Simulink® Control Design™

Selecting Closed-Loop Responses to Design

This section continues the magball example from Picking Blocks to Tune. At this stage in the example a compensator design task has been created, and tunable blocks have been selected.

In this step of the compensator design task, you will select the closed loops whose responses you want to design in your model. A closed-loop system is defined by an input point, such as a reference or disturbance signal, and an output point, such as a measured output or actuator signal. The Simulink Compensator Design Task uses linearization points on the signal lines of the model to determine the closed-loop systems. For more information on linearization points, see Configuring Inputs and Outputs for the Linearized Model.

In this example you will design the response of the closed-loop system from the reference signal to the output of the plant model. To set up linearization points to define this closed-loop system, perform the following steps:

1. On the magball model diagram, position the mouse on the Reference signal between the Desired Height block and the Sum block. Right-click and select Linearization Points > Input Point from the menu to add an input point.

2. Position the mouse on the signal line at the output of the Magnetic Ball Plant block. Right-click and select Linearization Points > Output Point from the menu to add an output point.

The magball model should now appear as follows:

Within the Control and Estimation Tools Manager, click the Closed-Loop Signals tab of the Simulink Compensator Design Task node to view the input and output points in the model.

Within this pane you can view the input and output signals in the model and use the Active column to select the ones you want to use to define closed-loop systems for compensator design.

Picking Blocks to Tune

Selecting an Operating Point