198 research outputs found
Ultra Wideband Indoor Navigation System
Typical indoor environments contain multiple walls and obstacles consisting of different materials. As a result, current narrowband radio frequency (RF) indoor navigation systems cannot satisfy the challenging demands for most indoor applications. The RF ultra wideband (UWB) system is a promising technology for indoor localisation owing to its high bandwidth that permits mitigation of the multipath identification problem. This work proposes a novel UWB navigation system that permits accurate mobile robot (MR) navigation in indoor environments. The navigation system is composed of two sub-systems: the localisation system and the MR control system. The main contributions of this work are focused on estimation algorithm for localisation, digital implementation of transmitter and receiver and integration of both sub-systems that enable autonomous robot navigation. For sub-systems performance evaluation, statics and dynamics experiments were carried out which demonstrated that the proposed system reached an accuracy that outperforms traditional sensors technologies used in robot navigation, such as odometer and sonar.Fil: Segura M.. Universidad Nacional de San Juan; ArgentinaFil: Mut, Vicente Antonio. Universidad Nacional de San Juan; Argentina. Consejo Nacional de Investigaciones CientÃficas y Técnicas; ArgentinaFil: Sisterna C.. Universidad Nacional de San Juan; Argentin
Method to Estimate Human Inattention in Teleoperation of Mobile Robots
In teleoperation of mobile robots the operator is remotely located. As a result, generally the human perception of the remote environment is distorted affecting the mission negatively. Visual information can be degraded because of video images bandwith, time lags, frame rates, point of view and motion effects among other reasons. Although many researchers have proposed a variety of methods for measuring perception, just a few can be used in control closed loop systems. This paper aims to provide a novel metric to the human visual inattention upon risk for a remotely navigated mobile robot. We present both qualitative and quantitative guidelines for designing the metric in a teleoperation of a mobile robot. The method allows to incorporate the metric in a control closed loop system, and task consists in guiding the robot from an initial point to a final one as quick as possible, considering the constraint of avoiding collisions. Furthermore, a haptic cue based on the metric is proposed in order to help the human to avoid collisions. A system stability analysis considering time varying delays is proposed. Additionally, we present a human in the loop experiment of a teleoperation of a 3D mobile robot simulator in order to remark the advantages of using human factors in the controller.Fil: Penizzotto Bacha, Franco Victor. Consejo Nacional de Investigaciones CientÃficas y Técnicas. Centro CientÃfico Tecnológico San Juan. Instituto de Automática; ArgentinaFil: Mut, Vicente Antonio. Consejo Nacional de Investigaciones CientÃficas y Técnicas. Centro CientÃfico Tecnológico San Juan. Instituto de Automática; ArgentinaFil: Slawiñski, Emanuel. Consejo Nacional de Investigaciones CientÃficas y Técnicas. Centro CientÃfico Tecnológico San Juan. Instituto de Automática; Argentin
Vision-based interface applied to assistive robots
This paper presents two vision-based interfaces for disabled people to command a mobile robot for personal assistance. The developed interfaces can be subdivided according to the algorithm of image processing implemented for the detection and tracking of two different body regions. The first interface detects and tracks movements of the user's head, and these movements are transformed into linear and angular velocities in order to command a mobile robot. The second interface detects and tracks movements of the user's hand, and these movements are similarly transformed. In addition, this paper also presents the control laws for the robot. The experimental results demonstrate good performance and balance between complexity and feasibility for real-time applications.Fil: Pérez Berenguer, MarÃa Elisa. Universidad Nacional de San Juan. Facultad de IngenierÃa. Departamento de Electrónica y Automática. Gabinete de TecnologÃa Médica; Argentina. Consejo Nacional de Investigaciones CientÃficas y Técnicas; ArgentinaFil: Soria, Carlos Miguel. Consejo Nacional de Investigaciones CientÃficas y Técnicas. Centro CientÃfico Tecnológico Conicet - San Juan. Instituto de Automática. Universidad Nacional de San Juan. Facultad de IngenierÃa. Instituto de Automática; ArgentinaFil: López Celani, Natalia Martina. Universidad Nacional de San Juan. Facultad de IngenierÃa. Departamento de Electrónica y Automática. Gabinete de TecnologÃa Médica; Argentina. Consejo Nacional de Investigaciones CientÃficas y Técnicas; ArgentinaFil: Nasisi, Oscar Herminio. Universidad Nacional de San Juan. Facultad de IngenierÃa. Instituto de Automática; ArgentinaFil: Mut, Vicente Antonio. Consejo Nacional de Investigaciones CientÃficas y Técnicas. Centro CientÃfico Tecnológico Conicet - San Juan. Instituto de Automática. Universidad Nacional de San Juan. Facultad de IngenierÃa. Instituto de Automática; Argentin
Stable Bilateral Teleoperation Control Method for Biped Robots with Time-Varying Delays
This document proposes a control scheme applied to delayed bilateral teleoperation of the forward and turn speed of a biped robot against asymmetric and time-varying delays. This biped robot is modeled as a hybrid dynamic system because it behaves as a continuous system when the leg moves forward and discrete when the foot touches the ground generating an impulsive response. It is proposed to vary online the damping according to the time delay present in the communication channel, and the walking cycle time using an optimization criterion, to decrease the teleoperation system errors. To accomplish this, a three-phase cascade calibration process is used, and their benefits are evidenced in a comparative simulation study. The first phase is an offline calibration of the inverse dynamic compensation and also the parameters of the bilateral controller. The second phase guarantees the bilateral coordination of the delayed teleoperation system, using the Lyapunov–Krasovskii stability theory, by changing the leader damping and the equivalent follower damping together. The third phase assures a stable walk of the hybrid dynamics by controlling the walking cycle time and the real damping to move the eigenvalues of the Poincaré map, numerically computed, to stable limit cycles and link this result with an equivalent continuous system to join both phases. Additionally, a fictitious force was implemented to detect and avoid possible collisions with obstacles. Finally, an intercontinental teleoperation experiment of an NAO robot via the Internet including force and visual feedback is shown
Comprehensive analysis of PM20D1 QTL in Alzheimer’s disease
Background Alzheimer’s disease (AD) is a complex disorder caused by a combination of genetic and non-genetic risk factors. In addition, an increasing evidence suggests that epigenetic mechanisms also accompany AD. Genetic and epigenetic factors are not independent, but multiple loci show genetic-epigenetic interactions, the so-called quantitative trait loci (QTLs). Recently, we identified the first QTL association with AD, namely Peptidase M20 Domain Containing 1 (PM20D1). We observed that PM20D1 DNA methylation, RNA expression, and genetic background are correlated and, in turn, associated with AD. We provided mechanistic insights for these correlations and had shown that by genetically increasing and decreasing PM20D1 levels, AD-related pathologies were decreased and accelerated, respectively. However, since the PM20D1 QTL region encompasses also other genes, namely Nuclear Casein Kinase and Cyclin Dependent Kinase Substrate 1 (NUCKS1); RAB7, member RAS oncogene family-like 1 (RAB7L1); and Solute Carrier Family 41 Member 1 (SLC41A1), we investigated whether these genes might also contribute to the described AD association. Results Here, we report a comprehensive analysis of these QTL genes using a repertoire of in silico methods as well as in vivo and in vitro experimental approaches. First, we analyzed publicly available databases to pinpoint the major QTL correlations. Then, we validated these correlations using a well-characterized set of samples and locus-specific approaches—i.e., Sanger sequencing for the genotype, cloning/sequencing and pyrosequencing for the DNA methylation, and allele-specific and real-time PCR for the RNA expression. Finally, we defined the functional relevance of the observed alterations in the context of AD in vitro. Using this approach, we show that only PM20D1 DNA methylation and expression are significantly correlated with the AD-risk associated background. We find that the expression of SLC41A1 and PM20D1—but not NUCKS1 and RAB7L1—is increased in mouse models and human samples of AD, respectively. However, SLC41A1 and PM20D1 are differentially regulated by AD-related stressors, with only PM20D1 being upregulated by amyloid-β and reactive oxygen species, and with only PM20D1 being neuroprotective when overexpressed in cell and primary cultures. Conclusions Our findings reinforce PM20D1 as the most likely gene responsible of the previously reported PM20D1 QTL association with AD
PD-like controller with impedance for delayed bilateral teleoperation of mobile robots
This paper proposes a control scheme applied to the delayed bilateral teleoperation of mobile robots with force feedback in face of asymmetric and time-varying delays. The scheme is managed by a velocity PD-like control plus impedance and a force feedback based on damping and synchronization error. A fictitious force, depending on the robot motion and its environment, is used to avoid possible collisions. In addition, the stability of the system is analyzed from which simple conditions for the control parameters are established in order to assure stability. Finally, the performance of the delayed teleoperation system is shown through experiments where a human operator drives a mobile robot.Fil: Slawiñski, Emanuel. Consejo Nacional de Investigaciones CientÃficas y Técnicas. Centro CientÃfico Tecnológico San Juan. Instituto de Automática; ArgentinaFil: GarcÃa, Sebastián Ernesto. Consejo Nacional de Investigaciones CientÃficas y Técnicas. Centro CientÃfico Tecnológico San Juan. Instituto de Automática; ArgentinaFil: Salinas, Lucio Rafael. Consejo Nacional de Investigaciones CientÃficas y Técnicas. Centro CientÃfico Tecnológico San Juan. Instituto de Automática; ArgentinaFil: Mut, Vicente Antonio. Consejo Nacional de Investigaciones CientÃficas y Técnicas. Centro CientÃfico Tecnológico San Juan. Instituto de Automática; Argentin
TelemetrÃa agrÃcola: un acercamiento hacia las nuevas tecnologÃas disponibles en riego de precisión
Los sistemas de telemetrÃa permiten la monitorización y control remoto de procesos a grandes distancias; la implementación en la agricultura es reciente y demuestra importantes ventajas. En el trabajo se presenta el desarrollo de un sistema de TelemetrÃa AgrÃcola conformado por de estaciones de medición (fijas y móviles) que se instalan dentro de la zona cultivada; en combinación con de una serie de módulos informáticos encargados de procesar los datos de campo (estación base), el sistema permite disponer de información en tiempo real sobre la evolución del cultivo, la gestión del riego y condiciones del clima. Se presenta una descripción de cada componente del sistema para el cual se integraron tecnologÃas en electrónica, comunicación, informática robótica y control automático. El desarrollo incluyó el diseño de un entorno visual para que los usuarios consulten la información y gestionen las operaciones del riego de manera precisa en base a la demanda hÃdrica del cultivo, entre otros requerimientos. Finalmente se presenta un ensayo sobre una parcela de tomate en la que se aplicaron tres tratamientos de riego diferenciados.Sociedad Argentina de Informática e Investigación Operativ
TelemetrÃa agrÃcola: un acercamiento hacia las nuevas tecnologÃas disponibles en riego de precisión
Los sistemas de telemetrÃa permiten la monitorización y control remoto de procesos a grandes distancias; la implementación en la agricultura es reciente y demuestra importantes ventajas. En el trabajo se presenta el desarrollo de un sistema de TelemetrÃa AgrÃcola conformado por de estaciones de medición (fijas y móviles) que se instalan dentro de la zona cultivada; en combinación con de una serie de módulos informáticos encargados de procesar los datos de campo (estación base), el sistema permite disponer de información en tiempo real sobre la evolución del cultivo, la gestión del riego y condiciones del clima. Se presenta una descripción de cada componente del sistema para el cual se integraron tecnologÃas en electrónica, comunicación, informática robótica y control automático. El desarrollo incluyó el diseño de un entorno visual para que los usuarios consulten la información y gestionen las operaciones del riego de manera precisa en base a la demanda hÃdrica del cultivo, entre otros requerimientos. Finalmente se presenta un ensayo sobre una parcela de tomate en la que se aplicaron tres tratamientos de riego diferenciados.Sociedad Argentina de Informática e Investigación Operativ
A linear-interpolation-based controller design for trajectory tracking of mobile robots
This work presents a novel linear interpolation based methodology to design control algorithms for the trajectory tracking of mobile robotic systems. Particularly, a typical nonlinear multivariable system-a mobile robot-is analysed. The methodology is simple and can be applied to the design of a large class of control systems. Simulation and experimental results are presented and discussed, demonstrating the good performance of the proposed methodology.Fil: Scaglia, Gustavo Juan Eduardo. Universidad Nacional de San Juan. Facultad de IngenierÃa. Instituto de IngenierÃa QuÃmica; Argentina. Consejo Nacional de Investigaciones CientÃficas y Técnicas; Argentina. Universidad Nacional de San Juan. Facultad de IngenierÃa. Instituto de Automática; ArgentinaFil: Rosales, Andrés. Universidad Nacional de San Juan. Facultad de IngenierÃa. Instituto de Automática; ArgentinaFil: Quintero, Lucia. Universidad Nacional de San Juan. Facultad de IngenierÃa. Instituto de Automática; ArgentinaFil: Mut, Vicente. Universidad Nacional de San Juan. Facultad de IngenierÃa. Instituto de Automática; ArgentinaFil: Agarwal, Ravi. Florida Institute of Technology; Estados Unido
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