The braking problem – energy analysis

I’ve been just talking about regenerative braking for too long. It’s time to define the requirements.
When trying to dimension ultracapacitors or batteries for regen braking, we have to take into account the energy and power of the braking in it’s worst case: from top speed down to zero, and in the shortest time possible. Let’s [...]

Redoing the highway math

I haven’t had the time or the patience to repeat the roll-down test again. However, I found an old picture file I took out of the Web a few years ago that has all the measures of my car, and, most importantly, it has a perfect frontal area projection!

With a little help from [...]

Sensible A-class physics

“Portuguese drivers in the greater Lisbon area last monday were surprised by a strange scenario: a crazy dude with a camera and tripod in the backseat of the car, going back and forth on the same road, over and over again, accelerating to 80 kph and then letting the car stop by itself. He spent [...]

Architecture redone

After careful consideration of the usage cases and a few other deployment constraints, I remade the architectural document.
The plan now spans 4 phases, instead of 3. Just being careful.
This time I also included a sub-project breakdown. Boy, this thing really is big… so far its weight is 18 different work packages. Yummy. Work, work, work.
It [...]

Architectural Overview

It’s about time I put things down on paper and see what’s missing.
I’ve written a high-level requirement specification of the whole system (click for PDF).
It outlines my approach in 3 phases (Motor Development, Parallel HEV, Serial HEV) as well as the layout of the electric system for each phase.
Comments?