Control SISOs

Use the SISOs tool to set control SISO data. This data can be used to add additional states to the mechanical system being modeled.

Create Controls SISOs

  1. From the Project Browser, select the system to which the Control SISO is to be added.
  2. Right-click on a system in the Project Browser and select Add > Control Entity > Control SISO from the context menu.
    OR
    Right-click on a Control SISO folder in the Project Browser and select Add Control SISO from the context menu.
    OR
    From the Model ribbon, click the SISOs icon.
    The Add Control dialog is displayed.
  3. Specify a label for the control SISO.
    The label can be changed at any time.
  4. Specify a variable name for the control SISO.
    By default, variables names of entities in MotionView follow a certain convention. For example, all control SISO entities have a variable name starting with “siso_”. This is the recommended convention to follow when building models in MotionView since it has many advantages in model editing and model manipulation.
  5. Click OK to close the window or Apply to continue creating entities.
    Once a control SISO entity has been added to the model, the panel for the SISO will automatically be displayed in the panel area.

Edit Control SISOs

Define the Properties of Control SISOs

From the Properties tab, you can edit the control SISO data.

  1. If the Control SISOs panel is not currently displayed, select the desired controSISO by clicking on it in the Project Browser or in the modeling window.
    The Control SISOs panel is automatically displayed.
  2. Enter the coefficient values in the text boxes labeled Numerators and Denominators.
  3. Click Append to add additional numerator and denominator values.
    Clicking Append adds a new numerator/denominator to the bottom of the list.
    Tip:
    • Select the check box next to any of the values and click Insert to add a numerator/denominator directly above the selected entity.
    • To delete a value, select any entity from the list and click Delete.
  4. Define the values for any added numerators or denominators.
  5. Activate the Static hold check box.
    Select this option if the state of the control SISO is not permitted to change during static and quasi-static analysis of the solver. Otherwise, deselect the option.

Define Control SISO Input

From the Input tab, you can set the input to the transfer function of the controller. You can enter initial condition values and enter linear, curve, or expression values.

  1. Click the Input tab.
  2. Click the Initial conditions check box and enter an initial condition value for the control SISO.
  3. Select an option from the Type drop-down menu.
  4. Define the properties associated with your choice.
    If Linear is chosen, enter a value in the text box.
    If Curve is chosen:
    1. Select AKIMA, CUBIC, LINEAR, or QUINTIC as the interpolation method.
    2. Enter a value under Independent variable.
      The independent variable should be specified in Templex syntax.
    3. Resolve the curve by double-clicking the Curve collector and selecting a curve from the Select a Curve dialog.
      Note: To use a curve, you first need to define a curve (using the Curves panel) which represents the behavior of the control SISO.
    If Spline3D is chosen:
    1. Select AKIMA, CUBIC, LINEAR , or QUINTIC under as the method of interpolation.
    2. Specify an expression for Independent variable X and Independent variable Z.
    3. Resolve the 3D spline by double-clicking on the Spline3D collector and selecting a Spline3D entity from the Select a Spline3D dialog.
      Note: To use a Spline3D entity, you first need to define a spline using the Spline3D panel.
    If Expression is chosen, enter an expression.