Application of visual odometry for sewer inspection robots

Large waste water pipes are a hazardous working environment for humans. Nevertheless such pipes must be inspected on a regular basis. Many of todaypsilas inspection systems for underground sewer pipes consist of a single TV-camera and are designed for pipes smaller than one meter in diameter. The most recent automatic inspection systems are equipped with advanced sensors that make it possible for an operator to perform this task from an outside position for larger pipes (diameter between 1.4 to 2.8 meters). The cable-guided damage surveying system, SEK, (see Fig. 1) was developed by the Fraunhofer IFF on behalf of the Emschergenossenschaft to be a versatile and easy-to-use tool to detect various kinds of damages above and below the water-line with high accuracy.