The Experts below are selected from a list of 291 Experts worldwide ranked by ideXlab platform

H. Peremans - One of the best experts on this subject based on the ideXlab platform.

  • Broadband 3-D Sonar System Using a Sparse Array for Indoor Navigation
    IEEE Transactions on Robotics, 2013
    Co-Authors: Jan Steckel, Andre Boen, H. Peremans
    Abstract:

    Array beamforming techniques allow for the generation of 3-D spatial filters which can be used to localize objects in a large field of view (FOV) without the need for mechanical scanning. By combining broadband beamforming with a sparse, random array of receivers, we have constructed a low-cost, yet powerful, in-air Sonar System, which is suited for a wide range of robotic applications. Experimental results in unmodified office environments show the performance of the Sonar sensor. In particular, we document the sensor's capacity to produce 3-D location measurements in the presence of multiple highly overlapping echoes. We show how this capability makes possible the combination of a wide FOV with accurate 3-D localization, allowing the sensor to operate under real-time constraints in realistic environments. To demonstrate the use of this sensor, we describe an odometry application that estimates egomotion of a mobile robot using acoustic flow.

  • A Sonar System using a sparse broadband 3D array for robotic applications
    2012 IEEE RSJ International Conference on Intelligent Robots and Systems, 2012
    Co-Authors: Jan Steckel, Andre Boen, H. Peremans
    Abstract:

    We describe how, by combining broadband beamforming with a sparse, random array of receivers, we have constructed a low-cost, yet powerful, in-air Sonar System which is suited for a wide range of robotic applications. In particular, we show how simple array beamforming techniques allow for the generation of 3D spatial filters that can be used to accurately localize objects in a large field of view without the need for mechanical scanning. Experimental validation of the sensor's capacity to produce 3D location measurements in the presence of multiple highly overlapping echoes is presented.

  • 3D localization by a biomimetic Sonar System in a fire-fighting application
    Proceedings - 4th International Congress on Image and Signal Processing CISP 2011, 2011
    Co-Authors: Jan Steckel, Wouter Vanduren, H. Peremans
    Abstract:

    In this study we investigate the effects of medium disturbances on the usability of a biomimetic Sonar System in a target localization application. In particular, we concentrate on a fire-fighting application giving rise to specific types of medium disturbances. We determine experimentally the effects of these medium disturbances: undisturbed air (reference), the presence of small water droplets, large convective air-currents and flames, on the received echo spectra. As the echo spectra are used to estimate the target location, these different conditions by disturbing to varying extents sound propagation through the medium will have an effect on the Sonar System's localization performance. Using an information theoretic model of the spectrum based localization mechanism we characterize the loss in localization accuracy due to the different medium disturbances. We conclude that an echolocation System based on the Sonar System of the bat Phyllostomus discolor allows for robust localization even in highly disturbed media. However, while the need for replacing the emission pattern of the bat by that of a standard transducer in the biomimetic Sonar System makes little difference in the &x2018;reference&x2019; and &x2018;water spray&x2019; conditions it limits echolocation performance in the &x2018;air-currents&x2019; condition and makes the use of the proposed System very difficult in the &x2018;flames&x2019; condition.

  • Biomimetic Sonar System Performing Spectrum-Based Localization
    IEEE Transactions on Robotics, 2007
    Co-Authors: Jonas Reijniers, H. Peremans
    Abstract:

    In this paper, we study echolocation by spectral analysis as a biomimetic, i.e., inspired by bats, mechanism to observe a realistic environment. We propose a method to localize, i.e., to estimate the distance and bearing of reflectors, on the basis of a time-frequency representation of the returned echo similar to the one derived by the bat's cochlea. The Sonar System consists of a central transmitter, and two receivers pointing plusmn5deg outward. The method proposed reconstructs the environment by comparing the returned echoes with binaural spectral templates corresponding with echoes from different angles. We further show that a distance matrix defined on the set of templates can be used as a measure of their accuracy and reliability for localization purposes. We include experimental results that validate the System and indicate that it can deal with the complex echo signals received when confronted with realistic reflectors, i.e., possibly consisting of a large number of closely spaced scatterers.

Seong Hak Park - One of the best experts on this subject based on the ideXlab platform.

  • Design and optimization of a 2-link type overboarding mechanism for the drop/lift automation of an active/passive Sonar System in a surface ship
    2016 IEEE International Conference on Mechatronics and Automation, 2016
    Co-Authors: Seok Jeong Kang, Seong Hak Park, Won Jee Chung, Jong Kap Choi, Yoo Seong Jeong, Hyo Gon Kim
    Abstract:

    Active/passive type Sonar Systems have the receiving array that measures sound waves, transmitter towed body that converts sound waves, transmitter towing cable that controls the depth of the transmitter towed body, and array cable that connects the receiving array and transmitter towed body. With the research on the active/passive Sonar System, a variety of mechanisms of the overboarding unit suitable for the limited environments have been developed. The link mechanism for efficient drop/lift of Sonar System was researched in the paper of Park et al. [2] However, single link and actuator were used here that structural stability is lacked. Also, efficiency of storage also falls because complete storage inside the hull is impossible. In this paper, a sub-actuator is added in the bottom part to strength the stability of drop/lift of Sonar equipment in which a link mechanism is designed to enable complete storage in the hull through the optimization of GA (Genetic Algorithm) method using MATLAB®. The mechanism proposed in this paper is 2-link type with 2 actuators equipped and is classified into the main link part and sub-link part for kinematic analysis and optimization. Reduction of required space and stability is secured compared to the Park et al.'s mechanism. This will have great advantage in the aspect of work efficiency and safety of workers, and maintenance.

  • Design and optimization of an efficient overboarding mechanism for the drop/lift automation of an active/passive Sonar System in a surface ship
    2015 IEEE International Conference on Mechatronics and Automation (ICMA), 2015
    Co-Authors: Seong Hak Park, Won Jee Chung, Jong Kap Choi, Jin Woong Sa
    Abstract:

    An active/passive Sonar System consists of 1) a transmitter towing cable for adjusting the depth of the transmitter towed body, 2) a receiving array for measuring sound waves, 3) a transmitter towed body for transforming sound waves and 4) an array cable for connecting a receiving array to a transmitter towed body. There is a need to develop an automated equipment to drop the active/passive Sonar System into the deep sea from the surface ship and then lift it, since this consists of a cable with a length of over 1000m, a transmitter towed body, etc. With the research on the active/passive Sonar System, a variety of mechanisms of the overboarding unit suitable for the limited environments have been developed. This paper suggests a new overboarding mechanism which is efficient in operation and maintenance of the Sonar System. First, we analyzes the strengths and weaknesses of the existing overboarding mechanisms, and then suggest a new mechanism to improve these problems. For the proposed mechanism, we will treat with a technique to optimize the link length and the actuator length for the mechanism not to interfere in the hull's internal environment, to satisfy work ROM (Range of Motion) and to have good torque-angle properties. Our approach will be helpful for calculating the maximized output torque of the actuator for the actual application of a similar type of the proposed mechanism in practice.

Jin Woong Sa - One of the best experts on this subject based on the ideXlab platform.

  • Design and optimization of an efficient overboarding mechanism for the drop/lift automation of an active/passive Sonar System in a surface ship
    2015 IEEE International Conference on Mechatronics and Automation (ICMA), 2015
    Co-Authors: Seong Hak Park, Won Jee Chung, Jong Kap Choi, Jin Woong Sa
    Abstract:

    An active/passive Sonar System consists of 1) a transmitter towing cable for adjusting the depth of the transmitter towed body, 2) a receiving array for measuring sound waves, 3) a transmitter towed body for transforming sound waves and 4) an array cable for connecting a receiving array to a transmitter towed body. There is a need to develop an automated equipment to drop the active/passive Sonar System into the deep sea from the surface ship and then lift it, since this consists of a cable with a length of over 1000m, a transmitter towed body, etc. With the research on the active/passive Sonar System, a variety of mechanisms of the overboarding unit suitable for the limited environments have been developed. This paper suggests a new overboarding mechanism which is efficient in operation and maintenance of the Sonar System. First, we analyzes the strengths and weaknesses of the existing overboarding mechanisms, and then suggest a new mechanism to improve these problems. For the proposed mechanism, we will treat with a technique to optimize the link length and the actuator length for the mechanism not to interfere in the hull's internal environment, to satisfy work ROM (Range of Motion) and to have good torque-angle properties. Our approach will be helpful for calculating the maximized output torque of the actuator for the actual application of a similar type of the proposed mechanism in practice.

Jan Steckel - One of the best experts on this subject based on the ideXlab platform.

  • Sonar System combining an emitter array with a sparse receiver array for air-coupled applications
    IEEE Sensors Journal, 2015
    Co-Authors: Jan Steckel
    Abstract:

    In this paper, we describe the application of an emitter array based on simultaneous transmit-synthetic aperture beamforming (ST-STAB) to improve the signal-to-noise ratio in an existing, 3-D, air-coupled Sonar System. The ST-STAB approach allows for the simultaneous emission of orthogonal codes by an array of emitters, which are decoded in the receiver stage, eliminating the need for multiple measurement cycles. By adding more emitters to the sensor System, the overall emitted acoustic energy is increased, while the ST-STAB approach ensures an efficient use of measurement time. We elaborate on the mathematical model of the sensor and signal processing System, provide the associated point spread functions and show experimental validation the constructed prototype array.

  • Broadband 3-D Sonar System Using a Sparse Array for Indoor Navigation
    IEEE Transactions on Robotics, 2013
    Co-Authors: Jan Steckel, Andre Boen, H. Peremans
    Abstract:

    Array beamforming techniques allow for the generation of 3-D spatial filters which can be used to localize objects in a large field of view (FOV) without the need for mechanical scanning. By combining broadband beamforming with a sparse, random array of receivers, we have constructed a low-cost, yet powerful, in-air Sonar System, which is suited for a wide range of robotic applications. Experimental results in unmodified office environments show the performance of the Sonar sensor. In particular, we document the sensor's capacity to produce 3-D location measurements in the presence of multiple highly overlapping echoes. We show how this capability makes possible the combination of a wide FOV with accurate 3-D localization, allowing the sensor to operate under real-time constraints in realistic environments. To demonstrate the use of this sensor, we describe an odometry application that estimates egomotion of a mobile robot using acoustic flow.

  • A Sonar System using a sparse broadband 3D array for robotic applications
    2012 IEEE RSJ International Conference on Intelligent Robots and Systems, 2012
    Co-Authors: Jan Steckel, Andre Boen, H. Peremans
    Abstract:

    We describe how, by combining broadband beamforming with a sparse, random array of receivers, we have constructed a low-cost, yet powerful, in-air Sonar System which is suited for a wide range of robotic applications. In particular, we show how simple array beamforming techniques allow for the generation of 3D spatial filters that can be used to accurately localize objects in a large field of view without the need for mechanical scanning. Experimental validation of the sensor's capacity to produce 3D location measurements in the presence of multiple highly overlapping echoes is presented.

  • 3D localization by a biomimetic Sonar System in a fire-fighting application
    Proceedings - 4th International Congress on Image and Signal Processing CISP 2011, 2011
    Co-Authors: Jan Steckel, Wouter Vanduren, H. Peremans
    Abstract:

    In this study we investigate the effects of medium disturbances on the usability of a biomimetic Sonar System in a target localization application. In particular, we concentrate on a fire-fighting application giving rise to specific types of medium disturbances. We determine experimentally the effects of these medium disturbances: undisturbed air (reference), the presence of small water droplets, large convective air-currents and flames, on the received echo spectra. As the echo spectra are used to estimate the target location, these different conditions by disturbing to varying extents sound propagation through the medium will have an effect on the Sonar System's localization performance. Using an information theoretic model of the spectrum based localization mechanism we characterize the loss in localization accuracy due to the different medium disturbances. We conclude that an echolocation System based on the Sonar System of the bat Phyllostomus discolor allows for robust localization even in highly disturbed media. However, while the need for replacing the emission pattern of the bat by that of a standard transducer in the biomimetic Sonar System makes little difference in the &x2018;reference&x2019; and &x2018;water spray&x2019; conditions it limits echolocation performance in the &x2018;air-currents&x2019; condition and makes the use of the proposed System very difficult in the &x2018;flames&x2019; condition.

Jong Kap Choi - One of the best experts on this subject based on the ideXlab platform.

  • Design and optimization of a 2-link type overboarding mechanism for the drop/lift automation of an active/passive Sonar System in a surface ship
    2016 IEEE International Conference on Mechatronics and Automation, 2016
    Co-Authors: Seok Jeong Kang, Seong Hak Park, Won Jee Chung, Jong Kap Choi, Yoo Seong Jeong, Hyo Gon Kim
    Abstract:

    Active/passive type Sonar Systems have the receiving array that measures sound waves, transmitter towed body that converts sound waves, transmitter towing cable that controls the depth of the transmitter towed body, and array cable that connects the receiving array and transmitter towed body. With the research on the active/passive Sonar System, a variety of mechanisms of the overboarding unit suitable for the limited environments have been developed. The link mechanism for efficient drop/lift of Sonar System was researched in the paper of Park et al. [2] However, single link and actuator were used here that structural stability is lacked. Also, efficiency of storage also falls because complete storage inside the hull is impossible. In this paper, a sub-actuator is added in the bottom part to strength the stability of drop/lift of Sonar equipment in which a link mechanism is designed to enable complete storage in the hull through the optimization of GA (Genetic Algorithm) method using MATLAB®. The mechanism proposed in this paper is 2-link type with 2 actuators equipped and is classified into the main link part and sub-link part for kinematic analysis and optimization. Reduction of required space and stability is secured compared to the Park et al.'s mechanism. This will have great advantage in the aspect of work efficiency and safety of workers, and maintenance.

  • Design and optimization of an efficient overboarding mechanism for the drop/lift automation of an active/passive Sonar System in a surface ship
    2015 IEEE International Conference on Mechatronics and Automation (ICMA), 2015
    Co-Authors: Seong Hak Park, Won Jee Chung, Jong Kap Choi, Jin Woong Sa
    Abstract:

    An active/passive Sonar System consists of 1) a transmitter towing cable for adjusting the depth of the transmitter towed body, 2) a receiving array for measuring sound waves, 3) a transmitter towed body for transforming sound waves and 4) an array cable for connecting a receiving array to a transmitter towed body. There is a need to develop an automated equipment to drop the active/passive Sonar System into the deep sea from the surface ship and then lift it, since this consists of a cable with a length of over 1000m, a transmitter towed body, etc. With the research on the active/passive Sonar System, a variety of mechanisms of the overboarding unit suitable for the limited environments have been developed. This paper suggests a new overboarding mechanism which is efficient in operation and maintenance of the Sonar System. First, we analyzes the strengths and weaknesses of the existing overboarding mechanisms, and then suggest a new mechanism to improve these problems. For the proposed mechanism, we will treat with a technique to optimize the link length and the actuator length for the mechanism not to interfere in the hull's internal environment, to satisfy work ROM (Range of Motion) and to have good torque-angle properties. Our approach will be helpful for calculating the maximized output torque of the actuator for the actual application of a similar type of the proposed mechanism in practice.