3 ms·

It's probably impossible to meet modern emissions, fuel economy, and safety standards without some computer control. I haven't seen an analysis of whether regu

by Zak 1y ago

It's probably impossible to meet modern emissions, fuel economy, and safety standards without some computer control. I haven't seen an analysis of whether regulations preclude those controls being open source and giving the car owner full access. Of course the owner could make the car noncompliant in that case, but the owner can do that on current and past cars using a wrench.

mdp2021 1y ago
> the owner could make the car noncompliant Real dialogue: > "Can we lower the volume of that artificial sound?" // "In the internal configuration; should we modify it, you lose the warranty". Plus, we have heard rumors of "tampering detected: degraded mode activated, contact a service office". Basically, one should avoid in general critical products shipped with kill switches (and in fact I also saw cars that had mulfunctioning kill switches and "shut down" randomly while running).
cout 1y ago
When we think of computers Er think of solid state digital computers. But the first fuel injected vehicles were mechanical computers. I suspect it's still very possible to do the same today, but not practical to design. Also I'm trying to think of what role the computer plays in emissions other than ensuring stoichiometry.
- Zak 1y ago
  Ensuring stoichiometry is kind of a big deal. When the engine is cold, the mixture needs to be rich or it won't start. Engines with carburetors use a choke for that - a valve that blocks some airflow so there's more vacuum, causing the engine to suck in extra fuel. Electronic fuel injection can be much more precise about this, minimizing the amount and duration of enrichment. Changes in air pressure and temperature change the ideal air/fuel ratio. Driving over a mountain will make an engine without the ability to react to run at a suboptimal air/fuel ratio. Catalytic converters require that the ratio be kept very close to optimal to operate effectively. A small deviation for an extended period of time will result in a large increase in emissions and may even permanently damage the catalyst.

by Zak 1y ago

mdp2021 1y ago

> the owner could make the car noncompliant Real dialogue: > "Can we lower the volume of that artificial sound?" // "In the internal configuration; should we modify it, you lose the warranty". Plus, we have heard rumors of "tampering detected: degraded mode activated, contact a service office". Basically, one should avoid in general critical products shipped with kill switches (and in fact I also saw cars that had mulfunctioning kill switches and "shut down" randomly while running).

cout 1y ago

When we think of computers Er think of solid state digital computers. But the first fuel injected vehicles were mechanical computers. I suspect it's still very possible to do the same today, but not practical to design. Also I'm trying to think of what role the computer plays in emissions other than ensuring stoichiometry.

Zak 1y ago
Ensuring stoichiometry is kind of a big deal. When the engine is cold, the mixture needs to be rich or it won't start. Engines with carburetors use a choke for that - a valve that blocks some airflow so there's more vacuum, causing the engine to suck in extra fuel. Electronic fuel injection can be much more precise about this, minimizing the amount and duration of enrichment. Changes in air pressure and temperature change the ideal air/fuel ratio. Driving over a mountain will make an engine without the ability to react to run at a suboptimal air/fuel ratio. Catalytic converters require that the ratio be kept very close to optimal to operate effectively. A small deviation for an extended period of time will result in a large increase in emissions and may even permanently damage the catalyst.