Mobile LiDAR to Support Positive Train Control

This article was originally written in 2011, but is being re-posted based on recent events…

DTS/Earth Eye just completed a positive train control (PTC) project for a national train company who was evaluating the differences between Airborne LiDAR and Mobile LiDAR to support the collection of PTC data.  They are currently collecting airborne data for approximately 15,000 linear miles of rail.  In certain areas, the airborne data does not provide enough fidelity to accurately map the rails or the asset infrastructure that support the railroad operations.

From Wikipedia – “The main concept in PTC (as defined for North American Class I freight railroads) is that the train receives information about its location and where it is allowed to safely travel, also known as movement authorities. Equipment on board the train then enforces this, preventing unsafe movement. PTC systems will work in either dark territory or signaled territory and often use GPS navigation to track train movements. The Federal Railroad Administration has listed among its goals, “To deploy the Nationwide Differential Global Positioning System (NDGPS) as a nationwide, uniform, and continuous positioning system, suitable for train control.”

The project involved the collection of Mobile LiDAR using the Riegl VMX-250 as well as forward-facing video to support PTC Asset Extraction.  The system was mounted on a Hi-Rail vehicle and track access was coordinated through the master scheduler with the Railroad company.  Once we had access to the tracks, we had one shot to make sure the data was collected accurately and we had complete coverage.  All data was processed on-site to verify coverage and we had a preliminary solution by the end of the day that was checked against control to verify absolute accuracies.  We collected the 10-mile section of rail in about 2 hours and this timing included a couple of track dismounts required to let some freight trains move on through.

IMAG0166IMAG0168

The following graphics illustrate the point cloud coverage colored by elevation (left) and Intensity (right).

imageimage

imageimage

Mapping the rails in 3D was accomplished by developing a software routine designed to track the top of the rail and minimize any “jumping” that can occur in the noise of the LiDAR data.  Basically, a linear smoothing algorithm is applied to the rail breakline and once it is digitized the algorithm fits it to the top of the rail.  The following graphic illustrates how this is accomplished – the white cross-hairs on the top of the rail correspond to the breakline location in 3D.

image

So, back to the discussion about Airborne PTC vs Mobile PTC data.  Here is a signal tower collected by Airborne LiDAR.  The level of detail needed to map and code the Asset feature is lacking, making it difficult to collect PTC information efficiently without supplemental information.

image

The next graphic shows the detail of the same Asset feature from the mobile LiDAR data.  It is much easier to identify the Asset feature and Type from the point cloud.  In addition to placing locations for the Asset feature, we also provided some attribute information that was augmented by the Right-of-Way camera imagery.  By utilizing this data fusion technique, we can provide the rail company with an accurate and comprehensive PTC database.

image

This graphic shows how the assets are placed in 3D, preserving the geospatial nature of the data in 3D which is helpful when determining the hierarchy of Assets that share the same structure.

image

One last cool shot of a station with all of the furniture, structures, etc that make it up – pretty cool!

image

Strategic Asset Management vs. Work Management–What’s the Difference?

We do business with a lot clients these days who are looking for an “Enterprise Asset Management” system .  They use this term during the procurement process, but in a lot of cases their requirements are centered on Work Management and barely scratch the surface of Asset Management.  This is easy to do since most of an organization’s daily activities are focused solely on today’s maintenance of their Asset Infrastructure, but there is very little focus on how they will manage and maintain assets into the future.  Our clients are always answering questions related to the fiscal activities centered on asset performance.  The questions from management are centered around:

  • How much are we spending on maintenance?
  • How long does it take us to respond to and fix an issue?
  • Are we meeting Federally mandated requirements?
  • Anything else relating to money…

The IAM defines asset management as the “coordinated activity of an organization to realize value from assets”.  This involves the “balancing of costs, opportunities and risks against the desired performance of assets, to achieve the organizational objectives.”  An additional objective is to “minimize the whole-life cost of assets but there may be other critical factors such as risk or business continuity to be considered objectively in this decision making.”  All of these factors can be combined together to make informed decisions regarding how assets are managed and maintained throughout their life-cycle.  These decisions involve monetary expenditures, but they also involve strategic thinking centered on the “How” and “Why” to fix an asset as well as “When” and “Which” portions of this process.  This is the “Strategic” piece of an Asset Management system.

image

Work Management is one small component of Asset Management.  It is typically focused on the day-to-day operations and expenditures related to operating and maintaining asset infrastructure.  The Work done against an asset can track cost information, but can also be used to build a strategy around the operations and maintenance related to that asset.  This strategy focuses on the “How” and “Why”.  It answers what “Activity” should be completed for an asset (Install, Maintain, Repair, Replace) and “Why” (It’s old, looks bad, is dangerous, could cause injury, get us sued) this should happen.  Next, it answers “When” (now, next year, or never) an asset should be maintained as well as “Which” (most critical, most likely to fail, the Mayor’s sewer line) assets should get priority.  All of these factors are important and ALL of them should be utilized when making a Strategic Asset Management decision.  Be reminded that Work Management is only one component of this decision-making criteria which is applied to an overall Strategic Asset Management plan.