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SMART SENSORS
PRESENTED BYSWARNJEET KAUR
11092011M.TECH ECE
2ND Semester
SENSORS
An electronic device that produces electrical, optical, or digital data derived from a physical condition or event.
SMART SENSORS Smart sensors are sensors with integrated electronics that can perform
one or more of the following function logic functions, two-way communication, make decisions.
Usefulness of Silicon Technology in Smart Sensor
A smart sensor is made with the same technology as integrated circuits.
A smart sensor utilizes the transduction properties of one class of
materials and electronic Smart Sensors properties of silicon (GaAs). A
transduction element either includes thin metal films, zinc oxide and
polymeric films.
Integrated sensors provide significant advantages in terms of overall size
and the ability to use small signals from the transduction element. The IC
industry will get involved in smart sensor if a very large market can be
captured and the production of smart sensor does not require non-
standard processing steps.
Signal conversion effects
TABLE 1: Signal domain with different measurand
Table2-Signal domain with physical effects
Importance and Adoption of Smart Sensor
Cost improvement
Reduced cost of bulk cables and connectors
Remote Diagnostics
Enhancement of application
Self calibration Computation Communication Multisensing System Reliability Better Signal to Noise Ratio
Improvement in characteristics
Non-linearity Cross-sensitivity Offset
General Architecture of smart sensor
Types of Smart Sesnsors
Optical SENSORS Infrared Detector Array Acceleromete Integrated multisensor Bluetooth based smart sensors
WIRELESS SENSOR NETWORK
From the user point of view, querying and tasking are two main services provided
by wireless sensor networks .Queries are used when user requires only the
current value of the observed phenomenon. As wireless sensor networks are data-
centric networks, the user does not query a specific node for the information it
might provide, but defines data (type,location, accuracy, time, etc.) he/she is
interested in and requests it from all nodes that can provide the answer.
Gateway functionality Smart sensor nodes scattered in the field collect data and send it to users
via gateway using multiple hop routes.
Figure 2- Wireless sensor network
The main functions of a gateway are the following
Communication with sensor network - Short-range wireless communication is used
(Bluetooth, UWB, RF, IR, etc.). Provides functions like discovery of smart sensor
nodes, generic methods for sending and receiving data to and from sensors, routing,
etc.
Gateway logic – Controls gateway interfaces and data flow to and from sensor
network. It provides an abstraction level with API that describes the existing sensors
and their characteristics; provides functions for uniform access to sensors regardless of
their type,location or network topology, inject queries and tasks and collect replies.
Communication with users – Gateway communicates with users or other sensor
networks over the Internet,wide area networks (GPRS, UMTS), satellite or some
short-range communication technology.
Communication With Users
Gateway communications with users or other sensor networks over the Internet,
WAN, Satellite or some shortage communication technology.From the user point
of view, quering and tasking are two main services provided by wireless sensor
networks. Queries are used when user requires only the current value of the
observed phenomenon. Tasking is a more complex operation and is used when a
phenomenon has to be observed over a large period of time.Both queries and
tasks of time to the network by the gateway which also collects replies and
forwards them to users.
BlueTooth
Blue tooth operates in the unlicensed ISM band at 2.4 GHZ frequency band and
use frequency hopping spread spectrum technique. A typical Blue tooth device
has a range of about 10 meters and can be extended to 100meters.
Communication channels supports total bandwidth of 1 Mb / sec. A single
connection supports a maximum asymmetric data transfer rate of 721 KBPS
maximum of three channels.
Smart Sensor Node Architecture
Discovery Of The Smart Sensor Nodes
Smart sensor node discovery is the first procedure that is executed upon the gateway
installation. It goals to discover all sensor nodes in the area and to build a list of sensor's
characteristics.
When the gateway is initialized, it performs bluetooth inquiry procedure. When the blue tooth
device is discovered, the major and minor device classes are checked. These parameters are
set by each smart node to define type of the device and type of the attached sensors. Service
class field can be used to give some additional description of offered services. if discovered
device is not smart node it is discarded. Otherwise service database of the discovered smart
node is searched for sensor services.Once connection strings is obtained from the device. Blue
tooth link is established and data exchange with smart mode can start.
CONCLUSION
In conclusion, silicon is very suitable material for fabrication of smart sensors.
But still a lot of research is required to get benefits of the smart sensor but from
the experience of already existing devices, we can expect that in the coming
decade a large number of successful smart sensors will emerge.Bluetooth is a
possible choice for data communication in sensor networks. Good throughput,
low-power and low-cost.
THANKS