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Xan
11-05-2009, 10:39 AM
Hi,

Besides updating and improving the phoenix code Iím also working on Terrain adaption. Iíve already posted (http://forums.trossenrobotics.com/showthread.php?t=2754) some test setups about the sensors using the phoenix. The FSRís in combination with this setup didnít give me the wanted reliability. Now Iím using some Micro switches to Ďfeelí the ground.

I thought I share the progress made by showing the vids.

Shows that the hex feels the ground:

http://www.youtube.com/watch?v=2hA1rsTuHcg

First walk over an object:

http://www.youtube.com/watch?v=tU-9Ih5EsCo

Note that there is still a lot of work to do. Thatís why the hex is a bit wobbly while walking. The speed isnít optimal as well. But we are 'slowly' getting there. ;)

Xan

darkback2
11-05-2009, 11:15 AM
Sweet work Xan,

Question...well...2 questions...

Are you using a sensor in the body to detect body roll? or is it all done through pressure on the feet?

Are you just having it match pressures between the feet that are in the down position? or are you looking for a target pressure for each foot in the down position?

How are you dealing with feedback loop issues?

Ok...thats three questions.

DB

nagmier
11-05-2009, 11:34 AM
@ DB... He said he switched to micro switches so I don't think they will have "pressure readings"

@ Xan awesome work so far looking great... And I love that transmitter(I've read the thread @ lm.net)! one day I will build one!

darkback2
11-05-2009, 11:46 AM
Thanks nagmier...didn't catch that...so foot lowers until it trips the switch, then stops and holds position...

DB

sam
11-05-2009, 11:48 AM
This is great work!

I will be waiting for more updates ;)

Adam
11-05-2009, 01:00 PM
This is an interesting project. I also plan to do a form of terrain adaption. Would you mind providing more information about the micro switches?

rebel
11-05-2009, 01:08 PM
Amazing work, wish i could do that. :p

Xan
11-06-2009, 03:13 AM
Hi all,

Thanks for the reactions.


so foot lowers until it trips the switch, then stops and holds position... Yes that is how it works in a nut shell. Iím only using 6 contact (microswitch) sensors on the tars. ĎBalance modeí keeps track of the average leg height and angle and translate it to the body angle and position. This is going a closed loop setup to keep the body at the same height even when it walks in a hole.

Iím currently upgrading the body angle calculations to make it more precise. This will solve the shaky body shown in the video.

I hope this answered your 2 uuhhÖ 3 questions ;)


@ Xan awesome work so far looking great... And I love that transmitter(I've read the thread @ lm.net)! one day I will build one!I just canít say this enough; the remote is awesome! It gives the precision of a stock RC flight remote but also allows me to send digital signals to switch gaits and modes. Itís open source and runs on a BAP28. So the remote is getting better and better every week ;)


This is an interesting project. I also plan to do a form of terrain adaption. Would you mind providing more information about the micro switches?
Sure, hereís a offside link to the build (http://www.lynxmotion.net/viewtopic.php?t=4579)

Xan

Quarkster
01-17-2010, 12:35 AM
I don't think improving the precision of your body angle calculations is going to completely resolve your shakiness problem. You are never going to get it so precise that error doesn't build up over time, and it that will never be able to tell it the difference between walking uphill and leaning over. Something like a gyroscope could go a long way towards improved stability.