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This paper presents a high-fidelity electro-thermal model of a half-bridge that consists of IGBTs and anti-parallel diodes. The model calculates and estimates the half-bridge voltages, currents, switching and conduction losses considering the operating temperature and current conditions. Moreover, this model is suitable for varying switching frequency operation. The electro-thermal model can be used as an evaluation tool to analyze the performance of control strategies for traction inverter from efficiency, temperature and component stress point of view. In this paper performance of Direct Torque Model Predictive Control (DTMPC) of an Interior Permanent Magnet Synchronous Motor (IPMSM) is evaluated in comparison with Indirect Field Oriented Control (IFOC) with sinusoidal pulse width modulation (PWM). The inverter model and the MPC are both implemented in C-Mex for rapid execution. The MPC algorithm implemented in this research tracks torque reference while using Maximum-Torque-Per-Ampere (MTPA) strategy and minimizing switching losses. Both control systems are able to follow the speed reference. The MPC shows a decrease in losses compared to IFOC when tested with low-speed and high-speed parts of the WLTC profile.

International audience; Global warming has put the transport sector, a major contributor of CO 2 emissions, under high pressure to improve efficiency. In this context, ultra-light vehicles weighting less than 500 kg, as well as hybrid powertrains, are nowadays seen as promising development trends. The design process of the powertrain of a vehicle combining the advantages of the two concepts is presented in this paper. Through a performance study based on a simple MATLAB model, and mathematical simulation, a proposal is made. A powertrain using a battery and supercapacitor 48V dual power source network, two electric motors and clutches to switch between conventional, parallel, series and full electric modes proves to be an interesting system in terms of performance and costs. A simulation study conducted on a scenario with different outcome possibilities showed that high modularity of the system allows to achieve fuel efficiencies equivalent to approximately 3 l/100 km on the Artemis cycle. Finally, integration, packaging and cost are considered and some hints for further powertrain efficiency improvements are presented.

It has been predicted that the prevailing COVID-19 situation would result in increased demand for personal vehicles. There is a renewed interest in the 3 wheeled vehicles for short urban mobility in western countries due to their inherent cost advantages which will make it affordable for the common man. As the world is moving towards electric vehicle technology, a light 3 wheeled vehicle option will also help in reducing battery weight and thereby help in addressing the range concerns. In addition, slow speed 3-wheelers need not pass extensive safety regulation tests in many western countries including the USA. Three-wheeled vehicles are not new to developing countries like India as three-wheeled auto-rickshaws are quite popular for short distance shared travel. The existing single front wheel design known as delta design may have a stigma attached to it due to historic reasons in India. There is also a perception that the three-wheeled vehicles are highly unstable. Therefore, the current paper studies in detail an alternate design known as the tadpole design having two wheels in the front. The tadpole configuration facilitates decent styling and good aerodynamics. The tadpole configuration is modeled and analyzed using CAE multibody dynamics software, MSC Adams Car. To get confidence in the simulation results, a few benchmarked and tested vehicles are selected from the available literature [1] and the MBD results are compared for correlation. The studies also include a standard four-wheeled vehicle and a delta configuration 3-wheeler for reference purpose. The MBD virtual analyses provide results for vehicle stability and handling characteristics like overturning speed limit, oversteer and understeer behavior during constant radius cornering tests. The paper, by keeping in mind the typical urban driving condition and pattern, gives its feedback and recommendation about the tadpole configured 3-wheeler. © 2021 SAE International. All rights reserved.

The paper deals with the reduction of pollutant emissions in urban areas by considering a Zero-Emission Zone (ZEZ) in which hybrid electric vehicles (HEVs) are allowed to be driven without using the internal combustion engine, as several cities have planned to realize in the next decades. Moreover, since vehicle connectivity has spread more and more in the last years, a vehicle-to-network (V2N) communication system has been taken into account to retrieve real-time navigation data from a map service provider and thus reconstructing the so-called electronic horizon, which is a reconstruction of the future conditions of the vehicle on the road ahead. The speed profile and the road slope are used as input for an on-board predictive control strategy of a plug-in HEV (PHEV). In particular, a dedicated algorithm predicts the amount of necessary energy to complete the city event in full-electric mode, giving a state of charge (SoC) target value. With this aim, an adaptive equivalent consumption minimization strategy (A-ECMS) has been modified to use navigation data for approaching the ZEZ with the target SoC. The paper finally quantifies the benefits of such an approach in terms of CO2 emissions by comparing it with a heuristic, rule-based one, which represents the standard OEM solution.

Battery electric vehicles (BEV) share the ability of regenerative braking since they are equipped with two independent types of deceleration devices, namely the electric motor working as a generator and the friction brakes. Correct interaction of these systems in terms of driving safety and energy efficiency is a function of the Brake Blending Control. Individual electric motors for each wheel and a decoupled brake system provides the Brake Blending with a high design flexibility that allows significant advantages regarding energy consumption, brake performance, and driving comfort. This paper is focusing on the fail behaviour and analyses the robustness and redundancy abilities of such systems against various error scenarios. For this purposes, a distributed x-in-the-loop environment, consisting of dedicated simulation and hardware testing components, is introduced. The investigation is carried out based on a high-fidelity real-time simulation model of an electric sport utility vehicle with four in-wheel motors (IWM) and decoupled electro-hydraulic brake system. This model can be used for a detailed analysis of vehicle dynamics in case of brake system fails. The electro-hydraulic decoupled brake system is implemented through a Hardware-in-the-loop test rig, which allows a realistic fault injection. The vehicle stability and controllability is investigated under the circumstances of various brake system failures in the regenerative and friction brake system, respectively. These studies are presented according to standardized test scenarios like Straight line braking (DIN 70028) and Brake-in-turn (ISO 7975). With obtained x-in-the-loop simulation results, the impact of a failure on vehicle dynamics is discussed in the final part of the paper.

This paper was commissioned for the design and analysis of an entire rear suspension system befitting a Formula Society of Automotive Engineers (FSAE) vehicle. The paper includes a literature review to gain a full understanding of the workings and design decisions applied to the rear suspension in the Society of Automotive Engineers (SAE) competition. After completing the design development process, a final analysis of the designed system was done to ensure the minimum two years-of-life requirement is met. It was found that due to constraints, a major design change was necessary that involves mounting the A-arms further forward on the chassis body than previous generation vehicles. This design increased the stresses present in the system compared to previous designs. As such, careful consid-eration had been given to the analysis aspect of the paper. Full fatigue analysis performed individually on each component proved that the lower A-arm was the most critical component, with a predicted failure at 1466 laps. However, with the given lifespan of two years, this design procured a conservative Factor of Safety of above two years.Notable mention should be given to the complete develop-ment of an FSAE uniaxial force determination code that was produced by Team Recoil. This code greatly improved the confidence in component forces and thus allowed less conservative design choices in several other aspects.

This paper conceptualizes the design of a single-seater All-Terrain Vehicle (ATV). The aim was to design and fabricate a lightweight, high strength vehicle (under 175kgs) which can withstand harsh terrains, while being affordable and easily manufacturable. This paper covers the extent of design and simulations ranging from static structural, fatigue analysis, explicit dynamics etc. have been carried out. Tools such as SolidWorks, Ansys and MATLAB have been used throughout the process.The report is divided into individual subsystems, such as Chassis, Braking, Powertrain, Suspension and Steering. All the design considerations and objectives of each of the subsystems have been included. Simulation results of various components such as the Chassis, A-arms, Knuckles, Hubs and integral mounts have been attached with focus on modelling based on real-time forces and behaviors.

This paper describes a multi-degree-of-freedom model of a three-wheeled car, implemented in Matlab®. The purpose was to investigate the dynamics of the car (assumed to be rigid on its suspension) during cornering. While the problems associated with three-wheeled cars are well-known, much of the guidance in the literature and off-the-software assumes a conventional four-wheeled car. Consequently, the authors were approached with a battery-electric concept car which was thought to offer better performance than existing variants, because the use of hub motors lowered the centre of gravity and hence reduced rollover coefficient. However, simulation of the vehicle model in cornering shows that the concept is still prone to instability. Indeed, it suffers greater roll velocities than a comparable three-wheeled car with internal combustion engine, because the ratio of sprung to unsprung mass is significantly altered. This paper therefore recommends a programme of further simulations and model-based design changes to progress the concept to a marketable performance product.

The automotive trends of vehicles with lower aerodynamic drag and more powerful drivetrains have caused increasing concern regarding stability issues at high speeds, since more streamlined bodies show greater sensitivity to crosswinds. This is especially pronounced for high vehicles, such as sports utility vehicles. Besides, the competitiveness in the automotive industry requires faster development times and, thus, a need to evaluate the high speed stability performance in an early design phase, preferable using simulation tools. The usefulness of these simulation tools partly relies on realistic boundary conditions for the wind and quantitative measures for assessing stability without the subjective evaluation of experienced drivers. This study employs an on-road experimental measurements setup to define relevant wind conditions and to find an objective methodology to evaluate high speed stability. The paper focuses on the events in proximity to the drivers’ subjective triggers of instability. Wind direction and magnitude, vehicle motion response, along with the subjective event triggering were measured at different conditions of the natural wind. A statistical approach was utilized to analyze the correlation between the vehicle response and subjective triggers together with the wind conditions. A correlation was established between the subjective triggers and a rapid change in lateral acceleration and yaw velocity response. The paper also proposes a set of four crosswind gust profiles of interest for driving stability, combining results from previous research and the experimental data of the natural wind obtained in this study. These findings can be used as objective measures for virtually assessing stability performance and as realistic boundary conditions for simulating wind gusts.

Connected vehicles (CVs) have situational awareness that can be exploited for control and optimization of the powertrain system. While extensive studies have been carried out for energy efficiency improvement of CVs via eco-driving and planning, the implication of such technologies on the thermal responses of CVs has not been fully investigated. One of the key challenges in leveraging connectivity for optimization-based thermal management of CVs is the relatively slow thermal dynamics, which necessitate the use of a long prediction horizon to achieve the best performance. Long-term prediction of the CV speed, unlike the V2V/V2I-based short-range prediction, is difficult and error-prone. The multiple timescales inherent to power and thermal systems call for a variable timescale optimization framework with access to short- and long-term vehicle speed preview. To this end, a model predictive controller (MPC) with a multi-range speed preview for integrated power and thermal management (iPTM) of connected hybrid electric vehicles (HEVs) is presented in this paper. The MPC is formulated to manage the power-split between the engine and the battery while enforcing the power and thermal (engine coolant and catalytic converter temperatures) constraints. The MPC exploits prediction and optimization over a shorter receding horizon and longer shrinking horizon. Over the longer shrinking horizon, the vehicle speed estimation is based on the data collected from the connected vehicles traveling on the same route as the ego-vehicle. Simulation results of applying the MPC over real-world urban driving cycles in Ann Arbor, MI are presented to demonstrate the effectiveness and fuel-saving potentials of the proposed iPTM strategy under the uncertainty associated with long-term predictions of the CV's speed., 15 pages, 15 figures, 1 table, to appear in 2020 WCX SAE World Congress Experience, SAE Technical Paper 2020-01-0590

This paper presents an optimization algorithm, based on discrete dynamic programming, that aims to find the optimal control inputs both for energy and thermal management control strategies of a Plug-in Hybrid Electric Vehicle, in order to minimize the energy consumption over a given driving mission. The chosen vehicle has a complex P1-P4 architecture, with two electrical machines on the front axle and an additional one directly coupled with the engine, on the rear axle. In the first section, the algorithm structure is presented, including the cost-function definition, the disturbances, the state variables and the control variables chosen for the optimal control problem formulation. The second section reports the simplified quasi-static analytical model of the powertrain, which has been used for backward optimization. For this purpose, only the vehicle longitudinal dynamics have been considered. The third section describes the Model-in-the-Loop environment of the vehicle, implemented in Simulink. In particular, the validation of the fuel consumption and the battery temperature models against experimental data is shown, and the original control strategies for the energy and thermal management are described, as well. This powertrain model is used to evaluate vehicle performance. As the powertrain architecture offers different torque split possibilities, different approaches to the powertrain control are considered, starting from the baseline rule-based controllers for both the thermal and energy management, to the combined-optimization based controllers. This paper shows a consistent fuel economy improvement due to energy management optimization, which becomes even larger if thermal management is included in the optimization algorithm.

Within the context of distributed power generation, small size systems driven by spark ignition engines represent a valid and user-friendly choice, that ensures good fuel flexibility. One issue is that such applications are run at part load for extensive periods, thus lowering fuel economy. Employing an inverter (fitted between the generator and load) allows engine operation within a wide range of crankshaft rotational velocity, therefore improving efficiency. For the purpose of evaluating the benefits of this technology within a co-generation framework, two configurations were modeled by using the GT-Power simulation software. After model calibration based on measurements on a small size engine for two-wheel applications, the downsized version was compared to a larger power unit operated at constant engine speed for a scenario that featured up to 10 kW rated power. Indeed, the downsizing concept was found to ensure an electrical efficiency improvement of around 10% at 50% load, over 30% at 20% load, and reduced fuel consumption by over 50% at lower load. The co-generation potential was also evaluated, and it resulted practically the same from full to 50% load, while at low load the larger engine featured heat recovery potential up to two times larger compared to the smaller unit.

In recent years, the More-Electric Aircraft (MEA) concept has undergone significant development and refinement, striving towards the attainment of reductions in noise and CO2 emissions, increased power transmission efficiency and improved reliability under a range of flight scenarios. The More-Electric Engine (MEE) is increasingly being seen as a key complementary system to the MEA. With this concept, conventional engine auxiliary systems (i.e. fuel pumps, oil pumps, actuators) will be replaced by electrically-driven equivalents, providing even greater scope for the combined aircraft and engine electrical power system optimisation and management. This concept, coupled with extraction of electrical power from multiple engine spools also has the potential to deliver significant fuel burn savings. To date, single or dual channel electrical power generation and distribution systems have been used in engines and aircrafts. However, with the increasing electrification of flight-critical engine auxiliaries along with the requirement for greater load transfer flexibility, a three-channel architecture should be considered. This paper investigates potential concepts for a three-channel power system architecture in an MEE system. The paper considers issues such as architecture layout and key technologies that may be considered for MEE architecture. Using an extensive database of public domain MEA/MEE power system component failure rates, a detailed fault tree analysis is then presented. This provides a quantitative comparison of dual channel and three-channel architecture candidates under the pertinent failure modes as well as showing the impact of common architecture features on system reliability and robustness. Finally, the paper concludes with a discussion of the ring busbar topology operation and power electronics technology requirements that could successfully implement a flexible and robust three-channel architecture for MEE systems.

Look ahead information can be used to improve the powertrain’s fuel consumption while efficiently controlling exhaust emissions. A passenger car propelled by a Euro 6d capable diesel engine is studied. In the conventional approach, the diesel powertrain subsystem control is rule based. It uses no information of future load requests but is operated with the objective of low engine out exhaust emission species until the Exhaust After-Treatment System (EATS) light off has occurred, even if fuel economy is compromised greatly. Upon EATS light off, the engine is operated more fuel efficiently since the EATS system is able to treat emissions effectively. This paper presents a supervisory control structure with the intended purpose to operate the complete powertrain using a minimum of fuel while improving the robustness of exhaust emissions. A supervisory controller assisted by look ahead information, and using a supervisory control interface that works in concert with low level local controllers, can make subsystems operate near optimal. The look ahead parametrized supervisory control calculates the set-points for the subsystems: Internal Combustion Engine (ICE), Lean NOx Trap (LNT) and the Selective Catalytic Reduction (SCR) based on the Emission Equivalent Fuel Consumption minimization strategy (EEFC). The controller performance is analyzed for the World wide harmonized Light vehicles Test Cycle (WLTC) and randomly sequenced WLTCs under different initial conditions. This paper extends upon the earlier work where an LNT-SCR EATS supervisory control structure was proposed that optimizes based on the EEFC strategy. The future work will focus on extending the approach to more subsystems and characterizing the look ahead information.

The paper deals with experimental testing of a natural gas fueled engine. Break Specific fuel Consumption (BSFC), Average Mass Flow Rate, Instantaneous Cylinder Pressure and some wall temperatures have been measured at some full and part load operating conditions. The results of this experimental activity, still in progress, have been used to calibrate a 1D-flow engine’s model. Then the effects of some VVA strategies have been theoretically studied through the validated model. With the aim of maximizing the full load engine’s torque, a genetic algorithm was used to calculate the optimized intake and exhaust valves timing angles. Various VVA strategies were compared at part-load in order to reduce brake specific fuel consumption.

Due to stricter emission regulations and more environmental awareness, the powertrain systems are moving toward higher fuel efficiency and lower emissions. In response to these pressing needs, new technologies have been designed and implemented by manufacturers. As a result of increasing complexity of the powertrain systems, their control and optimization become more and more challenging. Virtual powertrain calibration, also known as model-based calibration, has been introduced to transfer a part of test bench testing into a virtual environment, and hence considerably reduce time and cost of product development process while increasing the product quality. Nevertheless, virtual calibration has not yet reached its full potential in industrial applications. Volvo Penta has recently developed a virtual test cell named VIRTEC, which is used in an ongoing pilot project to meet the Stage V emission standards. The integrated powertrain system includes engine, Exhaust Aftertreatment System (EATS), and Engine Management System (EMS). The objective of this paper is to describe the essential aspects required to increase the contribution of virtual testing in powertrain calibration activities. These aspects comprise the following: Hardware-in-the-Loop (HiL) system, simulation models, and working process for joint virtual and physical testing to facilitate efficient powertrain development process. The current paper describes the design, test and verification of a calibration platform based on the requirements of the project. The future phases in the current project (Virtual Calibration at Volvo Penta) will cover validation of the platform by performing calibrations in industrial scales on the virtual system.

This paper shows the influence of different battery charge management strategies on the fuel economy of a hybrid parallel axle-split vehicle in a real driving scenario, for a vehicle control system that has the additional possibility to split the torque between front and rear axles. The first section regards the validation of a self-developed Model in the Loop (MiL) environment of a P1-P4 plug-in hybrid electric car, using experimental data of a New European Driving Cycle test. In its original version, which is implemented on-board the vehicle, the energy management supervisor implements a heuristic, or rule-based, Energy Management Strategy (EMS). During this project, a different EMS has been developed, consisting of a sub-optimal control scheme called Equivalent Consumption Minimization Strategy (ECMS), explained in detail in the second section. After that, the focus is on the evaluation of the benefits coming from different battery charge management strategies, which can be charge-sustaining, charge-depleting/charge-sustaining or charge blended, since the vehicle is a PHEV. The fuel economy improvements, using each strategy, are compared and one of them is then combined with the knowledge of future driving conditions (the so-called electronic horizon), mainly speed and altitude profiles. Therefore, the proposed controller would be ready for on-board implementation. In the last section, a sensitivity analysis that relates the results obtained with the battery capacity is carried out, to evaluate the influence of this strategic parameter on the battery charge management strategy choice. The paper shows the fuel economy potential of a physics-based approach like ECMS for a plug-in HEV, and how it can directly benefit from the prediction of future driving conditions, especially if the battery capacity is limited.

One dimensional (1D) and three dimensional (3D) simulations are widely used in technical acoustics to predict the behavior of duct system elements including fluid machines. In particular, referring to internal combustion engines, the numerical approaches can be used to estimate the Transmission Loss (TL) of mufflers, air boxes, catalytic converters, etc. TL is a parameter commonly used in almost any kind of acoustical filters, in order to assess the passive effects related to their sound attenuation. In this paper, a previous 1D-3D acoustical analysis of a commercial muffler, has been improved and experimentally validated. Features related to the manufacturing process, like the coupling of adjacent surfaces and the actual shape of components, have been noticed to heavily affect the muffler behavior. Hence, although numerical analyses are usually performed on ideal geometries (perfectly matched and shaped), schematizations utilized for acoustic simulations of real mufflers are being suggested to do not neglect these important aspects. On the other hand, for a given initial muffler design, the manufacturing process is assessed to be a critical aspect also for its remarkable effects on the acoustics. In this work, results have been carried out under different muffler operating conditions related to different mean flow velocities and presence or not of internal insulating material. 1D analyses have been performed by implementing a commercial software, solving the nonlinear flow equations which characterize the wave propagation phenomena. 1D approach has also been utilized to evaluate the fluid dynamic behavior of the studied muffler in terms of pressure drop when a mean flow is imposed. 3D results are obtained in absence of mean flow by using a commercial software based on Boundary Element approach and solving the three dimensional Helmholtz's equation. Finally, during the experimental tests, the muffler has been treated as an acoustic two-port element.

The paper summarizes the activities related to the characterization of the noise sources and related sound emission levels emitted by a single-cylinder diesel engine. A deep analysis is carried out aiming to clearly define the various noise sources, through the employment of numerical and experimental techniques. In particular, an intensimetric analysis is carried out to define a bi-dimensional noise level map around the engine. In addition, the gas-dynamic noise, at the different engine speeds, is measured through a microphone mounted near the intake and exhaust mouth. Contemporarily to the experimental activity, a theoretical one-dimensional simulation of the whole engine is also carried out. The presented one-dimensional analysis is able to characterize the wave propagation phenomena in the external ducts and provide the estimation of both engine performance and gas-dynamic noise emission too. The presented techniques allow to fully describe the noise emission behavior of the tested engine.

Internal combustion engines are the primary transportation mover for today society and they will likely continue to be for decades to come. Hybridization is the most common solution to reduce the petrol-fuels consumption and to respect the new raw emission limits. The gasoline engines designed for running together with an electric motor need to have a very high thermal efficiency because they must work at high loads, where engine thermal efficiency is close to the maximum one. Therefore, the technical solutions bringing to thermal efficiency enhancement were adopted on HVs (Hybrid Vehicles) prior to conventional vehicles. In these days, these solutions are going to be adopted on conventional vehicles too. The purpose of this work was to trace development guidelines useful for engine designers, based on the target power and focused on the maximization of the engine thermal efficiency, following the engine rightsizing concept. The originality of the present work stands in the comparison of the effectiveness of the most common strategies adopted today between two types of engine. The chosen engines for this study were modern boosted GDI engines, in line with the current automotive market, designed by CAD at the University of Bologna. 3D CFD computations of non-reacting flows were carried out by means Fire Code 2020 by AVL. The paper aimed to numerically investigate the rightsizing concept depending on the target level of power: two levels of power were chosen, 290 kW and 120 kW respectively, typical the former one of a high-power engine, the last one of an engine more devoted to efficiency purposes. The two engine bores were selected based on the common automotive solutions depending on the target power: 84 mm for the high-power engine, 75 mm for the other engine. Once fixed the bore value and pursuing the maximization of the thermal efficiency, a study on the possible geometries was performed, searching for the best stroke-to-bore ratio S/B: the long stroke engine design finds its limit in the maximum average piston speed, depending on the engine regime at maximum power. Then, the study was moved to the compression ratio increase and the adoption of over-expanded cycles, both aimed to increase the thermal efficiency. For solving the knocking issues arising from the adoption of increased compression ratio, the water injection strategy was analyzed too. Finally, some considerations were deduced on the effectiveness in applying the over-expanded cycles to the two different types of engine: the critical point to be solved is if the applicability and thus the effectiveness of the over-expanded cycles depend on the engine type.

Knock control systems based on engine block vibrations analysis are widely adopted in passenger car engines, but such approach shows its main limits at high engine speeds, since knock intensity measurement becomes less reliable due to the increased background mechanical noise. For small two wheelers engines, knock has not been historically considered a crucial issue, mainly due to small-sized combustion chambers and mixture enrichment. Due to more stringent emission regulations and in search of reduced CO2 emissions, an effective on-board knock controller acquires today greater importance also for motorcycle applications, since it could protect the engine when different fuel types are used, and it could significantly reduce fuel consumption (by avoiding lambda enrichment and/or allowing higher compression ratios to be adopted). These types of engines typically work at high rotational speeds and the reduced signal to noise ratio makes knock onset difficult to identify. The paper shows how knock-related information can be extracted both from accelerometer and acoustic signals, and how the correlation with in-cylinder pressure based indexes can be optimized using advanced signal processing algorithms and specific calibration methodologies, for a wide engine speed range. An optimization procedure that has involved all the calibration parameters that make up sound and vibration-based knock indexes, has allowed to successfully apply knock detection techniques up to 13,000 rpm. Experimental results obtained on the engine test bench are shown throughout the paper, demonstrating the feasibility of both approaches, which provide similar signal-to-noise ratio levels, and can therefore be considered as possible alternatives.

Low Carbon fuels will play a relevant role in the transportation sector contributing, over the powertrain technology progress, to mitigate global CO2 emissions. Compressed Natural Gas (CNG), mainly composed by methane, is one of the best candidate thanks to its chemical composition and to its wide diffusion and use. Blending Hydrogen in Natural Gas could represent a further step for a better CO2 footprint (considering renewable or biohydrogen) but also to optimize the combustion process, increasing the engine thermal efficiency and reducing pollutant formation. On the other hand, capability to automatically adapt the engine parameters to variable concentrations of Hydrogen in Natural Gas (in the range from 0% to 40% by volume) is a mandatory step to maintain engine performance, emissions and efficiency The activities described in this paper are part of a large collaborative project, “Biomethair”, funded by Regione Piemonte, where material specifications on gas tanks, valves, feeding lines, gas pressure regulator, engine pipes and injectors have been set and prototype components procured and implemented into the demonstrator vehicle to ensure safe operating conditions. In this paper a software algorithm is presented, able to provide, during normal car operation, real time estimates of methane-hydrogen composition, allowing the engine control system to adapt the control parameters engine. The algorithm is based on the innovative data-driven technology Direct Virtual Sensor, which allows to design the Virtual Sensor from the experimental data collected from a testing car, subject to suitable manoeuvres in different operational conditions, without requiring deep first principle modelling of the involved systems. The Virtual Sensor has been designed and implemented on the Electronic Control Unit of the demonstrator vehicle, giving suitably discretized estimates of Methane-Hydrogen composition, using measurements of engine revolution speed, of the lambda probe value and a variable from engine control unit. Experimental results of the Virtual Sensor performance evaluated in different operational conditions are presented.

Environmental Control System (ECS) of an aircraft is a complex system which operates classically in an air standard refrigeration cycle. ECS controls the temperature, pressure and flow of supply air to the cockpit, cabin or occupied compartments. The air cycle system of ECS takes engine bleed air as input. Parameters like bleed air pressure and temperature, mass flow, the external factors like ambient temperature, pressure, and aircraft attitude affect the performance of ECS to a large extent especially during transient. So, it is very important to consider the transient characteristics of these parameters in the design stage itself in order to ascertain the dynamic response of the system. This paper explains in detail the importance of transient input characteristics during the detailed design of ECS. A typical temperature control scheme for combat aircraft ECS has been studied and modeled in LMS AMESim. Cases of transient response of temperature control system are simulated and confirmed with actual scenario. The validated model and results can be used in designing a better control on ECS.

The Indian automotive industry has migrated from BS IV (Bharat stage IV) to BS VI (Bharat Stage VI) emission norms from 1st April 2020. This two-step migration of the emission regulations from BS IV to BS VI demands significant engineering efforts to design and integrate highly complex exhaust after-treatment system (EATS). In the present work, the methodology used to evaluate the EATS of a high power-density 1.5-liter diesel engine is discussed in detail. The EATS assembly of the engine consists of a diesel oxidation catalyst (DOC), a diesel particulate filter with selective catalytic reduction coating (sDPF), urea dosing module and urea mixer. Typically, all these components that are needed for emission control are integrated into a single canning of shell thickness ~1.5mm. Moreover, the complete EATS is directly mounted onto the engine with suitable mounting brackets on the cylinder block and cylinder head. The mounting brackets of the after-treatment system should be stiff enough to withstand the high cycle fatigue vibration loads coming from the engine. On the other hand, the brackets should allow the system to expand freely under high temperatures to avoid any low cycle fatigue issues created due to thermal loads at 800 deg.C. Hence, a robust methodology is followed to ensure the robustness of the entire system. The methodology included the prediction of metal temperature using a conjugate heat transfer analysis, high-temperature modal analysis, stress-strain analysis and high-cycle vibration fatigue analysis. In order to evaluate the system from the thermal compliance point of view, a high-temperature stress-strain analysis is carried out in a thermal shock test cycle. The simulation results have shown that the brackets positioned at the near-zero thermal expansion zone could have a much lesser plastic strain due to reduced thermal stress. Taking advantage of this, the stiffness of the brackets could be increased to improve the modal frequency values and robustness against high-cycle vibration fatigue. The paper gives a detailed insight on optimizing the bracket design of the EATS to ensure that a robust design solution is finalized.

This paper presents a proposed space vector pulse width modulation (SVPWM) controller for permanent magnet synchronous motor (PMSM). The Space vector pulse width modulation controller is used for power loss, torque ripple minimization of this type of motors. The proposed controller is a newly applied of Belt starter generator (BSG). The dynamic response of the BSG with the proposed controller is studied during the starter and generator modes with desired torque and speed with the optimal Id, Iq current input. The effectiveness of the proposed space vector pulse width modulation is then analyzed with Field oriented control (FOC) characteristics in the BSG operating system. The analysis results are presented to demonstrate the characteristics and effectiveness of the proposed control techniques.

Vehicles with manual transmission are still the most preferred choice in emerging markets like India due to their benefits in cost, simplicity and fuel economy. However, the ever-increasing vehicle population and traffic congestion demand a smooth clutch operation and a comfortable launch behaviour of any manual transmission vehicle. In the present work, the launch performance of a sports-utility vehicle (SUV) equipped with dual mass flywheel (DMF) and self-adjusting technology (SAT) clutch could be improved significantly by optimizing the clutch system.The vehicle was observed to be having a mild judder during clutch release (with 0% accelerator pedal input) in a normal 1st gear launch in flat road conditions. An extensive experimental measurement at the vehicle level could reveal the launch judder is mainly due to the 1st order excitation forces created by the geometrical inaccuracy of the internal parts of the clutch system. Moreover, the forces are amplified by the resonance of the complete driveline with the first eigen mode at 8 to 12 Hz. A detailed study in the 1-dimensional torsional simulation model revealed that the eigen mode frequency of the real-wheel drive architecture is mainly driven by several parameters (mass, inertia, torsional stiffness) of the driveline components. Hence, the 1st order excitation forces were needed to be controlled to improve the launch performance. Based on the detailed design of experiments (DOE), it was evident that the cushion disc stiffness and clutch disc parallelism are the significant contributors to the excitation forces. The launch performance of the vehicle could be significantly improved by reducing the cushion disc stiffness at lower axial load (300 N) and by controlling the clutch disc parallelism within a tight tolerance range. The effect of these modifications on different launch conditions is also explained in detail in the present work. The paper gives a holistic view of improving the launch performance of any vehicle without compromising any other parameter.

This paper presents a smart electric scooter system consisting of a microprocessor based vehicle controller (integrating an embedded regenerative braking controller), a 300W Permanent Magnet (PM) DC motor, two low-power DC-DC converters to form a higher power DC-DC converter pack, a motor controller, a supercapacitor bank and a capacitor cell balancing sub-system. During acceleration or forward motoring mode, the vehicle controller sets the DC motor into motoring mode to further utilizing motor controller regulate wheel speed and acceleration torque, whereas during deceleration or forward braking mode, sets the DC motor into braking mode and further utilizing regenerative braking controller regulate wheel speed and braking torque, as well as functions as a constant current (whose reference value is adjustable via a potentiometer) generator to charge the supercapacitor bank in a controllable fashion, hence not only successfully replacing frictional braking to certain degree, but also increasing the total energy efficiency dramatically owing to the low internal resistance and larger capacitance of the supercapacitor compared with other conventional regenerative braking systems via batteries. General structure of the smart system, control principle of the controllers, realization of measurement platform, experimental test setup as well as validation with results are all presented within this paper. Copyright © 2014 SAE International.

Due to the prevalent fuel economy, research on electric hybrid vehicles (HEVs) has attracted recently widespread attention. However, most researches were focused on electrification, neglecting the crucial role of internal combustion engines (ICEs) in reducing fuel consumption. Holding the opinion that ICEs can contribute more in developing fuel economic vehicles, we present in this paper a new HEV topology with two ICEs - Dualhybrid. Two separate traction units, conventional drivetrain with ICE1at front axle and electric hybrid drivetrain with ICE2+battery at rear axle constitute the powertrain of this new HEV concept. One dimensional simulation with sub-models built upon different modelling methods is implemented. Energy management of Dualhybrid is identified with a rule-based control strategy. Base and Fullhybrid model were built as references and a comparative simulation among the three models as conducted. On the basis of the simulation results, an analysis of the efficiency of the powertrains was performed in detail. Results show that Dualhybrid equipped with two ICEs is more fuel economic compared to the reference models and has proven to be an effective HEV concept.

The optimal control of hybrid powertrains represents one of the most challenging tasks for the compliance with the legislation concerning CO2 and pollutant emission of vehicles. Most common off-line optimization strategies (Pontryagin minimum principle-PMP-or dynamic programming) allow to identify the optimal control along a predefined driving mission at the expense of a quite relevant computational effort. On-line strategies, suitable for on-vehicle implementation, involve a certain performance degradation depending on their degree of simplification and computational effort. In this work, a simplified control strategy is presented, where the conventional power-split logics, typical of the above-mentioned strategies, is here replaced with an alternative utilization of the thermal and electric units for the vehicle driving (Efficient Thermal Electric Skipping Strategy-ETESS). The choice between the units is realized at each time and is based on the comparison between the effective fuel rate of the thermal engine and an equivalent fuel rate related to the electrical power consumption. The equivalent fuel rate in a pure electric driving is associated to a combination of brake specific fuel consumption of the thermal engine, and electro-mechanical efficiencies along the driveline. The ETESS is applied for the simulation of segment C hybrid vehicle, equipped with a thermal engine and two electric units (motor and generator). The methodology is tested along regulatory driving cycles (WLTP, Artemis) and RDE, with different powertrain variants. Numerical results underline that the proposed approach performs very close to most common control strategies (consumed fuel per kilometer higher than PMP of about 1% on average). The main advantage is a reduced computational effort (decrease of 99% on average). The ETESS is straightforwardly adapted for an on-line implementation, through the introduction of an adaptative factor, preserving the computational effort and the fuel economy.

Driving cycles are typically used for estimation of vehicle fuel/energy consumption and CO2 emissions. In most of applications only the vehicle velocity vs. time profile is considered as a driving cycle, while a road slope is typically omitted. Since the road slope significantly impacts the fuel consumption, it should be included into realistic driving cycles for hilly roads. As a part of wider research of multidimensional driving cycle synthesis, this paper focuses on analysis of a broad city bus driving cycle dataset recorded in the city of Dubrovnik. The analysis is aimed at revealing the impact of road slope on velocity and acceleration distributions, and clustering the recorded data into several groups reflecting various driving and traffic congestion characteristics. Finally, the Markov chain method is employed to synthesize 3D driving cycles for the selected data clusters, where the Markov chain states include vehicle velocity, vehicle acceleration, and road slope. The synthesized cycles are validated to ensure their representativeness in terms of faithful description of main features of the recorded driving cycles.

This paper shows the main results of a research activity carried out in order to investigate the impact of different hybridization concepts on vehicle fuel economy during standard homologation cycles (NEDC, FTP75, US Highway, Artemis). Comparative analysis between a standard passenger vehicle and three different hybrid solutions based on the same vehicle platform is presented. The following parallel hybrid powertrain solutions were investigated: Hybrid Electric Vehicle (HEV) solution (three different levels of hybridization are investigated with respect to different Electric Motor Generator size and battery storage/power capacity), High Speed Flywheel (HSF) system described as a fully integrated mechanical (kinetic) hybrid solution based on the quite innovative approach, and hydraulic hybrid system (HHV). In order to perform a fare analysis between different hybrid systems, analysis is also carried out for equal system storage capacities. All hybrid powertrain architectures include state-of-the-art hybrid components and are analyzed from the aspects of fuel economy related to the overall system efficiency, load point moving of the internal combustion engine due to energy flow control strategy operation, and regenerative braking (applying realistic drivability constraints). The simulations were performed within the IAV-VeLoDyn software environment. VeLoDyn (Vehicle Longitudinal Dynamics Simulation) is a modular and highly flexible Simulink-based software tool, which offers a straightforward simulation of longitudinal vehicle dynamics with special considerations on the driveline and model management functionality. In order to provide control and management of the hybrid powertrain system, a cycleindependent control strategy has been implemented into the supervisory hybrid control unit model, based on Equivalent Consumption Minimization Strategy (ECMS) approach. Due to the modular nature of the simulation tool, the control strategy was effectively implemented in all analyzed hybrid models with marginal modifications. In order to determine energy flows and validate hybrid powertrain behavior, a cycle-based energetic analysis was carried out, and the main results are presented in the paper.

A new design of integrated Electric Parking Brake system, called iEPB and integrated in the brake caliper, is introduced in this paper. It consists of an electrically operated brake unit and a hydraulically pressed unit independently, and uses a special self-locking mechanism instead of a screw device to increase the efficiency and the working speed. With all conventional EPB system’s advantages, it also provides a stronger brake performance and a faster reaction time. In this paper, we describe the working principle of this new design at first, and then introduce the arrangement of the testing system, followed by a discussion of experimental data. The testing results prove the feasibility of this design. The conclusion paragraph summarizes the key points about the design of the iEPB system. INTRODUCTION The iEPB system is more convenient and safety than traditional parking systems. It’s operated and released automatically. With integrated intelligent function, the iEPB system has the following merits: • Replace a hand lever by an operation button. • Because of no hand lever, there is more space in the vehicle. • Combining a control unit, the iEPB system can be automatically operated and released at the right time, which makes the operation simpler and the driver to feel more comfortable and safer. • With high performance mechanism, the iEPB system has a faster reaction time. So we can provide the Auto-Hold function by adopting the iEPB system. There are two types of existing electric parking brake. One type is the cable puller[3], and the other is the integrated caliper[4]. This new design belongs to the integrated caliper type. Almost 100% integrated caliper type of market products use the screw device as its linear mechanism. The screw device can provide a large reduction ratio in a small space and transfer the rotation motion into linear motion with a non-reverse feature. But a low mechanical efficiency due to the screw friction makes a great energy lose. In this paper, we introduce a new design that is a type of screw free concept. Basing on the same power source, the screw free design can reduce about three-quarter reaction time of the system [5]. SYSTEM DESCRIPTION For improving working speed, enhancing mechanism efficiency and providing a non-reverse feature at the same time, the iEPB mechanism design is the key point. The important factors that need to be considered include: • Caliper pressing force. • Working time of the actuator. • Power consumption. • Parking force that can be maintained when power off. Actuator parts The iEPB system working flow diagram is shown in Figure 1, and the illustration of actuator is shown in Figure 2. The iEPB system is comprised of a brush DC motor, a special self-locking mechanism and multi stage reduction gears. The output torque rotates a cam shaft built in the caliper and pushes brake lining to against brake disk for parking purpose, shown in Figure 3. There is no additional friction lose because of the screw free mechanism. The prototype picture is shown in figure 4. Motor Self-locking mechanism Reduction gear Caliper cam shaft Cam Lining shoe Parking Figure 1. iEPB system working flow diagram. Reduction Gear Self-locking mechanism

The ideal attributes of light weight, low cost and high power density have made the 2-stroke engine unrivalled in the scooter and moped market for many years. However, the challenges of meeting new emissions regulations, especially the latest Euro III emission test cycle have reduced the 2-stroke's dominance and it is now often considered to be too dirty and inefficient to have a future. As a result its product placement is on the decline. This paper introduces and discusses the latest application of a low-cost high-frequency injection system (Pulse Count Injection [1,2]) to both the fuel flow and lubrication oil flow of a 2-stroke scooter; allowing both fluids to be individually mapped and optimised for the complete engine operating range. This in turn enables the 2-stroke engine to pass the latest Euro III test whilst improving the fuel economy by a considerable margin, without changing the architecture of the engine. Examples of the latest developments of a highly integrated engine management system, including fuel and oil injector technology are shown. The paper draws conclusions from the test results showing the clear benefits of electronic fuel injection both for emissions and fuel consumption, and demonstrates that these benefits are achievable from a compact well integrated throttle body unit suitable for the small 2-stroke engine market. INTRODUCTION: 2-STROKE MOTOR APPLICATIONS, CONCERNS AND FUTURE POSSIBILITIES Although the 4-stroke engine has replaced 2-stroke engines in markets where emission legislation has been brought in force, there are still many applications where the light weight and low cost benefits of the 2-stroke engines are so significant as to make them irreplaceable. The lower powered, heavier and more costly 4-stroke engine replacement would severely compromise the function and/or performance of the end product. Examples Page 2 of 14 of these applications are the chainsaw, small outboard motor and limited capacity 'moped' or scooter, where maximum power from a very small, lightweight and low cost engine is paramount. Examples are shown in Figure 1. Figure 1 Examples of applications requiring the lightweight power of a 2-stroke engine However, even in these specialised areas there is a necessity to meet new clean emission standards and reduce fuel consumption (CO2 emissions) in line with environmental trends. It is therefore essential that full electronic control of the 2-stroke engine is applied in order to fully optimise the combustion and performance of these small engines and ensure compliance with future standards. Table 1 shows the historic emissions regulation limits for 2-stroke mopeds and the proposed new limits coming into force in 2012. Table 1 Emission limit trend for 50cc mopeds. Stages Emission limits for type approval and conformity of production for Mopeds Test cycle CO (g/km) HC + NOx (g/km) 1999 (EURO 1) 6.0 3.0 UN-ECE Reg.47 2002 (EURO 2) 1.0 1.2 UN-ECE Reg.47 2012 (EURO 3) 1.0 1.2 UN-ECE Reg.47 Hot and Cold Cycles Previous work has been done showing the dramatic reduction in emissions that can be achieved with 2-stroke engines using "Direct Injection" of the fuel into the combustion chamber [3,4,5] and this technology is often applied to high end expensive 2-stroke engines such as high performance outboard motors and jet skis. However, this solution while technically applicable to the smaller engines carries with it a high on-cost and complexity which has prevented it from large scale application in the low cost markets.

In the study presented in this paper, a vehicle driving cycle simulation of the pneumatic hybrid has been conducted. The pneumatic hybrid powertrain has been modeled in GT-Power and validated against experimental data. The GT-Power engine model has been linked with a MATLAB/simulink vehicle model. The engine in question is a single-cylinder Scania D12 diesel engine, which has been converted to work as a pneumatic hybrid. The base engine model, provided by Scania, is made in GT-power and it is based on the same engine configuration as the one used in real engine testing. During pneumatic hybrid operation the engine can be used as a 2-stroke compressor for generation of compressed air during vehicle deceleration and during vehicle acceleration the engine can be operated as a 2-stroke air-motor driven by the previously stored pressurized air. There is also a possibility to use the stored pressurized air in order to supercharge the engine when there is a need for high torque, like for instance at take off after a standstill or during a overtake maneuver. Previous experimental studies have shown that the pneumatic hybrid is a promising concept with great possibility for fuel consumption reduction during city-driving conditions. Earlier studies have shown a great reduction in fuel consumption whit the pneumatic hybrid compared to conventional vehicles of today. However, most of these studies have been completely of theoretical nature. In this paper, the engine model is based on and verified against experimental data, and therefore more realistic results can be expected. The intent with the vehicle driving cycle simulation is to investigate the potential of the pneumatic hybrid regarding reduction in fuel consumption (FC) compared to a traditional internal combustion engine (ICE) powered vehicle. The results show that a reduction in fuel economy of up to about 30% is possible for a pneumatic hybrid bus on the Braunschweig duty cycle. The main part of this reduction comes from the stop/start functionality of the system, while regenerative braking only contributes with 8.4 % to the reduction in FC. The results also show that an amazing 87% of the braking power can be absorbed and converted to compressed air. However, only a small portion of this energy, about 20%, can be converted to positive work. (Less)

The performance and design criteria for seat systems require that the seat be lighter for reduced fuel consumption while still meeting the safety requirements as required by legislation. The safety requirements for seats include headrests and seat back static and dynamic structural performance, seat belt anchorage and luggage retention capability, child seat anchorage and top tether requirements as defined by pertinent regulation. The interior space constraints require that the seat be thinner. The seat design is expected to address the growing concern for environmental friendliness. In addition to these main criteria, various additional features such as adjustable and stow-able design are required for customer delight. All these design objectives should be met within a given cost target. Conventional seating systems include a steel frame, with springs attached to provide support and flexibility to foam cushions. The steel frame is made up of several parts welded together. Weight of the seating system can be 80% of the weight of the interior of the vehicle. This paper deals with plastic front and rear seat designs that provide more than 20% weight reduction. The lighter seat improves the vehicle fuel efficiency, reducing CO2 emissions and the material of construction includes recyclable plastics and “green” polyurethane foam, making this design eco-friendly. Low cycle time of molding, reduced part count and assembly time, optimized contours for comfort and reduced material consumption lead to cost competitive design. The optimized structural properties and processability of various thermoplastics and thermoset polymer systems offer good stiffness and impact properties at fast cycle times. The combination of ease of processing, excellent mechanical behavior, dimensional stability and a wide operating temperature window make these materials a suitable choice for construction of seat systems. It is critical to combine the seat structure design with the appropriate choice of foam to provide comfort to the passenger, while minimizing weight and costs. Various implicit and explicit finite element analyses codes are used to simulate the process, structural and crash behavior in order to optimize the design, minimizing weight while meeting various regulatory requirements. This paper deals with the design, process, materials and the development methodology for plastic seats to meet various structural regulations and help fulfill the environmental demands on emissions and fuel consumption.

Internal combustion engine noise and vibration is a major issue for car makers, and this is even more important for High-Level Pick-ups and SUV’s which applies the modern diesel engines. One important player in this scenario is the second-order unbalanced forces vibration produced for the conventional inline 4 cylinder engine configurations, which leads to highfrequency excitation of vehicle’s structure and consequent internal noise. This paper studies the balancer shaft solution for the mentioned engine configuration, as well as major design alternatives and development process and issues. This paper also presents an example of balancer shaft design and development for a high speed diesel engine, as well as proposes a design-decision matrix methodology applied. Such methodology, which can be applied to any design or engineering case, is a way to design engineers to make the right decision amongst the different options that are always offered by a very simple and objective matrix.

Flex Track Drilling systems are being used increasingly in aerospace applications providing low cost, highly efficient automated drilling systems. Certain applications like circumferential splice drilling on large size airplane fuselages require multi spindle flex track systems working in tandem to meet production efficiency requirements. This paper discusses the development of a multi spindle flex track drilling system for a circumferential splice drilling on the 777 airplane. The multi spindle system developed uses a variety of flex track carriages attached to the flexible vacuum tracks to allow for offset or wide inside drilling. Segmented machine programmes allow these multiple machines to be deployed on the same circumferential splice on the airplane providing the multi spindle system. Interfacing of the multiple spindles is achieved by a custom OEM interface using a single screen thereby ensuring simplicity of operation. A central database location ensures that all programmes are current and maintains operational status of all holes being drilled. Tool life monitoring is also provided to ensure consistent tool changeovers for maintaining hole quality and process capability. Flexible track lengths can be spliced together for long lengths and shortened for clearance or areas using smaller programmes. This paper also discusses the development of the carriage hardware specific to the 777 airplane requirements using the methodology of adapting existing flex track system designs as well as point design specific to the 777 Fuselage Circumferential Splice Drilling Application. INTRODUCTION In the fall of 2007, a Boeing internal cross-functional team was chartered to investigate implementation of automation technologies to mitigate the challenges that have increased with higher production rates in 777 fuselage assembly. A technical report published by this team proposed the application of selective automation to the 777 Fuselage Integration processes. By implementing selective automation the benefits of reduced repetitive injuries, reduction of skin quality defects and lower cycle time in some of the fuselage integration processes would be realized. An additional benefit would also be the resultant consistent/repeatable and reliable process. These improvements would drive a better work environment, which would reflect on better attendance, less attrition and a higher employee morale. This Technology implementation would result in an improved product to the customer. After a detailed investigation of current build processes of longitudinal and circumferential splices it was determined that the focus should be on automation of the drilling of the circumferential splice on the 777-300 airplane, Aft fuselage section. To reduce developmental cost it was determined to use as much as possible offthe-shelf technologies with minimal developments needed to adapt to the 777 airplane requirements. Also taken into consideration was that the equipment chosen would need to be adaptable with few or no changes to current Floor Assembly Jig (FAJ) or floor mounted equipment (FME). SELECTIVE AUTOMATION PROPOSAL A technical evaluation of the longitudinal and circumferential splice drilling and fastening processes revealed that application of automation to selected portions of these processes would provide the greatest benefit for the investment incurred. On circumferential splice drilling and fastening processes it was discovered that the drilling processes constituted almost 70% of the total process time. These drilling processes included pilot drilling of holes, full size drilling of holes as well as countersinking processes. Any implementation of automation on these drilling processes would yield major gains in productivity including additional benefits of improved ergonomics, improved skin quality and overall an improvement of the production process and overall product quality. The study of the automation of the fastening processes for the circumferential splices yielded that gains realized by automation would not result in great improvements in productivity for these processes. Some of the gains would be offset by the additional process monitoring time as required by engineering specifications for the automated fastening processes. By focusing on the drilling processes only of the circumferential splices, the automation equipment requirements were also greatly simplified due to the omission of additional fastener insertion end effectors, clamp up equipment etc. This allowed the team to evaluate more options for the automated drilling equipment as many suppliers met the specifications for the drilling equipment but not for the drilling/fastening equipment, making it easier to obtain off the shelf automated drilling equipment. A time study along with an ergonomic study, combined with production process data including quality charts was compiled to help arrive at a decision for development and implementation of selective automation in 777 Fuselage Integration.

With a transition towards electric vehicles for the transport sector, there will be greater reliance put upon battery packs; therefore, battery pack modelling becomes crucial during the design of the vehicle. Accurate battery pack modelling allows for: the simulation of the pack and vehicle, more informed decisions made during the design process, reduced testing costs, and implementation of superior control systems. To create the battery cell model using MATLAB/Simulink, an electrical equivalent circuit model was selected due to its balance between accuracy and complexity. The model can predict the state of charge and terminal voltage from a current input. A battery string model was then developed that considered the cell-to cell variability due to manufacturing defects. Finally, a full battery pack model was created, capable of modelling the different currents that each string experiences due to the varied internal resistance. The model was then validated with real-life data from the “Hill Route” section of the First Group Millbrook Fuel Economy Test Version 5.0 drive cycle of a mild hybrid electric bus. Results showed a strong correlation with the measured data and both the state of charge and terminal voltage simulations of the model. For the string model, results showed that there was a slight variance in the state of charge between cells in a string with varied capacities. However, terminal voltages between cells did not vary significantly with variances in internal resistance. Future work includes the creation of a thermal sub-model and an ageing sub-model, which considers whether the location of a cell within a pack has a correlation with its degradation. These sub-models will then be integrated and used as a full battery pack model.

As part of the U.S. Environmental Protection Agency’s (EPA’s) continuing assessment of advanced light-duty automotive technologies in support of regulatory and compliance programs, a 2018 Toyota Camry A25A-FKS 4-cylinder, 2.5-liter, naturally aspirated, Atkinson Cycle engine with cooled exhaust gas recirculation (cEGR) was benchmarked. The engine was tested on an engine dynamometer with and without its 8-speed automatic transmission, and with the engine wiring harness tethered to a complete vehicle parked outside of the test cell. Engine and transmission torque, fuel flow, key engine temperatures and pressures, onboard diagnostics (OBD) data, and Controller Area Network (CAN) bus data were recorded. This paper documents the test results under idle, low, medium, and high load engine operation. Motoring torque, wide open throttle (WOT) torque and fuel consumption are measured during transient operation using both EPA Tier 2 and Tier 3 test fuels. The design and performance of this 2018 2.5-liter engine is described and compared to Toyota’s published data and to EPA’s previous projections of the efficiency of an Atkinson Cycle engine with cEGR. The Brake Thermal Efficiency (BTE) map for the Toyota A25A-FKS engine shows a peak efficiency near 40 percent, which is the highest value of any publicly available map for a non-hybrid production gasoline internal combustion (IC) engine designed to run on 91 RON fuel. Further improvement is possible by application of fixed discrete or full continuous cylinder deactivation, both of which are currently in production on other engines.

Engine downsizing is a promising trend to decarbonise vehicles but it also poses a challenge on vehicle driveability. Electric turbochargers can solve the dilemma between engine downsizing and vehicle driveability. Using the electric turbocharger, the transient response at low engine speeds can be recovered by air boosting assistance. Meanwhile, the introduction of electric machine makes the engine control more complicated. One emerging issue is to harness the augmented engine air system in a systematical way. Therefore, the boosting requirement can be achieved fast without violating exhaust emission standards. Another raised issue is to design an real time energy management strategy. This is of critical to minimise the required battery capacity. Moreover, using the on-board battery in a high efficient way is essential to avoid over-frequent switching of the electric machine. This requests the electric machine to work as a generator to recharge the battery. The capability of generating power strongly depends on the engine operating point. One big challenge is that the calibration of generating power capability is time-consuming in experiments. This paper proposes a neuro-fuzzy approach to model the engine. Based on the virtual engine model, the capability of generating power at arbitrary engine operating point can be obtained fast and accurately, which is applicable to implement in real time.

Aerospace electrical systems are continuing to increase their voltage levels to meet the on-board power demands of more-electric aircraft (MEA) wherehydraulic and pneumatic systems are replaced with electrical equivalents. This trend will only continue as hybrid and allelectric aircraft are developed. These higher power demands require the use of higher voltages and as such it is essential to explore the behaviour of the insulation system in the aerospaceenvironment. This insulation must operate in an environment where the operating temperatures range from 250°C to -65°C, the air pressure is around one tenth of that at ground level and where the levels of humidity and ozone vary rapidly. Understanding the impact of these variables on aircraft highvoltage insulation systems is crucial in predicting their behaviour and lifetime. Our work with the IAGOS atmospheric dataset presents worst-case and typical flight environments for higher than expected cruising altitudes, and uses thefindings to compare the relative rates of degradation of insulating materials at ground and cruising altitudes.

© 2018 SAE International. All Rights Reserved. The current procedure for testing emissions from new vehicles, the World Harmonised Light Vehicle Test Procedure (WLTP), was introduced in September 2017. The WLTP was developed by collecting over 765,000 kilometres worth of data in order to isolate driver behaviour from other real world variables. However, this is a very time consuming and costly process. This paper discusses the suitability of a cheaper and more time efficient alternative. Driver behaviour has a significant impact on the emissions produced from the same vehicle. This study explores the feasibility of utilising virtual environments as an alternative to real world testing to isolate driver behaviour to develop future drive cycles. The use of virtual environments have some significant advantages over real world testing: they can be strictly controlled in terms of the weather, topography and vehicle characteristics, thereby aiding the isolation of driver behaviour from other variables. A driving simulator facility based at the University of West of England was used to assess the suitability of determining driver behaviour using a virtual environment. A track was created based on a local route in the virtual environment. The virtual route was driven by volunteers and their driving behaviours were identified. The same route in the real world was driven by the same volunteers. The driving behaviour of the volunteers from both the virtual environment and the real world are compared to assess the realism of the virtual driving experience in terms of driver behaviour. Finally the data from the virtual environment were analysed to determine if driver behaviour can be isolated, along with the impact on vehicle emissions, with a view to using virtual environments to develop future drive test cycles for emissions testing.

The geometrical design of the airbox for an internal combustion engine has a significant effect on the pressure loss in the entire inlet tract. Due to the location of the airbox, its size and shape is usually limited as a result of the proximity to other underbonnet features.The shape is also limited by manufacturing, assembly and NVH considerations. The complexity of the unsteady flow through the airbox and the constraints placed upon it by the available volume in the under-bonnet area make this a challenging design task. This paper reviews the current thinking on methods used to optimize Computational Fluids Dynamics (CFD) problems and how this would apply to the optimization of an airbox for an internal combustion engine. The paper then goes on to detail the findings of the initial validation work on the CFD method for predicting the pressure loss through an airbox. An optimization case study is then presented based on one of the models used for the validation.

To overcome future stringent regulations on pollutant emissions and to decrease CO emissions and fuel consumption, hybrid vehicles seem to be one of the near future most promising technologies. This type of car uses complex energy management and control strategy. Simulation can be very useful for the development of such a control system. This paper highlights a new library developed under the AMESim software that enables the simulation of complex interactive systems in vehicles. In addition, the possibility to combine with other AMESim modules, allows the users to add more complexity to any of the sub-components of the vehicle. As an illustration of this new tool capability, we propose in this paper a simulation example of the Prius, the most known hybrid vehicle which was the first commercial vehicle in 1997 and selected as the 2004 Car of the Year in Europe. Comparisons between measurements and simulations of the response of different components are presented on different driving cycles.

This paper presents Direct Gear Design – an alternative method of analysis and design of involute gears which separates gear geometry definition from tool selection to achieve the best possible performance for a particular product and application. This method has successfully been applied for a number of automotive applications. Some examples will be presented at the end of the paper.

This paper describes a new 5.6-liter DOHC V8 engine, VK56DE, which was developed for use on a new fullsize sport utility vehicle and a full-size pickup truck. To meet the demands for acceleration performance when merging into freeway traffic, passing or re-acceleration performance from low speed in city driving and hillclimbing or passing performance when towing, the VK56DE engine produces high output power at top speed and also generates ample torque at low and middle engine speeds (90% of its maximum torque is available at speeds as low as 2500 rpm). Furthermore, this engine achieves top-level driving comfort in its class as a result of being derived from the VK45DE engine that was developed for use on a sporty luxury sedan. Development efforts were focused on how to balance the required performance with the need for quietness and smoothness. This paper presents a detailed description of the VK56DE engine as well as highlights of individual technologies contributing to its highly balanced performance.