Thank you for doing this test and proving that the system works but needs more fine tuning. This not only inspires more off road confidence and shows how to use the throttle but clears up a lot of confusion for the naysayers. Now its up to Rivian to make it even better with the virtual locker mode. Spread the word in the forums so that they make that option!
Great test. As others mentioned would like to see the same with a dual motor. I have a little experience in control systems and would like to make some observations about what I see here and the 'simulated locker' you desire. Without a bunch of math I'll talk about two kinds of control systems, velocity based and distance based. Velocity based systems are the most familiar. These work by looking at the error between the velocity of the given system and the set velocity. Obvious examples are the cruise control on your vehicle. You set some speed, the cpu counts wheel rotations, divides by time, calculates the error and steps on the pedal more if low or less if high. A not so obvious example is the nearly identical system of wheel control in the Rivian and most any other vehicle. The driver is part of the control system and steps on the pedal depending on the error he sees between what he wants and what the vehicle is doing. The system looks at the pedal position and tries to make the speed match some algorithm. Remember, as you noted the Rivain seems to have no concept of wheel position, only wheel velocity. It looks for velocity errors when you are hoping for position, ie move all wheels 1 inch forward off the ramp. I contend that the 'simulated locker' you desire is not that velocity based system. What you want is a position based system, think of a milling machine xy table or servo motor where you set the position and the system goes to it. One position based system we're all familiar with is power steering. Whether electric or hydraulic we set a steering wheel position and the car turns the wheels to that position, with great force if required. Now imagine (lots of imagination) that the power steering system was controlling your vehicle wheels rotation instead. A quarter turn of the steering wheel would rotate all tires a quarter turn. Turning left would backup and right would forward. There would be no wheels spinning in the air unless you spun the steering wheel. Of course steering wheel control would be impractical, even with a speed knob on the steering wheel, but think of the forward aft control! I think the Rivian has the hardware to have this kind of control. 'Rock crawl mode' as currently implemented doesn't use it and should. As far as code, the guts of a PID (Proportional Integral Differential) controller is only about 10 lines of code but isn't off the shelf and would probably require several 100 lines of code to integrate with the existing velocity based system.
beauty of the rivian 4 motor setup is locking the wheels so front/rear/ all are locked to turn at the same speed no matter what should be a trivial software change assuming rivian will do it.
There's likely a minimum rotational speed for the sensors to register how fast the wheels are rotating, once the spinning wheels get to that speed, the system knows to apply more torque to the one that's not spinning.
if you really sit and think about it, it's not trivial at all. the power required to match wheel speeds is constantly varying, it's a moving target. this is approximately as good as it will ever get.
Thanks for putting this together. Planning a trip out West with my Rivian R1S (Moab, Brocken Arrow, etc). It’s good to know if slow doesn’t do it, smash it a little.
Awesome testing AJ and EVlander, you guys were very very thorough! Looking forward to bringing the Honda on this test. You need to add LED buzzers to indicate if the tires touch the sides, which would help a vehicle drive off the rollers.
Definitely something we were keeping an eye on. In the case with these 2 tested vehicles it was obvious that the torque going to only one wheel with traction was not the limiting factor to pass the 3 roller test. The real challenge with the Rivian was pedal application.
What works for my Rivian is actually holding the brake pedal and apply a lot of throttle (ok maybe not too much) and release the brake slowly. I got the less tire spin and the most power. I wish you tested that as well :)
Great video! Thank you for going through this. Now that you've had some more time since learning this, have you had other real world examples since this where your new method (quick pedal mashing) worked?
I think it was ingenious that Ford added a locker to all F150 Lightning models. Rivian seemed to overcome it with the quad motor which promises individual wheels controlled independently, but clearly this isn't a replacement for a true locker.
I was expecting to see Rivian in the comments saying "Consider it done", but no. And I don't know if they're in the EV game for performance, luxury, or the environment. But if its for the last one, then they really need simulated lockers, because this current system looks like it just digs holes, rips up the ground & tires for no good reason. That locker example you showed was so quick & efficient. Maybe it's best to convert an engine truck to a BEV or Series Hybrid with a small generator to charge the batteries, and you just replace the drive engine, with one or more electric motors, sending power through the normal transmission & lockers. I love the idea of motors at each wheel, for handling tricks like vector steering, and tank turns. But lockers are amazing, are easy to work on I'm guessing, and don't require deep computer knowledge, hacking, or begging the damn 4 motor vehicle manufacture, and waiting for them to update the programming.
There is nothing more frustrating (and sometimes dangerous) off-road than software limiting what a vehicle can do. These EVs really need a nanny kill switch. Lockers too, obviously.
It’s worth noting that, on the Rivian (both R1T/R1S), the more you press the accelerator, not only does more power go to the single wheel, I think the computer tries to figure out traction quicker. Not entirely sure though.
Awesome video and testing! Thank you. I really like the Tundra, but bought and love my R1T. A deficit of the Tundra is no all-wheel drive, on pavement...am I correct on that...only "part-time, old school 4-wheel on the Tundra?
Great testing! Are you thinking of repeating this test for the dual motor version? I am wondering how well it will perform without the same off-roading modes.
We would love to do this. The quad is the flagship so I don't think they will make it better than the quad. Dual motor only has one mode for offroad (All Terrain)
We have about 200 Trail Swings that we are currently working on, welding, and assembling everyday. We work nights and weekends. Unfortunately it's not a matter of how hard we ourselves work, but how fast our supply chain works. For example, in order to get you, the customer, the best price we would have to order a mill run of 2,000 to 4,000 feet of chromoly tubing. Today they tell us we are 5-6 months out on material, assuming nothing is delayed on the supply end, which in recent history has not been the case. Thank you for your patience!
@@DirtComplex You guys need to communicate this to your customers rather than just not answering emails or phone calls like has been going on the past few weeks at least. Also your web site still lists a 6-8 week lead time on the Trail Swing. I've been waiting over 16 weeks and other customers are reporting delays up to 19 weeks or longer. If you ignore your customers then they're just going to go somewhere else.
The rear locker also is controlled by software. The BCM has to receive the signal to lock. The locker has to electronically engage. It’s actually not as convenient. You have to stop. Engage it. Then go.
Yes true, but once engaged it will out crawl the Rivian with ease and gracefulness. The Toyota was used to show how powerful a locker is in general. Whether a locker is mechanical, air, or electronic, once engaged it is quite powerful. Also in the ideal scenario you are engaging the locker before the obstacle and usually the obstacle is low speed. Furthermore, the Toyota E-locker can be easily wired up as a simple on and off switch. I've done a few that way in the past to bypass the 2 high and 4 high restrictions. Obviously not recommended by the manufacturer hahahah. Thanks for checking out the video and commenting. Much appreciated!
Thank you!!! Really confusing why Rivian hasn't provided a simulated rear-locker mode? Any speculation as to what concerns they might have? I completely understand the safety concerns of tank-turn mode, but really can't think of any safety concerns stemming from a simulated rear-locker. In fact, it seems it would be safer in most rock-crawl scenarios.
Theoretically they have a higher resolution of control than any brake based traction control system, so the answer eludes me. It would be a great feature to release to differentiate the quad motor from the dual motor Rivians that will be cruising the streets soon.
I believe it is for marketing reasons. The quad motor is the flagship. If the dual motor is better or just as good then there is no incentive to upgrade. Currently the dual motor only has 1 offroad mode (all purpose) while the quad motor has 5.
I really wish Rivian would have put in a software locker mode. It would have been so easy, no? My guess is the guys building it don't really know what game changers physical lockers are, because they are from Michigan. I always have lockers in my offroad rigs. I'm not expecting much from my R1T when it hits the dirt this fall after the desert cools down, especially with the weak tie rods and the Perreli "all-terrains", but hey, it's not purpose built to keep up with the jeeps. I just feel like they left a lot of capability on the table by not offering virtual lockers front and rear.
the internet is full of comments just like yours, assuming they just aren't aware. the reality is, it's impossible to simulate a locker and that's why no one has done it. The computer can't accurately guess what torque each wheel needs in a changing environment. you can just send the same power to each wheel, but then you create a tire shredder and snap axles, etc.
Would think it’s just a matter of time before they figure out a software emulated triple lock (front/center/rear) while also avoiding any binding during turns.
It should be possible to do an enhanced “triple locker” where each wheel turns at exactly the right rate based on the steering angle. That way there would be no spinning AND no binding, even better than traditional mechanical lockers.
Offroading is a very broad term. I would say the Rivian is amazing at everything offroad except for low speed crawl scenarios where a locker is king. However, medium, high speed, handling, and drifitng with the near 51/49 weight distribution it is really fun to drive. McLaren style suspension makes this handle amazing. Instant torque gives great handling at higher speed corners traveling through the desert. Comfort at medium and high speed is unmatched since it is IRS as well. We have never driven anything like it. But yes, low speed crawling is frustrating.
Yes that is true with any vehicle. To put it bluntly though compared to a vehicle with a rear locker the R1T sucks at crawl mode. Otherwise it is amazing at everything else on and off road.
So just buy the duel motor Rivian and install a real locker front and rear. Or wait till rivian pulls their head of out their ass and comes out with a 1 line of code to make a “simulated” locker mode : Wheel speed must = same left / right Why is that so hard. What a waste.
I’m reasonably sure it would be a lot more than one line of code. And there may be secondary issues or implementation details that no one outside of Rivian can know. That said, I suspect that it would be a fairly easy job. My guess is that either they just don’t care because rock crawling isn’t a significant part of their market OR all their engineers are busy with something they consider more important (like getting the dual motor version working). But to be honest, they should get rid of Rock Crawl mode until they can make it work right.
@@WilliamAArnett not really … left wheel speed = right wheel speed . The end . If they really wanted to optimize a quad motor to its full potential, then it would be much more complicated with things like tank, turn, or pivoting, only allowing the wheel with the most traction spin.
I will never sell my V8 4runner. We have different tools for different jobs. Same with our trucks. However, the Rivian R1T is an amazing feat of engineering and once you experience one it is hard to hate it.
Thank you for doing this test and proving that the system works but needs more fine tuning. This not only inspires more off road confidence and shows how to use the throttle but clears up a lot of confusion for the naysayers. Now its up to Rivian to make it even better with the virtual locker mode. Spread the word in the forums so that they make that option!
Great test. As others mentioned would like to see the same with a dual motor.
I have a little experience in control systems and would like to make some observations about what I see here and the 'simulated locker' you desire. Without a bunch of math I'll talk about two kinds of control systems, velocity based and distance based.
Velocity based systems are the most familiar. These work by looking at the error between the velocity of the given system and the set velocity. Obvious examples are the cruise control on your vehicle. You set some speed, the cpu counts wheel rotations, divides by time, calculates the error and steps on the pedal more if low or less if high.
A not so obvious example is the nearly identical system of wheel control in the Rivian and most any other vehicle. The driver is part of the control system and steps on the pedal depending on the error he sees between what he wants and what the vehicle is doing. The system looks at the pedal position and tries to make the speed match some algorithm. Remember, as you noted the Rivain seems to have no concept of wheel position, only wheel velocity. It looks for velocity errors when you are hoping for position, ie move all wheels 1 inch forward off the ramp.
I contend that the 'simulated locker' you desire is not that velocity based system. What you want is a position based system, think of a milling machine xy table or servo motor where you set the position and the system goes to it. One position based system we're all familiar with is power steering. Whether electric or hydraulic we set a steering wheel position and the car turns the wheels to that position, with great force if required.
Now imagine (lots of imagination) that the power steering system was controlling your vehicle wheels rotation instead. A quarter turn of the steering wheel would rotate all tires a quarter turn. Turning left would backup and right would forward. There would be no wheels spinning in the air unless you spun the steering wheel. Of course steering wheel control would be impractical, even with a speed knob on the steering wheel, but think of the forward aft control!
I think the Rivian has the hardware to have this kind of control. 'Rock crawl mode' as currently implemented doesn't use it and should. As far as code, the guts of a PID (Proportional Integral Differential) controller is only about 10 lines of code but isn't off the shelf and would probably require several 100 lines of code to integrate with the existing velocity based system.
Easily the best comment on this video. Too bad nobody cares about control systems, only the results of a well made one 😂
beauty of the rivian 4 motor setup is locking the wheels so front/rear/ all are locked to turn at the same speed no matter what should be a trivial software change assuming rivian will do it.
Exactly. Having loose wheels spinning and kicking dirt and rocks everywhere is not an elegant way of crawling over terrain....
They should have a “ V locker “ mode and spin all 4 at the same rate as if it was locked
There's likely a minimum rotational speed for the sensors to register how fast the wheels are rotating, once the spinning wheels get to that speed, the system knows to apply more torque to the one that's not spinning.
if you really sit and think about it, it's not trivial at all. the power required to match wheel speeds is constantly varying, it's a moving target. this is approximately as good as it will ever get.
Thanks for putting this together. Planning a trip out West with my Rivian R1S (Moab, Brocken Arrow, etc). It’s good to know if slow doesn’t do it, smash it a little.
This videos is super informative! Thank you guys for all you do!!!
🍻
Really excellent testing, camera work, graphics on which tires, and the video insert clips to go along with it. Very informative.
Thanks much appreciated!
Yes PLEASE test DUAL motor. Great video!
This is a super informative video. Thanks for putting the work into this.
Thanks for watching!
missin u, tech of twang :/
Awesome testing AJ and EVlander, you guys were very very thorough! Looking forward to bringing the Honda on this test. You need to add LED buzzers to indicate if the tires touch the sides, which would help a vehicle drive off the rollers.
Definitely something we were keeping an eye on. In the case with these 2 tested vehicles it was obvious that the torque going to only one wheel with traction was not the limiting factor to pass the 3 roller test. The real challenge with the Rivian was pedal application.
Nice testing, I have a Rivian on order, hopefully they do an over the air update and add a simulated locker which is much needed.
What works for my Rivian is actually holding the brake pedal and apply a lot of throttle (ok maybe not too much) and release the brake slowly. I got the less tire spin and the most power. I wish you tested that as well :)
Great video! Thank you for going through this. Now that you've had some more time since learning this, have you had other real world examples since this where your new method (quick pedal mashing) worked?
I think it was ingenious that Ford added a locker to all F150 Lightning models. Rivian seemed to overcome it with the quad motor which promises individual wheels controlled independently, but clearly this isn't a replacement for a true locker.
I was expecting to see Rivian in the comments saying "Consider it done", but no. And I don't know if they're in the EV game for performance, luxury, or the environment. But if its for the last one, then they really need simulated lockers, because this current system looks like it just digs holes, rips up the ground & tires for no good reason. That locker example you showed was so quick & efficient.
Maybe it's best to convert an engine truck to a BEV or Series Hybrid with a small generator to charge the batteries, and you just replace the drive engine, with one or more electric motors, sending power through the normal transmission & lockers.
I love the idea of motors at each wheel, for handling tricks like vector steering, and tank turns. But lockers are amazing, are easy to work on I'm guessing, and don't require deep computer knowledge, hacking, or begging the damn 4 motor vehicle manufacture, and waiting for them to update the programming.
There is nothing more frustrating (and sometimes dangerous) off-road than software limiting what a vehicle can do. These EVs really need a nanny kill switch. Lockers too, obviously.
It’s worth noting that, on the Rivian (both R1T/R1S), the more you press the accelerator, not only does more power go to the single wheel, I think the computer tries to figure out traction quicker.
Not entirely sure though.
Regardless, it ends up being a jerky and uncontrolled off-road experience compared to a vehicle with locking differentials.
Yeah it's definitely a combination of both. Thanks for watching!
@@CallsignVega is it really jerky? I haven’t tried it yet.
@matthewgoat91515 & @justinstewart3248 They definitely talk about this at 18:17 - when he floors the pedal.
Awesome video and testing! Thank you. I really like the Tundra, but bought and love my R1T. A deficit of the Tundra is no all-wheel drive, on pavement...am I correct on that...only "part-time, old school 4-wheel on the Tundra?
Thanks! Yeah. Tundra is only part time. However the 4runner Limited and now the new 2024 Tacoma Limited will have full time 4WD capabilities.
Great testing! Are you thinking of repeating this test for the dual motor version? I am wondering how well it will perform without the same off-roading modes.
We would love to do this. The quad is the flagship so I don't think they will make it better than the quad. Dual motor only has one mode for offroad (All Terrain)
I love this content . But with that being said I wish you were working on getting me my Trail Swing.
We have about 200 Trail Swings that we are currently working on, welding, and assembling everyday. We work nights and weekends. Unfortunately it's not a matter of how hard we ourselves work, but how fast our supply chain works. For example, in order to get you, the customer, the best price we would have to order a mill run of 2,000 to 4,000 feet of chromoly tubing. Today they tell us we are 5-6 months out on material, assuming nothing is delayed on the supply end, which in recent history has not been the case. Thank you for your patience!
@@DirtComplex You guys need to communicate this to your customers rather than just not answering emails or phone calls like has been going on the past few weeks at least. Also your web site still lists a 6-8 week lead time on the Trail Swing. I've been waiting over 16 weeks and other customers are reporting delays up to 19 weeks or longer. If you ignore your customers then they're just going to go somewhere else.
The rear locker also is controlled by software. The BCM has to receive the signal to lock. The locker has to electronically engage. It’s actually not as convenient. You have to stop. Engage it. Then go.
Yes true, but once engaged it will out crawl the Rivian with ease and gracefulness. The Toyota was used to show how powerful a locker is in general. Whether a locker is mechanical, air, or electronic, once engaged it is quite powerful. Also in the ideal scenario you are engaging the locker before the obstacle and usually the obstacle is low speed. Furthermore, the Toyota E-locker can be easily wired up as a simple on and off switch. I've done a few that way in the past to bypass the 2 high and 4 high restrictions. Obviously not recommended by the manufacturer hahahah. Thanks for checking out the video and commenting. Much appreciated!
I would like to see the same tests on a HummerEV.
We would love to do that test. Where are the volunteer tributes! hahah
Thank you!!! Really confusing why Rivian hasn't provided a simulated rear-locker mode? Any speculation as to what concerns they might have? I completely understand the safety concerns of tank-turn mode, but really can't think of any safety concerns stemming from a simulated rear-locker. In fact, it seems it would be safer in most rock-crawl scenarios.
Theoretically they have a higher resolution of control than any brake based traction control system, so the answer eludes me. It would be a great feature to release to differentiate the quad motor from the dual motor Rivians that will be cruising the streets soon.
Sadly, there is no indication of a locker in the 2-motor version. Why?
I believe it is for marketing reasons. The quad motor is the flagship. If the dual motor is better or just as good then there is no incentive to upgrade. Currently the dual motor only has 1 offroad mode (all purpose) while the quad motor has 5.
I really wish Rivian would have put in a software locker mode. It would have been so easy, no? My guess is the guys building it don't really know what game changers physical lockers are, because they are from Michigan. I always have lockers in my offroad rigs. I'm not expecting much from my R1T when it hits the dirt this fall after the desert cools down, especially with the weak tie rods and the Perreli "all-terrains", but hey, it's not purpose built to keep up with the jeeps. I just feel like they left a lot of capability on the table by not offering virtual lockers front and rear.
the internet is full of comments just like yours, assuming they just aren't aware. the reality is, it's impossible to simulate a locker and that's why no one has done it. The computer can't accurately guess what torque each wheel needs in a changing environment. you can just send the same power to each wheel, but then you create a tire shredder and snap axles, etc.
What's the water/fluid on the floor? Nice test!!
The A/C was on the entire time. It was most likely condensation build up from being on in the same place for a couple hours.
Would think it’s just a matter of time before they figure out a software emulated triple lock (front/center/rear) while also avoiding any binding during turns.
That would be ideal. Binding during turns is not a deal breaker though at low speed crawling though. At the very least give us the rear!
It should be possible to do an enhanced “triple locker” where each wheel turns at exactly the right rate based on the steering angle. That way there would be no spinning AND no binding, even better than traditional mechanical lockers.
That sucks... having tight control when rock crawling is critical.
RIvian is actually pretty crappy off-road due to no axle locking and heavy weight. Having four motors doesn't replace having differential lockers.
Offroading is a very broad term. I would say the Rivian is amazing at everything offroad except for low speed crawl scenarios where a locker is king. However, medium, high speed, handling, and drifitng with the near 51/49 weight distribution it is really fun to drive. McLaren style suspension makes this handle amazing. Instant torque gives great handling at higher speed corners traveling through the desert. Comfort at medium and high speed is unmatched since it is IRS as well. We have never driven anything like it. But yes, low speed crawling is frustrating.
Can we Collaborate on RIvian accessories about your TH-cam?
Send us an email! Our website is dirtcomusa.com
@@DirtComplex sure ,will send to you now
@@DirtComplex hi ,i email you ,please have a check
Dude crouched behind the truck.....won't feel good if that wheel sends something in your direction!
Or the owners can learn to drive in each mode.........
Yes that is true with any vehicle. To put it bluntly though compared to a vehicle with a rear locker the R1T sucks at crawl mode. Otherwise it is amazing at everything else on and off road.
So just buy the duel motor Rivian and install a real locker front and rear. Or wait till rivian pulls their head of out their ass and comes out with a 1 line of code to make a “simulated” locker mode : Wheel speed must = same left / right Why is that so hard. What a waste.
Hopefully soon. Thanks for watching!
I’m reasonably sure it would be a lot more than one line of code. And there may be secondary issues or implementation details that no one outside of Rivian can know. That said, I suspect that it would be a fairly easy job. My guess is that either they just don’t care because rock crawling isn’t a significant part of their market OR all their engineers are busy with something they consider more important (like getting the dual motor version working).
But to be honest, they should get rid of Rock Crawl mode until they can make it work right.
@@WilliamAArnett not really … left wheel speed = right wheel speed . The end . If they really wanted to optimize a quad motor to its full potential, then it would be much more complicated with things like tank, turn, or pivoting, only allowing the wheel with the most traction spin.
No offense to you guys but I hate electric trucks. 🤮
Why?
It shouldn't be an offense. You don't have to like everything
I will never sell my V8 4runner. We have different tools for different jobs. Same with our trucks. However, the Rivian R1T is an amazing feat of engineering and once you experience one it is hard to hate it.
@@DirtComplex I need to hear that engine brother, that V8. Electric trucks are more for rich people that like toys for now they can’t really do work.
@@manuelias86 - show us your truck