Overview
A wireless sensor network (WSN) is a wireless network consisting of spatially distributed autonomous devices using sensors to cooperatively monitor physical or environmental conditions, such as temperature, sound, vibration, pressure, flow, level, motion or pollutants, at different locations.
Wireless sensor networks are now used in many industrial and civilian application areas, including industrial process monitoring and control, machine health monitoring, environment and habitat monitoring, healthcare applications, home automation, and traffic control
What it is?
Unique characteristics of a WSN include:
Limited power they can harvest or store
Ability to withstand harsh environmental conditions
Ability to cope with node failures
Mobility of nodes
Dynamic network topology
Communication failures
Heterogeneity of nodes
Large scale of deployment
Unattended operation
Applications
Applications
Applications
1
1 1
1
Application
50 nodes on 4 th floor
5 level ad hoc net
30 sec sampling
250K samples to database over 6 weeks
Sensor nodes
Nodes can be imagined as small computers, extremely basic in terms of their interfaces and their components. They usually consist of a processing unit with limited computational power and limited memory, sensors (including specific conditioning circuitry), a communication device (usually radio transceivers or alternatively optical), and a power source usually in the form of a battery.
Base Station
The base stations are one or more distinguished components of the WSN with much more computational, energy and communication resources. They act as a gateway between sensor nodes and the end user.
Wireless Sensor Network Advantages
Wireless systems allow for widespread energy saving, enabling preventative maintenance for reduced unplanned downtimes, increasing productivity, and saving on wiring costs—all with lower upfront investments versus a wired system.
Wireless Sensing Solution
Wireless Sensing Solutions are a new means to satisfy demanding data measurement requirements in a range of industrial environments. Without the use of common cables, power supplies or data acquisition equipment, our selfpowered real-time solutions can be as remote and customized as you need them to be.
Providing accurate data in remote and at times unsafe locations, wireless sensors measure, record and transmit data—in real time—in critical applications such as oil and gas drilling, food and beverage production, metal fabrication and machining, chemical, paper and pulp processing, along with other manufacturing applications. Built for durability, sensors can withstand the harsh and dirty conditions of these often dangerous and hazardous environments.
TinyOS is a free and open source component-based operating system and platform targeting wireless sensor networks (WSNs).
TinyOS is an embedded operating system written in the nesC programming language as a set of cooperating tasks and processes. It is intended to be incorporated into smartdust.
TinyOS started as a collaboration between the University of
California, Berkeley in co-operation with Intel Research and Crossbow Technology, and has since grown to be an international consortium, the TinyOS Alliance.
Wireless Instrumentation
Wireless Instrumentation
Wireless instruments will not replace those in traditional wired (4 to 20 mA or fieldbus) installations but, in many ways, they complement traditional versions by offering an economical solution for difficult applications.
Initial applications of wireless instrumentation will be for monitoring processes and managing assets. Some time in the future, wireless instrumentation may be used in control applications but this will require modification to PID algorithms, appropriate risk analysis and good, fail-safe design practices.
Select wireless instrumentation if you need to:
Monitor instrument condition remotely
Re-range or carry out instrument configuration changes remotely
Monitor process data that has been uneconomical to measure in the past
Monitor process data over a short term to solve process problems
WirelessHART is a wireless mesh network communications protocol for process automation applications. It adds wireless capabilities to the HART Protocol while maintaining compatibility with existing HART devices, commands, and tools.
Low cost installation
Low risk upgrade
Reduced configuration time
Improved production
Improved maintenance
Highly secure communication
Low Power and Energy
Compatible with other systems base on HART applications
TinyOS-2.x
A nesC application consists of one or more
components assembled, or wired, to form an application executable.
A component provides and uses interfaces.
There are two types of components in nesC: modules and configurations.
Modules provide the implementations of one or more interfaces.
Configurations are used to assemble other components together, connecting interfaces used by components to interfaces provided by others.
TinyOS-2.x
BlinkAppC.nc
configuration BlinkAppC {
} implementation { components MainC, BlinkC, LedsC; components new TimerMilliC() as Timer0; components new TimerMilliC() as Timer1; components new TimerMilliC() as Timer2;
BlinkC -> MainC.Boot;
BlinkC.Timer0 -> Timer0;
BlinkC.Timer1 -> Timer1;
BlinkC.Timer2 -> Timer2;
BlinkC.Leds -> LedsC;
}
TinyOS-2.x
BlinkC.nc: module BlinkC { uses interface Timer<TMilli> as Timer0; uses interface Timer<TMilli> as Timer1; uses interface Timer<TMilli> as Timer2; uses interface Leds; uses interface Boot;
} implementation { event void Boot.booted() { call Timer0.startPeriodic( 250 ); call Timer1.startPeriodic( 500 ); call Timer2.startPeriodic( 1000 ); } event void Timer0.fired() { call Leds.led0Toggle(); } event void Timer1.fired() { call Leds.led1Toggle(); } event void Timer2.fired() { call Leds.led2Toggle(); }
}
TinyOS-2.x
Case Study
Intelligent Buildings
Case Study
Shop Floor
As a conclusion It’s clear to understand that any changes from conventional to high-tech systems will lead to increase the performance of the system, simplicity and decreasing the cost of implementation.
On the other hand, in the harsh environment, utilizing the WSNs are preferred.