ECE 421 -- Design Project -- Fall 2001

 

Assigned: Thursday, October 25, 2001
Due: Wednesday, December 19, 2001, 4:00 p.m.

I will not be in the office on December 19, so any technical questions about the project must be asked prior to that date.

The project MUST be turned in to Annaliesa in the ECE Department Office, Room 230, S&T II, on Wednesday, December 19. They may NOT be slid under my office door, put in my mailbox, etc.

Your project will be logged in by Annaliesa when you turn it in to her.  Your project will not be returned once it has been handed in, so if you want copies for yourself, they must be made prior to submitting it.

Projects submitted after Annaliesa leaves at 4:30 will NOT be accepted.  Projects not logged in by Annaliesa will NOT be accepted.

Students are reminded of the statement on individual effort for the project in the first paragraph below.

Introduction:

This design project is to be an individual effort for each of the students.  The George Mason University honor code applies to this project.  Any questions concerning the project should be directed to Dr. Beale.  Suspected violations of the Honor Code will be reported.

In the closed-loop block diagram, the system for this project is seen to consist of the plant transfer function Gp(s), a compensator Gc(s), reference signal R(s), and a disturbance signal D(s).  The plant model represents a linearization of the heading dynamics of the Mariner-class cargo ship.  The reference input signal R(s) is the desired heading angle for the ship, and the output signal C(s) is the actual heading angle.  In this linear system, angles can be expressed in either radians or degrees.  The output of the compensator, U(s), is the commanded rudder angle (control signal) that is used to control the heading of the ship.  The transfer function for the open-loop ship model Gp(s) is given by

The output of the plant is the heading angle, y, and the input to the plant is the actual rudder angle, dr.  In the absence of a disturbance, the actual and commanded rudder angles are equal.

 

Tasks:

  1. Design a compensator Gc(s) such that the following specifications are all satisfied:

  2. when the reference input signal is a step function, and the disturbance signal is 0, the settling time of the actual heading angle must not exceed 200 seconds;

  3. when the reference input signal is a step function, and the disturbance signal is 0, the overshoot in actual heading angle must not exceed 20%;

  4. when the reference input signal is a unit ramp function, and the disturbance signal is 0, the steady-state error must not exceed 1 (no settling time is specified here);

  5. when the reference input signal is 0, and the disturbance signal is a step function, the steady-state value of the output must be 0 (no settling time is specified here);

  6. when the reference input signal is a unit step function, and the disturbance signal is 0, the maximum absolute value of the control signal must not exceed 0.1.

    7.

  7. Perform simulations in MATLAB with your compensator design to verify that all the specifications have been satisfied. Plots should be made that indicate the responses of the various signals are satisfactory.

  8. This part of the project deals with the stability robustness of your compensator design, that is, how much change can there be in the compensator gain without losing closed-loop stability? Determine the range of values of Kc that provides closed-loop stability. Select at least 10 values of gain covering the interval of stability and measure the percent overshoot and settling time in the step response of the system for each value. You may assume that the disturbance signal is 0.

 

Report:

You must provide a typed report that documents your design activity and provides plots that verify that all the specifications are satisfied.  Handwritten reports will not be accepted.  If you wish, you may produce your reports, including plots, in the form of web pages rather than in hardcopy form.  In that case, you must provide me with the URL for your web pages by the time that the project report is due.

Your report must describe your design approach and explain how the approach is able to satisfy the design specifications.  Your report must reference the plots that are included in it.  The plots must clearly demonstrate that the specifications are satisfied, and the plots must be clearly labeled with axis labels and titles. 

Include in the report plots and a discussion of your analysis of the robustness of your control system.

Click the icon to return to the Dr. Beale's home page

Lastest revision on Wednesday, June 7, 2006 9:14 PM