Made By : Pranay Sharma

Dictionary Meaning : “A determination of the place where something is.”

OR“Accurately specifying the position of an

object within a given Local Area” It can be thought of as a “G.P.S.” at a MICRO

Level”

A low bandwidth wireless communication technology which consumes very less energy

It is based on the 802.15.4 which is a standard for wireless communication put out by the IEEE

Zigbee 1(Stationary Device) Zigbee 2(Mobile Device)

Step One: Transmission takes place

Step Two: The RSSI(receive Signal Strength Indicator) or simply SIGNAL STRENGTH value is noted by Zigbee 1

e.g. Let RSSI=23db ~ ~ 1m Radius

A Microcontroller then determines from a stored

database how much distance is equalent to 23db (a fictious table is shown in the next slide)

So the database tells the microcontroller that 23db ~ 1m distance from the ~ 1m distance from the stationary stationary

Eg. Of such an equivalency table*Sno.Sno. Signal Signal

StrengthStrengthDistaDistancence

11 23db23db 1m1m

22 20db20db 2m2m

33 18db18db 3m3m*=An assumed table, values are just assumed to explain the point.

So using one Stationary Module and one mobile module an APPROX AREA* can be assumed in which the mobile Zigbee module might be assumed to be LOCATED as shown below.(Refer to the previous figure for Zigbee colour code meaning).

23db 23db ~~1m1m

*=The shape assumed here is a circle ,though the real shape of this probabilistic area might not be a circle at all

And by using other techniques or algorithms like triangulation etc ,it should be even possible to find out the position of a mobile Zigbee ( ) sensor ,Though it shall be under the constraint of limited Accuracy.

What does it Do?Detects no. of times a person has fallen, sat down,

slept/lied down etc Relays this information through a DDS through an

R.F.(or in future Zigbee)

Hmmm….So what…I think its Enough….Is it?

But the Question is ,where did the person Fall?? Or Did he even Fall??

He could have EVEN just Sunked onto his SOFT Couch!!!

The Device Says that Mr.X slept ??But where ??Is He Sleeping on his bed or Slowly just fallen onto his floor?

Moreover for people with disorders like “Dementia” & “Sleep walking” the question also arises of where are they right now?

It “probably” might be able to locate people to within a limited area….so??Can be used for security purposes as people

can be tracked remotelyFor children tracking in “Child day care

schools”Asset tracking in Industries.Robot localization.

Projects that can be enhanced in your labFall Detection Project (Gary)Tracking of People Moving in a MuseumChild tracking in a play-school.Robot-Localisaiton.

Localization has been tried using several methods:-

a) MIT labs made devices like “Cricket Ultrasonic sensors” for localisation

b) Company ”Ekahau” uses Wi-Fi devices for localization.

c) Dep't of Computer Science & Information Engineering, NTU, Taiwan also had similar projects related to localization.