Download - Wireless Vision
WI-VI TECHNOLOGY
1
A Presentation on
ByShashidhar.S.K
CONTENTS
Introduction
Wireless vision
Eliminating the flash effect
Identifying and tracking humans
Applications, Merits and Demerits
Conclusion
Reference
2
INTRODUCTION
3
Wi-Vi stands for wireless vision.
Wi-Vi is used to detect the humans behind the wall.
Wi-Vi is a three antenna device with two transmitters and one receiver.Signals transmitted are similar but inverse of 1st antenna.
Earlier operation to detect humans behind wall used antenna array and UWB frequencies made them bulky.
Key Idea
WI-VI DEVICE
Figure1 :Key idea for working of WI-VI
4
The key idea behind this technology is the reflection of the signals which is similar to that of RADAR and SONAR imaging.
WIRELESS VISION
Captures moving objects behind wall Makes use of WI-FI signals and hardware Uses WI-FI signals ISM bands at 2.4Ghz but limits
to 20 MHz After traversing the wall twice the signal power is reduced by 3-5 orders of their magnitudeThe reflections from the wall is much more stronger
than that of humans this reflection overwhelm the signals reflected from the human and prevents it from registering minute variations called as FLASH EFFECT
5
Figure 2: Wi-Vi Setup
WHERE TO INSTALL THE DEVICE ?
6
ELIMINATING THE FLASH EFFECT
There are three steps involved Initial nulling Power boosting Iterative nullingThese combined process is known as MIMO nulling
7
8MIMO CASES
θ
Antenna Array
Direction of motion
At any point in time, we have a single measurement
Direction of reflection
WI-VI DEVICE
IDENTFYING AND TRACKING OF HUMANS
Figure 5:ISAR 9
θ
Antenna Array
Tracking Motion
Direction of motion
Direction of motion
θ
WI-VI DEVICEFigure 6:ISAR 10
Identifying and tracking humans
One moving person is indicated by a single curved line
Figure 7: output for single human 11
Tracking Multiple Humans
Number of distinct curves at the same time corresponds to the number of humans
Figure 8 output for two Humans 12
Figure 9 output for three Humans
Figure 10: Detection Accuracy of Wi-Vi for Different Types of Obstructions
13
ApplicationsFigure 11:Law enforcement
Figure 12:Emergency situations
Figure 13:Personal security Figure 14:Gesture interface from behind a wall
14
Merits High efficiency. Low power, low cost and low bandwidth. It overcomes the need for UWB by using MIMO nulling to remove the flash effect. No connectors. Ease of installation.
Demits Low resolution. Short range of communication.
15
CONCLUSION
Could prove to be very powerful and effective device for defence purposes.
Possibly the next generation RADAR.
Further improvement will allow WI-VI to become more expressive hence hoping new directions of virtual reality.
16
REFERENCE
[1] “See Through Walls with Wi-Fi!” by FadelAdibandDinaKatabi Massachusetts Institute of Technology {fadel,dk}@mit.edu.August 2013
17
[2] http://people.csail.mit.edu/fadel/wivi/
[3] http://geekshots.in/2013/12/16/wi-vi-wifi-vision-vision- behind-the-walls/
18