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JointReaction analysis.....

Posted: Mon Sep 14, 2009 12:16 pm
by ananthgk
The JointReaction analysis does not work when I load the actuators, controls and walk states for the RRA. Am I doing something wrong here, or was the tool meant to work only when CMC data was loaded??

Part II of the question....

Posted: Mon Sep 14, 2009 12:23 pm
by ananthgk
Would the JointReaction analysis results be the same for RRA and CMC data??

RE: JointReaction analysis.....

Posted: Tue Sep 15, 2009 10:35 am
by mdemers
Could you be more specific? What errors are being thrown?

The tool will work with RRA results. The key is that the states you supply must match the states in the model. In the analyze tool, just supply the RRA states file, load the RRA actuators (be sure to replace the model's actuators and not append to them), and load the ground reaction forces+kinematics file. You do not supply controls if you want to use the actuator activations from the states file.

Matt

RE: Part II of the question....

Posted: Tue Sep 15, 2009 10:42 am
by mdemers
It depends on how they are actuated. If your RRA is driven only by torques actuators (as it is normally) and your CMC is driven by muscle actuators which are just complicated force actuators, then JointReactions will give very different results.

RE: JointReaction analysis.....

Posted: Tue Sep 15, 2009 11:29 am
by ananthgk
Thanks Matt,

But the RRA states file only contains the joint coordinates and their velocities. So shouldn't we include the RRA controls file so that the values of the residual forces and joint actuators are known?? ..... and these would affect the values of the joint reaction forces.

I also tried both techniques (trying to replace CMC controls by RRA controls, and your suggestion of just including states) but the tool does not even start, software hangs for a while and then I get the message 'Tool execution failed or canceled by user'.

Thanks