Lidé na fakultě
Ing. Jolana Heřmanová

2024, Sborník abstraktů Konference studentské tvůrčí činnosti STČ 2024, Praha, Fakulta strojní), p. 26-26)

Traffic fluency has a major influence on vehicle energy consumption. Unfortunatelly the higher the traffic density, the higher is a probability of a traffic congestions, and with that the energy consumption of conventional vehicles increases. This paper aims to assess the effects of congested and non-congested urban traffic on various vehicle powertrains, particularly the conventional vehicles with internal combustion engine, hybrid electric vehicles and battery electric vehicles. The drive cycles of congested and uncongested traffic were derived from measurement in a city traffic, vehicle models were built in GT-Suite software and vehicle driving simulations in various driving conditions were performed. The results show the main differences in the energy consumption of simulated powertrains in dependance on the driving cycle.

Abstrakt ve sborníku z fakultní konference cizojazyčně

2024, Driver-Car Interaction and Safety Conference 2023, Praha, České vysoké učení technické v Praze), p. 14-21), ISBN 978-80-01-07387-2, ISSN 2336-5382

Most electric vehicles have a single-speed transmission as the traction characteristic of electric motor allows operation with sufficient motor torque at low and high speeds. The selection of the single-gear ratio is a trade-off between available torque for acceleration (or gradability) at lower speeds and designed maximum vehicle speed corresponding to electric motor’s maximum speed limit. Nevertheless, multiple-speed transmission can be used, and vehicle can benefit from improved acceleration at low speeds and higher maximum speeds. In this paper, the gear ratio of a single-speed transmission for an electric racing motorcycle is optimized to achieve a trade-off between acceleration, lap time, and maximum speed. With the same goal, the gear ratios for two-speed transmission are optimized, and the results are compared.

Stať ve sborníku z prestižní konf. (Scopus)

2023

In the scope of the Motostudent 2023/24 competition there was created complex project of the whole motorcycle in the category of Electro bikes. Report contains conceptual design, detailed design, prototyping and development.

Oponovaná technická zpráva cizojazyčně

2023

In the scope of the Motostudent competition there was created complex project of the whole motorcycle in the category of Electro bikes. Report economical assessemen, industrial production plan and mannagement plan of the team.

Oponovaná technická zpráva cizojazyčně

2022

V rámci urychlení zavádění nízkoemisních vozidel do vozových parků evropských subjektů byla 20. června 2019 schválena směrnice (upravující směrnici 2009/33/ES o podpoře čistých a energeticky účinných silničních vozidel), která ukládá členským státům do svých právních řádů transponovat nové podmínky pro zadávání veřejných zakázek veřejnými zadavateli. Směrnice udává povinnost minimálního podílu nízkoemisních vozidel na celkovém počtu nakupovaných vozidel v období do roku 2025 a do roku 2030. Pravidla byla dočasně do českého právního řádu transponována ve formě usnesení vlády, a poté novým zákonem o podpoře nízkoemisních vozidel (projednávaným v průběhu roku 2022). Vzhledem k tomu, že Ředitelství silnic a dálnic ČR je příspěvkovou organizací zřízenou ministrem dopravy a spojů, bude se na ni nový zákon vztahovat. Cílem této studie je navrhnout dlouhodobou koncepci obměny vozového parku Ředitelství silnic a dálnic ČR (ŘSD) s ohledem na zajištění provozuschopnosti/akceschopnosti flotily pro plnění úkolů ŘSD a zároveň splňující legislativní požadavky týkající se nákupu nízkoemisních vozidel.

Technická zpráva v češtině

2022

Technical report describing tech details of the motorcycle EVO 2.0 Electric for the competition Moto Engineering Italy in 2022 according to the regulations of Motorsport Engineering Society.

Technická zpráva cizojazyčně

2021, Sborník přednášek - 52. Mezinárodní vědecká konference českých a slovenských univerzit a institucí zaměřená na výzkumné a výukové metody spojené se spalovacími motory, alternativními pohony a dopravou, Praha-Suchdol, Technická fakulta), p. 97-109), ISBN 978-80-213-3132-7

The main purpose of 12 V onboard electric network is to power several key vehicle systems and number of other onboard consumers. For this purpose, the Internal Combustion Engine Vehicles (ICEVs) are equipped with an alternator and a 12 V battery. As the number of vehicle systems and control units in vehicle is increasing and the start-stop system is widely implemented, much higher demands are placed on the alternator and 12 V battery. With stricter limits on CO2 emissions, it is necessary to focus on the 12 V network power supply strategy. The aim of this work is to compare several approaches to powering the onboard network. The first variant is a strategy of maintaining a constant voltage of the 12 V battery. The second variant distinguishes several voltage targets for different driving modes based on the actual SOC, Internal Combustion Engine (ICE) speed and actual required power necessary to drive the vehicle. For this purpose, a 1D simulation model of a conventional car was built in the SW GT-Suite, charging strategies were implemented and the effects on fuel consumption were compared.

Stať ve sborníku z mezinár. konf. cizojazyčně

2021, ISBN 978-80-01-06894-6

Kniha České vozy velkých cen se věnuje historii automobilových soutěží a závodů a strojům, které se těchto klání účastnily, se zaměřením na vozy vyvinuté a postavené na území České republiky. První část knihy je věnována historii velkých cen obecně, evoluci pravidel a technických a bezpečnostních omezení. Druhá část knihy se zabývá známými i zapomenutými závodními vozy, které vznikly na českém území, ať jde o tovární speciály, či prototypy nadšenců. Třetí častí je katalog českých vozů velkých cen, které byly vystaveny na stejnojmenné výstavě pořádané Fakultou dopravní ČVUT v roce 2017, včetně jejich popisu a závodních úspěchů.

Vědecká kniha česky

2021, Proceedings of the FISITA 2021 World Congress, London, FISITA - International Federation of Automotive Engineering Societies), ISBN 978-1-9160259-2-9

The current legislation requires the increasing levels of vehicle powertrain electrification or hybridization to fulfill the limits of green-house gas emissions. Parallel hybrid electric vehicle (HEV) powertrain 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 plug-in capability. A more “HEV-tailored” approach merges a dedicated hybrid transmission (DHT), an ICE, a gearbox, and one or more electric motors more closely together, reducing HEV powertrain’s mechanical complexity and costs. This paper investigates a multi-mode HEV with a DHT and two electric machines with optional electric serial or parallel operating modes. Great challenge in the development of the multi-mode HEV topology with DHT is the component sizing: ICE, electric machines, and battery with optimized capacity, and yet fulfilling several roles. On one hand, satisfactory responsiveness on a dynamic driving demands (vehicle acceleration capabilities, top speed etc.). On the other hand, energy consumption achieving better levels than standard parallel HEV topologies. Added challenge is the interaction of a powertrain supervisory energy management strategy with overall DHT layout and its components, with effects on vehicle energy consumption. Our paper addresses these challenges using multi-parametric optimization workflow, that combines parametric HEV models, with optimal energy management strategy, and optimization software. The main parametric HEV model of the chosen multi-mode DHT powertrain is programmed in Python, with an optimal energy management strategy based on Pontryagin’s Minimum Principle, the second model is a 1D longitudinal vehicle dynamics model in GT-Suite multi-physics CAE system simulation software. The workflow is then used to evaluate the optimal component sizing for two different vehicle segments and fuel economy in a homologation driving cycle WLTC.

Stať ve sborníku z mezinár. konf.

2020, MECCA Journal of Middle European Construction and Design of Cars, 17 (2), p. 21-35), ISSN 1214-0821

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.

Článek v odborném recenzovaném periodiku cizojazyčně

2020

In the scope of the Motostudent competition there was created complex project of the whole motorcycle in the category of Electro bikes. Report economical assessemen, industrial production plan

Technická zpráva cizojazyčně

2020

In the scope of the Motostudent competition there was created complex project of the whole motorcycle in the category of Electro bikes. Report contains conceptual design, detailed design, prototyping and development.

Technická zpráva cizojazyčně

2018

In the scope of the Motostudent competition there was created complex project of the whole motorcycle in the category of Electro bikes. Report contains conceptual design, detailed design, prototyping, economical assessemen, industrialproduction plan and technological innovation.

Oponovaná technická zpráva cizojazyčně

2018

In the scope of the Motostudent competition there was created complex project of the whole motorcycle in the category of Petrol bikes. Report contains conceptual design, detailed design, prototyping, economical assessemen, industrialproduction plan and technological innovation.

Oponovaná technická zpráva cizojazyčně

2017, ISBN 978-80-01-06367-5

The book presents basic information about all exhibits on display and brings a lot of new information, often have not been published before. The first part of the book deals with car body types, especially roofless (cabriolets, phaetons etc.) presented in its historical view. It discusses the topics like design, aesthetics and engineering and relation of all of them to the vehicle safety. There is also unique list of Czechoslovak car and coachwork manufacturers. The second part is the catalogue of exhibited vehicles, their photos and their brief history (from manufacture through renovation to present usage).

Vědecká kniha cizojazyčně

2017, ISBN 978-80-01-06082-7

Kniha Český kabriolet a kupé v průběhu století, katalog výstavy r. 2016 podává základní informace o jednotlivých vystavených exponátech a přidává k nim další, často zatím nepublikované informace. V první části publikace je rozebrán historický vývoj všech typů karoserií osobních automobilů s důrazem zejména na otázky bezpečnosti. Kniha nabízí unikátní seznam československých výrobců vozů a karoserií v průběhu sta let. Dále se věnuje tématům konstrukce kabrioletů a designu. Druhou část tvoří samotný katalog - kompletní seznam vystavených exponátů s fotografiemi a historií jednotlivých vozů.

Vědecká kniha česky