Electric cars

Electronic design posted an interesting article on the electric car. Here's an image of the Baker Electric, from the early 1900s. Wow.

Summer camp starting

Today is the beginning of the robotics portion of Summer Bridge camp I'm helping with. Looking around the web, I ran across another interesting teaching robot, the Finch. The Finch can use Myro, a Python robotics library aimed at education; I might take some ideas from that.

A team is driving an autonomous robot for 13,000 km -- wow! They start tomorrow.

Almost done

My time here at Eglin AFB is almost over. It's been a great time! I've enjoyed learning a lot of new things and using skills I've developed over the years to solve some of the problems. I gave a presentation, but can't distribute it publicly until I get it approved.

I recently discovered several wonderful GMail labs features on their blog: hierarchical labels, archive and send, SMS chat, and offline mode. Also, I learned that I can drag and drop attachments. Wow! That's muuuuuch better.

Now, for random links:

• BBQ by engineers
• An open-software, open-source robot from Kuka for just $24,000.

A fun video!

To do

I tried searching for a paper to go with the quad-rotor video I posted yesterday, but no luck. I did find a couple of other papers, though.

Today's tasks:

1. Review paper
2. Quad-rotor dynamics
3. Get wireless Matlab control working
4. Work on P&T
5. Look for Summer Bridge assistants
6. Work on parts list -- 6 V and 3.3 V DC-DC converters; price for Meanwell unit

Quad-rotor and LiPo

Some notes on LiPo batteries:

1. Here's a good summary. In particular:
1. We need a connector to mate with the battery's taps, to check that each cell is fully charged. A charge balancer would be nice; I've added one to the parts list.
2. We need a safe charging set-up, with a bucket of sand handy and probably a Pyrex dish with sand to charge batteries in.
3. Don't charge at more than 1C.
4. Our ESCs have a built-in low-voltage cutoff that is set to (starting battery voltage) * 0.74. So, the batteries MUST BE FULLY CHARGED BEFORE CONNECTING THEM for this to work properly.

Now, what neat things can a quad-rotor do?

The list:

1. Look up info re: LiPo charging / discharging
2. Look for 1A inverting regulator
3. Consider appropriate battery for quad-copter
4. Review paper
5. XBee / Bluetooth
6. Finish deriving and document dynamics

To do

The list for today:

1. Paper review?
2. XBee
3. Meeting notes
4. Schedule pest control
5. Dynamics

Today's plans

I finally figured out why my OpenCV code didn't work: there was a transpose in one matrix and I didn't understand how OpenCV lays out memory (it pads each column so that it's a multiple of 4 bytes). In general, indexing in OpenCV involves a painful cast; this is the most helpful summary of how to do that.

I still can't get two XBee modems to communicate; I'm not sure what I'm doing wrong. I just found a nice howto and a tutorial which looks like the right things to try.

Plans for today:

1. E-mail / admin
2. Derive dynamics for the quad-rotor
3. Work on a list of reviewers for my P&T application
4. Start deriving continuum dynamics
5. Order breadboards, PICKit2s, mini-Bullys, etc.
6. Prepare for meeting with Jimmy, TJ
7. Work on recruiting Summer Bridge helpers