A study of an autonomous mobile robot for a sewer inspection system

Pipeline network is one of the city's critical infrastructures, such as lots of gas pipes and water pipes exist in public utilities, factories and so on. Regular inspection is required to ensure the static integrity of the pipes and to insure against the problems associated with failure of the pipes. We have developed a pipeline inspection robot equipped with a camera which can walk in the pipes and stream back live video to the base station. In this paper we propose a new method for estimating the posture of the robot in round pipes with a 2D Laser Rang Finder (LRF) and a dual tilt-sensor by using the geometrical characteristic of the round pipes constructed with the point cloud data. Transformation matrix from the robot coordinate system to the global system is deduced. The positions and sizes of pipe defects can be calculated easily relying on the range data and images. Experiments by the inspection robot in dry smooth HDPE pipes are carried out and the results show that the proposed method is useful and valid.

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“…So far we obtain the transformation matrix T G A as shown in the formula (2). The posture of the robot is also estimated…”

Section: Translation Vectormentioning

confidence: 99%

Estimating the posture of pipeline inspection robot with a 2D Laser Rang Finder

Song

Zhu

2012

2012 IEEE International Conference on Multisensor Fusion and Integration for Intelligent Systems (MFI)

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“…Since we did not know if μ estimated from one pair of tendon/sheath can be generalized to another pair and a different piece of tendon/sheath was used in the length test than the angle test, we used method (2) to estimate both coefficients in order to assess the variation of μ between different TSS combinations. All TSS had a half-circle segment of length 0.3 m in the middle, then completed with two straight lines of equal length that were mounted to the platform.…”

Section: The Length Effectmentioning

confidence: 99%

Modeling tendon-sheath mechanism with flexible configurations for robot control

2013

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Surgical and search/rescue robots often work in environments with very strict spatial constraints. The tendon-sheath mechanism is a promising candidate for driving such systems, allowing power sources and actuation motors placed outside to transmit force and energy to the robot at the distal end through the constrained environment. Having both compactness and high force capability makes it very attractive for manipulation devices. On the other hand, the friction attenuation of tendon tension is nonlinear and configuration-dependent due to tendon/sheath interactions throughout the transmission path. This is a major obstacle for the tendon-sheath mechanism to be widely adopted. Here, we focus on the friction analysis for flexible and time-varying tendon-sheath configurations: the most challenging but yet commonly encountered case for real-world applications. Existing results on fixed-path configurations are reviewed, revisited, and extended to flexible and time-varying cases. The effect of tendon length to friction attenuation is modeled. While focusing on tension transmission, tendon elongation is also discussed with the length effect applied. In the end, two-dimensional results are extended to three-dimensional tendon-sheath configurations. All propositions and theorems are validated on a dedicated experimental platform.

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“…To evaluate the performance of the proposed system in the real world, we use the prototype autonomous mobile robot, KANTARO (13) , designed for inspecting sewer pipe net. It can move autonomously through 200-300mm diameter sewer pipes and also carry various sensors such as a camera and a 2D laser scanner.…”

Section: Detection In the Real Worldmentioning

confidence: 99%

An Automated Intelligent Fault Detection System for Inspection of Sewer Pipes

2007

Self Cite

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Alireza Ahrary Non-member (FAIS-Robotics Development Support Office, ali@ksrp.or.jp) Yoshinori Kawamura Non-member (Yaskawa Electric Corporation, kmura@yaskawa.co.jp) Masumi Ishikawa Member (Kyushu Institute of Technology, ishikawa@brain.kyutech.ac.jp) Keywords: intelligent system, automation, fault detection, sewer pipe system. Pipe walls in sewer systems are prone to be damaged due to aging, traffic and chemical reactions, through which inflow such as rainwater and groundwater seeps into pipe systems. Regional city government reports state that this inflow amounts to approximately 30% of the total flow. In addition to the inflow of groundwater into sewer pipes, outflow from damaged systems also occurs, contaminating the surrounding environment.Basically, maintenance or inspection process starts by collecting information about the utility. It highlights useful information about conditions of the utility such as the number and the location of faults.Conventional inspection of a sewer pipe system is carried out using a cable-tethered robot with an onboard video camera system. An operator remotely controls the movement of the robot and the video system. By this video-supported visual inspection, any notable damages or abnormalities are recorded in video stream. The reliability of this system depends on the experience of an operator. The system is also prone to human error, and tends to be time consuming and expensive. Consequently, effective automated online techniques to identify and extract objects of interest such as cracks are of immediate concern.All previous works focused on specific types of faults in pipes and none of them proposes a method for detecting various types of faults. Accordingly, an automated fault detection system is not available in the real world. In this study, we propose a method for detecting faulty areas based on images, and propose an automated intelligent system designed to facilitate diagnosis of faulty areas in a sewer pipes system. The system utilizes image analysis and efficient techniques for providing the location and the number of faults in a sewer pipe system. An overview of the automated intelligent fault detection system is shown in Fig.1. Digital images of sewer pipes taken by the camera system on the inspection robot are given to the fault detection system. The system, then, extracts a global ring ROI image to which edge enhancement is applied as preprocessing. Next, a newly defined measure of horizontal similarity is computed in order to extract candidates for visible faulty area in the ring ROI areas. Conjecture here is that the measure of similarity between images without faulty area is large. Hence, we focus on the area where the horizontal similarity value is smaller than a horizontal threshold, th h , ranged between 0 and 1. Next, we extract a rectangular ROI and compute the vertical similarity value in the candidate faulty areas. Here, the area with vertical similarity value smaller than a vertical threshold, thv, is defined as a faulty area. The proposed approac...

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A study of an autonomous mobile robot for a sewer inspection system

Cited by 24 publications

References 3 publications

Estimating the posture of pipeline inspection robot with a 2D Laser Rang Finder

Estimating the posture of pipeline inspection robot with a 2D Laser Rang Finder

Modeling tendon-sheath mechanism with flexible configurations for robot control

An Automated Intelligent Fault Detection System for Inspection of Sewer Pipes

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