Low Frequency Underground

Communications

Group 12 <=> Subterranean Fourier TransformersChris Springer, Andrew Duncan, and Adam Kassar

Outline

Problem Statement Needs Project Background

Overall Architecture Level Zero Architecture Level One Architecture

Major Technologies Creative Aspects Challenges to System Development Outcomes Conclusion

Problem Statement

Meet a clearly articulated need to save the lives of trapped miners during mining incidents

Continue the work of current and past EE 480/481 groups

Needs

Statistical Support Coal Mine Fatality Statistics Coal Mine Fatality Rate Plot

Psychological Impact Trapped situation due to mine collapse

burdens the miners Example

▪ PTSD (Post Traumatic Stress Disorder) Communications device proposed reduces

amount of time trapped underground

Needs-Coal Mine Fatality Statitiscs

Year Miners Fatalities Year Miners Fatalities Year Miners Fatalities

1982 241,454 122 1992 153,128 55 2002 110,966 28

1983 200,199 70 1993 141,183 47 2003 104,824 30

1984 208,160 125 1994 143,645 45 2004 108,734 28

1985 197,049 68 1995 132,111 47 2005 116,436 23

1986 185,167 89 1996 126,451 39 2006 122,975 47

1987 172,780 63 1997 126,429 30 2007 122,936 34

1988 166,278 53 1998 122,083 29 2008 133,828 30

1989 164,929 68 1999 114,489 35 2009 134,089 18

1990 168,625 66 2000 108,098 38 2010 135,500 48

1991 158,677 61 2001 114,458 42 2011 143,437 21

Needs-Coal Mine Fatality Rate Plot

1980 1985 1990 1995 2000 2005 2010 20150.01

0.02

0.03

0.04

0.05

0.06

0.07

Years from 1982-2011

Coal M

ine F

ata

lity R

ate

(%

)

Coal Mine Fatality Rate with Respect to the Year from 1982-2011

Ranking of Needs

Meet safety regulations All MSHA CFR 30 Standards

Rugged Must be able to withstand impacts and physical

abuse Compact/Lightweight

Miners must be able to carry a large amount of equipment into cramped areas

Low Power Unsafe for high power signal broadcasting Ensures long battery life

Project Background

Communicating with miners is as old of a problem as the occupation itself

No two-way underground-surface communication system currently exists

Background Continued…

Two way through the earth communication is not possible with current technology High radio frequencies (RF) scatter when

propagating through the Earth’s crust Wide band transmissions are below the

noise floor and thus non-detectable Proposed Solution

Spread Spectrum at Ultra Low Frequencies (ULF)

Background Continued…

Durkin, John. "Assessmentment of Present Electromagnetic Techniques for the Location of Trapped Miners." 1980.

Background Continued…

Current Technologies approved by MSHA (Mine Safety and Health Administration) Walkie-Talkies Leaky Feeder Communication Systems Mine Page Phones RFID (Radio Frequency Identification)

Tracking Systems PED (Personal Emergency Device)

Background Continued…

Chilean mine collapse of 2010 33 miners trapped underground Took 17 days to find them

▪ Why?

System Design

Overall Architecture Level Zero Architecture Level One Architecture Level Two Architecture

Use Case User Interface Specification

Keypad LCD (Liquid Crystal Display) Screen

Dataflow Diagram State Transition Diagram Circuit Diagram

Level Zero Architecture

Level One Architecture

Level Two Architecture

Use Case

User Interface

Dataflow Diagram

Circuit Diagram

Major Technologies

Magister Field Programmable Gate Array (FPGA)

hardware used to interface other cards with a PC via USB

Major Technologies

Janus Analog-to-Digital converter Digital-to-Analog converter

Creative Aspects of Solution Use Existing Open Source HAM Radio

Software/Hardware PowerSDR GNURadio Janus/Magister Cards

Digital Signal Processing Algorithm Spread spectrum Detect low-power signals at Ultra Low

Frequencies

Challenges and Uncertainties

Low power Ultra Low Frequency

Needed for through the earth propagation

Product Size Mine Safety and Health Standards Completing project on time

Expected Outcome

Lab bench prototype Able to send and receive ASCII

characters Operate in an electrically-noisy

environment

Project Plan

Task Week Number in Semester 2

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16

Crash course on related technologies (languages, hardware usage)

Review/Understand previous work

Implement Signal Processing Algorithim

Implement Spread Spectrum Design

Implement Sending

Implement Receiving

Lab bench testing

Actual Testing

Verfication Testing

Error fixing

Component Procurement List

Name Price Quantity Possession Status

Janus Board NA 2 EE 481 already obtained Will pass on to us

Metis Board NA 2 EE 481 already obtained Will pass on to us

Atlas Board NA 2 EE 481 already obtained Will pass on to us

Power Supply Unit NA 2 EE 481 already obtained Will pass on to us

SDR 1000 NA 2 EE 481 already obtained Will pass on to us

Conclusion

The digital signal processing portion of the project will be the central focus of our work

A lab bench prototype is anticipated to be produced by the end of our work and fully tested Transmit and Receive from both ends of

the prototype

Questions?