bay area rapid transit gets global signaling presentation to “cbtc and beyond”: fifth...

Bay Area Rapid TransitBay Area Rapid TransitGETSGlobal Signaling

Presentation to

“CBTC and Beyond”: Fifth International Conference on Communications-Based Train Control

Washington, DC

May 7-8, 2003

BART’s AATC Project Status Update


Overview

· Project Status

· Next Steps

· Brief Recap of AATC Concept· Brief Recap of AATC Concept


Radio Ranging

Measure the round-trip propagation timeand calculate the distance.


Radio Ranging

Multiple measurements = Better accuracy

Ranging with Multiple Radios


Message Relaying


Track Circuits detect a train...

And the Station MUX sends speed commands to the train.

RELAY INTERLOCKING


RELAY INTERLOCKING

Existing interlockingreceives track circuit data...

…and sends permissive route data to the existing MUX


Overlay SystemA A T C I ntegr ation

AATC

STATIO NRADIO

S TA TIO NM U X

VHLCINTERLOCKING

TRACK SW ITCHES

CENTRAL CO NTRO L

RUNNINGRAILS

STATIONATO & SORS

S H U N T

TRACKSIDEMUX BO X

TRACKSIDEMUX BO X

TRACKSIDEMUX BO X

ATC

VEHICLERADIO

AAT C

T RACKSIDERADIO

T RACKSIDERADIO

Pow er

Pow er

CENTRAL CO NTRO L

S H U N T S H U N T

Ranging data provides train detection...

AATC sends train performancecommands via the radio network


Overlay SystemWhen the AATC system is complete...

…existing equipment will be removed.


Overview

· Brief Recap of AATC Concept

· Project Status

· Next Steps

· Project Status


Program Phases

Hayward Test Track

Fruitvale, Lake Merritt and the Wye

M-line thru Daly City

A-line thru Bay Fair

Phase 2(6/02)

Phase 3(7/05)

Phase 1(4/96)


Safety CertificationSafety Certification

Mixed Mode Certified for Revenue Service Effective July 1, 2002

Full Mode Certification deferred. As of July 1, 2002:– Dry-Run Tests Nearly Complete– Formal Tests, V&V and Report Remaining to

Complete


Phase 2 Accomplishments

Radio-based train location safety-certified Robust train-to-wayside communications

proven:– Continuous speed, acceleration/braking

commands achieved– Closed loop braking from wayside demonstrated

Run time savings proven Energy savings measured


AATC vs ATC - Fruitvale to Lake Merritt, A2 track

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Track Location (feet)

Spe

ed (

mph

)

AATC speedATC speed

Travel Direction

Train Speed vs. Location


AATC vs ATC - Fruitvale to Lake Merritt, A2 track

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10

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0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100

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Time (seconds)

Spe

ed (

mph

)

AATC speed

ATC speed

37 seconds

192

seco

nds

229

seco

nds

Train Speed vs. Time


Train speed (mph)

Line Current

kWh In

kWh Out

P Signal

Energy Measurements

Fruitvale to Lake Merritt -- ATC

Line Voltage

9.30 kWh

2.31 kWh


Train speed (mph)

Line Current

kWh In

kWh Out

P Signal

Energy Measurements

Fruitvale to Lake Merritt -- AATC

Line Voltage

7.81 kWh

1.66 kWh


Energy Measurements

Mode kWh In (Used)

kWh Out (Regen.)

Net Used

ATC 9.30 2.31 6.99

AATC 7.81 1.66 6.15

Savings (AATC vs. ATC)

16% 12%

Sample Runs Fruitvale to Lake Merritt (kWh/car)

Note: Energy regenerated depends upon other train traffic in area


Current Status

System is not yet in routine operations – Only 5 trains equipped– Operations Staff not yet trained– Need Test Director on-board– Special operating instructions


Remaining Design Issues

All remaining issues are in the adaptation of the technology to underlying train control system. For example:– Track circuit failure modes– Fuzzy track circuits limits, compounded by train

positioning margins– Integration with existing system (SORS)

Result is difficulty in locating a silent train in MANUAL if tightly “sandwiched” between two AATC trains


Operating Scenarios Thorough look at how system safety and performance

is affected by:– Loss of radio communication (silent train) – Equipment failure – Unusual or improper operations

30 years in AUTO. Fall back to MANUAL is inoperable and less safe. Need for hardened AUTO system.

Analysis could not have been done before target design was completed

Joint effort by Supplier, BART project team, and staff from Operations Control Center


Modifications Underway

Modify Silent Train Detection algorithms to use 2 track circuits instead of 1

Eliminate automatic transitions between AATC Mixed Mode and AATC Full Mode. However, still have fall back:– From AATC Full Mode to ATC with restricted speeds– From AATC Mixed Mode to ATC w/o restricted speeds

Position Accuracy improvements (partial) Tools for increased deployment efficiency


Pending Modifications (subject to funding) AATC Performance Improvements:

– Additional scope originally identified in 1999 but postponed until funding is available:

» Position Uncertainty (PU) Improvements» Reduced Brake Rate (RBR) Improvements» Slow Speed Orders

– Defer all but 1 of 8 potential PU Improvements Territory (Oakland Wye Retrofit, M-Line)


Fruitvale, Lake Merritt and the Oakland Wye

Hayward Test Track

Status of Phase 3 Status of Phase 3 Installation Installation

M-line thru Daly City 85 of 98 Radio Sites, VHLCs

at 5 Control Rooms

A-line thru Bay Fair 30 of 30 Radio Sites, VHLCs and SCs at 2 Control Rooms


Remaining Phase 3

Install wayside radios Install station computers in 5 TC rooms Collect radio ranging coefficients Perform database V&V at each location Install AATC equipment on 289 cars and 40 MV Training Revenue Service Preparation


Phase 2 Safety Certification June 2002

NTP Remaining Phase 3 August 2002

New test area ready (A30-A40) May 2003

Modifications Release #1 May 2004

Modifications Release #2 May 2005

Wye Re-layout Possibly Defer

Vehicle Retrofit May 03-Jan 2004

A-Line Ready (incl. Vehicles,Training) May 2004

M-Line July 2005 (Defer?)

Schedule


Summary

AATC concept is solid Interaction with existing system more

complex than expected Two key “Lessons Learned”

– Continuously involve Operations Staff– Try to “break” the design with Operating

Scenarios analysis Found nothing than time and money can’t fix!

bay area rapid transit gets global signaling presentation to “cbtc and beyond”: fifth...

Documents

bay area rapid transit

kwh slide

time slide

location slide

complete slide

bay fair phase

radio network slide

relay interlocking slide