Optimized automatic system to obtain ultrasonic radiation patterns

Due to the need to know and modify the radiation pattern of the ultrasonic sensors, to suit them to a particular application, in this paper is presented an automated measure system to obtain the radiation pattern for ultrasonic sensors in air. The system allows to obtain the radiation pattern in different conditions, for example for checking the characteristics of the ultrasonic sensors provided by the manufacturer, or for obtaining the modifications in the radiation pattern when a mechanical element is coupled to the ultrasonic sensor. In addition, the system has been improved by shortening the measurement time and decreasing the volume of data needed to carry out a measure. Furthermore, due to the fact of implementing the system inside a climatic chamber, the system allows to analyze the influence of environmental factors such as temperature and humidity, plus an evaluation of the degradation behaviour of the ultrasonic sensors in air under conditions of high temperature and humidity. At the end of the paper, two measurements have been done and the results have been compared with the characteristics of the radiation pattern provided by the manufacturer. Finally, a robust measurement system is presented, designed to find the modifications in the radiation pattern of an ultrasonic sensor when it is coupled to a mechanical element

3D point cloud registration based on a purpose-designed similarity measure

This article introduces a novel approach for finding a rigid transformation that coarsely aligns two 3D point clouds. The algorithm performs an iterative comparison between 2D descriptors by using a purpose-designed similarity measure in order to find correspondences between two 3D point clouds sensed from different positions of a free-form object. The descriptors (named with the acronym CIRCON) represent an ordered set of radial contours that are extracted around an interest-point within the point cloud. The search for correspondences is done iteratively, following a cell distribution that allows the algorithm to converge toward a candidate point. Using a single correspondence an initial estimation of the Euclidean transformation is computed and later refined by means of a multiresolution approach. This coarse alignment algorithm can be used for 3D modeling and object manipulation tasks such as "Bin Picking" when free-form objects are partially occluded or present symmetries

Modelling, simulation and control of pedestrian avoidance maneuver for an urban electric vehicle

The mathematical model of an electric vehicle, as well as the control system for avoiding pedestrians in urban traffic is described. The vehicle is modeled as a continuous system consisting of several subsystems. In addition, a set of sensors and actuators along with a two-level discrete control system are modeled. Based on this model, a pedestrian avoidance maneuver for typical speeds in city traffic is simulated. When the sensory system detects a pedestrian in the vehicle's path, the decision system calculates its trajectory. Using this information, the speed and/or direction that the vehicle must take in order to avoid the accident are estimated. These values are sent to the low-level controllers of the accelerator/brake and steering, which generate the signals to be applied to such systems to achieve the desired trajectory and speed.This work is funded by the Spanish Ministry of Economy and Competitiveness, projects “Automatización y Control Inteligente de Vehículos Eléctricos Urbanos” (ACIVEU, DPI2012-36959) and “Assisted Navigation through Natural Language” (NAVEGASE, DPI2014-53525-C3-1-R)

Aparato, procedimiento y sistema para el registro ambulatorio y el análisis de la presión intracraneal, así como para la detección automática de patologías asociadas.

Sistema autónomo para el registro ambulatorio de la presión intracraneal de un paciente, que comprende un sensor de presión intracraneal que transmite la señal de presión intracraneal a un aparato portátil que puede controlar la captura de la señal y almacenarla. El aparato portátil comprende un dispositivo de memoria para almacenar las muestras de presión intracraneal, un microcontrolador para controlar los parámetros de muestreo de la presión intracraneal y unos medios para programar dicho microcontrolador. Dichos parámetros se optimizan en base a resultados experimentales, de acuerdo con una resolución preestablecida, para minimizar el consumo de energía del sistema. El sistema comprende un PC mediante el cual se pueden procesar las muestras de presión intracraneal almacenadas en el dispositivo de memoria del aparato portátil, y el cual puede proporcionar una ayuda al diagnóstico médico de patologías asociadas a estos registros.Solicitud: 200900097 (09.01.2009)Nº Pub. de Solicitud: ES2379720A1 (03.05.2012)Nº de Patente: ES2379720B1 (01.07.2013

Monovision-based vehicle detection, distance and relative speed measurement in urban traffic

This study presents a monovision-based system for on-road vehicle detection and computation of distance and relative speed in urban traffic. Many works have dealt with monovision vehicle detection, but only a few of them provide the distance to the vehicle which is essential for the control of an intelligent transportation system. The system proposed integrates a single camera reducing the monetary cost of stereovision and RADAR-based technologies. The algorithm is divided in three major stages. For vehicle detection, the authors use a combination of two features: the shadow underneath the vehicle and horizontal edges. They propose a new method for shadow thresholding based on the grey-scale histogram assessment of a region of interest on the road. In the second and third stages, the vehicle hypothesis verification and the distance are obtained by means of its number plate whose dimensions and shape are standardised in each country. The analysis of consecutive frames is employed to calculate the relative speed of the vehicle detected. Experimental results showed excellent performance in both vehicle and number plate detections and in the distance measurement, in terms of accuracy and robustness in complex traffic scenarios and under different lighting conditions

Contribución al estudio de sistemas ultrasónicos y su aplicación a la seguridad activa en vehículos inteligentes

RESUMEN: Se pretende analizar la posibilidad de utilizar un sistema ultrasónico como elemento sensor para el control inteligente del vehículo en tráfico urbano, es decir, a bajas velocidades y distancias cortas entre vehículos. Está comprobado que la mayoría de los accidentes de circulación tienen lugar en estas condiciones. Los sensores ultrasónicos requieren de una electrónica más sencilla y son más baratos que otros tipos como los basados en radar o láser. Para ello es necesario estudiar la influencia de los factores meteorológicos en la propagación de ultrasonidos en el aire. También se deben analizar diferentes técnicas que permitan mejorar el rendimiento de los sensores ultrasónicos conformando su diagrama de radiación, como la incorporación de bocinas.ABSTRACT: We analyze the possibility of using an ultrasonic sensor for intelligent control of the vehicle in urban traffic, i.e., at low speeds and short distances. It is proven that most accidents occur in these conditions. Ultrasonic sensors require electronics that are simpler and cheaper than other types as those based on radar or laser. This requires studying the influence of meteorological conditions in the propagation of ultrasound in air. It also should discuss different techniques to improve the performance of ultrasonic sensors, as the inclusion of horns

Automática (G739). Febrero 2017

Grado en Ingeniería Mecánic

Automática (G739). Septiembre 2020

Grado en Ingeniería Mecánic

Automática (G739). Septiembre 2017

Grado en Ingeniería Mecánic

Detection and Identification of Pedestrians and Vehicles Using Radar for Driving Assistance

[Resumen] El desarrollo de sistemas de ayuda a la conducción, ADAS (Advanced Driver Assistance Systems), ha dado lugar a un significativo descenso en el número de accidentes. Los fabricantes de automóviles han desarrollado sistemas para facilitar la labor al conductor en circulación a altas velocidades o avisar al conductor de situaciones de inminente peligro, bien mediante señales visuales o sonoras. Estos sistemas presentan el inconveniente de la dependencia de la respuesta al estímulo por parte del conductor. El objetivo básico del trabajo ha consistido en la detección automática, mediante técnicas de radar y redes neuronales, de cuerpos que se encuentren delante de un vehículo, tanto vehículos como peatones, para aumentar la seguridad. Puede señalarse que aproximadamente el 85% de las mediciones realizadas son identificadas correctamente por la red neuronal. La información será utilizada para avisar al conductor o para la actuación automática sobre el freno y la dirección del vehículo, para evitar la colisión.[Abstract] The development of systems for driving assistance, ADAS (Advanced Driver Assistance Systems), has led to a significant decrease in the number of accidents. Car manufacturers have developed systems to facilitate the work to the driver in circulation at high speeds or warn the driver of situations of imminent danger, either by visual or audible signals. These systems have the drawback of the dependence of the response to the stimulus by the driver. The basic objective of the work has been the automatic detection, by radar techniques and neural networks, of bodies that are in front of a vehicle, both vehicles and pedestrians, to increase safety. It can be noted that approximately 85% of the measurements made are correctly identified by the neural network. The information will be used to warn the driver or for the automatic action on the brake and the direction of the vehicle, to avoid the collisionMinisterio de Economía y Competitividad; DPI-3695