MENG584- Final Project
Kian Jazayeri
105234
Fazel Farazandeh
105262
Introduction

The aim of this study is to analyze the effect of applying wireless
sensor network technology in industrial platforms and the
corresponding technical difficulties and design goals.

In following section, the specifications of two IWSN standards
(Zigbee and WirelessHart) are compared.

Finally a real case of applying IWSN in Oil and Gas industries
which is considered as a continuous manufacturing platform will be
discussed.

A wireless sensor network (WSN) consists of spatially
distributed autonomous sensors to monitor physical or environmental
conditions, such as temperature, sound, vibration, pressure, motion or
pollutants and to cooperatively pass their data through the network to a
main location.

The WSN is built of "nodes" – from a few to several hundreds or
even thousands, where each node is connected to one (or sometimes
several) sensors. Each such sensor network node has typically several
parts: a radio transceiver with an internal antenna or connection to an
external antenna, a microcontroller, an electronic circuit for interfacing
with the sensors and an energy source, usually a battery or an
embedded form of energy harvesting.
CHALLENGES
 1) Resource constraints
 2) Dynamic topologies and harsh environmental conditions
 3) Quality-of-service (QoS) requirements
 4) Security
 5) Large-scale deployment and ad hoc architecture
 6) Integration with Internet and other networks
And More… e.g.
 7) Data redundancy
 8) Packet errors and variable-link capacity
DESIGN GOALS

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

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1) Low-cost and small sensor nodes
2) Scalable architectures and efficient protocols
3) Data fusion and localized processing
4) Resource-efficient design
5) Self-configuration and self-organization
6) Time synchronization
7) Fault tolerance and reliability
8) Secure design
And More… e.g.
 9) Adaptive network operation
 10) Application-specific design
CHALLENGES VERSUS
DESIGN GOALS
Challenges Versus Design Goals in IWSNs
DESIGN PRINCIPLES AND
TECHNICAL APPROACHES

The design principles and technical approaches in
IWSNs are broadly classified into three categories:
 1) Hardware development;
 2) Software development; and
 3) System architecture and protocol design
HARDWAR DEVELOPMENT
 1) Low-Power and Low-Cost Sensor-Node Development
1) Sensor
Four basic components
2) Processor;
of industrial sensor node 3) Transceiver;
4) Power source
 2) Radio Technologies
 3) Energy-Harvesting Techniques
SOFTWARE DEVELOPMENT

1) Application Programming Interface (API)
In IWSNs, the application software should be accessible
through a simple application programming interface
(API) customized for both standards-based and
customer- specific requirements

2) Operating System and Middleware Design
very critical to balance the tradeoff between energy and
QoS requirements. TinyOS is one of the earliest
operating systems
Introduction to IWSN standards:
Zigbee and WirelessHart

Both Zigbee and WirelessHart share IEEE 802.15.4 as
the basis of their Physical and Data Link layer in the Open
System Interconnection model (OSI model)

The 802.15.4 standard defines a communication layer at
level 2 in the OSI model and uses 27 frequency Channels:
 868.0 - 868.6MHz -> 1 channel
 902.0-928.0MHz
 2.40-2.48GHz
(Europe)
-> 10 channels (USA)
-> 16 channels (Worldwide)

The reason that IEEE 804.15.4 has a good
performance against noise is that the information is
modulated using Direct Sequence Spread Spectrum
(DSSS) technique before being sent to the physical
layer in this standard.

Encryption is one of the basic services provided by
Zigbee (application and network keys implement extra
128b AES encryption). This is the reason that Zigbee shows
a better performance in secure data transmissions.

On the other hand, the WirelessHart standard shows a
better performance in real-time data transmission in
industrial platforms compared to Zigbee. Moving up to the
network layer, WirelessHART represents a true mesh
network, with each node capable of serving as a router.
Wireless Sensors Using Zigbee and WirelessHart Standards
Electrochem FS1, Wireless Flow Sensor Using Zigbee Standard
Patent-Pending PS1, Wireless Pressure Sensor Using Zigbee Standard
The SITRANS P280 wireless pressure sensor
• Supports the WirelessHART standard (HART V 7.1)
• Very high security level for wireless data transmission
• Optimum display and readability using graphical
display(104 x 80 pixels) with backlight
• Stand-by (deep sleep phase) can be activated and
deactivated with push of a button
• Battery power supply, Battery service live up to 5 years
• Optimized power consumption through new design,
and increase in battery service life
• Can be used for absolute and gauge pressure
measurements

Emerson Process Management has developed a
Smart Wireless Network using WirelessHart products
which is automating temperature and flow
monitoring to increase production on the company’s
Gullfaks offshore platforms in the northern part of the
Norwegian North Sea. Needing a monitoring
approach able to be installed without interrupting
flow, operators are using wireless devices to transmit
real time data that monitors temperature and flow.
The developed WSN is allowing quick reaction to any
loss of well pressure and maximizing throughput from
the well.

A loss in wellhead pressure was occasionally causing in flow losses
from the producing wells at Gullfaks A, B and C platforms which
belong to StatoilHydro, the leading oil and gas operator on the
Norwegian continental shelf.

Since there were no flow-metering devices installed within the well
pipes, it was very difficult to detect the loss of flow. Installing such
devices for this application was not practical as this would require a
complete shutdown of production, which would be far too expensive in
terms of lost throughput.

Needing to automate the monitoring so as to provide real-time
data, while also reducing personnel presence in hazardous
areas, StatoilHydro initially implemented a pilot installation on the
Gullfaks A, B & C platforms. Wireless transmitters were installed to
indirectly indicate temperature and flow on lines at each of forty
wells.

The temperature range on the flowline surfaces of interest at
Gullfaks A is about 50-70°C during normal operation. A lower
threshold limit is usually set in the Process Control and Data
Acquisition (PCDA) system. When temperature drops to this value,
an alarm is triggered to indicate a pressure loss. The threshold value
varies slightly from well to well, depending on the well
characteristics. The table on next slide shows examples of operating
temperatures and lower threshold values (alarm limits) for four
wells at Gullfaks A.
Well operating temperatures and alarm limits
Well
Operating temp., °C
Alarm limit, °C
1
68
63
2
63
55
3
55
52
4
59
55
Lab Tests

Deployment and installation of equipment at an offshore platform
is a costly and time-consuming procedure. To ensure that the chosen
system compiled with the Gullfaks requirements, the system was tested
in the laboratory facilities at StatoilHydro’s research center in
Trondheim, Norway, using real-size replicas of equipment used in
StatoilHydro’s installations.

The test network comprised five wireless transmitters and one
gateway. It was deployed and monitored for about 40 hr. The wireless
transmitters were positioned to provide a challenge to the capabilities
of the network, especially regarding wireless communication in areas
with lots of metal structures and no direct line-of-sight conditions.
Next slide shows the lab network topology.
The lab network topology at the end of the test period

The network performance (latency, stability and reliability) is
shown in figure below. The network has an initialization phase of about
1-2 hr, during which the mesh network topology is created and the
optimal routes are chosen based on a tradeoff between high
stability/reliability and low latency. After this initial phase, the network
remained stable for the duration of the test period. The latency varied
from about 1.5 sec. to 2 sec., the stability ranged 96-100%, and the
reliability remained at 100% for the entire test period.
Integration with Process Control and Data Acquisition
(PCDA) system

Transmission of digital
measurement data from the
gateway to the PCDA
system is based on the
Modbus serial protocol. A
wired communication link
from the gateway to a
Modbus interface in the
PCDA controller node was
installed which is shown
here.
Conclusion

In contrast with the once-a-shift manual recordings, Emerson’s
wireless devices now transmit readings every 30 seconds back to the
Smart Wireless Gateway. The gateway is hardwired straight into the
existing control system providing operators with the real time
information they need to react quickly to any change in flow.

The combination of quicker and more reliable detection of lost
flow enabled by the WSN, and the gained possibility of prompt action
to reestablish flow, has an estimated annual net present value of $40
million for the Gullfaks A offshore facility. The network performance of
the WSN solution has fulfilled the application requirements, providing
practically 100% reliability with the acceptable latency. This shows that
WSNs are fully capable of robust and reliable communication in the
harsh environment found on offshore platforms.
Thanks for your patience and
attention…