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Implementing triple injection strategies in partially premixed charge-based gasoline compression ignition (GCI) engines has shown to achieve improved engine efficiency and reduced NOx and smoke emissions in many previous studies. While the impact of the triple injections on engine performance and engine-out emissions are well known, their role in controlling the mixture homogeneity and charge premixedness is currently poorly understood. The present study shows correspondence between the triple injection strategies and mixture homogeneity/premixedness through the experimental tests of second/third injection proportion and their timing variations with an aim to explain the observed GCI engine performance and emission trends. The experiments were conducted in a single cylinder, small-bore common-rail diesel engine fuelled with a commercial gasoline fuel of 95 research octane number (RON). While the first injection proportion and timing were fixed at 40% and 170 °CA bTDC, the second injection proportion was varied from 5~20% (i.e. third injection of 40~55%) and the timing was varied from 20 to 80 °CA bTDC. The third injection timing was also swept from 2 to 11 °CA bTDC. The results show that increased second injection proportion causes higher peak in-cylinder pressure and apparent heat release rate (aHRR) due to increased charge premixing. This leads to lower smoke emissions but increased combustion-induced noise and NOx emissions. Despite higher peak in-cylinder pressure, the engine efficiency shows a decreasing trend with increased second-injection proportion because of the increased wall-wetting and lower late-cycle pressure. Advanced second injection timing leads to lower peak in-cylinder pressure and aHRR and thereby decreasing engine efficiency, which is associated with the increased mixture homogeneity. Consequently, the smoke/NOx and combustion-induced noise emissions are reduced while the uHC emissions become higher, similar to homogeneous charge compression ig

The present study aims to evaluate the effects of engine speed ongasoline compression ignition (GCI) combustion implementingdouble injection strategies. The double injection comprises ofnear-BDC first injection for the formation of a premixed charge andnear-TDC second injection for the combustion phasing control. Theengine performance and emissions testing of GCI combustion hasbeen conducted in a single-cylinder light-duty diesel engine equippedwith a common-rail injection system and fuelled with a conventionalgasoline with 91 RON. The double injection strategy was investigatedfor various engine speeds ranging 1200~2000 rpm and the secondinjection timings between 12°CA bTDC and 3°CA aTDC. From thetests, GCI combustion shows high sensitivity to the second injectiontiming and combustion phasing variations such that the advancedsecond injection causes advanced combustion phasing and extendedpre-combustion mixing time, and thereby increasing engineefficiency and decreasing ISFC. This leads to the reduced smoke/uHC/CO emissions but increased combustion noise and NOxemissions, similar to the trends in conventional diesel combustion. Itis found that the increased engine speed requires a higher fuel massper injection to maintain similar IMEP values, leading to lowerefficiency, higher ISFC, and increased combustion noise. The heatrelease rate increases with increasing engine speed but thecombustion phasing is largely unchanged. A typical smoke-NOxtrade-off is found with increased smoke and decreased NOx emissionsat higher engine speed, primarily due to reduced charge premixingtime, which suggests the partially premixed charge-based GCIcombustion behaves similar to conventional diesel combustion withoverall lower smoke and NOx emissions.

Interest in the use of kerosene fuel in diesel engines has garnered researchers’ attention in the past few years due to its improve premixed combustion and its ability to decrease soot emission. The potential of using kerosene in the design stage of a diesel engine is thus a great motivator to study fuel spray development and to evaluate known fuel spray tip correlations and models with respect to their predictive capability with such a fuel. Therefore, the present paper proposes to investigate the spray development of a multi-hole solenoid injector fueled with kerosene under non-evaporative conditions. Moreover, the experimental results are used to evaluate how different phenomenological models proposed in the literature for diesel fuel are able to predict kerosene spray tip penetration. The experimental test rig is composed of a constant-volume pressurized vessel and a camera allowing to visualize the liquid phase using a backlight illumination technique. The influence of the injection pressure is studied at 400, 800 and 1600 bar, while three different injection durations (0.5, 1, and 2 ms) and five ambient pressures (2.5, 5, 10, 15 and 20 bar) are investigated. The experimental results are presented using a nondimensional time and fuel spray tip penetration to facilitate the analysis. The results show, as expected, that increasing the injection pressure or decreasing the ambient pressure results in a faster fuel spray tip penetration. The models that are evaluated include a constant ambient density hypothesis formulation, a variable ambient density model and three empirical correlations. A comparison between the models and experimental results shows that low injection pressure and short injection duration are two conditions in which the models have difficulty to predict the fuel spray tip penetration. Overall, the best performance was offered by the variable density model, which predicted the experimental data well.

Turbocharger testing is a time consuming process, and as rapid-prototyping technology advances, so must other areas in the development chain. As an example, in one study a compressor map took over 34 hours to measure. In this paper, an effort to combat the main bottleneck of turbocharger testing, namely the thermal inertia, is made. When changing operating point during the measurement process, several minutes can be required before the turbocharger components reach temperature steady state. In an earlier paper, a method based on non-linear trajectory optimization was developed that significantly reduced the testing time required to produce compressor performance maps. The time was reduced by a factor of over 60, compared to waiting for the system to reach steady state with constant inputs. However, the method required a model of the turbocharger. This paper extends the method with system identification and model predictive control (MPC). This is an important step in order to use the optimal control method when only geometric information of the turbocharger is known, such as new prototypes. To demonstrate the effectiveness of the combination of system identification, non-linear trajectory optimization and MPC, the control strategy is applied to a virtual gas-stand implemented as a Simulink model, based on data from a Mitsubishi TD04 turbocharger. The data that was used to create the model was originally collected at Saab Automobile in Trollhättan, 2011. The results show that system identification captures the turbocharger behavior. Trajectory optimization finds a set of time optimal input trajectories. MPC successfully tracks the generated references. Real time implementation of the Matlab/Simulink based algorithm is planned for experimental testing.

E-motors are characterized by their high-frequency content. This brings a new challenge for a technology such as Component-based Transfer Path Analysis. This paper will intend to show how this modular methodology has been applied for a wiper e-motor. The source is characterized in-situ by a set of blocked forces and alternatively with pseudo forces. Afterward, the independent loads are converted to contact forces using a Frequency Based Substructuring technique, allowing assembly definition and target prediction on a different receiver. Finally, the predicted vibrations on the target assembly are compared to the measured one for validation purposes. A dedicated high-frequency shaker was developed to meet the required data quality. In this way the substructuring technique was applicable in a wide frequency range up to 5 kHz. © 2021 SAE International. All Rights Reserved., QC 20220525

Bus drivers are a group at risk of often suffering from musculoskeletal problems, such as low-back pain, while bus passengers on the last-row seats experience accelerations of high values. In this paper, the contribution of K-seat in decreasing the above concern is investigated with a detailed simulation study. The K-seat model, a seat with a suspension that functions according to the KDamper concept, which combines a negative stiffness element with a passive one, is benchmarked against the conventional passive seat (PS) in terms of comfort when applied to different bus users' seats. More specifically, it is tested in the driver's and two different passengers' seats, one from therear overhang and one from the middle part. For the benchmark shake, both are optimized by applyingexcitations that correspond to real intercity bus floor responses when it drives over a real road profile. Then a human model is placed on the seats in order to compare their optimum solutions in terms of the user's whole-body vibrations (WBVs), using objective comfort metrics. Based on the results, the K-seat improves significantly the comfort of the users (~92%) compared to the PS, while it achieves a similar decrease in the maximum values of the user's back accelerations (~97%)., QC 20211216QC 20220315

Thermoacoustic engine has been proven to be a promising technology for automotive exhaust waste heat recovery to save fossil fuel and reduce emission thanks to its ability to convert heat into acoustic energy which, hence, can be harvested in useful electrical energy. In this paper, based on the practical thermodynamic parameters of the automotive exhaust gas, including mass flow rate and temperature, two traveling-wave thermoacoustic engines are designed and optimized for the typical heavy-duty and light-duty vehicles, respectively, to extract and reutilize their exhaust waste heat. Firstly, nonlinear thermoacoustic models for each component of a thermoacoustic engine are established in the frequency domain, by which any potential steady operating point of the engine is available. Then, a matching between the required heat for the engine and the available heat from the exhaust gas is performed to determine the practical operating point and the performance of the thermoacoustic engine driven by this exhaust gas with a specified thermodynamic state. Furthermore, an outline-size optimization of the thermoacoustic engines is carried out for the heavy-duty and light-duty applications, respectively, to improve the waste heat utilization efficiency and maximize the acoustic power. To consider the impact of the system weight on vehicles, a power-to-weight ratio is adopted in this work as the optimization objective. It's shown that the optimum system outside diameters for the heavy- and light-duty applications are different due to the different thermodynamic characteristics of the exhaust gas. The available acoustic powers with the maximum power-to-weight ratio for heavy- and light-duty applications are approximately 515 Watts and 935 Watts with 8.2% and 18% of thermal efficiency, respectively, corresponding to 29.3% and 42.9% of their respective Carnot efficiencies. The resulted CO2 emission reductions are approximately 0.37 kg/h and 0.77 kg/h, respectively., QC 20220309

In this paper, a High-Temperature Electrical Low-Pressure Impactor (HT-ELPI+) was used to measure particles from a light-duty direct injected spark ignited (DISI) engine fueled with gasoline and ethanol. The HT-ELPI+ measured volatile and non-volatile particle emissions down to 6 nm without the need for dilution. Particle emissions were measured at four operating points while sweeping the end of injection, and at idle operation. The total particle number (PN) and particle size distribution (number and mass) for both non-volatile and volatile emissions were measured with the HT-ELPI+ and compared to the measured PN using two 71.4 times diluted Condensation Particle Counters (CPCs) with two different cut-off sizes, with 23 nm and 7 nm cut-off, respectively. The results show an increase in particle emissions in terms of particle mass and total particle number for ethanol compared to gasoline. The difference in soot mass emissions is small between the fuels. However, PN shows a significant increase for ethanol, especially at low engine speed due to a deterioration in the evaporation, mixture formation and air entrainment of ethanol. A majority of the emitted particles exhibit particle sizes below 23 nm, wherein the highest numbers occurred below 10 nm. At steady-state operation, no clear difference was observed between the diluted and undiluted measurements. On the contrary, a significant difference is detected between the undiluted and diluted measurements of ethanol at idle. These observations could indicate a greater significance of dilution at lower exhaust gas temperatures and mass flow rates or when a large number of nucleation mode particles are emitted from the engine., QC 20210518, Framtida Alternativa Transportbränslen

The assembly of threaded fasteners may seem straightforward. However, there are many factors to consider to achieve quality tightened joints, including the joint material, threaded fastener, and coatings. Additionally, there are many assembly tool types and torque application strategies to choose from. This investigation studies the tightening speed dynamics when using torque as a control method. The clamp force obtained in the joint changes when tightening at high speed or when the speed varies greatly during tightening. This type of tightening is called highly dynamic. Highly dynamic torque control tightening strategies are studied, such as impact, pulse, and inertia-controlled methods, and compared with the continuous drive strategy, which is a standard dynamic torque tightening method. The clamp force and its scatter caused by the torque accuracy in the assembly tool type are investigated for the abovementioned torque application strategies. The study also focuses on the different results obtained from the International Organization for Standardization’s (ISO) 16047:2005 (Fasteners-Torque/clamp force testing) standard compared to a production-like setup., SAE Technical Paper 2021-01-5073

Renewable fuels from different feedstocks can enable sustainable transport solutions with significant reduction in greenhouse gas emissions compared to conventional petroleum-derived fuels. Nevertheless, the use of biofuels in diesel engines will still require similar exhaust gas cleaning systems as for conventional diesel. Hence, the use of diesel particulate filters (DPF) will persist as a much needed part of the vehicle's aftertreatment system. Combustion of renewable fuels can potentially yield soot and ash with different properties as well as larger amounts of ash compared to conventional fossil fuels. The faster ash build-up and altered ash deposition pattern lead to an increase in pressure drop over the DPF, increase the fuel consumption and call for premature DPF maintenance or replacement. Prolonging the maintenance interval of the DPF for heavy-duty trucks, having a demand for high up-Time, is highly desirable. Understanding the mechanisms of ash formation and build-up in the DPF, especially for renewable fuels, is therefore of uttermost importance. Techniques using accelerated ash accumulation methods offer a way to cut down on the costly and time consuming field tests, as well as offering a robust method to perform tests under conditions relevant for real-driving. This paper presents a literature review regarding accelerated ash accumulation methods by summarizing these methods and giving an overview of the various rigs found in literature. Moreover, the paper outlines the strengths and weaknesses of the different methods. Furthermore, it offers a simplistic route to choose between the different techniques based on the particular research question to be addressed., QC 20210324

This paper presents experimental results concerning the distribution of the refrigerant R134a in the inlet header of plate evaporators in automotive air-conditioning systems, as a function of operating conditions. Typical conditions in such air-conditioning systems cover the: mass flow rates of 20-60 g/s, and inlet vapor quality at the inlet header of up to 30%. The distribution of the refrigerant is expressed as the fraction of the liquid available at the inlet. The distribution results are given with flow images (shown in the paper) followed by analysis and discussions of the results.

Modelbased systems engineering is becoming an important tool when meeting the challenges of developing the complex future vehicles that fulfill the customers and legislators ever increasing demands for reduced pollutants and fuel consumption. To be able to work systematically and efficiently it is desirable to have a library of components that can be adjusted and adapted to each new situation. Turbocharged engines are complex and the compressor model serves as an in-depth example of how a library can be designed, incorporating the basic physics and allowing fine tuning as more information becomes available. A major part of the paper is the summary and compilation of a set of rules of thumb for compressor map extrapolation. The considerations discussed are extrapolation to surge, extrapolation to restriction region, and extrapolation out to choking. Furthermore the compressor diameter is coupled to the maximum performance of the compressor such as maximum speed, mass flow, and pressure ratio. All this is a result of an analysis of a database of more than 300 compressors. The paper uses the compressor modeling to discuss how wishes for extendability and reuse of component performance influences the library design. A Modelica library named Vehicle Propulsion Library VehProLib has been developed to meet these goals by including basic components that give a starting point for modeling and at the same time allows reuse and extendablility.

Vehicle dynamics development relies on subjective assessments (SA), which is a resource-intensive procedure requiring both expert drivers and vehicles. Furthermore, development projects becoming shorter and more complex, and increasing demands on quality require higher efficiency. Most research in this area has focused on moving from physical to virtual testing. However, SA remains the central method. Less attention has been given to provide better tools for the SA process itself. One promising approach is to introduce computer-tablets to aid data collection, which has proven to be useful in medical studies. Simple software solutions can eliminate the need to transcribe data and generate more flexible and better maintainable questionnaires. Tablets’ technical features envision promising enhancements of SA, which also enable better correlations to objective metrics, a requirement to improve CAE evaluations. However, it cannot be assumed that a tablet-based solution is feasible in vehicle dynamics SA context. Any distraction might result in low SA quality and safety issues when test-drivers are subjected to high mental workload pushing the vehicles to their performance-limits. In this study, a SA tablet-software for steering feel, handling, and ride was developed and systematically evaluated versus the traditional pen-and-paper method. The results indicate that the new approach is technically feasible in this context, meets more use-cases, and the drivers’ attitude towards it is positive. It increased questionnaire completion and rating resolution while reducing the error rate and transcription time. Although attendees reported that the paper-based approach has advantages from a usability point of view, the benefits of the tablet-based approach enable further process-related advantages., QC 20170208, iCOMSA

© 2019 SAE International. All Rights Reserved. Electric vehicles are considered as one of the most popular way to decrease the consumption of petroleum resources and reduce environmental pollutions. Motor control system is one of the most important part of electric vehicles. It includes power supply module, IGBT driver, digital signal processing (DSP) controller, protection adjustment module, and resolver to digital convertor. To implement the control strategies on motor control system, a lot of practical aspects need to be taken into accounts. It includes setup of the initial excitation current, consistency of current between motor and program code, over-modulation, field weakening control, current protection, and so on. In this paper, an induction motor control system for electric vehicles is developed based on DSP. The control strategy is based on the field-oriented control (FOC) and space vector pulse width modulation (SVPWM). Speed calculation, over-modulation, field weakening control, PI controller, and fault diagnosis are also applied in this DSP algorithm. As an industry product running on a real electric bus with a 100kW induction motor, communication with vehicle control unit (VCU) by CAN bus, control system safety and PC software designed for lab experiments are also discussed. This paper focused on how to develop the advanced motor control system for electric vehicles for industrial application. The steady-state and transient performances of this motor control system are analyzed by both test-bench experiments and road experiments. Its performance is satisfactory when applied to the real electric vehicle.

With increasing demands to reduce fuel consumption and CO2 emissions, it is necessary to recover waste heat from modern Heavy Duty (HD) truck engines. Organic Rankine Cycle (ORC) has been acknowledged as one of the most effective systems for Waste Heat Recovery (WHR) due to its simplicity, reliability and improved overall efficiency. The expander and working fluid used in ORC WHR greatly impact the overall performance of an integrated engine and WHR system. This paper presents the effects of volumetric expanders on the ORC WHR system of a long haulage HD truck engine at a steady-state engine operating point chosen from a real-time road data. Performance of a long haulage HD truck engine is analyzed, based on the choice of three volumetric expanders for its WHR system, using their actual performance values. The expanders are: An oil-free open-drive scroll, a hermetic scroll and an axial piston expander with working fluids R123, R245fa and ethanol, respectively. Performance of the engine that accommodates the WHR system, with each expander and working fluid combination, is assessed based on the overall system efficiency that can be achieved through heat recovery from the engine exhaust. This simulation study is carried out using validated 0D models of the scroll expanders and performance data of the piston expander, adopted from literature, and a 1D system model of a long haulage HD truck engine encompassing a WHR system. Under the given conditions, the open-drive scroll expander (R123) leads to a higher system efficiency of 6.3% at an optimum expander speed of 3400 rpm with an estimated fuel saving of 3.6% in the vehicle under study. The hermetic scroll expander (R245fa) exhibits potential performance at higher rotational speeds; it leads to 5.4% system efficiency at 5000 rpm and 3% fuel-saving. The axial piston expander (ethanol) results in a consistent performance over a wide range of expander speeds. The effect of sizing a volumetric expander in improving the over, QC 20200702

Monitoring, modeling, prediction, and control of the braking process is a difficult task due to a complex interaction between the brake contact surfaces (disc pads and brake disc). It is caused by different influences of braking regimes and brake operation conditions on its performance. Faster and better control of the braking process is extremely important in order to provide harmonization of the generated braking torque with the tire-road adhesion conditions. It has significant influence on the stopping distance. The control of the braking process should be based on monitoring of the previous and current values of parameters that have influence on the brake performance. Primarily, it is related to the disc brake actuation pressure, the vehicle speed, and the brake interface temperature. The functional relationship between braking regimes and braking torque has to be established and continuously adapted according to the change of mentioned influencing factors. In this paper dynamic neural networks have been used for the purpose of modeling and control of the disc brake actuation pressure. Parameters of the developed dynamic neural model were used to build a program for implementation in a microcontroller. Recurrent neural networks have been implemented in 8-bit CMOS microcontroller for control of the disc brake actuation pressure. Two different models have been developed and integrated into the microcontroller. The first model was used for modeling and prediction of the braking torque. Based on that, the second inverse neural model, has been developed able to predict the brake actuation pressure needed for achieving previously selected (desired) braking torque value.

The combustion in a direct injected internal combustion engine is normally open-loop controlled. The introduction of cylinder pressure sensors enables a virtual combustion sensor which in turn enables closed-loop combustion control, and the possibility to counteract effects such as engine part-to-part variation, component ageing and fuel quality diversity. Closed-loop combustion control requires precise, robust and preferably cheap sensors. This paper presents an investigation of the robustness and the limitation of a knock sensor based virtual combustion sensor. This virtual combustion sensor utilize the common heat release analysis using a knock sensor based virtual cylinder pressure signal. Major virtual sensor error sources in a heavy-duty engine were identified as: the specific heat ratio model, the boost pressure and the crank angle phasing. The virtual sensor errors were quantified in relation to both the measured cylinder pressure and the total virtual sensor error. The tolerance analysis of the virtual sensor showed the signals of the crank angles 10% and 50% heat release as robust with low sensitivity to errors. An additional dependency found for the crank angle of 10% heat release was the compression ratio error. The study concluded that it is possible to estimate the mass fraction of 10% and 50% heat release accurately enough to make the virtual sensor an option for closed loop combustion control. The study was not able to prove the virtual sensor cylinder pressure signal, crank angle of burned fractions signals or total heat release signal capable of confident determination of the amount of biodiesel in fossil diesel., Conference code: 134884; Export Date: 9 May 2018; Conference Paper. QC 20180516

When electrifying the powertrain, there arises an opportunity to revise the traditional turbocharging trade-off between fuel-economy and transient performance. With the help of electrification, it might be possible to make the trade-off in favor of fuel economy, since transient response can be improved by the electric machine. The paper investigates this trade-off by looking at three turbocharger selections. A conventionally dimensioned turbocharger, an efficiency optimized turbocharger with maintained flow capacity, and an efficiency optimized turbocharger with increased flow capacity. The concepts are evaluated on the following cases: stationary operation, engine tip-in performance, vehicle acceleration performance, and on road fuel economy performance. The investigation is based on a validated mean value engine model of a six cylinder inline CI engine, and on a validated driveline and vehicle model of a heavy-duty truck. The evaluations are made with the help of simulations and numerical optimal control. The results show that there is a fuel saving potential, and that the transient response is improved by the electric machine.

Batteries are useful in Fuel Cell Hybrid Electric Vehicles (FCHEV) to fulfill transient demands and for regenerative braking. Efficient energy management strategies paired with optimal powertrain design further improves the efficiency. In this paper, a new methodology to simultaneously size the propulsive elements and optimize the power-split strategy of a Range Extended Battery Electric Vehicle (REBEV), using a Polymer Electron Membrane Fuel Cell (PEMFC), is proposed and preliminary studies on the effects of the driving mission profile and the auxiliary power loads on the sizing and optimal performance of the powertrain design are carried out. Dynamic Programming is used to compute the optimal energy management strategy for a given driving mission profile, providing a global optimal solution. The component sizing problem is performed using a machine learning based, guided design space exploration to find the set of Pareto-optimal solutions that give the best trade-offs between the different objectives. The powertrain model includes the dynamic behavior of the fuel cell system compressor and a battery lumped parameter thermal model along with the quasi-static semi-empirical model of the fuel cell and a zero-order battery model. Initial results indicate an increase in the Pareto-optimal sizes with the inclusion of thermal management.

Wear of brake friction materials were found to be a complex combination of abrasion, adhesion, fatigue, delamination, and thermal decomposition. Stochastic nature of wear of brake friction materials is result of these wear mechanisms and their transition from one combination to another. The dominant wear mechanism of brake friction materials is influenced by braking regimes and friction material characteristics. Regarding friction material characteristics, the most important influences are related to its formulation and manufacturing conditions. Prediction of friction materials wear versus their manufacturing conditions can be considered as an important issue for further friction materials development. In this paper, the artificial neural network abilities have been used for predicting wear of the friction materials versus synergistic influence of: (i) mass percentages of phenolic resin, fibers, abrasives, and lubricants in formulation of the friction materials, (ii) work done by brake application, (iii) brake interface temperature, and (iv) friction materials manufacturing conditions (moulding pressure, moulding time, moulding temperatures, heat treatment time, and heat treatment temperatures). The model of the friction materials wear has been developed able to predict how manufacturing conditions of the friction material influence its wear in synergy with different mass percentages of key ingredients in the friction material formulations at different brake interface temperatures.

Prediction of the brake friction material performance versus changes of its composition, manufacturing, and operation conditions is considered as an important step in the friction materials development. Due to complex synergy effects of these influencing factors on the friction coefficient stability, an analytical model of the brake friction materials performance is difficult to obtain. That is why in this paper artificial neural networks have been used for modelling and predicting the effects of these influencing factors on the brake friction materials speed sensitivity. A two hidden-layer neural network model, trained by the Bayesian Regulation algorithm, has been developed with inherent abilities to generalize the complex influences on the speed sensitivity performance of the brake friction materials.

The demands imposed on a braking system of passenger cars, under wide range of operating conditions, are high and manifold. Improvement of automotive braking systems' performance, under different operating conditions, is complicated by the fact that braking process has stochastic nature. The automotive brake's performance primarily affected the braking system's performance because their performance results from the complex interrelated phenomena occurring in the contact of the friction pair. These complex braking phenomena are mostly affected by the physicochemical properties of friction materials ingredients, its manufacturing conditions, and brake's operation regimes. Analytical models of brakes performance are difficult, even impossible to obtain due to complex and highly nonlinear phenomena involved during braking. That is why, in this paper all relevant influences on the disc brake operation of a passenger car have been integrated by means of artificial neural networks. The influences of the friction material's composition (18 ingredients), its manufacturing conditions (5 parameters), and brake's operation regimes (application pressure, initial speed, and temperature in the contact of friction pair) have been modelled versus changes of the brake factor C i.e. coefficient of the friction. The artificial neural network's model of the disc brake operation has been used for their intelligent controlling. Based on an optimal neural model of the disc brake operation, the neural network's controller of disc brake operation can be developed. The intelligent control of the brake's operation has been related to adjusting of application pressure of the disc brakes. Accordingly, the brake's performance would be adjusted on the level that corresponds to driver's demanded deceleration taking into consideration the history of brake's performance represented by the neural model.

The neural computation ability to model complex non-linear relationships directly from experimental data, without any prior assumptions about nature of the input/output relationships, has been used in this paper. An artificial neural network technique was used to develop a neural model for predicting the friction materials behavior under prescribed testing conditions. By means of neural modeling of the friction materials behavior, the relationship between 26 input parameters and one output parameter (brake factor C) has been established. The input parameters are defined by the friction material formulation (18 parameters), manufacturing conditions (5 parameters), and testing conditions (3 parameters). Prediction abilities of the neural model have been evaluated by comparison the real cold performance obtained during friction material testing on the single end full-scale inertia dynamometer and predicted ones.

With the advent of ISO 26262 there is an increased emphasis on top-down design in the automotive industry. While the standard delivers a best practice framework and a reference safety lifecycle, it lacks detailed requirements for its various constituent phases. The lack of guidance becomes especially evident for the reuse of legacy components and subsystems, the most common scenario in the cost-sensitive automotive domain, leaving vehicle architects and safety engineers to rely on experience without methodological support for their decisions. This poses particular challenges in the industry which is currently undergoing many significant changes due to new features like connectivity, servitization, electrification and automation. In this paper we focus on automated driving where multiple subsystems, both new and legacy, need to coordinate to realize a safety-critical function. This paper introduces a method to support consistent design of a work product required by ISO 26262, the Functional Safety Concept (FSC). The method arises from and addresses a need within the industry for architectural analysis, rationale management and reuse of legacy subsystems. The method makes use of an existing work product, the diagnostic specifications of a subsystem, to assist in performing a systematic assessment of the influence a human driver, in the design of the subsystem. The output of the method is a report with an abstraction level suitable for a vehicle architect, used as a basis for decisions related to the FSC such as generating a Preliminary Architecture (PA) and building up argumentation for verification of the FSC. The proposed method is tested in a safety-critical braking subsystem at one of the largest heavy vehicle manufacturers in Sweden, Scania C.V. AB. The results demonstrate the benefits of the method including (i) reuse of pre-existing work products, (ii) gathering requirements for automated driving functions while designing the PA and FSC, (iii) the parallelizati, QC 20171124

Turbocharging plays an important role in the downsizing of engines. Model-based approaches for boost control are going to increasing the necessity for controlling the wastegate flow more accurately. In today’s cars, the wastegate is usually only controlled with a duty cycle and without position feedback. Due to nonlinearities and varying disturbances a duty cycle does not correspond to a certain position. Currently the most frequently used feedback controller strategy is to use the boost pressure as the controller reference. This means that there is a large time constant from actuation command to effect in boost pressure, which can impair dynamic performance. In this paper, the performance of an electrically controlled vacuum-actuated waste-gate, subsequently referred to as vacuum wastegate, is compared to an electrical servo-controlled wastegate, also referred to as electric wastegate. Their performance is investigated with the two actuators installed on a turbocharged inline four gasoline engine in an engine test bench. Furthermore, different control synthesis designs for these different actuators are investigated. A state-feedback controller with standard models for the electric wastegate is described and implemented, which gives a position-controlled wastegate. One main difference between vacuum and electric wastegate is that the latter has a position sensor. To make an extended comparison between the solutions, the vacuum wastegate is also equipped with a position sensor and controller using standard controller design methods. The controllers are implemented and compared both in a simulation environment and evaluated in an engine test bench. In addition, for the electric wastegate, both soft-landing and tightening features are also implemented and investigated. Their aim is to improve the lifetime and behavior at or near the closed position.

Today’s need for fuel efficient vehicles, together with increasing engine component complexity, makes optimal control a valuable tool in the process of finding the most fuel efficient control strategies. To efficiently calculate the solution to optimal control problems a gradient based optimization technique is desirable, making continuously differentiable models preferable. Many existing control-oriented Diesel engine models do not fully posses this property, often due to signal saturations or discrete conditions. This paper offers a continuously differentiable, mean value engine model, of a heavy-duty diesel engine equipped with VGT and EGR, suitable for optimal control purposes. The model is developed from an existing, validated, engine model, but adapted to be continuously differentiable and therefore tailored for usage in an optimal control environment. The changes due to the conversion are quantified and presented. Furthermore, it is shown and analyzed how to optimally control the engine in a fuel optimal way under steady-state conditions, and in a time optimal way in a tip-in scenario.

As vehicles become electrified and more intelligent in terms of sensing, actuation and processing; a number of interesting possibilities arise in controlling vehicle dynamics and driving behavior. Over-actuation with in-wheel motors, all wheel steering and active camber is one such possibility, which facilitate the control strategies that push boundaries in energy consumption and safety. Optimal control can be used to investigate the best combinations of control inputs to an over-actuated system. This paper shows how an optimal control problem can be formulated and solved for an over-actuated vehicle case, and highlights the translation of this optimal solution to a real-world scenario, enabling intelligent means to improve vehicle efficiency. This paper gives an insight into Dynamic Programming (DP) as an offline optimal control method that guarantees the global optimum. Therefore the optimal control allocation to minimize an objective function and simultaneously fulfill the defined constraints can be achieved. As a case study the effects of over-actuation on the cornering resistance were investigated in two different maneuvers i.e. step steer and sine with dwell, where in both cases the vehicle assumes to be in steady state situation. In this work the cornering resistance is the main objective function and maintaining the reference trajectory is the constraint which should be fulfilled. A parameter study is conducted on the benefits of over-actuation, and depending on the type of over-actuation about 15% to 50% reduction in cornering resistance were observed during step steer and sine with dwell maneuver respectively. From a second parameter study that focused on COG position from a safety perspective, it is more beneficial for the vehicle to be designed to under-steer than over-steer. Finally, a method is described to translate the offline optimal results to vehicle implementable controllers in the form of both feed-through lookup-tables and rule-based feed-forwa, QC 20210929

Active safety of vehicle combinations during braking highly depends on braking compatibility behavior. There are different influencing factors disabling partial deceleration of individual elements of a vehicle combination to be "compatible", or balanced. The paper deals with an advanced Friction Monitoring and Control System (FMCS), which may be used in braking systems of vehicle combinations. This system is intended to improve vehicle combination braking compatibility behavior, but also braking force distribution performance of combination components by means of monitoring and controlling of braking force variations. Digital brake models are developed for this purpose. They relate analytically and/or numerically braking forces developed in individual brakes of a vehicle combination with the most dominant influencing factors, and in particular with the control pressure. That is how this advanced FMCS anticipates frictional behavior of brakes in the next brake application based on the history of precedent brake applications.

Heavy commercial vehicles constitute the dominant form of inland freight transport. There is a strong interest in making such vehicles autonomous (self-driving), in order to improve safety and the economics of fleet operation. Autonomy concerns affect a number of key systems within the vehicle. One such key system is brakes, which need to remain continuously available throughout vehicle operation. This paper presents a fail-operational functional brake architecture for autonomous heavy commercial vehicles. The architecture is based on a reconfiguration of the existing brake systems in a typical vehicle, in order to attain dynamic, diversified redundancy along with desired brake performance. Specifically, the parking brake is modified to act as a secondary brake with capabilities for monitoring and intervention of the primary brake system. A basic fault tree analysis of the architecture indicates absence of single points of failure, and a reliability analysis shows that it is reasonable to expect about an order of magnitude improvement in overall system reliability. Copyright © 2016 SAE International., QC 20161101. QC 20191016

With alternative fuels having moved more into market in light of their reduction of emissions of CO2 and other air pollutants, the spark ignited internal combustion engine design has only been affected to small extent. The development of combustion engines running on natural gas or Biogas have been focused to maintain driveability on gasoline, creating a multi fuel platform which does not fully utilise the alternative fuels' potential. However, optimising these concepts on a fundamental level for gas operation shows a great potential to increase the level of utilisation and effectiveness of the engine and thereby meeting the emissions legislation. The project described in this paper has focused on optimising a combustion concept for CNG combustion on a single cylinder research engine. The ICE's efficiency at full load and the fuels characteristics, including its knock resistance, is of primary interest - together with part load performance and overall fuel consumption. In the process of increasing the efficiency of the engine the following areas have been of primary interest, increased compression ratio, thermal load at high cylinder pressure and the use of EGR to further increase efficiency. The overall goal in the project was to reduce the CO2-emissions while maintaining the performance and characteristics of the engine. The ambition is to reduce specific tail-pipe CO2-emissions in g/kWh by 50% compared to a modern gasoline engine. The goal was close to being reached at 45% reduction at full load and 25-34% on part load. This was done by theoretically downsizing the engine and increasing the specific performance of the engine., QC 20161123

To tune the acoustics of intake systems resonators are often used. A problem with this solution is that the performance of these resonators can be affected a lot by flow. First, for low frequencies (Strouhal-numbers) the acoustic induced vorticity across a resonator inlet opening will create damping, which can reduce the efficiency. Secondly, the vorticity across the opening can also change the end-correction (added mass) for the resonator, which can modify the resonance frequency. However, the largest problem that can occur is whistling. This happens since the vortex-sound interaction across a resonator opening for certain Strouhal-numbers will amplify incoming sound waves. A whistling can then be created if this amplified sound forms a feedback loop, e.g., via reflections from system boundaries or the resonator. To analyse this kind of problem it is necessary to have a model that allows for both sound and vorticity and their interaction. This means using a convected wave equation type of model is not sufficient. A better approach is to apply the linearized Navier Stokes equations, which will give a full model of the vortex-sound effects. In this paper an effort to apply this approach on a set of generic resonators is described. Besides the numerical results comparisons with experiments are also presented., QC 20161205

Ethanol and acetaldehyde emissions from a direct ignition spark ignition were measured using mass spectrometry. Previous methods focused on eliminating or minimizing interference from exhaust species with identical atomic mass and fragment ions created in ionization process. This paper describes a new technique which exploits the fragment ions from ethanol and acetaldehyde. A survey of mass spectra of all major species of exhaust gas was conducted. It was found that ethanol contributes most ions in mass number 31 and that no other gas species produces ions at this mass number. Acetaldehyde detection suffers more interference. Nevertheless, it was estimated that detection at mass number 43 is possible with 10% error from 2-methylbutane. This new technique was validated in an engine experiment. By running the engine with pure gasoline and E85, the validity of the technique can be checked. Two conditions were investigated: idling (1200 rpm, 1.5 bar NIMEP, retarded ignition timing) and medium load (1500 rpm, 3.8 bar NIMEP, MBT ignition timing). The results from both conditions confirmed that ions were only detected when E85 was used. Furthermore, the measured ethanol concentrations agree with results obtained using gas chromatography. However, acetaldehyde was overestimated greatly. It was possibly caused by ions with atomic mass 44 being miscounted or by the fact that the interference from 2-methybutane was much bigger than calculated. Further investigation is required.

CONVENIENT is a project where prediction and integrated control are applied on several subsystems with electrified actuators. The technologies developed in this project are applied to a long-haul tractor and semi-trailer combination. A Volvo truck meeting the Eu6 emission standard is rebuilt with a number of controllable electrified actuators. An e-Horizon system collects information about future road topography and speed limits. Controllable aerodynamic wind deflectors reduce the wind drag. The tractor is also equipped with a full digital cluster for human machine interface development. A primary project goal is to develop a model-based optimal controller that uses predictive information from the e-Horizon system in order to minimize fuel consumption. Several energy buffers are controlled in an integrated and optimal way using model predictive control. Several buffers are considered, such as the cooling system, the battery, and the vehicle kinetic energy. This paper presents details on the model predictive controller of the battery system and of the cooling system. Another project goal is to reduce fuel consumption by using adaptive aerodynamics. Controllers are developed that automatically sets an optimal roof deflector angle and the optimal side deflector angle. The results presented in this paper are encouraging. A third focus is the human machine interface and especially the communication between the driver and the control system during driving. This project develops a driver interface that encourages the driver to use the adaptive cruise controller when appropriate. The CONVENIENT project will be finalized this year. This paper presents the main project findings., QC 20160210, CONVENIENT

In this paper, we present an image registration approach to cope with inter-image illumination changes of arbitrary shape in order to monitor the development of micro-pitting in transmission gears. Traditional image registration approaches do not typically account for inter-image illumination variations that negatively affect the geometric registration precision. Given a set of captured images of gear surface degradation with different exposure times and geometric deformations, the correlation between the resulting aligned images is compared to a reference one. The presented image registration approach is used with an online health monitoring system involving the analysis of vibration, acoustic emission and oil debris to follow the development of micro-pitting in transmission gears. The proposed monitoring system achieves more registration precision compared to competing systems. This paper experimentally validates the system's capabilities to detect early gear defects and reliably identify the gradual development of micro-pitting in gears, so that it could be used in predictive health monitoring (PHM) systems and overcome the disadvantages of the most commonly used methods, such as gear flank profile scanning, replica sample analysis and conventional image analysis.

In this paper, we present an image registration approach to cope with inter-image illumination changes of arbitrary shape in order to monitor the development of micro-pitting in transmission gears. Traditional image registration approaches do not typically account for inter-image illumination variations that negatively affect the geometric registration precision. Given a set of captured images of gear surface degradation with different exposure times and geometric deformations, the correlation between the resulting aligned images is compared to a reference one. The presented image registration approach is used with an online health monitoring system involving the analysis of vibration, acoustic emission and oil debris to follow the development of micro-pitting in transmission gears. The proposed monitoring system achieves more registration precision compared to competing systems. This paper experimentally validates the system's capabilities to detect early gear defects and reliably identify the gradual development of micro-pitting in gears, so that it could be used in predictive health monitoring (PHM) systems and overcome the disadvantages of the most commonly used methods, such as gear flank profile scanning, replica sample analysis and conventional image analysis.

In this paper, we present an image registration approach to cope with inter-image illumination changes of arbitrary shape in order to monitor the development of micro-pitting in transmission gears. Traditional image registration approaches do not typically account for inter-image illumination variations that negatively affect the geometric registration precision. Given a set of captured images of gear surface degradation with different exposure times and geometric deformations, the correlation between the resulting aligned images is compared to a reference one. The presented image registration approach is used with an online health monitoring system involving the analysis of vibration, acoustic emission and oil debris to follow the development of micro-pitting in transmission gears. The proposed monitoring system achieves more registration precision compared to competing systems. This paper experimentally validates the system's capabilities to detect early gear defects and reliably identify the gradual development of micro-pitting in gears, so that it could be used in predictive health monitoring (PHM) systems and overcome the disadvantages of the most commonly used methods, such as gear flank profile scanning, replica sample analysis and conventional image analysis.

[EN] Boosting technologies have been key enablers for automotive engines development through downsizing and downspeeding. In this situation, numerous multistage boosting systems have appeared in the last decade. The complexity arising from multistage architectures requires an efficient matching methodology to obtain the best overall powertrain performance. The paper presents a model aimed to choose the best 2-stage boosting system architecture able to meet required criteria on boosting pressure, EGR ratios for both short and long route loops while respecting the engine thermo-mechanical limits such as in-cylinder pressure, compressor outlet temperature and exhaust manifold temperature. The model includes filling-and-emptying 0D elements together with mean value. The engine model is set in a way that, for given requirements and boosting system layout, calculates in seconds if the requirements will be achieved and the position of variable geometry, waste-gate, EGR and by-pass valves. The model is thus inversed thanks to a new representation of turbine maps that converts the classical iterative matching procedure in straight forward. The model can be also used in a predictive manner to calculate the engine transient response. The model has been calibrated to 3 different turbocharged diesel engines. The model gives good results provided that wave effects are not important. This is the case of compact exhaust manifolds, typically used in turbocharged diesel engines, below 3500 rpm. Tuned intake air lines can be taken into account through a tuning parameter affecting boosting pressure. An example is given in the paper for the matching procedure in a 2-stage, double route EGR, including steady and transient results.

[EN] Boosting technologies have been key enablers for automotive engines development through downsizing and downspeeding. In this situation, numerous multistage boosting systems have appeared in the last decade. The complexity arising from multistage architectures requires an efficient matching methodology to obtain the best overall powertrain performance. The paper presents a model aimed to choose the best 2-stage boosting system architecture able to meet required criteria on boosting pressure, EGR ratios for both short and long route loops while respecting the engine thermo-mechanical limits such as in-cylinder pressure, compressor outlet temperature and exhaust manifold temperature. The model includes filling-and-emptying 0D elements together with mean value. The engine model is set in a way that, for given requirements and boosting system layout, calculates in seconds if the requirements will be achieved and the position of variable geometry, waste-gate, EGR and by-pass valves. The model is thus inversed thanks to a new representation of turbine maps that converts the classical iterative matching procedure in straight forward. The model can be also used in a predictive manner to calculate the engine transient response. The model has been calibrated to 3 different turbocharged diesel engines. The model gives good results provided that wave effects are not important. This is the case of compact exhaust manifolds, typically used in turbocharged diesel engines, below 3500 rpm. Tuned intake air lines can be taken into account through a tuning parameter affecting boosting pressure. An example is given in the paper for the matching procedure in a 2-stage, double route EGR, including steady and transient results.

In this paper, we present an image registration approach to cope with inter-image illumination changes of arbitrary shape in order to monitor the development of micro-pitting in transmission gears. Traditional image registration approaches do not typically account for inter-image illumination variations that negatively affect the geometric registration precision. Given a set of captured images of gear surface degradation with different exposure times and geometric deformations, the correlation between the resulting aligned images is compared to a reference one. The presented image registration approach is used with an online health monitoring system involving the analysis of vibration, acoustic emission and oil debris to follow the development of micro-pitting in transmission gears. The proposed monitoring system achieves more registration precision compared to competing systems. This paper experimentally validates the system's capabilities to detect early gear defects and reliably identify the gradual development of micro-pitting in gears, so that it could be used in predictive health monitoring (PHM) systems and overcome the disadvantages of the most commonly used methods, such as gear flank profile scanning, replica sample analysis and conventional image analysis.

In this paper, we present an image registration approach to cope with inter-image illumination changes of arbitrary shape in order to monitor the development of micro-pitting in transmission gears. Traditional image registration approaches do not typically account for inter-image illumination variations that negatively affect the geometric registration precision. Given a set of captured images of gear surface degradation with different exposure times and geometric deformations, the correlation between the resulting aligned images is compared to a reference one. The presented image registration approach is used with an online health monitoring system involving the analysis of vibration, acoustic emission and oil debris to follow the development of micro-pitting in transmission gears. The proposed monitoring system achieves more registration precision compared to competing systems. This paper experimentally validates the system's capabilities to detect early gear defects and reliably identify the gradual development of micro-pitting in gears, so that it could be used in predictive health monitoring (PHM) systems and overcome the disadvantages of the most commonly used methods, such as gear flank profile scanning, replica sample analysis and conventional image analysis.

In this paper, we present an image registration approach to cope with inter-image illumination changes of arbitrary shape in order to monitor the development of micro-pitting in transmission gears. Traditional image registration approaches do not typically account for inter-image illumination variations that negatively affect the geometric registration precision. Given a set of captured images of gear surface degradation with different exposure times and geometric deformations, the correlation between the resulting aligned images is compared to a reference one. The presented image registration approach is used with an online health monitoring system involving the analysis of vibration, acoustic emission and oil debris to follow the development of micro-pitting in transmission gears. The proposed monitoring system achieves more registration precision compared to competing systems. This paper experimentally validates the system's capabilities to detect early gear defects and reliably identify the gradual development of micro-pitting in gears, so that it could be used in predictive health monitoring (PHM) systems and overcome the disadvantages of the most commonly used methods, such as gear flank profile scanning, replica sample analysis and conventional image analysis.

In order to mitigate the effect of fossil fuels on global warming, biodiesel is used as drop in fuel. However, in the mixture of biodiesel and diesel, soft particles may form. These soft particles are organic compounds, which can originate from the production and degradation of biodiesel. Further when fuel is mixed with unwanted contaminants such as engine oil the amount soft particles can increase. The presence of these particles can cause malfunction in the fuel system of the engine, such as nozzle fouling, internal diesel injector deposits (IDID) or fuel filter plugging. Soft particles and the mechanism of their formation is curtail to understand in order to study and prevent their effects on the fuel system. This paper focuses on one type of soft particles, which are metal soaps. More precisely on the role of the short chain fatty acids (SCFA) during their formation. In order to do so, aged and unaged B10 was studied. The fuel matrixes were mixed with a calcium source such as calcium oxide (CaO), calcium carbonate (CaCO3) and engine oil. The importance of SCFA was studied by influencing the presence of the acids, by degrading the fuel, by the addition of formic acid and by inert gas bubbling. The created deposits and fuels mixtures were examined with the use of pH measurements, Fourier-transform infrared spectroscopy (FTIR), gas chromatography-mass spectrometry (GC-MS) and ion chromatography (IC). Opposed to the expectations, the results indicate that SFCA in not the most important factor for the formation of soft particles. It is shown that the calcium sources influenced the consistency and amount of the created soft particles. From the tested contaminants, CaO showed the highest yield towards precipitates. While degradation of the fuels showed to be the most important factor to form soap type soft particles., QCR 20210324

Biofuel can enable a sustainable transport solution and lower greenhouse gas emissions compared to standard fuels. This study focuses on biodiesel, implemented in the easiest way as drop in fuel. When mixing biodiesel into diesel one can run into problems with solubility causing contaminants precipitating out as insolubilities. These insolubilities, also called soft particles, can cause problems such as internal injector deposits and nozzle fouling. One way to overcome the problem of soft particles is by filtration. It is thus of great interest to be able to quantify fuel filters' ability to intercept soft particles. The aim of this study is to test different fuel filters for heavy-duty engines and their ability to filter out synthetic soft particles. A custom-built fuel filter rig is presented, together with some of its general design requirements. For evaluation of the efficiency of the filters, fuel samples were taken before and after the filters. The fuel samples were analyzed with gas chromatography-mass spectrometry (GC-MS) and x-ray fluorescence spectroscopy (XRF) to estimate the soft particle removal efficiency of each fuel filter. Furthermore, the pressure drop across the filters was measured, to provide an indication about their plugging potential. Results are presented about the concentration dependency of synthetic soft particles, both regarding pressure drop and efficiency of removal. Finally, different fuel filter materials were compared regarding their efficiency to remove soft particles. The results of this paper show the basic concepts of how soft particles can be examined in a laboratory scale fuel filter rig, and show a first estimate about the capabilities of soft particle removal by currently available fuel filters., QC 20210316

Extraction and utilization of automotive waste exhaust heat is an effective way to save fuel and protect the environment. One promising technology for this purpose is the thermoacoustic engine, where thermal energy is converted to mechanical energy in terms of high amplitude oscillations. The core component in a travelling-wave thermoacoustic engine is its regenerator where the process of energy conversion is mainly realized. This paper introduces a strategy for the design of the regenerator for applications in typical light- A nd heavy-duty vehicles. Starting from 1-D linear thermoacoustic theory, the nonlinear effects (given by the high amplitude oscillations) are modelled as acoustic resistances and introduced into the basic linear equations to estimate the nonlinear dissipations in the regenerator. Then, a few dimensionless parameters are derived by normalizing these thermoacoustic equations. This yields a good overview of how different design parameters such as the geometrical dimensions, operating temperature, and thermal boundary conditions influence the performance of the regenerator. For the application of automotive waste heat recovery, the thermal properties of the actual exhaust gas are accepted to be the boundary condition for the heat matching. The results obtained in the current work show that the optimum designs for the regenerators in travelling-wave thermoacoustic engines aimed at light- A nd heavy-duty applications widely differ due to the different thermal properties of their exhaust gas. Finally, two possible optimal designs of the regenerators in travelling-wave thermoacoustic engines for the typical light- A nd heavy-duty applications are presented. The designs are based on heat matching between the required heat by the regenerators and the available heat from the exhaust gases., QC 20200714

Renewable fuels have an important role to create sustainable energy systems. In this paper the focus is on biodiesel, which is produced from vegetable oils or animal fats. Today biodiesel is mostly used as a drop-in fuel, mixed into conventional diesel fuels to reduce their environmental impact. Low quality drop-in fuel can lead to deposits throughout the fuel systems of heavy duty vehicles. In a previous study fuel filters from the field were collected and analyzed with the objective to determine the main components responsible for fuel filter plugging. The identified compounds were constituents of soft particles. In the current study, the focus was on metal carboxylates since these have been found to be one of the components of the soft particles and associated with other engine malfunctions as well. Hence the measurement of metal carboxylates in the fuel is important for future studies regarding the fuel's effect on engines. The first aim of this study was to create synthetic soft particles from biodiesel. Accelerated aging of fuels with different contaminations such as engine oil and calcium oxide were used to create the synthetic soft particles. The precipitates were collected and analyzed with different techniques such as FTIR and GC-MS, to identify the main components which were then compared with the results of the previous study. Following this, specific attention was given to calcium methyl azelate as it was shown to be found in field fuel filters. A method using GC-MS was developed to be able to estimate the amount of soft particles by measuring calcium methyl azelate. The specified method proved to be adequate for future studies to evaluate the filtration efficiency of different filter materials against soft particles., QC 20200713

Aerospace panels are commonly restrained on complex inspection fixture jigs during the measurement process. Forces used to restrain the parts are also monitored as mandated by thier functional requirements. Given the difficulties in measuring these types of parts, this paper reviews the available fixtureless inspection methods with a focus on the challenges of their implementation, and their aptitude to be used to estimate the profile and the necessary restraining forces of an aerospace panel. To perform this investigation, finite element analysis is used to predict the constrained shape of four (4) simulated free-state aerospace panels, with two different type of boundary conditions, in five scenarios. From those analyses, the importance and limits of current finite element boundary setting methods embedded in fixtureless inspection methods for nonrigid parts are highlighted.

Since the driver obtains an important feedback of vehicle dynamics and its braking capabilities depending on a brake performance change, it represents an important aspect of vehicle performance and its quality of use. Regarding modern automotive brakes, the extreme demands have been imposed on the friction couple and its tribological performance. Different sensitivity of braking torque, i.e. a disc brake performance versus the influence of the friction couple interaction, under different braking conditions (applied pressure, speed and brake interface temperature), is one of the most important the disc brake properties. That is why, control of braking performance in the sense of providing stable braking performance during a braking cycle and their dynamic adaptation to the driver demands and/or demands imposed by ABS/ESC, are very important. Investigation presented in this paper contributes to the efforts in the direction of intelligent dynamic control of automotive braking systems performance. The dynamic model has been developed in the paper in order to provide dynamic prediction and control of the disc brake performance during a braking cycle. This model provided stabilization of the brake performance and their maximization versus the brake pedal travel, selected by a driver, and influence of the current values of initial speed, the brake activation pressure, and the brake interface temperature.

The use of innovative power sources in future cars has long-ranging implications on vehicle safety. We studied these implications in the context of the guidance on software tool qualification in the then current ISO 26262 draft, when building an urban concept vehicle to participate in the 2011 Shell Eco-Marathon. While the guidance on tool qualification is detailed, the guidance in regard to tools integrated into tool chains is limited. It only points out that the environment that tools execute in needs to be taken into consideration. In this paper we clarify the implications of tool chains on tool qualification in the context of ISO 26262 by focusing on answering two questions; first, are there parts of the development environment related to tool integration that are likely to fall outside of tool qualification efforts as currently defined by ISO 26262; secondly, can we define if, and -if so- how, tool integration is affected by ensuring functional safety. We conclude by identifying two areas related to tool integration that are likely to fall outside the tool qualification efforts (data integrity and process logic) and describing how different constraints imposed by ISO 26262 in relation to tool qualification conflict when tool integration is improved (improvements aimed at supporting completeness, consistency and the safety lifecycle vs. tool qualification cost). We are able to make additional conclusions in relation to the State of the Art discussion on software tool qualification according to ISO 26262. First, reference tool chains and guidelines on which characteristics tool qualification should ensure for tool chains are needed to complement ISO 26262. Secondly, guidance on tool integration can be found in the completeness characteristic, the consistency characteristic and the ISO 26262 safety lifecycle process. Finally, qualification efforts should ideally target tool chains rather than individual tools., QC 20120927

Engine simulation based on one-dimensional gas dynamics is well suited for integration of all aspects arising in engine and power-train developments. Commonly used turbocharger performance maps in engine simulation are measured in non-pulsating flow and without taking into account the heat transfer. Since on-engine turbochargers are exposed to pulsating flow and varying heat transfer situations, the maps in the engine simulation, i.e. GT-POWER, have to be shifted and corrected which are usually done by mass and efficiency multipliers for both turbine and compressor. The multipliers change the maps and are often different for every load point. Particularly, the efficiency multiplier is different for every heat transfer situation on the turbocharger. The aim of this paper is to include the heat transfer of the turbocharger in the engine simulation and consequently to reduce the use of efficiency multiplier for both the turbine and compressor. A set of experiment has been designed and performed on a water-oil-cooled turbocharger, which was installed on a 2 liter GDI engine with variable valve timing, for different load points of the engine and different conditions of heat transfer in the turbocharger. The experiments were the base to simulate heat transfer on the turbocharger, by adding a heat sink before the turbine and a heat source after the compressor. The efficiency multiplier of the turbine cannot compensate for all heat transfer in the turbine, so it is needed to put out heat from the turbine in addition to the using of efficiency multiplier. Results of this study show that including heat transfer of turbocharger in engine simulation enables to decrease the use of turbine efficiency multiplier and eliminate the use of compressor efficiency multiplier to correctly calculate the measured gas temperatures after turbine and compressor., QS 2012, On-Engine Turbocharger Performance

The paper gives an overview of techniques used for characterization of IC-engines as acoustic sources of exhaust and intake system noise. Some recent advances are introduced and discussed. Linear frequency domain prediction codes are frequently used for calculation of low frequency sound transmission in and sound radiation from IC-engine exhaust and intake systems, even though nonlinear time domain models are also developing fast. To calculate insertion loss of mufflers or the level of radiated sound information about the engine as an acoustic source is needed. The source model used in the low frequency plane wave range is often the linear time invariant one-port model. The acoustic source data is obtained from experimental tests or from 1-D CFD codes describing the engine gas exchange process. Multi-load methods and especially the two-load method are most commonly used to extract the source data. The IC-engine is a high level acoustic source and in most cases not completely linear. It is therefore of interest to have models taking weak non-linearity into account while still maintaining a simple method for interfacing the source model with a linear frequency domain model for the attached exhaust or intake system. Some years ago a model which can consider weakly non-linear sources was presented, which gave an improvement over the traditional two-load technique for determining source data from experiments. It is however fairly complicated to implement and has not been used a lot. In this paper an alternative technique based on so called polyharmonic distortion modeling, used for nonlinear characterization of microwave systems is introduced and tested. Comparisons are made with the results from linear source models and the previously published weakly nonlinear source model., Conference code: 127623; Export Date: 24 October 2017; Conference Paper; Correspondence Address: Boden, H.; KTHSweden; email: hansbod@kth.se. QC 20171030