Vision-Based Autonomous Robot Self-Docking and Recharging

Thanks for sharing your work with us.

Joe Dunfee

I noticed in your paper that you attributed an electrical docking failure to "unseen dirt and dust".

While I don't have any realworld experience with this issue, I suspect the problem may have been with the use of aluminum plates. I've read that aluminum very quickly gets "rusted" (a coating of aluminum oxide.) Unfortunately for your use, aluminum oxide is a very good insulator. So, while aluminum itself is a good conductor, it is a poor metal for making electrical connections.

Can anyone else recommend a better choice that is easily to obtain?

Joe Dunfee

You are right, that's what I wrote. I think that one of the reasons for that is that people touched the aluminum surfaces many times and it leaves signs of fingertips (fat). I might had to clean it with a liquid such as Terpentin.

Next time I would use copper instead of aluminum.

Please note that there is a video of this work as well:

To download:

Uri.

snipped-for-privacy@yahoo.com wrote in news:1143091097.670601.197650 @j33g2000cwa.googlegroups.com:

The metal used in battery holders could be used as is or as raw material. They're cheap from Digikey, Jameco, etc.

Mitch

THAT is pretty cool! Good job!

I've seen AC signals used with sensors submerged in liquids to help prevent them from corroding. Would a similar approach to power transfer help keep the contact plates from oxidizing?

Chris

If you're struggling with the contact problem, replace the aluminum surfaces with thin stainless steel sheet. It won't cost much for the area you've got, thin sheet can be cut with tinsnips, and it won't oxidize. There are other materials that will work, too, but stainless sheet is easily available. The aluminum oxide coating that forms on aluminium is a poor conductor.

For contact brushes, copper wire brushes would be good.

John Nagle Animats

pogo wrote:

The cause of the oxidation is not the electrical current. It is just the O2 in the air. Most people aren't aware of this oxidation because the process is self limiting. The initial layer of Aluiminum Oxide tends to protect the aluminum underneath. So, only a fairly thin layer tends to form. This is as opposed to Iron rust, which will progress much deeper into the metal, and make the process much more visible.

Joe Dunfee