@article{Ramos-Oliveira2019,
title = {On ray tracing for sharp changing media},
author = {Ramos-Oliveira, Jorge and Baltazar, Arturo and Castelan, Mario},
url = {https://doi.org/10.1121/1.5125133},
doi = {10.1121/1.5125133},
year = {2019},
date = {2019-07-10},
journal = {Journal of the Acoustic Society of America},
volume = {146},
number = {3},
pages = {1595-1604},
keywords = {Ray tracing},
pubstate = {published},
tppubtype = {article}
}
@article{carreon2017development,
title = {Development of a model-free force controller for soft contact of an ultrasonic test probe},
author = {Carreon, Augusto and Baltazar, Arturo and Treesatayapun, Chidentree},
year = {2017},
date = {2017-01-01},
journal = {The International Journal of Advanced Manufacturing Technology},
volume = {90},
number = {9-12},
pages = {2839--2847},
publisher = {Springer},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
@proceedings{Treesatayapun2016b,
title = {Adaptive controller based on Sigmoid-RBF for contact force testing machine},
author = {Treesatayapun, Chidentree and Baltazar, Arturo},
year = {2016},
date = {2016-09-14},
keywords = {Artificial neural networks},
pubstate = {published},
tppubtype = {proceedings}
}
@proceedings{Gallegos2016,
title = {Neuro Fuzzy Force Control for Soft Dry Contact Hertzian Ultrasonic Probe},
author = {Gallegos, E. and Baltazar, Arturo and Treesatayapun, Chidentree},
year = {2016},
date = {2016-09-14},
keywords = {Artificial neural networks},
pubstate = {published},
tppubtype = {proceedings}
}
@proceedings{Fernandez2016,
title = {A Study of Sensor Array Aperture for Damage Localization in a Plate-Like Structure Using Ultrasonic Guided Waves},
author = {Fernandez, K. and Baltazar, Arturo and Aranda, Jorge and Treesatayapun, Chidentree},
year = {2016},
date = {2016-09-14},
keywords = {acustic sensors},
pubstate = {published},
tppubtype = {proceedings}
}
@article{7118647,
title = {Determination of Contact Evolution on a Soft Hemispherical Probe Using Ultrasound},
author = {Carreon, Augusto and Baltazar, Arturo and Kim, J.},
url = {http://ieeexplore.ieee.org/document/7118647/},
doi = {10.1109/JSEN.2015.2439293},
issn = {1530-437X},
year = {2015},
date = {2015-09-01},
journal = {IEEE Sensors Journal},
volume = {15},
number = {9},
pages = {5303-5311},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
@article{0964-1726-24-7-075008,
title = {Damage detection using the signal entropy of an ultrasonic sensor network},
author = {Rojas, Erick and Baltazar, Arturo and Loh, K.},
url = {http://stacks.iop.org/0964-1726/24/i=7/a=075008},
year = {2015},
date = {2015-01-01},
journal = {Smart Materials and Structures},
volume = {24},
number = {7},
pages = {075008},
abstract = {Piezoelectric ultrasonic sensors used to propagate guided waves can potentially be implemented to inspect large areas in engineering structures. However, the inherent dispersion and noise of guided acoustic signals, multiple echoes in the structure, as well as a lack of an approximate or exact model, limit their use as a continuous structural health monitoring system. In this work, the implementation of a network of piezoelectric sensors randomly placed on a plate-like structure to detect and locate artificial damage is studied. A network of macro fiber composite (MFC) sensors working in a pitch\^{a}€“catch configuration was set on an aluminum thin plate 1.9 mm in thickness. Signals were analyzed in the time-scale domain using the discrete wavelet transform. The objectives of this work were threefold, namely to first develop a damage index based on the entropy distribution using short time wavelet entropy of the ultrasonic waves generated by a sensor network, second to determine the performance of an array of spare MFC sensors to detect artificial damage, and third to implement a time-of-arrival (TOA) algorithm on the gathered signals for damage location of an artificial circular discontinuity. Our preliminary test results show that the proposed methodology provides sufficient information for damage detection, which, once combined with the TOA algorithm, allows localization of the damage.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Piezoelectric ultrasonic sensors used to propagate guided waves can potentially be implemented to inspect large areas in engineering structures. However, the inherent dispersion and noise of guided acoustic signals, multiple echoes in the structure, as well as a lack of an approximate or exact model, limit their use as a continuous structural health monitoring system. In this work, the implementation of a network of piezoelectric sensors randomly placed on a plate-like structure to detect and locate artificial damage is studied. A network of macro fiber composite (MFC) sensors working in a pitch–catch configuration was set on an aluminum thin plate 1.9 mm in thickness. Signals were analyzed in the time-scale domain using the discrete wavelet transform. The objectives of this work were threefold, namely to first develop a damage index based on the entropy distribution using short time wavelet entropy of the ultrasonic waves generated by a sensor network, second to determine the performance of an array of spare MFC sensors to detect artificial damage, and third to implement a time-of-arrival (TOA) algorithm on the gathered signals for damage location of an artificial circular discontinuity. Our preliminary test results show that the proposed methodology provides sufficient information for damage detection, which, once combined with the TOA algorithm, allows localization of the damage.
@inproceedings{Rojas2015,
title = {Structural health monitoring method based on the entropy of an ultrasonic sensor network for a plate-like structure},
author = {Rojas, Erick and Baltazar, Arturo},
url = {http://aip.scitation.org/doi/pdf/10.1063/1.4914788},
doi = {http://dx.doi.org/10.1063/1.4914788},
year = {2015},
date = {2015-00-00},
keywords = {monitoring, network, sensor-ultrasonic},
pubstate = {published},
tppubtype = {inproceedings}
}
@article{Balvantin2014,
title = {Characterization of Laser Generated Lamb Wave Modes after Interaction with a Thickness Reduction Discontinuity Using Ray Tracing Theory},
author = {Balvantin, A. and Baltazar, Arturo and Rodriguez, P.},
url = {http://dx.doi.org/10.1007/s11340-013-9846-y},
doi = {10.1007/s11340-013-9846-y},
issn = {1741-2765},
year = {2014},
date = {2014-01-01},
journal = {Experimental Mechanics},
volume = {54},
number = {5},
pages = {743--752},
abstract = {The effect that a circular discontinuity (due to thickness reduction) in an Aluminum plate has on the direction of Lamb wave propagation was experimentally and theoretically studied. Broadband Lamb waves were generated by a pulsed Nd:YAG laser and optically detected with a photo-EMF detector to increase spatial resolution. The experimental results show that thickness reduction modifies the time of flight (TOF) for S0 and A0 vibration modes and generates a change in direction of the ultrasonic Lamb wave. The change in the TOF as a function of distance and thickness reduction was numerically determined using ray theory and then compared to experimental results. It is shown that the change in the direction of propagation depends on the vibrational mode and frequency of the Lamb waves and this can affect the detection and characterization of a hidden discontinuity.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
The effect that a circular discontinuity (due to thickness reduction) in an Aluminum plate has on the direction of Lamb wave propagation was experimentally and theoretically studied. Broadband Lamb waves were generated by a pulsed Nd:YAG laser and optically detected with a photo-EMF detector to increase spatial resolution. The experimental results show that thickness reduction modifies the time of flight (TOF) for S0 and A0 vibration modes and generates a change in direction of the ultrasonic Lamb wave. The change in the TOF as a function of distance and thickness reduction was numerically determined using ray theory and then compared to experimental results. It is shown that the change in the direction of propagation depends on the vibrational mode and frequency of the Lamb waves and this can affect the detection and characterization of a hidden discontinuity.
@article{Mijarez2014,
title = {Damage detection in ACSR cables based on ultrasonic guided waves},
author = {Mijarez, Rito and Baltazar, Arturo and Rodr\'{i}guez-Rodr\'{i}guez, Joaquin and Ram\'{i}rez-Ni\~{n}o, Jose },
url = {http://revistas.unal.edu.co/index.php/dyna/article/view/40252/53905},
doi = { https://doi.org/10.15446/dyna.v81n186.40252},
issn = {0012-7353},
year = {2014},
date = {2014-00-00},
journal = {DYNA},
volume = {81},
number = { 186},
pages = { 226-233},
abstract = {The use of ultrasonic guided waves is growing as a non-destructive testing technique of multi-wire cables used in civil engineering structures. Wave propagation characteristics in these types of structures have been challenging to investigate owing to the load-dependent inter-wire contact and the helical geometry of the peripheral wires. In this work, experiments of guided waves propagated in a 0.9m Aluminum Conductor Steel Reinforced (ACSR) cable were conducted employing two longitudinal piezoelectric transducers attached to the ends of the cable in a through transmission configuration. Longitudinal L(0,1) and flexural F(1,1) modes were identified at 500 kHz via dispersion curves and Wavelet Transforms (WT). Experiments included artificial damage introduced in the middle of the cable by cutting and gradually increasing the cut depth from 1mm to 9mm. The attained results suggest a change of guided modes excitation and reception from F(1,1) to L(0,1) due to reduced friction contact among individual wires. This change of guided waves modes in response to damage variations, associated with the transmitted ultrasonic energy, was identified and discussed as potential mean of damage monitoring.
The use of ultrasonic guided waves is growing as a non-destructive testing technique of multi-wire cables used in civil engineering structures. Wave propagation characteristics in these types of structures have been challenging to investigate owing to the load-dependent inter-wire contact and the helical geometry of the peripheral wires. In this work, experiments of guided waves propagated in a 0.9m Aluminum Conductor Steel Reinforced (ACSR) cable were conducted employing two longitudinal piezoelectric transducers attached to the ends of the cable in a through transmission configuration. Longitudinal L(0,1) and flexural F(1,1) modes were identified at 500 kHz via dispersion curves and Wavelet Transforms (WT). Experiments included artificial damage introduced in the middle of the cable by cutting and gradually increasing the cut depth from 1mm to 9mm. The attained results suggest a change of guided modes excitation and reception from F(1,1) to L(0,1) due to reduced friction contact among individual wires. This change of guided waves modes in response to damage variations, associated with the transmitted ultrasonic energy, was identified and discussed as potential mean of damage monitoring.
Implementation of a force controller based on fuzzy rule emulate networks for soft contact with an object with unknown mechanical properties, Flexible Automation and Intelligent Manufacturi ng (FAIM), 2014.
@inproceedings{Carreon2014,
title = {Implementation of a force controller based on fuzzy rule emulate networks for soft contact with an object with unknown mechanical properties},
author = {Carreon, Augusto and Treesatayapun, Chidentree and Baltazar, Arturo},
url = {https://www.researchgate.net/publication/300916120_Implementation_of_a_force_controller_based_on_fuzzy_rule_emulate_networks_for_soft_contact_with_an_object_with_unknown_mechanical_properties},
year = {2014},
date = {2014-00-00},
booktitle = {Implementation of a force controller based on fuzzy rule emulate networks for soft contact with an object with unknown mechanical properties},
publisher = {Flexible Automation and Intelligent Manufacturi ng (FAIM)},
abstract = {in this article, a novel force control system for soft contact with an object of unknown mechanical properties is proposed by using an ultrasonic sensor implemented in a 3 DOF manipulator robotic system. The emphasis is on the development of a control system to allow soft contact with an object of nonlinear elastic contact properties. In this work a Multi-input Fuzzy Rules Emulate Network (MiFREN) scheme controller with adaptation is developed to regulate the contact force. We propose the use of an ultrasonic sensor in conjunction with a signal conditioning for force based on a parallel-distributed-model as well as the Hertzian model, and considering the transmission and reflection of ultrasonic wave properties. The IF-THEN rules for the MiFREN control are defined taking into account the human knowledge of a physical system and a stability analysis is developed by the Lyapunov method. The experimental results demonstrate that the system is able to find a stable first contact force and moreover the proposed controller is capable of controlling the contact force for both regulation and tracking tasks.
Implementation of a force controller based on fuzzy rule emulate networks for soft contact with an object with unknown mechanical properties (PDF Download Available). Available from: https://www.researchgate.net/publication/300916120_Implementation_of_a_force_controller_based_on_fuzzy_rule_emulate_networks_for_soft_contact_with_an_object_with_unknown_mechanical_properties [accessed Jun 16, 2017].},
keywords = {fuzzy rule, implementation},
pubstate = {published},
tppubtype = {inproceedings}
}
in this article, a novel force control system for soft contact with an object of unknown mechanical properties is proposed by using an ultrasonic sensor implemented in a 3 DOF manipulator robotic system. The emphasis is on the development of a control system to allow soft contact with an object of nonlinear elastic contact properties. In this work a Multi-input Fuzzy Rules Emulate Network (MiFREN) scheme controller with adaptation is developed to regulate the contact force. We propose the use of an ultrasonic sensor in conjunction with a signal conditioning for force based on a parallel-distributed-model as well as the Hertzian model, and considering the transmission and reflection of ultrasonic wave properties. The IF-THEN rules for the MiFREN control are defined taking into account the human knowledge of a physical system and a stability analysis is developed by the Lyapunov method. The experimental results demonstrate that the system is able to find a stable first contact force and moreover the proposed controller is capable of controlling the contact force for both regulation and tracking tasks.
Implementation of a force controller based on fuzzy rule emulate networks for soft contact with an object with unknown mechanical properties (PDF Download Available). Available from: https://www.researchgate.net/publication/300916120_Implementation_of_a_force_controller_based_on_fuzzy_rule_emulate_networks_for_soft_contact_with_an_object_with_unknown_mechanical_properties [accessed Jun 16, 2017].
