Automatic 3D monitoring and the use of network adjustment on the - - PowerPoint PPT Presentation

Automatic 3D monitoring and the use of network adjustment on the railway

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Contents

• Monitoring
• Automatic 3D Monitoring
• 3D Monitoring on the Railway
• Data Interpretation/Calculation
• 3D Monitoring Evolution
• Network Adjustment in Remote Systems
• Case Study: RMS
• Summary

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Monitoring

• 1. Define the purpose:

Inform, Maintain, Control

• 2. Select the monitoring method:

Amount, speed and accuracy of data required etc…

• 3. Define and agree the reporting and actions:

What happens following the data.

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Stage 1 ‐ Define the Purpose

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Inform

• Obtain knowledge of asset behavior
• Enable evaluation of severity
• Data for design of remediation

Maintain

• Confirmation of status – notification of change
• Contingency – Interim period to repairs

Control

• Measurement towards limit of movement/alarm
• Observation during temporary works
• Short term watch period due to sudden instability

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Factors Influencing Decision to Monitor

• New or Dormant Fault
• Asset Criticality
• Severity of Fault
• Level of Consequence
• Visibility
• Reinforcing Knowledge
• History
• Culpability
• Politics
• Cost

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Would you monitor this?

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Stage 2 – Select Monitoring Method

• Reliability (Repeatability & Accuracy)
• Availability
• Cost
• Access
• Minimal install time
• Robustness/Climactic conditions
• Simplicity of use
• Operate alongside site activity
• Security
• Direct Measurement
• Ergonomic contingent design
• Low power consumption
• Communications

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Practical Considerations ‐ Safety

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Stage 3 – Define and Agree Reporting and Actions

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• Analyse
• Compare
• Alert & Alarm
• Report
• Present
• Repeat
• Archive
• Record
• Transmit
• Store
• Back up
• Confirm
• Convert
• Validate

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Automatic 3D Monitoring

• In terms of Purpose of monitoring (stage 1) can offer

information to suit all types

• Measurement of a single point in 3 planes of direction to +/‐

1mm

• Absolute and global movement
• Monitor a wide range of infrastructures/furniture with

relative ease

• Mainly unobtrusive to install and can operate in hard to

access area’s

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Automatic Systems

Historically remote system were borne out of areas that were difficult to manually monitor. E.g. Tunnels, culverts, cuttings Their potential to be more cost effective than manually monitoring areas was by product as well as all the other benefits of remove monitoring. Crossrail C701 was what really brought ATS monitoring to the fore and brought its use to a much wider audience. This and other Crossrail contracts propelled the logistical use and subsequent development of 1 second instruments.

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Standard ATS Set Up

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Controls ATS’s Monitoring Points

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3D Monitoring on the Railway

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• Slope Surface Monitoring
• Retaining Walls
• Bridge Structures
• Buildings
• Platforms
• Tunnel Clearance
• Track

Track Monitoring

• Cant & Twist
• Lateral Slew
• Gauging
• Settlement & Heave

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Data Interpretations/Calculations

• Rotation
• Longitudinal profiles
• Convergence Vectors
• Relative Movement
• Absolute Movement
• Cant, Twist & Gauging
• Daily Averaging

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Alarm Management

• Email
• Texts
• Alarm Logs
• Event Logs

Alarm management tools

• Within a range or shot again
• Mode
• 3 Tap Rule
• Daily Average Alarms

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Evolution of Remote 3D Monitoring

• Robustness: Higher IP ratings
• Speed of Readings
• Camera’s on Instruments
• Power consumption to be run
• Communication improvements

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Introduction of Network Adjustment into remote systems

Allows you to control and manage the position of your monitoring points by modelling through least squares adjustment. The adjustment allows you to create a network for your survey site and correct the data once the network is solved. It reviews your whole site as one and then creates a best fit based on this. Widely used in manual systems where there is poor control set ups. Started to be used in more remote systems and was a key component to many Crossrail sites due to the environment.

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Network Adjustment

Key items in a good network adjustment is good common points and known stable points. Network Adjustment packages can now process the data every 2 hours and can therefore replace the need to show resected data and as live data. Especially important in tunnel areas, bends, cuttings etc. Anywhere where line of sight out of the zone of influence is

• restricted. E.g. Cuttings, Tunnels

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Case Study: Royal Mint Street

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• 7No Automatic Total Stations
• 750 Mini Prisms
• Track Monitoring
• Retaining Walls
• Tunnels
• Crack Monitoring

Case Study: Royal Mint Street

• Originally set up as standard resecting system where each

instrument uses points outside of the ZoI in order to locate itself

• Change in building design meant a change in monitoring

method.

• Common Points file run between all 7no instruments to find
• ut which points can link the network
• Allowed us to create a network, process and adjust the data
• n a 2 hourly data (Which was within the defined

specification for the scheme)

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Summary

Understanding the system and its restrictions is key to getting the most out of it:

• Optical System
• Outside influences
• Poor Mounting positions
• Poor initial design due to outside constraints
• Anomalies
• Instrument Failure

Automated 3D monitoring is improving is robustness, reliability and communications to create a more practical system as well as a technical one. Network Adjustment is now a viable option when certain environments are encountered and areas need to be monitored.

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Where to next?

• Remote Scanning solutions from a Total Station
• Faster Database computations
• Wider and improved use of adjustment packages

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Questions?

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