5 ms·

Do EVs not have all of the ancillaries hanging off CANBUS or something? Or is the lion's share of chips in an ICE vehicle engine and transmission control?

by hnov 5y ago

SV_BubbleTime 5y ago
Of course. There isn’t an EV in the world that is less complex than it’s ICE counterpart. GP is very mistaken. I wrote a longer explanation above.
- elihu 5y ago
  Most of the complexity of EVs is just generic modern car complexity, though. EVs don't have to be any more complicated than ICE vehicles, and EV conversions especially are usually really simple (though to be fair a lot of the vehicles being converted are old classic cars that didn't have any computers in them to begin with). The EV drivetrain might have more or less computers than an ICE drivetrain, but really managing batteries and a motor isn't inherently all that complicated. On the ICE side of things you have a lot more moving parts and the necessity of keeping everything properly tuned so it can pass emissions checks. Braking and traction control I could see being fairly complicated, but it's a similar problem whether it's an ICE engine or an electric motor. Self-driving is hugely complicated, but that's not complexity that's inherent to EVs specifically, it's just a feature that's usually only implemented on EVs for some reason. All the other stuff: infotainment, tire pressure sensors, back up cameras, and so on are just modern car complexity.
  - SV_BubbleTime 5y ago
    The braking is way way more complex because of regenerative. That isn't a factor with ICE. Trust me - it's not simpler. I know you think we just apply power to the motor and go, but that is not the case. There are facets of "soft start" and it ties in to traction control, there are efficiency processes, etc. Instead of map tables for rpm and injection, you have battery heating and cooling targets with current sensed feedbacks and torque targets, and bla bla bla. Stop making me bring work home with me! ;) EVs are not simpler. It's literally impossible in automotive to ever get simpler. At least since the 1970s. I think we're hitting a point of unsustainability and the people in charge think OTA firmware is going to fix that, I think it'll make it much worse. EDIT: fwiw, I wish I could go back to a time when backup camera was even mention worthy of "things I consider complex in a vehicle". It's just a couple shielded wires and plugs into the radio/telamatics. I can tell you without a doubt that the starter in most vehicle is now far more complicated, to the point it too has it's own microcontroller and data bus (typically LIN, not sure I've seen a CAN yet).
    - galangalalgol 5y ago
      I agree it isn't simpler. I only assert that it could be if you ignored all those efficiency gains from regenerative braking and battery temp management. Things that aren't often in ev conversions. But you made me realize that is apples and oranges, because an ICE that gave up on efficiency could be an old vw beatle with aie cooling and a carburetor. I feel you on the seemingly endless stairway of complexity. I work in embedded safety critical and I often tell people to never do anything in software they could have done in hardware. Hardware is cheaper bat this point...
      - elihu 5y ago
        Most conversions have regenerative braking nowdays. Most AC motor controllers support regen as a basic feature. A lot of the old series-wound DC motor conversions didn't have it because it was hard to do on that kind of motor (similar how it's hard to reverse; you have to flip the polarity of one set of leads but not the other, which requires a bunch of contactors or IGBTs or something). Where regen gets kind of complicated is that you generally need to turn regen off when someone slams on the brakes. Unless the traction control / antilock braking system knows how regen figures into its calculations and can apply the proper braking force to each wheel taking it into account. I don't know what OEM EVs typically do in that situation, but for conversions you usually just have a brake switch so that regen can be automatically disabled when you're actually braking.
        galangalalgol 5y ago
        What does the software industry look like for this stuff? I've got two decades of embedded c++ experience, some of which is safety critical. How much of automotive is offshored these days? Is it still mostly C and a bsp and a text editor, or is it gitlab and pipelines now?
        elihu 5y ago
        I don't know, I'm just familiar with what the motor controllers do because I'm trying to do an EV conversion. I would imagine that the people working on parts for the conversion market have a somewhat different development process than a regular auto manufacturer, in part because they're making things in low volume and in part because they just have to design generic reusable parts that do one thing properly. If you're building a whole car, you have to make sure everything works together as a cohesive whole. In some ways that would be easier because you know exactly what parts are being used together. I would hope that most of the safety-critical real-time software that controls a car's basic functions like braking and traction control and so on would be relatively simple and straightforward, but maybe that's too much to expect. My understanding of the way the auto industry works these days is that the major manufacturers are increasing dependent on a complicated network of 3rd-party parts suppliers, and I'd expect that to influence the character of the software stack somewhat.

Do EVs not have all of the ancillaries hanging off CANBUS or something? Or is the lion's share of chips in an ICE vehicle engine and transmission control?

by hnov 5y ago

Do EVs not have all of the ancillaries hanging off CANBUS or something? Or is the lion's share of chips in an ICE vehicle engine and transmission control?

SV_BubbleTime 5y ago

Of course. There isn’t an EV in the world that is less complex than it’s ICE counterpart. GP is very mistaken. I wrote a longer explanation above.

elihu 5y ago
Most of the complexity of EVs is just generic modern car complexity, though. EVs don't have to be any more complicated than ICE vehicles, and EV conversions especially are usually really simple (though to be fair a lot of the vehicles being converted are old classic cars that didn't have any computers in them to begin with). The EV drivetrain might have more or less computers than an ICE drivetrain, but really managing batteries and a motor isn't inherently all that complicated. On the ICE side of things you have a lot more moving parts and the necessity of keeping everything properly tuned so it can pass emissions checks. Braking and traction control I could see being fairly complicated, but it's a similar problem whether it's an ICE engine or an electric motor. Self-driving is hugely complicated, but that's not complexity that's inherent to EVs specifically, it's just a feature that's usually only implemented on EVs for some reason. All the other stuff: infotainment, tire pressure sensors, back up cameras, and so on are just modern car complexity.
- SV_BubbleTime 5y ago
  The braking is way way more complex because of regenerative. That isn't a factor with ICE. Trust me - it's not simpler. I know you think we just apply power to the motor and go, but that is not the case. There are facets of "soft start" and it ties in to traction control, there are efficiency processes, etc. Instead of map tables for rpm and injection, you have battery heating and cooling targets with current sensed feedbacks and torque targets, and bla bla bla. Stop making me bring work home with me! ;) EVs are not simpler. It's literally impossible in automotive to ever get simpler. At least since the 1970s. I think we're hitting a point of unsustainability and the people in charge think OTA firmware is going to fix that, I think it'll make it much worse. EDIT: fwiw, I wish I could go back to a time when backup camera was even mention worthy of "things I consider complex in a vehicle". It's just a couple shielded wires and plugs into the radio/telamatics. I can tell you without a doubt that the starter in most vehicle is now far more complicated, to the point it too has it's own microcontroller and data bus (typically LIN, not sure I've seen a CAN yet).
  - galangalalgol 5y ago
    I agree it isn't simpler. I only assert that it could be if you ignored all those efficiency gains from regenerative braking and battery temp management. Things that aren't often in ev conversions. But you made me realize that is apples and oranges, because an ICE that gave up on efficiency could be an old vw beatle with aie cooling and a carburetor. I feel you on the seemingly endless stairway of complexity. I work in embedded safety critical and I often tell people to never do anything in software they could have done in hardware. Hardware is cheaper bat this point...
    - elihu 5y ago
      Most conversions have regenerative braking nowdays. Most AC motor controllers support regen as a basic feature. A lot of the old series-wound DC motor conversions didn't have it because it was hard to do on that kind of motor (similar how it's hard to reverse; you have to flip the polarity of one set of leads but not the other, which requires a bunch of contactors or IGBTs or something). Where regen gets kind of complicated is that you generally need to turn regen off when someone slams on the brakes. Unless the traction control / antilock braking system knows how regen figures into its calculations and can apply the proper braking force to each wheel taking it into account. I don't know what OEM EVs typically do in that situation, but for conversions you usually just have a brake switch so that regen can be automatically disabled when you're actually braking.
      - galangalalgol 5y ago
        What does the software industry look like for this stuff? I've got two decades of embedded c++ experience, some of which is safety critical. How much of automotive is offshored these days? Is it still mostly C and a bsp and a text editor, or is it gitlab and pipelines now?
        elihu 5y ago
        I don't know, I'm just familiar with what the motor controllers do because I'm trying to do an EV conversion. I would imagine that the people working on parts for the conversion market have a somewhat different development process than a regular auto manufacturer, in part because they're making things in low volume and in part because they just have to design generic reusable parts that do one thing properly. If you're building a whole car, you have to make sure everything works together as a cohesive whole. In some ways that would be easier because you know exactly what parts are being used together. I would hope that most of the safety-critical real-time software that controls a car's basic functions like braking and traction control and so on would be relatively simple and straightforward, but maybe that's too much to expect. My understanding of the way the auto industry works these days is that the major manufacturers are increasing dependent on a complicated network of 3rd-party parts suppliers, and I'd expect that to influence the character of the software stack somewhat.