Rivian Rollover

[Ogre]

"Sorry Dave, I do not want to roll over."

-Some future Hummer, probably.

That’s a great way to sell classic cars for off-roading.

I’m just trying to imagine how destructive a Hummer rolling down one of the steeper routes in Moab would be. Is the body designed to withstand 9,000 pounds of truck bouncing down a mountain side? Add in the potential for a catastrophic vehicle fire and it would be a PR nightmare.

No wonder GM has a nanny mode.

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[Sonnus]

I have an R1T and have noticed major oversteer when near lock while using the highest two suspension settings. This is no surprise, most people that have lifted trucks notice this due to altered front end geometry from stock. I had the same thing in my lifted 2500HD.

I will say, the Rivian’s oversteer was much more aggressive than my 2500HD. Once you’re approaching steering lock the wheel is practically yanked from your hands in the direction you are running (oversteer). I could easily see rolling the truck on soft ground if you weren’t expecting the nasty oversteer.

If the Cybertruck has adjustable height then I would expect it will suffer from the same issue. I’m not sure there’s any good way to get around the front end geometry issue as the suspension raises and lowers.

 

[Crissa]

I have an R1T and have noticed major oversteer when near lock while using the highest two suspension settings. This is no surprise, most people that have lifted trucks notice this due to altered front end geometry from stock. I had the same thing in my lifted 2500HD.

I will say, the Rivian’s oversteer was much more aggressive than my 2500HD. Once you’re approaching steering lock the wheel is practically yanked from your hands in the direction you are running (oversteer). I could easily see rolling the truck on soft ground if you weren’t expecting the nasty oversteer.

If the Cybertruck has adjustable height then I would expect it will suffer from the same issue. I’m not sure there’s any good way to get around the front end geometry issue as the suspension raises and lowers.

The electronic torque vectoring can help a little, but really it's going to need to have electronic steering to choose to understeer the front to make up for the back needing more sideways crawl to remain in traction.

-Crissa

 

[GlockandRoll]

I've been in a roll-over truck accident offroad as a passenger, it's VERY common when turning and the front wheels dig in, and the back steps out via oversteer.

 

[chalupacabre]

When I owned a ranch, I was guilty of not donning seat beltz, too, while driving on the range. Never rolled any trucks on the ranch, though.
Any links to Rivian crash tests videos? I love the Tesla crash test videos, especially the 10T "terminator" press on the M3 roof!

 

[rlhamil]

The electronic torque vectoring can help a little, but really it's going to need to have electronic steering to choose to understeer the front to make up for the back needing more sideways crawl to remain in traction.

-Crissa

With sufficient sensors and independent control of at least front and back (and ideally with 4 motors, of each wheel) and automatically adjustable steering and profiles of needed corrections, most undesirable behavior could be compensated for. Although one still needs to be aware of special cases or recovery procedures in unusual circumstances, as the 737 Max problems showed.

 

[GlockandRoll]

With sufficient sensors and independent control of at least front and back (and ideally with 4 motors, of each wheel) and automatically adjustable steering and profiles of needed corrections, most undesirable behavior could be compensated for. Although one still needs to be aware of special cases or recovery procedures in unusual circumstances, as the 737 Max problems showed.

Not if the wheel catches a rut and digs in. It's like a catapult at that point.
this is VERY common with off-road trucks, and as such, why 4x4's carry a much higher insurance premium.

 

[JBee]

At one point, Musk said something about the air suspension playing a part in increasing turning performance. While I could see having the truck lean away from the roll being super helpful, I’m struggling to see how they could deploy it quickly enough to make a difference in a situation like this.



The time between entering a sharp turn or getting sideways, and rolling is likely less than half a second. It would take too much time to move enough air to affect this. Though maybe there are other levers they could pull. Some shocks can be adjusted quickly using magnetism. If the shocks were stiffened on the outside as the sideways motion were applied Maybe?



(Just thinking out loud here)



Aside from that, the biggest thing is to never drive with the truck in a higher than needed suspension mode.

There are heaps of vehicles with active lean control. I had a Land Rover Discovery early 2000's with active cornering from BMW, where it would lean into the corner when turning, and also lean uphill whilst doing accross a slope. Worked brilliantly and was a blast around roudabouts. Landcruiser has a Kinect system that had a passive system, that only keeps it level using a double acting hydraulic ram on the front and rear roll bar stabiliser. Not as good as the active system, but it only leaned out in the corners as much as the tyres compressed. It worked well offroad too, to put more even pressure on the wheels in uneven terrain. This system uses the principle that if both outside wheels experience a force resist, but if only one outside wheel has a force, allow wheel articulation. This is because in a corner both wheels experience a force, and in uneven terrain only one wheel experiences a bump at a time. Citroen, BMW, Audi and Porsche all have variations.

I'm hoping CT gets something like the Mercedes System. Video is worth watching, curve control starts at 3min.

 

[GlockandRoll]

Air is to slow for active body control.
The air suspension on this truck is for off road/on road variations.

 

[Ogre]

If the Cybertruck has adjustable height then I would expect it will suffer from the same issue. I’m not sure there’s any good way to get around the front end geometry issue as the suspension raises and lowers.

Cybertruck is going to be a bit more squat so should be a little less prone to this.

Aside from that, this should just be filed in the “Don’t do that” folder. Trucks with high suspension are less stable just by nature.

 

[JBee]

Air is to slow for active body control.
The air suspension on this truck is for off road/on road variations.

Um did you watch the video?

It is fast enough to compensate for corners (3min mark) and bumps using forward vision that scans the road.

Which is what Ogre was talking about.

 

[JBee]

Cybertruck is going to be a bit more squat so should be a little less prone to this.

Aside from that, this should just be filed in the “Don’t do that” folder. Trucks with high suspension are less stable just by nature.

Classic lever arm and fulcrum problem. In this case you want a shorter (lower) lever.

 

[WHIZZARD OF OZ]

As a future Cybertruck owner, I admit being torn between wanting to test the limits of my truck, and the limits of my insurance

If you get _TESLA INSURANCE_ they'll be watchin'

 

[HaulingAss]

Not if the wheel catches a rut and digs in. It's like a catapult at that point.
this is VERY common with off-road trucks, and as such, why 4x4's carry a much higher insurance premium.

The Cybertruck will have little in common with the bad handling characteristics of gasoline powered 4x4's and will be much harder to roll. Any vehicle can roll when given the right conditions and inputs, but some are much less inclined than others.

 

[Ehninger1212]

This R1T example was probably user error.

BUT it is not true that vehicles don't just randomly decide to roll over. Some do.
Very low probability with standard sedans but there is a measurably greater risk with vehicles that have high CGs like SUVs, vans and pickups.

One of the common random triggers is a tire blowout.
Even brand new, not defectively designed or under-inflate tires can blowout.

Even in an suburan or urban environment, SUVs that slides sideways on patch of ice hits a curb and the SUV rolls over or is involved in an accident where the SUV slides sideways hits a curb and the SUV rolls over.

There was a infamous series involving Ford Explorer & many badly made Firestone tires but the point here is that some vehicles are more susceptible to rollovers than others.

There is a reason many governments mandate a minimum specification for roof crush.

The National Highway Traffic Safety Administration (NHTSA) reports that some 78,000 accidents occur every year due to tire failures.

NHTSA states that “more than 10,000 people a year are killed in rollover crashes.” They account for 33 percent of all passenger vehicle fatalities.

A 2012 NHTSA sample study of 5,470 car crashes found that SUVs were the most likely type of vehicle to be involved in a rollover.

In fact, nearly half (45%) of SUVs with pre-crash tire issues rolled over. By contrast, cars, pickup trucks, and vans with pre-crash tire issues rolled over less than 25% of the time.


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Firestone and Ford tire controversy of the 1990s saw hundreds of people die in automobile crashes caused by the failure of Firestone tires installed on light trucks made by Ford
https://en.wikipedia.org/wiki/Firestone_and_Ford_tire_controversy

Police: Tire blowout caused rollover on I-95 in Stratford
Ford Econoline E250 van, in the center of three lanes when the rear passenger-side tire blew out, the report said. When the tire blew out, the report said, the driver lost control over the van, which then “rolled over onto its roof and came to a final rest in the center lane.”
By Tara O'Neill Oct. 1, 2020
https://www.ctpost.com/policereport...owout-caused-rollover-on-I-95-in-15612843.php

Tire blowout, rollover leaves one dead in Martin County
A Fort Pierce man died after the tire on his SUV blew out and he veered off Interstate 95
By Mauricio La Plante, Treasure Coast Newspapers
January 4, 2022
https://news.yahoo.com/tire-blowout-rollover-leaves-one-185714734.html

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Buying A Safer Car 2010 Valuable Information on Crash Tests, Rollover Ratings, and Safety Features
DOT HS 811 359
July 2010
https://tntrafficsafety.org/sites/default/files/buycar.pdf

.....
Electronic Stability Control (ESC),
Based on a NHTSA study of US crash data, NHTSA estimates equipping vehicles with ESC will reduce single-vehicle crashes of passenger cars by 26 percent and single-vehicle crashes of SUVs by 48 percent Preventing single-vehicle loss-of-control crashes is the most effective way to reduce deaths resulting from rollover crashes NHTSA estimates that ESC has the potential to prevent 64 percent of passenger car rollovers and 85 percent of SUV rollovers in single-vehicle crashes The same NHTSA study also found a reduction in certain multi-vehicle crashes involving SUVs

For these reasons, NHTSA recently issued a new Federal Motor Vehicle Safety Standard (FMVSS No 126) to require ESC systems on passenger cars, multipurpose passenger vehicles, trucks, and buses

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A vehicle is an inanimate object.. it cant decide to do anything..

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