Transcript Objectives Overview

Objectives Overview
• Objective: Create an Earth field unit to
test electrochemical sensors
• Deliverables:
– Field-ready unit
– Test data verifying requirements
– Operational manual for use
– Document proposing design solutions to
make the instrument more Mars-ready
• Mars-applicable solutions do NOT have to be
implemented on field unit
Requirements Overview
• Changes to PDD requirements:
– Requirement 4.24 removed: MiDAs must no longer provide
its own power
– Will still be able to accept power from various sources
– Power supply options will be included in design document
• Project Focus Change:
– Complete autonomy no longer crucial component
• Increased reliance on experimenter to open valves and deliver
inoculation sample
• Change at request of customer – tradeoff of autonomy versus
reliability in field instrument
• Autonomy deemed out of the scope of this project
• Autonomy options will be included in design document
– Autonomous data collection and storage, heating, cooling,
and mixing still part of design
System Architecture
Chambers
Reaction Chambers
Reagent Water Chamber
Autoclave Chambers and Cap
Subsystem Breakdown
Environmental Chamber
Chassis
Pump and Mount
Electrical Block Diagram
12VAC/
Power Source
12V
12VDC
Power
Conditioning/
Protection
AHC2: Autoclave heater/cooler 2
AHC1: Autoclave heater/cooler 1
An.In: Analog input
An.out: Analog output
AP: Ambient Pressure Sensor
AT: Ambient Temperature Sensor
RT
AP2: Autoclave Pressure Sensor2
AT2: Autoclave Temperature Sensor2
CP: Control Chamber Pressure Sensor
CT: Control Chamber Temperature Sensor
12V
Power Distribution/
Switching
Communication (USB)
AT
Dig.Out
AP1
Data Acquisition/
Control
An.out
AP2
AHC1 Temp control/
Power Cut off
V2
V1
AHC2
Autoclave 1
Autoclave 2
SG1
SG2
L1
Water Pump
AP
An.In
AP2
AT1
Reagent Water
Chamber
Control Switch
CPU
ET
L2
TP
Control Chamber
Test Chamber
TT
CP
Dig.Out: Digital Output
Temp
Control/
Power cut
off
CT
ET: Environmental Temperature Sensor
IHC: Incubator Heater/Cooler
L1: Light 1
L2:light 2
Speed control
M1
Electrochemical
Sensors(18)
M1: Mixer 1
M2: Mixer 2
RT: Reagent Water Temperature Sensor
SG1: Soil Transportation Gate 1
SG2: Soil Transportation Gate 2
TT: Test Chamber Temperature Sensor
TP: Test Chamber Pressure Sensor
V1: Water Valve 1
V2: Water Valve 2
Temp control
IHC
Test Chamber Environment
M2
Speed control
Experiment Timeline
min
Description
t=0
begin autoclave cycle
again
Measurement
Test
yes/no
Is t = 317?
t = 318
begin autoclave cycle
again
Is t = 635?
t = 636
begin autoclave cycle
again
Is t = 953?
t = 954
Autoclaving complete
visual
Heater is off Cooler is
off
Are heater and cooler off?
Are valves open?
begin soil
transportation
t = 955
t = 956
finish soil
transportation
temperature
initialize sensors
pressure
inoculate
Electro-chemical
begin mixing
temperature
temperature control
pressure
Electro-chemical
Is pump done?
Is data being
recorded/electro-chemical
zeroed?
Is test chamber inoculated?
Is temperature <= 6°C?
Is temperature >=35°C?
Control
heat
cool
yes
off
off
increment time, move to next
step
no
-----
-----
continue autoclave cycle
yes
off
off
increment time, move to next
step
no
-----
-----
continue autoclave cycle
yes
off
off
increment time, move to next
step
no
-----
-----
continue autoclave cycle
yes
open auto clave ejection valve and
water valve
perform next test
no
Stop, check for failure
stop
yes
pump 25mL water through
autoclave
increment time, move to next
step
no
Stop, check for failure
stop
yes
close valves, begin taking
measurements, zero
electrochemical sensors
perform next test
no
--------------
increment time, repeat
yes
inoculate
increment time, move to next
step
no
Stop, check for failure
stop
yes
turn on mixers
perform next test
no
stop, check experiment for failure
stop
yes
--------------
on
off
perform next test
no
--------------
off
off
perform next test
yes
--------------
off
on
increment time, repeat until t =
21116
no
--------------
off
off
increment time, repeat until t =
21116
Thermal Analysis
Q  mcp Tsteel  mcp Twater  mcp Tsoil

Q
Tinside  Tsurroundin gs
Rtotal

Q

Q
 t

theat  2.8hrs
tcool  1.3hrs
Mass Analysis
•
•
•
•
•
•
•
•
•
Peristaltic Pump & Motor = 106g
Shared Environment = 646g
Reaction Chambers =173g
Water Chamber = 132g
Autoclaves = 263g
Insulation = 20.5g
Chassis = 1.150 kg
Sensors = 10.0g
Valves = 454g
• Total = 2.95Kg
Power Summary
Power Summary (Experiment)
25
Thermal
15
Structures
Electronics
10
Total
5
96
0
10
80
12
00
13
20
14
40
15
60
16
80
18
00
19
20
84
0
72
0
60
0
48
0
36
0
24
0
0
0
12
0
Power Consumption (W)
20
Operation Time (min)
Autoclave Power Summary
Power Summary (Sterilization Phase)
25
Autoclave Heater/Cooler 1
Autoclave Heater/Cooler 2
DAq
Temp/Pressure Sensors
Total Power
20
15
10
5
Operation Time (min)
12
00
10
80
96
0
84
0
72
0
60
0
48
0
36
0
24
0
12
0
0
0
Power Consumption (W)
30