EVerlasting
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Integrated Automatic Neutral In Drive Mode.

Sun Oct 20, 2013 12:51 am

I posted this in another thread http://www.mynissanleaf.com/viewtopic.p ... 41#p332641 in a response but I feel this is a good idea for Enhancement / Change request.

I have come across several posts in threads where LEAF owners have complained how regen actually prevents maximum achievable range. There is a missing ingredient in the LEAF that could increase range and efficiency. That ingredient is an Integrated Automatic Neutral In Drive Mode.

The LEAF coasts phenomenally in "N" Neutral. When I'm going downhill and if I'm not fast enough I switch to "N" Neutral. LEAF takes off and speeds up very quickly. When I notice that I am coming close to speed limit OR if I see cars getting close ahead of me, I switch to "D" Drive to slowdown with regen, and if I require to slow down more I switch to "Eco" and then finally brakes if required. I avoid using the brakes as much as possible. I have to be very attentive about what is going on far ahead of me and plan which mode I need to switch to before hand. It takes practise to get better at this. In any case, switching to any mode from Neutral is quick. This has helped me increase my range quite a bit. I live in a hilly area so I have to make best of going downhill.

Before I used to just use the "D" mode or "Eco" mode to go downhill and then regen when I was too fast, but I found this to be a little inefficient because I was still using some power even going downhill due to the LEAF not being able to speed up by itself with regen.

I think Nissan could have programed the LEAF in such a way that when going downhill if the grade is steep enough LEAF would automatically disengage the motor to allow the LEAF coast freely up to the speed desired by the driver through the accelerator and then intermittently engage regen when a particular speed has reached by driver input through accelerator. When the grade is not steep enough and the driver is still holding the same position on the accelerator pedal, LEAF would automatically engage the motor to maintain speed with power. When the driver wants to slow down, he/she reduces the accelerator pedal position or lets go the accelerator and again the motor gets engaged automatically to regen to slow down.

Instead what happens is that the motor is always engaged allowing either to use the power or regen but does not allow to coast freely unless done manually with Neutral as I do. (Others do this too according to another thread.)

So I think Nissan could improve this feature. Regen is not the only way to increase range especially going downhill, I think. Allowing the vehicle to intelligently coast when it can and then regen when the driver lets go the accelerator pedal would use less power and increase range. I have been doing exactly this but manually which takes a lot of attention and switching of the mode selector constantly.

BTW: I also do this when I am approaching red traffic lights from far away. When I see a red light far away and cars beginning to slow down and stop. Even in the "D' drive mode, if I let go the accelerator, my LEAF begin to slow down a little faster than other cars. In order to stay with the traffic we have to continue using a little accelerator. Instead, I switch to Neutral for a short moment to allow my LEAF to maintain speed (sometimes with other vehicles). If I feel I am going too fast, I switch to "D" or "Eco" to slow down with regen. But if I feel I slowed down too early, I switch back to Neutral again until I feel I can comfortably slow down using regen and use the brake only to stop. I know that if I was just driving regularly, I would use some power all the way to the point when I can regen to the stopping point. Instead I don't use any power AT ALL from the point I see the red light ahead of me. If Neutral was integrated in between drive and regen, I wouldn't have to do all this. The vehicle could maintain speed without power by just coasting and then regen as I let go the pedal further to slow down.
Last edited by EVerlasting on Sun Oct 20, 2013 8:58 am, edited 1 time in total.
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LeftieBiker
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Re: Integrated Automatic Neutral In Drive Mode.

Sun Oct 20, 2013 1:21 am

You probably won't see this feature added for legal reasons. The first time someone got "out of control" using it Nissan would get sued, get lots of bad press, and the car would develop a bad rep for "rolling out of control."
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TimLee
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Re: Integrated Automatic Neutral In Drive Mode.

Sun Oct 20, 2013 1:37 am

I think you make a good point.
As long as the vehicle responds to get out of the neutral condition once the brake is applied, or the accelerator position is increased; I think this would be a much more efficient way to operate an electric vehicle.
The people that have complained about using Neutral operation as an efficiency improvement based on safety concerns would have nothing to complain about on a safety basis as long as the vehicle automatically went back into normal D or Eco mode once the brake was pressed or the accelerator position was changed.
I would definitely prefer such a mode of operation to be built in than the current need to switch into neutral and then D and then Eco.
Basically an electric vehicle needs to know what grade it is on, and behave one way going downhill, and another way going up hill. Intelligent design of an electric vehicle control would have different behaviour based on what grade the vehicle is on. That is what is so wrong and incorrect and somewhat dangerous about the LEAFs built in Creep forward. It is stupidly unintelligent about what grade the vehicle is on.
So on level terrain it creeps forward way faster than most ICE vehicles with an automatic transmission.
Just downright stupid and dangerous and unintelligent design.

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DNAinaGoodWay
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Re: Integrated Automatic Neutral In Drive Mode.

Sun Oct 20, 2013 1:50 am

Clutch-less shifting, calculating relative velocities, intensly focusing on your driving, that's the fun part! Keeps you in the moment. And look at your range!

Some day, when cars all drive themselves, no one will know the joy of it.
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braineo
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Re: Integrated Automatic Neutral In Drive Mode.

Sun Oct 20, 2013 6:58 am

That is the best description of a response to - how do I improve the efficiency of every day driving?

Thanks for wording out what I do daily when I need to bring the best range from my Leaf. And yes, would love for it to be automatic.

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TickTock
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Re: Integrated Automatic Neutral In Drive Mode.

Sun Oct 20, 2013 7:31 am

I completely agree with the OP and there is nothing stopping it that I can see. It's all software. In fact, someday there could potentially be a hack to enable this. There would be no delay or safety impact since you don't shift gears or anything that would delay your ability to respond to a life threatening event. This is why to drive in D instead of ECO although I prefer the ECO accel profile. Flipping the puck is a safety risk I am unwilling to take so driving in D is the compromise for me since that at least reduces the regen when I let off and I get pretty close to zero by modulating the accelerator pedal. If I want the equivalent of engine braking, I then flip to ECO (but still only a pedal away from accel or brake so no safety impact). When I mention this in conversation with Nissan reps I am told the profiles were chosen to best match existing cars. They didn't want any drivers to notice anything "weird" about how the Leaf handles when they took a test drive. To a large extent I agree with this reasoning - when I took my wife to test drive the Rav4EV, for example, she was looking really hard for something she could latch on to for a reason not to buy it. I think this is human nature - we don't want to change and find excuses to avoid it. I think the 2013 is an improvement but don't see why a "coast when both pedals are released" profile can't be at least an option that can be enabled on request just like the door locking protocol, etc.

TimLee
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Re: Integrated Automatic Neutral In Drive Mode.

Sun Oct 20, 2013 9:48 am

The biggest deficiency that I see in the LEAF and most EVs is that they don't have an inclineometer.
Maximum efficiency and proper throttle / brake response in an EV means that the vehicle needs to know the grade that the vehicle is heading down or up.
I don't think that would be that costly or difficult to include in the vehicle.
If your iPad or other tablet can sense whether it is in Profile or Landscape orientation, how hard is it to make the vehicle know what grade it is on? :?: :?: :?: :?:

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TickTock
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Re: Integrated Automatic Neutral In Drive Mode.

Sun Oct 20, 2013 10:25 am

TimLee wrote:The biggest deficiency that I see in the LEAF and most EVs is that they don't have an inclineometer.
Maximum efficiency and proper throttle / brake response in an EV means that the vehicle needs to know the grade that the vehicle is heading down or up.
I don't think that would be that costly or difficult to include in the vehicle.
If your iPad or other tablet can sense whether it is in Profile or Landscape orientation, how hard is it to make the vehicle know what grade it is on? :?: :?: :?: :?:
I would be very surprised if it doesn't. In the service manual, it mentions that there are decel G and side G (as well as yaw) signals available on the canbus interface - primarily used by the traction control. So there is, no doubt, a downward G signal in the car, too, since you cannot buy an accelerometer without all three dimensions. However, it may not be exposed to the canbus. With these three signals, you can find the gravity vector and therefore establish the pitch (inclination) of the car. Actually for inclination, you *could* get away with just using the decel G signal. If your speed is constant, any decel detected can be assumed to be from gravity and the inclination can be computed as theta=arcsin(decel_G/9.8). If you are accelerating or decelerating you would have to compensate for that but the information is there. Maybe someday they will use it.

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Re: Integrated Automatic Neutral In Drive Mode.

Sun Oct 20, 2013 10:36 am

Yep, they are also used by the Vehicle Stability Control.
TickTock wrote:I would be very surprised if it doesn't. In the service manual, it mentions that there are decel G and side G (as well as yaw) signals available on the canbus interface - primarily used by the traction control.
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EVerlasting
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Re: Integrated Automatic Neutral In Drive Mode.

Sun Oct 20, 2013 11:04 am

If we look at the Energy Usage screen we see a circular pie chart on the left which displays Blue zone for battery power usage and below it a Green zone for regen. If Nissan develops my idea of Integrated Automatic Neutral In Drive Mode, they can add a new zone in between the Blue and Green. Perhaps a Yellow zone. This zone would display as Automatic Neutral depending on the accelerator pedal position. It doesn't have to be very big. It just needs to show if the computer is about to go towards Blue, or about to go to Green, or is perfectly in the center of Yellow zone signifying perfect coasting in Automatic Neutral. This way the driver is fully aware of his accelerator position.

On the bubble area of dash, the Automatic Neutral may remain in the Centre bubble if they don't wish to change that layout.
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