SimTK: OpenSim: [#2046] CustomJoint vs. FreeJoint between body en world

Share
Follow	Project Follow publicly Follow privately Unfollow See followers (304) List Map More info

Trackers

Date:
2014-10-23 11:29

Priority:
3

State:
Open

Submitted by:
Maarten Afschrift (maaafsch)

Assigned to:
Ajay Seth (aseth)

Summary:
CustomJoint vs. FreeJoint between body en world

Detailed description
Dear OpenSim developers, I've found a bug in OpenSim 3.2. I had problems with invers dynamics calculation with my exoskeleton model (attachment). When I used a FreeJoint to connect to pelvis with the world the joint moments calculated by ID were wrong. I 'solved' this by using u CustomJoint for the connection between the pelvis and world (I found this on the forum: https://simtk.org/forums/viewtopic.php?f=91&t=3544). In attachment you can find an example movement, the ID solutions and the two osim models (one with FreeJoint and one with a CustomJoint). Best regards, Maarten Afschrift
Dear OpenSim developers, I've found a bug in OpenSim 3.2. I had problems with invers dynamics calculation with my exoskeleton model (attachment). When I used a FreeJoint to connect to pelvis with the world the joint moments calculated by ID were wrong. I 'solved' this by using u CustomJoint for the connection between the pelvis and world (I found this on the forum: https://simtk.org/forums/viewtopic.php?f=91&t=3544). In attachment you can find an example movement, the ID solutions and the two osim models (one with FreeJoint and one with a CustomJoint). Best regards, Maarten Afschrift

Comments (1)
Attachments
Changes

Add A Comment:

Message
Date: 2014-10-23 17:11 Sender: Ayman Habib Ajay, don't know if this's expected, can you comment? Thanks.

Attachments:

Size	Name	Date	By	Download
16 KiB	bug_report.zip	2014-10-23 11:29	maaafsch	bug_report.zip

Field	Old Value	Date	By
assigned_to	aymanh	2014-10-23 17:11	aymanh
File Added	564: bug_report.zip	2014-10-23 11:29	maaafsch

SimTK is maintained through Grant R01GM124443 01A1 from the National Institutes of Health (NIH). It was initially developed as part of the Simbios project funded by the NIH as part of the NIH Roadmap for Medical Research, Grant U54 GM072970.

Version 4.2.2. Website design by Viewfarm. Icons created by SimTK team using art by GraphBerry from www.flaticon.com under a CC BY 3.0 license. Forked from FusionForge 6.0.5.

Feedback