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Where is this extra mile of wire going? Surely they didn't just put a bunch of extra wires in the harness for no reason. Were the extra wires a relic of an earl

Where is this extra mile of wire going? Surely they didn't just put a bunch of extra wires in the harness for no reason. Were the extra wires a relic of an earlier stage in the design process?

klyrs 4y ago
The article says that the wiring harness is longer than it needs to be. My guess would be that there are several hundred wires in the harness, each signal paired with a ground, so an extra few feet (an extra fraction of an inch per mounting point?) would really add up. That extra length might make it easier for the installers to wrangle; efficient design often comes at cost. Edit: and, come to think of it, this is a Steiner Tree problem with some very interesting constraints. Optimizing very large instances like this is a Hard Problem. Even if everything is locally optimal (unlike my hypothesis above), it can still be far from globally optimal. Recomputing a solution, spending longer on the computation, can make a big difference!
- schiffern 4y ago
  The comments come about 48 minutes in on Ford's quarterly conference call.[0] When they talk about "length" they are adding up the length of all the individual wires inside the harness. So it can be any combination of: • a bundle is too long • a bundle contains more wires than necessary (eg switch to a shared power and data bus) • a bundle is completely unnecessary (sometimes separate modules can be combined/eliminated) • in some rare instances, wireless data transmission can be used • ultimately, switching from 12 V to medium-voltage (48-54 V) can eliminate multiple wires needed for high power modules. [0] https://youtu.be/XDtE-Stzol8 https://youtu.be/XDtE-Stzol8
fsociety 4y ago
Wiring is a very hard problem in vehicles. It’s why you see physical switches being switched out for a touchscreen, and some of the tech the big automakers are most excited for are, at the end of the day, just to reduce the amount of wiring required for each car.
- anaganisk 4y ago
  If we are doing bad trade-offs, let's run like flintstone cars instead of an engine. It does sure take up a lot of space and is very heavy.
- foepys 4y ago
  Switches in cars don't directly connect to the thing they control. They haven't for decades now. [1] The connector of a touchscreen and a unit full of switches can be exactly the same. 1: https://en.wikipedia.org/wiki/CAN_bus https://en.wikipedia.org/wiki/CAN_bus
  - wiml 4y ago
    Or, for that matter, https://en.wikipedia.org/wiki/Local_Interconnect_Network https://en.wikipedia.org/wiki/Local_Interconnect_Network
jmoak3 4y ago
To add to the other replies - the networking configuration of the car plays a huge role as well! Is it CAN bus? Is it Ethernet? Is it a mix? How many computers are in it? How are they connected? Have you centralized the microcontrollers to some degree? What about connections between microcontrollers? Just like microservice oriented architectures and monoliths, you may choose the form of your destroyer, and an extraordinarily well-connected topology with no centralized points to bounce between can lead to ass loads of wires :) I'm convinced of the quality of Tesla's internal networking - I don't have concrete data on this but the capabilities they showed in 2018 such as over-the-air updates told me they had to be more sane than their competitors. To be able to update any part of the car like that I'd imagine they centralized a TON of the random bits and bobs into a few Ethernet connected machines even back then. On top of that, the rumors of the telemetry they collect is the stuff of legend! The problem with a lot of these car companies is that they're a little behind the tech curve. I left automotive in 2018 so I may be old news here but in-house out-sourced was still a large debate when it came to the design of such systems. It will take a while for them to bubble up leadership with relevant experience to make the right calls - maybe with the layoffs at big tech co's it'll happen sooner than later? Automotive companies I interacted with in 2018 definitely knew then what they wanted, the hard part was finding the right people to deliver and manage.
- satiric 4y ago
  I understand that there's gonna be a lot of wiring, having done a lot of vehicle wiring myself. What I don't understand is how they ended up with so much more wire than necessary. Is it from putting wires in the harness that didn't actually need to be there, or is it from routing the harness in a suboptimal way?

Where is this extra mile of wire going? Surely they didn't just put a bunch of extra wires in the harness for no reason. Were the extra wires a relic of an earlier stage in the design process?

klyrs 4y ago

The article says that the wiring harness is longer than it needs to be. My guess would be that there are several hundred wires in the harness, each signal paired with a ground, so an extra few feet (an extra fraction of an inch per mounting point?) would really add up. That extra length might make it easier for the installers to wrangle; efficient design often comes at cost. Edit: and, come to think of it, this is a Steiner Tree problem with some very interesting constraints. Optimizing very large instances like this is a Hard Problem. Even if everything is locally optimal (unlike my hypothesis above), it can still be far from globally optimal. Recomputing a solution, spending longer on the computation, can make a big difference!

schiffern 4y ago
The comments come about 48 minutes in on Ford's quarterly conference call.[0] When they talk about "length" they are adding up the length of all the individual wires inside the harness. So it can be any combination of: • a bundle is too long • a bundle contains more wires than necessary (eg switch to a shared power and data bus) • a bundle is completely unnecessary (sometimes separate modules can be combined/eliminated) • in some rare instances, wireless data transmission can be used • ultimately, switching from 12 V to medium-voltage (48-54 V) can eliminate multiple wires needed for high power modules. [0] https://youtu.be/XDtE-Stzol8 https://youtu.be/XDtE-Stzol8

fsociety 4y ago

Wiring is a very hard problem in vehicles. It’s why you see physical switches being switched out for a touchscreen, and some of the tech the big automakers are most excited for are, at the end of the day, just to reduce the amount of wiring required for each car.

anaganisk 4y ago
If we are doing bad trade-offs, let's run like flintstone cars instead of an engine. It does sure take up a lot of space and is very heavy.
foepys 4y ago
Switches in cars don't directly connect to the thing they control. They haven't for decades now. [1] The connector of a touchscreen and a unit full of switches can be exactly the same. 1: https://en.wikipedia.org/wiki/CAN_bus https://en.wikipedia.org/wiki/CAN_bus
- wiml 4y ago
  Or, for that matter, https://en.wikipedia.org/wiki/Local_Interconnect_Network https://en.wikipedia.org/wiki/Local_Interconnect_Network

jmoak3 4y ago

To add to the other replies - the networking configuration of the car plays a huge role as well! Is it CAN bus? Is it Ethernet? Is it a mix? How many computers are in it? How are they connected? Have you centralized the microcontrollers to some degree? What about connections between microcontrollers? Just like microservice oriented architectures and monoliths, you may choose the form of your destroyer, and an extraordinarily well-connected topology with no centralized points to bounce between can lead to ass loads of wires :) I'm convinced of the quality of Tesla's internal networking - I don't have concrete data on this but the capabilities they showed in 2018 such as over-the-air updates told me they had to be more sane than their competitors. To be able to update any part of the car like that I'd imagine they centralized a TON of the random bits and bobs into a few Ethernet connected machines even back then. On top of that, the rumors of the telemetry they collect is the stuff of legend! The problem with a lot of these car companies is that they're a little behind the tech curve. I left automotive in 2018 so I may be old news here but in-house out-sourced was still a large debate when it came to the design of such systems. It will take a while for them to bubble up leadership with relevant experience to make the right calls - maybe with the layoffs at big tech co's it'll happen sooner than later? Automotive companies I interacted with in 2018 definitely knew then what they wanted, the hard part was finding the right people to deliver and manage.

satiric 4y ago
I understand that there's gonna be a lot of wiring, having done a lot of vehicle wiring myself. What I don't understand is how they ended up with so much more wire than necessary. Is it from putting wires in the harness that didn't actually need to be there, or is it from routing the harness in a suboptimal way?