Hacker News new | ask | show | jobs
by BotJunkie 1988 days ago
I'm the author of this. It was certainly surprising to learn that a lot of what AVs are doing right now is limited by the amount of power available to the computers. It didn't make it into the article in full, but we were told that in general more computing power means detecting and classifying more object types, tracking those objects over longer periods of time, and doing more detailed motion prediction and planning across longer time horizons. They were explicit that the power they can squeeze out of the vehicle's alternator is currently a significant limiting factor to the performance of the system.
3 comments

I am not a car specialist, but I am not buying this. Alternator can be upgraded: https://www.trucknews.com/products/600-amp-alternator-for-mi...

With 600 amps@24V one has 10 kW power for computers and the truck. That’s what 300 decent graphic cards consume.

I immediately thought about the car stereo guys they run stronger alternators and power massive amount of subs and speakers. But I know nothing about big trucks and their electrical needs. They have refrigeration and other electrical needs I am unsure of.
You made me curious. Big refrigerators and shipping containers have their own diesel engine: https://en.m.wikipedia.org/wiki/Refrigerator_truck They are independent from big truck’s power system. That is a solution for powering electronics - external diesel generator.
10 kW is almost 10% of the max output of the engine in a honda civic. for another comparison, that would be like running three typical car AC systems at max simultaneously. so not infeasible, but a meaningful hit to fuel economy in a smaller vehicle. it would be even more detrimental to the range of a small EV.
If so, why not use cars without alternators? 48V mild-hybrids have much higher capacity starter-generators instead of alternators, and electric cars can generally pull power from their batteries at the same rate they can charge it. For example, for a Tesla Model 3 that's 250 kW.
Hybrids are absolutely the most effective way to go here in the near term, there is just no question in my mind. I'm honestly very, very surprised we haven't seen that take off yet-- either it's a lot harder than it looks, or owners of large fleets are irrationally gunshy. I've been expecting it to show up and start kicking ass any minute now for at least the last 7 years.
Seems like electric vehicles are not limited by this problem of power availability. One just has to be concerned by how much that power consumption for computer operation affects vehicle range.