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Hi,

I need to build a multibody model in MapleSim 6.4 in which with few global parameters I can describe all the other parameters. In other words the final user will enter this few parameters, that are coordinates of specific points, and then the model will calculate all the relative distances on the base of those coordinates.

The problem is that if I apply trigonometric function and square root (like in the screenshot) the model is not calculating any value. Is it possible to make those calculculations?

 

this is the model (don't worry about the nonsense plots, it's because it's not ultimated):

DWS.msim

The calculation are the in the UpperFrame Subsystem.

 

Thanks.

 

Hi,

I need to build a multibody model in MapleSim 6.4 in which with few global parameters I can describe all the other parameters. In other words the final user will enter this few parameters, that are coordinates of specific points, and then the model will calculate all the relative distances on the base of those coordinates.

The problem is that if I apply trigonometric function and square root (like in the screenshot) the model is not calculating any value. Is it possible to make those calculculations?

 

this is the model (don't worry about the nonsense plots, it's because it's not ultimated):

DWS.msim

 

 

Thanks.

 

Zero Free Length Spring...

October 02 2014 Alamdari 5

Hello,

I am going to model a statically balanced mechanism by using zero free length spring in MapleSim. In path Multibody> Force and Moments>, there is a Translational Spring and Damper which I can use, and I just enter zero length for spring unstreched length. In physical model, zero free length spring never get zero length because of the existing coils, but in MapleSim it reaches zero during simulation. Does anyone here know how can I model zero free length springs?

Thanks

Hi,

I am trying to plot only the real part of the values obtained from the MapleSim model.  Probably there is a Modelica function to get only the real part of the values, but I am unable to find it. Could you please have a look at the code and let me know what I should do to solve this problem?

Best

Onder

 

The code is: (I want to plot the real part of R2)

 

model IKTest

parameter Boolean switched = false;
parameter Modelica.SIunits.Length L1 = 0.100;
parameter Modelica.SIunits.Length L2 = 0.102;
parameter Modelica.SIunits.Length L3 = 0.5;
//parameter Real c; //Complex number
//parameter c;

Modelica.Blocks.Interfaces.RealInput u[3]
annotation (Placement(transformation(extent={{-140,-20},{-100,20}},rotation=0)));
Modelica.Blocks.Interfaces.RealOutput y[3]
annotation (Placement(transformation(extent={{90,-10},{110,10}},rotation=0)));

Real Tx = u[1];
Real Ty = u[2];
Real Tz = u[3];
Real R1 = y[1];
Real R2 = y[2];
Real R3 = y[3];

equation

R1=atan(Ty/Tz);
R2=(acos((L1^2+L2^2-(sqrt(Tx^2+Ty^2+Tz^2))^2)/(2*L1*L2)));

//2*Modelica.Math.asin(1.0)
//R3=R2.re;

annotation (uses(Modelica(version = "3.1")));
end IKTest;

Hello,

I have a little question about the display of the kinematic joints which are usually in red.

I didn't know why the kinematic joints have disappeared and I don't know how to display them again.

Do you have an idea about the button I have to use so as to display the kinematic joints.

Thanks for your help.

Hello,

In my model, it seems that I have parameters which are not evaluated.

Indeed, I'm not sure that the parameters defined with relations as you can see in the printscreen are evaluated.

 

One point which helps me to debug my model is to follow the evaluation of the construction of my model with the 3D visualization.

Questions :
1) How can I do to be sure that my parameters are evaluated ?

2) Is it possible to launch the update of the 3D visualization even if I still have some bugs in my model ?

Thank you for help.

Hello,

In a subsystem, i defined parameters like this in the "parameters" area :

 

In the "diagram" area, the parameters are not updated because i see this panel :

 

Do you know why the parameters are not updated (possibly only on visualization) ? And if yes, how i can do to visualize in this last panel the value of the parameters updated ?

Thanks a lot for your help

Hi,

 

I want to calculate a new position (X,Y,Z) for a cartesian model with 3 points (dX,dY,dZ) but  I got a problem, my point is a parameters, so I can't change it in the simulation in real time with a Input signal on the components. Does It exist a solution for convert a parameters to a variable to get a Input signal?

Exemple of my calcul:

eq:= [x(t)= dx+sin(dy/dz), y(t)=dy+20,z(t)=dz]

 

Thanks!

Hello all,

When I try to do this example, in the multibody analysis, http://www.maplesoft.com/products/maplesim/ModelGallery/detail.aspx?id=137

Thats already written :

 

but when I enter theses formulas(mModel & MB), that write instead of the example:

"Analyzing system..."
"Performing constraint analysis..."
"The system has 2 degree(s) of freedom. It is modeled using 2

generalized coordinate(s) coupled by 0 algebraic constraint(s\

And I have no result if i do vPosCons := MB:-GetPosCons(); . What am I doing wrong?

Thank you

I have some data for a model in MapleSim that I would like to use a time look up table with.  I've found that the two options for interpolation are linear and 1st derivative, but the data was intended to be interpretted as piecewise constant.  Is there any way to acheive this option in MapleSim?

Hi

I tried to import the modelica library Buildings1.6 from the modelica website and get always the error "Nothing found in the modelica library". 

Is it possible to import modelica libraries? 

Thank you very much

Natural Frequency...

March 24 2014 md7007 15

Hi

i want to calculate natural frequencies with MapleSim, but i can't. is it possible to calculate natural frequencies with MapleSim or not? if the answer is positive, how i can make it? Thnx

Hi MaplePrimers!

I have a simulation in MapleSIM, exported as a compiled procedure in maple using -LinkModel(), and -GetCompiledProc.

I'm trying to do parameter estimation on my MapleSIM model.  Within a optimization scheme, I call the MapleSIM model, and it will output a curve.  Using a least squares method, I compare this measurements to synthetic experimental data (I know the actual values), and generate an objective function.  The optimization algorithm will try different parameter values, and try to minimze the objective function.  When the curves are exactly the same, the objective function will be zero.

The problem I am having is certain parameter sets will cause the model to require very small steps.  I wish to put a timeout on these experiments, because speed is important.  However, I would also like to see the results up to the point of requiring very small steps.  For timeout, I was using code along the lines of:

out:= timelimit(30,cProc(params = PData)); #simulate with 30s limit

where PData are the parameter guessses, and cProc is the compiled MapleSim model.

I would like 'out' to be assigned whatever the results were after 30 seconds, even if the model had not finished integrating.

 

Thanks in advance for any help!

Hi,

Does Maplesim allow hardware integration such as a joystick so that I can feed in joystick commands (via USB or serial) from the computer and then control my Maplesim model in the virtual space? Suggestions?

 

Thank you.

Hi,

I'm currently working on a manipulator model in Maplesim and will import CAD attachments to each of the links. The Solidworks model, once imported to Maplesim, is not located in the same position as the Maplesim part but is offset by X,Y,Z. The scaling is also off. Is there some way to align the CAD to the component instead of trial and error?

Thank you.

 

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