04 Jun Explain the reason for performing the experiment and give a concise summary of the theory involved, including any mathematical detail relevant to later discussion in the report. ?Conclu
Abstract
A brief description of the experiment. The abstract should not exceed four or five sentences.
Introduction
In your own words, explain the reason for performing the experiment and give a concise summary of the theory involved, including any mathematical detail relevant to later discussion in the report.
Conclusions
This section should reflect your understanding of the experiment. Important points to include are a brief discussion of your final results, an interpretation of the actual experimental results as they apply to the objectives of the experiment set out in the introduction should be given
ANSWER ALL THE QUESTIONS
EET220
Industrial Application
Instructor: enter instructor name
Lab 6
Proportional and Proportional – Integral Control System
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Honor Pledge:
I pledge to support the Honor System of ECPI. I will refrain from any form of academic dishonesty or deception, such as cheating or plagiarism. I am aware that as a member of the academic community, it is my responsibility to turn in all suspected violators of the honor code. I understand that any failure on my part to support the Honor System will be turned over to a Judicial Review Board for determination. I will report to the Judicial Review Board hearing if summoned.
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Student Name Date: 1/1/2018
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Contents Abstract 3 Introduction 3 Part 1: Methods and Procedures 4 Part 2: Methods and Procedures 12 Conclusion 14 References 15
Abstract
|
(This instruction box is to be deleted before submission of Lab report) What is an Abstract? Write the Abstract, Introduction and Conclusion last! This should include a brief description of all parts of the lab. The abstract should be complete in itself. It should summarize the entire lab; what you did, why you did it, the results and your conclusion. Think of it as a summary to include all work done. It has to be succinct but yet detailed enough for a person to know what this report deals with in its entirety. |
I ntroduction
|
(This instruction box is to be deleted before submission of Lab report) What is an Introduction? Write the Abstract, Introduction and Conclusion last! In your own words, explain the reason for performing the experiment and give a concise summary of the theory involved, including any mathematical detail relevant to later discussion in the report. State the objectives of the lab as well as the overall background of the relevant topic. |
Part 1: Methods and Procedures
I. Objectives:
After completing this lab experiment you should be able to tune and understand the,
· Behavior of Proportional (P) system.
· Behavior of Proportional – Integral (PI) system.
II. Procedures:
1. Download the LabVIEW file EET220_Lab_6_LabVIEW_file_Online.vi file from canvas.
2. On the front panel, there should be two tabs Introduction and Operations as seen in Figure 1 below. The introduction tab gives an overview of the simulator with a review of Piping and Instrumentation Diagrams (P&ID). The operation tab has the tank simulator.
Tabs
Figure 1: Introduction tab of VI
3. Select the operation tab in the LabVIEW VI it should look like Figure 2 below.
Setpoint Slider
PID Gains
Figure 2: Operation Tab of VI
4. Review the Figure 2 above to become familiar with your Setpoint and PID gains before getting started.
5. Run the LabVIEW VI, by clicking on the white Run button or using shortcut Ctrl + R.
6. Leave the VI in the RUN mode. Now tune the setpoint slider and observe the red plot which is the set point changes from 100 to 0.
7. On the graph, the blue plot is the current location of the process variable which is the feedback signal coming from the tank level sensor.
8. Now tune the setpoint Slider. Since the PID gains are set to zero, the controller output (Green Plot) should stay at 0, so the tank level will not change.
9. Going forward, we will tune the PID gains of this control system such that the blue plot (current level of the tank from the tank level sensor) should follow the red plot (set point) as quickly and as closely as possible.
Part I: Proportional Control
10. Now, set the proportional gain (Kc) to 5 and integral time to 0.
11. Fill the following table by tuning the Setpoint Slider.
|
Setpoint Slider |
Set point value |
Tank Level Sensor output |
Steady State Error (SSE) |
Oscillations (yes/no/small/large) |
|
Setpoint @ 20 |
20 |
15.88 |
4.12 |
small |
|
Setpoint @ 100 |
100 |
86.38 |
13.62 |
small |
Table 3: Output and error reading when Kc = 5
12. Does the tank level output (blue plot) follow the set point (red plot) closely? Explain the reason below.
The output continually tries to match the setpoint, persistently adjusting itself for alignment.
13. Put back the Setpoint slider to 100. Now, set the proportional gain (Kc) to 10 and integral time to 0. Write your observations below?
Upon reaching 92.8, the output exhibits significantly more stability, although it doesn't perfectly align with the setpoint.
14. Fill the following table by tuning the setpoint slider.
|
Setpoint Slider |
Setpoint Output |
Tank Level Sensor Output |
Steady State Error (SSE) |
Oscillations (yes/no/small/large) |
|
Setpoint @ 100 |
100 |
92.82 |
7.18 |
small |
|
Setpoint @ 20 |
20 |
17.85 |
2.15 |
small |
Table 4: Output and error reading when Kc = 10
15. Compare the results from Table and with Table 4 with the Setpoint at 100, what happened to the steady state error (SSE) with the Setpoint set at 100, there is a noticeable change in the steady state error (SSE). The SSE decreased from 13.62 in Table 3 to 7.18 in Table 4.
16. Now, change the value of Kc to 15 and integral time to 0.
17. Now, now adjust the Setpoint slider to 50. Now the Tank level (blue plot) should begin to move towards the setpoint (red plot). The system begins to oscillate sometimes for a long time before reaching to the steady state. The steady state error (SSE) when compared to Kc = 10 is decreased.
18. Now change the gain Kc to 20. Write your observations below.
When the gain Kc is adjusted to 20, the system starts experiencing significant oscillations, preventing it from achieving a steady state.
19. So, in a proportional control system, as the proportional gain (Kc) increases, the steady state error decreases and tendency for oscillations are increased.
20. Increase the Kc value in steps of 1 and move the Setpoint slider, observe the response of the system and from your testing choose proper Kc value required, so that the oscillations are minimum. The chosen kc value is ___________13__.
Part 2: Methods and Procedures
Part II: Proportional – Integral Control
21. Since proportional control alone cannot eliminate the steady state error, we will incorporate integral action into the control loop. When we add integral mode to the system, the controller continues to make the adjustments until the Tank level feedback voltages match with the setpoint voltage meaning until the SSE is zero.
22. Leave the Setpoint slider around 50% and adjust the Integral time to Ti = 0.01.
23. What happened to the system?
The system developed a large oscillation.
24. Increase the value of Integral time (Ti) by considering all the following guidelines
a. After setting Ti, move the setpoint slider from one value to the other and wait. The tank level should move gradually without developing large oscillations (It is recommended that Ti should be increased by 0.01 with each test).
b. When you see the oscillations are large, increase the Ti.
c. Also make sure the blue signal will not overshoot the red one.
d. Reach to the setpoint as quickly as possible without large oscillations and overshoot.
25. As you increase the Ti, what happened to the following?
a. Oscillations _________getting smaller______________________________
b. Time to reach towards the set point _____120_______________
c. Steady state error ____________.20______________________
d. Amount of overshoot ___________50.20_____________________
26. Based on the above tuning process the Ti value you end up with is _____.08_____.
Conclusion
|
(This instruction box is to be deleted before submission of Lab report) What is a Conclusion? Write the Abstract, Introduction and Conclusion last! This section should reflect your understanding of the experiment conducted. Important points to include are a brief discussion of your results, an interpretation of the actual experimental results as they apply to the objectives of the experiment set out in the introduction should be given. Also, discuss any problems encountered and how they were resolved. |
(Students need to write this).
References
Bartelt, T. L. (2011). Industrial Automated Systems: Instrumentation and Motion Control. Cengage Limited. https://ecpi.vitalsource.com/books/9781305474277
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