The Experts below are selected from a list of 2664 Experts worldwide ranked by ideXlab platform

M Ishikawa - One of the best experts on this subject based on the ideXlab platform.

  • navigation of an autonomous sewer inspection robot based on stereo camera images and laser scanner data
    International Journal on Artificial Intelligence Tools, 2007
    Co-Authors: Alireza Ahrary, Li Tian, Seiichiro Kamata, M Ishikawa
    Abstract:

    Sewer environment is composed of cylindrical Pipes, in which only a few landmarks such as manholes, inlets and Pipe Joints are available for localization. This paper presents a method for navigation of an autonomous sewer inspection robot in a sewer Pipe system based on detection of landmarks. In this method, location of an autonomous sewer inspection robot in the sewer Pipe system is estimated from stereo camera images. The laser scanner data are also used to ensure accurate localization of the landmarks and reduce the error in distance estimation by image processing. The method is implemented and evaluated in a sewer Pipe test field using a prototype robot, demonstrating its effectiveness.

  • A laser scanner for landmark detection with the sewer inspection robot KANTARO
    2006 IEEE SMC International Conference on System of Systems Engineering, 2006
    Co-Authors: Alireza Ahrary, Y. Kawamura, M Ishikawa
    Abstract:

    Robot localization and navigation is one of the fundamental issues involved in robotics. The sewer environment contains only few local features such as manholes, Pipe Joints and inlets that are usable as landmarks for localization. In order to find an autonomous sewer inspection robot's way to a specified goal (manhole), it has to solve the landmark detection problem. This research describes how a new mobile laser scanner can be employed for robust and fast landmark detection. The methodology is proved with real time laser scanner data from the prototype autonomous sewer inspection robot platform, KANTARO, which carries the camera and other sensors inside the sewer Pipe

  • Self-Localization of Autonomous Sewer Robots by Using a Stereo Camera and a Laser Scanner
    2006 IEEE International Conference on Networking Sensing and Control, 2006
    Co-Authors: Alireza Ahrary, M Ishikawa
    Abstract:

    Sewer environment contains only a few features that are usable as landmarks for localization such as manholes and Pipe Joints. This research describes a method for autonomous sewer robots to navigate through a sewer Pipe system based on detection of landmarks. In this method, locations of landmarks and autonomous sewer robots in the Pipe system are computed by a laser scanner and stereo image data. The method is implemented and evaluated on a prototype robot platform operating in a dry sewer Pipe test field.

  • SoSE - A laser scanner for landmark detection with the sewer inspection robot KANTARO
    2006 IEEE SMC International Conference on System of Systems Engineering, 2006
    Co-Authors: Alireza Ahrary, Y. Kawamura, M Ishikawa
    Abstract:

    Robot localization and navigation is one of the fundamental issues involved in robotics. The sewer environment contains only few local features such as manholes, Pipe Joints and inlets that are usable as landmarks for localization. In order to find an autonomous sewer inspection robot's way to a specified goal (manhole), it has to solve the landmark detection problem. This research describes how a new mobile laser scanner can be employed for robust and fast landmark detection. The methodology is proved with real time laser scanner data from the prototype autonomous sewer inspection robot platform, KANTARO, which carries the camera and other sensors inside the sewer Pipe.

  • An autonomous sewer robots navigation based on stereo camera information
    17th IEEE International Conference on Tools with Artificial Intelligence (ICTAI'05), 2005
    Co-Authors: Alireza Ahrary, Li Tian, Seiichiro Kamata, M Ishikawa
    Abstract:

    In this paper, we propose a method for autonomous sewer robots to navigate through a sewer Pipe system based on stereo camera information. In this method, local features such as manholes and Pipe Joints are extracting as a feature pixels in the region of interest (ROI) of left image. Then, an accurate and fast stereo matching measure named linear computation is implemented in this ROI image to compute the distance between the robots and local features. Finally, the distance data can be used for navigation map in sewer Pipe system. The experimental results show that our method can provide sufficient information for autonomous sewer robots navigation

Alireza Ahrary - One of the best experts on this subject based on the ideXlab platform.

  • navigation of an autonomous sewer inspection robot based on stereo camera images and laser scanner data
    International Journal on Artificial Intelligence Tools, 2007
    Co-Authors: Alireza Ahrary, Li Tian, Seiichiro Kamata, M Ishikawa
    Abstract:

    Sewer environment is composed of cylindrical Pipes, in which only a few landmarks such as manholes, inlets and Pipe Joints are available for localization. This paper presents a method for navigation of an autonomous sewer inspection robot in a sewer Pipe system based on detection of landmarks. In this method, location of an autonomous sewer inspection robot in the sewer Pipe system is estimated from stereo camera images. The laser scanner data are also used to ensure accurate localization of the landmarks and reduce the error in distance estimation by image processing. The method is implemented and evaluated in a sewer Pipe test field using a prototype robot, demonstrating its effectiveness.

  • A laser scanner for landmark detection with the sewer inspection robot KANTARO
    2006 IEEE SMC International Conference on System of Systems Engineering, 2006
    Co-Authors: Alireza Ahrary, Y. Kawamura, M Ishikawa
    Abstract:

    Robot localization and navigation is one of the fundamental issues involved in robotics. The sewer environment contains only few local features such as manholes, Pipe Joints and inlets that are usable as landmarks for localization. In order to find an autonomous sewer inspection robot's way to a specified goal (manhole), it has to solve the landmark detection problem. This research describes how a new mobile laser scanner can be employed for robust and fast landmark detection. The methodology is proved with real time laser scanner data from the prototype autonomous sewer inspection robot platform, KANTARO, which carries the camera and other sensors inside the sewer Pipe

  • Self-Localization of Autonomous Sewer Robots by Using a Stereo Camera and a Laser Scanner
    2006 IEEE International Conference on Networking Sensing and Control, 2006
    Co-Authors: Alireza Ahrary, M Ishikawa
    Abstract:

    Sewer environment contains only a few features that are usable as landmarks for localization such as manholes and Pipe Joints. This research describes a method for autonomous sewer robots to navigate through a sewer Pipe system based on detection of landmarks. In this method, locations of landmarks and autonomous sewer robots in the Pipe system are computed by a laser scanner and stereo image data. The method is implemented and evaluated on a prototype robot platform operating in a dry sewer Pipe test field.

  • SoSE - A laser scanner for landmark detection with the sewer inspection robot KANTARO
    2006 IEEE SMC International Conference on System of Systems Engineering, 2006
    Co-Authors: Alireza Ahrary, Y. Kawamura, M Ishikawa
    Abstract:

    Robot localization and navigation is one of the fundamental issues involved in robotics. The sewer environment contains only few local features such as manholes, Pipe Joints and inlets that are usable as landmarks for localization. In order to find an autonomous sewer inspection robot's way to a specified goal (manhole), it has to solve the landmark detection problem. This research describes how a new mobile laser scanner can be employed for robust and fast landmark detection. The methodology is proved with real time laser scanner data from the prototype autonomous sewer inspection robot platform, KANTARO, which carries the camera and other sensors inside the sewer Pipe.

  • An autonomous sewer robots navigation based on stereo camera information
    17th IEEE International Conference on Tools with Artificial Intelligence (ICTAI'05), 2005
    Co-Authors: Alireza Ahrary, Li Tian, Seiichiro Kamata, M Ishikawa
    Abstract:

    In this paper, we propose a method for autonomous sewer robots to navigate through a sewer Pipe system based on stereo camera information. In this method, local features such as manholes and Pipe Joints are extracting as a feature pixels in the region of interest (ROI) of left image. Then, an accurate and fast stereo matching measure named linear computation is implemented in this ROI image to compute the distance between the robots and local features. Finally, the distance data can be used for navigation map in sewer Pipe system. The experimental results show that our method can provide sufficient information for autonomous sewer robots navigation

Seiichiro Kamata - One of the best experts on this subject based on the ideXlab platform.

  • navigation of an autonomous sewer inspection robot based on stereo camera images and laser scanner data
    International Journal on Artificial Intelligence Tools, 2007
    Co-Authors: Alireza Ahrary, Li Tian, Seiichiro Kamata, M Ishikawa
    Abstract:

    Sewer environment is composed of cylindrical Pipes, in which only a few landmarks such as manholes, inlets and Pipe Joints are available for localization. This paper presents a method for navigation of an autonomous sewer inspection robot in a sewer Pipe system based on detection of landmarks. In this method, location of an autonomous sewer inspection robot in the sewer Pipe system is estimated from stereo camera images. The laser scanner data are also used to ensure accurate localization of the landmarks and reduce the error in distance estimation by image processing. The method is implemented and evaluated in a sewer Pipe test field using a prototype robot, demonstrating its effectiveness.

  • An autonomous sewer robots navigation based on stereo camera information
    17th IEEE International Conference on Tools with Artificial Intelligence (ICTAI'05), 2005
    Co-Authors: Alireza Ahrary, Li Tian, Seiichiro Kamata, M Ishikawa
    Abstract:

    In this paper, we propose a method for autonomous sewer robots to navigate through a sewer Pipe system based on stereo camera information. In this method, local features such as manholes and Pipe Joints are extracting as a feature pixels in the region of interest (ROI) of left image. Then, an accurate and fast stereo matching measure named linear computation is implemented in this ROI image to compute the distance between the robots and local features. Finally, the distance data can be used for navigation map in sewer Pipe system. The experimental results show that our method can provide sufficient information for autonomous sewer robots navigation

Li Tian - One of the best experts on this subject based on the ideXlab platform.

  • navigation of an autonomous sewer inspection robot based on stereo camera images and laser scanner data
    International Journal on Artificial Intelligence Tools, 2007
    Co-Authors: Alireza Ahrary, Li Tian, Seiichiro Kamata, M Ishikawa
    Abstract:

    Sewer environment is composed of cylindrical Pipes, in which only a few landmarks such as manholes, inlets and Pipe Joints are available for localization. This paper presents a method for navigation of an autonomous sewer inspection robot in a sewer Pipe system based on detection of landmarks. In this method, location of an autonomous sewer inspection robot in the sewer Pipe system is estimated from stereo camera images. The laser scanner data are also used to ensure accurate localization of the landmarks and reduce the error in distance estimation by image processing. The method is implemented and evaluated in a sewer Pipe test field using a prototype robot, demonstrating its effectiveness.

  • An autonomous sewer robots navigation based on stereo camera information
    17th IEEE International Conference on Tools with Artificial Intelligence (ICTAI'05), 2005
    Co-Authors: Alireza Ahrary, Li Tian, Seiichiro Kamata, M Ishikawa
    Abstract:

    In this paper, we propose a method for autonomous sewer robots to navigate through a sewer Pipe system based on stereo camera information. In this method, local features such as manholes and Pipe Joints are extracting as a feature pixels in the region of interest (ROI) of left image. Then, an accurate and fast stereo matching measure named linear computation is implemented in this ROI image to compute the distance between the robots and local features. Finally, the distance data can be used for navigation map in sewer Pipe system. The experimental results show that our method can provide sufficient information for autonomous sewer robots navigation

Guoqiang Li - One of the best experts on this subject based on the ideXlab platform.

  • Nonlinear Model of Torsional Fracture in Adhesive Pipe Joints
    ASME 2010 Pressure Vessels and Piping Conference: Volume 6 Parts A and B, 2010
    Co-Authors: Zhenyu Ouyang, Guoqiang Li, Wei Xu, Gefu Ji, H. Dwayne Jerro, Su-seng Pang
    Abstract:

    Adhesively bonded Pipe Joints are extensively used in Pipelines. In the present work, Cohesive Zone Model (CZM) based analytical solutions are derived for the bonded Pipe Joints under torsional loading. A general expression of interfacial fracture resistance for adhesive Pipe Joints is derived which is suitable for arbitrary type of nonlinear interfacial laws under torsional loading. It is found that, when the bond length of the Pipe joint is sufficiently long, the torsion load capacity is indeed independent of the shape of cohesive laws and the bond length. It is interesting to note that the maximum torsion load capacity is achieved when the torsion stiffness of the Pipe and coupler are identical. A good agreement with the previous finite element analysis (FEA) result indicates that the current model works well. This model deepens the understanding of the interfacial debonding problem of bonded Joints under torsional loading. The fracture energy based formulas of the torsion load capacity derived in the present work can be directly used in the design of adhesively bonded Pipe Joints.Copyright © 2010 by ASME

  • cohesive zone model based analytical solutions for adhesively bonded Pipe Joints under torsional loading
    International Journal of Solids and Structures, 2009
    Co-Authors: Zhenyu Ouyang, Guoqiang Li
    Abstract:

    Abstract Adhesively bonded Pipe Joints are extensively used in Pipelines. In the present work, cohesive zone model (CZM) based analytical solutions are derived for the bonded Pipe Joints under torsion. The concept of the minimum relative interface rotation ϕ m is introduced and used as the fundamental variable to express all other parameters, such as external torsion load, distribution of interfacial shear stress, length of elastic zone and softening zone, etc. It is found that when the bond length of the Pipe joint is longer than a certain value, further increase in bond length cannot bring any significant increase in torsion load capacity. Given that the bond length of the Pipe joint is long enough, the torsion load capacity is indeed independent of the shape of cohesive laws and the bond length. Consequently, simplified expressions of the torsion load capacity are derived as a function of the interface fracture energy, torsion stiffness of the Pipe, and the geometric properties of the Pipe Joints. Depending on the torsion stiffness ratio of the Pipe and the coupler, the macroscopic-debonding can initiate at the right end, left end or both ends simultaneously. It is interesting to note that the maximum torsion load capacity is achieved when the torsion stiffness of the Pipe and the coupler are identical. Good agreement with finite element analysis (FEA) result validates the accuracy of the current model. Fracture energy based formulas of the torsion load capacity derived in the present work can be directly used in the design of adhesively bonded Pipe Joints.

  • Interfacial debonding of Pipe Joints under torsion loads: a model for arbitrary nonlinear cohesive laws
    International Journal of Fracture, 2009
    Co-Authors: Zhenyu Ouyang, Guoqiang Li
    Abstract:

    Adhesively bonded Pipe Joints are extensively used in Pipelines. In the present work, Cohesive Zone Model (CZM) based analytical solutions are obtained for the bonded Pipe Joints under torsion. An integral form based general expression is derived which is suitable for arbitrary type of nonlinear cohesive laws. The concept of the minimum interfacial cohesive shear slip δ _ m is introduced and used in the fundamental expression of the external torsion load. It is found that, when the bond length of the Pipe joint is large enough, the torsion load capacity is indeed independent of the shape of cohesive laws and the bond length. It is interesting to note that the maximum torsion load capacity is achieved when the torsion stiffness of the Pipe and coupler are identical. A good agreement with finite element analysis (FEA) result indicates that the current model works well. The formulation to develop a simple test method for determining the τ – δ constitutive relationship in Pipe Joints under torsional loads is suggested. Parametric studies of various cohesive laws are conducted. This model deepens the understanding of the interfacial debonding problem of bonded Joints. The fracture energy based formulas of the torsion load capacity derived in the present work can be directly used in the design of adhesively bonded Pipe Joints.

  • light intensity effect on uv cured frp coupled composite Pipe Joints
    Composite Structures, 2004
    Co-Authors: Jerry Peck, Guoqiang Li, Su-seng Pang, Michael A Stubblefield
    Abstract:

    Abstract In this study, 36 composite Pipes were joined with an eight-layer chopped mat and woven fabric that was adhered with UV curing vinylester resin. The joined composite Pipes were cured vertically with UV lamps at three different light intensities: 80, 35, and 15 m W/cm 2 . The mechanical properties of the cured Pipes were evaluated by conducting internal pressure testing and simply supported 4-point bending testing. The effect of UV light intensity on the internal pressure rating, the ultimate bending load, and stiffness was evaluated based on the test results. A finite element analysis, which considered the under-curing along the axial direction and radial direction, was conducted to validate the test results. There was a direct correlation observed between increased light intensity and increased residual mechanical properties such as internal pressure rating, stiffness and peak failure load. The mechanisms for variation in the system properties were found to be under-curing and non-uniform curing in the FRP joint resulting in a loss of ability to effectively transfer load from the Pipe to the joint. Additional observed phenomenon was gravity leaching due to vertical curing. All mechanisms were simulated by the introduction of a sliding modulus technique in the conducted finite element analysis. FEA results agreed well with the observed failure modes.