National Repository of Grey Literature 24 records found  1 - 10nextend  jump to record: Search took 0.01 seconds. 
Analysis of Pedestrian Recognition by the Vehicle Driver
Šlapal, David ; Kropáč, František (referee) ; Maxera, Pavel (advisor)
This diploma thesis deals with vehicle driver’s recognition of pedestrian in different driving and light conditions. The introductory part will be devoted to basic theoretical knowledge. The attention is focused on safety measures to prevent accidents between pedestrians and vehicles. The main part will be devoted to the pedestrian´s visibility from the driver´s point of view during reduced visibility on roads in darkness. The practical part of this work summarizes the results of the experiment using the selected vehicle and chosen participants. During this experiment, the distance necessary for detection, recognition and identification of the pedestrian will be measured, to stop the vehicle safety in time or to avoid an obstacle on the road.
A Tool for Database Content Analysis for Testing Purposes
Kropáč, František ; Šimková, Hana (referee) ; Smrčka, Aleš (advisor)
Acceptance testing of applications before the production includes testing of scenarios resembling situations of real usage of the application. Creating the test data is complicated matter since the data are specified by restrictions concerning the domain of the tested application and the specifications of the structural restrictions and the relations between these data. This thesis focuses on the issues of detecting the data constraints in an already created relational database. The outcome of the thesis is a tool which automatically controls and mediates the detection of the data constraints in a relational database. The detection result is a weight rating of the data restrictions, which represents both the data type and the relation between tables, columns in relational database. These restrictions can be used to generate a random testing data which would represent inputs for seemingly realistic scenarios of the usage of the application.
Analysis of impact of active safety elements in vehicles on pedestrian protection for traffic accident investigation
Vertaľ, Peter ; Kovanda, Jan (referee) ; Kropáč, František (referee) ; Vémola, Aleš (advisor)
Increase the probability of prevent road accidents by installing autonomous systems in a vehicles is the current trend in the field of active safety with a focus on pedestrian safety. The work deals with the evaluation of intervention of active safety systém for pedestrian detection assembled in series production. Benefit of active safety systems to prevent road accidents can be achieved, for example, early warning driver of a potential collision situation sufficiently in advance to reaction and post-maneuver (braking, yaw, ..). The evaluation of the intervention of active safety systems, which aim to prevent an accident with a pedestrian is necessary to experimentally evaluate the behavior of these systems. The main objective of this work is to test the selected systém based on different types of reál accidents. Atthe time of the measurements and present, are not for experts and specialists in the field of road traffic accidents publicly accessible data about the behavior of such a systém. The work aims to evaluate the behavior of the Volvo systém in inducing reál traffic situations. For the evaluation of this systém are precisely analyzed fatal traffic accidents with pedestrians in the urban area (speed of vehicles up to 60 km/h). Simulated traffic situations by their nature cover the most common critical situations in urban traffic. Expert community and the professionals who deal with the solution of traffic accidents receive this work valuable data to deal with such accidents. Based on these measurements give more expert input data to solve a collision with a pedestrian. The basis for understanding the behavior are created graphs of distance, speed and time at a key moment of the collision. These key moments include entry a pedestrians to driving corridor of the vehicle, system's response to conflict situations, warn the driver and then autonomously brake active safety systém
COMPLEX ANALYSIS OF COMMON OBSERVATION TIME OF MOVING VEHICLE AND ENVIRONMENTAL CONDITIONS FOR EVALUATION OF TRAFFIC SITUATION
Sedlák, Robert ; Rábek, Vlastimil (referee) ; Kropáč, František (referee) ; Bradáč, Albert (advisor)
In the doctoral thesis is derived a theoretical equations for calculating the minimum recognizable change in position of an object by the observer. To assess the suitability of this approach theory tests were carried out on the test track. Tests confirmed the theoretical explanation for three of the five test persons. In the event of a head-on observations were at greater distances longer times of fixation, at the side watching the observation times at short and long distances were without significant differences. Further tests were carried out in urban traffic intersections in day and night time Statistical evaluation was found that if to the intersection did not come any vehicle, the median observation time was 0,4 s (night) and 0,56 s (day), if to the intersection were coming vehicle, the median observation time was 0,74 (night) and 1,06 (day), the median of the check view was 0,12 s for both day and night. There were also statistically evaluated motor skills of turning the driver's head when looking around the intersection. The median time interval rotation of the head from a straight line to the left, straight line to the right and vice versa was 0,36 s, median time period of rotation of the head from left to right and vice versa was 0,56 s.
Comprehensive System for Road Accident Analysis - Collision Between Vehicle and Motorcycle
Slepánek, Petr ; Kolíbal, Zdeněk (referee) ; Drahotský, Ivo (referee) ; Kropáč, František (referee) ; Bradáč, Albert (advisor)
This dissertation describes the issue of a complex system for analyzing the collision of a motorcycle with another vehicle and suggests a suitable methodology for solving this type of traffic accident. It summarizes the current knowledge in the field of motorcycle accidents withother vehicles, including their statistics and categorization. The author statistically evaluates accidents by their causes and proposes a methodology for solving individual types of motorcycle collisions with vehicles. To supplement and refine the input data for the analysis of road accidents involving motorcycles, a set of author’s own measurements made on different types of motorcycles is included. The thesis contains measurements of their acceleration, deceleration and avoidance maneuvers. Other actual contributions of the thesis are represented also by flowcharts, offering a comprehensive approach to solving individual types of colissions of motorcycles with other vehicles.
Processing of selected terminology at road accident analysis
Tokař, Stanislav ; Šachl, Jindřich (referee) ; Kropáč, František (referee) ; Drahotský, Ivo (referee) ; Vémola, Aleš (advisor)
The thesis deals with the terminology used in forensic engineering practice at the analysis of road accidents. It means defining the concepts describing specific expert research in the area of car accident analysis such as the option of evasive action and the possibility of preventing collision. Further on, the thesis focuses on the terminology used in areas closely related to analysis of road accidents namely dealing with cases of criminal activities in the field of motor vehicle insurance from an expert point of view. In this area, terms such as extent of the damage, character of the damage, correspondence of the damage and the technical acceptability of accident, are solved. These terms constitute a formal process that can serve as a tool for experts when dealing with such cases. In addition, selected terms from the technical-legal area, which the experts often encounter, are processed here. At the same time, there is no uniform approach to their evaluation from a technical perspective. Here, there is a possibility of setting the limits of a sudden change of speed and a sudden change of direction.
Lane change manoeuvre of modern vehicles on wet surface
Mikulec, Roman ; Kropáč, František (referee) ; Mičunek, Tomáš (referee) ; Semela, Marek (advisor)
This dissertation investigates the possibilities of determining the minimal duration of modern vehicles lane change manoeuvre on the wet road surface. In cases when the driver changed lanes or swerved before or during the crash, analysis of this manoeuvre should be carried out, as well as part of a collision avoidance investigation. The issue of lane change has been addressed in several theses in the past, but most of these theses were based on the results of measurements on the dry road surface. It is, therefore, necessary to investigate the applicability of the existing calculation methods to the situation of reduced adhesion conditions, together with the considerable time lag from most of the earlier studies, and therefore the considerable advances in vehicle design and driving stability systems. For this reason, several series of driving tests have been carried out with modern vehicles on predominantly wet road surfaces. These measurements have provided essential input and output variables used to analyse the current calculation methods and determine the set-up of the driving stability systems in simulation programs. Based on the statistical analysis, the so-called Kovařík equation, which has been used so far, was evaluated as the most suitable method for calculating the duration of lane-change manoeuvre, for which a new value of the mathematical constant was found. An alternative calculation of the longitudinal distance travelled by the vehicle in the manoeuvre is also presented in this dissertation.
Comprehensive System for Road Accident Analysis - Collision Between Vehicle and Motorcycle
Slepánek, Petr ; Kolíbal, Zdeněk (referee) ; Drahotský, Ivo (referee) ; Kropáč, František (referee) ; Bradáč, Albert (advisor)
The thesis describes the problems of a complex system for analysis of road accidents, specifically the methodology for solving the collision between vehicle and motorcycle. There are statistics described motorcycle accidents, motorcycle safety features, the basic types of collision positions between vehicles and motorcycles, design methodology for solving with traffic accidents between vehicles and motorcycles. The work is performed a set of different measurements used to supplement and refine the input data for the analysis of road accidents involving motorcycles. The work contains data obtained from measurements.
Analysis of Driving a Passenger Vehicle with a Trailer
Šujan, Tomáš ; Kropáč, František (referee) ; Vémola, Aleš (advisor)
The subject of this thesis is the analysis of the negative effects associated with the operation of a trailer for a personal vehicle with respect to the design speed, technical checks and analysis related legislation. Its work is drawn from the measurement, cooperation with leading Czech production plant trailers Vezeko s.r.o., an organization engaged in the implementation of engineering controls DEKRA Automobil a.s. and available literature, including electronic resources. Results of the work end with proposals for specific measures to minimize the identified adverse effects.
The Lighting Equipment Used in Modern Vehicles and the Measurement of the Range of Visibility of the Rear Lights
Belák, Michal ; Kropáč, František (referee) ; Vémola, Aleš (advisor)
This work is about lighting equipment of modern vehicles, its historical development, present condition and possibilities of its further progress and measuring of the range of visibility of the rear lights. First part is aimed at lighting equipment used in modern vehicles as a whole. It describes sources of light, their principle, construction, advantages and disadvantages. Next it deals with searchlights and other lighting devices, their gradual development, construction and modern solutions which are used in them, and also their future development. Second part of the work is aimed at characterization of ways of measuring the range of visibility used in practice, their possible application to measuring of the range of visibility of the rear lights and on proposal of presentive methodics for this measurement. Realization and interpretation of practical measurement by this methodics is included.

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