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Hi everybody,

is it possible to define an homokinetic joint in MapleSim for multibody modeling? How can I do that?

 

thanks.

Hello,

Is it possible to hide the geometry linked to the center of gravity and masses in the implicit geometry and keep only the kinematic joint.

If yes, may you explain how ? For the moment, I only manage to show/hide all the element of the implicit geometry. 

I use MapleSim 6.4.

Thank you for your help.

 

Hi,

I used to use windows 32 bit, but I have 64 bit windows now. I installed the MapleSim 6.4 and Maple 18 and try to run the simulations that I created with the 32 bit windows. I have this error 'Unable to compile (rc=1), please try again, and if that fails verify your Windows compiller installation'. Could you please let me know what should I do to eliminate this problem?

Best

Onder

Hello,

I would like to copy/ paste my maplesim model in microsoft visio.

The idea is to create a vectorial illustration for presentation.

I manage to do this with simulink but not with Maplesim.

Apparently, when I go in visio, there is no possibility to copy like a metafile.

Is there a possibility to copy the object of a Maplesim model in a software like visio or illustrator so as to be able to create vectorial illustration for presentation ?

Thank you for your help.

Updates are now available for both Maple 18 and MapleSim 6.4. 

Maple 18.02 contains improvements to many areas, including:

  • Rendering of 2-D plots
  • Help pages and examples
  • Interactive components
  • MATLAB 2014a support
  • Math engine: Laplace transforms, complex floats, simplify
  • Matrix import
  • Context menus
  • Typesetting
  • Memory management
  • OpenMaple API
  • Physics (details in comments)

To get this update, you can use Tools>Check for Updates from within Maple, or visit Maple 18.02 Downloads. (But depending on when you read this, Check for Updates may not have kicked in yet. If it doesn't find anything, wait until tomorrow morning and try again.)

For those users who haven't upgraded to MapleSim 7 yet, MapleSim 6.4.01 includes:

  • Efficiency improvements to the simulation engine, taking advantage of enhancements in Maple 18.02
  • Improvements to C code generation for model export
  • Improved handling of indexed variables when generating Modelica code

In MapleSim, use  Help>Check for Updates or visit MapleSim 6.4.02 Update. Note that MapleSim 6.4.02 is compatible with Maple 18.02.  Upgrade your Maple 18 installation to Maple 18.02 before installing this MapleSim update.

eithne

Hello,

I am quite new on Maple and Maplesim. A co-worker and I are evaluating a demo version (Maple 18 with Maplesim 7) for a possible purchase in 2015. For the project my collegue and I are working on, we need to detect when a signal becomes zero in order to switch between two options. We were trying to do this using the "Change" or "Boolean Change" components (the difference between those two is not really clear to us). Correct me if I am wrong, but those components should detect when a boolean signal has a change in value (both rising or decreasing) and in that case the output should become TRUE, while otherwise is FALSE.

The problem is that the component work if a "Terminate" is connected, but the output is always FALSE in any other case.

At the bottom we are attaching a file with two very easy examples.

In the first one the input of the "Boolean Change" component is a "Boolean Pulse". We compared also the output of the "Change", "Rising Edge", and "Edge with Initial Value" components. We were expecting istantaneous pulse with frequency equal to that of the boolean pulse, or its half for the Edge block. On the contrary the output of all the components stays zero (thus FALSE) for the whole simulation.

The second example use the output of a "Greater Threshold" component to enter the "Boolean Change", whose output is used to trigger a "Switch", whose output is in turn used as an input for the "Greater Threshold" component. The expected result is to have the "Switch" output to alternate the two inputs, instead it keeps the second one (thus the input for the switch is always FALSE).
The feature we need is more similar to this second output, but we don't understand what we are doing wrong or if there is another way to do it.
Thank you in advance
Irene

test_change.msim

Hey guys,

i'd like to create a custom component for maplesim. I opened the template in maple18 and defined the following equations:

eq := [p(t) = p__0+rho*g*h(t), Q(t) = A*(diff(h(t), t)), L(t) = 100*h(t)/h(0)]

These equations describes a tank with a liquid in it. Now I tried to define a function L(t) (above) that gives the level of the tank in percentage. Therefore I need the initial height value at t=0. The function defined above (h(0)) does not work, cause maple tells me that the function does not exist.

Any hint how to get an initial value or a value at t=0? Or maybe another way to solve my problem?

Hopefully I described right. :-)

Best regards

Christian

We have just released a new version of MapleSim.

MapleSim 7 makes it substantially easier to explore and validate designs, create and manage libraries of custom components, and use your MapleSim models with other tools. It includes:

  • Easy model investigation. A new Results Manager gives you greater flexibility when it comes to investigating your simulation results, including the ability to compare simulation runs on the same axes, instantly plot both probed and unprobed variables, and easily create custom plots.
  • Convenient library creation. With MapleSim 7, it is significantly easier to create, manage, and share libraries of custom components.
  • Improved Modelica support. MapleSim 7 expands the support of the Modelica language so that more Modelica definitions can be used directly inside MapleSim.

We have also updated and expanded the MapleSim 7 family of add-on products:

  • The new MapleSim Battery Library, which is available as a separate add-on, allows you to incorporate physics-based predictive models of battery cells into your system models so you can take battery behavior into account early in the design process. 
  • The MapleSim Connector for FMI, which allows engineers to share very efficient, high-fidelity models created in MapleSim with other modeling tools, has been expanded to support more export formats for co-simulation and model exchange.

See What’s New in MapleSim 7 for more information about these and other improvements in MapleSim.

 

eithne

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.

 

Hi everyone,

I have to create a double wishbone suspesione model that can be edited by different users, only introducing some reference point values (called Hard Points). So I need some tool that, in some way, passes from the entered reference point values to the actual values of the bodyframes link. 

I found an already done model (from this link) that seems to be perfect to me because contains an attached Maple document that does exactly what I need working on the base of symbolic parameters applied to the MapleSim model. Now my problem is that I need to deeply change the model and so having the possibility to change the parameter set and insert for example nex parameters. But when I try to do that some problems come out with the Maple document: the syntax of the nex parameter set is different from the default (in the sense of already built in the model I downloaded) one and there are some syntax errors. Below I'll put a screenshot of the error.

 

under the XData code line, you can also see the syntax of one of the parameters that is very long and complicated: below I'll insert another image from which it can be seen the syntax with the original parameter set.

Now if you another idea for solving the initial problem, that would be great! Instead do you have an idea on how to fix the problem with the downloaded model? In my opinion there is a different MapleSim version problem, in the sense that could be thatn the model I downloaded has been done in another MapleSim version in which the parameter set syntax was different.

Hello,

I could obtain the simulation of my multibody with kinematic closed chain (CKC).

However, it seems that from a specific time (around 12s) in my model I believe that I have some numerical instabilities. Indeed, I could compare my simulation results with another mulbody software. I obtain the same simulation until 12s and after in MapleSim, it appears many perturbations as you can see on the figures belows.

So, I think that I tune the numerical solver. This numerical solver must solve DAEs equations since my model contains 4 kinematic closed loops.

If i read correctly the help menu, there are the following methods to solve the DAEs :

- use specific DAE numerical solver (3 differents solvers are used : ck45 method, RKF45 method and Rosenbrock method

- use reformulation equations techniques (Baumgarte, Projection) which can be associated (I believe) with a classic solver like (RK4).

For the moment, I have obtained my results with the rosenbrock solver with error absolute : 1.0*10^(-4) and eror relative :error absolute : 1.0*10^(-4) 

Do you have some ideas or advices so as to find a better method to solve my multibody systems with kinematic closed loops ? This method should  prevent the creation of numerical instabilities.

Thanks a lot for your help

 

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;

with(plots):

a:=polarplot(3-3*cos(theta),theta=0..2*Pi):

c:=plot((3*sqrt(2)+3)/2 + ((-3*sqrt(2))/(-3*sqrt(2)-6))*(x+((3*sqrt(2)+3)/2)),x=-10..10):

display(a,c,view=[-10..10,-10..10]);

 

a:= is the polar plot of the cardiod (3-3cos(theta)


In order to plot the tangent line to the cardiod in theta= 3Pi/4, I find the point (x,y) in rectangular coord x=(3-3cos(theta)cos(theta) and y=(3-3cos(theta)sin(theta); then I find the derivative of dx/dy=

[(3-3*cos(theta)*cos(theta)+sin(theta)(3sin(theta)]/[-(3-3cos(theta)sin(theta)+cos(theta)(3sin(theta)]and from here I get the slope.So I can plot c:= tangent line to the cardiod in 3Pi/4.

How can I avoid having to convert everyting to rectangular coords, and plot the tangent line in polars?

 

 

Hello,

I have a question concerning the initial conditions.

One interest of MapleSim is to enable to model a multibody systems with different kinds of coordinates : namely relative and absolute coordinates.

For a complex system, it seems to me that the determination of the initial position is not an easy task.

Consequently, I wonder if it is possible to determine the initial positions for the system in absolute coordinates thanks to the knowledge of the initials positions in relative coordinates.

In other words, I have already determined the initial positions of my system in relative coordinates but as I would like to simulate my system with absolute coordinates. I wonder if I can have a process to deduct the initial positions for the absolute coordinates for the initial positions in relative coordinates.

Thanks a lot for your ideas and help.

Hello,

In my model, in order to better follow a analytical study, i would like to make some calculations with my paramters.

For example, I have defined :

xa=1

ya=2

R=sqrt(xa²+ya²)

I would define R in the parameters area so as to use it for some definitions in the definition of body (i use especially maplesim for multibody systems.)

How is it possible to define parameters thanks to relations ?

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