Making Transport Safer: V2V-Based Automated Emergency Braking System

An important goal in the field of intelligent transportation systems (ITS) is to provide driving aids aimed at preventing accidents and reducing the number of traffic victims. The commonest traffic accidents in urban areas are due to sudden braking that demands a very fast response on the part of drivers. Attempts to solve this problem have motivated many ITS advances including the detection of the intention of surrounding cars using lasers, radars or cameras. However, this might not be enough to increase safety when there is a danger of collision. Vehicle to vehicle communications are needed to ensure that the other intentions of cars are also available. The article describes the development of a controller to perform an emergency stop via an electro-hydraulic braking system employed on dry asphalt. An original V2V communication scheme based on WiFi cards has been used for broadcasting positioning information to other vehicles. The reliability of the scheme has been theoretically analyzed to estimate its performance when the number of vehicles involved is much higher. This controller has been incorporated into the AUTOPIA program control for automatic cars. The system has been implemented in Citroën C3 Pluriel, and various tests were performed to evaluate its operation

Computer modeling of the process of overturning of the automobile

The article deals with investigation of the possibilities of the program PC CRASH, meant for the computer modeling of the movement of vehicles. The computer modeling of the process of overturning of the automobile with the help of the program PC CRASH is introduced. The cross profile of the road, the height of the centre of gravity of the automobile and the other parameters are evaluated while modeling. The influence of the introduced parameters upon the computer modeling results is investigated. The possibilities of application of the computer modeling programs in the expert assessment of the traffic accidents are considered, the items on reliability of the results of modeling and the requirements, raised towards the experts, who work with such programs, are analyzed

Investigation of the interaction of an automobile wheel with a vertical obstacle

Collision of automobile wheels with a vertical obstacle as a result of which the wheel tire gets dismantled is considered in the present article. The required force and the minimal speed of driving which is equivalent to the expenditures of the kinetic energy necessary for dismantling of the tire from the wheel rim after the collision with an obstacle are ascertained. The values of this force and speed typical of automobiles attributed to different classes, their dependence upon the height of the obstacle and the angle of collision with the obstacle are fixed. A more precise method for the calculation of the automobile speed prior to the traffic accident taking into consideration the expenditures of the kinetic energy necessary for dismantling of the wheel after the occurrence of its collision with a vertical obstacle is suggested

Automobile braking and traction characteristics on the different road surfaces

The present article depicts the results of the investigation into automobile braking parameters and traction characteristics on the different road surfaces. The results of the investigation into automobile braking (the automobile deceleration and coefficient of traction), while braking in winter conditions, i. e. on ice and snow, are presented. The values of deceleration of the automobile while braking on various non-typical surfaces, on the asphalt, covered with the motor oil or resin, while driving across the petrol spot, and on other surfaces of the road, are presented. Such data are necessary while modelling the automobile’s movement in various road conditions and while carrying out the examination of traffic accidents

Poprawa i ocena niezawodności opartej na wektorowej metodzie trajektorii Dubinsa dla korekty trajektorii pojazdów autonomicznych

Due to global purposes to ensure growth of a competitive and sustainable transport system, also to solve traffic safety and environmental problems, various engineering solutions are being sought out. It can be assumed that autonomous vehicles are the technology, which will ensure the positive change in the transport system. Even though many studies successfully advanced toward realisation of autonomous vehicles, a significant amount of technical and policy framework problems still has to be solved. This paper addresses the problem of predefined path feasibility and proposes an effective methodology for a path to follow re-planning. The proposed methodology is composed of three parts and is based on the Dubins path approach. In order to modify the vector based Dubins path approach and to ensure the path feasibility, the optimisation problem was solved. A cost function with different inequality constraints was formulated. The performance and reliability of the proposed methodology were analysed and evaluated by carrying out an experimental research while using the autonomous test vehicle.Dla zapewnienia rozwoju konkurencyjnego i zrównoważonego systemu transportowego, oraz w celu rozwiązania problemów związanych z bezpieczeństwem ruchu i środowiskiem, poszukiwane są różne rozwiązania techniczne. Można założyć, że autonomiczne pojazdy są technologią, która zapewni pozytywną zmianę w systemie transportowym. Mimo że wiele badań z powodzeniem dotyczyło realizacji autonomicznych pojazdów, należy jeszcze rozwiązać wiele problemów technicznych i prawnych. W niniejszym dokumencie poruszono problem predefiniowanej wykonalności ścieżki i zaproponowano skuteczną metodologię dla ścieżki do śledzenia ponownego planowania. Proponowana metodologia składa się z trzech części i opiera się na metodzie Dubinsa. Aby zmodyfikować metodę trajektorii Dubinsa i zapewnić optymalną trajektorię, w publikacji rozwiązano zadanie optymalizacji. Sformułowana funkcja celu z różnymi nieliniowymi ograniczeniami. Skuteczność i niezawodność proponowanej metodologii została przeanalizowana i oceniona po przeprowadzeniu eksperymentalnych badań z wykorzystaniem autonomicznego pojazdu badawczego

Traffic control elements influence on accidents, mobility and the environment

This paper presents the main traffic control elements, which were classified into groups. One group presents traffic control elements, which have different effects on accidents: reduce the number of accidents, do not have statistically significant effect on the number of accidents and those which appear to lead to an increased number of accidents. Next group presents traffic control elements, which have effect on mobility and the environment. Some of them can improve mobility on road, others reduce mobility on road. Presented elements, which are useful for the environment, are considered

Badania dynamicznych charakterystyk ruchu pojazdu na nierównościach drogi

The paper analyses the effect of road roughness on the variation of the vertical oscillations’ frequency of the sprung and unsprung masses of a vehicle driving at varying speed. The research aims to determine the regularity with which the wheel of a vehicle moving at varying speed reproduces the roughness of road pavement texture. The theory of mathematical statistics is used to define the distribution law of road defects measured during the experiment. In the present investigation, the displacements of the wheel and suspension of the vehicle, driving at varying speed over the defects of the selected road section pavement, have been evaluated. Based on the frequency characteristic obtained from the measured data, the frequency variation of the displacements of the sprung and unsprung masses in a vehicle moving on a rough road has been determined. The vertical acceleration of the wheel and the body of a vehicle has been measured, and the frequency characteristic of vertical acceleration of the sprung and unsprung vehicles’ masses has been analysed. The schematic view of the wheel’s axis displacement model is presented.Artykuł analizuje wpływ nierówności drogi na zmiany częstotliwości dynamiki pionowej resorowanych i nieresorowanych mas samochodu przy różnych prędkościach. Celem jest określenie wzoru nierówności drogi przy różnych prędkościach, za pomoca analizy zmian częstotliwości drgań kół pojazdu. Podczas przeprowadzonego eksperymentu zmierzono nierówności drogi i za pomocą teorii analizy matematycznej określono charakterystykę nierówności nawierzchni. Podczas prób jazdy po nierównościach wybranego odcinka drogi przy różnych prędkościach zmierzono przesunięcia pionowe koła i zawieszenia samochodu. Na podstawie charakterystyki częstotliwościowej oceniono zmiany częstotliwości przebiegów pionowych resorowanych i nieresorowanych mas pojazdu jadącego po nierównościach drogi. Zmierzono przyspieszenia pionowe koła oraz nadwozia i przeprowadzono analizę częstotliwości przyspieszeń pionowych resorowanych i nieresorowanych mas. Przedstawiony jest schematyczny model przesunięć osi koła

Ocena nierówności drogowych zgodnie z danymi czujników zainstalowanych na pojeździe

Artykuł przedstawia i ocenia metody określania nierówności nawierzchni drogi na podstawie danych z laserowych czujników pomiaru odległości. W artykule omówiono opracowane w Japonii symetryczne i asymetryczne metody określania nierówności nawierzchni, które różnią się sposobem rozmieszczenia czujników i przetwarzania danych. Badania eksperymentalne przeprowadzone na podstawie „metody japońskiej” na dwóch zadanych profilach nawierzchni pozwoliły na ocenę wpływu zawieszenia samochodu i zmian przechyłu nadwozia względem osi podłużnej na obliczanie nierówności nawierzchni. Walidacja wyników pokazała, że kompensacja odchylenia zawieszenia nie zapewnia wystarczającej dokładności pomiaru nierówności drogi, ponieważ przechyły nadwozia mają większy wpływ na przetwarzanie sygnałów rejestrowanych przez zamontowane na nim czujniki.In this work, methods of estimation of road roughness by processing data of laser sensors of distance measurement are investigated. Depending on the layout of the sensors and the processing of the data, the Japanese, symmetrical and asymmetrical roughness estimation methods are elaborated in this work. The experimental research that was carried out by “Japanese method” on two known profile road surfaces allowed evaluating the influence of the vehicle’s suspension and the body pitch rate oscillation on the calculation of the roughness. The validation of the results showed that the compensation of the suspension travel does not warrant the sufficient accuracy of the estimation of the road roughness because the pivoting of the bodywork has a greater influence on the processing of the signals recorded by the sensors attached to it