Railway Bridge Health Monitoring System using wireless mesh networks and TSMP.

1. Railway Bridge Health
Monitoring System
A Refined Approach

2. Design Consideration
 Easy to Deploy
 Low Maintenance
 Long-Term

3. Application Requirements
30-­‐125m
3-­‐axis
accelerometers

4. Application Requirements
 What to measure? Acceleration in 3-
axis of motion
 Frequency components of interest
0.25-20Hz
 How long to measure?
 40 sec of total vibration during and after
train’s passage
 Time Synchronization
 Need accuracy of 5ms

5. Existing Techniques
 Visual inspection
 Mostly wired solutions
 Equipment is bulky and very expensive
 Large setup time (few days) for short-term
monitoring
 Few wireless solutions
 Proprietary non scalable solutions
 Wisden (USC)
 Golden-gate bridge (UCB)
 BriMon

6. Existing Approaches
 GSM Data Transmission (Data)
 Solar Panels (Power)
 GPS (Time Synchronization)
 Star Topology (head node)
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7. Star Networks
 Central base-station communicates directly to
sensor nodes - Generally mains powered.
 All routes are ‘linear’ where each node only has
one possible communication path.
 The failure of an individual link means that
information is lost.
 Generally requires site surveys and link-level
configuration.
 Each node must be positioned correctly and each
point-to-point link tuned for maximum reliability.

8. Mesh Networks
 Full-mesh networks provide fully redundant
routing to the edge of the network.
 Increased reliability, easy network installation and
long-term predictability.
 Every device has the same routing capabilities.
 Lower power consumption.
 True self-organising and self-healing without
constraints imposed by device type and
architecture.
 Easy network expansion.

9. Wireless Mesh Network (TSMP)
 Time Synchronized Mesh Protocol
(TSMP)
 >99.9% reliability
 Lowest power per delivered packet

10. How it Works: CSMA

11. How it Works: TSMP

12. Frequency Hopping: CSMA

13. Frequency Hopping: TSMP

14. Scalability: CSMA

15. Scalability: TSMP

16. Installation (Less work, Less wire,
Less conduit…)
 No Site Survey
 Installed Like a Wired Device
 Commissioned Like a Wired Device
 Operates Like a Wired Device

17. Maintenance
 redictive and timely
P
indication of failure
trends
Send Maintenance
 elivers accurate and
D ONCE to repair …
actionable data more
effectively than
monthly snapshots
… Not 20 TIMES
to CHECK

18. 25
Radio Performance
20 X With software:
cc2420
10 years  D cell
IRX (mA)
15
X
10 cc1000
With software:
5
10 years  coin cell
Molnar 04 (0.4mA) Cook 06 (300 µW)
X X X
Otis 05 (0.4mA) 100k 300k Bit rate (bps)
200k

19. Train
Detec+on
Data
Uploading
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20. Questions?
 Jose V. Ortega
 817-727-4530
 jvortega@sekiur.com