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Diffuser Control Logic. Marco Apollonio, Univ. of Oxford. 3 main movements & accurate positioning Carousel (revolving) Discs (+/- 15 deg) Unload disc holder / load catcher (+15, +15) Unload catcher / load disc holder (-15, -15) Catcher (linear motion through a threaded cylinder) - PowerPoint PPT Presentation
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m. apollonio CM18, RAL - UK - 13/06/2007 1
Diffuser Control LogicMarco Apollonio, Univ. of Oxford
m. apollonio CM18, RAL - UK - 13/06/2007 2
• 3 main movements & accurate positioning
– Carousel (revolving)– Discs (+/- 15 deg)
• Unload disc holder / load catcher (+15, +15)• Unload catcher / load disc holder (-15, -15)
– Catcher (linear motion through a threaded cylinder)
• Sequence of operations & Control
0+15
-15
m. apollonio CM18, RAL - UK - 13/06/2007 3
movements & positioning
m. apollonio CM18, RAL - UK - 13/06/2007 4
5 optical sensors to check disc position (4) +disc presence (1)
MICE axis
encoder
m. apollonio CM18, RAL - UK - 13/06/2007 5
4 bit ~Gray code
When this bit is 1 we sense the disc
m. apollonio CM18, RAL - UK - 13/06/2007 6
2 -switches(check if disc at bottom of TH) 1 optical sensor(check if disc at top of TH)
S1
S2
OS
catc
her
Pb
disc
+ fr
ame
m. apollonio CM18, RAL - UK - 13/06/2007 7
OS: carousel and disc
OS
: disc holder
encoder
m. apollonio CM18, RAL - UK - 13/06/2007 8
m. apollonio CM18, RAL - UK - 13/06/2007 9
logic & control
in progress!
m. apollonio CM18, RAL - UK - 13/06/2007 10
NAMING CONVENTIONS
• Motor A : CAROUSEL (+A, clockwise; -A, counterclockwise)
• “ B : DISC HOLDER(s) (+/-B=+/-15deg)
• “ C : CATCHER (+C= in, -C=out)
m. apollonio CM18, RAL - UK - 13/06/2007 11
Start: go to Nf
(S1&&S2) off?
OS on?
OS on? Which discis in? Nd
Move C to position Nd
Nd = 0
Extract disc
Move catcher to bottom
Move C to position Nf
Insert disc
Go to dummy station
STOP
Move Catcher to top
STOP !!!ERROR
align disc holder:motor ACW (-15 deg abs)
align disc holder:motor CW (+15 deg abs)
Move catcher to bottom
Go to dummy station
Command: set disc-f for run mode
NB: need to know WHICH disc is in !
Diffuser Control Flow Chart:main cycle
m. apollonio CM18, RAL - UK - 13/06/2007 12
Diffuser Control Flow Chart:
check discs insertedat the end of this cycle I should have a 5-element vector like (1,1,1,0,1) telling which station is empty. If the number
of empty stations (Ne) is greater than 1 an error is produced which stops the
system
Sense disc
START
GO TO position Ns
Record station (Ns: 0,1)If 0 Ne=Ne+1, Nd=Ns
If 1 NT=NT+1
Ns=1NT=0, Ne=0
Ns>=6
Ns=Ns+1
Go to dummy station
Ne<=1?
STOP !!!ERROR
m. apollonio CM18, RAL - UK - 13/06/2007 13
Diffuser Control Flow Chart:
move C to position NdRotate CAROUSEL C.W.
(till OS fires Nd)Turn ON motor (+A)
STOP
START
OS firing on mark Nd?
1. STOP motor (A) 2. Push BR-PIN3. Start timer
1. release BR-PIN
t>3 s?
OS reads Nd?
STOP !!!ERROR
m. apollonio CM18, RAL - UK - 13/06/2007 14
Diffuser Control Flow Chart:Extract Disc
STOP
START
t > 5 s?
1. Pull linear stage OUT = turn motor on (-C)2. Activate TIMER (check extraction time t)
S1 && S2) off?
STOP !!!ERROR OS on?
Turn C-motor offNB motor be stiff/stable
Unlock catcher: turn motor ACW -15deg
Encoder reads -30?
Update DISC position in memory CTRL program
Y
N
Align disc holder(s)turn motor CW +15deg abs
m. apollonio CM18, RAL - UK - 13/06/2007 15
Diffuser Control Flow Chart:Insert Disc
STOP
START
Encoder +30?
Unlock circular plate:Turn motor CW +15 deg
STOP !!!ERROR
Turn B-motor off (B)Turn on (+C):
• Push linear stage• Activate timer
t > 5 s?
OS off?
Register DISC POSITION in memory for the CTRL PROGRAM
S1 || S2) on?
Turn C-motor off
Y
N
m. apollonio CM18, RAL - UK - 13/06/2007 16
Conclusion
• control for diffuser based on optical sensors and mechanical -switches
• design nearly finished
• logic in progress
m. apollonio CM18, RAL - UK - 13/06/2007 17