SURF arrives at 24th June, and the schedule goes as follows:
Weeks |
Details |
1-2 |
Get familiar with the system and lecturing on feedback control. Calibrate the bias of the DC attracting magnetic force to check if it is possible to eliminate it. Issue 1: The bias turns out to be too large to be compensated by electronics. Possible Solution: Add a small magnet to compensate or replace the magnets with new ones that have smaller bias. |
3-4 |
Calibrate the cross coupling. Method: Transfer function measurement. Equipment: spectrum analyser or digital data acquisition system. Issue 1: How can make a calibration before the system is stable. Possible solution: Use mechanical springs to first create a stable system [what would be the configuration? Issue 2: How to avoid sensing motion in the horizontal direction? Possible solution: use foil to make a narrow silt for the photodiode such that small transverse motion will not couple. |
3-4 |
In parallel with the calibration, work on the analogy circuits for the digital data acquisition (whitening and dewhitening circuits). Items: Bread board and one quad op-amp or 4 individual ones (related capacitors and resistors). First use simple bread board before going to special designed PCBs. |
5-6 |
Work out the control matrix and try to implement digital control. Equipment: Jame's Cymac will possibly not be available then. Backup solution: Digital system in Jan's lab with Labview. |
7-8 |
Stable levitation? If so, work on noise measurement. Issue: This is tricky, as we do not have a way to shake the system in a control way, and only transfer function measurement seems to be possible. Possible solution: Place capacitive actuators underneath the device (feasible?) |
9 |
Summarize the work and work on the final report. |
List of small items needed:
Name |
Quantity |
Purpose |
Availability |
Op-Amp |
8 or 2 quad |
whitening and dewhitening circuit |
40m |
capacitors & resistors |
few |
circuit |
40m |
solderless breadboard |
one |
testing circuit |
there is one spare in 40m |
magnet wires |
1 |
coil wiring |
order this week |
mechanical springs |
10 |
cross coupling |
order this week |
1 and 0.5 inch magnets |
20 |
DC bias |
order this week |
Equipment needed:
Items |
Purpose |
Availability & Status |
One windows computer |
modelling and analogy circuit design |
40m [but the experiment is in west bridge!] |
BNC cables |
input and output |
8 in total (4 for input and 4 for output) from 40m (not yet confirmed)? |
15V/24V power supply |
drive the plant |
from 40m (not yet confirmed) |
Preamplifier SR560 |
tunable gain and filter |
from 40m (not yet confirmed) |
4 channels oscilloscope |
system characterization |
Jan's lab (confirmed) |
Spectrum Analyser |
measure transfer function and take spectrums |
Alternative: Jan's lab gets digital data acquisition system, but needs to be calibrated |
Internal note (to be updated) : SURF_maglev.pdf