I am making simulations for long times and I need to check the output when the simulation is continuing. Another reason is that I am doing real-time simulation so I want to see the output in real-time as well.
That would be perfect if OpenModelica creates an output file during the simulation so that I can read and plot it using 3rd party tools, maybe Python.
So far as I know, OpenModelica creates output file only at the end of the simulation. Is there a way to create an output file using a Modelica function? Assuming something like this:
when sample(0,100) then
writeOutput();
end when;
Related
My problem is that I am running a sweep study with some parameters. I change them in MATLAB and then run a simulation in MATLAB with the sim command. The simulation in SIMULINK contains an external software component from COMSOL with an FEM behind it. In some cases where the configuration is unfavorable (rapid changes in the feedback loop of the controlled system), the FEM tool is not able to converge in finite time, resulting in an error after a few simulation seconds/minutes/hours. The simulation command is inside a try-catch section to avoid that the program is stopped and the next study step starts to process the acquired data.
The problem is that in case the simulation has a convergence problem, the data generated up to this error is not sent to the workspace, but would be valid, and so I cannot find out from the data what was the reason for the convergence problem.
As additional information, I have been using the ToWorkspace block to send the data to my workspace where I do my post processing, and that works fine when the simulation is complete.
If any of you have any ideas on how to solve this problem, maybe you can help me.
Thank you in advance.
I'm new to Matlab/Simulink but have a requirement to interface with a Simulink model from a piece of software.
At the moment I have created a simple Simulink function 'Inc' which has 1 input to an addition block with a constant 1 and an output. I have used To/From Workspace blocks and can run the simulation over a fixed time using a time/value vector input, such as simin = [0,0;5,0;5,1;10,1].
What I would like to do is run my model continuously? Reading Workspace values in real-time rather than a pre-defined time based vector?
I can't see how to set this up? Can Matlab/Simulink do this?
To summarise, I would like simin and simout to be single values i.e. simin = 1, then with the model running continuously(infinitely) at the next fixed step simout would update to simout = 2. simin changes would be made at the Workspace at varying intervals.
The short answer is you can't (easily) do that, that's not how Simulink works. The MATLAB workspace is read/accessed at the beginning of the simulation and passed to the Simulink engine, and even if the values in the workspace change before the simulation is finished, this is not taken into account by the Simulink model running.
There are ways to work around this, but if you are a novice to MATLAB & Simulink, be aware that these are fairly advanced techniques, and I would advise to familiarise yourself with Simulink first.
Have a look at these similar questions for suggestions of how to do what you want:
Stream data form MATLAB to Simulink
Problem of variable updating in workspace
How Do I Change a Block Parameter Based on the Output of Another Block?
Tuning block parameters at every time step in a simulation
Simulink Signal Viewing using Event Listeners and a MATLAB UI
Obviously, you need to change the simulation end time to Inf or some large number.
I believe that it is possible to transfer MATLAB codes to Simulink. When we program in MATLAB, I know that it will execute from top to bottom line by line. On the other hand, Simulink deals with blocks that are connected to each others. There might be feedback signals. There might be subsystems whose outputs are inputs to other blocks and so on...Suppose we have 3 subsystem blocks connected to each other and the last block's output is fed into the first, which block does Simulink start with?
My question might be a foolish one especially after this long of playing with MATLAB and Simulink but I've not come to know the answer for this yet!
This depends on the actual simulation model. Before the simulation starts, Simulink analyzes the model (which blocks are connected in which direction, are there algebraic loops, etc.). The result is the so-called sorted order of the blocks, which is then used to actually execute the blocks' code.
See the documentation for details.
I'm trying to solve a problem of simulating in real time in Simulink (This is solved) but plotting (real time) in Matlab ?
Details:
I want to be able to run a Simulink simulation (which is running in real time) and be able to turn on / off manual switches while the simulation is happening. This works well when I'm using the built in Scopes in Simulink but now I want to export that data to Matlab in real time as well (To make a custom looking graph).
So is there a way, to export this data (it can be sampled if that is necessary) to Matlab and make a plot that is constantly updating. Meanwhile I can still manipulate the switches in Simulink and influence the simulation manually ?
Simulink is effectively running continuously until I stop it.
Thanks for the help!
There should be some kind of notification going when simulink updates the data to be visualized. Maybe this is the linkdata feature.
Another, worse, solution is the drawnow command to redraw the graphs continously (the latter could be unnescessary costly for you program).
Is there any way I could program the Matlab/Simulink to be able to automatically generate circuits on its own? I am using PLECS blockset (Piece-wise Linear Electrical Circuit Simulation ) embedded in Simulink.
For example, I need to have hundreds of identical block in a single .mdl file, instead of inserting one by one by myself by calling the block which I previously saved in Simulink library, is it possible that Simulink can be programmed to automatically generate hundreds of blocks by itself?
The only way I was told is by "using vectorization for most components. Most components are vectorized if they have a vectorized input signal or if one of their parameter is specified as a vector." However, I could not find any further information/details, appreciate if anyone of you could give opinion on this?
I just want to know if this is possible? Else, I would have to try another approach?
Thanks!
edited on 10 July 2013: Further to my question, I have confirmed with Plexim that there isn't such features ( add_block and add_line) in Plecs (Piece-wise Linear Electrical Circuit Simulation), does anyone know if there is any way I could automate the Plecs model? Appreciate any suggestion...Thanks
You can probably use functions like add_block and add_line to automate the creation of your Simulink model from a library.