ITCS

Incremental Train Control SystemOn Amtrak’s Michigan Line

WHAT IS ITCS?• ITCS is a vital wireless train control system

– Applied as an overlay to the existing signal system (CTC)

• ITCS Features– Positive stop enforcement at fixed signals– Enforcement of MAS/permanent speed restrictions– Enforcement of temporary speed restrictions– Advance start of highway crossing warning devices– Location determination system blends dual differential

GPS & the tachometer

Michigan Territory Overview

MP 216

MP 195-216ITCS Installed but not yet

operational

MP 195

MP 150

MP150 - 195

ITCS Territory Limits

ITCS in O

peratio

n

Niles

Kalamazoo

How ITCS Works in Michigan• The fixed signal system (CTC) is the foundation• ITCS servers, Train-to-Wayside Link (TWC),

communicate to wayside devices & route data to trains – VHLC vital processor with special software, MCP ATCS

Radio communications and GPS • ITCS Wayside Interface Units (WIU) monitor signals &

crossings– Standard VHLC equipment – MDS Spread Spectrum Radios send vital data between

WIUs and Train-to-Wayside (TWC) servers• ITCS Onboard Processor (OBC) – all onboard processing,

GPS & communications– Database is loaded prior to departure (departure test)– Database is verified en-route via TWC approaching every

server (5 -7 miles apart),

How ITCS Works in Michigan (cont’d)• Advance start of crossings

– As train approaches crossing it establishes communication with nearest server

– Server notifies crossing when to activate warning devices– Crossing notifies server via vital link that warning devices

will activate at prescribed time– Server allows train to continue at MAS– If train does not get notice that crossing is activated, train

speed must be reduced to default speed (normally 79 mph)

Dispatch Center

GPS differential correction, Temporary

Slow Orders and Wayside Status

Messages to Train

ITCS Server LocationWIU Location

GPS Satellites

ITCS Michigan Line Overview

Office to Wayside Link (OWL) for Temp. Slow orders

ITCS Michigan Line Overview

MDS Spread Spectrum Radio

(Talk to Wayside)

GPS Receivers

ITCS RBC/Server

MCP Radio

(Talk to Train)

MCP Radio Antenna

(Talk to Train)

GPS Antennas

Servers collect wayside data, and talk to the trains

ITCS Server housed in existing infrastructure or small add-on boxes

11 ITCS servers installed in Michigan

ITCS Server Hardware

ITCS Michigan Line Display

ITCS Display in the Cab

– LEDs - Mode, Overspeed, Penalty– Speed Limit, Actual Speed

– Target Window• Target Speed, Time to

Penalty• Distance to Target

– Target Type

– Information Window• Milepost• Loco Type, Train Type

Approaching a Stop Signal– Speed Limit

• 110 MPH– Current Speed

• 86 MPH– Stop Signal

• Target Speed = 0– Time To Penalty

• 25 seconds to BEGIN applying the brakes

– Distance to Target• 11060 feet to signal

– Home Signal• HOMESIG

– Train Location• MP 181.5

– Train Type• F40 Locomotive, Passenger

Train

Why ITCS on the Michigan Line?

• Chicago to Detroit identified as a potential high-speed corridor

• Michigan DOT wanted high-speed passenger service (110 MPH)

• FRA requires in-cab signaling/enforcement for speeds above 79 MPH

• Conventional cab signaling would have worked however:– Would not include permanent and temporary speed

enforcement– Would not include positive stop enforcement– Crossing approaches would have to be extended for higher

speeds

Why ITCS on the Michigan Line? (cont’d)

• ITCS was conceived to:– More cost-effectively implement cab signaling

• Enforces speeds associated with existing wayside signal aspects

– Pre-start grade crossings over the radio network• Also helps prevent short warning times because of loss

of shunt due to rusty rail– Deliver and enforce speed restrictions (permanent &

temporary)– Increase speeds to 110 mph without redesigning the signal

system

ITCS Background

• 1995 - FRA grant awarded to Michigan DOT, Harmon (now GETS) and Amtrak for PTC demonstration project

• Oct. 1996 – 100 MPH demo, signal 175 to signal 195

• March 2000 – In service (display only) without enforcement

• April 2001 – Enforcement @ 79 MPH

• Jan. 2002 – Revenue service @ 90 MPH

• Sept. 2005 Revenue service @ 95 MPH

Problems Encountered

• Problem #1: Excessive errors in synchronous WLAN caused too many train delays

• Solution: WLAN was changed out to new MDS asynchronous radios

• Result: Wayside communication errors greatly reduced; performance greatly improved

• Problem #2: Spotty TWC coverage causing too many miscommunications between servers and trains

• Solution: Redesign of TWC system– Obsolete MCP radios will be replaced– Coverage will be improved by going from 900 MHz

system to 220 MHz system– Radios will be networked for better connectivity

Problems Encountered (cont’d)

• Advantage of proposed network:– Any train can communicate with any server via the

network, a direct line-of-site connection is not required– RF holes can be eliminated w/o relocating servers or

modifying territory boundaries– Servers and TWC radios do not have to be co-located– New wayside and locomotive radios will be SNMP

enabled for better management and diagnostics• Must be completed before speeds are increased to 110 MPH• Target completion is by the end of 2007

Present Status

• V&V effort continues– WIUs are complete– VHLC servers are complete– Location processor complete– Host processor undergoing upgrade by GETS

• New hardware to be installed on locomotives June ’07• V&V completed by GETS Aug. ’07• Third party review of V&V completed by Oct. ’07

• Design and replacement of TWC network– Still in legal and procurement– Projected to be complete by end of 2007

• Projected revenue service date @ 110 MPH is early 2008

PRESENT STATUS

CP147 (147.1)

KAL (143.4)

BTL

DET

Amtrak Michigan Line

NS Michigan Line

NLS (191.9)

CHI

CP 213 (213.9)

NS Chicago Line

ITCS Revenue Service45 Miles Main Track 4 Controlled Sidings 95 MPH

8

Porter CP 482 (240.7)

(150.4) Signal 150

Signal 195 (195.6)

Signal 216 (216.1)

ITCS Installed 21 Miles Main Track 2 Controlled Sidings

ITCS Total 66 Miles Main Track 6 Controlled Sidings

RBC 1

RBC 2

RBC 3

RBC 1 TERITORRY RBC 2 TERITORRY RBC 3 TERITORRY

RF coverage required by a single RBC

RBC 1

RBC 2

RBC 3

RBC 1 TERITORRY RBC 2 TERITORRY RBC 3 TERITORRY

RF coverage can have path fades

ITCS mitigates occasional RF path fades

RBC 1

RBC 2

RBC 3

RBC 1 TERITORRY RBC 2 TERITORRY RBC 3 TERITORRY

Some RF path fades can cover wide areas

If the RF path fade is excessive, the system restricts traffic to a fail safe condition – in this case restricting entry into server 2 territory. RBC 1 is in coverage of the train. But it doesn’t have a data path to RBC 2

RBC 1

RBC 2

RBC 3

RBC 1 TERITORRY RBC 2 TERITORRY RBC 3 TERITORRY

Networked radio system

Wide Area Network

With the base radios connected to a network, any radio within coverage of the train can pass the packet to and from the addressed RBC. Radios cover a smaller area and provide some overlap

Coverage Overlap

RBC 1

RBC2

RBC 3

RBC 1 TERITORRY RBC 2 TERITORRY RBC 3 TERITORRY

Permanent RF path fades – buildings, trees, etc.

Wide Area Network

Sometimes coverage RF changes causing a large RF coverage gap – land fill in Michigan

Permanent fade

RBC 1

RBC 2

RBC3

RBC 1 TERITORRY RBC 2 TERITORRY RBC 3 TERITORRY

Wide Area Network

We can add a base station to fill in the coverage gaps

We can insert a radio into the network anywhere

RBC 1

RBC 2

RBC3

RBC 1 TERITORRY RBC 2 TERITORRY RBC 3 TERITORRY

Additional benefits of the networked system

Wide Area Network

Network Management System for all radios, routers, etc.

Simplified diagnostic interface for RBCs, etc.

WAN can be any IP based system, Fiber, Microwave, HDSL, etc.

WIUs can be connected via the WAN