# Question.

To, AnyBody tech.

I fully satisfy with your Biomechanic Tool.

But, Sometimes, I have some problem with that.

The point is that I want to know about putting external force to

But, there is only simply load mode, I guess.

I couldn’t find code putting forces which have some time duration.

If I want to see situations like punching or kicking, It needs an
impulse force which has some time interval.

I want to know how I create impulse force or impulse load to model
and

how I can analyze resultant position or posture changes from impulse
force on which I want to exert.

Hi Hong?

Welcome to the group

It is possible to use the an interpolation function for creating a force
impulse

So if you write something like this

AnyFunInterpol force =

{

`````` Type = BSpline;

BsplineOrder = 4;

T ={0,1,2,3}/10 ;  //time vector

Data = {{10,20,20,20}};  //force vector

//FileName = "";

//FileErrorContinueOnOff = Off;
``````

};

AnyForce3D force3d =

{

`````` F = {.force(Main.Study.t),0,0};  //x force function in time, force
``````

function could also be in 3dâ€¦

`````` //Flocal = {0, 0, 0};

AnyRefFrame &ref = some node where the force should be applied
``````

};

Concerning the second question: how it is possible to see posture changes to
force impact? the simple answer is that this not possible. These models are
based on inverse dynamics which means that the load is supplied as input.
This means that the motion will remain unchanged when any load is applied.

If the force impulse is very short you will have to used very small time
steps to capture the effect of the pulse.

There is a possibility to see the effect of the loads though if you add an
extra optimization loop around the analysis. This kind of analysis requires
some experience in using the system. These short abstract, shows an example
of such an analysis where the motion of the ankle joints has been optimized,
in a bicycle motion

http://www.anybody.aau.dk/pdf/inverse.pdf

Best regards

SÃ¸ren, AnyBody Support

From: anyscript@yahoogroups.com [mailto:anyscript@yahoogroups.com] On Behalf
Of mrhong87
Sent: 25 September 2008 13:19
To: anyscript@yahoogroups.com
Subject: [AnyScript] Question.

To, AnyBody tech.

I fully satisfy with your Biomechanic Tool.

But, Sometimes, I have some problem with that.

The point is that I want to know about putting external force to

But, there is only simply load mode, I guess.

I couldn’t find code putting forces which have some time duration.

If I want to see situations like punching or kicking, It needs an
impulse force which has some time interval.

I want to know how I create impulse force or impulse load to model
and

how I can analyze resultant position or posture changes from impulse
force on which I want to exert.

[Non-text portions of this message have been removed]