Applying an external force
Posted: Mon Jun 29, 2015 9:03 am
Hello!
I am working with an upper extremity model, and I want to apply a force that will constantly be applied at the center of the hand for a forward dynamic simulation. Without using motion capture systems and force plates to generate a motion or storage file that can be applied to the forward dynamic simulation, is there any way to write in this external force into my model? I have played around with a prescribed force, but I either don't have the code correct, or it is not what I want to do.
This is what my code looks like:
<PrescribedForce name="prescribedF">
<!--Flag indicating whether the force is disabled or not. Disabled means that the force is not active in subsequent dynamics realizations.-->
<isDisabled>false</isDisabled>
<!--Name of the body the force is applied to.-->
<body>hand</body>
<!--Flag indicating whether the point (specified in pointFunctions) is in global frame.-->
<pointIsGlobal>false</pointIsGlobal>
<!--Flag indicating whether the quantities (specified in force/torqueFunctions) is in global frame.-->
<forceIsGlobal>true</forceIsGlobal>
<!--Three functions describing the force to be applied.-->
<FunctionSet name="forceFunctions">
<forceFunctions>
<function>
<Constant name="forceX">
<value>-100000</value>
</Constant>
</function>
<function>
<Constant name="forceY">
<value>0</value>
</Constant>
</function>
<function>
<Constant name="forceZ">
<value>0</value>
</Constant>
</function>
</forceFunctions>
</FunctionSet>
<!--Three functions describing the location at which the force is applied.-->
<FunctionSet name="pointFunctions">
<pointFunctions>
<function>
<Constant name="pointX">
<value>0</value>
</Constant>
</function>
<function>
<Constant name="pointY">
<value>0</value>
</Constant>
</function>
<function>
<Constant name="pointZ">
<value>0</value>
</Constant>
</function>
</pointFunctions>
</FunctionSet>
</PrescribedForce>
I would prefer to stick with writing this on xml.
Thanks!
Clarissa
I am working with an upper extremity model, and I want to apply a force that will constantly be applied at the center of the hand for a forward dynamic simulation. Without using motion capture systems and force plates to generate a motion or storage file that can be applied to the forward dynamic simulation, is there any way to write in this external force into my model? I have played around with a prescribed force, but I either don't have the code correct, or it is not what I want to do.
This is what my code looks like:
<PrescribedForce name="prescribedF">
<!--Flag indicating whether the force is disabled or not. Disabled means that the force is not active in subsequent dynamics realizations.-->
<isDisabled>false</isDisabled>
<!--Name of the body the force is applied to.-->
<body>hand</body>
<!--Flag indicating whether the point (specified in pointFunctions) is in global frame.-->
<pointIsGlobal>false</pointIsGlobal>
<!--Flag indicating whether the quantities (specified in force/torqueFunctions) is in global frame.-->
<forceIsGlobal>true</forceIsGlobal>
<!--Three functions describing the force to be applied.-->
<FunctionSet name="forceFunctions">
<forceFunctions>
<function>
<Constant name="forceX">
<value>-100000</value>
</Constant>
</function>
<function>
<Constant name="forceY">
<value>0</value>
</Constant>
</function>
<function>
<Constant name="forceZ">
<value>0</value>
</Constant>
</function>
</forceFunctions>
</FunctionSet>
<!--Three functions describing the location at which the force is applied.-->
<FunctionSet name="pointFunctions">
<pointFunctions>
<function>
<Constant name="pointX">
<value>0</value>
</Constant>
</function>
<function>
<Constant name="pointY">
<value>0</value>
</Constant>
</function>
<function>
<Constant name="pointZ">
<value>0</value>
</Constant>
</function>
</pointFunctions>
</FunctionSet>
</PrescribedForce>
I would prefer to stick with writing this on xml.
Thanks!
Clarissa