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International Conference on Indoor Positioning and Indoor Navigation (IPIN)

作者： Fernando Seco Antonio R. Jiménez Francisco Zampella Consejo Superior de Investigaciones Científicas (CSIC)-UPM Centre for Automation and Robotics Madrid Spain

In personal indoor guidance and navigation applications, it is desirable to determine both the user's position and spatial orientation, since this enables to provide him with directions in a more natural way. The common method for estimation of orientation uses the magnetic compass included in numerous portable devices; this approach becomes unreliable when the device's own orientation relative to the user is unknown, or if the environment contains metallic structures which disturb the magnetic field. In this work we propose an alternative approach for estimation of personal position and orientation which requires no additional sensors and is based solely in the attenuation of radiofrequency signal strength (RSS) introduced by the user's own body. The physical system consists in a set of emitting RF nodes located at known positions in the environment, and two RF receivers placed in the front and back parts of the user's body (alternatively, a single receiver with two antennas). We show how the position of the user can be inferred from the average received signal strength, while his orientation is estimated from the difference of signal strengths from the two receivers, by adapting two commonly used techniques in indoor localization: least-squares minimization and Bayesian filters. We have validated experimentally both techniques with an RFID-based localization system arranged in a typical building, showing that orientation can be determined with a mean error of 0.3 radians, sufficient for most applications.

关键词： Radio frequency Estimation Attenuation Fingerprint recognition Magnetic devices Receiving antennas

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Robust indoor positioning fusing PDR and RF technologies: The RFID and UWB case

Robust indoor positioning fusing PDR and RF technologies: Th...

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International Conference on Indoor Positioning and Indoor Navigation (IPIN)

作者： Francisco Zampella Antonio R. Jiménez R. Fernando Seco Consejo Superior de Investigaciones Científicas (CSIC)-UPM Centre for Automation and Robotics Madrid Spain

Indoor positioning is usually based on individual technologies that provide estimates of the trajectory of the person, or measures the ranges or angles between the user and known positions. Each technique has its advantages and problems, and a common way to overcome the drawbacks of single-technology solutions is to fuse the information from several system, but due to their non linear measurements, there is no optimal linear solution. We propose the use of a particle filter to fuse foot mounted inertial measurements with any additional Radio Frequency (RF) measurement. The information fusion is achieved propagating the position of the particles using the relative step displacements obtained from foot mounted Pedestrian Dead Reckoning (PDR), and updating the weights of the particles according to the RF measurements. In our experiments the inertial unit was located in the foot of the user, and the RF system consisted in a Radio Frequency Identification (RFID) receiver in the waist, and an Ultra Wide band (UWB) tag in the chest, but the scheme can be used in any sensor configuration. As the UWB measurements have a significant amount of outliers due to non line of sight conditions generated by the position of the tag in the body, received reflections, etc., we propose a new outlier rejection algorithm based on the compatibility of groups of measurements. The fusion was tested evaluating the inclusion of each of the RF systems and varying the number RFID tags used. The proposed method is able to locate a person with less than 2 m of error (for 90 % of the obtained estimations) in the studied trajectory. This particle filter scheme offers robust indoor positioning with 100 % availability and smooth trajectory estimation thanks to the PDR and limited error due to the RF measurements.

关键词： Position measurement Atmospheric measurements Particle measurements Measurement uncertainty Loss measurement Displacement measurement Noise measurement

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Light-matching: A new signal of opportunity for pedestrian indoor navigation

Light-matching: A new signal of opportunity for pedestrian i...

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International Conference on Indoor Positioning and Indoor Navigation (IPIN)

作者： A.R. Jiménez F. Zampella F. Seco Consejo Superior de Investigaciones Científicas (CSIC)-UPM Centre for Automation and Robotics (CAR) Madrid Spain

This paper presents a new indoor location concept named Light-matching which uses the perceived gradient in the illumination from unmodified indoor lights to achieve accurate physical location. The proposed method does not require any illumination calibration, just the pre-storage of the position and size of all lights in a building, irrespective of their current on/off state. The Light-matching method also requires the estimation of the relative displacement and orientation change of a person which is done by inertial Pedestrian Dead-Reckoning (PDR). Even from an initially unknown location and orientation, whenever the person passes below a switched-on light spot, the location likelihood is iteratively updated until it potentially converges to an unimodal probability density function. The time to converge to an unimodal position hypothesis depends on the number of lights detected and the asymmetries/irregularities of light distributions. The light-matching technique can be used alone or in cooperation with other signals of opportunity (WiFi, Magnetometers or Map-matching) to obtain a continuous high accuracy indoor localization system. This paper presents the basic description of the light-matching concept, the implementation details using a particle filter, and the evaluation of the method by simulation. The performance of the integrated solution can achieve a localization error lower than 1 m in most of the cases.

关键词： Lighting Estimation Atmospheric measurements Particle measurements Standards Switches Probability density function

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Stability Analysis of Teleoperation System by State Convergence with Variable Time Delay

Stability Analysis of Teleoperation System by State Converge...

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American Control Conference

作者： Julio C. Tafur Cecilia García Rafael Aracil Roque Saltaren Pontificia Universidad Catolica del Peru. Departamento de Ingenieria. Seccion Electricidad y Electronica. Av. Universitaria No. 1801 San Miguel Lima-32 PERU Centre for Automation and Robotics UPM-CSIC Madrid SPAIN Centre for Automation and Robotics UPM- CSIC Madrid SPAIN

ISBN: (纸本)9781479901777

We propose a novel control scheme for bilateral teleoperation of n degree-of-freedom (DOF) nonlinear robotic systems with time-varying communication delay. A major contribution from this work lies in the demonstration that the structure of a state convergence algorithm can be also applied to nth-order nonlinear teleoperation systems. By choosing a Lyapunov Krasovskii functional, we show that the local-remote teleoperation system is asymptotically stable. The time delay of communication channel is assumed to be unknown and randomly time varying, but the upper bounds of the delay interval and the derivative of the delay are assumed to be known.

关键词： remote operation delay interval Stability analysis time varying Converge Upper bound

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Corrigendum to “Discernment of bee pollen loads using computer vision and one-class classification techniques” [J. Food Eng. 112 (1–2) (2012) 50–59]

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Journal of Food Engineering 2014年 138卷 53-53页

作者： Manuel Chica Pascual Campoy Inspiralia Tecnologías Avanzadas Estrada 10 28034 Madrid Spain European Centre for Soft Computing Gonzalo Gutiérrez Quirós 33600 Mieres Asturias Spain Universidad Politécnica de Madrid Centre for Automation and Robotics UPM – CSIC José Gutiérrez Abascal 2 28006 Madrid Spain

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Benefits and drawbacks of MRF knee damping in legged robots

Benefits and drawbacks of MRF knee damping in legged robots

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15th International Conference on Climbing and Walking Robots and the Support Technologies for Mobile Machines, CLAWAR 2012

作者： Muñoz, G. Cestari, M. Arevalo, J.C. Sanz-Merodio, D. Garcia, E. Centre for Automation and Robotics CSIC La Poveda UPM 28500 Madrid Spain

ISBN: (纸本)9789814415941

In order to create efficient legged robots it is needed to care about energy consumption. During motion, energy is used in two different ways: positive energy to generate movement, and negative energy to brake movement. The use of passive components to dissipate the energy by friction could be a possible solution to avoid braking with active elements. This paper deals with the problem of determining experimentally the benefits of damping the knee by absorbing negative energy in MRF dampers, against actively braking using the actuators. Copyright © 2012 by World Scientific Publishing Co. Pte. Ltd.

关键词： Damping

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Impedance control for a bioinspired underactuated LEG

Impedance control for a bioinspired underactuated LEG

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15th International Conference on Climbing and Walking Robots and the Support Technologies for Mobile Machines, CLAWAR 2012

作者： Arevalo, Juan Carlos Cestari, Manuel Sanz-Merodio, Daniel Garcia, Elena Centre for Automation and Robotics CSIC UPM Carretera Campo Real Arganda del Rey 28500 Spain

ISBN: (纸本)9789814415941

Bioinspired legged robots are a good option for field missions over complex terrain such as extraterrestrial landscape, disaster scenarios, etc. For these ap- plications robots should exhibit good performance in terms of mobility, payload and endurance. In this work a control law to exploit the HADE leg dynamic features in order to save electrical energy by reducing the required mechanical work is presented. This control law is a force based impedance control scheme that considers the fact that the prototype is an underactuated mechanism. An analysis on the energy saving capabilities of the system, based on spring stiffness is theoretically performed and experimentally validated. Copyright © 2012 by World Scientific Publishing Co. Pte. Ltd.

关键词： Energy conservation

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Trajectory generator for autonomous vehicles in urban environments

Trajectory generator for autonomous vehicles in urban enviro...

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IEEE International Conference on robotics and automation (ICRA)

作者： Joshué Pérez Jorge Godoy Jorge Villagrá Enrique Onieva INRIA research center Paris ROCQUENCOURT France Industrial Computer Science Department Centre of Automation and Robotics (CAR) Consejo Superiorde Investigaciones Cientficas Universidad Politecnica de Madrid Madrid Spain Industrial Computer Science Department UPM-CSIC Madrid Spain Institute of Technology (DeustoTech) University of Deusto Bilbao Spain

Nowadays, some developments in the vehicle industry permit a safe and comfortable driving. However, several manufactures and research groups are still working in the improvement of the control strategies and path smoothing algorithms. In this paper, a new trajectory generation approach for autonomous vehicles in urban scenarios, considering parametric equations, is proposed. An algorithm that considers Bezier curves and circumference parametric equations for a real vehicle, specifically in roundabout and urban intersections is presented. This approach is generated in real time and can be adapted to dynamic changes in the route. A smooth trajectory generator computationally efficient and easily implementable is proposed. Moreover, this new trajectory generator reduces the control actions, generated with to a fuzzy controller. Some trials have been performed in an urban circuit with promising performance.

关键词： Mobile robots Wheels

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Multi-path planning based on a NSGA-II for a fleet of robots to work on agricultural tasks

Multi-path planning based on a NSGA-II for a fleet of robots...

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Congress on Evolutionary Computation

作者： Jesus Conesa-Muñoz Angela Ribeiro Dionisio Andujar Cesar Fernandez-Quintanilla Jose Dorado Centre for Automation and Robotics CSIC-UPM Madrid Spain Institute of Agricultural Science CSIC Madrid Spain

In many situations, using multiple robots in the same environment is a good strategy to handle tasks that are too complex or even too expensive for a single robot. One of these situations is the automation of tasks in the agricultural environment. In this context, one of the main problems consists of determining the best routes (multi-path plan) for the robots to minimise cost, while ensuring a fully completed treatment, i.e., the whole field is covered. The cost can be expressed by a function that considers the most relevant features of each robot in the fleet, for example, in a spray weed treatment, the tank capacity, the number of turns required or the time spent in the whole treatment. This multi-path planning problem can be expressed as a bi-objective problem. In particular, in this paper, two different objectives are taken into account: the cost in time and the cost in money. This formulation allows the analysis of situations in which it is important to distribute the robots to reduce the time of the treatment independently of the money spent and of situations where it is important to reduce the spent money independently of the time consumed. A Non-dominated Sorting Genetic Algorithm II (NSGA-II) is proposed for solving the multi-objective problem. The proposed approach has proven to offer good results in multiple situations dealing with different fields and robots with diverse features. Moreover, the results obtained show that it is possible to determine solutions very close to the optimum of each objective, even simultaneously.

关键词： Agriculture Robot kinematics Fuels Vectors Vehicles Turning

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A constraint approach for UWB and PDR fusion

A constraint approach for UWB and PDR fusion

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International Conference on Indoor Positioning and Indoor Navigation (IPIN)

作者： Francisco Zampella Alessio De Angelis Isaac Skog Dave Zachariah Antonio Jiménez Centre for Automation and Robotics (CAR) Consejo Superior de Investigaciones Cientificas (CSIC) UPM Madrid Spain Signal Processing Laboratory ACCESS Linnaeus Centre KTH Royal Institute of Technology Stockholm Sweden

Pedestrian Dead-Reckoning (PDR) and Radio Frequency (RF) ranging/positioning are complementary techniques for position estimation but they usually locate different points in the body (RF in the head/hand and PDR in the foot). We propose to fuse the information from both navigation points using a constraint filter with an upper bound in the distance between the estimated positions of both sensors.

关键词： Xenon Yttrium

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