The maintenance and potential rehabilitation requirements of pipeline infrastructure has seen exponential advances in technology over recent years with innovative new approaches to evaluation and measurement from pipe profiling and 3D modelling to crack width measurement and digital imaging leading the field.

The latest innovation, PANORAMO, embraces a radical new approach to pipeline inspection and is set to revolutionise the industry in Australasia as it has in Europe. To understand PANORAMO and its benefits we must first understand the limitations of conventional CCTV systems and the differences between the two.

A recent study conducted by Consulting Engineers Prof. Dr. Ing. Stein & Partner GmbH, Bochum, Germany (S&P) investigated the performance of the PANORAMO system against a conventional CCTV system, the Argus 4, with astonishing results. The tests were conducted in areas of the sewer system of the Wuppertaler Stadwerke AG utilising as broad a cross-section of different pipe materials, lengths and diameters as possible. The aim was to establish whether the requirements of a new system like PANORAMO were justified and to demonstrate its possibilities.

Of the inspected pipe sections, 19.2 per cent consisted of concrete pipes, 34.5 per cent of RC pipes, 40.7 per cent of VC pipes and 5.6 per cent of brick pipes. The section lengths varied from 93.2 m up to 409.1 m with diameters ranging from 250 mm up to 1000 mm and a total pipe survey length over the experiment of 2.4 km.

The appraisal and analysis of the results obtained from the investigation was conducted with a view to determining the performance of one system against the other with specific regard to inspection performance, inspection quality, and of course economics.

Inspection performance

Inspection performance was measured in terms of the net in-pipe inspection time including all stops made for defect identification and feature observation over the full section length, that is, from the point of entry into the pipe to the point of extraction. The times were recorded and averaged for both systems over the entire surveyed network to yield the mean survey speed of each.

Argus 4 was found to yield an average speed of 37.5 mm per second whereas the PANORAMO was found to yield an average speed 242.5 mm per second – six and a half times faster than the Argus.

It was noted in the report that, “In the in-situ investigations in Wuppertal with Argus 4, the velocity determined from the net inspection time in the sewer to be inspected and including all stops for viewing damage and the input of damage abbreviations was an average of 3.75 cm/s. As expected, a clearly higher average value of 24.25 cm/s was measured for PANORAMO.”

Other aspects of the survey routine were also timed, including set-up and pack-up times, but it was found that in all cases the differences between the two systems were negligible.

Inspection quality

Inspection quality was measured in terms of picture clarity, sharpness and expressiveness and image format.

As with most CCTV systems currently available, Argus 4 uses component video at 25 frames per second and stores them digitally in MPeg 2 format at 4 Mbit/s. The camera is a 1 lux colour camera with a resolution of 450 TVL and has a pan & tilt capability of 340o x 240o. It is equipped with a 2:1 zoom lens, automatic iris, adjustable focus, 7 x 35 watt halogen lamps and offers the patented ROTAX® right-side-up picture technology. The Argus 4 is widely considered to be one of the more advanced CCTV systems available.

The mechanics of PANORAMO, however, are quite different. Unlike any other system past or present, PANORAMO enables the viewer to examine the entire internal wall of the pipe, including every feature and every defect within it. It records each detail from all possible angles without the need to stop, pan, tilt, focus or interact in any way. After a single pass the survey is complete with everything retained in the patented IPF (IBAK PANORAMO Film) digital file format, making it available for potentially any form of manipulation or interrogation in the future.

The pipe can be illuminated, rotated, traversed upstream or downstream. Defects can be zoomed in on, viewed from every conceivable angle, and multiple sections can be ‘unwrapped’ and viewed, two dimensionally, enabling precision measurements and defect identification to be performed with unprecedented accuracy.

Not only is the level of clarity and quality of information gathered by PANORAMO far in excess of any other system available, so is the quantity and it is all available interactively long after the inspection is complete.

Economics

The economic tests were designed to quantify the costs of acquisition, operation and maintenance (AOM) of each system. The cost comparison method, based on KVR guidelines as referenced in the S&P report, was used as was a cost-utility analysis (CUA).

The cost comparison method permitted a comparison of the quantifiable monetary cost cash value or the annualised AOM costs of the two systems and was utilised, for the purposes of this application, assuming a benefit equality for each.

The basis for the test was the data gathered in the inspection performance tests coupled with the limitations imposed by personnel resourcing and post inspection information handling. The results were again a success for PANORAMO, as noted in the report: “Under the given limiting conditions in Wuppertal, the PANORAMO inspection system showed, a cost advantage compared to the Argus 4 camera system.”

The cost utility analysis enabled the evaluation of direct utility effects that cannot be monetised within the scope of a variant comparison (including picture quality, reliability, ease of operation and reproducibility of results) and is a method often used for carrying out utility-cost investigations.

It was noted in the report that, “The PANORAMO inspection system, compared to the Argus 4 system, showed a utility proportion of 142 per cent to 100 per cent. A corresponding cost-utility advantage was achieved for PANORAMO.”

How it works

The approach that the PANORAMO system takes is unlike anything seen before. It is a unique idea that gives the viewer complete control of the survey whether in the field or back in the office and allows the complete resource of information to be handled in any way.

The defining difference is that it uses two fixed high-resolution digital photo cameras instead of one conventional video camera. There is one camera placed at each end of the transport unit, or crawler, each with a wide-angle (fish-eye) lens and high-power Xenon flash.

The unit traverses up or down the pipe at 350 mm/s taking high-resolution digital snap shots at 50 mm intervals (seven shots a second at each end). The exposure rate is 0.0005 of a second, some 80 times faster than conventional CCTV systems, ensuring that the images retained are always crisp and clear. PANORAMO does not stop or slowdown at any point along its journey.

Due to the fish-eye lens each shot is hemispherical (360o circumferentially around the pipe and 185o longitudinally up and down the pipe) and once run through the PANORAMO software, the photos are collated to give a complete 360o x 360o sphere. These spheres are then digitally processed to into a film-like sequence that are presented in a continuous virtual-reality stream allowing the viewer to examine the pipe whichever way they like, at any point in the survey.

Because the pictures are digitally processed they can be manipulated to suit the viewer. One of the most attractive features of the system is that is can be ‘unwrapped’. This feature effectively cuts the pipe along its length, either at 12:00 or 6:00, and lays it out in a two dimensional format. This allows utilities such as crack width measurement, ‘at-a-glance’ defect identification and pixel recognition defect analysis to be performed with precision.

The report concluded by saying “In summary, it can be shown that with the PANORAMO there is available for the first time…a fully digital picture taking and processing system as well as full analysis in the office of the visual condition establishment and evaluation of drains and sewers. The in-situ investigations in Wuppertal have shown that, compared to the ARGUS 4 camera system, this inspection system is a very effective and economic alternative with a high degree of utility.”

A copy of the full report compiled by Consulting Engineers Prof. Dr.-Ing. Stein & Partner GmbH can be obtained from Austeck Pty Limited. Tel: +61 2 9338 7688. Email: info@austeck.com.