原创 Powering self-driving vehicles

Autonomous, self-driving cars are gaining a lot of attention and even hype these days, typified by the Google car, which has been undergoing extensive road trials. Depending who you ask and which pundit you follow, these driverless cars will be a reality in a few years, or delayed far into the future, or somewhere in-between. Along with the time line, their level of presumed capability will also cover wide span, from handling any situation including dense urban traffic, to perhaps only more limited cases such as open-highway driving.

What's in the autonomous car and what makes it work has been covered extensively in both the less-technical as well as technical media; two of the many examples are here and here. Whatever the eventual reality of the autonomous vehicle, one thing is for sure: they will require a lot of electrical power for all those high-profile sensors – radar, sonar, vision, and LIDAR (Light Detection and Ranging) are just a few  – and even more for the less-obvious but enormous computational MIPS needed to process the huge amounts of data from them.  
 

Yet despite the many stories on these vehicles, there is one important area where I feel pretty much in the dark. All the coverage I have seen or found via web searches is about the sensors, the signal processing, the algorithms, the user interface, and the control mechanisms – but how the car powers all of the electronics is a technical mystery. I have not seen any credible block diagrams for the power-supply subsystem or even basic numbers on how much electrical power is needed. Even with low-power design, I assume it's in the multi-kilowatt range – but how many?

There are additional questions, of course. How does the power subsystem look in an all electric vehicle (EV) compared to one in a hybrid (HEV) or a conventional internal-combustion (IC) design? Further, any numbers on the power needed brings the inevitable closely related question: how do you dissipate all the heat that the supply (even if it is efficient) and the loads generate? Given that today's non-autonomous vehicles are straining to supply power to all their new electronics, some automakers are looking to supplement the long-established 12-V basic battery rail with a more-efficient 42-V system, see here (déjà vu flash-back: this is actually an idea which has come and gone, but may be coming again, as seen here and here).

I have seen press releases about individual components such as MOSFETs used in autonomous vehicles, but that's looking at a tree when I want to see the forest. Do you have any insight into the power subsystem requirements, implementation details, or thermal design of autonomous vehicles?