RANGE EXTENDER ICE MULTI-PARAMETRIC MULTI-OBJECTIVE OPTIMIZATION

Range Extended Electric Vehicles (REEV) are still one of the suitable concepts for modern sustainable low emission vehicles. REEV is equipped with a small and lightweight unit, comprised usually of an internal combustion engine with an electric generator, and has thus the technical potential to overcome the main limitations of a pure electric vehicle – range anxiety, overall driving range, heating, and air-conditioning demands – using smaller battery: saving money, and raw materials. Even though several REx ICE concepts were designed in past, most of the available studies lack more complex design and optimization approach, not exploiting the advantageous single point operation of these engines. Resulting engine designs are usually rather conservative, not optimized for the best efficiency. This paper presents a multi-parametric and multi-objective optimization approach, that is applied on a REx ICE. Our optimization toolchain combines a parametric GT-Suite ICE simulation model, modeFRONTIER optimization software with various optimization strategies, and a parametric CAD model, that first provides some simulation model inputs, and second also serves for the final designs’ feasibility check. The chosen ICE concept is a 90 degrees V-twin engine, four-stroke, spark-ignition, naturally aspirated, port injected, OHV engine. The optimization goal is to find the thermodynamic optima for three different design scenarios of our concept – three different engine displacements – addressing the compactness requirement of a REx ICE. The optimization results show great fuel efficiency potential by applying our optimization methodology, following the general trends in increasing ICE efficiency, and power for a naturally aspirated concept.

CRITICAL SHIFTING WINDOW IN SWITCHABLE ROCKER FINGER FOLLOWER

A valvetrain including switchable rocker finger follower is capable of discrete switching between two modes (two cam profiles). The exact moment when switching occurs is called crossover point and this paper reviews the factors that cause the shift of the crossover point from its nominal design position. The range where crossover point can shift is called critical shifting window and its size and factors influencing it will be adressed.

SOFTWARE FOR THE DESIGN OF GEARING WITH AN ASYMMETRIC PROFILE

This article is a continuation of previously published articles. This paper briefly describes the positive and negative qualities of asymmetric gearing from the point of view of loading conditions applied at the gearset, and the development and latest update of the software for designing this special involute gearing. The precise profile of the manufacturing tool is also described. All display options, and the option of gear mesh animation using this program, is shown. All equations necessary for the gearing geometry description, and a special approach with respect to x-shift coefficients distribution, are also mentioned in this paper.

NEW ADVANCED METHODS IN SIDE CRASH TESTING

This work follows up the previous work [1] regarding the used methodology in the field of passive safety, ie. crash testing. The work is based on experience gained in the Active Lateral Impact Simulator (ALIS) project and describes complete process. The main focus has been given to the fine-tuning of the boundary conditions and loading of the system in order to ensure correct biomechanical loads.

EVALUATION OF PLUG-IN PARALLEL HEV TOPOLOGIES USING OPTIMAL CONTROL METHODS AND VEHICLE DYNAMICS SIMULATION

Hybrid electric vehicle (HEV) powertrains with parallel topologies are among the frequently used layouts, because of their easy applicability on an existing conventional powertrain, by the addition of hybrid modules with mild, full, or a plug-in capability. This paper investigates three of such parallel HEV topologies: P2, P3, and P4; all in a plug-in variant, to find-out which one performs best. Apart from the topology consideration, one of the other common questions or challenges in HEV development is the ICE concept selection. To address it, the paper combines the three HEV topologies with three technologically different internal combustion engines, all with the same power outputs. Then, all the powertrain and ICE combinations are tested in homologation driving cycles and vehicle dynamics simulation test – different acceleration tests – giving a holistic methodology suitable for thorough HEV topology evaluation, identifying all possible hybridization benefits. To find the maximum CO2 potential, it is convenient to exclude the effect of the energy management control strategy on the CO2 result in a charge sustaining driving cycle; therefore, to use some optimal control method. For this task, the paper compares the Equivalent Consumption Minimization Strategy, that realizes a Pontryagin’s minimum principle against the Dynamic Programming optimal control method, which is based on Bellman’s principle of optimality. Both control methods are available as a part of GT-Suite 0D/1D/3D multi-physics CAE simulation software, that is used in our whole study.

TESTING OF AUTOMATED DRIVING SYSTEMS

The automated driving requires new testing approaches, which are more complex than the current testing systems. The complexity and requirements for accuracy is important, because of interconnection of virtual with physical testing. This paper presents a generic approach to testing of automated driving functions and demonstrates its implementation on measurement of two scenarios.Automatizované řízení vyžaduje nové testovací přístupy, které jsou daleko komplexnější než současné testovací systémy. Komplexnost a požadavky na přesnost jsou důležité z pohledu na propojení fyzického a virtuálního testování. Tento článek prezentuje obecný přístup k testování funkcí automatizovaného řízení a demonstruje jeho implementaci na měřeních dvou scénářů.

DEVELOPMENT OF A CONTROL ALGORITHM FOR A PARALLEL HYBRID POWERTRAIN

The current legislation calls for fast electrification of vehicle powertrains, since it is necessary to fulfil the CO2 requirements for the vehicle fleets. The hybrid electric vehicles (HEV) with parallel powertrain topologies – together with pure battery electric vehicles (BEV) – are the most common ways of electrification. However, the HEV powertrain – opposed to the BEV or conventional powertrain – poses an interesting challenge associated with the control system design to achieve the ideal power split between an internal combustion engine (ICE) and electrical machines (EM) during the whole vehicle operation.The presented paper sums up the specific functions and requirements on a control system, together with the description of general control strategy options for a HEV powertrain. The proposed control strategy then combines heuristic rules with a suboptimal numerical control method, calculating the optimal power split ratio based on the efficiencies of ICE and EMs. This control strategy is built into a modular algorithm in Matlab/Simulink for two different parallel HEV powertrain topologies: P2 and P0P4. It is subsequently coupled with a vehicle models created in GT-Suite environment and tested on a WLTC homologation driving cycles. The following simulation tests show the fuel consumption reduction potential for chosen HEV topologies working in hybrid modes, in comparison to a base operation with conventional mode only. Yet, the heuristic rules can be further optimized to obtain even better overall results.Současná legislativa tlačí výrobce vozidel k okamžité elektrifikaci pohonu, protože je to v tuto chvíli jediná možnost, jak dostát požadavkům na flotilové emise CO2. Nejběžnější formou elektrifikace pohonu jsou v dnešní době vozidla s paralelním hybridním pohonem anebo bateriové elektromobily. Nicméně hybridní pohon, na rozdíl právě od konvenčního nebo čistě elektrického pohonu, představuje zajímavé výzvy spojené s návrhem řídicího algoritmu, který musí v každém okamžiku zajišťovat optimální rozdělení výkonu mezi spalovací motor a elektromotor.Tento článek v úvodu krátce shrnuje specifické funkce a požadavky na takový řídicí algoritmus, společně s obecným přehledem možných řídicích strategií hybridních vozidel. Následně je navržena řídicí strategie kombinující heuristická pravidla se suboptimální numerickou metodou, která vypočítává parametr optimálního dělení výkonu na základě účinností spalovacího motoru a elektromotoru. Na základě navrhnuté strategie je v programu Matlab/Simulink vytvořen modulární řídicí algoritmus pro dvě paralelní hybridní topologie: P2 a P0P4, který je následně propojen s modely vozidel vytvořenými v simulačním prostředí GT-Suite a testován v homologačním cyklu WLTC. Nakonec je prezentováno několik testů řídicího algoritmu, které demonstrují úsporu paliva vybraných topologií hybridního vozidla pracujících v hybridních režimech, ve srovnání s provozem pouze v konvenčním režimu pohonu. Avšak heuristická pravidla mohou být dále optimalizována, s cílem dosáhnout ještě příznivějších celkových výsledků.

AUTONOMOUS VEHICLES AND EUROPEAN DATA PROTECTION LAW

Autonomous vehicles process a huge amount of data about the driver, or rather passengers of the vehicle, as well as about other persons (pedestrians and passengers of other vehicles). This is why the autonomous vehicles raise questions about the protection of personal data. In 2018 a new European data protection legislation came into force. The General Data Protection Regulation places new obligations on controllers of personal data and provides new rights to data subjects, which will relate to operations of autonomous vehicles and their infrastructure. The providers thereof will have to implement the principles of data protection legislation into their systems. In this context the personal data is not just data concerning the identity of the driver, a passenger or other persons, but any information relating to an identified or identifiable natural person who can be identified, directly or indirectly, in particular by reference to an identifier such as a name, an identification number, location data, or even due to a peculiar behaviour in the vehicle. The paper will focus on the new legal regulation in relation to the operation of autonomous vehicles.Autonomní vozidla zpracovávají velké množství údajů o řidiči vozidla, resp. cestujících ve vozidle, jakož i o dalších osobách (spolucestujících, chodcích a pasažérech v jiných vozidlech). To je důvod, proč provoz autonomních vozidel vyvolává řadu otázek týkajících se ochrany osobních údajů. V roce 2018 nabyla účinnosti nová evropská právní úprava regulující tuto oblast. Obecné nařízení o ochraně osobních údajů přináší nové povinnosti správcům osobních údajů, jakož i nová práva subjektům údajů, která se budou týkat provozu autonomních vozidel a infrastruktury. Výrobci a poskytovatelé služeb budou muset do svých systémů implementovat legislativu o ochraně osobních údajů. Osobními údaji nejsou pouze údaje týkající se totožnosti řidiče, cestujících nebo jiných osob, ale veškeré informace vztahujících se k identifikované nebo identifikovatelné fyzické osobě, kterou lze přímo nebo nepřímo identifikovat, zejména odkazem na identifikátor, jako je např. název, identifikační číslo, lokalizační údaje, nebo třeba i kvůli osobitému chování ve vozidle. Tento článek se zaměřuje na novou právní úpravu ve vztahu k provozu autonomních vozidel.

IN-CYLINDER FLOW CHARACTERIZATION USING VORTICITY BASED PARAMETERS

The paper deals with intake swirling flow characterization in the cylinder of IC engine. The commonly used method based on the swirl resp. tumble number from angular momentum flux evaluation does not need to give the appropriate values in some cases. Typically, in the case of two intake ports, a counter-rotating swirl vortex pair is presented. However their summary angular momentum flux is zero a thus corresponding swirl number is zero too. In order to correctly quantify these cases, it is proposed to evaluate so called vorticity numbers, i.e. dimensionless numbers based on vorticity evaluation. Concrete results are evaluated from data obtained using 3-D CFD simulation in AVL FIRE code. Comparison of variously defined vorticity numbers with each other and with the vortex numbers is performed. A practical way of calculating the vorticity numbers was also suggested with regard to possible adverse effects of the velocity gradients at the cylinder wall.

Optimization of 2‑Stage Turbocharged Gas SI Engine Under Steady State Operation

The proposed paper deals with an optimization of a highly-turbocharged large-bore gas SI engine. Only steady state operation (constant engine speed and load) is considered. The paper is mainly focused on theoretical potential of 2-stage turbocharging concept in terms of performance and limitation. The results are obtained by means of simulation using complex 0-D/ 1-D engine model including the control algorithm. Different mixture composition concepts are considered to satisfy different levels of NOx limit - fresh air mixed with external cooled EGR is supposed to be the right approach while optimal EGR level is to be found. Considering EGR circuit, 5 different layouts are tested to select the best design. As the engine control is relatively complex (2-sage turbocharger group, external EGR, compressor blow-by, controlled air excess), 5 different control means of boost pressure were considered. Each variant based on above mentioned options is optimized in terms of compressor/turbine size (swallowing capacity) to obtain the best possible BSFC. The optimal variants are compared and general conclusions are drawn.