Automotive Propulsion Systems Research Articles

Implementation strategy for launch and performance improvement of high throughput manufacturing inspection systems

Product technologies are changing rapidly in advanced automotive propulsion systems. These products are driving the need for new manufacturing processes and new inspection methods. To keep new propulsion systems affordable and ensure these new products are introduced with high quality, automotive manufacturers are seeking automated inspection solutions with low cost and near-zero error rates to inspect 100% of the items. In this paper, a progressive deployment strategy of a hybrid inspection system is presented and studied in the context of technology development and rapid deployment. It enabled us to begin with human inspection and gradually phase-in automated inspection technology, while almost never failing to identify a bad item. This strategy was applied successfully to inspect ultrasonic welds in lithium ion battery packs. At the time of this study, a 75% reduction in human inspection was achieved with prospects for further reduction. Actual results from the implementation of this strategy in production are presented. Recommendations are made regarding the most appropriate time to employ this strategy and how it could increase the use of advanced automated in-line inspection technologies.

A REVIEW OF EGR APPLICATION FOR AUTOMOTIVE INDUSTRY

Exhaust gas recirculation (EGR) has been widely adopted as an effective strategy to reduce harmful emissions and improve fuel efficiency in internal combustion engines. This review paper aims to provide a comprehensive analysis of the utilization of EGR in various types of internal combustion engines. The review covers the principles of EGR operation, its effects on engine performance, emission reduction capabilities, challenges, and prospects. By evaluating the existing literature and research findings, this paper seeks to offer insights into the potential of EGR as a crucial technology for sustainable and environmentally friendly auto-motive propulsion systems.

CONTROL VARIATE POLYNOMIAL CHAOS: OPTIMAL FUSION OF SAMPLING AND SURROGATES FOR MULTIFIDELITY UNCERTAINTY QUANTIFICATION

We present a multifidelity uncertainty quantification numerical method that leverages the benefits of both sampling and surrogate modeling, while mitigating their downsides, for enabling rapid computation in complex dynamical systems such as automotive propulsion systems. In particular, the proposed method utilizes intrusive generalized polynomial chaos to quickly generate additional information that is highly correlated with the original nonlinear dynamical system. We then leverage a Monte Carlo-based control variate to correct the bias caused by the surrogate approximation. In contrast to related works merging adaptive surrogate approximation and sampling in a multifidelity setting, the intrusive generalized polynomial chaos (gPC) surrogate is selected because it avoids statistical errors by design by providing analytical estimates of output statistics. Moreover, it enables theoretical contributions that provide an estimator design strategy that optimally balances the computational efforts allocated to sampling and to gPC construction. We deploy our approach to multiple numerical examples including simulations of hybrid-electric propulsion systems, where the proposed estimator is shown to achieve orders-of-magnitude reduction in mean squared error of statistics estimation under comparable costs of purely sampling or purely surrogate approaches.

Electrified Automotive Propulsion Systems: State-of-the-Art Review

The increase in pollution and carbon dioxide in the transportation sector motivates many countries to establish rules to reduce the emission and carbon footprint. The partial or total electrification of the automotive propulsion system is mandatory to minimize the impact of transportation on the environment. There are multiple possible architectures to electrify the vehicle propulsion system, with different degrees of electrification, and each of the architectures can provide a different balance between energy efficiency, vehicle performance, comfort, drivability, and safety. This article aims to present the definition of the automotive propulsion system electrification, the various degrees of electrification and operation modes, and the possible configurations of an electrified propulsion system by the electric machine position. This article also introduces the definition of the subsystems of the propulsion systems and their components, with an explanation of the subsystem and each of their parts. Based on the state-of-the-art technology development, it intends to present the industry’s common sense and knowledge on automotive propulsion system electrification and proposes a process to follow in the electrified propulsion system architecture selection.

A Polynomial-Chaos-Based Multifidelity Approach to the Efficient Uncertainty Quantification of Online Simulations of Automotive Propulsion Systems

Abstract As a result of the increasing system complexity and more strict performance requirements, intelligent and robust decision-making and control capabilities are of great importance for future automotive propulsion systems. Due to the significant uncertainties from both unavoidable modeling errors and probabilistic environmental disturbances, the ability to quantify the effect of these uncertainties on system behaviors plays a crucial role in enabling advanced control designs in the future for propulsion systems. However, quantifying uncertainties in complex nonlinear systems can cause significant computational burdens. Given the limited computing power on-board a vehicle, developing algorithms with high enough efficiency to quantify uncertainties in automotive propulsion systems in real-time is a major challenge. Traditional uncertainty quantification methods for complicated nonlinear systems, such as Monte Carlo, often rely on sampling — a computationally prohibitive process in many applications. Previous research has shown promises in using spectral decomposition methods such as generalized polynomial chaos to reduce the online computational cost of uncertainty quantification. However, such method suffers from poor scalability and bias issues. In this article, we seek to alleviate these computational bottlenecks by using a multifidelity approach that utilizes Control Variate to combine generalized polynomial chaos with Monte Carlo. Results on the mean, variance, and skewness estimations of vehicle axle shaft torque show that the proposed method corrects the bias caused by Polynomial Chaos expansions while significantly reducing the overall estimator variance compared to that of a conventional Monte Carlo estimator.

The attractiveness of university and corporate anchor tenants in the conception of a new cluster

ABSTRACT Using an ex-ante, policymaker perspective, this study focuses upon a proposal for a new university (automotive) research institute (URI) – the University of Bath’s Institute for Advanced Automotive Propulsion Systems (IAAPS) – and its role in the conception of a new industrial cluster. Analysing unique survey data, we identify the key characteristics of the firms most likely to observe future potential benefits from the presence of this proposed public anchor (1) in isolation and (2) when the proposed public anchor is established with a research-based relationship with a co-located private anchor. We find the presence of a private anchor amplifies the attractiveness of the public anchor, heightening the likelihood of a cluster emerging. We discuss implications for policy.

Energy conversion in motor vehicles.

The portfolio of the automotive market appears more and more low-emission and zero-emission propulsions in vehicles. This is the result of measures taken to limit or even eliminate the emission of harmful substances into the atmosphere generated by vehicles. The article covers issues related to energy conversion in automotive drive systems currently offered by automotive manufacturers. Standard, hybrid, hybrid plug-in, electric and fuel cells drive system were analyzed. Attention was drawn to the chain of energy transformations related to each of the analyzed drive systems. The efficiency of the presented vehicle drive systems was analyzed. General conclusions were formulated regarding the method of analyzing energy changes related to the operation of automotive propulsion systems. The article reviews selected author's own works on hybrid and hydrogen propulsions.

Comparative global warming impact and NOX emissions of conventional and hydrogen automotive propulsion systems

With the rise of cleaner technologies for transport and the emergence of H2 as a fuel, most of the emissions in the well-to-wheel process are shifting towards the energy carrier production (fuel or electricity). The objective of this study is to perform a simplified cradle-to-grave Life Cycle Assessment (LCA) that compares the greenhouse gases (GHG) and NOX emissions of H2, electric and conventional technologies for the automotive sector in Europe and to devise the optimum strategy of vehicle fleet renewal to reduce the emissions. In this study the effect of water as GHG was considered and, unless other studies, the current European energy mix and that meeting the objectives for 2050 were considered (while technology level was kept constant) since H2 from electrolysis and electric vehicles’ well-to-wheel emissions are sensitive to the energy mix. To estimate the emissions, the fuel, vehicle production and operation cycles were considered independently for each technology and then put together. For H2, the best production and distribution strategy was steam methane reforming (SMR) with CO2 sequestration for GHG-100 gases and without capturing CO2 for NOX, both with central plant production and tube trailer transport. Fuel cell vehicles (FCV) with optimum H2 production always produce the lowest GHG-100 emissions and slightly higher NOX than battery electric vehicles (BEV) in the EU 2050 scenario. In contrast, HICEV would need to reach a fuel consumption of around 30 kWh/100 km to be competitive in emissions against BEV, for that, direct injection (DI) combined with a range extender (REx) hybrid architecture is the recommended powerplant concept. Finally, the optimum strategy to reduce emissions that Europe could follow is presented for the short, mid and long term.

Efficient Ni(OH)2 Supported Ultra-Low Content of Pt Electrocatalyst for Ethanol Oxidation in Alkaline Solution

Background: Direct ethanol fuel cells have gained considerable attention as promising sustainable green power sources for portable electronic devices and automotive propulsion systems. The electrocatalyst is one of the key parameters in DEFCs. However, the current electrocatalyst still suffers from high price due to a relatively large amount of noble metal used, or relatively low activity if non-noble metal was employed. Therefore, the design and fabrication of high-efficient electrocatalyst with low-content of noble metal is still of interest. Methods: Methods: Ni(OH)2 nanoflakes supported ultra-low content of Pt (Pt/Ni(OH)2) electrocatalyst was obtained via microemulsion, impregnation and chemical reduction processes. The Pt/Ni(OH)2 electrocatalyst was characterized by SEM, TEM, XRD and FTIR, and its performance for ethanol electro- oxidation was evaluated by cyclic voltammetry, Tafel and current-time curves. Results: TEM result showed that Pt NPs with sizes of ca. 4-6 nm were highly dispersed on the Ni(OH)2 nanoflakes, indicative of the successful preparation of Pt/Ni(OH)2. No peaks related to Pt NPs were observed in the XRD pattern of Pt/Ni(OH)2, revealing a low content and/or high dispersion of Pt NPs. The electrochemical investigation showed that the Pt/Ni(OH)2 electrode presented a superior catalytic performance and stability for ethanol electro-oxidation in alkaline solution. Conclusion: The Pt/Ni(OH)2 electrode with nominal 0.62 wt.% of Pt was successfully synthesized and showed an excellent catalytic activity and stability toward ethanol electro-oxidation mainly due to its porous structure, high dispersion of Pt and formation of NiOOH facilitating oxidation of ethanol. The acetate species was the major product during ethanol electro-oxidation.

Parametric study and optimization of the main engine calibration parameters and compression ratio of a methane-diesel dual fuel engine

The increasing energy demand together with the severe emission legislation of the transportation sector requires effective solutions for automotive propulsion systems. Several studies are conducted to further develop the internal combustion engines and they are mainly oriented to the application of alternative combustion concepts combined with the use of alternative fuels. The main concerns are the efficiency, the pollutant, and the carbon dioxide (CO2) emissions. In this framework, the potential of the Dual Fuel (DF) concept is demonstrated. The methane – diesel DF application permits the reduction of the CO2 emissions and the diesel fuel usage while improving the NOx – PM trade-off compared to the conventional diesel combustion (CDC).The paper investigates the effects of the engine calibration parameters on the DF combustion characteristics, regulated emissions, and global performances. The parametric analysis was performed while varying the compression ratio (CR), the methane substitution ratio, fuel injection pressure, diesel pilot quantity, combustion phasing, Exhaust Gas Recirculation (EGR) and the Air-Fuel ratio (A/F). The tests were conducted utilising a modern combustion system architecture applied on a single cylinder engine.The analysis is performed at low-medium operating conditions that are more critical for the application of the advanced combustion concepts. In particular, four engine operating test points were selected, two engine speeds (1500, 2000 rpm) and loads (3, 7 bar of imep).The results show a significant impact of the CR, EGR and A/F ratio variables on the unburned hydrocarbons reduction (up to 40%) compared to the DF baseline. Benefits in terms of CO2 and particles distributions are shown with respect to the CDC. The CH4 slip on greenhouses gas (GHG) and the emissions and fuel consumption estimation over the New European Driving Cycle (NEDC) are considered. The information reported in this paper has a relevant impact on the development advanced combustion engines running under natural gas – diesel dual fuel combustion mode and transferable in modern light-duty engines, giving as output the main engine calibration parameters and CR that most influence the efficiency and pollutant emissions formation in a DF engines.

Novel Switched Reluctance Machine Configuration With Higher Number of Rotor Poles Than Stator Poles: Concept to Implementation

There is a great demand for efficient, quiet, reliable, and cost-effective motor drives for propulsion systems in hybrid and plug-in hybrid electric vehicles. Owing to a rigid structure and the absence of magnetic source on the rotor, a switched reluctance machine (SRM) is inherently robust and cost effective. In spite of these advantages, several challenges in the control of this machine remain an issue, including high levels of torque ripple, acoustic noise, and a relatively low torque density. This paper presents a new family of SRMs which have higher number of rotor poles than stator poles. Using a newly defined pole design formula, several novel combinations of the stator-rotor poles have been proposed. From the simulation and experimental analysis of a prototype 6/10 configuration, it has been observed that this machine produces higher torque per unit volume and comparable torque ripple when compared to a conventional 6/4 SRM with similar number of phases and constraints in volume. The results presented in this paper make this family of machines a strong contender for survivable high-performance applications for automotive propulsion systems. The simulation and experimental results for the prototype 6/10 configuration have been presented and compared to a conventional 6/4 design for verification.

DTC of an FSTPI‐fed induction motor drive with extended speed range

PurposeThe purpose of this paper is to analyze the performance of a new direct torque control (DTC) strategy dedicated to four‐switch three‐phase inverter (FSTPI)‐fed induction motor drives with extended speed range.Design/methodology/approachThe approach is based on the synthesis of a suitable vector selection table in order to reduce torque ripple. The performance analysis is carried out based on three criteria: the total harmonic distortion; the switching loss factor; and the quality factor.FindingsIt has been clearly shown that the introduced DTC strategy offers high performance during both transient and steady‐state operations of the FSTPI‐fed induction motor drive, which are almost the same as those yielded by the Takahashi DTC strategy implemented in the same motor fed by a conventional six‐switch three‐phase inverter (SSTPI).Research limitations/implicationsThe work should be extended by an experimental validation of the simulation results.Practical implicationsThe established results open up crucial benefits from the point of view of cost‐effectiveness and volume‐compactness of induction motor drives especially in large‐scale industries such as the automotive, where electric and hybrid propulsion systems are currently regarded as an interesting alternative to substitute or to assist the thermal propulsion systems.Originality/valueThe paper presents the implementation of a dedicated DTC strategy in FSTPI‐fed induction motor drives with extended speed range. The proposed DTC strategy offers interesting performance compared with that yielded by the Takahashi DTC strategy implemented in the same motor fed by an SSTPI.

Diesel perspective in global market vision

The article describes some predictions with regard to developing trends of automotive propulsion systems. According to the author’s opinion, Diesel engines will share with the gasoline one the leadership of the market in the short-to-middle timeframe, with shares depending mainly from regional contingencies. In the middle-to-long timeframe, the hybrid powertrain and fuel cells will became a real alternative option to conventional engine. However, Diesel hybrid powertrain could also became a very interesting opportunity, because the Diesel engine features will further improve the fuel consumption and the fun-to-drive features of hybrid systems.

Performance of CO preferential oxidation reactor with noble-metal catalyst coated on ceramic monolith for on-board fuel processing applications

On-board fuel processors are being developed to provide hydrogen-rich gas to the polymer electrolyte fuel cell automotive propulsion systems. Whereas the anode catalyst in the fuel cell has low tolerance for carbon monoxide, 10–100 ppm, reforming of gasoline and other hydrocarbon fuels generally produces 1–2% of CO. Of the many methods of removing CO from the reformer gas, preferential oxidation (PrOx) of CO over noble-metal catalysts is practiced most frequently. In this paper, we present experimental data for CO conversion on a Pt-based catalyst that is active at room temperature and was coated on a ceramic monolith. The data is used to develop an empirical correlation for selectivity for CO oxidation as a function of CO concentration and oxygen stoichiometry at 30,000–80,000/h space velocity. The selectivity correlation is used in a model to analyze the performance of multi-stage, adiabatic PrOx reactors with heat exchange between the stages to cool the reformate to 100 °C. An optimization algorithm is used to determine the operating conditions that can reduce CO concentration to 10 ppm while minimizing parasitic loss of H 2 in the reformate stream. It is found that the 10 ppm constraint limits the maximum inlet CO concentration to 1.05% in a single-stage reactor and to 3.1% in a two-stage reactor. The results clearly show the incremental reduction in parasitic H 2 loss by addition of second and third stages.

Torque distribution control unit in automotive propulsion systems

Torque distribution control unit in automotive propulsion systems

Issues in Energy Storage for Electric-Based Transportation

AbstractThe key to market success for electric vehicles (EVs) has always been the energy-storage device, which limits driving range and vehicle acceleration. In many respects, rechargeable lithium batteries are the most attractive technology for storing energy and delivering it on demand in an automobile. Past and ongoing efforts to develop electric-based automotive propulsion systems are chronicled in this article.

Power transmission of a cone roller toroidal traction drive. (1st report Speed and torque transmission efficiencies)

A continuously variable transmission (CVT) will contribute to improve the fuel economy of automotive propulsion systems The half toroidal traction drive is a rolling element type CVT with a feature of low spin in contact area. In this report, a theoretical estimation method of speed and torque transmission efficiencies is shown by making a shear model of traction fluid in EHL contact area. Theoretical results are compared to test results of a prototype of nominal input torque capacity of 120 N·m, rotational speed of 5000 rpm and maximum speed ratio of 6.25.

Economic impact of mass production of alternative low emission automotive power systems.

The study considers a range of possible effects on the transportation industry, satellite industries, the labor market, and the economy which may be anticipated in the event mass production of unconventional low emission automotive propulsion systems should occur, whether as a consequence of federal intervention, or not. A postulated 1 976 Otto Cycle Internal Combustion Engine equipped with a dual catalyst manifold reactor and other “conventional” emission control devices was compared in detail with a Regenerative Free Turbine Engine and a Rankine Cycle Engine, as specified by the contracting agency. Manufacturing costs, operating and ownership costs, consumer demand, inter-industry effects, employment, resource requirements, and international trade implications were analyzed in depth under a number of plausible sets of policy constraints and parametric variations. Principal conclusions are that conversion over a 10 year period is feasible, that manufacturing cost differentials are less critical than fuel...