Abstract: [The overview of the image sensor for optical signal and position detector. The example of application systems also are presented.

Transcription

1 Project: IEEE P Working Group for Wireless Personal Area Networks N (WPANs) Submission Title: [Location Information Technology by LED Tags and Image Sensors] Date Submitted: [8 May 2008] Source: [(1)Shuji Suzuki, /NEC] Address [(1)1753 Shimonumabe Nakahara-ku Kawasaki Japan] Voice:[(1) ] [(1) s-suzuki@dl.jp.nec.com] Re: [] Abstract: [The overview of the image sensor for optical signal and position detector. The example of application systems also are presented.] Purpose: [Contribution to IEEE SG-VLC] Notice: This document has been prepared to assist the IEEE P It is offered as a basis for discussion and is not binding on the contributing individual(s) or organization(s). The material in this document is subject to change in form and content after further study. The contributor(s) reserve(s) the right to add, amend or withdraw material contained herein. Release: The contributor acknowledges and accepts that this contribution becomes the property of IEEE and may be made publicly available by P

2 Location Information Technology by LED Tags and Image Sensors / NEC

3 Contents Optical signal detection by Image sensor Advantage and disadvantage of Image sensor Frame structure of optical ID Signal processing block-diagram Application system overview Application of security for children Application for warehouse management Location measurement accuracy Comparison of location measurement technology 2

4 Optical signal detection by Image Sensor (Video Camera) Optical signal of LED Tags t LED Tag Sampling by Image sensor Optical signal bitrate:40bit/sec Image sensor : 120fps(frame per second) PC for signal processing 3

5 Advantage of Image Sensor as an Optical signal detector Sun light Multiple optical signal sources 2 dimensional CMOS/CCD Sensor Capability of Space-Division Multiplexed data transmission and position detection Optical Lens Capability of interference rejection Disadvantage of Image Sensor : Low signal speed 4

6 Example of optical ID Frame structure 40bit SOP ID CRC 8bit 24bit 8bit SOP(Start Of Pac ket) 8bit Fixed pattern ID 24bit Arbitrary data CRC 8bit Cyclic Redundancy Che ck 5

7 Signal processing block-diagram doc.: IEEE < > Optical signal detection Image buffer memory Video Capture (120fps) 30 fps Image data files Optical ID detection Optical ID position detection by spatial filtering Detected ID and their location information files 6

8 Application system overview Network doc.: IEEE < > Image Sensors Image Processing (ID detection, Location LED Tags User application Location Information DB ID Information DB Detection of employee ID Security for children Warehouse Management 7

9 Application of Security for children Image sensor = Optical ID reader + Video Camera RF-ID + Security Camera LED tags + Image sensor ID:yyyy ID:xxxx Which one is Mary? She is Mary! ID:cccc dddd ID:aaaa bbbb 8

10 Application for Warehouse Management Image Sensor at high position LED Tags with optical ID Location measurement of LED tags with accuracy higher than RFID 9

11 Demonstration of Warehouse Management doc.: IEEE < > Image Sensors PC Two LED tags for Direction Finding WLAN Location and Direction information Image Sensor Hand Over 10

12 VGA Image Sensor Location measurement accuracy doc.: IEEE < > Example: 640 x 480 pixels (VGA) resolution 1.25cm resolution for 8m x6m Plus Measurement error of distortion by optical lens Experimental Results Target LED Tags 5cm resolution for 8m x 6m plane with equalization software for lens distortion 6m Pretty good measurement accuracy 8m 11

13 PC Image Sensor with zoom lens doc.: IEEE < > Experiment for Long Distance Zoom lens is effective for long distance application 50m Detected Optical ID 12

14 Example of Employee ID detection ID = B ID = C ID = A 13

15 Comparison of Location Measurement Technology RF Image Sensor Accuracy Effect of direct blinders Effect of metric circumstances Measurement system stability /X /X Depend on RF transmission circumstance Just avoid direct blinders! 14

16 Q&A 15