Real-Time 3D Profiling with RGB-D Mapping in Pipelines Using Stereo Camera Vision and Structured IR Laser Ring

Abstract

This paper is focused on delivering a solution that can scan and reconstruct the 3D profile of a pipeline in realtime using a crawler robot. A structured infrared (IR) laser ring projector and a stereo camera system are used to generate the 3D profile of the pipe as the robot moves inside the pipe. The proposed stereo system does not require field calibrations and it is not affected by the lateral movement of the robot, hence capable of producing an accurate 3D map. The wavelength of the IR light source is chosen to be non overlapping with the visible spectrum of the color camera. Hence RGB color values of the depth can be obtained by projecting the 3D map into the color image frame. The proposed system is implemented in Robotic Operating System (ROS) producing real-time RGB-D maps with defects. The defect map exploit differences in ovality enabling real-time identification of structural defects such as surface corrosion in pipe infrastructure. The lab experiments showed the proposed laser profiling system can detect ovality changes of the pipe with millimeter level of accuracy and resolution.

Determination of Internal Elevation Fluctuation from CCTV Footage of Sanitary Sewers Using Deep Learning

“…The water level becomes lower in Figure 8d,e and then higher again in Figure 8f. The error rate of water levels calculated by the methodology proposed in this study is relatively lower than that of the results obtained using specific measuring instruments, such as lasers [5,6], ultrasonic devices [7,8], sonar [9], and CCTV with electronic tilt meter [10]. Factors that can affect the error of the results obtained using the measuring instruments are the error of the measuring instrument itself and errors due to the complex state of the sewer pipe.…”

“…Because the irregularity of the gradient inside the sewer pipe causes the problems described above, many studies have been conducted to accurately investigate the problems inside the sewer pipe. Some examples are related to profiling inside the sewer pipe using instruments such as lasers [5,6], ultrasonic devices [7,8], sonar [9], and CCTV with electronic tilt meter [10], which have been used to construct a profile of the inside of a sewer pipe. These types of precise instruments exhibit excellent performance compared to CCTV investigations.…”

Evaluation of Battery-free UHF-RFID Sensor Wireless Signals for In-pipe Robotic Applications

“…However, if the linings are not applied properly, they could deteriorate in the short-term, and in longterm, surface defects such as folds, wrinkles, bulges, and dimples can occur as a result of the pipe's adverse conditions. We have developed a mobile robotic system equipped with a laser profiler for three-dimensional (3D) mapping of water and wastewater pipeline internal surface defects [9], [10]. However, effective robot localization is required to track the evolution of surface defects over time by comparing 3D pipe maps acquired through robotic laser scans at various times.…”

Using UHF-RFID Signals for Robot Localization Inside Pipelines

“…Depending on the size of the pipe, average corroded pipe repair costs range from A$400 to A$4000 per metre. There are several inspection methodologies based on pulsed Eddy current sensors [2], laser profilers and stereo vision [3], electrical resistivity sensors [4], fibre optic sensors [5], drilling mechanisms [6], ultrasound sensing [7], infrared radiometers [8] to name a few are currently used to identify hot spot corrosion zones in the water utility pipelines. Based on the level of pipe degradation, the water utilities either choose to replace that respective section of the pipe or apply protective pipe linings to extend the service life of the pipe section [9].…”