ADR Control Program

Olin College NASA Study

Adiabatic Demagnetization Refrigerator (ADR) Control Program

Olin College Professor Holt and Professor Pratt in collaboration with the XRS team at Goddard Space Flight Center have put together a summer intership for ten Olin College students.

One of the five projects is to modify the control program for an Adiabatic Demagnetization Refrigerator (ADR). It currently uses a basic Proportional Integral Derivatieve (PID) control algorithm. The temperature input occasionally has a data point that is physically impossible, so the new program should take a wider range of data points into account to lessen the effects of the error. There are also other noise issues within the system. The goal of this project is to reduce noise and errors by a factor 10.

Calendar

June

Monday
Tuesday
Wednesday
Thursday
Friday
  1 2
Begin NASA study
3 4
Trip to Goddard
7 8 9
Recieved code & data
10 11
14 15 16
Analyze data
17 18
21 22 23
(Joe is gone)
24
(Joe is gone)
25
Model ADR
28
Get new data & analyze
29
30
   

July

Monday
Tuesday
Wednesday
Thursday
Friday
      1 2
Model system
5 6 7
8

9

12 13 14
Finish & send code
15 16
Refine & send back
19
[Slack time]
20
[Slack time]
21
[Slack time]
22
[Slack time]
23
[Slack time]
26
[Slack time]
27
[Slack time]
28
[Slack time]
29
[Slack time]
30
End of NASA study

 

Timeline in PERT Form

1. Get current ADR control code and some data results from Goddard.
2. Convert log files into Matlab data.
3. Create graphs in Matlab from data results.
4 . Figure out the magnitude of the noise so it can be reduced.
5 . Make further connections with data and what needs to be changed.
6. Understand the physics of the adiabatic demagnetization refrigerator (ADR).
7. Work through the mathematical equations for the ADR.
8 . Understand Proportional Integral Derivative (PID) control and find where it fits in the system.
9. Understand Simulink to model ADR equations.
10. Analyze the new data and figure out exactly where noise is coming from.
11. Model the slow demagnetization step of the ADR using Simulink.
12. Fit the ADR model to the data to find the constants.
13. Figure out good smoothing algorithms.
14. Figure out good algoithms for ignoring outliers.
15. Model the exact system we are using to control the ADR.
16. Become familiar with previous ADR control code.
17. Become familiar with C programming language.
18. Code the best smoothing and algoithms in C.
19. Use code in the model to simulate the new control algorithms.
20. Finish writing the code.
21. Contact Scott to tell him when the code will be there.
22. Email the code to Scott.
23. Get new data from ADR test with new code.
24. Analyze new data.
25. Identify any problems or things that need to be improved upon.
26. Fix Them!
27. Send them back for further tests.
28. Repeat steps 23 to 27 each week until done.

© Olin College NASA Study 2004