Purpose
Running the GUI
Using the GUI

Purpose

The purpose of this Graphical User Interface (GUI) is to allow the user to view an animation of the Pitch Controller with the step response plot. This allows the user to see the correlation between the plot and the systems physical response.

The animation and GUI are based on the Pitch Controller:State-Space example. For more information on the system model please refer to the Pitch Controller: Modeling page.

Running the GUI

pitchgui.m - contains the interface and controls.
pitchfun.m - contains the GUI callback function.

Once these files are copied into your MATLAB directory, simply enter the following command:

pitchGUI

Using the GUI

The first group of controls contains the RUN and RESET buttons. These controls perform most of the work in the GUI.

RUN - This button performs the simulation, plots the response in the upper-right axes and runs the animation in the lower-right axes.

RESET - This control clears the upper-right step response plot and sets the pitch angle to zero in the lower-right plot. If a plot is not cleared the next run will be plotted on the same plot. This is useful if you want to see graphically the difference changing some values makes.

An example of the animation and response plot are shown below. The red line in the animation represents the plane's elevator.

The next group of controls allows you to set the weighting factor of the Q matrix for the LQR design method utilized in the animation. For more information on LQR and weighting factors for this problem click here.

PITCH ANGLE FACTOR - This editable text field weight's the plane's pitch angle in the LQR controller. Increasing the weighting factor improves the plane's response, making it reach it's commanded position faster.

Feel free to change the weighing factors to see what happens!

This group of controls allow you to change the step input command.

STEP-SLIDER - The slider allows you to change the step input command. You can click on the arrows to move the slider, grab the the slider bar and move it, or click on the slider to change the step input. The current value of the step input is displayed in the upper portion of the box.

This group of controls contains checkboxes that allow the user to change various features of the GUI.

MANUAL ADVANCE - If this control is checked the user is able to advance the animation and plot one frame at a time. The frames are advanced by pressing any key on the keyboard. This function is useful is the animation moves to fast for the user and will allow the user to see everything that is going on.

PLOT SEPARATELY - By checking this box the step response plot is graphed in its entirety before the animation is run.

REFERENCE INPUT - This box is automatically checked when the GUI is run. By un-checking it the user removes the reference input term, Nbar, from the simulation. The reference input is used to correct steady-state errors common to full-state feedback systems.

REMEMBER, this GUI is intended to be an interactive learning tool that will allow the user to get a feeling for how some basic control techniques and ideas are represented in the real world. Therefore, the user is encouraged to PLAY around with this tool to enhance their understanding of controls.

Pitch Controller Examples

Modeling | PID | Root Locus | Frequency Response | State Space | Digital Control | Simulink

Animations

Bus Suspension | Inverted Pendulum | Pitch Controller | Ball & Beam

Tutorials

MATLAB Basics | MATLAB Modeling | PID | Root Locus | Frequency Response | State Space | Digital Control | Simulink Basics | Simulink Modeling | Examples | Animations