will get up to 50ish by the time I get home, some 70 min later. They will get up to 35/40 in a decent time frame.

Your question about the cabin temps, answered here. (http://www.cleanmpg.com/forums/technical/t-engine-compartment-temperature-comparison-3471.html#post20827)

Randall

I tend to leave the IMA system to do the battery warm up, as it uses a sawtooth pulsed warm up charge waveform instead of the steady dc charge like after warmed up. I have not looked at the charge waveform when ABC is charging when the batteries are frozen, but from the MIMA leds, it looks like the charging is steady, which may not be ideal for battery defrosting.
Here is a case where Ford 's battery pack is better managed than Toyota or Hondas, They have an electric heater in the pack.
I will have to put a warm up fan control subroutine in MIMA if I ever get the time to get back into the software.

MIMA regen brake light:
Calpod and several other MIMA guys have asked if the brake lights could be tied into the MIMA board to activate the brake lights when doing regen over 15A.
The problem here is that as soon as the system sees the brake sw activation, the MCM which is watching the brake signal will ask for full regen.
This simple single relay circuit will activate the high mounted brake light bar but not the regular brake lights when MIMA sees over 15A of regen.
I have not tried it, but it should work.
http://www.99mpg.com/mikestips/
The PDF schematic is also available on the downloads page.