Robogames Day 3 pics question.

[DirtyRoboto]

If you follow this link...
http://www.flickr.com/photos/95721430@N ... 387868322/
There is a picture in a sequence of an RN doing stairs. I would like to talk to the Robots owner as their technique is missing a key frame.

Marcus.

[bauermech]

I do believe that robot is Kugai. I think he got the gold for going both up and down the stairs... could be wrong though.

[hivemind]

I think you are correct Matt - very impressive stair climbing technique... and to think we were trying so hard...

Marcus, I think that if you go a few frames ahead of the picture you referenced then you are able to see more of his technique. For the most part, he just kept it simple - which is always for the best.

[DirtyRoboto]

I have seen all of the piccys and I know that the guy taking the shots may have missed a keyframe. But my stair climb looks well different to the pics.
I use balance xfer in small points of contact initially and I also use momentum and break balance to get a more effcient stair gait.

The key frames I am missing are best described by decent. On decent of stairs my routine tilts the foot to 45' toe up, moves the leg forward and down while the other leg aids this move and aids to break balance for a moment. As forward balance is broken the lowered 45' foot returns to -15 as the other leg retracts for clearance and then joins the other leg.

I have had Takeshi do one step per stair by pushing balance foward and syncing the legs and arms with gravity. This only worked a few times and was very dependent on environment and placement.

Marcus.

[DirtyRoboto]

Let me just add, that I often work in future tense with motion capture. I will take an end position capture and work back from that point, then I reverse the code.
I can know how the robot needs to be, to push off with one foot and compensate with the other foot to absorb the momentum by using this method.

M.

[tempusmaster]

I have seen all of the piccys and I know that the guy taking the shots may have missed a keyframe.

The camera was set to multiple shot mode, and takes three quick shots in a row, then pauses to process them before another series can be taken. We have videos as well, which will show the complete sequence, but those won't be posted until after we get back to Japan this weekend and have a day or so to recover.

[DirtyRoboto]

While we are on the subject. I would like to thank you tempusmaster for providing all of the juicy bits on the games. I loved your pictures and am waiting for the videos so I can see the latest stuff. Good job and again, Thank you.

Marcus.

[DirtyRoboto]

OMG OMG!
I just saw the stairs video on robot-dreams and was shocked!!!

Not one robot used alternate legs to climb. The feet are moved for no reason into poor positions, the speed is slow and with poor accuracy.

I wish I had shot a video of Takeshi doing stairs before I started modding. The AI version was very slow but my basic stairs was at the same speed as FORWARD_WALK using altrenate legs and also using the feet as brake levers. At one point T pushes off with the rear foot and the lower front foot catches the fall with the heel and in a rapid move that rubs off the speed and unbalance, flattens the foot and shifts weight.

Check out my Balanced Side drop attacks (SD attacks) video for an example of how to break balance and time the reponse. In the second attack you can clearly see the right foot (left of screen) maintains position with the balance is broken and the robot falls over. I had posed the bot in the finish position and captured it. I then lifted the bot to about 30mm before landing and captured again. The pre-landing pose is triggered at high speed without a WAIT into the landed pose. The result is a slight adjustment to balance and posture to inbetween the move into landing.

http://www.youtube.com/watch?v=0-5ZSQJnhNw

Marcus.

[tempusmaster]

OMG OMG!
I just saw the stairs video on robot-dreams and was shocked!!!

Not one robot used alternate legs to climb. The feet are moved for no reason into poor positions, the speed is slow and with poor accuracy.

Actually, I need to apologize to the competitors in that video because I didn't give enough background in the Robots Dreams post.

Very few of them had ever attempted the stairs before, and only one - Kugai - had pre-registered for the event. I think they did extremely well for trying this difficult challenge on the spur of the moment with only an hour or so at most to prepare.

[StuartL]

I watched these guys prepare for the stairs. The most dedicated of them all spent 2 hours preparing and it's amazing that he succeeded. Others managed varying degrees of success, some fighting with software issues, others distracted by other competitions.

To achieve stair walking at all isn't an easy job. To do it in a few hours is astonishing.

[DirtyRoboto]

My basic stair walk routine was done in 4 hours, this includes building the stairs and setting up a level worksurface.

I dont wish to detract from any of the good work shown, I just want to point out that there are simple solutions to complex problems. My solve was simple but it was based on many complex and involved ideas.

I am of the mind to un-mod my RN and make him factory reset to his normal config just to record it on video.

Again, I wish to take nothing away from the guys at the Robogames, I just wish I could have been there to exchange ideas.

Marcus.