inverse kinematics of new components

[mohamad rasool mohamadi]

hi,
can i find the positions of new components added to the model(exoskeleton), by adding marker to components and using IK tool. if not , how can i produce the new inverse kinematics file containing the new components positions, because i need it for further simulations.(i don have the motion capture file of new components).
thanks

[Thomas Uchida]

can i find the positions of new components added to the model(exoskeleton), by adding marker to components and using IK tool.

Yes. You can report model marker locations (in the ground frame) by setting the report_marker_locations flag to true in the IK setup file. See Help -> XML Browser -> InverseKinematicsTool in the GUI. (Note: You may need to add these markers in your TRC file and setup file as if you were tracking them, but set the tracking weights to zero.)

[mohamad rasool mohamadi]

can i find the positions of new components added to the model(exoskeleton), by adding marker to components and using IK tool.

Yes. You can report model marker locations (in the ground frame) by setting the report_marker_locations flag to true in the IK setup file. See Help -> XML Browser -> InverseKinematicsTool in the GUI. (Note: You may need to add these markers in your TRC file and setup file as if you were tracking them, but set the tracking weights to zero.)

hi . i have faced this error:
InverseKinematicsTool Failed: AssemblySolver::assemble() Failed: SimTK Exception thrown at Assembler.cpp:227:
Error detected by Simbody method AssemblerSystem::objectiveFunc(): calcGoal() method of assembly condition Markers returned a negative or non-finite value -1.#IND.
(Required condition 'goalValue >= 0' was not met.)
here are the steps that i have done:
1) i have added new components( exoskeleton) to a human model. joints and constraints are defined
2)as i mentioned i do not have any motioncapture(trc file) of exo and i want the inverse kinematics of this augmented model so i can use it for CMC simulation ( i need my actuators forces)
3) i have added new markers to new components and defined them in .osimfile , ik setup file and also i have added them in .trc file of human(just names and X , Y, Z columns) as u said
4)when i use IK tool i face the mentioned error ( i have set the "report-markers-locations" flag to true)
here is my questions: why this error appers( is there any mistakes in mentioned steps)? where the markers positions will be written and how can i convert them to IK?
sorry if i asked a lot in one post.
thanks

[Thomas Uchida]

i do not have any motioncapture(trc file) of exo and i want the inverse kinematics of this augmented model so i can use it for CMC simulation

If you don't have experimental data, then it isn't clear why you are using the Inverse Kinematics Tool. "The Inverse Kinematics (IK) Tool steps through each time frame of experimental data and positions the model in a pose that 'best matches' experimental marker and coordinate data for that time step." (https://simtk-confluence.stanford.edu/d ... Kinematics)