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Parameter Tuning and Data Logging

This example shows how to use real-time parameter tuning and data logging with Simulink® Real-Time™. After the example builds the model and downloads the real-time application, slrt_ex_param_tuning, to the target computer, the example executes multiple runs with the gain 'Gain1/Gain' changed (tuned) before each run. The gain sweeps from 0.1 to 0.7 in steps of 0.05.

The example uses the data logging capabilities of Simulink Real-Time to capture signals of interest during each run. The logged signals are uploaded to the development computer and plotted. A 3-D plot of the oscillator output versus time versus gain is displayed.

Open, Build, and Download Model to the Target Computer

Open the model, slrt_ex_param_tuning. The model configuration parameters select the slrealtime.tlc system target file as the code generation target. Building the model creates a real-time application, slrt_ex_param_tuning.mldatx, that runs on the target computer.

model = 'slrt_ex_param_tuning';
open_system(fullfile(matlabroot,'toolbox','slrealtime','examples',model));

Build the model and download the real-time application, slrt_ex_param_tuning.mldatx, to the target computer.

  • Configure for a non-Verbose build.

  • Build and download application.

set_param(model,'RTWVerbose','off');
set_param(model,'StopTime','0.2');
slbuild(model);
tg = slrealtime;
load(tg,model);
### Successful completion of build procedure for: slrt_ex_param_tuning
### Created MLDATX ..\slrt_ex_param_tuning.mldatx

Build Summary

Top model targets built:

Model                 Action                       Rebuild Reason                                    
=====================================================================================================
slrt_ex_param_tuning  Code generated and compiled  Code generation information file does not exist.  

1 of 1 models built (0 models already up to date)
Build duration: 0h 0m 20.514s

Run Model, Sweep 'Gain' Parameter, Plot Logged Data

This code accomplishes several tasks.

Task 1: Create Target Object

Create the MATLAB® variable, tg, that contains the Simulink Real-Time target object. This object lets you communicate with and control the target computer.

  • Create a Simulink Real-Time target object.

  • Set stop time to 0.2s.

Task 2: Run the Model and Plot Results

Run the model, sweeping through and changing the gain (damping parameter) before each run. Plot the results for each run.

  • If no plot figure exist, create the figure.

  • If the plot figure exist, make it the current figure.

Task 3: Loop over damping factor z

  • Set damping factor (Gain1/Gain).

  • Start run of the real-time application.

  • Store output data in outp, y, and t variables.

  • Plot data for current run.

Task 4: Create 3-D Plot (Oscillator Output vs. Time vs. Gain)

  • Loop over damping factor.

  • Create a plot of oscillator output versus time versus gain.

  • Create 3-D plot.

figh = findobj('Name', 'parsweepdemo');
if isempty(figh)
  figh = figure;
  set(figh, 'Name', 'parsweepdemo', 'NumberTitle', 'off');
else
  figure(figh);
end
y = []; flag = 0;
for z = 0.1 : 0.05 : 0.7
  if isempty(find(get(0, 'Children') == figh, 1))
      flag = 1;
      break;
  end
  load(tg,model);
  tg.setparam([model '/Gain1'],'Gain',2 * 1000 * z);
  tg.start('AutoImportFileLog',true, 'ExportToBaseWorkspace', true);
  pause(0.4);
  outp = logsOut.FileLogSignals{1}.Values;
  y    = [y,outp.Data(:,1)];
  t    = outp.Time;
  plot(t,y);
  set(gca, 'XLim', [t(1), t(end)], 'YLim', [-10, 10]);
  title(['parsweepdemo: Damping Gain = ', num2str(z)]);
  xlabel('Time'); ylabel('Output');
  drawnow;
end
if ~flag
  delete(gca);
  surf(t(1 : 200), 0.1 : 0.05 : 0.7, y(1 : 200, :)');
  colormap cool
  shading interp
  h = light;
  set(h, 'Position', [0.0125, 0.6, 10], 'Style', 'local');
  lighting gouraud
  title('parsweepdemo: finished');
  xlabel('Time'); ylabel('Damping Gain'); zlabel('Output');
end

Close Model

When done, close the model.

close_system(model,0);

See Also

Related Topics