Steady-State Operating Points From Simulation

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Simulation Snapshot Operating Points Compute Operating Points at Simulation Snapshots

Simulation Snapshot Operating Points

You can compute a steady-state operating point (or equilibrium operating point) from model simulation. The resulting operating point consists of the state values and model input levels at the specified simulation time.

Simulation-based operating point computation requires that you configure your model by specifying:

• Initial conditions that cause your model to converge to equilibrium

• Simulation time at which the model reaches equilibrium

You can use the simulation snapshot operating point to initialize the trim point search.

Note   If your Simulink model has internal states, do not linearize this model at the operating point you compute from a simulation snapshot. Instead, try linearizing the model using a simulation snapshot or at an operating point from optimization-based search.

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Compute Operating Points at Simulation Snapshots

This example shows how to use the Linear Analysis Tool to compute an operating point at specified simulation times (or simulation snapshots).

 Code Alternative

1. Open Simulink model.

   sys = 'magball';
   open_system(sys)

   

2. In the Simulink model window, select Tools > Control Design > Linear Analysis.

   The Linear Analysis Tool for the model opens, with the default operating point being set to the model initial condition.

3. Click Operating Point Snapshot in the Linear Analysis tab.

   

4. Specify [1,10] in the Simulation Snapshot Times field and then press Enter.

   This vector specifies to compute operating points at the t = 1 and t = 10 simulation times.

5. Click Take Snapshots.

   A variable, op_snapshot1, appears in the Linear Analysis Workspace. op_snapshot1 contains the two operating points.

6. Double click op_snapshot1 to see the resulting operating points. Use the Select Operating Point drop-down list to choose the operating point of interest.

   

For example, to evaluate your operating point from a simulation snapshot:

1. Initialize the model at the operating point (see Simulate Simulink Model at Specific Operating Point)

2. Add Scope blocks to show the output signals that should reach steady state during the simulation.

3. Run the simulation to check whether these key signals are at steady state.

 More About

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Steady-State Operating Points (Trimming) From Specifications

Simulate Simulink Model at Specific Operating Point

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