KERNEX MICROSYSTEMS
A Presentation on
Train Collision Avoidance System (TCAS)
Exploring Depths of Knowledge
TCAS Project
• TCAS Development project was awarded to 3
Companies, as below:
 Package A- 140 KM awarded to Medha
 Package B- 70 KM awarded to Kernex
 Package C- 40 Km awarded to HBL
Exploring Depths of Knowledge
TCAS Project - location map
Exploring Depths of Knowledge
Package B (Kernex Scope) - location map
Exploring Depths of Knowledge
Main Objectives of TCAS
• Safety
 Prevention of SPAD
 Control of Speed at PSR/TSR
 Facility of SOS
 Prevention of Collision during NI Working
• Operational
 Simple Operation by Loco Pilot
 Continuous Update to ensure no Loss of Line Capacity
• Limited Trackside Equipment
Exploring Depths of Knowledge
Major Sub-Units of TCAS
• Station Units located in stations
• Loco Units located in locomotives
• IBS/LC Units located in block sections
• Centralized monitoring system
• Test benches at Loco Sheds
Exploring Depths of Knowledge
TCAS Block Diagram
Exploring Depths of Knowledge
TCAS
Architecture & Components
Exploring Depths of Knowledge
Typical Deployment Plan
Station TCAS
(GPS)
Station TCAS
Loco 1
RFID
Loco 2
Loco 3
Exploring Depths of Knowledge
Loco TCAS - Schematic
Exploring Depths of Knowledge
Loco TCAS major Sub-systems
• Dual Microprocessor based control system, along with dual
redundant radio modems, RF Tag Readers and GPS
Receivers
• Interface to the existing speedometer
• Event Logging sub-system along with blue-tooth data
uploading/down loading facility and redundant GSM I/F.
• Two Loco pilot Operation cum indication panel (LPOCIP) –
for Loco pilot and Asst. Loco pilot
• Braking interface unit (BIU)
• Dual Isolated Power Supply unit
Exploring Depths of Knowledge
Loco TCAS Architecture
Exploring Depths of Knowledge
Loco TCAS – Architectural Features
• Two redundant Microcontrollers (MIE 1 & MIE 2) working in “2
out of 2” mode to achieve high level of safety.
• All modules are connected through redundant CANBUS.
• Two redundant Microcontrollers (MIE 3 & MIE 4) as
communication processors.
• Two redundant Microcontrollers for peripheral interface.
• Separate Event logger for major events logging and storing for
90 days.
• Two UHF full-duplex Radio Communication Equipment with
hot standby and associated antennae:
 Frequency for Transmission by Loco : 441.8 MHz
 Frequency for Reception by Loco : 466.8 MHz
 Transmission by Loco for emergency (SOS) Communication
: 466.8MHz
Exploring Depths of Knowledge
Loco TCAS – Architectural Features ( Contd..)
• Dual Redundant GPS units are interfaced with Loco TCAS to get
synchronization for TDMA as well as to act as standby when
speedometer fails.
• Radio Antennae & GPS receiver antennae are permanently fixed
on the rooftop of the locomotive and connected to the Loco Unit
through RF cables.
• Dual Redundant RF-ID readers for finding Track Identification
Number (TIN) and Absolute location.
• Dual Redundant GSM/GPRS modems for health check and
transfer of failures to CMS.
• Bluetooth device for data up-loading and down loading.
• USB port for Event down loading.
• Loco Unit interfaced externally with Braking Interface Unit (BIU).
• Multi level Braking system, with the help of a proportional valve.
Exploring Depths of Knowledge
Loco Pilot Operation cum Indication Panel
•
Two LP-OCIPs (Operation cum Indication Panel) provided for
Loco pilot and Asst. pilot interaction with TCAS.
•
Functions performed:
1.
2.
3.
4.
5.
6.
7.
Speed indication in analog and digital forms
Display of immediate signal aspect
Target distance and movement authority in meters
Generation of SOS
Selection of Leading/ Non leading of loco
Light engine/ Formation selection
Display of system health
Exploring Depths of Knowledge
Loco Pilot Operation cum Indication Panel
Exploring Depths of Knowledge
Breaking Interface Unit (BIU )
• Based on Proportionate Valve – Brake pipe pressure will be
proportional to the input voltage
• Separate Light engine brake
• Separate Dedicated valve for emergency brake
• Does not interfere with the brake action of the Loco Pilot
• No continuous leakage of air after achieving the required
pressure.
Exploring Depths of Knowledge
RF Tag placement in Station
To be provided by Ajaiah
Exploring Depths of Knowledge
Station TCAS major Sub-systems
• Dual Microprocessor based control system, along with dual
redundant radio modems and GPS Receivers
• Event Logging System along with blue-tooth data uploading
/down loading facility and redundant GSM Interface and OFC
Interface.
• Station Master operation cum indication panel
• Station yard layout and status panel (21”)
• Dual Redundant Power Supply unit
• Battery and Battery charger
• 30 meter Tower for radio modem.
Exploring Depths of Knowledge
Station TCAS Architecture
Exploring Depths of Knowledge
Station TCAS Architectural Features
• Two Microcontrollers (MIE 1 & MIE 2) working in “2 out of 2”
mode to achieve safety of desired functionality.
• All modules are connected through redundant CANBUS.
• Two redundant Microcontroller (MIE 3 & MIE 4) working on
for radio communication and display.
• Event logger for major event logging and storage for 30 days
• Two UHF full-duplex Radio Communication Equipment with
hot standby and associated antennae
 Frequency of Transmission by Station : 466.8 MHz
 Frequency of Reception by Station: 441.8 MHz
• Two GPS units are interfaced with Station TCAS
• Radio Antennae & GPS receiver antennae are permanently
fixed on the preinstalled 30 mtr towers.
• Two GSM/GPRS modems for transfer of failures to CMS.
Exploring Depths of Knowledge
Station TCAS Architectural Features ( Contd..)
•
Station-OCIP (Operation cum Indication Panel) provided for
station master.
•
Existing fail safe signal, point status relay interface contact
input reading.
•
21’’ LCD monitor for yard display.
•
Bluetooth device for data Transfer.
•
Battery with battery charger cum power supply to provide
up to 24 hrs.
Exploring Depths of Knowledge
IBS/LC TCAS
• Intermittent block Station/ Level crossing gate TCAS is similar
to Station TCAS Unit, but with less no. of Inputs / outputs.
• No user interface
• Acts like a base station
Exploring Depths of Knowledge
Centralized Management System
GSM
Network
Loco 1
Loco 2
Railnet
Web
Reports
Central
Management
System
Loco 3
Web
Reports
LAN Network
Station A
Station B
Station C
Station N
Exploring Depths of Knowledge
Station/IBS/LC TCAS - Schematic
Exploring Depths of Knowledge
Trackside RFID Tags
• RFID Tags Provided at
 Start/End of TCAS Territory
 One Kilometer on Straight Track
 At Turnouts to detect diversions and Infringements
 Block Entry – foot of Last Stop Signal
 Station Entry – at the end of the Block Overlap at the
Station
 Foot of Signal
• Each Location with Pair of Tags for Redundancy
• Rigid Fixture with Clamps on Sleepers
Exploring Depths of Knowledge
TCAS
System Functions
Exploring Depths of Knowledge
ATP Functions
•In-Cab Signaling
•Detection and Prevention of SPAD
•Display of Distance of Signal and Movement
Authority
•Loop Line Speed Control
•Speed Control at PSR/TSR
Exploring Depths of Knowledge
Collision Prevention Scenarios
• Prevention of Head-On Collision
• Prevention of Rear-End Collision
• Prevention of Collision due to Unusual Stoppage in
Block Section
• Detection of Train Parting with External Input
• Manual SOS Generation Feature in Station TCAS
• Manual SOS Generation Feature in Loco TCAS
• Detection of Roll back
Exploring Depths of Knowledge
Supporting Functions
• Full Duplex Radio Communication
• Location with RFID and Existing Tachometer
• Automatic and Manual Brake Test
• No Database in Locomotive TCAS Unit
• Automatic Train Length Measurement Feature
• Station to Station Communication for Additional
Layer Block Protection
Exploring Depths of Knowledge
Modes of Operations
• Normal Mode
• Controlled Mode (when any vital system fails)
• Restricted Mode (15 Kmph operation)
• Staff Responsible mode (Manual mode)
• Coupled / banking operation
• Trip and Post Trip Modes
• On-Sight Mode
• Reverse Mode (to move in reverse direction)
• Shunting mode
Exploring Depths of Knowledge
Features of TCAS
• Full Duplex Radio Communication
• Location determination with RFID and existing Tachometer
• Automatic and Manual Brake Test
• No Database in Locomotive TCAS Unit ; hence operation,
handling of yard layout changes will be easy.
• Automatic Train Length Measurement Feature
• Station to Station Communication for Block Protection (as
additional layer)
• Time synchronization of complete network through GPS
Exploring Depths of Knowledge
Features of TCAS ( Contd..)
•
•
•
•
•
•
•
•
Handling of New Train Formation
RFID based Track Id & Location Determination
Multi Level Braking Interface
Provision of Controlled Mode (Manual mode) Operation
TDMA based Communication protocol
Startup/Online Diagnostics
Event Logging
Central Monitoring through GSM / GPRS network for
maintenance
• Data up-loading & down loading through ‘Bluetooth’.
Exploring Depths of Knowledge
Environmental Specifications
•
•
•
•
•
•
Operating Temperature: -10 to +70 deg. C
Relative Humidity
: 95% (non-condensing)
Vibration : 3 g for Loco; 2 g for Station & LC
Mechanical Shock : 20 g peak for 11 msec. (non-operating)
Bump : 40 g peak in packed conditions
MTBF (Planned)
 - Loco unit: 20,000 hrs
 - Station Unit: 60,000 hrs
Exploring Depths of Knowledge
Present Status
• Installed Station TCAS in Nawandgi and Kurukunta stations
• Installed Loco TCAS in one electric and one diesel loco
• KMIL participated in several field trials to study / verify
• Radio communication
• RFID readers and tags
• Inter-operability with other vendors equipment between
stations Tandur, Mantatti, Nawandgi and Kurukunta.
• Various control logics including SPAD
• Prototype testing completed. (Same was used for site trials
since Jan 14.)
• Independent Safety assessor (ISA) clearance for Hardware
design completed.
Exploring Depths of Knowledge
Present Status ( Contd..)
• System documents under review by ISA.
• Soil test for Tower erection completed.
• Approval for Tower locations in stations and LCs from SCR
obtained.
• Tower design with CPRI approval completed.
• Relay room wiring in Station- approval from SCR obtained.
• Unit level manufacturing in progress.
• Software documents under review by ISA.
• Software Functional logics developed and tested during site
trials.
Exploring Depths of Knowledge
TCAS
Scenarios
Exploring Depths of Knowledge
Detection & Prevention of SPAD
• Approaching Signal Aspect is Transmitted by Station TCAS to
Loco TCAS
• Loco TCAS Displays Signal Aspect on LP-OCIP
• In case Driver fails to apply brakes to reduce the speed/stop
the train, TCAS Applies brakes to stop the train.
• On Change of Signal Aspect to green, brakes will be released
Exploring Depths of Knowledge
In Cab Signaling
• Station TCAS gets inputs from Signaling and transmits the
same to the approaching Loco TCAS
• The Signal Aspect of the next approaching signal is displayed
on the LP-OCIP
• Movement authority is also displayed along with the signal
aspect on the LP-OCIP
• On Crossing the Signal, Next Signal Aspect and Movement
authority is automatically updated on the LP-OCIP
Exploring Depths of Knowledge
Display of Signal & Movement Authority
Exploring Depths of Knowledge
Loop Line Speed Control
• Station TCAS gets inputs from Signaling and transmits the
route Information to the approaching Loco TCAS
• In case the route is set to Loop Line and the Loco Pilot does
not apply brakes to achieve speed limit, Loco TCAS applies
brakes to regulate to the Loop Line speed Limit
• If Loco Pilot applies brakes, then Loco TCAS will not apply
brakes as speed is monitored dynamically
Exploring Depths of Knowledge
Prevention of Head-On Collision
• Two trains approach each other in Block section on the same
Track is sensed.
• Station TCAS Transmits the HOC Condition to both Locos
• Both Locos individually deduce HOC Condition based on
Emergency Broadcast
• Brakes are applied to both the Locos and brought to a stop
Exploring Depths of Knowledge
Prevention of Rear-End Collision
• Two trains approach each other in Block section on the same
Track is sensed.
• Station TCAS Transmits the REC Condition to both Locos
• Both Locos individually deduce REC Condition based on
Emergency Broadcast
• Brakes are applied to the Rear Loco and brought to a stop
Exploring Depths of Knowledge
Unusual Stoppage in Block Section
• One Train Stopped in Block Section either due to Derailment
or for any other Reason is sensed by Station TCAS
• Station TCAS Transmits the Unusual Condition to the other
Loco entering the Block Section
• Unusual Stoppage Emergency Broadcast also is sensed by the
approaching Loco
• Brakes are applied to the Approaching Loco and regulates to
15 Km/h
• In case there is no obstruction, Loco Pilot can increase the
speed after crossing the stopped Train
Exploring Depths of Knowledge
Manual SOS from Station
• There is a provision on SM OCIP for generating emergency
condition
• SM can Press the Manual SOS buttons
• All trains within the range of 3000m applies EB and stops
• Loco Pilots of the trains can press the Manual Override and
pilot the train at 15 Km/h
• On Cancellation of Manual SOS in the Source Loco, Speed
restriction is removed
Exploring Depths of Knowledge
Manual SOS from Loco
• There is a provision on LP OCIP for generating emergency
condition
• Loco Pilot can Press the Manual SOS buttons
• All trains within the range of 3000m applies EB and stops
• Loco Pilots of other the trains can press the Manual Override
and pilot the train at 15 Km/h
• On Cancellation of Manual SOS in the Source Loco, Speed
restriction is removed
Exploring Depths of Knowledge
Prevention of Collision due to Train Parting
• Using External Sensor for Train Parting, Loco TCAS detects
train parting condition
• Train Parting Message is sent to the Station TCAS as well as
transmitted in the Emergency Communication Slots
• Any Loco TCAS approaching the Parted Loco TCAS applies
brakes to regulate the speed to 15 km/h
• Driver can look out for infringement and can go at full speed
on crossing the Parted Train
Exploring Depths of Knowledge
Train Length Calculation
• Loco Unit Stores its position and speed in FIFO
• Station TCAS transmits the Start marker time stamp T1 to Loco
TCAS (in millisecond accuracy)
• Station TCAS transmits the End marker time stamp T2 to the
Loco TCAS (in millisecond accuracy)
• Based on the start and end time and the speed at which Loco
is traveling, Loco TCAS calculates the Train Length
Exploring Depths of Knowledge
Train Length Calculation
Event “End“
Event “Start“
Train Length
Event “Start“
Frame #n
Frame #n+1
t (Start)
Event “End“
Frame #n+2
Frame #n+3
Frame #n+4
t (END)
Exploring Depths of Knowledge
Auto Brake Test & Manual Brake Test
• When Loco reaches a speed of more than 50 Km/h and is
accelerating, Loco TCAS applies NB through Braking Interface
Unit (BIU)
• Speed is reduced by 20 Km/h
• Based on the time taken, Deceleration constant (DC) of the
train is calculated and stored for any future brake application.
• Default DC is taken as 0.2 m/s2
• Calculated DC is extrapolated for application of FSB and EB
• Manual Brake Test is applied in Loco sheds to test the
functioning of BIU
Exploring Depths of Knowledge
TCAS
Architectural Features and
Safety Certification
Exploring Depths of Knowledge
TCAS Architectural Features
• Two redundant Microprocessors/controllers (MIE 1 & MIE 2)
working in “2 out of 2” mode to achieve safety of desired
functionality
• Two redundant Microprocessor/controller (MIE 3 & MIE 4)
working on for radio communication and display.
• Two full-duplex Radio Modems with hot standby and
associated antennae
• One GPS unit is interfaced with Loco TCAS to get time
synchronization for TDMA as well as to act as standby when
speedometer fails.
• Radio Antennae & GPS receiver antennae are permanently
fixed on the rooftop of the locomotive and connected to the
Loco TCAS through RF cables.
Exploring Depths of Knowledge
TCAS Architectural Features
Contd..
• Interfaced with two RF-ID readers for finding Track ID.
• Interfaced with two GSM/GPRS modems for transfer of
failures to CMS.
• Interfaced with two LP-OCIP’s (Operation cum Indication
Panel) which are mounted on the Driver’s pedestal for easy
access and visibility to the Driver.
• Interfaced with Bluetooth device for data Transfer.
• Loco TCAS interfaced externally with Automatic Braking Unit
(ABU) for Normal Brake, Full Service Brake and Emergency
Brake
• Interfaced with 2 Field Input Modules (FIM) for Inputs.
• Interfaced with 2 Field output Modules (FOM) for outputs.
Exploring Depths of Knowledge
TCAS Architectural Features
Contd..
• Loco TCAS interfaced with existing odometer’s pulse
generator to compute location data.
• Loco TCAS also interfaces with Inter-Cock Switch (ICS) to
determine coupling / banking mode of train operations
• Logging of eventlogs by eventlog module, which can be
downloaded through Bluetooth.
• 1 Battery with battery charger to provide up to 30 min power
backup.
• 2 Hot Standby redundant power supply modules to provide
power supply to all the modules of Loco TCAS Unit
Exploring Depths of Knowledge
Safety Certification
• Independent Safety Assessor (ISA) done by ERTL, Kolkata
• Hardware Design is Verified to provide required Safety
• Software Design is Verified to provide required Safety
• System is Validated Independently to ensure proper
functionality
• Design and Safety Documents are Verified to meet required
Safety Level
• On completion of assessment, Certification is done
Exploring Depths of Knowledge
TCAS
Radio Communication
Exploring Depths of Knowledge
Radio Communication
• Full Duplex Communication
• Stationary Units Transmit on Frequency ‘F1’ and Receive on
‘F2’
• Locomotive Units Transmit on Frequency ‘F2’ and Receive on
‘F1’
• In Emergency Situations, Loco Units also transmit in ‘F1’ and
tune back to ‘F2’ for Listen.
• Uses Time Division Multiplexing (TDMA) for Communication
Exploring Depths of Knowledge
MR3
86
ME3
2704
Bits
M7
2
48
M7
6
304
48
496
MTP
3504
Bits
304
M7
1
496
M6 M6
2 3
MR4
8
1
ME4
304
M5 M5
3
4
304
496
M4
5
7
9
496
304
496
304
496
304
496
304
M4
4
496
M3
9
0
75
S9
304
3504
Bits
S
8
3504
Bits
304
96
304
3504
Bits
7
2
496
1094
Bits (
Repea
ter/En
d
M4
Cabin)
96
S7
96
S6
S
5
6
8
304
( Addl SOS/
Emergency
Tx)
M
5
6
6
304
496
Tx by Train
304
Tx by
Train
(f2)
48
304
96
304
96
M
1
96
1094 Bits
(
Repeater/
End
Cabin)
S
4
304
Tx by
Stationary
(f1)
48
304
96
304
96
S1
55 56
304
96
304
45 4
6
304
96
304
7
304
96
1 2 3
304
96
304
Timeslot
Position
Marker
96
Communication Time Frame
(f1)
Exploring Depths of Knowledge
TCAS
Position Determination
Exploring Depths of Knowledge
Position Determination
• Loco TCAS is fitted with two RF Readers.
• RF Tags are fitted on the sleeper
• On Crossing RF Tag, Loco TCAS gets Absolute Position
• From tachometer Speed, position is accumulated
• GPS is used as fall back, in case of tachometer failure
• Tag Crossed + distance traveled is Transmitted to Station TCAS
• Station TCAS Calculates position of Train based on Absolute
Position of Tag + Distance Traveled
Exploring Depths of Knowledge
THANK YOU
Kernex Microsystems (India) Limited
‘THRUSHNA’, PLOT NO 7, A.P.I.I.C LAYOUTS
HI-TECH CITY, MADHAPUR, HYDERABAD – 500081
Tel: +91-40-23113192-94, Fax: +91-40-23113191;
URL: www.kernex.in
Exploring Depths of Knowledge