Award-winning Gyrobotic Survey System Takes Underground Mapping to a New Level

The Gyrobotic system mounted on a crawler unit.For more than 30 years, Infotec has pioneered the technology of inertial gyroscopic mapping as a means of plotting the route and datum level of underground pipes, culverts, tunnels and similar buried utility infrastructure.

Over the last decade, the company has developed this solution into the United Kingdom’s only commercial gyroscopic surveying system, known as ‘PipeTrack 3D.’ In the process, Infotec has also built a reputation for delivering results in problematic situations where man-entry options are unavailable or where the risks are too great to consider any alternative methods. Surveys can be undertaken at any depth and inside any pipe material with the survey capability being unaffected by external factors such as temperature variations, the earth’s magnetic field or electromagnetic interference generated by adjacent utility services.

Survey capabilities have advanced considerably over the past 18 months, particularly with the addition of autonomous robotic (ROV) and submersible (SUV) mobilization capabilities that have greatly extended the types of infrastructure and the range of survey that can now be completed. In addition, Infotec’s mobilization platforms allow the simultaneous deployment of a wide range of additional surveying technologies such as LiDAR internal laser scanning to build a Cloud-based data model or digital replica, which provides a definitive replica of the surveyed structure. The gyroscopic capabilities of the system uniquely position each and every point of the survey, with point clouds typically recording up to a million individual points of data every second.

Various components of the Gyrobotic system.In situations where visibility in impaired, such as beneath dirty water or inside fuel pipelines, visual measurement is replaced and acoustic or sonar measurement systems are used. The technology has already been used to perform surveys inside water-filled culverts with SUVs being used to overcome substantially silted conditions, limitations that prevented any other means of survey.

Furthermore, additional sensors may be added to the system to provide enhanced survey capabilities. For example, filtered acoustic sensors may be used to detect leak noise. Water entering or leaving a pipe under pressure via a defective joint, crack or fracture, emits a recordable noise. By combing these recordings with the image data and the advanced positional information, these new techniques provide the most advanced leak detection capabilities. Leak noise may also be detected on adjacent pipework, with the noise of an adjacent leaking water main identified whilst surveying a sewer or gas main laying in close proximity to the surveyed structure. Temperature and pressure sensors can be used to monitor minute changes with the precise XYZ coordinates associated to each and every recordable feature or defect.

A culvert survey output after using Gyrobotic and LiDar systems.The combination of Gyroscopic Mapping, advanced robotic mobilization platforms and in-pipe or in-tunnel LiDAR imaging systems has given birth to an entirely new type of survey, the ‘PipeTrack Gyrobotic Survey.’ According to Infotec, this delivers what is without question, the most advanced underground mapping capability currently available anywhere in the world. However, the ability to generate and build an accurate digital replica of underground infrastructure provides only a small part of the benefits that will be obtained by using this technology. The real benefits are gained when any subsequent survey is undertaken. The original cloud data acts as a benchmark or template which can be used to compare subsequent change at any point in the surveyed system. Specifically, tailored change recognition software, overlays comparable data sets enabling automatic flagging of even minute changes. Changes may include distortion, deformation, delamination or crack progression. Precise measurement will remove any requirement for third party interpretation and eliminate any risk of human error in the survey analysis.

Survey output from a LiDar survey.So what are the benefits and where can this technology be used? The obvious advantages relate to asset owners and the opportunity to use these surveys to monitor change, to enable more effective preventative maintenance and to avoid, in the worse cases, potential failure. This in turn facilitates the use of the technology for pre- and post-condition surveying and monitoring during adjacent works or operations such as piling or excavation. However, the ability to accurately position and define the extent and profile of any structure also allows work to take place closer to adjacent structures than would otherwise have been possible. This therefore benefits others looking to perform work in close proximity to critical underground infrastructure or buried utilities. The granting of Build-Over Consent or the chance to reduce restrictive easements which might blight or limit site development will be seen by many as an advantage, particularly as the viability of the structure can be monitored continuously, avoiding accidental damage during periods of invasive work.

The benefits also facilitate more effective use of Trenchless (No-Dig) Technology. The chance to use techniques such as Horizontal Directional Drilling or similar moling or tunneling systems, allows remote works to pass under, over or even to connect new lateral branches to existing infrastructure, avoiding unnecessary excavation, minimizing surface level disruption.

– Survey output from a LiDar survey.Step-by-step the data obtained using this latest survey technology adds value to the records for underground assets with the data gathered providing the most comprehensive ‘as-built’ survey possible, with structures both old and new being surveyed and a time stamped record of condition being captured as a reference for future use and comparison.

Opportunities for the use of the data also extend to enhanced design capabilities. For the first time, the data will provide accurate ‘as-built’ information such as localized changes in gradient and unrecorded changes in shape or size as a result of repair or modification. This facilitates improvements in tasks such as hydraulic modelling and enables more effective improvements for projects such as flood prevention or flood alleviation studies.

On a larger scale, the survey capabilities extend to the transportation infrastructure such as road or rail tunnels. Gyrobotic Surveys are already being considered as a fast and effective means of recording change in situations where limited access opportunity is afforded for inspection and assessment. Where failure could result in a risk to life as a result of the derailment of a fast moving train or vehicle, the need to identify change which can be assessed to predict the potential risk of failure is even greater. However, the capabilities devised for one sector ultimately benefits others, to a greater or lesser extent. Gyrobotic Surveying although in its infancy is in fact an amalgamation of several mature technologies. The opportunities are therefore, according to Infotec, unlimited, with new challenges to be met with further developments that will undoubtedly follow.

David Pitt, managing director of Infotec also commented: “The idea of the Gyrobotic Survey is something we have been developing for some time now. It now has the capacity to meet survey demands that previously could not be met whilst potentially providing such a vast array of data that we may yet find that we still have not completely understood just how effective this may be for the future, even given the expanded usage of the data we already see in the surveys completed to date. What has also been most pleasing is that the new technique developed by Infotec was recently awarded the ‘UKSTT Product Innovation Award for 2013.’ This is a major recognition of our company’s efforts in expanding survey capabilities.”
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