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Assignment 14

Web Assignment 14
Proportional-Integral Experiment
1. You got here. Good going!
2. You are to use the values of the tuning parameters that you found in the last Assignment to run today's experiment.
3. Click on "Proportional-Integral Feedback Control Experiments"
4. Fill in your name, location & email name and then select a "length of experiment" and values of the paramenters.
5. View the results and analyse the response.
6. Repeat for different values of the two tuning paramters (say, 20-50% larger and 20-50% smaller for each). Analyse the results graph to observe the impact of the two tuning parameters.
In the instructions #4 through #6, it is somewhat vague about what values to use as Kc and the integral-time (Tau-i).

Here are some suggestions:

Pick a value for the integral-time (Tau-i); 3.33*to would be a good start.

Find the largest value that you think reasonable for Kc (This should be close to Kcu -- let's say 25 %/out-unit)

Then find the smallest that you think reasonable for Kc (This should be close to Kc-cd -- let's say 1 %/out-unit)

Pick about 5 values of Kc in this range (or slightly beyond the range is OK, too).

(let's say-- 40, 25, 10, 4, 1, 0.5, for examples)

Run an experiment with all other parameters the same for all experiments and vary Kc over the values in this list.

Then choose another value for the integral-time (Tau-i); say, 4 times as large as before & repeat the various experiments. Then choose another value of the integral-time (Tau-i); say 1/4 of the first integral-time (Tau-i) and repeat the various experiments.

Look at all the graphs, look at offset, overshoot, decay ratio, frequency, for all of them. Make a table of all these results, in order according to Kc

Then describe the table, include it in your assignment report and discuss what you observe.

7. Conduct an experiment to look at reset windup. Start off with a small set point. Then change the set point to a value that is near the upper operating limit of the system. View the results and analyse the response.
8. Send an e-mail (report) within the next few days. (Click on "report" to get instructions.)
**** CONTINUOUS IMPROVEMENT ***

For suggestions and feedback,

contact Jim Henry - Lab-Master Send E-Mail to Jim Henry
14 November 1997, Last revised 15 April 1998

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