2019.36.1: Stopping Mode

[Saghost]

@Saghost my understanding was that for the new 1-pedal driving the braking system *is* involved? After all it’s called Hold mode, right? Not sure why the older models can’t incorporate them as well.

From my limited experience today, I’m pretty sure it is regen only until the car stops - if the music and HVAC are quiet, you can hear and feel when it transitions to vehicle hold at the end.

 

[AWDtsla]

Agreed @CRinATL.

Firstly, Tesla did do an incredible job with the brake blending, which is often imperceptible.

It's not blending, it turns on brake hold after stopped. Sometimes you even roll back an inch.

 

[THX723]

It's not blending, it turns on brake hold after stopped. Sometimes you even roll back an inch.

And what did you think ‘brake hold’ was?

 

[AWDtsla]

And what did you think ‘brake hold’ was?

Brake hold is engaged while the brakes are already under pressure.

 

[THX723]

Brake hold is engaged while the brakes are already under pressure.

Nvm. I don’t think you’re getting me.

 

[Mochomu]

They can't implement it in the same way in pre-Raven models because they only have induction motors, and the induction motors can't regen at really low RPMs, because to regen an induction motor the field has to turn slower than the rotor, with the amount of regen proprotional to the ratio of speeds, and you run out of slower speeds for the field to spin at.

(The Model 3 and Raven PMSR motors require fields that are synchronized with the rotors and adjust torque with phase timing, just like the PM motors used by the rest of the industry even though the motors are very different.)

AFAIK, there's nothing except maybe philosophical stubbornness preventing them from creating a one pedal driving mode for the pre-Raven cars that blends the brake pads in at the end, or possibly one that applies power in reverse to the rotor to stop the car.

I think they can. Based on my understanding, an induction motor doesn’t have a permanent field that induce voltage and current as it turns. So you always have to apply an external field at any RPM. When it’s really slow, you just have to slow down the exciting field also. But I guess it is a different implementation, a separate code they gave to develop. So they only decided to do that an the newer model. But if one-foot driving on a Tesla proves to be popular, they may do the same for older models. They may even have a plan, who knows.

 

[Saghost]

I think they can. Based on my understanding, an induction motor doesn’t have a permanent field that induce voltage and current as it turns. So you always have to apply an external field at any RPM. When it’s really slow, you just have to slow down the exciting field also. But I guess it is a different implementation, a separate code they gave to develop. So they only decided to do that an the newer model. But if one-foot driving on a Tesla proves to be popular, they may do the same for older models. They may even have a plan, who knows.

But to regenerate, the field always has to be slower than the rotor rotation - and if the field gets slow enough, your ability to hold poles and make it look like a contiguous field using electromagnets breaks down, and the energy needed to generate it exceeds the energy return.

I don't think regenerating an induction motor to a stop is technically feasible. Tesla certainly could, and possibly should, create a mode that emulates the experience either driving the motor backwards or using the brakes, because After a couple days driving with it I am liking Hold quite a bit.

 

[ecarfan]

Stopping Mode makes 1-pedal driving possible in many more situations, save for emergency stopping, etc.

(Former S owner here) In my Model 3 this new function is called “HOLD”; it is a new setting in the same area of the controls as CREEP and ROLL. Is HOLD called something different in the S? I don’t have that new firmware in my X yet.

 

[Saghost]

(Former S owner here) In my Model 3 this new function is called “HOLD”; it is a new setting in the same area of the controls as CREEP and ROLL. Is HOLD called something different in the S? I don’t have that new firmware in my X yet.

What you described for your 3 is what I got in my Raven X. I think pre-Raven cars are going to have the same Creep on/off that we've had for a long time, at least for now.

Tesla calling the new mode Hold inevitably leads to it getting confused with the Vehicle Hold that happens when you press and release the brake pedal on any Autopilot Tesla - which the new mode does transition to when you come to a stop.

 

[rogerbohl]

Love the new "Hold" mode. Evidently only on our "3", perhaps sadly not on our 2014 "S". On one occasion, on a steep San Francisco hill, was late to bring the "3" to a full stop. Will try again, lifting the foot earlier.

Is this one more step on the road (no pun) to recognizing and acting upon STOP signs in FSD mode?

 

[timurx]

Anyone else have what appears to be disabled stopping mode?

I can’t choose any of the options except Hold.

Thanks in advance,

 

[Saghost]

Anyone else have what appears to be disabled stopping mode?

I can’t choose any of the options except Hold.

Thanks in advance,

I think you can only switch modes while the car is on and in Park, though you can make driver profiles with different choices and switch between them on the fly.