Cardan angle sequences

Hello Anyscript,

I was wondering if anyone could answer my questions. Firstly

  1. what cardan angle sequence does Anybody use in calculating motions?
  2. Is the coordinate system used in calculating joint reaction forces derived from the .C3D file or is it defined by Anybody/modified in Anybody by the user? If I am able to modify it, how would I change in in order to be similar to that of Orthoload?

Any help is much appreciated.

Farooqin

Hi,

  1. If you want to understand how the joint angles of AnyBody human model were defined, then you should see the following files:
    Trunk: ‘…\AMMR\Body\AAUHuman\Trunk\Interface.any’
    Arm : ‘…\AMMR\Body\AAUHuman\Arm\Interface.any’
    Leg : ‘…\AMMR\Body\AAUHuman\LegTD\Interface.any’

  2. In the GaitFullBody example(in AMMR V1.5), all joint reaction forces can be found here : ‘Main.Studies.HumanModel.BodyModel.SelectedOutput’
    And you can see how these values were obtained from these files.
    Trunk: ‘…\AMMR\Body\AAUHuman\Trunk\TrunkSelectedOutput.any’
    Arm: ‘…\AMMR\Body\AAUHuman\Arm\RightArmSimpleMusclesSelectedOutput.any’
    Leg: ‘…\AMMR\Body\AAUHuman\LegTD\RightLegSimpleMusclesSelectedOutput.any’

All the joint reaction force values are expressed with respect to the ‘first’ referenced frame of the joint.
Here is the wiki page about that: http://wiki.anyscript.org/index.php/All_about_Kinetics#How_to_understand_the_reactions_listed_in_a_revolute_joint.3F

And there is a way how to transform these value from local to global or vice versa.

If you see the description of AnyRefFrame class in the reference manual, there are two equations about that.

GlobalVector = (Axes * LocalVector’)’;
GlobalVector = LocalVector * Axes’;

So if you want to transform the joint reactions, then you can use these equations.

I hope this may help you.

Best regards,
Moonki