NASA Plant Control System

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NASA Plant Control System

• Tim Jou Abby Suelflow
• Advisor Dr. Parten
• Miguel Hinojosa
• 11/29/04

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EDU Information

• The Engineering Development Unit (EDU) is a
  completely controlled unit, that provides varying
  environmental conditions under which plant growth
  can be monitored.
• This project involves faculty and students from
  Plant and Soil Sciences, Biology, Chemistry, ME,
  and EE.
• The EDU unit is located in the Horticultural
  Sciences Building and was constructed in 1993.

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Goal

• To study the effect high levels of carbon dioxide
  might have on plant growth and development.
• To develop a strategy that optimizes conditions
  for growth of green salad onions.

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Objective

• Understand the current system software.
• Make modifications and improvements to the
  current software.

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Outline

• System Overview
• Hardware Testing
• Software Blueprint
• Modifications
• Priorities
• Software Timing
• Debug
• Results
• Conclusions
• Gantt Chart
• Budget

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EDU
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System Overview

• Monitoring and Control Computer Station
• All information collected from the EDU is sent
  thru various Optomux boards
• RS-485 signals are converted to RS-232 for input
  to the computer

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System Overview

• Manual Emergency Electrical Power Disconnect
• Gas supply and storage
• Coolant Chiller System
• Carbon Dioxide (CO2) Mars Atmosphere 95.32

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EDU Main

• Quick view of entire system

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Nutrients

• pH 6.6
• Acid/Base Injections
• Conductivity Control
• Circulation Pump

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Oxygen Scrubbing

• Oxygen Set Point
• CO2/O2 Chambers
• Oxygen Scrubbing

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Pressure/CO2

• Tanks originally set at 27psi
• CO2 Control Level
• Thomas Compressor

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Lighting

• Five groups of three lights
• Set On/Off times
• Displays light level and light bank relative
  humidity

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Condensate

• Standpipe 7 13cm of water
• Drain pump on solenoid off nutrient delivery
  system
• Drain pump and solenoid on oxygen scrubbing
  reservoir

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Relative Humidity/Temperature

• RH level and temperature are regulated by PID
  controllers
• Different night/day settings

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LTL/MTL

• LTL cools CGV, CHX, and equipment bay
• MTL cools light bank HX
• Monitors all temperatures

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Alarms

• Low
• LTL pressure lt 4psi
• MTL pressure lt4 psi
• Nutrient Tray Level high
• CO2 gt 3000 ppm and a light is on
• Light Bank Relative Humidity gt 95

• High
• Cut off power after a 12 second countdown by
  setting the Main
• Breaker Relay (0-14) to zero.
• Cell voltage gt 1.5 volts
• Wetness Sensor gt 2 volts
• EDU to Ambient delta error gt 750
• Hydrocarbons gt 20
• Bay Temperature gt70 C
• Optomux Temperature gt70 C
• Light Bank Down Air Temperature gt70 C

• Medium
• CGV Temperature error gt10 C and Vane in
  Automatic Temperature
• Oxygen Level gt23.5
• Storage Tank delta p lt 1 psi/min and Thomas
  Compressor On
• Bay Temperature gt50 C
• Optomux Temperature gt50 C
• Light Bank Down Air Temperature gt50 C

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EDU History
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Suelflow
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Testing Analog/Digital Boards
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Blue Print
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Tab Labeling
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Possible Modifications
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Modifications

• Prioritize each sub-VI within each tab
• Group sub-VIs by these chosen Priorities
• Add timers to the new groups to control the
  execution of the program
• Unnecessary Features
• Modem/Pager software
• Internet offsite system control

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Prioritize by Category

• High
• Pumps, Pressures Valves
• Medium
• Blowers Sensors
• Low
• Lights, Temperatures Relative Humidities

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Prioritize by Category
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Prioritize by Alarms
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Nutrient Input/Output
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High

• Nutrients
• Base Controller, Conductivity Controller Acid
  Controller
• O2 Scrubbing
• O2 Scrub High
• Pressure/CO2
• Pressure 1 Pressure 2
• Relative Humidity/Temperature
• Vane Controller

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Medium

• Nutrients
• Nutrients NDS Pump
• Pressure/CO2
• Tank Alarm CO2 Controller
• LTL/MTL
• CGV Blower PID

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Low

• Lighting
• Lights
• Pressure/CO
• CO Flow CO Average
• Condensate Recovery
• Drain Rate Condensate Recovery 1 2
• Relative Humidity/Temperature
• Relative Humidity
• LTL/MTL
• Pump 1, Pump2 Pump 3/Light Bank

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Nutrient Loops
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Pressure/CO2 Loops
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High Priority VIs
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Medium Priority VIs
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Low Priority VIs
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Timers
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Testing

• High 100
• Med 1000
• Low 5000
• CPU 100

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More Timers
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Without Timer
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With Timer
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Debug
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Debug
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Results
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Conclusions

• Hardware works, but is quickly deteriorating and
  could be causing problems
• Software
• VIs grouped and prioritized
• Some parts were slowed down, but the program as a
  whole continues to run at 100

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Gantt Chart
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Gantt Chart
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Budget
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Reference

• Deal, Kim, Laboratory Notes, December 2003
• Hinojosa, Miguel
• www.ni.com
• www.ee.ttu.edu/nasa

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Questions

• ?