gas safety system for oil drilling sites using wireless sensor network
TRANSCRIPT
Gas Safety System for Oil Drilling Sites using Wireless Sensor
Network
Proposed by:Farouq Muhammad Aliyu (g201303650)Mohammed Al-shabouti (g201305830)
Submitted to :Dr. Abdulaziz Barnawi 1
Outline• Statement of Problem
• Aim
• Literature Review
• Introduction
• MODBUS
• Zigbee
• GPS
• Proposed GAS Safety System
• System Requirements
• Results & discussion
• Experiences
• References2
Statement of Problem
• 64% of accidents that happen in the oil fields are due to
Combustibles and/or Toxic gases [1].
• Combustibles and/or Toxic gases detectors are expensive and
difficult to implement.
• Present systems provide a central warning point.
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Aim
The aim of the project is to development of safety system that is
capable of remotely monitoring presence of Hydrogen Sulfide
(H2S) gas in oil drilling site with the help of standard industrial
sensors and wireless sensor networks.
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MODBUS• Transmission in two modes:
Remote terminal Unit(RTU) and ASCII.
• Modbus RTU uses RS-485 or RS-232. Modbus TCP uses Ethernet.
• The types of registers referenced in Modbus devices include the following:• Coil (Discrete Output)• Discrete Input• Input Register• Holding Register
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MODBUS Cont’d• Advantages:• It offers data transmission speeds of 35 Mbit/s up to 10 m and
100 kbit/s at 1200 m• Can connect up to 32 masters, but communicates with one at a
time.• It is highly resistant to noise. • It is cheap (free).
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Zigbee• Developed by Zigbee Alliance based on IEEE 802.15.4
MAC/PHY for low-power consumption• Zigbee stack is scalable and can be co-existed with other
technology use ISM band • Data rate is 250Kbps and ISM band is 2.4 GHz
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Zigbee (Highly Reliable Operation)
• Data Coding • QPSK modulation with conversion of 4-bit data symbols to 32-bit
chip sequences so probability that a message will get through to its destination intact is high.
• Listen before send (CSMA-CA)• Next hop acknowledgements • Scan best channel• Route repair
• So it is suitable for gas safety system
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GPS• Satellite based system provide receiver
with location and time information.[5]• 24 satellites cover the earth• Four Satellites must be line of sight to
get accurate data.• Each position on earth has unique• Longitude • Latitude
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System Requirements
• Should be cheap to encourage customers to buy it. • Should be distributed, flexible and independent
of any other system. • Response time of the system should not exceed
120s [7]• Node lifetime should be greater than one shift (8
hours)
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Hardware • Industrial Sensor & controller • Function:
Sense the gas and send reading to the controller
• Arduino platform + Xbee + Modbus circuit• Function:
Read sensing data from industrial controller. Sends alarm and receives GPS data to and from end nodes.
• Arduino platform + Xbee• Function:
Relay node14
Hardware cont.• Arduino platform + Xbee + GPS (EM406A)• Function:
• Receives alarm and alerts worker• Sends GPS location if required• Aggregates GPS data• Sleep most of the time
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Aggregation Method• GPS can makes error with 10m• End node will not send new GPS data unless
new GPS location differs from old one by more than 10m• Distance between (lat1,long1) (lat2,long2) is computed as[6]
• Processing power consumption!!• Instead we used:
(abs(oldLat-newLat)>0.0001 || abs(oldLong-newLong)>0.0001) 18
Response Time• Response time : Time from sending alarm till, start receiving
GPS position.
• Figure show the average response time.
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Conclusion• The system has a latency of 5 seconds (which is very
acceptable compared to the 120 second bench mark in [4])• Atmega alone (without the arduino board) consumes
extremely less energy.• Tarduino = Ahr/I = 6 days Tatmega = Ahr/I = 10 months
• Therefore WSN can be used for gas safety system.
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DLINE problem• Shield
An extenction for the arduino for
• UART switch to communicate via USB• DLINE switch to communicate with shield
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Programming…• Bluetooth com ports conflict with both xbee and arduino
programming applications (IDEs).• Solution: Always turn off bluetooth/wifi
• Rejoining• If NJ < 0xFF, joining will be enabled only for a numberof seconds,
based on the NJ parameter• Sleep pin
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References
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[5] http://en.wikipedia.org/wiki/Global_Positioning_System[6] http://www.movable-type.co.uk/scripts/latlong.html[7] Standard EN. 50194.2000, Electrical apparatus for the detection of combustible gases in domestic premises. Test methods and performance requirements, September 15, 2000