Comma Ai / Comma 4 drive on unmapped roads (video)

[LivingInKaos]

I'm running Nokian One HTs (22") Based on the data i shared I was told i was at 2.2-2.3 m/s2 on my R1S

Do you need more data to help expand that list ?

@gerrylum has been quite busy testing things behind the scenes, so if your values aren't on that list, I'm sure he's just been too busy to get it updated just yet. I'm not sure how early on in those tires you gave him the data, but if they were new, might be good to connect one more time.

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[gerrylum]

@gerrylum has been quite busy testing things behind the scenes, so if your values aren't on that list, I'm sure he's just been too busy to get it updated just yet. I'm not sure how early on in those tires you gave him the data, but if they were new, might be good to connect one more time.

Thanks for the reminder. I've just added it. @narmstrong79 if you want to send me an updated route I can see if your values have changed at all.

 

[narmstrong79]

Thanks for the reminder. I've just added it. @narmstrong79 if you want to send me an updated route I can see if your values have changed at all.

Okay - here's another one. I had a good long one last weekend about 2+ hours each way but I can't get that to come up in my history any longer. Let me know if what other data I can provide to help grow this platform.

Share data: 4bed0fdfab06d7a4/0000002c--63c984101e/0

 

[gerrylum]

Okay - here's another one. I had a good long one last weekend about 2+ hours each way but I can't get that to come up in my history any longer. Let me know if what other data I can provide to help grow this platform.

Share data: 4bed0fdfab06d7a4/0000002c--63c984101e/0

You have these on your 22s, right?

 

[narmstrong79]

You have these on your 22s, right?

Yes.

 

[hgpayne]

So, turning ability for Rivian is highly dependent on the tires we've found. We currently use torque steering, so the ability to turn is limited by the lane keep assist torque controller. The stock Pirellis are the worst of the bunch for turning. Pretty much the harder the tire the better, but even then some soft winter tires do better than the Pirelli's. @gerrylum has a list here with their respective torque values if you care to look.

Optimizing Rivian Tire Selection for Best Openpilot Autosteering Performance · commaai/openpilot Wiki

I cared to look -- I looked -- still lost. See image -- I didn't change anything but I THINK mine by default was set to 2.5. From the link you shared it seems Michelin Defender LTX M/S2 21" should be around 2.2? Which of these twiddly bits should I be twiddling?

 

[gerrylum]

I cared to look -- I looked -- still lost. See image -- I didn't change anything but I THINK mine by default was set to 2.5. From the link you shared it seems Michelin Defender LTX M/S2 21" should be around 2.2? Which of these twiddly bits should I be twiddling?

That's a new setting, I haven't seen that before. Typically lateral acceleration factor is not something you "set" it's just a measurement of how much torque is being applied to turning and is different for different setups including tire selection tire size Etc.

I have to look into that setting but I don't think it's actually going to change steering performance.

In my opinion none of those settings need to be messed with.

 

[LivingInKaos]

I've played with the seeing and it didn't seem to have any affect for me.

 

[hgpayne]

That's a new setting, I haven't seen that before. Typically lateral acceleration factor is not something you "set" it's just a measurement of how much torque is being applied to turning and is different for different setups including tire selection tire size Etc.

I have to look into that setting but I don't think it's actually going to change steering performance.

In my opinion none of those settings need to be messed with.

Thank you. These are all under the "advanced' label, and I am at the opposite end of that spectrum. I really just want a plug and play system to get past the Rivian abandonment of gen1 ADAS. Certainly what I have now is better than stock Driver+. I just wonder if there's something I can do to make it better.

Here is an example of me NOT going around curves properly -- letting Sunnypilot (miss)handle the driving. . I do go through a set of curves where it does handle things nicely but after I turn onto Williamson Valley it gets a bit too curvy for Sunnypilot.

 

[gerrylum]

Okay - here's another one. I had a good long one last weekend about 2+ hours each way but I can't get that to come up in my history any longer. Let me know if what other data I can provide to help grow this platform.

Share data: 4bed0fdfab06d7a4/0000002c--63c984101e/0

No real change - looks like you're still getting around 2.2 m/s^2.

 

[narmstrong79]

No real change - looks like you're still getting around 2.2 m/s^2.

Thanks for the info.

 

[mizuno]

HI

@nick - thanks for the video. Cool to see the C4 in action.

I installed my comma 4 yesterday and per others the AXM connector is a pain but the rest not too bad. I have the longitudinal upgrade and fuse tap arriving Friday but sadly I'm leaving on a road trip tomorrow so that will have to wait.

I do have a couple of questions:

1) Comma Power - Comma state the power via OBD is optional and while this may be true in the general case I've read posts about potential issues with Rivians sourcing power from AXM and that ideally a fuse tap should be used. Now I see in Gerry's help doc that the harness should also be adapted to bypass the AXM power feed.

Does anyone have a sense of how common the reported Rivian issues are? Are they fixed with C4?
Given that I'm going on a long trip tomorrow and will be away for a few weeks should I hedge my bets and modify the harness and install the OBD power?

2) Is there a consensus about the best driver model for Rivian? I know this is somewhat driver specific. I have stage sunnypilot intalled and the default driver model currently. I've done a few drives and things work well overall but my car has overshot a couple of moderate speed / curves which was surprising.

Cheers
Mike

 

[gerrylum]

HI

@nick - thanks for the video. Cool to see the C4 in action.

I installed my comma 4 yesterday and per others the AXM connector is a pain but the rest not too bad. I have the longitudinal upgrade and fuse tap arriving Friday but sadly I'm leaving on a road trip tomorrow so that will have to wait.

I do have a couple of questions:

1) Comma Power - Comma state the power via OBD is optional and while this may be true in the general case I've read posts about potential issues with Rivians sourcing power from AXM and that ideally a fuse tap should be used. Now I see in Gerry's help doc that the harness should also be adapted to bypass the AXM power feed.

Does anyone have a sense of how common the reported Rivian issues are? Are they fixed with C4?
Given that I'm going on a long trip tomorrow and will be away for a few weeks should I hedge my bets and modify the harness and install the OBD power?

2) Is there a consensus about the best driver model for Rivian? I know this is somewhat driver specific. I have stage sunnypilot intalled and the default driver model currently. I've done a few drives and things work well overall but my car has overshot a couple of moderate speed / curves which was surprising.

Cheers
Mike

Great questions.

1) Comma power:
You’re right that Comma lists OBD power as optional, but on Rivians there have been a handful of cases where sourcing power through the AXM caused odd behavior due to back-feeding between power sources. It’s not extremely common, but it has happened enough that the community generally recommends modifying the harness to bypass the AXM power feed and using an alternate power source like OBD power or a fuse tap for the most reliable setup.

The issue isn’t really related to Comma 3 vs Comma 4. It’s more about how the power is sourced from the vehicle, so switching to a Comma 4 doesn’t inherently eliminate the possibility.

If everything is working fine right now, you’re probably okay to run it as-is for your trip. That said, it’s definitely easier to do the AXM bypass modification before installing the harness, rather than pulling everything apart later if you decide to do it down the road. The harness modification combined with alternate power (OBD or fuse tap) is more of a best-practice reliability improvement than something that absolutely has to be done before driving.


2) Driver model:
There isn’t really a single consensus “best” model for Rivian, but a couple that consistently perform well are:

• Down to Ride v6
• WMIv12

Both of those have excellent lateral control, which is the main thing you care about if you’re using the stock harness and relying on the Rivian’s built-in ACC.

If you’re seeing overshoot on curves, that can happen with some models depending on speed and road geometry. Trying one of those two models usually improves curve handling quite a bit. We’ve also seen that using an 8-degree wedge mount for the comma can help with curve performance in some vehicles by improving the camera’s viewing angle, so that’s another thing worth trying if you continue to notice overshooting.

Safe travels on your trip!

 

[LivingInKaos]

Thank you. These are all under the "advanced' label, and I am at the opposite end of that spectrum. I really just want a plug and play system to get past the Rivian abandonment of gen1 ADAS. Certainly what I have now is better than stock Driver+. I just wonder if there's something I can do to make it better.

Here is an example of me NOT going around curves properly -- letting Sunnypilot (miss)handle the driving. . I do go through a set of curves where it does handle things nicely but after I turn onto Williamson Valley it gets a bit too curvy for Sunnypilot.

The Comma on Rivian currently uses the Lane Keep Assist system which is bound by the torque steering controller. It is limited in it's ability to turn with the torque it has available. So when you get to the tighter turns, it just can't turn the wheel enough - one way to mitigate a good portion of that is with your tires. The stock Pirelli's perform the worst. Harder tires tend to do better because it doesn't take as much torque to turn them. @gerrylum has a tire guide HERE.

As for the speed control on Sunnypilot using the smart cruise control (map or vision) - you have to have the longitudinal adapter from Lukas (XNOR) in order for the comma to control speed at all.

 

[mizuno]

Great questions.

1) Comma power:
You’re right that Comma lists OBD power as optional, but on Rivians there have been a handful of cases where sourcing power through the AXM caused odd behavior due to back-feeding between power sources. It’s not extremely common, but it has happened enough that the community generally recommends modifying the harness to bypass the AXM power feed and using an alternate power source like OBD power or a fuse tap for the most reliable setup.

The issue isn’t really related to Comma 3 vs Comma 4. It’s more about how the power is sourced from the vehicle, so switching to a Comma 4 doesn’t inherently eliminate the possibility.

If everything is working fine right now, you’re probably okay to run it as-is for your trip. That said, it’s definitely easier to do the AXM bypass modification before installing the harness, rather than pulling everything apart later if you decide to do it down the road. The harness modification combined with alternate power (OBD or fuse tap) is more of a best-practice reliability improvement than something that absolutely has to be done before driving.


2) Driver model:
There isn’t really a single consensus “best” model for Rivian, but a couple that consistently perform well are:

• Down to Ride v6
• WMIv12

Both of those have excellent lateral control, which is the main thing you care about if you’re using the stock harness and relying on the Rivian’s built-in ACC.

If you’re seeing overshoot on curves, that can happen with some models depending on speed and road geometry. Trying one of those two models usually improves curve handling quite a bit. We’ve also seen that using an 8-degree wedge mount for the comma can help with curve performance in some vehicles by improving the camera’s viewing angle, so that’s another thing worth trying if you continue to notice overshooting.

Safe travels on your trip!

Thanks Gerry.

I'm not having issues right now but if I have time today I might try and adapt the harness.

I really don't want to take that connector out of the AXM There's not a lot of slack on the harness but hopefully I can get enough purchase to remove the power pins.

I'll have a play with the models you suggested.

While I'm here - I had an interesting exchange with Lukas about the Long Upgrade. There was a problem with my order, anyway, I was asking him about power options for that module as the Janka Hub Box solution is not currently available. He stated that the module needs to be connected to the secondary usb port but only initially for set up. After that it can be powered by a regular USBC power feed which could be done as another fuse tap. I'd rather not run 2 wires up to the mirror so thought that was an interesting option.

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