Dymola model not initializing with auxiliary variables turned off in output - modelica

I am trying to run a model in Dymola 2019 FD01 with auxiliary outputs turned off (to improve simulation speed). I've also set the flag:
Advanced.AutoRemoveAuxiliaries = true;
When I try to run the model, I get:
Error: Integrator failed to start model.
I am able to run the same model with Auxiliary Variable outputs turned on and the flag set to true.
I was wondering if someone else had this issue before and how to go about troubleshooting this problem.
The dymola user manual states this about the flag:
Advanced.AutoRemoveAuxiliaries - Removes code for auxiliary variables that neither influence the simulation state nor the outputs. This improves performance a bit. If the auxiliary code is used to assert correct behaviour or to generate external outputs, that code will not be run.
I am able to run some other models which have assert statements with the same settings (aux outputs off), so it seems like there is something else essential to the model removed during initialization.
I am trying to replicate the issue with a simple model but i have no idea where to even start.

Related

Update S-function Parameters in Fast Restart

I have read the Mathworks documentation carefully and tried to find a solution on forums as well. However, I have not been able to find a solution to my problem yet.
I am using Matlab/Simulink to simulate the dynamics of a vehicle, which picks up an object during operation. The way I am planning to do this is to:
Simulate the motions of the vehicle by itself at the start of the simulation;
Stop the simulation, save the final state, update the model parameters (so that they now represent the vehicle and the object)
Initialize the simulation again starting from the end time of the previous run and using the previous final state as input state to the new simulation.
To do this, I have been using the options FastRestart, SaveFinalState, SaveCompleteFinalSimState and update. Unluckily, the simulation runs seamlessly, but the model parameters are not updated.
The dynamics of the vehicle and vehicle+body are modelled by the same C-coded S-function. This function receives the parameters of the dynamic equations (e.g. inertia, damping, etc.) as parameters to the S-function block. I think this is the main problem with my approach: even though I run the update command, the S-function does not recognize the update of the parameters in the workspace. Do I need to recompile it? I guess that is not feasible under Fast Restart mode, is it?
Any advise is really appreciated! Thank you!
I have a similar issue to this in a different situation. Trying to update the initial state target of a revolute joint, the fast restart option does not change the property.
I have had some luck updating the model in fastrestart with other parameters, however, using:
set_param('Model_Name','TunableVars','Variable Name')
Not sure if this will help in your situation, perhaps saving the final state as a variable and having the respective variables as initial parameters.

step by step simulation in command line for Matlab Simulink model

I want a solution for command line implementation for Matlab Simulink. In simulink model there is simulation switch called "step forward". With this I am able to run step by step and able to see the outputs in scope for each sample time.
I am also able to change some inputs for constant input blocks at any sample period time. However, I want to do this in command line, because I have a huge model and I want to reuse this model verification script.
I am able to do some thing like this using "sim" command. But the sim command is just simulating the entire model at once, and I could not observe/change the intermediate outputs/inputs. The "sim" command with a certain stop time is running for certain sample periods, but later if I give the next "sim" command, it is running from the beginning and not starting from where it stopped. But, is there any exact Matlab command to step and pause (for one sample period time) the simulation, like that in simulink gui.
You want to use SimState to save the states of the model at the end of one simulation, and restore them at the beginning of the next simulation. How to do this is described in the documentation under Save and Restore Simulation State as SimState.
You cannot make any structural changes to the model (e.g. add or remove block) between each call to sim. There are also a few blocks which don't support SimState, see the documentation for more details. Note that this is for the latest release (R2015a), more and more blocks were added to support SimState over the past few years, so you want to check the release notes depending on the release you are using.
You can try this:
sldebug('gcs');
you are now in debug mode, you can type in help to get an overview of the available commands. To run through the model type in:
next
Each time you type next, you move the simulation one step forwards.
The following link will provide you with further details on how stepping through a simulation works.
http://www.mathworks.com/help/simulink/ug/how-stepping-through-a-simulation-works.html
For more details on using the debugger to run through the simulation step by step you can go to:
http://www.mathworks.com/help/simulink/ug/running-a-simulation-step-by-step.html

Managing multiple anylogic simulations within an experiment

We are developing an ABM under AnyLogic 7 and are at the point where we want to make multiple simulations from a single experiment. Different parameters are to be set for each simulation run so as to generate results for a small suite of standard scenarios.
We have an experiment that auto-starts without the need to press the "Run". Subsequent pressing of the Run does increment the experiment counter and reruns the model.
What we'd like is a way to have the auto-run, or single press of Run, launch a loop of simulations. Within that loop would be the programmatic adjustment of the variables linked to passed parameters.
EDIT- One wrinkle is that some parameters are strings. The Optimization or Parameter Variation experiments don't lend themselves to enumerating a set of strings to be be used across a set of simulation runs. You can set a string per parameter for all the simulation runs within one experiment.
We've used the help sample for "Running a Model from Outside Without Presentation Window", to add the auto-run capability to the initial experiment setup block of code. A method to wait for Run 0 to complete, then dispatch Run 1, 2, etc, is needed.
Pointers to tutorial models with such features, or to a snip of code for the experiment's java blocks are much appreciated.
maybe I don't understand your need but this certainly sounds like you'd want to use a "Parameter Variation" experiment. You can specify which parameters should be varied in which steps and running the experiment automatically starts as many simulation runs as needed, all without animation.
hope that helps
As you, I was confronted to this problem. My aim was to use parameter variation with a model and variation were on non numeric data, and I knew the number of runs to start.
Then i succeed in this task with the help of Custom Variation.
Firstly I build an experiment typed as 'multiple run', create my GUI (user was able to select the string values used in each run.
Then, I create a new java class which inherit from the previous 'multiple run' experiment,
In this class (called MyMultipleRunClass) was present:
- overload of the getMaximumIterations method from default experiment to provide to default anylogic callback the correct number of iteration, and idnex was also used to retrieve my parameter value from array,
- implementation of the static method start,
public static void start() {
prepareBeforeExperimentStart_xjal( MyMultipleRunClass.class);
MyMultipleRunClass ex = new MyMultipleRunClass();
ex.setCommandLuneArguments_xjal(null);
ex.setup(null);
}
Then the experiment to run is the 'empty' customExperiment, which automatically start the other Multiple run experiment thru the presented subclass.
Maybe it exists shortest path, but from my point of view anylogic is correctly used (no trick with non exposed interface) and it works as expected.

Simulink model rebuilds every time when no changes are made

I've been having this issue since I started using this Simulink model. No matter what I try, Simulink rebuilds the model every time I run it. I've taken a look at the checksums using the following procedure:
>> [cs1, cs1det] = Simulink.BlockDiagram.getChecksum(<model name>);
>> (Here I hit run on the model without changing anything)
>> [cs2, cs2det] = Simulink.BlockDiagram.getChecksum(<model name>);
>> cs1 == cs2
1
1
1
1
Why would Simulink rebuild the model if the checksums are the same? I did create another model with some simple logic in it and after compiling once I was able to run it multiple times without Simulink recompiling it.
Additionally, when I hit run when in Rapid Accelerator mode I notice that an asterisk pops up next to the model name in the title. Since this means that the model has unsaved changes, could running it cause any changes to be made? I've checked the callback methods and there's nothing being run when the sims starts (in fact there's nothing in any of the callback methods).
Is there some kind of basic compilation / initialization / build that Simulink runs through before it runs every time? I'm trying to run my model in Rapid Accelerator mode without having it recompile since it takes roughly 45 minutes to compile every time.
Have I overlooked some configuration parameter of the model? Is there some global MATLAB/Simulink variable I need to change?
Is it building or is it updating?
Typically, when you hit the Run button, MATLAB has to propagate signals, check your model for errors, initialize variables . . .
It may seem like building, but to actually confirm it is building, check to see of you have yourmodelname.c file in the folder.
Also check File Menu preferences, and go through the functions there and see if something is getting called.
Could you try to set Configuration Parameter -> Code Generation -> Interface -> Code replacement library to None (In case that your demand is not related to GNU library ...) on reference model?
By the way, it is working for me.

Is is possible to programmatically play a Simulink model and measure its states?

I am looking to set up a test set for an existing Simulink model. Ideally I could take full control of the model, explicitly stepping it and measuring the state of any signal on any bus in the model.
As might have been gleaned, this is the precursor of a unit testing system for the model. Being so, I can't really justify changing the model to suit the test, the test must accommodate the model as-is.
The furthest I've got so far is using load_model() to return a handle to the model. From there there seems to be a quite obscure set of functions for accessing the model. I can't see any that relate to accessing states and can't see any further commands that relate to accessing a loaded model.
The easiest way is to use the Data Import/Export function within the Simulink Preferences.
Set the checkbox States and it will store every state of your system for every time step in your workspace, also when you pause the simulation or execute it step by step.
Be aware not to set Save simulation output as single object, in this case the access would be more complicated and you need to follow the instructions here.
To add to the other answer, you probably want to check this page in the documentation: Control Simulation Using the set_param Command. Of interest are the following commands:
set_param(<model_name>, 'SimulationCommand', 'start')
set_param(<model_name>, 'SimulationCommand', 'pause')
set_param(<model_name>, 'SimulationCommand', 'WriteDataLogs')
set_param(<model_name>, 'SimulationCommand', 'continue')
Replace <model_name> by the path to your model file.