Vehicle Safety Assist Systems and Their Assessment under Euro NCAP Directives

Cieľom bakalárskej práce bol vytvoriť prehlad o súčasných asistenčných systémov automobilov a preukázať ich vplyv na bezpečnosť cestnej premávky. V prvej časti boli systémy kategorizované podľa ich charakteristiky a funkčnosti. Ďalej bol vytvorený prieskum o vývoji nehodovosti a boli demonštrované najčastejšie príčiny dopravných nehôd. V druhej části bol rozobraný princíp fungovania brzdových asistenčných systémov a systém automatického núdzového brzdenia. V poslednej časti tejto práci boli predovšetkým vysvetlené hodnotenia podľa smerníc Euro NCAP, kde pozornosť sa zameriavala na hodnotenie skúšok súčasných asistenčných systémov.The aim of this bachelor’s thesis was to create overview about vehicle safety assist systems and to show their impact of road traffic safety. In the first part of this thesis systems were categorized by their function and characteristic.After that there were created a survey about accident rate and there were shown the most common causes in road accidents. In the second part was discussed principle how brake assist systems and automatic emergency braking work. In the last section was explained assessment under Euro NCAP directives, where the attention was focused onassesment of the experimentsof safety assist.

Heterogeneous conductivity parameters in a one dimensional fuel cell model

A model of one dimensional fuel cells is investigated, where the material inhomogeneities in the cathode are taken into account. We use the results in some preceding studies to describe the dynamics of the chemical reactions and transport of ions. A corresponding governing equation is derived for the numerical simulations. We apply an explicit-implicit time integration and Richardson extrapolation technique to increase the accuracy of the approximations. The efficiency of the method is demonstrated using a non-trivial test problem with real parameters. Numerical simulations are executed in presence of inhomogeneous conductivities and their effect on the cell potential is investigated

Simulation and experimental validation of the dynamical model of a dual-rotor vibrotactor

In this work, a novel design for small vibrotactors called the Dual Excenter is presented, which makes it possible to produce vibrations with independently adjustable frequency and amplitude. This feature has been realized using two coaxially aligned eccentric rotors, which are driven by DC motors independently. The prototype of the device has been built, where mechanical components are integrated on a frame with two optical sensors for the measurement of angular velocity and phase angle. The system is equipped with a digital controller. Simulations confirm the results of analytical investigations and they allow us to model the sampling method of the signals of the angular velocity and the phase angle between the rotors. Furthermore, we model the discrete behavior of the controller, which is a PI controller for the angular velocities and a PID controller for the phase angle. Finally, simulation results are compared to experimental ones, which show that the Dual Excenter concept is feasible

Advanced tactile feedback with dual-rotor vibrotactor

A novel solution is presented for generating advanced tactile feedback in haptic applications. The concept utilizes the benefits of the eccentric rotating mass (ERM) vibrotactors and eliminates the problem of the frequency-dependent amplitude by using two eccentric rotors. Operational region of the dual-rotor vibrotactor is showed in the frequency-amplitude domain considering tactile sensing threshold of the human skin, and the possibility of changing the intensity of the tactile stimuli by the dual-rotor vibrotactor is compared to common ERM vibrotactors

Relationship between the body condition and the appearance parameters of Holstein-Friesian cows

The body condition has been part of the livestock judgment in Hungary since 2007. This date can be called relatively late, because in Ireland and Britain body condition scoring has been part of the conformation judging system of Holstein-Friesian cows since 1996. In our study we analysed the mean of linear characteristics within lactations, and compared the results to the ideal values of each characteristic. We also analysed the correlation between body condition and linear type traits. The results of the relationship between the body condition and the linear descriptive characteristics in case of body measurement are weak (r=0.09), or medium (r=0.29) and except for the angularity (between r=-0.39 and r=-0.50) they are positive. When analysing the main functional areas, we also compared the difference among the scores of the lactations. We investigated the relationship between the body condition and the main functional types. Overall we founded that the increase in the number of lactations as well as the improving body condition had a positive effect on the body score. When investigating the relationship between the body condition and the dairy strength a negative correlation was found between these two attributes

Vibrator with DC motor driven eccentric rotors

DC motor drives are widely used in many devices in mechatronics and industry. Since the performance of these motors depends on their angular velocity, there are some interesting phenomena originating from the counter-action of the drive and the driven mechanical system. The present work proposes a four-degree-of-freedom mechanical model with two DC motor driven eccentric rotors. Only translational in-plane motion of the base is considered. Based on the stationary motions of the proposed system, the changed DC motor performance and the phenomenon of self-synchronization have been showed analytically and by some simulation results

A forgalomban lévő fásszárú dísznövénytaxonok szárazságtűrésének értékelése a klímaváltozás tükrében (Evaluation of the impact climate change on current drought-tolerant woody plants)

Regionális klímaváltozási forgatókönyvek szerint hazánk éghajlata az elkövetkező 90 évben a mainál jóval melegebb, a nyári évszakban csapadékszegényebb, összességében pedig szárazabb lesz. Kutatásunk célja volt felmérni szárazságtűrésük szerint a legjelentősebb faiskolák katalógusában fellelhető fa- és cserjefajokat (a gyűjtésben nem szerepelnek a faj alatti taxonok). A vizsgálatainkban szereplő öt faiskola növénykínálatát a tudományos nevek ellenőrzése után összesítettük, majd ezt követően az egyes fajokat vízigény szerinti kategóriákba soroltuk. A tényleges statisztikai értékelésbe – a 451 összegyűjtött faj tudományos neveinek ellenőrzése után – 420 fajt vontunk be, melyek 20%-a vízigényes, 53%-a közepesen vízigényes és 27%-a szárazságtűrő. Várakozásainkkal ellentétben a vízigényes fajok részaránya kevésnek mondható, ugyanakkor a szárazságtűrő fajok magasabb aránya kívánatos lenne. Ezért, a gyakorlati alkalmazást elősegítve, kiemeltünk olyan nemzetségeket, melyek kereskedelmi forgalmazását meg kellene kezdeni vagy fokozni, mint pl a Cupressus, Eucommia, Halimodendron, Paliurus, Pyrus, Rhus, Yucca Zanthoxylum, Zelkova, illetve olyanokat, melyek telepítését a jövőben nem, vagy csak kellő körültekintéssel javasoljuk, mint például a Clematis, Hydrangea, Liquidambar, Magnolia, Rhododendron nemzetségek. _____ According to regional climate change scenarios, the climate in Hungary will be warmer. Less precipitation is predicted in the summer seasons so, on the whole, it will be drier over the next 90 years. Our research attempted to survey the ornamental plant species in the most important nurseries in Hungary, in terms of their drought tolerance. The intraspecifi c taxa are not included. The plant assortment of the fi ve nurseries was merged after researching their scientifi c names. We then categorized species to 3 groups of drought tolerance. Out of 451 species, 420 of them were used in the statistical research. 20% of them were water demanding, 53% were medium drought tolerant and 27% were drought tolerant. In contrast to our initial expectation, the proportion of water demanding species was not too high. Nevertheless, the proportion of drought tolerant species should have been greater. We classifi ed the genera to assist in practical application. The trade of some of these species, such as Cupressus, Eucommia, Halimodendron, Paliurus, Pyrus, Rhus, Yucca, Zanthoxylum, Zelkova should be initiated or increased in the future. Other species, especially Clematis, Hydrangea, Liquidambar, Magnolia, Rhododendron are not recommended due to either their drought intolerance or their high maintenance requirement