Simulation of engagement control in automotive dry-clutch and temperature field analysis through finite element model

The tribological contact under sliding condition in the clutch facing surfaces during the engagement manoeuvre is strongly affected by heat transfer occurring in the system. The frictional forces acting on the contact surfaces produce mechanical energy losses which are converted in heat with ensuing temperature increase. Reports about the temperature rise after repeated clutch engagements prove the occurrence of interface temperature peaks as high as 300 °C. Unfortunately, only few papers address their focus towards experiments and their outcomes about the influence of temperature and the other operating parameters on the frictional behaviour of the clutch facing materials. In this paper, the Authors mainly explored the frictional behaviour modification for thermal level higher than 250–300 °C, whose effect is a sharp decline of the friction coefficient related to the decomposition of the phenol resin of the facings. Moreover, this phenomenon induces not expected transition from dry friction to mixed dry-lubricated friction which explains the reasons of the friction coefficient drop. The temperature affects also the cushion spring load-deflection characteristic and the ensuing transmitted clutch torque. Thus, an original frictional map has been implemented in a control algorithm to estimate the heat flux during vehicle launch and up-shift manoeuvres. The results of the longitudinal vehicle dynamics has been used in a FEA to predict the temperature field during repeated clutch engagement on the contact surfaces. The simulation results prove that during each engagement the interface temperature increases of 30–35 °C. This means that after only few repeated clutch engagements the temperature field could reach values near the critical point of 300 °C. In such a way, this paper aims at providing useful references to control engineers in order to improve the dry-clutch transmissions performances

Dry clutch for automated manual transmissions. Structural analysis and control strategies

2012 - 2013The goal of this thesis is the study of the automotive push-type dry clutches used in the Automatic Manual Transmissions (AMTs) and in the Dual Clutch Transmissions (DCTs) in order to improve their performances dur- ing the engagements phases. The push-type clutch is very widespread in the automotive sector because it allows many advantages in terms of cost, relia- bility, isolation of vibrations to the driveline, reduced axial size and stability to the facings wear [1]. Instead, the main advantages of an AMT, respect to the Automatic Transmissions (ATs), are improvements in terms of safety, reliability, and driving performances together with the reduction of the fuel consumption and pollutant emissions [2]. For these reasons by mixing the advantages of the push-type clutch with the advantages of the AMT it is possible to attain very high performance [3, 4]. On the other hand, the most important drawback of the AMT is the power interruption (the so called "torque gap") during the gear shifts events. To solve this problem in the last decade the DCTs have been introduced. In fact, by applying the engine torque to one clutch just as the engine torque is being disconnected from the other one [5] the torque transmission is allowed also during the gear shift phases. In this light, the work developed for this Thesis aimed at providing useful information both to the clutch designers and to control algorithm designers in order to enhance the performances, and consequently, the market di usion mof the AMT and DCT transmissions. The thesis is organized as follows. Chapter 2 is an introductory section on the historical evolution of the clutches and of the automotive transmissions systems. Chapter 3 deals with the transmissibility torque model by consid- ering the main factors which a ect the elastic components of a push-type clutch and the friction coe cient. In the Chapter 4 application of control algorithms both for a two DoFs driveline model and for a ve DoFs model are introduced. Finally, the Chapter 5 underlines the concluding remarks. [edited by author]XII n.s

Model Based Optimal Longitudinal Vehicle Control

Tez (Doktora) -- İstanbul Teknik Üniversitesi, Fen Bilimleri Enstitüsü, 2016Thesis (Ph.D.) -- İstanbul Technical University, Institute of Science and Technology, 2016Otomotiv sektöründeki zorlu rekabet ortamı göz önüne alındığında, otomotiv üreticileri müşterilerine daha çekici ve fonksiyonel araçlar sunabilmak için birbirleri ile sürekli bir yarış halindelerdir. Maliyet, emisyon, yakıt ekonomisi, gürültü ve titreşim, dayanıklılık, performans ve araç sürüş özellikleri gibi kriterlerde yapılan iyileştirmeler sayesinde üreticiler rakip firmaların araçlarına göre daha avantajlı bir yere gelmeyi hedeflerler. Bu özelliklerin her biri müşterilerin kullandığı / kullacağı araç için olumlu bir algı oluşturulmasında önemli katkısı vardır. Bilişim ve elektronik sektöründeki araştırma ve gelişmeler faaliyetleri sonucunda elde edilen yeni teknolojiler ışığında otomobil mimarisindeki elektro-mekanik istemlerin kullanımı oldukça artmıştır. Buna ek olarak malzeme bilimi ve üretim teknolojisinde gelişmeler ışığında dizel yakıtlı içten yanmalı motorlarun tork ve güç eğrileri 20 yıl önce üretilen motorlardaki tork ve güç seviyelerine göre neredeyse 2 katına çıkmıştır. Ayrıca araçların ivmelenme manevralarındaki hızlanma tepki seviyeleri de özellikle hava yolu kontrolündeki yenilik ve gelişmeler doğrultusunda oldukça artmıştır ve araçları çok daha çevik ve sürücülerin gaz pedalı hareketine bağlı isteklerine çok daha fazla duyarlı hale getirmiştir. Motor tork ve güç kapasitelerindeki gelişmeler doğrultusunda araçların gaz pedalı tepkileri ciddi oranda değişmiş ve iyi bir araç sürüş özellikleri kalibrasyonuna ihtiyaç doğmuştur. Tüm gelişmelerin neticesinde araç sürüş özellikleri, müşteri memnuiyeti kriterleri arasında önemli bir paya sahip olmuştur. Bu tez çalışması araç sürüş üzellikleri simulasyon programları ve model bazlı kontrol algoritmaları kullanarak iyileştirmeyi amaçlamaktadır. Aracın güç ünitesi olan motorlardan tekerlekler vasıtasıyla yola olan tork ve kuvvet iletimi son derece karmaşık bir yapıya sahiptir ve araç sürüş özellikleri düşünüldüğünde dikkatli bir şekilde ele alınmalıdır. Aracın gaz pedalı hareketine olan tepkisi gecikme içermemeli, yeteri kadar hızlı ve seri olmalı aynı zamanda vurma, sarsıntı, salınım ve yığılma gibi hata modları içermemelidir. Bununla birlikte araç aktarma organları bileşenlerindeki doğrusal olmayan sistemler düşünüldüğünde, yukarıda bahsedilen araç sürüş özellikleri beklentilerini karşılamak son derece zorlu bir hal almaktadır. Eski araçlardaki gaz pedalı ve kelebeği arasındaki bağlantı teli vasıtasıyla sağlanan mekanik araç doğrusal ekseni kontrolünden farklı olarak, günümüzün modern araçları elektromekanik sistemler ile donatılmıştır. Motor kontrol üniteleri araç dorusal ekseni hareketini regülatif ve müşteri beklentileri ile uyumlu şekilde sağlamak için onlarca sensör sinyalini algıladıkdan sonra milisaniyeler içersinde işleyerek, motor ve araç aktüatörlerinin kontrolü için uygun sinyalleri üretirler. Araç sürüş özellikleri algoritmları düşünüldüğünde otomobil üreticileri gaz pedalı deplasmanına bağlı sürücü tork isteğini yumuşatan veya filtreleyen algorithmalar kullanırlar. Bu algoritmalar genellikle harita bazlıdırlar ve ana misyonları özellikle araç aktarma organlarındaki dişli mekanizmalarındaki boşluklardan geçerken geçerken tork artış ve azalma hızlarını limitleyerek araç sürüş özelliklerini iyileştirmektir. Sistem herhangi bir kapalı döngü içermediği için, bu algoritmalar subjectif kalibrasyon yöntemleri olarak tanımlanabilirler ve sistemin doğru çalışması, bu haritaları kalibre edem kalibrasyon mühendisinin hislerine ve yeteneğine bağlıdır. Ayrıca bu haritalardaki araç hızı, pedal pozisyonu ve vitese bağlı kombinasyonlar içerirler ve tüm olası koşulları içeren bir kalibrasyon yapılması oldukça zaman almaktadır. Mevcut kalibrasyon yapısının yukarıda bahsedilen kusurları göz önüne alındığında; araç sürüş özelliklerinin iyileştirilmesi için performans ve konfor gibi birbirleriye çelişen isteklerin optimizasyonunu barındıran gelişmiş tork kontrolü, otomobil üreticileri ve akademik dünyada son derece ilgi çeken bir konu haline gelmiştir. Araç doğrusal ekseni hareket kontrolü algoritmalarının başarılı bir şekilde kullanılabilmesi için motorun anlık olarak ürettiği torkun bilinmesi oldukça önemlidir. Günümüz araçlarının yanma kontrolü incelendiğinde, mevcut yapının harita bazlı olduğu görülür ve bu yapıda üretilen torkun doğrulaması yapılmamaktadır. Bu haritalar motor test dinamometrelerinde normal hava koşulları için (25 derece sıcaklık ve deniz seviyesi irtifa) doldurulurlar. Genellikle bu haritaların eksenleri motor hızı ve istenilen indike tork şeklinde olup, haritanın içeriğini ise istenilen yanma parametresinin belirtilen motor hızı ve indike torktaki değeri oluşturur. Bu yapı araçlarda kullanılırken bazı sıkıntılar yaratabilir. Motorlarda yanmayı oluşturan yakıt yolu parametreleri kontrolü çok daha hassas bir şekilde yapılırken (istenilen yakıt özellikleri: basınç, zamanlama ve miktar), gecici rejim manevraları düşünüldüğünde hava yolu parametreleri özellikle turbo şarj içeren dizel motor motorlarda istenilen değerden sapma gösterebilir. Bu durum “turbo gecikmesi” olarak adlandırılır ve üretilen torku ciddi şekilde etkiler. Aşırı sıcak yada soğuk ve yüksek irtifa koşulları düşünüldüğünde üretilen torktaki sapmalar çok daha fazla olur. Literature incelendiğinde araç eksenel doğrultusu için geliştirilen motor tork kontrol algoritmaları bakımından istenilen anlık torkun motor tarafından verildiği düşünülür. Fakat yukarıda belirtilen nedenlerden dolayı bu durum gerçekleşemez. Bu yüzden literaturde belirtilen araç doğrulsal ekseni için geliştirilen motor tork kontrolü algoritmalarında motor tork karakteristiği ya hiç düşünülmemiştir yada bazı temel gecikme ve filtrele fonksiyonları ile modellenmiştir. Tüm bu anlatılanlar düşünüldüğünde bu tez çalışmasının temelini oluşturan motor tork modeli içeren araç doğrusal ekseni kontrol algoritması literatürdeki diğer çalışmaşlarda ayrışır. Önerilen “Silindir için basınç öngörümlü motor tork kontrol modeli algoritması” araç sürüş özellikleri kontrol yapısı ile uyumlu bir şekilde çalışarak araç tepki karakterini iyileştirir. Bu çalışma kapsamında MATLAB/Similink modelle ortamında, 4 atalet kütlesi, 2 set yay ve sönüm elemanı ve lastik karakteristiği içeren, 4 serbbestlik dereceli bir aktarma organları modeli oluşturulmuştur. Sadece araç doğrusal ekseni araç dinamiğini içeren model validasyonu, gaz basma ve gazdan çekme gibi yük değişimi manevralarını içeren araç seviyesi tesler ile yürütülmüştür. Test ölçüm sonuçları ve model çıktıları karşılaştırıldığında geliştirilen aktarma organları modelinin araç doğrusal ekseni hızlanma profili için karşılaşılan hata modlarını da içerecek şekilde yansıttığı görülmüştür. Son olarak araç aktarma organları uygulaması düşünüldüğünde, araç sürüş özelliklerini iyileştirme için sürücü talebi doğrultusunda oluşan tork isteğini araç doğrulsal ekseni hareketinde oluşabilecek salınımları engelleyen model bazlı öngörümlü tork kontrol algoritması geliştirilmiştir. Bu algoritmada 4 serbestlik dereceli model, içerdiği doğrusal olmama durumu yüzünden kullanılamamıştır. Bu yüzden basitleştirilmiş 2 ve 3 serbestlik dereceli araç aktarma organları modelleri oluşturulmuştur. Yapılan çalışmalar doğrultusunda hem 2 hem de 3 serbestlik dereceli modellerin, model bazlı öngörümlü tork kontrol algoritmasını düzgün şekilde çalıştırabilmek için yeterli doğruluk ve çözünürlükde olduğu görülmüştür. Bu çalışmanın amacı kapalı devre bir araç sürüş özellikleri algoritması ortaya çıkarmak olduğu için ve geliştirilen algoritma teknik nedenler dolayısıyla araçta denenemediği için, 4 serbestlik dereceli motor aktarma organları modeli, 2 ve 3 serbestlik dereceli motor aktarma organları modelli içeren model bazlı öngörümlü tork kontrol algoritmalarını çalıştırmak üzere kullanılmıştır. Geliştirilen 2 ve 3 serbestlik dereceli modellerin araç sürüş özellikleri önemli derecede iyileştirdiği görülmüştür. Özellkile ivmelenme profilinin düzgünlüğü ve neden olusan sistem gecikmesi düşünüldüğünde 2 serbestlik dereceli aktarma organları modeli bazlı kontrol algoritmasnın daha iyi sonuç verdiği görülmüştür. Geliştirilen tork kontrol modelli aktarma organları bazlı araç salınımları ciddi oranda azaltsada, tamamen ortadan kaldırmadığı görülmüştür. Bu doğrultuda araç ivmelenme karakteristiğinden minimum seviyede ödün vererek, oluşan salınımları daha da azaltmak ve ivmelenme profilini daha düzgün hale getirmek için temel olarak motor ve araç hızı farkını elimine etme prensibine dayanan bir doğrulsal (P) kontrolcü, model bazlı öngürümlü tork kontrol algoritmasına eklenmiştir. Literatürde bu konuda yapılan çalışmalar incelendiğinde tüm araçtırmacıların model bazlı öngürümlü algoritmayı tek başına kullandıkları görükmektedir ve bu çalışmada önerilen doğrusal kontrolcü eklenmiş model bazlı öngörümlü tork kontrol algoritması bir yenilik olarak mevcut literatür içeriğine eklenmiştir.Considering the competitive environment in automotive industry, original equipment manufacturers (OEMs) in this industry are in a challenging competition with each other to offer their customers more attractive vehicles. Cost, emissions, fuel economy, noise vibration & harshness (NVH), durability, performance and driveability properties make a product able to distinguish from its competitors’ products. Each of these attributes has a major contribution of forming a perception of the customers’ choosiness. New technologies as a result of the research and developments activities in electronics resulted with complex electro-mechanical systems in automobiles. With the addition of recent developments in materials and manufacturing processes on top of it, especially in diesel fuelled internal combustion engines (ICE), torque and power delivery had almost doubled with respect to the conventional engines developed not more than two decades ago. Additionally as a result of latest developments at air path and gas exchange systems control, torque build up rate had significantly increased enabling the vehicles to be more agile and reactive to load change request manoeuvres. As a result of all these capability improvements, vehicle response characteristics to high torque and power capacity engines changed extremely altering the necessity of proper and robust driveability calibration requirements. Driveability properties of the vehicles had gained significant importance in terms of customer satisfaction. This dissertation focuses on improving vehicle driveability properties taking advantage of simulation tools and model based control. The overall profit of this thesis is providing improved driveability via using engine torque production and vehicle models and controllers at the same time. Torque transmission from the vehicle’s power unit to the road surface via tires is a complex structure which should be handled with extreme care considering the overall driveability performance of the vehicle. An agile throttle response of the vehicle is aimed without error modes like acceleration initial kick, bump, response delay, stumble or shuffle. However considering the nonlinearities resulting from the complex structures at the drivetrain of the vehicle, this requirement becomes significantly challenging. Despite mechanical control at longitudinal motion in conventional vehicles, modern vehicles are equipped with electromechanical systems. Thanks to technological developments in the automotive industry that current capability of the vehicles enables us to develop better platforms for improving driveability characteristics. Modern engine control units (ECUs) have the capability of processing thousands of signals in a less than tens of milliseconds and as a result regulate numerous actuators which results with displacement of the vehicle complying all regulative requirements and customer expectations. Acceleration throttle pedal input signal is recorded by electronic control unit, processed and finally used to control the parameters for the combustion systems. In terms of driveability control, automotive manufacturers’ engine control algorithms employ input shaping or simple filtering algorithms. These algorithms use look-up tables and main control strategy is to slew the pedal oriented torque request for the tip-in and tip-out manoeuvres in an open loop control methodology especially in backlash transition region of the driveline. Considering the fact that there is no close loop control and these features become subjective calibration methodologies and outcome becomes strongly dependant on calibrator’s capability and performance. Moreover filling look-up tables for all gear, engine speed and pedal position combinations requires significant amount of calibration development time. Taking into consideration all of these obstacles of the current driveability features, the subject of automated torque control for improved driveability is a state of the art research topic both within automotive manufacturers and academic researchers as it can be described as an optimization problem dealing with performance and comfort counter measures. Knowledge of the instantaneous produced torque by the engine is a key item with respect to satisfying above stated attributes in vehicle longitudinal motion control. Currently common approach for combustion management is the usage of look-up table based structures with the drawback of poor conformity of the produced torque. Look-up tables define air and fuel quantity setpoints in order to produce requested indicated torque without feedback of the produced torque. These look-up tables are filled at engine dynamometer test benches at normal ambient conditions. In general fuel and air quantity setpoint maps have the axes of engine speed and indicated torque and requested amount of desired variable is filled to the corresponding point of the look-up table. In real world driving conditions fuel quantity control is robust however especially with turbocharged systems; requested air quantities may deviate from the setpoint values especially when considering transient manoeuvres. This phenomenon is called “turbo/boost lag” and significantly affects the produced torque. The situation is much worse for non-standard conditions, extreme hot and cold and altitude. In the literature most of the proposed vehicle longitudinal motion control related engine torque control algorithms base on the fact that requested torque will be generated immediately from the diesel engine. However as explained above this is not the case in real life applications. Therefore engine characteristic is either not included or covered with a simple filtering algorithm in conventional vehicle longitudinal motion related engine torque control methodologies. Engine brake torque model combined driveability control algorithm proposed in this thesis is differentiated from the previous studies in the literature within this perspective. Proposed “In cylinder pressured based engine brake torque model algorithm” works in harmony with the driveability control structure and improves overall vehicle response characteristics. Within the scope of this study a 4 degree of freedom powertrain model consisting of 4 inertias, 2 set of spring and damper elements with tyre characteristics, is built in MATLAB/Simulink environment. Model validation considering longitudinal vehicle dynamics is performed with employing vehicle level tests using a tip-in followed by a tip-out acceleration pedal signal input load change manoeuvres. Comparison of simulation results and measured vehicle test data shows that proposed model is capable of capturing vehicle acceleration profile revealing unintended error states for the specified input signals. Considering the driveability control perspective, a Model Predictive Control (MPC) algorithm employed to manipulate the pedal map oriented torque demand signal in an automotive powertrain application in order attenuate the powertrain oscillations in longitudinal vehicle motion control. 4 mass model could not be employed at with the MPC algorithm due to very high level of nonlinearity. Therefore two simplified versions of 2 and 3 mass models have been developed. It has been verified that both 2 and 3 mass vehicle models are accurate enough to employ the MPC torque control algorithm. As the aim of this study is to develop a close loop driveability algorithm for real world applications, the 4 mass vehicle model is used as replacement environment for the subjected vehicle in order to employ 2 and 3 mass vehicle model based control algorithm. MPC algorithms via using both models showed good capability, however smoothness of the driving profile with the 2 mass vehicle model is slightly better than the 3 mass model. Moreover to further improve the powertrain oscillations without compromising from overall system response speed, an additional anti-shuffle control element, basically a P controller based on the speed difference of engine and vehicle speeds, has been implemented to the MPC control algorithm. Literature review about the engine torque control for improved driveability show that all the researcher use MPC alone. Proposed MPC with additional P controller is a new contribution to the literature in the subjected area of research.DoktoraPh.D

Development and experimental validation of a low-frequency dynamic model for a Hybrid Electric Vehicle

This paper describes the development and experimental validation of a high-fidelity Hybrid Electric Vehicle (HEV) simulator that enables testing and calibration of energy management and driveline control strategies. The model is capable of predicting longitudinal vehicle responses that affect energy consumption and drivability in the low-to-mid frequency region (up to 10 Hz). The simulator focuses primarily on the drivetrain dynamics, while the dynamics of the actuators are represented by simplified models. The vehicle simulator is validated by a number of experiments that include electric only, engine only and hybrid operating conditions. The test vehicle has a through-the-road parallel hybrid architecture that utilises a dual electric machine configuration. Experimental results confirm that important driveline phenomena such as shunt, shuffle, torque holes and other transient disturbances related to operating mode changes are accurately predicte

Power transmission systems: from traditional to magnetic gearboxes

L'abstract è presente nell'allegato / the abstract is in the attachmen

Multi-body dynamics in vehicle engineering

Since Euler's original gyro-dynamic analysis nearly two and a half centuries ago, the use of multi-body dynamics (MBD) has spread widely in application scope from large displacement rigid body dynamics to infinitesimal amplitude elastodynamics. In some cases, MBD has become a multi-physics multi-scale analysis, comprising contact mechanics, tribo-dynamics, terramechanics, thermodynamics, biomechanics, etc. It is an essential part of all analyses in many engineering disciplines, including vehicle engineering. This paper provides an overview of historical developments with emphasis on vehicle development and investigation of observed phenomena, including noise, vibration and harshness. The approach undertaken is comprehensive and provides a uniquely focused perspective, one which has not hitherto been reported in the literature

Investigation of all-wheel-drive off-road vehicle dynamics augmented by visco-lock devices

A peculiarity of AWD off-road vehicles is that their behaviour depends not only on the total power, provided by the engine, but also on its distribution among the drive axles/wheels. In turn, this distribution is largely regulated by the drivetrain layout and its torque distribution devices. At the output of the drivetrain system, the torque is constrained by the interaction between the wheels and the soft soil. For off-road automotive applications, the design of drivetrain systems has usually been largely dominated by the mobility requirements. With the growing demand to have a multipurpose on/off road vehicle with improved manoeuvrability over deformable soil, particularly at higher speed, the challenges confronting vehicle designers have become more complex. The thesis presents a novel integrated numerical approach to assess the dynamic behaviour of all-wheel-drive vehicles whilst operating over deformable soil terrain. [Continues.

Compendium in Vehicle Motion Engineering

This compendium is written for the course “MMF062 Vehicle Motion Engineering” at Chalmers University of Technology. The compendium covers more than included in that course; both in terms of subsystem designs and in terms of some teasers for more advanced studies of vehicle dynamics. Therefore, it is also useful for the more advanced course “TME102 Vehicle Modelling and Control”.The overall objective of the compendium is to educate vehicle dynamists, i.e., engineers that understand and can contribute to development of good motion and energy functionality of vehicles. The compendium focuses on road vehicles, primarily passenger cars and commercial vehicles. Smaller road vehicles, such as bicycles and single-person cars, are only very briefly addressed. It should be mentioned that there exist a lot of ground-vehicle types not covered at all, such as: off-road/construction vehicles, tracked vehicles, horse wagons, hovercrafts, or railway vehicles.Functions are needed for requirement setting, design and verification. The overall order within the compendium is that models/methods/tools needed to understand each function are placed before the functions. Chapters 3-5 describes (complete vehicle) “functions”, organised after vehicle motion directions:\ub7\ua0\ua0\ua0\ua0\ua0\ua0\ua0\ua0 Chapter 3:\ua0Longitudinal\ua0dynamics\ub7\ua0\ua0\ua0\ua0\ua0\ua0\ua0\ua0 Chapter 4:\ua0Lateral\ua0dynamics\ub7\ua0\ua0\ua0\ua0\ua0\ua0\ua0\ua0 Chapter 5:\ua0Vertical\ua0dynamicsChapter 1 introduces automotive industry and the overall way of working there and defines required pre-knowledge from “product-generic” engineering, e.g. modelling of dynamic systems.Chapter 2 also describes the subsystems relevant for vehicle dynamics:• Wheels and Tyre\ua0• Suspension\ua0• Propulsion\ua0• Braking System\ua0• Steering System\ua0• Environment Sensing Syste

Compendium in Vehicle Motion Engineering

This compendium is written for the course “MMF062 Vehicle Motion Engineering” at Chalmers University of Technology. The compendium covers more than included in that course; both in terms of subsystem designs and in terms of some teasers for more advanced studies of vehicle dynamics. Therefore, it is also useful for the more advanced courses, such as “TME102 Vehicle Modelling and Control”.The overall objective of the compendium is to educate engineers that understand and can contribute to development of good motion and energy functionality of vehicles. The compendium focuses on road vehicles, primarily passenger cars and commercial vehicles. Smaller road vehicles, such as bicycles and single-person cars, are only very briefly addressed. It can be mentioned that there exist a lot of ground-vehicle types not covered at all, such as: off-road/construction vehicles, tracked vehicles, horse wagons, hovercrafts, and railway vehicles.Functions are needed for requirement setting, design and verification. The overall order within the compendium is that models/methods/tools needed to understand each function are placed before the functions. Chapters 3-5 describes (complete vehicle) “functions”, organised after vehicle motion directions:\ub7\ua0\ua0\ua0\ua0\ua0\ua0\ua0\ua0 Chapter 3:\ua0Longitudinal\ua0dynamics\ub7\ua0\ua0\ua0\ua0\ua0\ua0\ua0\ua0 Chapter 4:\ua0Lateral\ua0dynamics\ub7\ua0\ua0\ua0\ua0\ua0\ua0\ua0\ua0 Chapter 5:\ua0Vertical\ua0dynamicsChapter 1 introduces automotive industry and the overall way of working there and defines required pre-knowledge from “product-generic” engineering, e.g. modelling of dynamic systems.Chapter 2 also describes the subsystems relevant for vehicle dynamics:• Wheels and Tyre\ua0• Suspension\ua0• Propulsion\ua0• Braking System\ua0• Steering System\ua0• Environment Sensing SystemThe compendium is released in a new version each year, around October, which is the version your read now. A "latest draft" is more frequently updated and often includes some more, sometimes unfinished, material: https://chalmersuniversity.box.com/s/6igaen1ugcjzuhjziuon08axxiy817f

A Study on the Integration of a High-Speed Flywheel as an Energy Storage Device in Hybrid Vehicles

The last couple of decades have seen the rise of the hybrid electric vehicle as a compromise between the outstanding specific energy of petrol fuels and its low-cost technology, and the zero tail-gate emissions of the electric vehicle. Despite this, considerable reductions in cost and further increases in fuel economy are needed for their widespread adoption. An alternative low-cost energy storage technology for vehicles is the high-speed flywheel. The flywheel has important limitations that exclude it from being used as a primary energy source for vehicles, but its power characteristics and low-cost materials make it a powerful complement to a vehicle's primary propulsion system. This thesis presents an analysis on the integration of a high-speed flywheel for use as a secondary energy storage device in hybrid vehicles. Unlike other energy storage technologies, the energy content of the flywheel has a direct impact on the velocity of transmission. This presents an important challenge, as it means that the flywheel must be able to rotate at a speed independent of the vehicle's velocity and therefore it must be coupled via a variable speed transmission. This thesis presents some practical ways in which to accomplish this in conventional road vehicles, namely with the use of a variator, a planetary gear set or with the use of a power-split continuously variable transmission. Fundamental analyses on the kinematic behaviour of these transmissions particularly as they pertain to flywheel powertrains are presented. Computer simulations were carried out to compare the performance of various transmissions, and the models developed are presented as well. Finally the thesis also contains an investigation on the driving and road conditions that have the most beneficial effect on hybrid vehicle performance, with a particular emphasis on the effect that the road topography has on fuel economy and the significance of this