WhiteNoise

Clemens Guehmann

45 Reputation

5 Badges

17 years, 29 days

MaplePrimes Activity


These are replies submitted by WhiteNoise

@C_R: I assume the complete standard Modelica library is integrated into MapleSim. Unfortunately, only a portion of the library is usable, which severely limits the use of Modelica models created through textual programming. Many freely available libraries are therefore unusable. My frustration concerns the use of the models to generate noise sequences (https://www.mapleprimes.com/posts/231504-Update-To-Maple-2025-And-Announcing-MapleSim-2025#comment206472). To return to your question: I don't understand why MapleSoft doesn't respond to customer requests and implement the full range of Modelica features. But I think MapleSoft focuses primarily on specific models and products that only run under MapleSim. 

Dear MapleSim developers!

Thank you for the MapleSim update. The new drive models are a good addition to the existing ones. The update to the analysis tools is also excellent. But, no product is perfect.

Even though I criticized a few years ago that there is no direct way to generate random sequences such as Gaussian white noise, I must repeat that today to emphasize the urgency. I don't know of any modelling tool, such as Simulink, Dymola, or SystemModeler, where this isn't possible. The “Gaussian White Noise” model from the model gallery is no longer available. The solution of generating random sequences using the integrated Random Data Generator is static and only of limited use. The random sequence is generated before the simulation and must also be time-limited.

The MapleSim website states that neural networks can be trained with the models. I am convinced that this only works effectively if non-static random sequences can also be integrated into the simulation. This should be sufficient motivation for the developers at Maplesoft to focus on integrating random sequences. That's one reason. I suspect that MapleSim users can provide at least a dozen more arguments. In the hope that randomness will find its way into MapleSim, I wish everyone continued happy and successful simulations.

As an electrical engineer, I'm excited about the ability to use phasors in MapleFlow. Thank you for this great feature. Will this simple way of using phasors be available in Maple as well?

Hello Samir!

Why should I use this complicated formatting when it can be done more simply?

@EngM 

You can use MapleSim models in a Modelica custom component in the following ways: First, as already explained, you implement the connectors. Then you have to find out the model in the Maplesoft library. As an example, I have inserted the simple gain block here: Maplesoft.SignalBlocks.Math.Operators.Gain G1(k=4);
Then the block has to be connected with e.g. the connectors. This is done with the connect command. This is all quite cumbersome. For me, this approach is not so useful because when using the Maplesoft blocks, I prefer to work with subsystems where the connectors can be inserted without problems. I only use the Modelica custom components if I already want to integrate Modelica blocks from other applications or if I only need to create models with the Modelica standard library.

@Samir Khan I am using Windows 11. I have used the File>Print menu. When I create the PDF via File>Export, the printout is OK. Thank you very much for the tip.  The File>Print command should also work, right? 
I am sorry, it is not possible to upload a flow file: 

Best wishes from Berlin

 

Clemens 

Hello, 

thank you for your answer. Unfortunately, the problem is still not solved. My solution seems to be correct in principle because the correct value is determined when replacing the Piecewise function. In this special case, this is possible without any problems using the Heaviside function, but for general cases it does not work. The goal is to finally determine a value of the integration in the correct unit (ampere). With your solution, I do not succeed in determining a specific value. Here is the solution with the Heaviside function. 

restart

 

Definition of current functions with units

"`i__1`(t):=Heaviside(t/(⟦s⟧)-0.01)*3⟦A⟧*cos((2*Pi*t)/(T)):"

"`i__2`(t):=3⟦A⟧*cos((2*Pi*t)/(T)):"

Definition without units

"`i__3`(t):={[[0,t<0.01],[3*cos((2*Pi*t)/(`T__3`)),t>=0.01]]:"

T := 0.2e-1*Unit('s')

plot([i__1(t), i__2(t)], t = 0 .. .1*Unit('s'), color = [blue, red], legend = [i__1, i__2])

 

Calculation of RMS values

RMS__1 := sqrt((int(i__1(t)^2, t = 0 .. T))/T)

1.500000000*(Units:-Unit(A^2*s)/Units:-Unit(s))^(1/2)

(1)

RMS__2 := simplify(sqrt((int(i__2(t)^2, t = 0 .. T))/T))

2.121320344*Units:-Unit(A)

(2)

and now without Units

T__3 := 0.2e-1

RMS__3 := sqrt((int(i__3(t)^2, t = 0 .. T__3))/T__3)

1.500000000

(3)

NULL

Download UnitProblemSecondVersion.mw

Hello,

I had a similar problem for my simulations. Unfortunately, I could not find a direct solution. In my opinion, MapleSim is not compatible here. Your Modelica code runs fine under OpenModelica. But I think you should use the parameter qualifier in front of the variables.

I solved the problem by reading in the data via an Excel file. The solution with the Excel file is not very elegant in my eyes. Perhaps MapleSoft will solve this incompatibility problem one day, or an expert will comment on it? At the very least, it would be helpful to have a direct interface for reading and writing MATLAB data files in MapleSim.

Best wishes

Hello!

Once again, I am pleased to be able to use a new version of MapleSim. Many thanks to the Maplesoft team for the revision. As a user of MapleSim in research and teaching, I would nevertheless like to express my slight disappointment about the further development of the tool from a researcher's perspective. The Modelica functionalities I listed last year that are missing, I would like to briefly list again this time. Noise processes in the signal blocks are still missing. The procedure suggested by Maplesoft, to generate noise via a worksheet, to save it in a CSV file and then to read the data back in via a MapleSim programme, is very inconvenient in my opinion. In addition, only the same data can be used again and again in simulations. Furthermore, I miss the possibility to work with state machines and with synchronized processes (see Modelica Synchronous). Unfortunately, the question from user AjayMenon_20 “How do I implement expandable connectors from Modelica into multi-body simulations in MapleSim?” was not answered. Furthermore, I also lack a perspective on the direction in which the tool is evolving regarding Modelica. Will there be support for Modelica 4.0.0? Nevertheless, I wish you all a lot of success and fun in using or developing MapleSim. 

@TX The Modelica programme is generated automatically via a Maple worksheet. The code is entered into Maple and the interface must then be specified. The code is then generated automatically. 

Congratulations to the new MapleSim version. The new version certainly required a lot of work. Despite the great possibilities MapleSim provides, I have a few suggestions for future versions. Is there a roadmap for future features?  What do I miss most compared to other simulation tools like OpenModelica? 
1. The possibility to comfortably simulate noise signals.
2. The possibility to simulate with state graphs (Modelica StateGraph)
3. The possibility to sample data synchronously ==> Modelica synchronous library. 
4. The possibility to simulate real discrete-time systems. 
In general, from my point of view it is not understandable why the complete Modelica language is not supported.  

Unfortunately, the library is no longer executable under the new version Maplesim 2021. I could not find out the reason. Here is an update now. NoiseX.zip.

Here is an example with Gaussian and uniform distributed noise

 

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