Post on 02-Jan-2016
Implementation of MINER Act for Implementation of MINER Act for Communication and Tracking Using Communication and Tracking Using MSHA’s Program Policy Letter (PPL) MSHA’s Program Policy Letter (PPL)
P09-V-01 as GuidanceP09-V-01 as Guidance
Salwa El-BassioniElectrical Engineer
May 14, 2009
MINER Act RequirementsJune 15, 2006
• A redundant means of communication with the surface, such as secondary telephone or equivalent two-way communication.
• Above ground personnel to determine the current, or immediately pre-accident location of all underground personnel.
MINER Act RequirementsJune 15, 2009
• Post-accident communication between underground and surface personnel via wireless or alternative to wireless, PPL provisions.
• Electronic tracking system to determine location of persons trapped underground
Untethered Devices
• One device for each group of miners working or traveling together.
• One device for any miner working or traveling alone.• How many would we need on a working section?
– One device for each group working or traveling together and one device for each miner working or traveling alone. For example; on advancing sections, each CM operator, roof bolter crew, and scoop operator would need their own device.
Coverage for Two-Way Communications
• Throughout the working section.– Miners inby the loading point are able to communicate
with the surface.
• Continuous in each escapeway.– Primary and secondary.
• 200 foot zone inby and outby strategic areas.– Strategic areas = where miners are normally required
to work or likely to congregate in an emergency.
Coverage ComplianceMesh System
Components of a mesh system:• Untethered devices (radios).• Nodes (wired/wireless or both).• Antennas• Power supplies.• Gateway nodes, hub or controller on the surface.• Communication facility on the surface for monitoring
network.
Note: power supplies used in areas where permissible equipment is required must be IS or in X/P enclosures.
Two-way Communication Coverage
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Sectio
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Primary EscapewaySecondary Escapeway
Node/ Antenna
Feeder
Belt
Coverage Compliance LF System
Components of a Leaky Feeder:• UHF and VHF Radios• Power supplies • UHF amplifier• VHF amplifier• Surface base stations• Splitters• Antennas• Termination units
Note: power supplies used in areas where permissible equipment is required must be IS or in X/P enclosures.
Leaky Feeder
Miner 1 Transmitting
Miner 2 Receiving
Radiating Mode
Coupled Mode
Functions as a power line, communications link, and a distributed antenna
Leaky Feeder: CM Section
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Sectio
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Primary Escapeway
Secondary EscapewayFeeder
Antenna
Belt
Leaky Feeder
Coverage ComplianceMedium Frequency (MF) System
Components of MF system:
• Conductors in a mine (track, metal pipes..)
• Hand held radios
• Base transmitter (transceiver in central area)
• Repeaters (transfers frequency)
• Node (repeater used in a network)
Coal Seam
Metal Pipes/Conduits
Tracks/Rails
Medium Frequency (MF) Radio Communications
• Doesn’t require special cable.• Radio signal couples to other conductors to increase
range.
• UHF signal is converted to/from MF signal
• MF Signal is carried by un-powered conductive infrastructure in mine
Medium Frequency RepeaterMedium Frequency Repeater
Survivability
Redundant pathways to surface:
• One system with two or more pathway to the surface.
• Two or more systems installed in two or more entries and different pathways to the surface.
Belt
Track
Antenna
UHF LF Cable - Trunk 1
Escapeway
Two Leaky Feeder systems in multiple entries
UHF LF Cable - Trunk
2
Belt
Track
Low-cost LF Cable
Antenna
UHF LF Cable
Escapeway
Coverage extension using low-cost cables and antennas
Electronic Tracking Coverage
Types of tracking:
• Zone-based– RFID tags and readers
• RSSI -based – Using nodes as those from communication
system.
Miner A
Miner B
RFID Reader
Operation of conventional RFID:• Reader senses tags that are
within range• Tag transmits a unique ID• Detected tag IDs are sent to
the surface
• Tag location is associated with the reader’s known location and displayed on the tracking computer
Tag
Miner A
Miner B
RFID ReaderTag
Operation of reverse RFID:
• Tags transmit RFIDs
• Reader receive RFID from tag(s)
• RFID from reader & tag transmitted to comms system
• Comms system relays reader and tag information to surface
• Tracking computer calculates and displays reader positions
Leak
y Fee
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Electronic Tracking Guidance
• Coverage in working section within 200 feet – Readers or nodes are 400 feet apart.
• Coverage in escapeways– Readers or nodes every 2000 feet
• Coverage in strategic areas– Within 200 feet of where miners are normally required
to work or likely congregate in an emergency.– Belt drives, loading points, SCSR caches, etc.
RSSI-Based Tracking(Node-based Systems)
• Error = difference between estimated and actual location.
• MSHA expects that errors in tracking locations may exist and will work with mine operators until compliance with the MINER Act is gained.
Zone-Based Tracking(Reader-based Systems)
Conventional and Reverse RFID
Error = difference between reported and actual position
• Accuracy of tracking is affected by:– tracking system update rate– motion of miners – reader or tag spacing – Interference
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Sectio
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2,000 ft.
400
ft.
400 ft.
Feeder
Secondary EscapewayPrimary Escapeway
Node / Reader
Belt
Electronic Tracking Coverage
Electronic Tracking Coverage: Longwall
2,000 ft.
2,000 ft.
400 ft.
400 ft.
Secondary Escapeway
Primary Escapeway
Node / Reader
Emergency Response Plan ERP
• No later than June 15, 2009 the ERP must, among other things, provide for:
• Post accident two-way communications
• Electronic tracking
Content of ERP
ERP will be reviewed on a mine-by-mine bases. Reviewers will be evaluating the following:
Wireless communication systems
• Type of system (LF, mesh, Wi-Fi, MF)
• Survivability, how it provides redundancy
Content of ERP(continued)
– Provisions for untethered devices• Accessibility to miners• Text, voice or both• Standby power• Approved (approval #)
Content of ERP(continued)
– Provisions for infrastructure• Type of components (LF, nodes, AP)• Approved components (approval # if applicable)• Location in the working section• Location in escapeways• Location relative to strategic areas• Power supply evaluation # if applicable.
Content of ERP(continued)
Electronic tracking system• Type of system, reader or node-based
– Location of tags– Location of readers or nodes in working section– Location of readers or nodes in escapeways– Location in strategic areas
• Vendor if known• Model number if known• Approval number if known• Standby power for infrastructure• Standby power for tags
Content of ERP(continued)
Surface provisions to address:• Standby power• Communication with and monitoring of
undergrond personnel • Uniquely identifying each miner• Location data is associated with time• How long the data is stored • Frequency of updating location data
Content of ERPContinued
• Maintenance provisions– Manufacturer plan– Restoring backup power
• Examination provisions– Weekly examination for infrastructure– Daily examination of tags and radios
• Backup plans– Communication system fails– Tracking system fails
Summary
• Survivability can be achieved by hardening the system or providing redundancy.
• One way to provide redundancy is to mix and match a primary (LF or mesh system) system with a secondary system ( MF or TTS).
• Error factors depend on system design, system installation, and computer algorithm being used.