If you could request three factory add-ons, what would they be?

[flowerlandfilms]

It carries some digital data, but the audio isn't. That's why it can't carry more than two channels. The hardware could carry more, but the standard is super-old.


-Crissa

...please go to timestamp 10:58 on your own video...
...Toslink is digital, SPDIF over copper wire is digital...
...analogue audio over copper wire is analogue...

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[ajdelange]

Having an electronic diff lock ...

. Quite easy to have an electronic/software diff lock with four motors.

There is nothing "differential" about Rivians arrangement. It can indeed emulate the action of a differential but it is by no means subject to the limitations of a differential.

 

[Luke42]

The best solution is the Rivian idea with individual wheel motors. Quite easy to have an electronic/software diff lock with four motors.

There's no reason to lock the differential when you don't have one. (Like in the Rivian system.)

You just have an independent AC variable frequency drive controller (VFD) for each wheel, which allows you to control the torque and speed of each wheel independently.

If one wheel comes off the ground, it won't stop the vehicle -- the other three wheels will still provide full torque.

A differential-less 4-motor EV will move just fine on 3 wheels (at 3/4-ish power), without any special programming.

In order the prevent snapping the driveshaft when a wheel spinning in the air at full power re-connects with the ground, you would just program the motor controller not to exceed the speed the driver asks for. You already need to do something likes this in order keep an EV from doing a burnout at every stoplight.

That's where the TCS programming comes in. Having a wheel in the air should be a test case in their TDD CI/CD suite, I suppose. But an EV can just factor out a lot of traditional 4x4 problems.

The Tri-motor will be more complicated, because it's likely to contain a differential on one of the axles. I bet Tesla will use the ABS hardware to prevent excessive wheel spin when one wheel is off the ground. But that feature can be enabled all the time (it is on the gas cars which have this software feature), so you won't have to lock the diff when you leave pavement. Off-road EVs will have dramatically simpler procedures. The old-school 4x4 guys will assume it's "just" AWD, and will complain bitterly about the lack of skill required to operate EVs on the trail. [shrug]

P.S. A related question is why most EVs have sub 6-second 0-60 times And ridiculously high torque specs. The reason is that they can skip the cost and complexity having a regular transmission in the car by just butting a big electric motor (with a fixed reduction gear) in the vehicle. If you've ever driven a 1st generation Nissan Leaf, you can see why they do this -- the Leaf accelerates like an amusement park ride 0-30MPH, runs like an exonobox 30-70MPH, and peters out after that. By putting an enormous electric motor in an EV, you build a vehicle which can keep up with highway traffic while saving the cost of the transmission. Being able to trivially smoke the tires at a stop sign is a side-effect of cost-reduction which must be mitigated through software (TCS). The marketing people explain it differently, though, for obvious reasons.

 

[ajdelange]

In order the prevent snapping the driveshaft when a wheel spinning in the air at full power re-connects with the ground, you could just program the motor controller not to exceed the speed the driver asks for.

At the root of vector space control is knowing where the magnetic field of the rotor is relative to that of the stator. If a wheel breaks loose the rotor is going to get ahead of the stator field and the controller will immediately advance the phase of the stator to maintain lock. As the free wheel needs no torque the angle will be small and little torque produced meaning the power to that motor is immediately (and automatically) reduced. Thus control is through torque management, at least in the inner most loops of the control system. Obviously the outer loops are concerned with speed as that is what the driver ultimately controls.

P.S. A related question is why most EVs have sub 6-second 0-60 times And ridiculously high torque specs.

The reason is, in a nutshell, that they have electric motors which inherently have broad torque vs speed characteristics meaning that high torque is available at any speed.

Being able to trivially smoke the tires at a stop sign is a side-effect which must be mitigated through software (TCS).

The car is designed to do 0 - 60 in a certain length of time and the torque limitations are determined by that. You can always get more torque by running more current but torque stresses mechanical parts. The 0 - 60 run is at the systems torque limit. The controllers are set to limit current and angle to that which keeps torque production in the safe region. You can't ever get more torque than that. Now you can get that much torque whenever you are in the torque limited region. IOW if you want to leave every stop sign as if you are doing a 0 - 60 determination run you are free to do so and given that this is quite an experience, at least at first, many do. The result is that many Tesla owners find their tyres wearing faster than they expect (torque translates to thrust though slip). Keep that in mind next time you are tempted.

 

[Timoj]

My

There is nothing "differential" about Rivians arrangement. It can indeed emulate the action of a differential but it is by no means subject to the limitations of a differential.

My point was that with 4 motors it’s possible to have each motor turn each wheel at exactly the same speed no matter the grip conditions, functioning just like front rear and centre differential locks in a mechanical system.

 

[ScoobyDoo]

I bet if the back seats could fold up, and the front row of seats could slide forward against the wheel, there would be enough room for sleeping in the cab. Maybe not fully stretched out tho.

I'm thinking more along the line of Fords new full recline front seats. But all 6 seats line up so that its one large area. Not something I really care too much about was just thinking that's something that I haven't seen crewcab trucks accomplish yet.
Side note: I do happen to know that if you remove the passenger seat in F150 crewcab and fold up the seat behind it. At 6'2" I can lay perfectly flat in that space. Then easily replace the seat once the unexpected hailstorm passes as was in my case while camping. haha.