1. Evolution of the gas system control for flight
WINCAN
Macro
WINCAN
WINCAN
Diagnostic
WINCAN
Basic
stop
not ok ok
WINCAN
Monitor
Code and Manual available at:
F.Spada – AMS TIM April ‘06

2. ISS <-> ground data communication – software location
WINCAN Macro
state definitions
JMDC
HRDL
WINCAN Monitor
check list
ISS
GROUND
WINCAN Macro
State definitions, mixing)
log files PC
WINCAN Diagnostic
WINCAN Basic
user interfaces
WINCAN Monitor display
TRD Status display
F.Spada – AMS TIM April ‘06

3. Security checks
Security conditions to be verified before operating on the system
On valves:
Forbidden to open a valve if the last temperature readout is too old or if temperature is under a fixed threshold
Forbidden to open a valve if a heater is on (not enough power)
Before opening a valve on the tank - D vessel line, disable the upstream one (avoid two valves open at a time)
On heaters
No heater on if a Marotta valve is open (not enough power)
Keep average dissipation (duty cycle) under a fixed threshold
These conditions are automatically taken into account in what follows
F.Spada – AMS TIM April ‘06

4. Defined states of the gas system/1
To minimize the communication with space:
define states of the system – the definition resides on the JMDC
from ground only send command “bring system in status x”
Examples of defined states:
state “Ground”
Disable all Marotta
Heaters off
box S
Disable all Marotta
Close V8
Pumps off
HV off
Heaters off
box C
manifold
Close all VA, VB, VC, VD
F.Spada – AMS TIM April ‘06

5. Defined states of the gas system/2
state “Empty”
bring to “Ground” state
box S
bring to “Ground” state
box C
verify temperature
open V4
box S ok
not ok
open V18
box C
heaters on
bring to “Ground” state
box S
bring to “Ground” state
box C
verify pressure
in D
not ok ok
F.Spada – AMS TIM April ‘06
stop

6. Defined states of the gas system/3
state “Ready”
bring to “Ground” state
box S
bring to “Ground” state
box C
manifold
bring to “Ground” state
verify temperature
open V8
box C ok
open all VA, VB, VC, VD
manifold
not ok
heaters on
F.Spada – AMS TIM April ‘06

7. Defined states of the gas system/4
state “Run”
bring to “Ready” state
box S
bring to “Ready” state
box C
manifold
bring to “Ready” state
verify P2 ok
not ok
stop
pumps on
box C
verify temperature
HV on
box C ok
not ok
F.Spada – AMS TIM April ‘06
heaters on

8. Diagnostic procedures/1
Example of a procedure to determine the status of electromechanical components: check of the Marotta valves in the box S after a dysfunctional behaviour of the pressure in the D vessel.
F.Spada – AMS TIM April ‘06

9. Diagnostic procedures/2
open V1A
open V2A
open V3A
V1A = ok V1B = ?
V10A = ? V10B = ?
V2A = ok V2B = ?
V3A = ok V3B = ?
V20A = ? V20B = ?
measure P2A ok
stop
not ok
measure P2B ok
stop
P2A = ko
not ok
open V10A
open V2A
open V3A
measure P2
V1A = ko V1B = ?
V10A = ok V10B = ?
V2A = ok V2B = ?
V3A = ok V3B = ?
V20A = ? V20B = ? ok
stop
not ok
F.Spada – AMS TIM April ‘06

10. Diagnostic procedures/3
open V20A
open V20B
open V2B
open V3B
V1A or V10A = ok V1B = ?
V2A or V3A = ko V10B = ?
V2B = ok
V3B = ok
V20A = ok V20B = ok
measure P2 ok
stop
not ok
open V1B
open V2B
open V3B
(V1A & V10A) or V20A or V20B = ko
V1B = ok
V10B = ?
V2A = ? V2B = ok
V3A = ? V3B = ok
measure P2 ok
stop
not ok
F.Spada – AMS TIM April ‘06

11. Diagnostic procedures/4
open V10B
open V2B
open V3B
measure P2
(V1A & V10A) or V20A or V20B = ko
V1B = ko
V10B = ok
V2A = ? V2B = ok
V3A = ? V3B = ok ok
stop
not ok
open V20A
open V20B
open V2A
open V3A
V1A & V10A = ko
V20A & V20B = ok
V1B or V10B = ok
V2A = ok
V2B or V3B = ko
V3A = ok
measure P2 ok
stop
not ok
stop
P2a, P2b ko???
F.Spada – AMS TIM April ‘06

12. Summary WINCAN split in four branches Basic Monitor Macro Diagnostic
Security conditions included
Defined states of the system
To do:
Continue with safety study
More diagnostic procedures …
F.Spada – AMS TIM April ‘06

13. State “Ground” F.Spada – AMS TIM April ‘06 Box S Manifold disable V1a
disable V1b
disable V10b
disable V2b
disable V3b
disable V20b
disable V4b
close VimA
close VimB
close VimC
close VimD
i = 1, …,5 (6)
m = 1, …,8
heaters off
Box C
disable V6a
disable V18a
disable V6b
disable V18b
close V8a
close V8b
heaters off
CP1 off
CP2 off
F.Spada – AMS TIM April ‘06
HV off