Vision-based active safety system for automatic stopping

ntelligent systems designed to reduce highway fatalities have been widely applied in the automotive sector in the last decade. Of all users of transport systems, pedestrians are the most vulnerable in crashes as they are unprotected. This paper deals with an autonomous intelligent emergency system designed to avoid collisions with pedestrians. The system consists of a fuzzy controller based on the time-to-collision estimate – obtained via a vision-based system – and the wheel-locking probability – obtained via the vehicle’s CAN bus – that generates a safe braking action. The system has been tested in a real car – a convertible Citroën C3 Pluriel – equipped with an automated electro-hydraulic braking system capable of working in parallel with the vehicle’s original braking circuit. The system is used as a last resort in the case that an unexpected pedestrian is in the lane and all the warnings have failed to produce a response from the driver.

Teller: telemetría a partir de datos GPS

El avance y desarrollo de las nuevas tecnologías ha GPS sean cada vez más efectivos y precisos. En la actualidad son usados por miles de personas en una gran variedad de aplicaciones, siendo la competición una de ellas.Detrás del funcionamiento de estas pequeñas unidades juega un papel muy importante la telemetría, una tecnología que cada vez es más relevante en el mundo actual, y que gracias a las avances tecnológicos sus aplicaciones son cada vez mayores. En este Trabajo de Fin de Grado se diseñará Teller, un programa realizado en Erlang que mediante la telemetría y la tecnología actual realizará cálculos físicos de recorridos realizados en motocicleta, tales como velocidad o aceleración (tangencial y radial), además de clasificar los trayectos en tramos, dependiendo de si son curvas o rectas. Al mismo tiempo se realizará un estudio de precisión del dispositivo GPS, cotejando sus datos con los obtenidos por Teller. Por último, toda esta información se mostrará en un mapa para que el usuario pueda visualizarlo y que de esta forma sirva como herramienta de información y aprendizaje. The development of new technologies has contributed to the improvement of GPS devices, making them more effective and accurate. Nowadays they are used by thousands of people in a wide variety of applications like competitions. The technology that is behind the functionality of those devices is the telemetry, which is getting more and more important in the real world. In this thesis a new program called Teller will be designed. Made in Erlang, it will use telemetry so as to obtain new and valuable data from a motorcycle track. Examples of this type of data can be speed and acceleration (either tangential and radial) for instance. Besides, Teller will classify the track into segments, depending if it is a curve or a straight. At the same time a study will be carried out in order to know how accurate the GPS device is. This will be achieved by comparing the data retrieved by the device with the data calculated by Teller. Finally, all this information will be shown in a map, so the user can see information about his route in a visual way. xi

Sight distance for traffic safety analysis using GIS

Sight distance is of major importance for road safety either when designing new roads or analysing the alignment of existing roads. It is essential that available sight distance in roads is long enough for emergency stops or overtaking manoeuvres. Also, it is vital for engineers/researchers that the tools used for that analysis are both powerful and intuitive. Based on ArcGIS, the application to be presented not only performs an exhaustive sight distance calculation, but allows an accurate analysis of 3D alignment, using all new tools, from a Digital Elevation Model and vehicle trajectory. The software has been successfully utilised to analyse several two-lane rural roads in Spain. In addition, the software produces thematic maps representing sight distance in which supplementary information about crashes, traffic flow, speed or design consistency could be included, allowing traffic safety studies.

Reliable Spreading of messages in not eponymous systems

The broadcast service spreads a message m among all processes of the system, such that each process eventually delivers m. A basic broadcast service does not impose any delivery guarantee in a system with failures. Fault-tolerant broadcast is a fundamental problem in distributed systems that adds certainty in the delivery of messages when crashes can happen in the system. Traditionally, the fault-tolerant broadcast service has been studied in classical distributed systems when each process has a unique identity (eponymous system). In this paper we study the fault-tolerant broadcast service in anonymous systems, that is, in systems where all processes are indistinguishable.

Spatial analysis of geometric design consistency and road sight distance

Because of the high number of crashes occurring on highways, it is necessary to intensify the search for new tools that help in understanding their causes. This research explores the use of a geographic information system (GIS) for an integrated analysis, taking into account two accident-related factors: design consistency (DC) (based on vehicle speed) and available sight distance (ASD) (based on visibility). Both factors require specific GIS software add-ins, which are explained. Digital terrain models (DTMs), vehicle paths, road centerlines, a speed prediction model, and crash data are integrated in the GIS. The usefulness of this approach has been assessed through a study of more than 500 crashes. From a regularly spaced grid, the terrain (bare ground) has been modeled through a triangulated irregular network (TIN). The length of the roads analyzed is greater than 100 km. Results have shown that DC and ASD could be related to crashes in approximately 4% of cases. In order to illustrate the potential of GIS, two crashes are fully analyzed: a car rollover after running off road on the right side and a rear-end collision of two moving vehicles. Although this procedure uses two software add-ins that are available only for ArcGIS, the study gives a practical demonstration of the suitability of GIS for conducting integrated studies of road safety.

Eventual election of multiple leaders for solving consensus in anonymous systems

In classical distributed systems, each process has a unique identity. Today, new distributed systems have emerged where a unique identity is not always possible to be assigned to each process. For example, in many sensor networks a unique identity is not possible to be included in each device due to its small storage capacity, reduced computational power, or the huge number of devices to be identified. In these cases, we have to work with anonymous distributed systems where processes cannot be identified. Consensus cannot be solved in classical and anonymous asynchronous distributed systems where processes can crash. To bypass this impossibility result, failure detectors are added to these systems. It is known that ? is the weakest failure detector class for solving consensus in classical asynchronous systems when amajority of processes never crashes. Although A? was introduced as an anonymous version of ?, to find the weakest failure detector in anonymous systems to solve consensus when amajority of processes never crashes is nowadays an open question. Furthermore, A? has the important drawback that it is not implementable. Very recently, A? has been introduced as a counterpart of ? for anonymous systems. In this paper, we show that the A? failure detector class is strictly weaker than A? (i.e., A? provides less information about process crashes than A?). We also present in this paper the first implementation of A? (hence, we also show that A? is implementable), and, finally, we include the first implementation of consensus in anonymous asynchronous systems augmented with A? and where a majority of processes does not crash.