Page 134 - Advances In Productive, Safe, and Responsible Coal Mining

118 Advances in Productive, Safe, and Responsible Coal Mining

separation distance to only 2.0in. (5.1cm) needed to prevent EMI effects; however,
underground testing at one mine showed an increased EMI effect from the use of the
pouch. The mine had mesh on the roof and ribs in the mine section used for testing.
Depending on the position around the machine, the shielded pouch could actually
cause EMI to be experienced at separation distances of up to 13in. (33.0cm). This
phenomenon is under investigation as of the writing of the chapter.

7.6.2 Hybrid proximity systems
NIOSH researchers have identified a number of alternative sensing technologies that
could improve or complement existing PDS. Section 7.2 described these technologies.
It is possible that an improved PDS will be a fusion of a number of sensing technol-
ogies, as opposed to a single technology system.
An example of an existing sensor fusion PDS system is the Becker Collision
Awareness System (CAS), which is a PDS used internationally. The Becker CAS
is based on EM to provide coverage close to the machine, high-frequency RFID to
provide coverage beyond the close range, and an ultra-high-frequency (UHF) RFID
to provide long-range coverage. This system utilizes the advantages of each technol-
ogy to provide a robust system to prevent accidents from occurring.
Sensor fusion systems could consist of a combination of EM, cameras with com-
puter vision, and radar such that multiple measurements are utilized for detection.
These systems could be utilized to provide redundant detection and ranging with
validation. Radar could mitigate some of the environmental and EMI effects that
hinder the performance of EM systems, while cameras with computer vision could
provide validation of obstacle detection, and the EM could provide coverage through
brattice cloth and around corners.

References

[1] Ruff T. Recommendations for evaluating and implementing proximity warning systems
on surface mining equipment. Spokane, WA: Department of Health and Human Services,
Public Health Service, Centers for Disease Control and Prevention, National Institute for
Occupational Safety and Health, Spokane Research Laboratory; 2007.
[2] Chirdon D. MSHA proximity detection, Available from: http://www.msha.gov/Accident_
Prevention/NewTechnologies/ProximityDetection/Proximity%20Detection%20Paper.pdf;
2009. Accessed 25 October 2010.
[3] Moore P. Camera ready. Min Mag 2009;199(3):34–5.
[4] MSHA. “Proximity detection systems for continuous mining machines in underground
coal mines: notice of proposed rule making.” Mine safety and health administration.
Fed Regist 2011;76(169):54163–79. August 31.
[5] Johnson G, Griffin R, Laage L. Improved backup alarm technology for mobile mining
equipment. Pittsburgh, PA: United States Department of the Interior, Bureau of Mines;
1986 Information Circular (IC) 9097.
[6] Schiffbauer W. Active proximity warning system for surface and underground mining
applications. Min Eng 2002;54(12):40–8.