Transcript IRSE
N KASHINATH
CSTE/P/S.RLY
TPWS PROJECT
Provided on Chennai Central/Chennai
Beach - Gummudipundi section of
Chennai division
Section length- 50 RKMs
Date of commencement- 24.02.05
Date of commissioning- 02.05.08
Total EMU rakes covered- 41 rakes
TPWS BENEFITS
Ensures safe movement of trains under its
supervision
Prevents over-running of the movement
authority (MA)
Automatically brings the speed of train
within permitted limits in case of over
speeding
Prevents train from entering danger zone
if the driver fails to control while
approaching a ‘RED’ signal.
TRACK-SIDE EQUIPMENT LAYOUT DIAGRAM
Note
JB-Balise Junction Box
LEU-Lineside Electronic Unit
Not to scale
Existing Signal
LEU
Cabinet
Existing
Signal
Location
Box
A
Infill Balise
CO
Data Cable
JB
e
e
JB
Fixed
Balise
e
Switchable
Balise
ON BOARD EQUIPMENT LAYOUT DIAGRAM
OBC-On Board Computer
BTM-Balise Transmission Module
DMI
On BoardCubicle
OBC
BTM
Wheel
Sensor
Brake
Valves
JB
JB
JB-Junction Box
Wheel
Sensor
Antenna
RE-TRAINING OF MOTORMEN
• After commissioning a second round of
training organised for improving their
confidence
• New motormen were also covered
• Operating instructions of TPWS to
motormen revised and made more
comprehensive
PERFORMANCE MONITORING
Ansaldo staff stationed at both ends of the
section
To ensure switching ON of TPWS
Monitoring condition of TPWS at
commencement and end of journey
Motormen recording en-route failures in the
EMU log book for onward transmission to
TPC.
FAILURE ANALYSIS
• On-board computer logs periodically
downloaded
• Logs analyzed using specially
developed sorting software
• Problem noticed on Track-side and Onboard system solved to the extent
possible
• Track-side system became fully stable
ON-BOARD PROBLEMS PENDING
RESOLUTION
On-board system sometimes not booting
System Failure (SF) sometimes while
booting
SDMI on the run sometimes going blank
Brake application due to speed bouncing
on SDMI
Brake application in the non-driving rear
motor coach
MITIGATING UNRESOLVED
PROBLEMS
• Experts called from Ansaldo France,
Australia, Italy and Hong Kong
• They carried out detailed observations
in field
• Error logs of OBC studied
• Error logs sent to their countries for
analysis by specialists
CAUSES IDENTIFIED
BTM-Antenna communication failure
Error in Train Interface Unit (TIU)
Error in Odometric (speed sensing)
system
Back EMF from Electro Pneumatic (EP)
brake relay and solenoid valve coils
Bugs in SDMI software and hardware inadequacies
Rear coach on-board system getting shut
down during run in Sleep Mode
BTM-ANTENNA COMMUNICATION
FAILURE
• Due to antenna impedance mismatch
• Standing Wave Ratio (SWR) found
more than the tolerance limit of 1.2 to
1.4
• Interference from EMI
CORRECTIVE ACTION
• Antenna protection cover modified
• BTM to Antenna Tx/Rx cables shielded
with copper braids firmly connected to
body
• PROFIBUS and CTODL cables between
OBC & BTM shielded with copper
braids
• BTM configuration files modified
TRAIN INTERFACE UNIT ERROR
• Communication problem between
CBOP and MTORE cards in OBC
• Noise/Ripples in the 110V DC supply to
OBC from the EMU battery
• Causing intermittent on-board system
failure
CORRECTIVE ACTION
Cables between CBOP and MTORE
cards changed to screened twisted pair
cables
Power filter provided at the input of
110V DC to OBC
All OBC rack wiring changed as per
modification plan sent by Ansaldo,
France
ODOMETRIC SYSTEM ERROR
• Interference from EMI
• TPWS traction control relay generating
wide spectrum of noise
• High resistance between EMU body
and the bogie
CORRECTIVE ACTION
Cable between OBC and Speed sensor
shielded with copper braids firmly
connected to body
TPWS traction control relay shifted
outside OBC cubicle
EMU body to bogie firm connection
provided
BACK EMF FROM EB VALVE AND EP
RELAY COILS
• EB and SB relays found affected by
EMI
• Back EMF of EB solenoid valve coil
and EP brake relay coils found high
• Problem became more acute during
braking
CORRECTIVE ACTION
• EB solenoid valve coils terminated with
180/200V MOVRs
• EB & SB relay bodies firmly connected
to EMU coach body
• Surge suppressor provided at the EP
brake coil
BLANKING OF SDMI ON RUN
Basic hardware and software
inadequacies
Residual bugs in SDMI software
Interference from EMI
Ripples in 110V DC input power supply
CORRECTIVE ACTION
SDMI software upgraded to next higher version
v1.6.4
OBC-SDMI communication cable connector
cover changed from plastic to metallic
OBC-SDMI and SDMI power supply cables
shielded with copper braids firmly connected
to coach body
Power filter provided at the SDMI-110V DC
input point
REAR COACH ON-BOARD GETTING
SHUT DOWN ON RUN
• Due to errors in various subsystems
the on-board gets shut down.
• On-board shutting down activates EB
command
CORRECTIVE ACTION
• Brake interface circuit modified to
bypass EB command in Sleep Mode.
• Prevent the On-Board in sleep mode
from getting shut down by the
modifications discussed earlier.
PLAN OF ACTION FOR
MODIFICATIONS
• One by one motor coach to be taken
OFF service & handed over to Ansaldo
• Initially 4 coaches were got modified
• Their performance closely monitored
for 4 weeks
• Found substantial improvement in
performance of these 4 coaches
PLAN OF ACTION FOR
MODIFICATIONS…contd
Balance coaches also decided to be
modified
Ansaldo initially took 3-4 days for
modifying a coach
Ansaldo asked to reduce it to 2 days by
working in two shifts
17 coaches modified till date
EXPECTATIONS
Most of the coaches are expected to be
modified by 31.05.2010
Improved performance levels expected to
meet the operational requirements
Could lead to acceptance of TPWS for
safe running of EMUs
Top management requested to be patient
for the results