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Smart Sewer Assessment Systems
The Need
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The need for accurate preventive assessment of
sewer conditions is increasing world wide. Problems encountered with faulty conditions
that arise in old sewer lines are numerous. Examples of these problems are dramatic
collapses of pipelines from groundwater infiltration, and exfiltration of sewage into the
groundwater and the surrounding soil causing dramatic environmental pollution. In fact,
Germany pays an estimated 100 billion DM in restoration of failed sewer lines. As a
result, the German government has increased the requirements on sewerage facilities by
enacting relevant laws (Kuntze et al., 1995). These
problems are further magnified by the lack of proper and error proof inspection techniques
that would detect faulty conditions before sudden failure occurs. Contemporary electronic
inspection through CCTV (a remotely controlled camera-based system that goes through the
pipe and transfers images to a monitor) is not precise and error prone due to the
subjectivity and difficulty of an exact evaluation by the operator. |
KARO System
Optimess TriScan system
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The Technology
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The new method utilizes qualified inspection
systems that are automated and that utilize artificial intelligence to assess whether or
not a crack in the surface of the pipe exists. The KARO system is one example. Developed
by the German Federal Ministry of Education, Science, Research, and Technology (BMBF) and
four partners from both industry and research institutions. This system is composed of a
mobile control and surveillance station, and a mobile robot. The robot is of high maneuverability and carries intelligent multisensorics
that are based on a 3-D optical sensor, ultrasonic sensors for inside pipe inspection, as
well as a microwave sensor for the inspection of the soil surrounding the pipe wall
(Kuntze et al., 1995). Defects are detected by means of sensor signals which are
'intelligently' connected to each other. They are evaluated by means of fuzzy mathematical
methods.
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KARO System concept
 Optimess DKM tool
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Another example of a pipe condition assessment
method is the PIRAT System. Developed by CSIRO (Australia's research agency). This system
consists of an in-pipe vehicle which carries scanners and associated instruments that
monitor the sewer and a mobile control room which houses data analysis and controls. A
laser scanner is used for a drained pipe and a sonar scanner is used for flooded pipes
(Campbell et al., 1995). The laser scanner operates by analyzing reflected light using a
video camera. And the sonar scanner works by analyzing echoes that represent the features
of the pipe. Finally, the interpretation system implements artificial intelligence to
automatically classify and rate pipe defects. Finally, OPTIMESS GmbH a German company offers TriScan. A
TV-inspection system for sewage water drains, process pipes and long distance pipelines.
The camera is equipped with a special laser distance sensor. It works with high resolution
among 50 and 250 mm supplying exact spatial coordinates, so it is possible to separate and
classify objects by its dimensions, shape, and profile. The measuring system is able to
verify and determinate: pipe diameter, pipe deformations, pipe wall thickness,
cross-sectional profile, crack length and width, and degree of pipe corrosion. It can be
used for leakage localization in drinking water supply networks and inspection of
long-distance pipelines up to a length of 10 kilometers. |
The Benefits
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The development of such systems allows
objective and reliable evaluation of the obtained data for assessment of the existing pipe
conditions (damage location, type, and volume). Compared with most TV-based systems, these
systems have the extra benefit of employing intelligent multisensorics, and/or neural
network training. According to Campbell, the assessment of expert asset managers reveals
that on concrete and VC pipes, these systems exceed the performance of good CCTV
operators. Moreover, these systems have the potential of predicting or forecasting future
system deterioration. |
Status
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The KARO System is currently being applied in
Germany and in respect to the PIRAT System it has been used for the inspection of 5
kilometers of sewers in Melbourne. |
Barriers
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There is still no information on the cost
associated with such systems. Some disadvantages lie in the slower inspection speeds
required for examination of finer defects. Also, the systems do not suggest an optimal
repair method when cracks are detected. |
Points of Contact
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Karo System:
- Kuntze, H.B. - Fraunhofer
Institute for Information and Data Processing (IITB), Fraunhoferstrasse 1, D-76131
Karlsruhe, Germany. Phone: 49(0)721/6091-0. Fax: 49(0)721/6091-413
- Schmidt, D. - Ettlingen IBP PIETZSCH GmbH, Erzbergerstrasse
115/117, D-76133 Karlsruhe, Phone:49 721 97 39-0. Fax: 49 7 21 9739-1 92
- Haffner, H. - Forschungszentrum
Karlsruhe Technik und Umwelt GmbH, Postfach 3640, D-76021 Karlsruhe, Germany. Phone:
49 7247 82-0. Fax: 49 7247 825070
- Loh, M. - Brochier GmbH, Nurnberg
Pirat System:
Optimess TriScan:
- Optimess GmbH - Keplerstrasse 100, D-07549 Gera, Germany.
Phone: 49 365 7349 220. Fax: 49 365 7349 229
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References
- Campbell, G., Rogers, K., and Gilbert, J. 'PIRAT - A
system for quantitative sewer assessment', International No-Dig '95 Conference
Documentation, Dresden, September 1995.
- Kuntze, H.B., Schmidt, D., Haffner, H., Loh, M. 'KARO - A
flexible robot for smart sensor-based sewer inspection', International No-Dig '95
Conference Documentation, Dresden, September 1995.
- OPTIMESS TriScan product information.
Disclaimer Statement
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Neither the Construction
Industry Institute nor Purdue University in any way endorses this
technology or represents
that the information presented can be relied upon without further investigation. |
MMS03/LHM
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