Hi,
As it is summarized in the subject, I search a way to create a moving path point whose coordinates depend on several control coordinates. For instance, in the Stanford VA upper limb model, I try to define a path point for the middle deltoid which will move as a function of the shoulder elevation (one SimmSpline) as well as the shoulder rotation (a second SimmSpline).
Thanks for your help.
Best regards,
Nicolas.
Several control coordinates for a moving path point.
-
Nicolas Eydieux
- Posts: 12
- Joined: Tue Dec 10, 2013 3:20 am
Re: Several control coordinates for a moving path point.
Hi Nicholas,
You can define the x,y,z locations of a moving point by independent simmsplines. A good example of this is in the gait2392 model (rect_fem_r-P3).
__________________________________________________________________________________________________________
<MovingPathPoint name="rect_fem_r-P3">
<location> 0.0617576 0.020984 0.0014</location>
<body>tibia_r</body>
<x_location>
<SimmSpline>
<x> -2.0944 -1.99997 -1.5708 -1.45752 -1.39626 -1.0472 -0.698132 -0.526391 -0.349066 -0.174533 0 0.00017453 0.00034907 0.0279253 0.0872665 0.174533 2.0944</x>
<y> 0.0155805 0.0179938 0.0275081 0.0296564 0.0307615 0.0365695 0.0422074 0.0450902 0.048391 0.0534299 0.0617576 0.0617669 0.0617762 0.0633083 0.066994 0.0733035 0.0573481</y>
</SimmSpline>
</x_location>
<x_coordinate>knee_angle_r</x_coordinate>
<y_location>
<SimmSpline>
<x> -2.0944 -1.99997 -1.5708 -1.45752 -1.39626 -1.0472 -0.698132 -0.526391 -0.349066 -0.174533 0 0.00017453 0.00034907 0.0279253 0.0872665 0.174533 2.0944</x>
<y> 0.0234116 0.0237613 0.0251141 0.0252795 0.0253146 0.0249184 0.0242373 0.0238447 0.0234197 0.0227644 0.020984 0.0209814 0.0209788 0.0205225 0.0191754 0.0159554 -0.0673774</y>
</SimmSpline>
</y_location>
<y_coordinate>knee_angle_r</y_coordinate>
<z_location>
<SimmSpline>
<x> -2.0944 0.1745</x>
<y> 0.0014 0.0014</y>
</SimmSpline>
</z_location>
<z_coordinate>knee_angle_r</z_coordinate>
</MovingPathPoint>
hope that helps,
-james
You can define the x,y,z locations of a moving point by independent simmsplines. A good example of this is in the gait2392 model (rect_fem_r-P3).
__________________________________________________________________________________________________________
<MovingPathPoint name="rect_fem_r-P3">
<location> 0.0617576 0.020984 0.0014</location>
<body>tibia_r</body>
<x_location>
<SimmSpline>
<x> -2.0944 -1.99997 -1.5708 -1.45752 -1.39626 -1.0472 -0.698132 -0.526391 -0.349066 -0.174533 0 0.00017453 0.00034907 0.0279253 0.0872665 0.174533 2.0944</x>
<y> 0.0155805 0.0179938 0.0275081 0.0296564 0.0307615 0.0365695 0.0422074 0.0450902 0.048391 0.0534299 0.0617576 0.0617669 0.0617762 0.0633083 0.066994 0.0733035 0.0573481</y>
</SimmSpline>
</x_location>
<x_coordinate>knee_angle_r</x_coordinate>
<y_location>
<SimmSpline>
<x> -2.0944 -1.99997 -1.5708 -1.45752 -1.39626 -1.0472 -0.698132 -0.526391 -0.349066 -0.174533 0 0.00017453 0.00034907 0.0279253 0.0872665 0.174533 2.0944</x>
<y> 0.0234116 0.0237613 0.0251141 0.0252795 0.0253146 0.0249184 0.0242373 0.0238447 0.0234197 0.0227644 0.020984 0.0209814 0.0209788 0.0205225 0.0191754 0.0159554 -0.0673774</y>
</SimmSpline>
</y_location>
<y_coordinate>knee_angle_r</y_coordinate>
<z_location>
<SimmSpline>
<x> -2.0944 0.1745</x>
<y> 0.0014 0.0014</y>
</SimmSpline>
</z_location>
<z_coordinate>knee_angle_r</z_coordinate>
</MovingPathPoint>
hope that helps,
-james
-
Nicolas Eydieux
- Posts: 12
- Joined: Tue Dec 10, 2013 3:20 am
Re: Several control coordinates for a moving path point.
Hi James,
Thank you for your quick answer. Actually, I have already defined my Moving path point by independent simmplines. However, this point have to move according to two different coordinates. In my example, the x,y and z locations of one of deltoid's path points have to change first according to shoulder elevation. Then, when this position is optained, x,y and z locations would be change according to shoulder rotation.
In the Stanford VA upper limb model, they used two bodies without mass as a solution (DELT2_pt2a and DELT_pt2), with Coordinate Coupler Constraints. Indeed, the DELT_pt2a translates in humerus frame according to shoulder elevation and the DELT_pt2 translates in DELT2_pt2a frame according to shoulder rotation. Then the fixed path point is defined in DELT2_pt2, which is defined in DELT2_pt2a. Nevertheless, OpenSim tools crashes because of these sort of bodies without mass as you specified in the topic :
"Stanford VA upper limb model" : Problem with tools.
Perhaps there is no solution for this problem.
In any case, thank you very much for your answer,
Nicolas.
Thank you for your quick answer. Actually, I have already defined my Moving path point by independent simmplines. However, this point have to move according to two different coordinates. In my example, the x,y and z locations of one of deltoid's path points have to change first according to shoulder elevation. Then, when this position is optained, x,y and z locations would be change according to shoulder rotation.
In the Stanford VA upper limb model, they used two bodies without mass as a solution (DELT2_pt2a and DELT_pt2), with Coordinate Coupler Constraints. Indeed, the DELT_pt2a translates in humerus frame according to shoulder elevation and the DELT_pt2 translates in DELT2_pt2a frame according to shoulder rotation. Then the fixed path point is defined in DELT2_pt2, which is defined in DELT2_pt2a. Nevertheless, OpenSim tools crashes because of these sort of bodies without mass as you specified in the topic :
"Stanford VA upper limb model" : Problem with tools.
Perhaps there is no solution for this problem.
In any case, thank you very much for your answer,
Nicolas.