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Noise, vibration and harshness (NVH) is one of the most important performance evaluation aspect of electric motors. Among the different causes of the NVH issues of electrical drives, the high-frequency spatial and temporal harmonics of the electrical drive system is of great importance. To reduce the tonal noise of the electric motors, harmonic injection methods can be applied. However, a lot of the existing related work focuses more on improving the optimization process of the parameter settings of the injected current/flux/voltage, which are usually limited to some specific working conditions. The applicability and effectivity of the algorithm to the whole frequency/speed range are not investigated. In this paper, a multi-domain pipeline of harmonic injection controller design for a permanent magnet synchronous motor (PMSM) is proposed.

Vehicle OEM’s for MHD applications are facing significant challenges in meeting the stringent 2027 low-NOx and GHG emissions regulations. To meet such challenges, advanced engine and aftertreatment technologies along with powertrain electrification are being applied to achieve robust solutions. FEV has previously conducted model-based assessments to show the potential of 48V engine and aftertreatment technologies to simultaneously meet GHG and low NOx emission standards. This study focuses on evaluating the full potential of 48V electrification technology through addition of 48V P3 hybrid system to the previously developed 48V advanced engine and aftertreatment technology package. Previously, a model-based approach was utilized for selection and sizing of a 48V system-enabled engine and aftertreatment package for class 6-7 MHD application.

Fuel economy improvement of Class 8 long-haul trucks has been a constant topic of discussion in the commercial vehicle industry due to the significant potential it offers in reducing GHG emissions and operational costs. Among the different vehicle categories in on-road transportation, Class 8 long-haul trucks are a significant contributor to overall GHG emissions. Furthermore, with the upcoming 2027 GHG emission and low-NOx regulations, advanced powertrain technologies will be needed to meet these stringent standards. Connectivity-based powertrain optimization is one such technology that many fleets are adopting to achieve significant fuel savings at a relatively lower technology cost. With advancements in vehicle connectivity technologies for onboard computing and sensing, the full potential of connected vehicles in reducing fuel consumption can be realized through V2X (Vehicle-to-Everything) communication.

Stochastic Preignition (SPI) is an abnormal combustion event that occurs in a turbocharged engine and can lead to the loss in fuel economy and engine hardware damage, and in turn result in customer dissatisfaction. It is a significant limiting factor on the use and continued downsizing of turbocharged spark ignited direct injection (SIDI) gasoline engines. Understanding and mitigating all the factors that cause and influence the rate and severity of SPI occurrence are of critical importance to the engine’s continued use and fuel economy improvements for future designs. Previous studies have shown that the heavy molecular weight components of the fuel formulations are one factor that influences the rate of SPI from a turbocharged SIDI gasoline engine. All the previous studies have involved analyzing the fuel’s petroleum hydrocarbon chemistry, but not specifically the additives that are put in the fuel to protect and clean the internal components over the life of the engine.

Electrification of heavy-duty trucks has received significant attention in the past year as a result of future regulations in some states. For example, California will require a certain percentage of tractor trailers, delivery trucks and vans sold to be zero emission by 2035. However, the relatively low energy density of batteries in comparison to diesel fuel, as well as the operating profiles of heavy-duty trucks, make the application of electrified powertrain in these applications more challenging. Heavy-duty vehicles can be broadly classified into two main categories; long-haul tractors and vocational vehicles. Long-haul tractors offer limited benefit from electrification due to the majority of operation occurring at constant cruise speeds, long range requirements and the high efficiency provided by the diesel engine.

Electrification of heavy-duty trucks has received significant attention in the past year as a result of future regulations in some states. For example, California will require a certain percentage of tractor trailers, delivery trucks and vans sold to be zero emission by 2035. However, the relatively low energy density of batteries in comparison to diesel fuel, as well as the operating profiles of heavy-duty trucks, make the application of electrified powertrain in these applications more challenging. Heavy-duty vehicles can be broadly classified into two main categories; long-haul tractors and vocational vehicles. Long-haul tractors offer limited benefit from electrification due to the majority of operation occurring at constant cruise speeds, long range requirements and the high efficiency provided by the diesel engine.

While significant progress has been made in recent years to develop hybrid and battery electric vehicles for passenger car and light-duty applications to meet future fuel economy targets, the application of hybrid powertrains to heavy-duty truck applications has been very limited. The relatively lower energy and power density of batteries in comparison to diesel fuel and the operating profiles of most heavy-duty trucks, combine to make the application of hybrid powertrain for these applications more challenging. The high torque and power requirements of heavy-duty trucks over a long operating range, the majority of which is at constant cruise point, along with a high payback period, complexity, cost, weight and range anxiety, make the hybrid and battery electric solution less attractive than a conventional powertrain.

The automotive industry continues to develop new powertrain and vehicle technologies aimed at reducing overall vehicle-level fuel consumption. Specifically, the use of electrified propulsion systems is expected to play an increasingly important role in helping OEM’s meet fleet CO2 reduction targets for 2025 and beyond. This will also include a strong growth in the global demand for electric drive units (EDUs). The change from conventional vehicles to vehicles propelled by EDUs leads to a reduction in overall vehicle exterior and interior noise levels, especially during low-speed vehicle operation. Despite the overall noise levels being low, the NVH behavior of such vehicles can be objectionable due to the presence of tonal noise coming from electric machines and geartrain components as well as relatively high shares of road/wind noise. In order to ensure customer acceptance of electrically propelled vehicles, it is imperative that these NVH challenges are understood and solved.

This article discusses highly flexible and accurate physics-based mean value modeling (MVM) for internal combustion engines and its wide applicability towards virtual vehicle calibration. The requirement to fulfill the challenging Real Driving Emissions (RDE) standards has significantly increased the demand for precise engine models, especially models regarding pollutant emissions and fuel economy. This has led to a large increase in effort required for precise engine modeling and robust model calibration. Two best-practice engine modeling approaches will be introduced here to satisfy these requirements. These are the exclusive MVM approach, and a combination of MVM and a Design of Experiments (DOE) model for heterogeneous multi-domain engine systems.

Demanding CO2 and fuel economy regulations are continuing to pressure the automotive industry into considering innovative powertrain and vehicle-level solutions. Powertrain engineers continue to minimize engine internal friction and transmission parasitic losses with the aim of reducing overall vehicle fuel consumption. In Part 1 of the study (2017-01-0893) described aspects of the test stand design that provides flexibility for adaptation to various test scenarios. The results from measurements for a number of front-end accessory drive (FEAD) components were shown in the context of scatterbands derived from multiple component tests. Key results from direct drive and belt-driven component tests were compared to illustrate the influence of the belt layout on mechanical efficiency of the FEAD system. The second part of the series will focus exclusively on the operation of the alternator. Two main elements of the study are discussed.

In-use compliance under LEV III emission standards, GHG, and fuel economy targets beyond 2025 poses a great opportunity for all ICE-based propulsion systems, especially for light-duty diesel powertrain and aftertreatment enhancement. Though diesel powertrains feature excellent fuel-efficiency, robust and complete emissions controls covering any possible operational profiles and duty cycles has always been a challenge. Significant dependency on aftertreatment calibration and configuration has become a norm. With the onset of hybridization and downsizing, small steps of improvement in system stability have shown a promising avenue for enhancing fuel economy while continuously improving emissions robustness. In this paper, a study of current key technologies and associated emissions robustness will be discussed followed by engine and aftertreatment performance target derivations for LEV III compliant powertrains.

The automotive industry continues to develop new technologies aimed at reducing overall vehicle level fuel consumption. Powertrain and driveline related technologies will play a key role in helping OEM’s meet fleet CO2 reduction targets for 2025 and beyond. Specifically, use of technologies such as downsized engines, idle start-stop systems, aggressive torque converter lock-up schedules, wide-ratio spread transmissions, and electrified propulsion systems are vital towards meeting aggressive fuel economy targets. Judicious combinations of such powertrain and driveline technology packages in conjunction with measures such as the use of low rolling resistance tires and vehicle lightweighting will be required to meet future OEM fleet CO2 targets. Many of the technologies needed for meeting the fuel economy and CO2 targets come with unique NVH challenges. In order to ensure customer acceptance of new vehicles, it is imperative that these NVH challenges be understood and solved.

In view of changing climatic conditions all over the world, Green House Gas (GHG) saving related initiatives such as reducing the CO2 emissions from the mobility and transportation sectors have gained in importance. Therefore, with respect to the large U.S. market, the corresponding legal authorities have defined aggressive and challenging targets for the upcoming time frame. Due to several aspects and conditions, like hesitantly acting clients regarding electrically powered vehicles or low prices for fossil fuels, convincing and attractive products have to be developed to merge legal requirements with market constraints. This is especially valid for the market segment of Light-Duty vehicles, like SUV’S and Pick-Up trucks, which are in high demand.

Modern combustion engines must meet increasingly higher requirements concerning emission standards, fuel economy, performance characteristics and comfort. Especially fuel consumption and the related CO2 emissions were moved into public focus within the last years. One possibility to meet those requirements is downsizing. Engine downsizing is intended to achieve a reduction of fuel consumption through measures that allow reducing displacement while simultaneously keeping or increasing power and torque output. However, to reach that goal, downsized engines need high brake mean effective pressure levels which are well in excess of 20bar. When targeting these high output levels at low engine speeds, undesired combustion events with high cylinder peak pressures can occur that can severely damage the engine. These phenomena, typically called low speed pre-ignition (LSPI), set currently an undesired limit to downsizing.

The demand for lower CO2 emissions requires not just the optimization of every single component but the complete system. For a transmission system, it is important to optimize the transmission hardware as we well as the interaction of powertrain components. For automatic transmission with wide ratio spreads, the main losses are caused by the actuation system, which can be reduced with use of ondemand actuation systems. In this paper, a new on-demand electromechanical actuation system with validation results on a clutch test bench is presented. The electro-mechanical actuator shows an increase in the efficiency of 4.1 % compared to the conventional hydraulic actuation in a simulated NEDC (New European Driving Cycle) cycle. This increase is based on the powerless end positions of the actuator (engaged and disengaged clutch). The thermal tension and wear are compensated with a disk spring. This allows a stable control over service life.

Lignocellulosic biomass consists of (hemi-) cellulose and lignin. Accordingly, an integrated biorefinery will seek to valorize both streams into higher value fuels and chemicals. To this end, this study evaluated the overall combustion performance of both cellulose- and lignin derivatives, namely the high cetane number (CN) di-n-butyl ether (DnBE) and low CN anisole, respectively. Said compounds were blended both separately and together with EN590 diesel. Experiments were conducted in a single cylinder compression ignition engine, which has been optimized for improved combustion characteristics with respect to low emission levels and at the same time high fuel efficiency. The selected operating conditions have been adopted from previous “Tailor-Made Fuels from Biomass (TMFB)” work.

Automatic engine start/stop systems are becoming more prevalent and increasing market share of these systems is predicted due to demands on improving fuel efficiency of vehicles. Integration of an engine start/stop system into a “conventional” drivetrain with internal combustion engine and 12V board system is a relatively cost effective measure to reduce fuel consumption. Comfort and NVH aspects will continue to play an important role for customer acceptance of these systems. Possible delay during vehicle launch due to the engine re-start is not only a safety relevant issue but a hesitating launch feel characteristic will result in reduced customer acceptance of these systems. The engine stop and re-start behavior should be imperceptible to the driver from both a tactile and acoustic standpoint. The lack of masking effects of the engine during the engine stop phases can cause other “unwanted” noise to become noticeable or more prominent.

The definition of vehicle and powertrain level targets is one of the first tasks toward establishing where a vehicle will reside with respect to the current or future state of industry. Though development of sound quality metrics is ongoing to better correlate objective data with subjective assessments, target setting at the vehicle level is relatively straightforward. However, realization of these targets depends on effective cascading to system and component levels. Often, component level targets are derived based on experience from earlier development programs, or based on selected characteristics observed during component level benchmarking. An approach is presented here to complement current strategies for component level target definition. This approach involves a systematic concept for definition of component NVH targets based on desired vehicle level performance and a consequent target break down.

The increased demand in fuel economy and the reduction of CO₂ emissions results in continued efforts to downsize engines. The downsizing efforts result in engines with lower displacement as well as lower number of cylinders. In addition to cylinder and displacement downsizing the development community embarks on continued efforts toward down-speeding. The combination of the aforementioned factors results in engines which can have high levels of torsional vibrations. Such behavior can have detrimental effects on the drivetrain particularly during the development phase of these. Driveshafts, couplings, and dynamometers are exposed to these torsional forces and depending on their frequency costly damages in these components can occur. To account for these effects, FEV employs a multi-body-system modeling approach through which base engine information is used to determine optimized drivetrain setups. All mechanical elements in the setup are analyzed based on their torsional behavior.

The interest in electric propulsion of vehicles has increased in recent years and is being discussed extensively by experts as well as the public. Up to now the driving range and the utilization of pure electric vehicles are still limited in comparison to conventional vehicles due to the limited capacity and the long charging times of today's batteries. This is a challenge to customer acceptance of a pure electric vehicle, even for a city car application. A Range Extender concept could achieve the desired customer acceptance, but should not impact the “electric driving” experience, and should not cause further significant increases in the manufacturing and purchasing cost. The V2 engine concept presented in this paper is particularly suited to a low cost, modular vehicle concept. Advantages regarding packaging can be realized with the use of two generators in combination with the V2 engine.