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Final Project

Unread postPosted: Mon Dec 12, 2011 4:10 pm
by F11Carrie
In the valve-train ADAMS assignment there is a primitive joint that was part of the files we were given. How do you create that type of joint?

Re: Final Project

Unread postPosted: Tue Dec 13, 2011 12:49 am
by Dan Negrut
F11Carrie wrote:In the valve-train ADAMS assignment there is a primitive joint that was part of the files we were given. How do you create that type of joint?


Toby - can you please follow up on this?
Dan

Re: Final Project

Unread postPosted: Tue Dec 13, 2011 12:42 pm
by TobyH
The valve-train example uses an 'inplane joint primitive'. This says that a point on the first body is constrained to move in a plane on the second body (at least I think it is this way... maybe it is the other way around). You can add this by going to Build->Joints... Then you can see the joint primitives (parallel, perpendicular, orientation, inplane, inline). You add them like a revolute joint (select each body, then the point). If the plane is oriented incorrectly, right-click on the joint, select modify, then click the Change Position button. You can rotate the plane about the point, for example.

Re: Final Project

Unread postPosted: Tue Dec 13, 2011 4:31 pm
by F11Jonathan
Professor Negrut, could you make a dropbox for the final project on Lear@UW?

Re: Final Project

Unread postPosted: Tue Dec 13, 2011 5:34 pm
by TobyH
The dropbox should be there now.

Re: Final Project

Unread postPosted: Wed Dec 14, 2011 3:29 am
by F11Christopher
Professor,

Can you elaborate on what all needs to be submitted with the final project. Basically, is this a full report or just a simple presentation of results?

Re: Final Project

Unread postPosted: Wed Dec 14, 2011 8:08 am
by Dan Negrut
F11Christopher wrote:Professor,

Can you elaborate on what all needs to be submitted with the final project. Basically, is this a full report or just a simple presentation of results?


Chris - in one page of text, explain the problem that you solved. Then include plots and explain what they are and why they are correct (or point out any problems that showed up). Conclude with a couple of remarks.
I hope this helps,
Dan

Re: Final Project

Unread postPosted: Wed Dec 14, 2011 7:20 pm
by F11Carrie
Is there a way to slow down the playback of a simulation in ADAMS? I'm having a little trouble seeing what's going on with my model.

Re: Final Project

Unread postPosted: Thu Dec 15, 2011 12:27 am
by Dan Negrut
F11Carrie wrote:Is there a way to slow down the playback of a simulation in ADAMS? I'm having a little trouble seeing what's going on with my model.


I contacted two of my students (Justin and Makarand), you'll hear from one of them...
Dan

Re: Final Project

Unread postPosted: Fri Dec 16, 2011 2:56 pm
by F11Carrie
For my project, I'm attempting to build a "passive dynamic walker" model similar to figure 2 in this paper http://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=1435483. However, I'm having issues with keeping it upright. I've been applying an initial forward velocity to the lump mass at the hip, but the problem that I'm having is that if the speed is too great, the back leg (initial stance leg) hits the ground too soon and trips the model, but if the speed is too low, the back leg never touches the ground and just flies around (think cartoon character slipping on a banana peel). I can't find a value that lets the model get past the first step successfully (down to .0000001 m/s). Any suggestions?

The spheres in place of "feet" have a contact force between them and the green box (my floor), there are revolute joints at the hips. I did add an additional force to the leg that's behind because otherwise it wouldn't swing forward much at all.


project.png
project.png (30.29 KiB) Viewed 30180 times

Re: Final Project

Unread postPosted: Fri Dec 16, 2011 11:19 pm
by Dan Negrut
Carrie - This actually looks quite interesting. As i told you, the project you wanted to do is challenging. You'd need a good control law to make the "biped" move; i.e., step, the way you'd like it to. This is not simple and honestly it would be quite amazing if you can do it given the amount of time you had to work on the Final Project.
Don't feel bad if you can't get it to work the way you'd like.
Dan