"Control! You must learn control!"

-- Yoda

-- Yoda

Due: Wednesday, April 16, 11:00am CDT

Submit: Turn in a Matlab source file and a written report (PDF or plain text) using the`turnin` command on
the Systems Lab
machines.

Work is to be completed individually.

Submit: Turn in a Matlab source file and a written report (PDF or plain text) using the

Work is to be completed individually.

Using Matlab, model a PID controller feedback system for a plant with a gain of 0.05 and a lag of 50ms. Simulate a reference input of the unit step function rising at time t=0. Calculate the integral of the error, e(t), over a one second interval. Your simulation should graph the reference input, r(t), and the plant output, y(t), and output the net error.

Find suitable values for the controller constants (Kp, Ki, Kd) that minimize net error and produce acceptable control.

The purpose of this assignment is not to discover ideal control constants for a completely made-up system. It is to get you to explore the simulation to get a feel for how such a feedback control system can behave. To that end, here are a list of starter questions to get you thinking and playing.

Write up a brief report to accompany your simulation source code that includes thoughtful, well-written responses to these questions, as well as any other relevant observations you take away from the exercise.

- What do each of the control constant terms contribute to the system? What is the effect of too high or too low values of each of Kp, Ki, and Kd?
- How does your system perform with other kinds of reference inputs r(t)? Try a sine wave, a square wave, and a saw tooth.
- How tuned is your control system to this particular model of the plant? Try increasing and decreasing the plant gain and plant delay constants in the model. How do the control constants have to change in order to adequately respond?

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[Revised 2012 Jan 27 10:58 DWB]