Accelerator pedal dead zone

[mane2]

Suggestion would be to remove regentravel and add regenrpm? And when you set it to 8000 for example, how would it work?

Let's say you press the pedal 20% and letting the car to accelerate slowly to speed, for example 60 km/h. Then, when you lift your foot slowly - for example so that it takes 3 seconds to reach to "off throttle", what happens? No regen until off-throttle regen hits?

What if you lift it from same speed and pedal position, but quicker. Like in one second. Would that do accelerator pedal regen?

What would define how it works, if not time?

[uhi22]

In the example with 20% throttle, you will not reach 60km/h.
Step1: At zero speed, the user pushes the pedal from 0% to 20%
Step2: ECU uses the curve for 0km/h, and the 20% result in a large acceleration.
Step3 and 4: With increasing speed, the torque goes down. When reaching 40km/h, the torque is zero.
Step5: The user releases the pedal from 20% to 10%. The software looks at the 40km/h curve at 10% pedal, and produces moderate regen torque.
Afterwards, when the speed decreases, the regen torque calms down a little bit.
If the pedal is slowly reduced from 20% instead of stepwise, we went the 40km/h line downwards a little bit, create small regen, and the speed decreases. If the pedal is hold e.g. at 15%, the stable point with zero torque is around 30km/h.
When releasing the pedal to zero immediately, the software creates always the full configured regen torque.

For me this makes sense, even if I'm used to have no "knee" at the zero-torque point, but just a straight line.

[Aragorn]

I dont think the regen travel should ever get as high as 50% of the throttle, The OEM implementations i've driven do most of this fiddling at low speeds and above that its fairly static.

[muehlpower]

Suggestion would be to remove regentravel and add regenrpm? And when you set it to 8000 for example, how would it work?

Let's say you press the pedal 20% and letting the car to accelerate slowly to speed, for example 60 km/h. Then, when you lift your foot slowly - for example so that it takes 3 seconds to reach to "off throttle", what happens? No regen until off-throttle regen hits?

What if you lift it from same speed and pedal position, but quicker. Like in one second. Would that do accelerator pedal regen?

What would define how it works, if not time?

The accelerator pedal is not primarily a "speed controller" in any car, but a torque controller that ideally reacts immediately. When you start, you press the pedal according to the desired acceleration. When you reach the desired speed, you reduce the torque until it is sufficient to overcome the current driving resistance. To go up a hill you have to push the pedal harder to keep from slowing down. There is no need for a time factor other than dampening the pedal.
The time results automatically from the mass of the vehicle and the acting torque.

[muehlpower]

I dont think the regen travel should ever get as high as 50% of the throttle, The OEM implementations i've driven do most of this fiddling at low speeds and above that its fairly static.

My suggestion is based on parameter. It may well be that a maximum of 30% pedal value at 70km/h or other values ​​turn out to be optimal. Of course, other things such as personal preferences, vehicle weight and engine performance also have an influence. Also note that in my example it is static over 100km/h, that means over 50% travel no regen at all.

[mane2]

I been testing BMW iX and iX1 recently in B mode (no creep, 1 pedal drive). I think it's actually very simple how it works: First 30% of the throttle is the regen zone (regentravel), but without dead zone.

I think setting regentravel to 30 should do the same. First 30% of throttle is power/regen .. next 70% is just throttle.

[tom91]

The way I have implemented this feature in the past and on my EVS products

So all I have is a "steady regen rpm" from which it tapers the off pedal regen to 0 at just above +/- 50-100 rpm.

Results have been very good in many vehicles from small light classic Minis to Tesla LDU powered vehicles.

[mane2]

Care to share the code? Are you using openinverter?

[muehlpower]

The way I have implemented this feature in the past and on my EVS products

image.png

So all I have is a "steady regen rpm" from which it tapers the off pedal regen to 0 at just above +/- 50-100 rpm.

Results have been very good in many vehicles from small light classic Minis to Tesla LDU powered vehicles.

This looks exactly how it is now. Dead zone of 25% ("regentravel") at e.g. 300Nm max torque and 100Nm max regeneration and the appropriate value for "regenrampstr".

[mane2]

This looks exactly how it is now. Dead zone of 25% ("regentravel") at e.g. 300Nm max torque and 100Nm max regeneration and the appropriate value for "regenrampstr".

You're right. I didn't get graph because I thought that it does not have dead zone, but it did

[tom91]

No the clue is that it has a dynamic regen based on speed so it tapers at low rpm to remove the dead zone. That is why two graphs and the arrow.

[mane2]

No the clue is that it has a dynamic regen based on speed so it tapers at low rpm to remove the dead zone. That is why two graphs and the arrow.

Ok got it. Are you using openinverter to run those motors with custom firmware?

[tom91]

LDUs is open inverter Zero-EV firmware, the others are with my own VCU running outlander motors.

[arber333]

My suggestion is based on parameter. It may well be that a maximum of 30% pedal value at 70km/h or other values ​​turn out to be optimal. Of course, other things such as personal preferences, vehicle weight and engine performance also have an influence. Also note that in my example it is static over 100km/h, that means over 50% travel no regen at all.

I am running lebowski drive in 3 cars now and i really like it. See the throttle function explanation
viewtopic.php?p=54245#p54245

What i would whish for would be several optional parameters to skew the polynomal to our need. Maybe switching between maps according to motor RPM. Do you think it could be done in OE?

[muehlpower]

No the clue is that it has a dynamic regen based on speed so it tapers at low rpm to remove the dead zone. That is why two graphs and the arrow.

That makes sense. This means if the current RPM is half the set limit and the pedal is at 0%, regen is also half the set value. Above the set RPM, the distribution of the pedal travel always remains the same. With an LDU with 400kW and 70kW regeneration, there is approx. 15% for regeneration and 85% for acceleration.

[mane2]

I just made a change to OE firmware where you can have eg. 30% dynamic regentravel without dead zone. This works exactly the same way as BMW's B-mode. Wrote bunch of unit tests to confirm it works. Next step to test it on real motor. I have one extra SDU to what I could deploy this on.

Regen "zone" - eg first 30% of pedal - activates only when you have once pushed the pedal further than 30%. When pedal is coming back to that 30% zone, regen ramps up toward 0%. Once pedal position reaches 0% or brake pedal is pressed, it resets. After reset, you again have the full 100% for gas.

[mane2]

Here's how it works. Pedal % is how much accelerator is pressed, and potnom is calculated value for torque or regen. In this example offthrottleregen is -100.

1. pedal is pressed from 0% to 100%
2. pedal is released from 100% to 20%
3. pedal is pressed from 20% to 100%

After first slight lift of the accelerator, regentravel is calculated in, so the pedal feels linear both ways, even when it's not. But this is the way commercial cars works and I never realized that before starting to think about it.

Once brake pedal is pressed, or potnom is less than 0.5, regentravel is "off", and gets again enabled after reaching that regentravel (30%) - when first time accelerator is lifted.

Code: Select all

pedal: 0% potnom: -100.099998
pedal: 1% potnom: 1.000000
pedal: 2% potnom: 2.000000
pedal: 3% potnom: 3.000000
pedal: 4% potnom: 4.000000
pedal: 5% potnom: 5.000000
pedal: 6% potnom: 6.000000
pedal: 7% potnom: 7.000000
pedal: 8% potnom: 8.000000
pedal: 9% potnom: 9.000000
pedal: 10% potnom: 10.000000
pedal: 11% potnom: 11.000000
pedal: 12% potnom: 12.000000
pedal: 13% potnom: 13.000000
pedal: 14% potnom: 14.000000
pedal: 15% potnom: 15.000000
pedal: 16% potnom: 16.000000
pedal: 17% potnom: 17.000000
pedal: 18% potnom: 18.000000
pedal: 19% potnom: 19.000000
pedal: 20% potnom: 20.000000
pedal: 21% potnom: 21.000000
pedal: 22% potnom: 22.000000
pedal: 23% potnom: 23.000000
pedal: 24% potnom: 24.000000
pedal: 25% potnom: 25.000000
pedal: 26% potnom: 26.000000
pedal: 27% potnom: 27.000000
pedal: 28% potnom: 28.000000
pedal: 29% potnom: 29.000000
pedal: 30% potnom: 30.000000
pedal: 31% potnom: 31.000000
pedal: 32% potnom: 32.000000
pedal: 33% potnom: 33.000000
pedal: 34% potnom: 34.000000
pedal: 35% potnom: 35.000000
pedal: 36% potnom: 36.000000
pedal: 37% potnom: 37.000000
pedal: 38% potnom: 38.000000
pedal: 39% potnom: 39.000000
pedal: 40% potnom: 40.000000
pedal: 41% potnom: 41.000000
pedal: 42% potnom: 42.000000
pedal: 43% potnom: 43.000000
pedal: 44% potnom: 44.000000
pedal: 45% potnom: 45.000000
pedal: 46% potnom: 46.000000
pedal: 47% potnom: 47.000000
pedal: 48% potnom: 48.000000
pedal: 49% potnom: 49.000000
pedal: 50% potnom: 50.000000
pedal: 51% potnom: 51.000000
pedal: 52% potnom: 52.000000
pedal: 53% potnom: 53.000000
pedal: 54% potnom: 54.000000
pedal: 55% potnom: 55.000000
pedal: 56% potnom: 56.000000
pedal: 57% potnom: 57.000000
pedal: 58% potnom: 58.000000
pedal: 59% potnom: 59.000000
pedal: 60% potnom: 60.000000
pedal: 61% potnom: 61.000000
pedal: 62% potnom: 62.000000
pedal: 63% potnom: 63.000000
pedal: 64% potnom: 64.000000
pedal: 65% potnom: 65.000000
pedal: 66% potnom: 66.000000
pedal: 67% potnom: 67.000000
pedal: 68% potnom: 68.000000
pedal: 69% potnom: 69.000000
pedal: 70% potnom: 70.000000
pedal: 71% potnom: 71.000000
pedal: 72% potnom: 72.000000
pedal: 73% potnom: 73.000000
pedal: 74% potnom: 74.000000
pedal: 75% potnom: 75.000000
pedal: 76% potnom: 76.000000
pedal: 77% potnom: 77.000000
pedal: 78% potnom: 78.000000
pedal: 79% potnom: 79.000000
pedal: 80% potnom: 80.000000
pedal: 81% potnom: 81.000000
pedal: 82% potnom: 82.000000
pedal: 83% potnom: 83.000000
pedal: 84% potnom: 84.000000
pedal: 85% potnom: 85.000000
pedal: 86% potnom: 86.000000
pedal: 87% potnom: 87.000000
pedal: 88% potnom: 88.000000
pedal: 89% potnom: 89.000000
pedal: 90% potnom: 90.000000
pedal: 91% potnom: 91.000000
pedal: 92% potnom: 92.000000
pedal: 93% potnom: 93.000000
pedal: 94% potnom: 94.000000
pedal: 95% potnom: 95.000000
pedal: 96% potnom: 96.000000
pedal: 97% potnom: 97.000000
pedal: 98% potnom: 98.000000
pedal: 99% potnom: 99.000000
pedal: 100% potnom: 100.000000

pedal: 99% potnom: 98.571426
pedal: 98% potnom: 97.142860
pedal: 97% potnom: 95.714287
pedal: 96% potnom: 94.285713
pedal: 95% potnom: 92.857140
pedal: 94% potnom: 91.428574
pedal: 93% potnom: 90.000000
pedal: 92% potnom: 88.571426
pedal: 91% potnom: 87.142860
pedal: 90% potnom: 85.714287
pedal: 89% potnom: 84.285713
pedal: 88% potnom: 82.857140
pedal: 87% potnom: 81.428574
pedal: 86% potnom: 80.000000
pedal: 85% potnom: 78.571426
pedal: 84% potnom: 77.142860
pedal: 83% potnom: 75.714287
pedal: 82% potnom: 74.285713
pedal: 81% potnom: 72.857140
pedal: 80% potnom: 71.428574
pedal: 79% potnom: 70.000000
pedal: 78% potnom: 68.571426
pedal: 77% potnom: 67.142860
pedal: 76% potnom: 65.714287
pedal: 75% potnom: 64.285713
pedal: 74% potnom: 62.857143
pedal: 73% potnom: 61.428570
pedal: 72% potnom: 60.000000
pedal: 71% potnom: 58.571430
pedal: 70% potnom: 57.142857
pedal: 69% potnom: 55.714287
pedal: 68% potnom: 54.285713
pedal: 67% potnom: 52.857143
pedal: 66% potnom: 51.428570
pedal: 65% potnom: 50.000000
pedal: 64% potnom: 48.571430
pedal: 63% potnom: 47.142857
pedal: 62% potnom: 45.714287
pedal: 61% potnom: 44.285713
pedal: 60% potnom: 42.857143
pedal: 59% potnom: 41.428570
pedal: 58% potnom: 40.000000
pedal: 57% potnom: 38.571430
pedal: 56% potnom: 37.142857
pedal: 55% potnom: 35.714287
pedal: 54% potnom: 34.285713
pedal: 53% potnom: 32.857143
pedal: 52% potnom: 31.428572
pedal: 51% potnom: 30.000000
pedal: 50% potnom: 28.571428
pedal: 49% potnom: 27.142857
pedal: 48% potnom: 25.714285
pedal: 47% potnom: 24.285715
pedal: 46% potnom: 22.857143
pedal: 45% potnom: 21.428572
pedal: 44% potnom: 20.000000
pedal: 43% potnom: 18.571428
pedal: 42% potnom: 17.142857
pedal: 41% potnom: 15.714286
pedal: 40% potnom: 14.285714
pedal: 39% potnom: 12.857142
pedal: 38% potnom: 11.428572
pedal: 37% potnom: 10.000000
pedal: 36% potnom: 8.571428
pedal: 35% potnom: 7.142857
pedal: 34% potnom: 5.714286
pedal: 33% potnom: 4.285714
pedal: 32% potnom: 2.857143
pedal: 31% potnom: 1.428571
pedal: 30% potnom: 0.000000
pedal: 29% potnom: -3.336667
pedal: 28% potnom: -6.673333
pedal: 27% potnom: -10.009999
pedal: 26% potnom: -13.346666
pedal: 25% potnom: -16.683332
pedal: 24% potnom: -20.019999
pedal: 23% potnom: -23.356667
pedal: 22% potnom: -26.693333
pedal: 21% potnom: -30.029999
pedal: 20% potnom: -33.366665

pedal: 21% potnom: -30.029999
pedal: 22% potnom: -26.693333
pedal: 23% potnom: -23.356667
pedal: 24% potnom: -20.019999
pedal: 25% potnom: -16.683332
pedal: 26% potnom: -13.346666
pedal: 27% potnom: -10.009999
pedal: 28% potnom: -6.673333
pedal: 29% potnom: -3.336667
pedal: 30% potnom: 0.000000
pedal: 31% potnom: 1.428571
pedal: 32% potnom: 2.857143
pedal: 33% potnom: 4.285714
pedal: 34% potnom: 5.714286
pedal: 35% potnom: 7.142857
pedal: 36% potnom: 8.571428
pedal: 37% potnom: 10.000000
pedal: 38% potnom: 11.428572
pedal: 39% potnom: 12.857142
pedal: 40% potnom: 14.285714
pedal: 41% potnom: 15.714286
pedal: 42% potnom: 17.142857
pedal: 43% potnom: 18.571428
pedal: 44% potnom: 20.000000
pedal: 45% potnom: 21.428572
pedal: 46% potnom: 22.857143
pedal: 47% potnom: 24.285715
pedal: 48% potnom: 25.714285
pedal: 49% potnom: 27.142857
pedal: 50% potnom: 28.571428
pedal: 51% potnom: 30.000000
pedal: 52% potnom: 31.428572
pedal: 53% potnom: 32.857143
pedal: 54% potnom: 34.285713
pedal: 55% potnom: 35.714287
pedal: 56% potnom: 37.142857
pedal: 57% potnom: 38.571430
pedal: 58% potnom: 40.000000
pedal: 59% potnom: 41.428570
pedal: 60% potnom: 42.857143
pedal: 61% potnom: 44.285713
pedal: 62% potnom: 45.714287
pedal: 63% potnom: 47.142857
pedal: 64% potnom: 48.571430
pedal: 65% potnom: 50.000000
pedal: 66% potnom: 51.428570
pedal: 67% potnom: 52.857143
pedal: 68% potnom: 54.285713
pedal: 69% potnom: 55.714287
pedal: 70% potnom: 57.142857
pedal: 71% potnom: 58.571430
pedal: 72% potnom: 60.000000
pedal: 73% potnom: 61.428570
pedal: 74% potnom: 62.857143
pedal: 75% potnom: 64.285713
pedal: 76% potnom: 65.714287
pedal: 77% potnom: 67.142860
pedal: 78% potnom: 68.571426
pedal: 79% potnom: 70.000000
pedal: 80% potnom: 71.428574
pedal: 81% potnom: 72.857140
pedal: 82% potnom: 74.285713
pedal: 83% potnom: 75.714287
pedal: 84% potnom: 77.142860
pedal: 85% potnom: 78.571426
pedal: 86% potnom: 80.000000
pedal: 87% potnom: 81.428574
pedal: 88% potnom: 82.857140
pedal: 89% potnom: 84.285713
pedal: 90% potnom: 85.714287
pedal: 91% potnom: 87.142860
pedal: 92% potnom: 88.571426
pedal: 93% potnom: 90.000000
pedal: 94% potnom: 91.428574
pedal: 95% potnom: 92.857140
pedal: 96% potnom: 94.285713
pedal: 97% potnom: 95.714287
pedal: 98% potnom: 97.142860
pedal: 99% potnom: 98.571426
pedal: 100% potnom: 100.000000

[uhi22]

Do I get this right: When I'm slowing down with pedal 5%, and want stronger slow down so releasing the pedal to 4, 3, 2, 1, 0%, in the end the deceleration jumps from "strong" to "nothing"? This would be a shock moment for me, seeing the brake lights of the car in front of me coming nearer.

[mane2]

Do I get this right: When I'm slowing down with pedal 5%, and want stronger slow down so releasing the pedal to 4, 3, 2, 1, 0%, in the end the deceleration jumps from "strong" to "nothing"? This would be a shock moment for me, seeing the brake lights of the car in front of me coming nearer.

At 1% it could be like -99 (very strong) and at 0% its -100.

So no jump at all, just smooth transition from -99 to -100. See the first row of data for 0%

[Aragorn]

But this is the way commercial cars works and I never realized that before starting to think about it.

Its definately NOT how the LEAF or Skoda works.

In your example, if you opened the throttle to 35%, you'd have 35% torque request. Now you reach target speed, so you reduce throttle to 25% to maintain speed and instead it goes into regen, and then you need to open the throttle back up to 44% again just to achieve the 25% you wanted.

That is NOT normal throttle control and would surely feel HORRIBLE on the road.

[mane2]

I have no idea how Toyota or Skoda does it, but BMW works very similar to that and it's not horrible at all.

I think the main thing is, that your foot does not remember the position where to lift or to what % you used to press the pedal. You lift it, and you feel what happens.

How do Skoda or Toyota do it?

[Aragorn]

i'm actually amazed that BMW would really do that TBH... Having a situation where a tiny lift of thottle takes you from +35 to -15 is going to feel awful, especially when getting back to +35 then requires a huge additional extra throttle input. A small bump in the road could cause a small lift of the throttle and suddenly your in regen instead of accelleration...

The LEAF and Skoda both seem to act similarly to me:

At zero speed, zero throttle, there is a small positive torque, upto around 5mph. Emulating "creep" from an autobox.

Once at ~5mph the zero throttle point becomes zero torque. On a flat road the car will find an equilibrium point and just roll along around 5-6mph. If a hill is encountered and the car slows the positive torque will reappear.

As the speed climbs past 5mph the zero torque point moves along the pedal travel gradually. By 10-15mph it settles in around 10-15% (my guess based on foot feel) and doesnt move further. Thus in the above example of rolling along at zero throttle, if you started going downhill, with zero throttle the car would start blending into regen once it gets past 5-6mph.

The exact zero torque point changes slightly depending on drive mode. The higher regen modes move the zero torque point slightly further into the pedal travel.

[mane2]

creep/idlespeed is another function of open inverter, let's not mix it into this one. Also speed is unrelated to accelerator, as accelerator only controls torque, not speed.

So with Skoda or Leaf, once you start accelerating and you're pressing the pedal like 35%, so you are probably applying about 35% of torque. What happens when you lift off the pedal and keep it in 15% position? Would you still be applying torque or regen? How much?

[Aragorn]

creep or not the rest of the stuff still applies.

the zero torque position moves from 0% to about 10-15% as the speed climbs from ~5 to ~10mph. Thereafter it stays put.

To answer your specific question, moving the throttle from 35% to 15% would probably be pretty close to the zero torque position, or maybe slight positive torque. Moving it back to 35% again would be exactly where it was before.

I will see if i can log throttle pedal position and torque with CarScanner and take some actual readings.

[mane2]

If you're doing 35% of the pedal, you might be going already like 60kmh or more. Having only 15% of the pedal travel for regen at that point, sounds small.

Anyway, this is that kind of thing that can only be tested by driving. It could be that my guess how BMW does it, is completely off I'll test this soon and let you know.