Cybertruck Steer By Wire Safety Concerns and Details

[primedive]

So going around a bend slightly aggressively on a road i travel frequently my MS will *sugar* itself, flash a warning “corrective steering” applied when I’m literally in the middle of the lane perfecting going along. What happens when there’s no physical connection and the car shits itself?

Slowly but surely Tesla is removing features that have been standard on cars for decades, for good reason. No driver display, no stalks, no physical controls, no normal steering apparatus, no door handles. Do any of these things enhance my driving experience?

The driver assistance features have become stressful to use lately.
Turn on auto-steer and immediately get beeped at? Check. Get beeped at again 30 seconds later to hold the wheel even though I am? Check. Have the thing disengage because it tried to steer me into the exit and I didn’t let it? Check. Then without autosteer while merging from one highway to another, have the car freak out and say I’m departing the roadway and it’s applying corrective steering because all of the lines are faded even though I’m 8 feet from the edge? Yeah…

I don’t want features that I have to babysit or that punish me for their own failures or technical flaws. I want the car to look out for me and to reduce my cognitive burden, and to otherwise stay silent. Sometimes the car accomplishes this goal; other times, it’s just good at raising the blood pressure.

 

[NeuroRad]

The driver assistance features have become stressful to use lately.
Turn on auto-steer and immediately get beeped at? Check. Get beeped at again 30 seconds later to hold the wheel even though I am? Check. Have the thing disengage because it tried to steer me into the exit and I didn’t let it? Check. Have the car freak out and say I’m departing the roadway and it’s applying corrective steering because all of the lines are faded even though I’m 8 feet from the edge? Yeah…

I don’t want features that I have to babysit or that punish me for their own failures or technical flaws. I want the car to look out for me and to reduce my cognitive burden, and to otherwise stay silent. Sometimes the car accomplishes this goal; other times, it’s just good at raising the blood pressure.

I understand your frustration. 99% of my driving is around town. I really don’t use any of the automated features because I like driving myself. Lifetime Wh/mi 347.

 

[primedive]

Your likely right on @Sun_PSD which is why I asked for a negative owner CT review to support the viewpoint owners. Will @Sun_PSD provide one? Doubt it but that will disprove the claim that "In every single review of the CT the noise, the rumble, the poor range, the terrible fit and finish, the basic interior, the lack of 4x4 performance, etc are talked about, universally." What an inaccurate statement.

In response to the glowing praise of the Silverado EV I have no doubt owners will like it based on a couple of reviews I just watched.

Note- I've watched many CT reviews and seen one in person so no need for another positive owner video.

The recent review by throttle house is by guys who love some things about it, dislike some other things and point out the noise, fit & finish and so on. I haven’t really seen anyone “hate” the truck and definitely some people are going to interpret things how they want to, but these flaws definitely do get picked up on, even if there’s other things that they love about the truck (like its resiliency to shopping carts, haha).

 

[TessP100D]

Jury by public perception. If it had even a slight imperceptible hint at failure people would already be shouting it down from the highest mountain.

Well let’s wait on this one until Tesla has delivered more than a few overpriced toys.

 

[TessP100D]

So going around a bend slightly aggressively on a road i travel frequently my MS will *sugar* itself, flash a warning “corrective steering” applied when I’m literally in the middle of the lane perfecting going along. What happens when there’s no physical connection and the car shits itself?

Slowly but surely Tesla is removing features that have been standard on cars for decades, for good reason. No driver display, no stalks, no physical controls, no normal steering apparatus, no door handles. Do any of these things enhance my driving experience?

Most of those items you just stated are dangerous to remove.

 

[TessP100D]

The recent review by throttle house is by guys who love some things about it, dislike some other things and point out the noise, fit & finish and so on. I haven’t really seen anyone “hate” the truck and definitely some people are going to interpret things how they want to, but these flaws definitely do get picked up on, even if there’s other things that they love about the truck (like its resiliency to shopping carts, haha).

Oh and the latest…. The engineers took 5 years to design a hub cap that doesn’t work properly. Amazing.

 

[ThomasD]

Is the rear steer turning angle less in tow mode at slow speeds when making sharp turns with a Trailer?

 

[Daniel in SD]

Is the rear steer turning angle less in tow mode at slow speeds when making sharp turns with a Trailer?

I don’t think they’ve enabled very much steering angle yet so probably not.

 

[Nack]

I don't believe Tesla's drive by wire is at all a similar system so don't go by Audi and Lexus. Everyone who drives the CT seems very happy with how it works. That is certainly different then feedback I've heard from other "similar" systems. I do agree with you that having Tesla provide some information on how it works would be helpful. I do remember hearing on Jay Leno's CT review there is triple redundancy.

This video is helpful.

Is there still a physical shaft connecting? Im curious what the triple redundancy is beyond multiple steering angle sensors. That really would only address one failure mode though.

We will probably have to wait and see, but the HaRa can be manipulated to say all failure modes are covered if you are looking to get that result whether its actually true or not.

 

[Suns_PSD]

Your likely right on @Sun_PSD which is why I asked for a negative owner CT review to support the viewpoint owners. Will @Sun_PSD provide one? Doubt it but that will disprove the claim that "In every single review of the CT the noise, the rumble, the poor range, the terrible fit and finish, the basic interior, the lack of 4x4 performance, etc are talked about, universally." What an inaccurate statement.

In response to the glowing praise of the Silverado EV I have no doubt owners will like it based on a couple of reviews I just watched.

Note- I've watched many CT reviews and seen one in person so no need for another positive owner video.

Owner reviews, unless the owner just purchased to test and flip, are generally less trustworthy.

A professional reviewer is much more likely to have less positive confirmation bias as a result of their personal major investment.

 

[aronth5]

Owner reviews, unless the owner just purchased to test and flip, are generally less trustworthy.

A professional reviewer is much more likely to have less positive confirmation bias as a result of their personal major investment.

@Suns_PSD still waiting for a link from you to an owner or professional reviewer that substantiates:
"In every single review of the CT the noise, the rumble, the poor range, the terrible fit and finish, the basic interior, the lack of 4x4 performance, etc are talked about, universally."

I also asked for a review of the Silverado EV truck which your praised. However, since you didn't provide a link I went looking and found a couple that were favorable. Very good range of 450 miles which one reviewer verified. One has to wonder if GM can make any money though on the Silverado EV truck with an estimated 200 kWh battery compared to the Cybertrucks estimated 123 KWh battery pack which explains why the CT range is less than most thought. If GM cannot make a profit that is serious problem.

 

[vcor]

Is there still a physical shaft connecting? Im curious what the triple redundancy is beyond multiple steering angle sensors. That really would only address one failure mode though.

There is no physical shaft from the steering wheel to the steering rack, unlike the Lexus and Audi.

Only an electrical connection, similar to the way airplane controls are designed. The front steering rack has redundant motors and uses redundant power connections, and the steering wheel position sensor is triple redundant. Beyond that, I don't think much more has been released by Tesla.

It's not clear what, if any, redundancies are used in the Lexus/Audi systems. My guess is there are no redundancies, as it relies on the mechanical system as backup, which means it can't offer anything like the Cybertruck's speed-sensitive ratio changes.

 

[Daniel in SD]

There is no physical shaft from the steering wheel to the steering rack, unlike the Lexus and Audi.

Only an electrical connection, similar to the way airplane controls are designed. The front steering rack has redundant motors and uses redundant power connections, and the steering wheel position sensor is triple redundant. Beyond that, I don't think much more has been released by Tesla.

It's not clear what, if any, redundancies are used in the Lexus/Audi systems. My guess is there are no redundancies, as it relies on the mechanical system as backup, which means it can't offer anything like the Cybertruck's speed-sensitive ratio changes.

They do have speed sensitive ratio changes. The BMW uses a planetary gear setup driven by the steering wheel and a motor (note this is not the power steering motor, the bmws might be hydraulic assist, not sure.) In the event of motor failure it’s able to lock to a fixed ratio.

 

[dbeiler]

My guess is there are no redundancies, as it relies on the mechanical system as backup, which means it can't offer anything like the Cybertruck's speed-sensitive ratio changes.

Ratio changes are possible and even quite common on mechanical systems. Lincoln's system contains a mechanism inside the steering wheel, where the steering wheel would normally be permanently fixed to the steering shaft. Turning the steering wheel does not always result in a one-to-one turn of the steering column shaft. The mechanism increases or decreases the rotational speed of the shaft in relation to the steering wheel.

Even the most basic, $23K version of the Honda Civic now comes with a variable ratio steering system.

 

[vcor]

Yep, understand there are many cars with slight variable-ratio steering. Some of the cheap systems are not speed-aware either (changes the ratio based on speed). I'm not aware any of these systems are close to the range of ratio that the Cybertruck uses with about 170 degrees lock to lock. I sort of doubt it is possible to mechanically duplicate the range of variable ratio that Tesla uses, but perhaps someone else has done it on a production vehicle.

The key is it makes a large heavy truck drive like a light-performance car. Comparing it to a Honda Civic is rather silly, but entertaining! The Civic also has four wheels, so it must be just as good as a Porche 911, or a McLaren 750S.

 

[Nack]

There is no physical shaft from the steering wheel to the steering rack, unlike the Lexus and Audi.

Only an electrical connection, similar to the way airplane controls are designed. The front steering rack has redundant motors and uses redundant power connections, and the steering wheel position sensor is triple redundant. Beyond that, I don't think much more has been released by Tesla.

It's not clear what, if any, redundancies are used in the Lexus/Audi systems. My guess is there are no redundancies, as it relies on the mechanical system as backup, which means it can't offer anything like the Cybertruck's speed-sensitive ratio changes.

Thanks for the info. All that is pretty common in steering systems that are electric assist racks that still have the steering shaft. I'm curious what Tesla did to make the steering shaft redundant as that's the concern. On other steering systems if you have an issue with the redundant systems, you can still steer without the power assist....it's just not fun but you can maneuver to the side of the road. Armstrong steering In this case I guess you are just along for the ride! I'll have to read up more about the other steer by wire systems to see how they implemented.

 

[Skotty]

So I'm getting a lot of down votes here for feeling dubious about steer by wire, and that's fine. Hopefully it will be reliable in the Cybertruck. But this kind of thing is why I'm rather untrusting on steer by wire: Model 3 Loses Power Steering? UI_a020 . Go ahead...down vote me some more on this post now just for the giggles, I don't mind, it's all good fun.

 

[Daniel in SD]

So I'm getting a lot of down votes here for feeling dubious about steer by wire, and that's fine. Hopefully it will be reliable in the Cybertruck. But this kind of thing is why I'm rather untrusting on steer by wire: Model 3 Loses Power Steering? UI_a020 . Go ahead...down vote me some more on this post now just for the giggles, I don't mind, it's all good fun.

Model 3 doesn’t have redundant power steering motors. Though it was claimed to be suitable for robotaxi use. I recall that it has redundant control circuitry.
There is a recall of 300k 2023 model 3 and y for power steering failure.

 

[vcor]

... I'm curious what Tesla did to make the steering shaft redundant as that's the concern. On other steering systems if you have an issue with the redundant systems, you can still steer without the power assist....it's just not fun but you can maneuver to the side of the road. ...

I can see many reasons for ditching the steering shaft:

1) With a large heavy truck and 35" tires, using the mechanical system without power steering could be very difficult to steer (more so than cars/light trucks), so it could be a dangerous backup to use the mechanical shaft if power steering fails for this application
2) Possible weight reduction (although redundant motors may negate this)
3) Possible improved safety (cars with mechanical shafts are a bit complex to deal with collapsing the column in a crash so it doesn't impale the driver)
4) Less physical space required
5) Makes it far easier to make both RHD and LHD versions.
6) No steering components have to breach the firewall (easier assembly, reduced noise and vibration)
7) Offers dramatic speed-sensitive steering not possible with mechanical systems (there are slight speed-sensitive mechanical systems)
8) The ability to fully control how much feedback and road vibration is passed to the driver
9) Software updates can improve the system more than would be possible with a mechanically linked system

On the downside:

1) It's likely more expensive
2) More complex to design
3) Users being uncomfortable with steer-by-wire that they've never used before (New can be scary to some)
4) No mechanical backup

 

[Nack]

...

1) With a large heavy truck and 35" tires, using the mechanical system without power steering could be very difficult to steer (more so than cars/light trucks), so it could be a dangerous backup to use the mechanical shaft if power steering fails for this application

...

I'm not sure about that. It's a test performed on semi-trucks to ensure if the power steering assist goes out you can still maneuver the vehicle. This is all about having the correct design, so you have enough mechanical leverage to work in the situation.

Something like the Cybertruck would be much easier to maneuver without power steering than a semi-truck.