Shadow detection in still road images using chrominance properties of shadows and spectral power distribution of the illumination

A well-known challenge in vision-based driver assistance systems is cast shadows on the road, which makes fundamental tasks such as road and lane detections difficult. In as much as shadow detection relies on shadow features, in this paper, we propose a set of new chrominance properties of shadows based on the skylight and sunlight contributions to the road surface chromaticity. Six constraints on shadow and non-shadowed regions are derived from these properties. The chrominance properties and the associated constraints are used as shadow features in an effective shadow detection method intended to be integrated on an onboard road detection system where the identification of cast shadows on the road is a determinant stage. Onboard systems deal with still outdoor images; thus, the approach focuses on distinguishing shadow boundaries from material changes by considering two illumination sources: sky and sun. A non-shadowed road region is illuminated by both skylight and sunlight, whereas a shadowed one is illuminated by skylight only; thus, their chromaticity varies. The shadow edge detection strategy consists of the identification of image edges separating shadowed and non-shadowed road regions. The classification is achieved by verifying whether the pixel chrominance values of regions on both sides of the image edges satisfy the six constraints. Experiments on real traffc scenes demonstrated the effectiveness of our shadow detection system in detecting shadow edges on the road and material-change edges, outperforming previous shadow detection methods based on physical features, and showing the high potential of the new chrominance properties

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

Shadow-based vehicle detection in urban traffic

Vehicle detection is a fundamental task in Forward Collision Avoiding Systems (FACS). Generally, vision-based vehicle detection methods consist of two stages: hypotheses generation and hypotheses verification. In this paper, we focus on the former, presenting a feature-based method for on-road vehicle detection in urban traffic. Hypotheses for vehicle candidates are generated according to the shadow under the vehicles by comparing pixel properties across the vertical intensity gradients caused by shadows on the road, and followed by intensity thresholding and morphological discrimination. Unlike methods that identify the shadow under a vehicle as a road region with intensity smaller than a coarse lower bound of the intensity for road, the thresholding strategy we propose determines a coarse upper bound of the intensity for shadow which reduces false positives rates. The experimental results are promising in terms of detection performance and robustness in day time under different weather conditions and cluttered scenarios to enable validation for the first stage of a complete FACS.This work is funded by the Spanish Ministry of Economy and Competitiveness (Project: DPI2012-36959)

Working together: a review on safe human-robot collaboration in industrial environments

After many years of rigid conventional procedures of production, industrial manufacturing is going through a process of change toward flexible and intelligent manufacturing, the so-called Industry 4.0. In this paper, human-robot collaboration has an important role in smart factories since it contributes to the achievement of higher productivity and greater efficiency. However, this evolution means breaking with the established safety procedures as the separation of workspaces between robot and human is removed. These changes are reflected in safety standards related to industrial robotics since the last decade, and have led to the development of a wide field of research focusing on the prevention of human-robot impacts and/or the minimization of related risks or their consequences. This paper presents a review of the main safety systems that have been proposed and applied in industrial robotic environments that contribute to the achievement of safe collaborative human-robot work. Additionally, a review is provided of the current regulations along with new concepts that have been introduced in them. The discussion presented in this paper includes multidisciplinary approaches, such as techniques for estimation and the evaluation of injuries in human-robot collisions, mechanical and software devices designed to minimize the consequences of human-robot impact, impact detection systems, and strategies to prevent collisions or minimize their consequences when they occur

Aplicación de inteligencia artificial en sistemas automatizados de producción

“Soy un gigante tan gigante que puedo grabar una rosa en la uña de un niño recién nacido”. Para solucionar el problema el personaje de García Lorca puede emplear diferentes métodos o múltiples paradigmas, como haría un sistema de inteligencia artificial. La inteligencia artificial es “simplemente” la transferencia de la inteligencia a las máquinas, es decir que el computador haga cosas inteligentes. Sin embargo la inteligencia humana es una función tan compleja que los científicos están solo empezando a comprender. Como los sistemas de inteligencia artificial, el personaje seguramente posee un conocimiento concreto de hechos y factores que afectan al problema y un conocimiento abstracto de reglas e ideas para solucionarlo, y su éxito depende de la habilidad de aplicar este conocimiento a cualquier situación, y de aprender continuamente de nuevas experiencias. Las reglas que relacionan todos los hechos conocidos están expresadas por relaciones condicionales y de la misma manera que el ser humano, puede procesar un gran número de impresiones sensoriales que le llegan al mismo tiempo y que son irrelevantes al problema. Mediante un sofisticado proceso de selección debe eliminar los caminos de razonamiento que no son vitales para resolver el problema concreto. El objetivo final se alcanza cumpliendo una serie de metas intermedias, ya que sin objetivos que lograr no existe razón para pensar, es decir, “no hacemos cosas porque pensamos sino que pensamos porque hay cosas que tenemos que hacer”. Las técnicas de inteligencia artificial son capaces tanto de sustituir elementos tradicionales de control como de realizar tareas que hasta el momento era imposible abordar sin la presencia del operador humano. Se presentan a continuación una serie de aplicaciones en las que el Grupo de Ingeniería de Control de la Universidad de Cantabria ha empleado herramientas de inteligencia artificial para aplicaciones de automatización y control de sistemas complejos

Ultrasonic Sensors in Urban Traffic Driving-Aid Systems

Currently, vehicles are often equipped with active safety systems to reduce the risk of accidents, most of which occur in urban environments. The most prominent include Antilock Braking Systems (ABS), Traction Control and Stability Control. All these systems use different kinds of sensors to constantly monitor the conditions of the vehicle, and act in an emergency. In this paper the use of ultrasonic sensors in active safety systems for urban traffic is proposed, and the advantages and disadvantages when compared to other sensors are discussed. Adaptive Cruise Control (ACC) for urban traffic based on ultrasounds is presented as an application example. The proposed system has been implemented in a fully-automated prototype vehicle and has been tested under real traffic conditions. The results confirm the good performance of ultrasonic sensors in these systems

Sistema de visión ultrasónica para invidentes

Consiste en unas gafas en cuyas patillas van alojados unos pequeños sensores de ultrasonidos, que van conectados a una unidad autónoma que procesa la información de estos sensores y proporciona una señal, bien de presión, acústica o vibratoria, a la persona invidente que las lleva advirtiendo de la presencia y orientación de cualquier cuerpo u objeto situado en un entorno cercano, incluyendo estructuras tipo andamio que resultan muy peligrosas para estas personas.Solicitud: 009901199 (27.05.1999)Nº Pub. de Solicitud: ES2158786A1 (01.09.2001)Nº de Patente: ES2158786B1 (16.03.2002

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

Simulador de cirugía cardiotorácica

La invención se refiere a un simulador de cirugía cardiotorácica que comprende: -un bloque cardiopulmonar, con un corazón y unos pulmones inertes; y,- un circuito hidráulico cerrado para reproducir una parte de un sistema cardiovascular, con un depósito de fluido en conexión fluida con un elemento de bombeo configurado para producir un flujo continuo de dicho fluido desde el depósito hacia dos circuitos:- un circuito principal que atraviesa el bloque cardiopulmonar con un primer elemento de control de flujo aguas arriba del bloque cardiopulmonar y un segundo elemento de control de flujo aguas abajo del bloque cardiopulmonar, retornando este primer circuito principal al depósito de fluido aguas abajo del segundo elemento de control de flujo;- un circuito auxiliar, paralelo al circuito principal con retorno al depósito de fluido y que comprende un tercer elemento de control de flujo; comprendiendo el simulador de cirugía cardiotorácica además medios de control configurados:- para actuar alternativamente sobre el primer elemento de control de flujo y el tercer elemento de control de flujo produciendo un flujo alternante de fluido entre el circuito principal y el circuito auxiliar; y- para actuar desfasadamente sobre el primer elemento de control de flujo y sobre el segundo elemento de control de flujo produciendo un pulso de presión dentro del bloque cardiopulmonar; de forma que se produce un flujo pulsátil del fluido a través del bloque cardiopulmonar.Solicitud: 201930264 (25.03.2019)Nº Pub. de Solicitud: ES2784447A1 (25.09.2020)Nº de Patente: ES2784447B2 (06.07.2021

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