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Due to the integration of many interacting subsystems like hybrid vehicle management, energy management, distance management, etc. into the VCU platform the design steps for function development and calibration become more and more complex. This makes an aid necessary to relieve the development. Therefore, the aim of the proposed simulation-based development and calibration design is to improve the time-and-cost consuming development stages of modern VCU platforms. A simulation-based development framework is shown on a complex function development and calibration case study using an advanced powertrain concept with a plug-in hybrid electric vehicle (PHEV) concept with two electrical axles. Presenter Thomas Boehme, IAV GmbH

Due to the integration of many interacting subsystems like hybrid vehicle management, energy management, distance management, etc. into the VCU platform the design steps for function development and calibration become more and more complex. This makes an aid necessary to relieve the development. Therefore, the aim of the proposed simulation-based development and calibration design is to improve the time-and-cost consuming development stages of modern VCU platforms. A simulation-based development framework is shown on a complex function development and calibration case study using an advanced powertrain concept with a plug-in hybrid electric vehicle (PHEV) concept with two electrical axles.

The recent advance in the development of various hybrid vehicle technologies comes along with the need of establishing optimal energy management strategies, in order to minimize both fuel economy and pollutant emissions, while taking into account an increasing number of state and control variables, depending on the adopted hybrid architecture. One of the objectives of this research was to establish benchmarking performance, in terms of fuel economy, for real time on-board management strategies, such as ECMS (Equivalent Consumption Minimization Strategy), whose structure has been implemented in a SIMULINK model for different hybrid vehicle concepts.

To meet the requirements in relation to pollutants, CO2-emissions, performances, comfort and costs for 2025 timeframe, many technology options for the powertrain, that plays a key role in the vehicle, are possible. Beside the central aspect of reducing standard cycle consumption levels and emissions, consumer demands are also growing with respect to comfort and functionality. In addition, there is also the challenge of finding cost efficient ways of integrating technologies into a broad range of vehicles with different levels of hybridization. High degrees of electrification simultaneously provide opportunities to reduce the technology content of the internal combustion engines (ICE), resulting in a cost balancing compromise between combustion engine and hybrid technology. The design and optimization of powertrain topologies, functionalities, and components require a complex development process.

The quantitative assessment and comparison of different hybrid vehicle options has traditionally been done on the basis of measuring or estimating the vehicle's fuel economy over predefined drive-cycles. In general, little or no consideration has been given to the more subjective and difficult to quantify vehicle requirements, such as trying to understand which derivative will be the most “fun” vehicle to drive. A lack of understanding in this area of vehicle performance sufficiently early within the development life-cycle so as to be in a position to influence the vehicle design, can lead to a compromised powertrain architecture which will ultimately increase the risk of product failure. The work presented within this paper constitutes part of the overall design activities associated with the LIFECar programme. The aim of the LIFECar consortium is to manufacture a lightweight, fuel cell hybrid electric sports vehicle.

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.

This paper proposes a current limits distribution control strategy for a parallel hybrid electric vehicle (parallel HEV) which includes an advanced powertrain concept with two electrical driving axles. One of the difficulties of an HEV powertrain with two electrical driving axles is the ability to distribute the electrical current of one high voltage battery appropriately to the two independent electrical motors. Depending on the vehicle driving condition (i.e., car maneuver) or the maximization of the entire efficiency chain of the system, a suitable control strategy is necessary. We propose an input-output feedback linearization strategy to cope with the nonlinear system subject to input constraints. This approach needs an external, state dependent saturation element, which translates the state dependent control input saturation to the new feedback linearizing input and therefore preserves the properties of the differential geometric framework.

This paper proposes a current limits distribution control strategy for a parallel hybrid electric vehicle (parallel HEV) which includes an advanced powertrain concept with two electrical driving axles. One of the difficulties of an HEV powertrain with two electrical driving axles is the ability to distribute the electrical current of one high voltage battery appropriately to the two independent electrical motors. Depending on the vehicle driving condition (i.e., car maneuver) or the maximization of the entire efficiency chain of the system, a suitable control strategy is necessary. We propose an input-output feedback linearization strategy to cope with the nonlinear system subject to input constraints. This approach needs an external, state dependent saturation element, which translates the state dependent control input saturation to the new feedback linearizing input and therefore preserves the properties of the differential geometric framework.

A kinetic energy recover system (KERS) captures the kinetic energy that results when brakes are applied to a moving vehicle. The recovered energy can be stored in a flywheel or battery and used later, to help boost acceleration. KERS helps transfer what was formerly wasted energy into useful energy. In 2009, the Federation Internationale de l’Automobile (FIA) began allowing KERS to be used in Formula One (F1) competition. Still considered experimental, this technology is undergoing development in the racing world but has yet to become mainstream for production vehicles. The Introduction of this book details the theory behind the KERS concept. It describes how kinetic energy can be recovered, and the mechanical and electric systems for storing it. Flybrid systems are highlighted since they are the most popular KERS developed thus far. The KERS of two racing vehicles are profiled: the Dyson Lola LMP1 and Audi R18 e-tron Quattro.

The application of hybridization technology is now widely regarded as a significant step forward to reduce fuel consumption and hence CO₂ emissions for ground vehicles. Many programs and much research has been done on these technologies in the automotive market, however little work has been done in the very cost sensitive market sector of the small motorcycle. This paper introduces and discusses the application of a low-cost hybrid technology to small motorcycles and scooters, and reviews some of the initial trade-offs through the use of a new hybrid simulation model developed at Cranfield University. The study being presented assessed the existing Energy Storage Systems (ESS) in the market. This list was reduced, omitting options which posed a clear safety or cost risk, or solutions which would disproportionally increased the Gross Vehicle Weight (GVW). Also omitted were storage options which could not be production ready in the near term, 3 - 5 years.

Currently known hybrid systems are technically complex, cost-intensive and referring to this for many end-customers not available. Under this boundaries IAV has developed a cost-optimal concept of an efficient and modular powertrain platform for electric and hybrid vehicles. The system is based on one unity gear-set for up to three speeds, which enables seamless shifting with only one friction based clutch. With this platform powertrains can be realized by using a maximum number of carry over parts (COP) for electric vehicles as well as for hybrids. The derivable hybrid powertrains of the platform system are designed for 48V electric motors (EM) which enables the maximum cost potential in combination with the realized gear set and transmission technology. The real simple powertrain platform concept is furthermore scalable for different vehicle segments optionally with or without a hybrid option.

After the realization of very low exhaust gas emissions and corresponding OBD requirements to fulfill Euro VI and Tier 4 legislation, the focus in heavy-duty powertrain development is on the reduction of fuel consumption and thus CO₂ emissions again. Besides this, the total vehicle operation costs play another major role. A holistic view of the overall powertrain system including the combustion process, exhaust gas aftertreatment, energy recuperation and energy storage is necessary in order to obtain the best possible system for a given application. A management system coordinating the energy flow between the different subsystems while guaranteeing low exhaust emissions plays a major part in operating such complex architectures under optimal conditions.

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.

Today, the contribution of the transportation sector on greenhouse gases is evident. The fast consumption of fossil fuels and its impact on the environment have given a strong impetus to the development of vehicles with better fuel economy. Hybrid electric vehicles fit into this context with different targets, starting from the reduction of emissions and fuel consumption, but also for performance and comfort enhancement. Lamborghini has recently invested in the development of a hybrid super sport car, due to performance and comfort reasons. Aventador series gearbox is an Independent Shift Rod gearbox with a single clutch and during gear shifts, as all the single clutch gearbox do, it generates a torque gap. To avoid the additional weight of a Dual Clutch Transmission, a 48V Electric Motor has been connected to the wheels, in a P3 configuration, to fill the torque gap, and to habilitate regenerative braking and electric boost functions.

With the increased interest in hybrid vehicle technology there is a need to investigate vast amounts of different hybrid vehicle topologies. Modelling and simulation plays an important role in this investigation process. In particular, modelling for controller development can quickly lead to model management and maintenance issues due to the variety of models required. The use of object oriented modelling languages can aid in plant model management by providing flexibility to different levels of users as well as reducing the number of separate plant models required for controller development. Two case studies are presented that illustrate some of the benefits gained from the object oriented modelling approach.

This paper investigates an optimal design of a diesel engine and after-treatment systems for a series hybrid electric forklift application. A holistic modeling approach is developed in GT-Suite® to establish a model-based hardware definition for a diesel engine and an after-treatment system to accurately predict engine performance and emissions. The used engine model is validated with the experimental data. The engine design parameters including compression ratio, boost level, air-fuel ratio (AFR), injection timing, and injection pressure are optimized at a single operating point for the series hybrid electric vehicle, together with the performance of the after-treatment components. The engine and after-treatment models are then coupled with a series hybrid electric powertrain to evaluate the performance of the forklift in the standard VDI 2198 drive cycle.

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.

The paper considers a novel waste heat recovery (WHR) system integrated with the engine architecture in a hybrid electric vehicle (HEV) platform. The novel WHR system uses water as the working media and recovers both the internal combustion engine coolant and exhaust energy in a single loop. Results of preliminary simulations show a 6% better fuel economy over the cold start UDDS cycle only considering the better fuel usage with the WHR after the quicker warm-up but neglecting the reduced friction losses for the warmer temperatures over the full cycle.

Hybrid electric vehicles (HEV) are considered as the most cost effective solution, in the short term perspective, for the achievement of improved fuel economy (FE) and reduced emissions. This paper focuses on regenerative braking in a mild hybrid powertrain with infinitely variable transmission (IVT) and specifically on how its control strategy can be formulated and optimized. The study is conducted using a previously validated fully dynamic powertrain model. An initial investigation of the dynamic vehicle behaviour under braking conditions serves as the basis for the development of a control strategy for best braking performance and maximum energy recovery, the implementation of which requires a fully active and integrated brake control system. Limitations and constraints due to driveline configuration and driveability issues are considered and their effect evaluated. Simulation results show that fuel consumption reductions of 12% are achievable along a standard drive cycle.

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.