Add Another Driving Mode

[JoeS]

Dear Mitsubishi:

I love the ability to modulate regeneration on our iMiEV - in fact, that was one of the major reasons I chose the iMiEV over the Leaf. I find myself constantly moving the shift lever amongst N-D-Eco-B, depending on my needs.

As much as I would like to have a paddle or joystick by the steering wheel which would allow me to modulate regen with my fingertips, I realize this might be considered too radical and that your lawyers may not be willing to allow you to do something this innovative, and thus I would like to suggest that you add another Mode.

Add a new Mode to your shift lever:
I will call it "H" (for Highway), and it would be situated between N and D. It would provide power like D, but would have zero regeneration (i.e., the vehicle would coast when you let off the go-pedal).

Please DO leave the existing D-Eco-B just as they are presently.

When cruising down the highway, I presently find myself constantly alternating between D and N simply because I find it too distracting/difficult to try to position the red needle exactly in the middle between the green and blue zones. I shift into N every time I come to even a slight downhill and yet am still able to maintain a pretty constant speed. Recall, for maximum highway mileage, we DO NOT want to regen unless we have to slow down for some reason.

My 1967 Saab (retired last year, but still in good running order) has this "freewheel" feature, and I found it to significantly enhance the car's mileage. Sure wish my iMiEV had this.

 

[Don]

I think to accomplish what you really want Joe, they would have to add a clutch between the motor and the trans so that 'coasting' isn't hampered by the car turning over the motor. Most conversions keep the ICE 4 or 5 speed trans (and some keep the clutch too) so that slipping into neutral prevents the motor drag from slowing the car. As it is now, I'll bet it would be pretty easy to snip a wire and make D do what you're proposing . . . . make it coast the same as it does in N by disabling regen all together. If you want any regen, slip it into Eco or B. Problem solved without adding an extra 'gear'

Rather than making the mechanical shifter more complicated than it already is, I'd prefer it to have just one forward selection and then toggle the other modes with a paddle - They are all electrically selected anyway and they don't actually 'shift' anything . . . . why try to make them mechanical selections imitating an ICE? I don't understand their thinking

Keep the 'best' things about ICE powered cars (PS, PB, PW, etc) in the EV and get rid of everything else. If I could select the single best feature of a properly designed EV, I would have to say that they take great advantage of the fact that electric motors have very high torque at very low RPM's (much like a steam engine and the opposite of a reciprocating engine) so shifting isn't needed at all like it is in an ICE car - We have such a motor which requires no conventional transmission to power the car from zero to 80 without a shift of any kind . . . . so . . . . why are we stuck with a shift lever at all???? Park could easily be electrically engaged/disengaged, just as all the other selections already are

I have a pretty confident feeling that once enough of these cars are sold and the hackers get to perfecting them, Mitsu will eventually see what we want and the 2015 version of this car will be killer!

Don

 

[PV1]

For highway coasting, you don't have to mechanically disconnect the motor from the reduction gears. An electric motor like the ones in the i and LEAF have very little drag to them without any electron flow in or out. You would cause more energy loss by having a clutch and the equipment to use it, not to mention more maintenance.

I think Mitsubishi used a conventional shifter so that anybody would know how to put the car in drive. When I test drove a LEAF, the salesperson was surprised that I knew how to start it and use the shifter in it (it's set up the same way as the Prius, but without B). Also, if you watch some videos of people's test drive in a LEAF, some of them have difficulty with it (the way they shift keeps putting it in neutral instead of D or R). What I would like to see is a push button on the side of the shifter to select D, Eco, or B (mode shown like it is now in the instrument cluster). The shifter would have four stops (P, R, N, D), and the button would toggle in the D position. Also, have a knob (like a dashboard dimmer switch) to control regen in D mode from 0 to max, but keep it fixed for Eco and B modes. Both are low cost solutions that can extend the life of the shifter (all that shifting ought to wear it out faster).

Also, I'm not sure how regen is controlled with the brake pedal, but have regen go from whatever setting it is and ramp up to full before mechanical brakes kick in. I would imagine it is already set up like this.

 

[jray3]

Good thread, I think what has the most potential for us is disabling region in D. I've got the shop manual and electrical supplement en route from HELM and will make this mod one of my first research projects.

 

[Don]

Great!

I can't wait to see a schematic. The first 'mod' I'd like to do is switch 2 wires so that the D position on the transmission selector becomes B and vice versa. Since I always use B it would be nice to have it up next to Neutral. It should also be very easy to remove a wire and have no regen at all in the D mode, which would make it coast as well as we're ever going to get it to . . . . should be the same exact thing as switching it inot Neutral

Don

 

[MLucas]

Couple of thoughts on this:

I don't know how drivers can use D or B on the highway, for me it eats up way too much energy and I drive under the speed limit and keep the A/C off.

Being a software engineer, I see a different paradigm. The motor control unit is simply a programmable interface between the batteries and the motor accepting input from the driver via the amp pedal and the mode shift lever and several other factors. The speedometer, gauges and indicators should all be replaced by a removable tablet. The tablet would come preconfigured with a standard interface and driving patterns for the shift mode. For the 'power users' they should be allowed to set the regen and power output independently on the three modes, even being able to reletter the modes on the power gauge. The tablet would also allow the driver to reconfigure the display panel, to show gauges that suit the driver best and even allow them to re-skin it to their taste if they so choose. This would definitely trump all the electric vehicles out there. But, I know this is possible because if you buy an off the shelf MCU, you can configure the drive and regen modes using a computer interface.

I don't think snipping wires is going to be the answer, best way is to find a way to program the MCU. I know from reading the Owners Manual, that I found many sections that said 'this feature can be altered by going to your dealership and having such and such reprogrammed'.

My favourite mode is actually Eco and use B for the slowing down stuff, I get the best range using those two together.

 

[JoeS]

Thank you all for your comments. I prefaced this thread by saying that I would prefer to have a joystick or paddle by the wheel to control regen. Also nice could be a rotating control to establish the throttle-off amount of regen, which everyone could set to their own liking.

I agree with MLucas that the car is software-controlled, most probably with microswitches at each mode setting merely feeding the MCU. User-configurable settings using a tablet would be wonderful. As much as I'd love to have user-configurable control over the motor, I doubt that we'll see much of this due to manufacturers' lawyers' liability fears. Even Tesla is barely dabbling in this area, at this point only providing a choice of either of two regen levels in their model S (touch-screen programmable). Hopefully, in the future...

About the only message I wanted to get across in this thread is that coasting (zero regen) should somehow be enabled as a driving mode, with adding another mode-lever position perhaps being the simplest to understand by the consumer. As it is, I am thankful for being able to pop the iMiEV into N quickly and easily and without the time delay when doing the same thing in the Leaf. And let's not forget the reason for doing this: coasting is a major range-extending trick - balancing the red needle halfway between the blue and green zone (same as coasting) is difficult to do consistently. See this section of the hypermiling thread for details:
http://myimiev.com/forum/viewtopic.php?p=1210#p1210

 

[jennrod12]

If you had a knob to control regen, you'd only need D and E. When in D you could turn the knob all the way up to mimic the current behavior in B, and turn the regen all the way down to coast. (E would still dampen the throttle pedal to reduce jack-rabbit starts.)

Jenn

 

[JoeS]

Jenn, I completely agree with you that only D and Eco would be sufficient if we had both a regen paddle/joystick and a knob to adjust the amount of pedal-up regen. Heck, we could go a step further and do away with the mode shift lever and, say, have pushbuttons (as IIRC others have suggested). The P transmission pawl actuator could perhaps be a separate lever or combined with the hand brake. Lots of possibilities, but we need to help Mitsubishi sell these things so they have an incentive to innovate.

 

[MLucas]

balancing the red needle halfway between the blue and green zone (same as coasting)

JoeS - is this the black zone between the blue and green zone? Or is it more over the Eco word? Trying to implement this in my own commute to see if I can get my numbers up there.

 

[fjpod]

I dunno know guys. I kinda like it the way it is. Simple. You know the principle of KISS?? Keep it simple stupid.

 

[tonymil]

I don't know how drivers can use D or B on the highway, for me it eats up way too much energy and I drive under the speed limit and keep the A/C off.

I believe that, because this is a single gear transmission, what mode you have it in is relevant only to acceleration, but once a cruising speed is reached, mode doesn't matter. If you're traveling at a constant 65 mph, the energy to move that 2500 pound car at that speed is the same no matter the mode.

As for the shifter, I like it and I change modes frequently. Before the MiEV I drove a manual transmission for over thirty years so it's nice to have that mechanism. I often downshifted to use engine braking on steep hills with my gas cars, so being able to shift from Eco to B when I want to slow down feels very natural.

 

[sandange]

Joe s

Jenn, I completely agree with you that only D and Eco would be sufficient if we had both a regen paddle/joystick and a knob to adjust the amount of pedal-up regen.

fjpod

I dunno know guys. I kinda like it the way it is. Simple. You know the principle of KISS?? Keep it simple stupid.

I prefer to be inter active in driving the car
But think keeping it simple would appeal more to the masses.


How about this....

Have Drive and Eco modes
Make the brake pedal the controller of the amount of regen needed and over ride to mechanical brakes at a certain point when needed

Sandy

 

[Don]

How about this....

Have Drive and Eco modes
Make the brake pedal the controller of the amount of regen needed and over ride to mechanical brakes at a certain point when needed

I think that's pretty much how it works as it came from the factory, isn't it?

Don

 

[sandange]

If that is the way the have designed it

Could you consider driving using a different method
using an un-conventional method ?
Riding the brakes to control regen levels

 

[Don]

I reread your idea, Sandy - You'd like no regen at all until engaged by the brake pedal and then control all regen by modulating the pedal. Less when you just touch it with your foot and more and more as you press harder until finally the friction brakes kick in at some point?

I suppose that could be made to work . . . . .

I think that one the car has been 'out there' for a time, all sorts of techno-geeks will begin playing with it and we'll see all sorts of neat mods that we can implement ourselves that Mitsubishi would never think of trying, largely because of a fear of litigation

Don

 

[sandange]

Don

You'd like no regen at all until engaged by the brake pedal and then control all regen by modulating the pedal. Less when you just touch it with your foot and more and more as you press harder until finally the friction brakes kick in at some point?

Yes that was my line of thought

 

[MLucas]

I believe that, because this is a single gear transmission, what mode you have it in is relevant only to acceleration, but once a cruising speed is reached, mode doesn't matter. If you're traveling at a constant 65 mph, the energy to move that 2500 pound car at that speed is the same no matter the mode.

I made a brave move yesterday coming home from work and decided to leave the mode shifter in B after crossing the Peace Bridge into Canada and brought the car up to 100 kmh, the max posted speed on the QEW. I kept the amp meter right over the Eco labelon the gauge or as close to it as possible. Seems to be its sweet spot. I made it home with 4 bars remaining on my Power Gauge, just like I always do when I keep it at 90 kmh and in Eco mode.

This kind of freaks me out, because I have totally misunderstood the modes and the transmission on this car. I feel like I have a whole new car I never knew existed before.

I've noticed that once I get the car to the desired speed and it doesn't matter what speed it is, it seems the amp meter hovers near that Eco label. Can someone explain why this is?

 

[JoeS]

balancing the red needle halfway between the blue and green zone (same as coasting)

JoeS - is this the black zone between the blue and green zone? Or is it more over the Eco word? Trying to implement this in my own commute to see if I can get my numbers up there.

MLucas - the zero-energy consumption point is indeed in the middle of the small black area between the blue and green zones. When you first "start" the car you will see the red needle settle there. While driving, I personally find it very difficult to modulate the go-pedal and keep the red needle in that position and it is far far easier for me to simply put the shift lever into N to accomplish the same thing. That is why I would like to have a driving mode which allows the car to coast when one releases the go-pedal. "Coasting" the iMiEV does not mean physically disconnecting the drivetrain, but merely electrically neither applying nor sucking power to/from the motor.

 

[fjpod]

As good as it is to get some regen, basically regen is braking, and braking means you used too much energy in the first place if you need to slow your car down.

Of course, that is a statement for a perfect world, but sometimes we need to accelerate more to stay up with traffic, or are forced to decelerate quickly.

The real rule in conserving power for improved mpg, be it gas or electric, is drive like you have no brakes (and in our cases, like you have no regen to slow the car either).