Automated Sewer Inspection

The Emschergenossenschaft has been planning the modernization of its existing above ground sewer system since 1990. In the future, subterranean sewers will drain off sewage and clean water will again flow in the river Emscher. The Emscher sewer system is the heart of this future sewage disposal system. With a total length of 51 km and depths of up to 40 m beneath the surface, the Emscher sewer system is the largest residential water management project in Europe. Pipe diameters are between DN 1600 and DN 2800.

Inspection and Cleaning Robots for Sewer Systems

Operating non-stop, the Emscher sewer system will have constant filling levels between 25 and 90 percent and cannot be temporarily drained. Consequently, conventional walk-through inspection is impossible.

Engaged by the Emschergenossenschaft as the general contractor since 2002, the Fraunhofer Institute for Factory Operation and Automation IFF in Magdeburg has been developing the following automated inspection and cleaning systems for the constantly partially filled Emscher sewer system:

Image processing for the inspection with service robots: Examples from sewer inspection cover VR visualization with operation and navigation in large amounts of data, automatic crack detection, automatic joint detection and measurement as well as visual tracking for positioning.

While inspecting and detecting the condition of the Emscher sewer system, the following types of damage are reliably detectable:

• Corrosion
• Mechanical wear
• Inhibition of flow (obstacles, deposits, incrustations)
• Deviation of position (horizontal, vertical, axial displacement)
• Cracks
• Leaks

The following subsystems and their combination have been priorities during the development of the systems for inspection and cleaning:

• Carrier systems (robots) for movement and positioning throughout the sewer
• Sensor and measuring systems to inspect the pipe condition above and below the water line and to detect deposits
• Sewer cleaning system for the removal of potential smaller deposits
• Kinematic systems to position the sensors and cleaning tools on the sewer wall
• Media supply system (power, water, data communication, etc.)
• Control system, navigation system, operation
• Data processing (sensor-specific modules for data acquisition, processing, visualization and archiving, analysis modules, acquisition and analysis software, data management
• Infrastructure: vehicles, operator console, hoist for inserting systems into and removing them from the sewer