Digging Deeper on Tesla's Etherloop Wiring System
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- Опубликовано: 1 июл 2024
- Time for a deep dive on Tesla's EtherLoop, which is the final critical innovation needed for the unboxed manufacturing process. Tesla is moving from specialized hardware controllers to generalized and software defined controllers and linking them with Ethernet - and it's over 10 years in the making.
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Timeline
00:00 Introduction
01:30 Automotive Electrical Systems 101
03:34 The Evolution of Tesla’s Automotive Electrical Systems
08:02 The Importance of Insourcing Electronics Design
09:23 EtherLoop // What is it?
14:45 EtherLoop is HARD
16:46 The Cybertruck is a Mongrel
18:19 EtherLoop // Other Benefits
19:43 Summary
Intro Music by Dyalla: Homer Said 
Наука
Now I'm starting to understand what Elon meant with: "don't follow meaningless standards!"
Oddly, this is all based on a 2020 standard, sponsored by Ford and Audi
Stockton Rush said the same thing.
@@Dularr maybe bad marketing from Ford and Audi kkkk
@@marceloniendicker8335 more likely they are slow and unwilling to change
Isn't that what The Ocean gate guy said to
20:45 -> This should be Tesla's slogan. "Making the impossible merely late" xD
🤣🎯
It's essentially Musk's slogan and doesn't apply only to Tesla.
@@celeron55 Project management triangle, "Time, Quality, Cost - pick two". Elon is trading time for better quality and reduce cost.
How about "We at Tesla eliminate the "stupid" no one else was willing to" Ok, that's harsh. Try again. "We at Tesla design for the future" Ok, maybe that's a bit better.
I prefer “your requirements are stupid”.
Great explanation of CANBUS vs EtherLoop. Citing and including the visualization of both was quite helpful too. Thanks!
You're most welcome man!
Minor clarifications: The Ether part means it will be a different industry standard than CAN, not a complete invention reinvention of the network layers. They will probably be using IP4, to have open source components work right away. The local area network in private homes are typically a star or a tree, but that is not failure tolerant. Any component can be offline with a single point of failure. The Loop-part of the name is a reference that it is a loop-architecture, not a bus. That means if you cut the network, the packages will take the other way around the network. Like TokenRing. It is a fault tolerant network. Each zonal controller will effectively have a small router. It will be interesting to see which OSI layer they create the “loop” in: actual loop, or virtual, but loop-like.
Probably they won't be using IP for time sensitive / safety critical parts like brakes. But there are related ethernet standards for that, see "Time Sensitive Networking" which is about making ethernet usable for real-time workloads.
I suppose it might be possible to run less critical workloads like entertainment over IP using the same wires as the real-time stuff, just at a lower priority.
Is there a MTU size published somewhere?
I'm pretty sure they have said it's ethernet physically but it does not communicate with IP and you do not need IPv4 for that, IP is layer 3 and you only really need layer 2 to have communication.
Ethernet must be loop-free. Though modern switches can detect loops and deactivate those ports.
Aren't all the issues around packet collision introducing latency addressed by QOS tagging?
Slogan of the Navy CB’s “The difficult we do immediately, the impossible a little longer.”
Thank you. I knew it sounded familiar. Like several of the phrases Elon likes to use, he didn't come up with them, he's quoting phrases long used by engineers, e.g. "the best part is no part." He doesn't claim originality but his high profile introduces the phrases to non-engineers.
this is also the lyrics to Billie Holiday's 'Crazy He Calls Me' "The difficult I'll do right now, The impossible will take a little while"
This is by far the best video I have seen on the subject of 48v, Etherloop technologies and comparing it to CAN. This was phenomenal. The graphs showing ownership of controllers across time- EVERYTHING.
Subscribed.
😊 Really happy to hear it!
Excellent educational session, thank you. One of the images shows a highly significant change essential to Ethernet is replacing legacy individual wires with ribbon cables. 48V from 12V makes this significant improvement possible. While ribbon cables are not new, their use in automotive is. Improvements include, automated manufacturing, Electromagnetic Compatibility/Immunity (EMC/EMI), wire-to-wire coupling. Providing total control of which wire is next to which wire, eliminating splices, twisting wires, the list goes on and on. Not to mention sharing controllers between vehicle models, without having to engineer new connectors, simply cut longer or shorter ribbon cables. Thanks
Thanks for the comment and the insight! Much appreciated!
Isn't noise cancelling an issue without twisted pair going on like in Ethernet cables?
Power to motors would still have to carry lots of current.
Great explanation. I did a presentation at the Automotive Ethernet Congress last year about unraveling the 10BASE-T1S wiring harness, so this fits into the main area I am working on 👍😅 I wasn’t familiar with the latest Tesla architecture. Many OEMs are still struggling with zonal architecture. Keep up the good work and greeting from Bavaria.
Awesome! Glad you enjoyed the video 🤠✊🏼
And thanks for the comment! It's always good to hear from people in the industry to let me know if saying stupid things, lol
@@thelimitingfactor No all good. For the aggregated links between the zonal controllers 10G is ready and 25G is on its way. We tested also with 50G is possible over 5 m in case anybody needs it and glass fiber may be an option in future. I am im RnD try to keep an eye on trends and what may be of use in future. Tesla is quicker than the rest of the market.
I wanted to add that Ethernet collisions were mitigated over 40 yrs ago in commercial networks. Software defined routers and switches are mature and can be added to any of those generic car controllers. Growing up with Ethernet speed increases, lots of people do not realize that protocol stack bugs show up as speed increases. The CANBUS being so slow, I am sure there will be many failures nobody ever dreamed of when bus speeds are increased. Point is that Ethernet has been through the gauntlet for over 50 yrs and there is just nothing close to its robustness. Ethernet wiring EMI is very well understood since it is just about anywhere. One can also run multiple networks on the same wire e.g. one encrypted and another not encrypted. I am just touching on the tip of the iceberg on Ethernet's benefits over any other communication protocol.
Used to live and always loved Rheinland-Pfalz and Bavaria .. and the seasons' changes there. You should arrange for a visit to the Giga-Berlin plant to tour and talk with some of their auto-electric engineers. I bet you would enjoy that and could make it part of your next paper at AEC!
Totally agree. They're talking about t1s instead of can, but the major controllers still use 100/1G-base-t1. What i expect they dropped is autosar. That's sh*t's stupidity incarnate.
I want to see Giga Mexico being built to manufacture unboxed $25k EV boxes with all the latest and greatest Tesla tech.
It expect to see that, or something very close. The lateness of Cybertruck and the long wait for the 25K car seems to be partly attributable to Tesla reinventing how a vehicle is wired and thus manufactured. It's not about two vehicles, it's about transforming how any vehicle is made.
@@donjones4719I keep thinking it’s also the difficulties they have run into on the 4680 battery. They really advertised the plan to get vehicle cost out through internal manufacturing and a 60% (~) reduction in cost from that (as I recall the battery presentation)
Wikipedia definition of etherloop
"etherloop" have been developed, including use for automotive intra-vehicle communication in the 2020s, where a gigabit Ethernet physical network has been used with a proprietary time-sliced, network protocol for near real-time, redundant control and feedback of motor vehicle subsystems."
I think you missed the loop aspect of Etherloop. A typical Ethernet or CANBus network only has a single path from source to destination. The topology that you’ve drawn shows a loop whereby controllers on the network are aranged in a loop whereby messages may be passed clockwise or counterclockwise around the loop.
This allows for fault tolerance in the event that the ring is broken either due to a wiring fault or a failed controller. This is important in eliminating single points of fault.
Nope, he covered that as well.
"Tesla - Making the impossible - Merely late".. What a great line! Thankx, I'll use it often..
Your depiction of Ethernet is based on very old implementations. Back in the days of 10/100mb Ethernet half-duplex was a popular option to allow you to put multiple devices on two wires. You needed to implement the collision detection and avoidance protocols to minimize/eliminate collisions. This introduced an unpredictable jitter that was often unacceptable in hard realtime systems such as controllers.
More modern Ethernet is full-duplex and each endpoint is directly connected to a network switch. This eliminates the collision issue and most of the jitter. Now when two signals arrive at the switch at the same time one will be sent out ahead of the other. There are protocols that you alluded to make simultaneous messages more deterministic.
Good point! A few other people have made the same comment
For low bandwidth 10Mbit/s there is a standard defined which enables also bus topologies. It's called 10BaseT1 in different variants . Used in automotive and industrial control systems
This is the difference - in the switched scenario they won't have collisions and retransmissions even at high levels of utilization (at a cost of store and forward on a switch which used to be expensive but is now dirt cheap!) but every node has to be wired to the switch. That is what they are trying to avoid. Lots of long wires (even if small.) They are using a bus/token setup so they can guarantee delivery of the necessary data at high speed and low latency but also avoid all the wires.
Great video. I am reminded of the old Lexus slogan, "The relentless pursuit of perfection." It may have been only a marketing gimmick for Toyota, but it's the way of life for Tesla.
How it relates to Lexus UX300e? 😂
It wasn't only a marketing gimmick for Toyota. But people are doing it even better now, making Toyota look bad in comparison. And Toyota may have fallen back from their good habits during the years.
You obviously have never worked for Tesla. I think a better term would be "The relentless pursuit of cutting vehicle costs".
Thanks as always for your amazing, no fluff, detailed, insightful, interesting, well researched (and a bunch of other positive adjectives) videos. Jordan you're a true gem for the Tesla community.
✊🤠
A loop type networking was used years before the current style of ethernet networking came out. It was called Token Ring. If there was an 'end' to the loop that was not connected back to the loop a 'terminator' was needed on the end of the loop (basically a specific small resistor to keep down 'ringing' similar to water hammer absorbers). The loop protocol required a token be passed between each device to say whos turn it was to talk next, everyone being allowed a 'slot'. If the token got lost the 'controller' would restart the token on the wire. Ethernet designed for everyone to listen and talk whenever someone else wasn't talking if needed, was a overall speed improvement on a 'quiet' network, but was slower on a network with a lot of traffic, assuming each ran at the same frequencies. Yep, loops have been around a long time, and they can also be great for redundancy (traffic can flow either way around loops, not just one direction), so if it is cut somewhere, the loop can detect that and even where, but still keep functioning, of course depending on the equipment sophistication. So endeth todays history lesson from an old grey haired geek.
Ethernet also needed terminators… as did SCSI and does PCI. It is an electric thing to dampen reflected waves. Token Ring originally depended on a ring for passing around the token that allowed a station to transmit. The wires didn’t go all around the ring but were station-to-station. There was a method for detecting token loss, duplicated tokens, and for regenerating a single token if necessary but it was a bit slow.
Those were the days!! 👍
(Old gits of the world unite!!)
I love insights like this! Thanks for the comments!
what you are describing is not a ring archtecture (two endpoints per wire), but a traditional bus with many endpoints using the same wire. The "token ring" is just a popular system for determining whose endpoint's turn it is to speak next.
The "Token Ring" is architecturally more similar to CANBus than to a ring. (shard wire across all devices to transmit data)
The Term Token Ring is just the "sofware part" to decide who can speak. basically a Token is passed around on a bus, and whoever currently has the token can talk, everyone else listens. the ring is because it is passed around, it does not refer to how the devices are connected.
I have been waiting for someone to expound on the implications of the ether loop. I set up one of the first industrial Ethernet networks in Canada in the early 80’s. Glad to see someone like Musk push this technology to its logical conclusion in autos.
Tesla's CAN systems actually already use location-defined general purpose controllers to an extent. It's part of what they've been doing since the beginning.
Etherloop seems to be a great idea. Imagine using 20 times less wires with that new design. Thanks for the visual explanations. Great work, your speculation is probably right.
Sure thing! 🤠🙌🏼
19:35
"Universal controller design".
.
This has more implications beyond the "front end" supply chain.
Parts inventory.
It's a huge reduction in parts warehouse inventory/storage (ask Farzad!).
Also, Service.
Speaking as a Field Service Rep in another industry, vehicle space is limited.
Any time I can carry 1 common part for multiple devices it's a win.
.
Then there's faultfinding.
If you have that "odd" intermittent, elusive fault, or simply don't have a replacement to hand, you could swap 2 controllers and see if the fault moves with one of the units.
Amen!!!
I was very interested on the Tesla 48V system and how they 'solved the CAN-Bus'. It came as a total surprise having such an explanation from you as I did not expect. A good starter for a very important subject. Going down to all details will require much more time and explanations. Up to now there is very little.
😁 Yes, I didn't expect it either, lol. I'm sure there are people better positioned to explain it, but I wasn't satisfied with any of the video I saw. And totally! There's a lot more to it than I showed here.
For anyone that's worked on networks it's a "Welcome to the 21st century" moment.
To be clear, a "48 volt controller" means it's POWERED by 48 volts, the data / signalling is a much lower voltage. Probably carries power POE style at 48 volts throughout the loop.
A veritable cornucopia of delightful information. Many thanks for your contribution. You are both informative and generous.
😊 You're most welcome!
Amazing video. Impressive what Tesla is doing to always keep innovating
🤠🤜🏼🤛🏼
The real issue is that lots of those cross car systems are safety critical. Braking system, lights, around car sensor packages for the various levels of self-driving and so on. Having a single approved and well tested system handling each one that you can pretty much get off the shelf is very convenient.
Ensuring something like the ABS system under emergency braking is acting in a coordinated way at the millisecond timescales required on all 4 corners of the car is much easier with a single module handling it all.
That's where the EtherCAT standard helps. Each device modifies the Ethernet packet as it travels both ways around a ring. The result is a high bandwidth low latency communications with redundancy.
Convenient or complacent? This is why traditional OEMs are failing behind.
@@GregHassler They really aren't.
ABS master control will still be a single module, but it will source and send data to each brake over the network in its time slice. If/when they switch to the Brembo Sensify system this network can eliminate the hydraulic system completely (or partially, there's options there too.)
Professional, informative, and well done!!
✊🏼🤠
The video I've been hoping for. Thank you!!
Great episode! Thanks!
Totally agree, the EtherLoop is THE innovation. It shapes the future interface for all electrical components in the car, which is a large number. Over time it will reduce the hardware costs and also reduce software maintenance and development costs.
I wonder if their custom deconfliction is based on standard network QoS architecture for VoIP and stuff
You don't know what it really is so you can't really make such bold claims about it. The next innovation may make it obsolete.
Thanks for another well organized, easy to understand video!
great presentation. Thank you for completely explaining through to the production advantage.
This deserves a deeper dive.
Sounds like they just took modern computer networking and stuck it in a car. Computer networking already supports all the functionality you described including delivery of power at 48v to endpoints.
The Cybertruck is basically doing for the next gen platform what the Model 3 did for the Model Y.
🎯
@@thelimitingfactor
I *think* we might see this in the "Cheap interim" vehicle.
Model 3 (Y?)
Assembled *exactly* as per the presentation shown.
By necessity having the new systems in place.
.
Amortised body parts/ castings, testbed for 48v/ Small vehicle steer by wire/ Electric braking(?).
Small pack.
Single motor.
"Dialed back" performance (focus on range)
.
Target price? $30k (ish)
.
Sold as "cheap Tesla for drivers"
(Goodbye Corolla?)
It is amazing how Musk can move in a different direction from all others with such confidence. The cyber truck changes everything. And his drive and confidence affects all those that work on these major projects. And he has the time and energy to produce twelve children. I hope he does well for a very long time. Our country needs him.
48v, etherloop and distributed custom controllers are going to a massive gain in efficiency, cost, weight, reliability.
The reduction in wire, connectors, controllers and PCB will save a lot of money to Tesla
This was incredibly informative. Thank you for the excellent Content.
It's another "Industrial Ethernet", the "Loop" reminds me of EtherCat which - from what I've heard - is state of the art. They could have adopted TSN (time sensitive networking) and try to push it but seems like tesla tries avoiding industrial standards whenever possible. A really risky move, if this architecture has just a minor design flaw this could lead to many controller/networking failures and thus crashes.
Great information. Thanks!
Presumably this is going to be in everything Tesla produces in the future. I imagine the need for this in the Unboxed production process, is that you need a simple way to connect each of the pre-wired regions together without having to install a loom after the parts have been assembled.
I suppose the controllers could be identical for each corner of the vehicle, and for every vehicle that Tesla makes. There's a huge economy of scale using that approach.
Maybe they were inspired by Avionics Full-Duplex Switched Ethernet from Airbus or EtherCAT ? You can prioritise frames and loose some cable in the loop.
And they probably use the same "flyby" packet modification and the name "loop" implies they are using the same redundant ring design.
Terrific video.
It would be great to see the tare down of the next gen vehicle, you and Munroe collaborating. This would replace the conceptual with actual and be fascinating.
Thanks for your amazing work
Thank you so much for this video . Great insights .
Fantastic vid Jordan!! I never could really wrap my head around Tesla’s ideas here, now I understand much more of it
Really happy to hear it! I saw a lot of people covering it, but there was so much missing information that it didn't make sense for me either. So, I made the video that I wanted to see 😁
I think this technology fits in with collision repair. As the unboxed assembly process brings various sections of the car together at the end of the assembly line, this implies that whole sections of the car could be later replaced.
I’m also speculating that each section of the car could have its own gigacasting.
Gosh I love that intro. Have to play it twice.
Etherloop sounds like an industrial network protocol like EtherCAT, Profinet, or Ethernet/IP. There are many chips out there that support these industrial protocols. All are time-sliced for reliability and consistency.
IMO, this was your best and most interesting video.
Hey thanks man! I appreciate that.
They may have taken inspiration from Ethercat, which involves each device adding its data into a 'frame' that gets sent around the loop at regular intervals (~4KHz) rather than individual devices messaging one another
Fantastic as always jordan! Infinitely informative to get the color on this iterative process that Tesla lives in
IIRC Elon mentioned the Ethernet works a bit like token ring to provide consistent latency
In the early days of ethernet, it was a shared broadcast medium and we got a lot of collisions and retransmissions. Tracking collisions was a necessary job for network admins to know when your network was going to collapse, and you had to partition it. But in the 90s, we moved to switched ethernet, and collisions are a thing of the past. Ethernet switches are dirt-cheap, a few cents. I would be shocked if etherloop went back to using broadcast over a simple switched fabric.
Thanks for the insight!
Awesome video Jordan, thank you!!
🤠✊
The key innovation here ISNT etherloop, it's the distributed generalised controller architecture. Enabled by Tesla's vertical integration inhouse electronics team.
There's nothing stopping this from being implemented on canbus. 3D printers do that now, the main controller talks to the tool head that controls endstops, heaters and thermocouples etc.
You can also daisy chain canbus by simply putting an input and output port on each device with an internal bridge and optional termination. That will enable the unboxed assembly. It's done the same way on CNC machines.
The only plus is the datarate as mentioned. Sure you can't pipe AV over canbus but if you're just focused on the manufacturing benefits covered, it's the distributed architecture that's the main innovation
Great video as usual!
Awesome breakdown! Thanks!
Thanks Jordan. A next logical step would be to eliminate the network wiring completely. This can be done in at least two different ways: 1) Provide only a 'ring main' power loop and send and receive serial data down it at gigabit speeds. 2) Use the same main power loop and send only failsafe signals down it (emergency braking, steering, horn for example) but send all other data wirelessly.
Alternatively to a ring main, which provides two routes for all currents, and perhaps at the expense of needing more wiring and having only one route for current, a main power bus plus spurs to each corner system could be used.
👍👍 great video.
Ethernet & POE (power over Ethernet)works on computers.
It will work in cars.
Yes , it is called PoDL Power Over DateLine. Automotive Ethernet uses only two wires therefore it looks a little bit different than PoE in detail
Excellent! Thanks so much!
Great content. Thank you.
Loved this. Thanks 🙏🏽
Good video, but they wouldn't pass uncompressed video from even a single camera over Etherloop as even a basic 2MP camera generates over 1.4Gbps at just 30fps. Now they could be using Ethernet cameras (which perform H.264/5 compression at the camera), but that introduces at least 2 frames of latency which wouldn't be acceptable for self driving, so my guess is that they'll continue to use something like GMSL for the video feed to the FSD computer and then perhaps forward a compressed stream of the rear and sideview cameras over the Etherloop bus so that it can be consumed by services such as the primary display.
God I love these comments. Super smart bunch today. Lots of great insights
Currently automotive cameras use "serdes" , like FPD-link or GMSL . Automotive Ethernet is currently being standardized to support also speeds up to 25Gbit/s. And in future even more .Currently video data is not compressed because lossless compression does not work well with certain safety measures. Typical speeds are currently 3-8 GBit/s .
Thank you. Well done.
As someone who understands a thing or two about this video, you are bang on target.
That's great to hear! I've had some very mixed responses. 😁
10+ - I have been dying for an episode like this. More more more
😊✊
Great video. It becomes even more clear how Tesla is out pacing the competition.
Brilliant! Thank you!
Excellent video.
Thank you!
One benefit of the Etherloop that wasn't mentioned is it's a network which means the signal has more than one possible wiring route - If there's a problem with a specific cable there's a back-up route that'd still transmit the signal (there's no single point of failure (when it comes to wiring)
Layer 3 switched devices resolves Ethernet collisions. Layer 2 hubs, we're collisions can occur is a thing of the past not used nowadays.
Canbus was great, 40 years ago. Now it is a niche protocol used due to inertia. Nobody I know likes using it, except it really is "job security". Using 48v and a software stack everyone is experienced with is overdue. There is no reason why data can't be transmitted over the power line as well, essentially making your fuse block a network switch. Since Tesla is doing everything in house, realistically they are the ones who can make the leap/change.
Great video!!!
Excellent, thanks
"Etherloop" sounds like the "Modbus" (RS-485) system I worked with.
It can connect all the element in 2 wires because each module has its own unique name; in the software section,
the program can call each element to get the data or command it to execute something.
A similar thing happens with CAN, but ethernet is so much faster per twisted pair. I'm not sure if there's a technical reason except that the signalling on CAN bus must be collision free (so the higher priority message will always get through and the lower priority message stops transmitting), where with ethernet it's just retransmitted as he laid out in this video.
@@ThisRandomUsername id had to be ethernet becouse they have to transmit the video to the computer and audio to the speakers
Yes, it sounds like Modbus which I worked on while working at Modicon, a leader in programmable controllers.
@@johnpoldo8817 I use "Advantech's" hardware (ADAM series), the computer language is "Python" and the OS is "Linux".
@@ThisRandomUsername this is actually outdated info, since it refers to how ethernet works when you use Ethernet hubs to connect multiple devices. There are not even hubs available for Gigabit Ethernet, and even for the lower speeds Hubs have been replaced entirely by Switches more than a decade ago, possibly even two decades.
Switches essentially make a mini ethernet link for every port, and forward data to the port where its supposed to go, and if that port is currently transmitting they cache the data and send it after the port is done transmitting.
compare that to the ethernet that was wired with hubs that were much stupider devices: a hub would just repeat what it received on any port to every port, without doing any managment (which was why collisions were possible)
Thank you...
Excellent video. I'm writing a report on that topic and 100% agree with everything said. I know some Chinese OEMs are also deploying zonal architecture, but I'm not sure if those are interconnected via an Ethernet backbone. By the way, you forgot to mention "TSN" (Time Sensitive Networking), a key technology to make Automotive ethernet deterministic and suitable for safety-critical applications
Aerospace has done critical Ethernet bases for a while (ARINC 664, AFDX, etc.). Tesla just needs to look at how it's been done there.
I found interesting that so many peoples don't seem to have a clue about the AFDX success in avionic since more than two decades already.
As others pointed out, the protocol can be applied regardless of the hardware. On the ethernet network it can still use a seudo-can protocol which prioritizes messages opposite to the home ethernet systems
Nicely done, Jordan.
I am sure some felt this was the battery education and analysis channel, due to all the battery related content, but it is so crucial I totally understand why you would be cranking out so content much on that topic.
Loved seeing this video because it is another piece of the Ezv puzzle.
If you are not already, I hope you deep dive EV tires, both traditional and airless tires. It is amazing the impact tires have on range and ride quality.
Keep up the great work.
The ether loop and the 48V architecture are part of the same strategy. Many systems will be powered over the Data cables ( power over IP) the data cable will be able to develier around 100W of power using just the Data cable it self. ( The modules them selves and possibly even some end points will be powered from the network and the modules.
Awesome video Jordan. It just shows how Tesla is innovating ant non stop basis. It was very interesting to see how connectors were changed on 48V architectures. Much cheaper to make and easier to isolate from water ingress i believe.
Today's HSCAN is mostly 500kbps but the protocol can support up to 1Mbps but is rarely used. CANFD can support much higher speeds up to 8Mbps
CAN devices do not all have to be on the same bus. There can be multiple bus with a controller bridging communication. In general, only those devices that need to talk to each other will be on the same bus. You don't want a shorted bus taking out everything. Also, traditional vehicles do not have a pile of different controllers in different locations. They use a few large controllers with lots and lots of thick gauge wires going from those controllers to the various different devices / sensors. But this has more to do with fusing then with the communication bus. Remember, traditional vehicles have mechanical fuses mostly located in one place. Reductions in wiring will require distribution of fuses which in turn requires use of eFuses (electronic fuse) in place of regular fuses. These eFuses will each require a controller and all controllers will have to be connected together via a communication bus. But this allows you to replace a large number of cables with a single 48V power line. So great, but it has nothing to do with the communication bus used. It does require a lot of work on the user interface to allow for the management of the eFuses. No more going to the fuse box when something stops working. The UI has to report the error, reset the fuse either manually or automatically, etc. Lots of design work required but the hardware is actually reasonably simple.
Great video!! Brilliant Tesla!
Want to bring a safety perspective. Although the ring ethernet can bring redundancy when one of the ethernet cable is damaged, the signal can go from other routes (similar to iso-spi daisy chain), the Etherloop requires a higher safety level and complexity level of each controller (ASIL-D as must I believe). As example, for the existing CAN topology, if the brake controller malfunctions, at least the vehicle still has steering, light and other functionality. For zonal topology, even if one of the four controller malfunctions, it basically lose ALL vehicle functions since most of the feature requires 4 controllers to coordinate together. There has to be redundancy implemented on controller level to trade-off the redundancy from multiple controller in traditional topology
One of the other reasons to move to 48v would be prep for moving to ethernet, as they can then easily use POE to deliver power to the controllers.
A very important point that this otherwise excellent video has missed (and commenters too) is that with generic controllers close to the hardware, many more endpoints, both sensors and controllers, can be implemented without massive amounts of wiring.
This allows localised control, such as suspension sensing and feedback to be under software control which in turn means software defined hardware (which you touched on). The important upshot of all this is that Tesla can (and does) use software updates to refine how the entire vehicle behaves, right down to stuff like traction control, anti-lock braking, configurable suspension, and much much more. Levers, rods, springs, cams replaced by software.
This in turn makes recalls and improvements mere downloadable updates, saving time, money, and allowing Tesla to make their vehicles better on the fly without owners having to do anything except accept the update and smile a lot. Their grand design is pure engineering beauty and well ... downright sensible.
Thanks for the well-considered comment!
one note, increasing the data rate does wonders for reducing latency.
if you compare the highest speed canbus (0.05 - 1Mb/s) with gigabit ethernet, you have 1000x-20,000x the bandwidth. At some point, this increased speed means that even the retry oriented nature of normal ethernet will get the message through faster than the canbus would
I''m sure they created etherloop because CANBUS doesn't have enough bandwidth to integrate AI and video demands the controllers need to do their work.
The range of things you can make me understand is amazing. Your explanations are so clear and are presented in a sequence that builds on each previous step. The latter should be a no-brainer for any exposition but is too frequently not attained. I'm sure that takes a lot of work.
Ha! You just described exactly my philosophy when I'm writing. Sequencing! Yeah, I find so much information out there is put together in a sloppy way. It's aggravating. But, maybe I'm just a bit too much on the spectrum, lol
@@thelimitingfactor I think you're in just the right spectrum sweet spot. Well, for this at least. Some other things aren't so easy for us folks.
Typically a remote expansion IO unit connect one corner stuff, where master central unit processes the data statuses, measurements and commands. It is only possible for Proprietary OEM architecture. If you take for example commercial transport electronic braking system from a supplier like ZF, you may have it as standalone system interconnected as subsystem and communicating with other systems by J1939 Network CAN.
Brilliant Jordan. don't know what I'm more impressed with, Tesla's know-how or your reverse engineering.
Thanks!
You're most welcome! And thanks for the support 🔥
Model railroads' DCC control system is the same as Tesla's Ether Loop System - identical in design and implementation. Neither requires a closed loop. Data is PULSED out to a train car, engine or trackside accessory. That device completes the operation and returns a "device mode changed" signal. Many trains and devices are controlled with one controller and TWO DC wires - INDIVIDUALLY - with variable pulses.
I'm familiar with CAN and ethernet wirings & protocols, as well as other HW protocols used in high-speed, high-data rate computers.
As you were describing the system & problem i had a few thoughts.
1) why tie power & comm on the same network?
The batteries, plug charger or regeneration from braking all generate power. Access points to any power is perhaps the shortest line of all as the battery pack practically stretches the entire vehicle base. Certainly there are multiple power access points in this system.
Imagine a short power hop from any corner to any nearest access point. Saves LOT of wire weight. Let each device pull whatever volts it needs. Independent of any standards.
2) comm doesn't require heavy wires. It can be done with much lighter fiber optic strands (any one of wich supports thousands of non-interfering comm lines between any controllers.light does not interfere in many ways.
Run a single fiber loop around the entire veh and thats it.
Thanks for the great video. One correction: modern cars, including Teslas, have multiple CAN busses.
I provided the insight that has led to the CyberTruck wiring harness. I suggested 1 power circuit and signaling on that power circuit to turn things on and off. The noise on the power circuit prevented effective communication, so they went to Ethernet.
Nobody did it before because they weren't smart enough to think of it, huh?
16:41 with a true ring architecture, there isn't even a need for a new bus access arbitration scheme.
You only have two endpoints per bus. If you use bi-directional wiring (extremely common with ethernet), both can send and receive at the same time, you will never get any collisions at all. The endpoints just need to prioritize which messages to relay/send first.
I believe this is also a two wire solution. With one wire having a hier priority. So braking can be sent through one wire and the entertainment sent through the second wire.
got it : general purpose controllers on each autonomously built chunk in the unboxed process.