Update S-function Parameters in Fast Restart - simulation

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.

Related

Usage of timeInState function in Anylogic

So for my project in area of Industrial Engineering, I am making a warehouse simulation and optimization model in software Anylogic. I want to know the time my picker spends in being busy( that is moving) and so I came across this built-in function 'timeInState'. This helps me to determine the total time by picker has spent being 'busy'.
The issue I am facing is that upon calling this function, I am getting no value (0), but my pickers are clearly moving in the model. Maybe the parameters I am giving is not the right way to do it. I was thinking if anyone familiar with this can help me out? . To clarify the function, its meaning and parameter initialization is as below:
double timeInState(ResourceUsageState state) -Returns the time the unit has spent in the given "usage state" so far.
Parameter: state - the state (ResourceUsageState.USAGE_IDLE or ResourceUsageState.USAGE_BUSY)
Thanks for your help !
The timeInState function has nothing to do with state charts but records durations for resources. It is named rather unfortunately...
There is no build-in way to measure state durations (for good reasons ;-) ).
Easiest solution:
create a double variable timer and another timeInStateX
on-enter of your state X, set timer=time()
on-exit of your state X, add the duration as timeInStateX += (time()-timer
Make sure to not accidentally overwrite the timer from elsewhere, though
The timeInState function does work to capture time busy so you must have another problem. You should be calling it similarly to <resource reference>.timeInState(ResourceUsageState.USAGE_BUSY) or (specifying time units) <resource reference>.timeInState(ResourceUsageState.USAGE_BUSY, TimeUnits.MINUTE).
You'll need to give more context to understand why it's not working for you.
You are also seizing and releasing these agents as resources in a ResourcePool right?

Abort execution of parsim

For the use case of being able to abort parallel simulations with a MATLAB GUI, I would like to stop all scheduled simulations after the user pressed the Stop button.
All simulations are submitted at once using the parsim command, hence something like a callback to my GUI variables (App Designer) would be the most preferable solution.
Approaches I have considered but were not exactly providing a desirable solution:
The Simulation Manager provides the functionality to close simulations using its own interface. If I only had the code its Stop button executes...
parsim uses the Simulink.SimulationInput class as input to run simulations, allowing to modify the preSimFcn at the beginning of each simulation. I have not found a way to "skip" the simulation at its initialization phase apart from intentionally throwing an error so far.
Thank you for your help!
Update 1: Using the preSimFcn to set the the termination time equal to the start time drastically reduces simulation time. But since the first step still is computed there has to be a better solution.
simin = simin.setModelParameter('StopTime',get_param(mdl,'StartTime'))
Update 2: Intentionally throwing an error executing the preSimFcn, for example by setting it to
simin = simin.setModelParameter('SimulationCommand','stop')
provides the shortest termination times for me so far. Though, it requires catching and identifying the error in the ErrorMessageof the Simulink.SimulationOutput object. As this is exactly the "ugly" implementation I wanted to avoid, the issue is still active.
If you are using 17b or later, parsim provides an option to 'RunInBackground'. It returns an array of Future objects.
F = parsim(in, 'RunInBackground', 'on')
Please note that is only available for parallel simulations. The Simulink.Simulation.Future object F provides a cancel method which will terminate the simulation. You can use the fetchOutputs methods to fetch the output from the simulation.
F.cancel();

How to update variable in From workspace block during runtime

I have a sample model(shown below) which consist of a from workspace block. It contains a workspace variable variable1(timeseries signal). I am changing the data of variable1 during simulation but model is not updating the current value of variable1. It's update only when I stop and restart the simulation but I want it to update during runtime only. Can anyone help me in handling this problem?
This is not really how Simulink is designed to work, so there's no easy way to do this. Simulink only checks only checks the workspace for values during model initialization at the start of the simulation. The best thing to do is to use set_param, as in:
set_param('untitled/From Workspace',' VariableName','variable1'); % put the correct path to your block
This is not changing anything in how the block is parameterised, but forces Simulink to parameterise the block with the new values of variable1. Because variable1 is a timeseries object, I am not sure how well this will work, but it's worth a try.
For more details, see this discussion on MATLAB Central.

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.

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.