Defining Linear Models Interactively (Control Design and Simulation Module)

You use the Continuous Linear Systems functions and the Discrete Linear Systems functions to define continuous and discrete linear system models interactively or programmatically. The LabVIEW Control Design and Simulation Module supports transfer function, zero-pole-gain, and state-space model forms. Complete the following steps to configure a linear model interactively.

1. Place a continuous or discrete Transfer Function, Zero-Pole-Gain, or State-Space function on the simulation diagram.
2. Double-click the function to display the configuration dialog box.
3. Use the Polymorphic instance pull-down menu to specify whether the model is single-input single-output (SISO) or multiple-input multiple-output (MIMO).
4. Select the model parameter from the Parameters listbox. For example, if you are configuring a state-space function, select the State-Space parameter. After you select the parameter, the Parameter Information section shows the configuration options for the model.
5. If the model is MIMO, define the size of the model by using the Inputs and Outputs numeric controls in the Model Dimensions section. The Model Dimensions section is dimmed if you configure a SISO model because SISO models have only one input and one output. If the model is in state-space form, you also define the number of states using the States numeric control.
   
   The following illustration shows a sample configuration dialog box for a MIMO transfer function model.
   
   

   

   
   
   The example in the previous illustration shows a model with two inputs and two outputs. The Inputs and Outputs numeric controls define these dimensions. The Numerator and Denominator vectors define the coefficients of the equation at the current input-output location. The Current Input and Current Output text boxes define the current input-output location. The Input-Output Model matrix also shows this location graphically with a black square.
6. Specify another input-output location by clicking an element in the Input-Output Model matrix. You also can adjust the values of the Current Input and Current Output text boxes. For example, to define the bottom-left equation of the MIMO model in the previous illustration, decrement the value of the Current Input text box by one. You also can click the bottom-left element of the Input-Output Model matrix.
7. Define the model by entering coefficients in the Numerator and Denominator vectors.
8. Click the OK button to save changes and return to the simulation diagram.