| Nonlinear Control Design Blockset | |
Nonlinear Control Design Blockset Interface
Problem: Some of the text in dialog boxes is unreadable; the dialog boxes are too small.
Recommendation: Simply resize the dialog box window as you would any other window until it is large enough.
Problem: How can I tell the Nonlinear Control Design Blockset which constraints are most important to meet?
Recommendation: Use the Constraint Editor dialog box to weight constraints relative to each other. For more information on the Constraint Editor dialog box, see Chapter 6.
Problem: Can the appearance of the Nonlinear Control Design Blockset constraint window be altered? Can objects be added/deleted from the constraint window?
Recommendation: The Nonlinear Control Design Blockset constraint window (and dialog boxes) are all MATLAB figures created with Handle Graphics® routines introduced in MATLAB 4.0. You can add objects to the constraint window using primitive functions (like line, surface, and text) as you would add them to any other figure. Objects can be deleted from the constraint window using the delete command, assuming that you have the object's handle. To add objects to the constraint figure using higher level functions (like plot and surf), you must first use: set(0,'ShowHiddenHandles','on'), and obtain the constraint figure window handle. Note that changing a constraint figure's UserData produces numerous error messages.
Problem: I typed clear or clear global at the MATLAB command line and now the Nonlinear Control Design Blockset gives me numerous errors. What happened?
Recommendation: The Nonlinear Control Design Blockset uses a global variable in the base (MATLAB) workspace. Clearing or altering this variable results in numerous errors if you attempt to continue the Nonlinear Control Design Blockset session; you will most likely have to close down all Nonlinear Control Design Blockset windows and begin again.
Problem: How else can the Nonlinear Control Design Blockset interface be affected by MATLAB command line input?
Recommendation: All Nonlinear Control Design Blockset window handles are hidden so that they are protected from interference from extraneous plot commands. However, if you set the hidden handles property to on, then the Nonlinear Control Design Blockset windows are like any other MATLAB figures, hence you must exercise a little extra caution when executing commands that affect graphics objects. For example, typing close all force will close the Nonlinear Control Design Blockset figure windows.
Problem: How can I change the optimization start and stop times?
Recommendation: Use the Simulation Parameters... dialog box on your
Simulink model window to specify the time limits. Notice that the first time an Nonlinear Control Design Blockset constraint figure is created, it automatically uses the system simulation start and stop time. The limits of the time axis can be set independently of the optimization start and stop times; the time axis limits only affect the graphical output.
Problem: Can I use the Nonlinear Control Design Blockset on more than one system simultaneously?
Recommendation: Unfortunately, no. Since the Nonlinear Control Design Blockset uses a global variable in its implementation, you can only design constraints and run optimizations for one system at a time. We expect that future versions of the Nonlinear Control Design Blockset will not have this drawback.
Problem: Does the height of the constraint bounds have any significance?
Recommendation: No. The constraint bound height merely provides a visual cue to help you in manipulating constraints. You must be clicked within the constraint bound in order to stretch the constraint or move it up and down.
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