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Enhancement of Occupant Ride Comfort by GA Optimized PID Control Active Suspension System

Anna University-Arivazhagan Anandan, Arunachalam K
  • Technical Paper
  • 2020-01-1532
To be published on 2020-06-03 by SAE International in United States
The main objective of this work is to enhance the occupant ride comfort. Ride comfort is quantified in terms of measuring distinct accelerations like sprung mass, seat and occupant head. For this theoretical evaluation, a 7- degrees of freedom (DOF) human-vehicle-road model was established and the system investigation was limited to vertical motion. Besides, this work also focused to guarantee other vehicle performance indices like suspension working space and tire deflection. A proportional-integral-derivative (PID) controller was introduced in the vehicle model and optimized with the aid of the genetic algorithm (GA). Actuator dynamics is incorporated into the system. The objective function for PID optimization was carried out using root mean square error (RMSE) concept. The severity of various suspension indices and biomechanics responses of the developed model under proposed approach were theoretically analyzed using various road profiles and compared with conventional passive system. Furthermore, this work discussed the seat to head transmissibility ratio (STH) response to examine the severity of whole-body vibration (WBV). Subsequently, the respective performance measures were statistically analyzed using root mean square…
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Challenges in Vibroacoustic Vehicle Body Simulation Including Uncertainties

BMW AG-Marinus Luegmair
Technical University of Munich / BMW AG-Johannes D. Schmid
  • Technical Paper
  • 2020-01-1571
To be published on 2020-06-03 by SAE International in United States
For many years, the model quality and frequency range of NVH simulation with Finite Element (FE) models have been increased and led to a better vehicle quality. Nowadays, model range and quality are on such a high fidelity and there is often no further improvement, even with extreme modelling and computation effort. So in order to improve the quality of predictions, the next step is to take uncertainties into account. With this approach there are many challenges on the way to valid and useful simulation models and they can be divided into three areas: the input uncertainties, the propagation of uncertainties through the FE model and finally the statistical output quantities. Each of them must be investigated to choose sufficient methods for a valid and fast prediction of vehicle body vibroacoustics. With a discrimination of different types of uncertainties it can be shown that the dimensionality of the corresponding random space is tremendously high. Therefore, a substantial reduction of the dimensionality is crucial. Next step is to choose a proper method to model uncertainties and…
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Using Statistical Energy Analysis to Optimize Sound Package for Realistic Load Cases

Audi AG-Christian März, Matej Glavac
ESI GmbH-Arnaud Caillet, Oussama Fatmi
  • Technical Paper
  • 2020-01-1525
To be published on 2020-06-03 by SAE International in United States
The statistical energy analysis (SEA) is widely used to support the development of the sound package of cars. This paper will present a model prepared to investigate the sound package of the new Audi A3 and its correlation against measurements. Special care was given during the creation of the model on the representation of the structure to able the analysis of structure borne energy flow on top of the classical airborne analysis usually done with SEA. The sound package is also detailed in the model to allow further optimization and analysis of its performance. Two real life load cases will be presented to validate the model with measurements. First, the dominating powertrain and second, a case with dominating rolling noise. An analysis of the contribution of the different source components and a way to diagnose the weak paths of the vehicle will be presented. The focus of this investigation is the application of optimally adjusted treatment.
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Extended Solution of a Trimmed Vehicle Finite Element Model in the Mid-Frequency Range

Audi Hungaria Zrt.-Antoine Guellec, Daniel Feszty
Hexagon | Free Field Technologies-Markus Brandstetter, Jonathan Jacqmot
  • Technical Paper
  • 2020-01-1549
To be published on 2020-06-03 by SAE International in United States
The acoustic trim components play an essential role in Noise, Vibration and Harshness (NVH) behavior by reducing both the structure borne and airborne noise transmission while participating to the absorption inside the car and the damping of the structure. Over the past years, the interest for numerical solutions to predict the noise including trim effects in mid frequency range has grown, leading to the development of dedicated CAE tools. Finite Element (FE) models are an established method to analyze NVH problems. FE analysis is a robust and versatile approach that can be used for a large number of applications, like noise prediction inside and outside the vehicle due to different sources or pass-by noise simulation. Typically, results feature high quality correlations. However, future challenges, such as electric motorized vehicles, with changes of the motor noise spectrum, will require an extension of the existing approaches. In this paper, the vibro-acoustic frequency response of an existing MSC Nastran FE model is extended using the Actran Statistical Energy Analysis (SEA) approach, Virtual SEA. In Virtual SEA, the necessary…
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Appropriate Damping Loss Factor of Vehicle Interior Cavity For Valid Application of Statistical Energy Analysis

Hyundai Motor Company-Ki-Sang Chae, Byung Young Oh
  • Technical Paper
  • 2020-01-1524
To be published on 2020-06-03 by SAE International in United States
By using a method of a previous study (SAE 2014-01-2081), sound transmission loss (STL) of vehicle panel structure could be calculated with an FEM model. The FEM model is consisting of the body in white, a hemispehere-shaped exterior cavity, and the interior cavity. The exterior cavity is excited and Statistical Energy Analysis (SEA) principle is applied for the calculation of STL of vehicle panel structure. It is known that SEA is a rapid and simple methodology for analyzing the complex vibroacoustic system. However, SEA principle is not always valid and one has to be careful about the physical conditions at which SEA principle is acceptable. In this study, the appropriate damping loss factor of the vehicle interior cavity is studied in the viewpoint of the modal overlap factor of the cavity and the decay per mean free path (DMFP) of the cavity. It is found that DMFP is appropriate between 0.5 ~ 1 dB for applying SEA principle. DMFPs of several vehicles' interior compartments are observed between 1 dB ~2.5 dB, and which means that…
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Ramped Versus Square Injection Rate Experiments in a Heavy-Duty Diesel Engine

DAF Trucks NV-Bogdan Albrecht
Delphi Technologies-Tony Simpson
  • Technical Paper
  • 2020-01-0300
To be published on 2020-04-14 by SAE International in United States
CO2 regulations on heavy-duty transport are introduced in essentially all markets within the next decade, in most cases in several phases of increasing stringency. To cope with these mandates, developers of engines and related equipment are aiming to break new ground in the fields of combustion, fuel and hardware technologies. In this work, a novel diesel fuel injector, Delphi’s DFI7, is utilized to experimentally investigate and compare the performance of ramped injection rates versus traditional square fueling profiles. The aim is specifically to shift the efficiency and NOx tradeoff to a more favorable position. The design of experiments methodology is used in the tests, along with statistical techniques to analyze the data. Results show that ramped and square rates - after optimization of fueling parameters - produce comparable gross indicated efficiencies. Tests were carried out at 1200 and 1425 rpm; for the latter engine speed peak efficiency was attained at considerably lower NOx levels by applying a ramped injection rate. Particulate matter emissions, on the other hand, are generally lower with the use of square…
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The Effect of an Active Thermal Coating on Efficiency and Emissions from a High Speed Direct Injection Diesel Engine

Thistle Dubh Ltd.-Robert Gilchrist
University of Oxford-Nick Papaioannou, Felix Leach, Martin Davy
  • Technical Paper
  • 2020-01-0807
To be published on 2020-04-14 by SAE International in United States
This study looked into the application of active thermal coatings on the surfaces of the combustion chamber as a method of improving the thermal efficiency of internal combustion engines. The active thermal coating was applied to a production aluminium piston and its performance was compared against a reference aluminium piston on a single-cylinder diesel engine. The two pistons were tested over a wide range of speed/load conditions and the effects of EGR and combustion phasing on engine performance and tailpipe emissions were also investigated. A detailed energy balance approach was employed to study the thermal behaviour of the active thermal coating. In general, improvements in indicated specific fuel consumption were not statistically significant for the coated piston over the whole test matrix. Mean exhaust temperature showed a marginal increase with the coated piston of up to 6 °C. However, the normalised exhaust enthalpy showed a reduction (apart from the higher speed/load conditions when no EGR was applied). Energy transfer to the coolant was reduced by as much as 1.5 percentage points, in agreement with the…
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Accelerometer-Based Estimation of Combustion Features for Engine Feedback Control of Compression-Ignition Direct-Injection Engines

Army Research Laboratory-Kenneth Kim
Dept of Army-Chol-Bum Kweon
  • Technical Paper
  • 2020-01-1147
To be published on 2020-04-14 by SAE International in United States
An experimental investigation of non-intrusive combustion sensing was performed using a tri-axial accelerometer mounted to the engine block of a small-bore high-speed 4-cylinder compression-ignition direct-injection (CIDI) engine. This study investigates potential techniques to extract combustion features from accelerometer signals to be used for cycle-to-cycle engine control. Selection of accelerometer location and vibration axis were performed by analyzing vibration signals for three different locations along the block for all three of the accelerometer axes. A magnitude squared coherence (MSC) statistical analysis was used to select the best location and axis. Based on previous work from the literature, the vibration signal filtering was optimized, and the filtered vibration signals were analyzed. It was found that the vibration signals correlate well with the second derivative of pressure during the initial stages of combustion. Two combustion parameters were the focus of this investigation, start of combustion (SOC) and crank-angle of fifty-percent heat release (CA50). The results show that, for a wide range of engine conditions, SOC can be obtained solely from the first derivative of the vibration signal with…
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Impact of EV Charging on Power System with High Penetration of EVs: Simulation and Quantitative Analysis Based on Real World Usage Data

Nissan Motor Co., Ltd.-Kenta Suzuki, Yuki Kobayashi, Kensuke Murai, Keigo Ikezoe
  • Technical Paper
  • 2020-01-0531
To be published on 2020-04-14 by SAE International in United States
The adoption of electric vehicles (EVs) has been announced worldwide with the aim of reducing CO2 emissions. However, a significant increase in electricity demand by EVs might impact the stable operation of the existing power grid. Meanwhile, EV charging is acceptable to most users if it is completed by the time of the next driving event. From the viewpoint of power grid operators, flexibility for shifting the timing of EV charging would be advantageous, including making effective use of renewable energy.In this work, an EV model and simulation tool were developed to make clear how the total charging demand of all EVs in use will be influenced by future EV specifications (e.g., charge power) and installation of charging infrastructure. Among the most influential factors, EV charging behavior according to use cases and regional characteristics were statistically analyzed based on the real-world usage data of over 14, 000 EVs and incorporated in the simulation tool. Using the resultant statistical model, the Monte Carlo method was applied to conduct a parameter simulation study of continuous EV usage.…
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Process-Monitoring-for-Quality — A Step Forward in the Zero Defects Vision

General Motors LLC-Carlos Escobar, Jorge Arinez
Tecnologico de Monterrey-Ruben Morales-Menendez
  • Technical Paper
  • 2020-01-1302
To be published on 2020-04-14 by SAE International in United States
More than four decades ago the concept of zero defects was coined by Phillip Crosby. At that time it was only a vision, but today with the introduction of Artificial Intelligence in manufacturing it has become attainable. Since most mature manufacturing organizations have merged traditional quality philosophies and techniques, their processes generate only a few defects per million of opportunities. Therefore, detecting these rare quality events is one of the modern intellectual challenges posed by this industry. Process Monitoring for Quality is a big data-driven quality philosophy aimed at defect detection and empirical knowledge discovery. Detection is formulated as a binary classification problem, where the right machine learning, optimization and statistics techniques are applied to develop an effective predictive system. Manufacturing-derived data sets for binary classification of quality tend to be highly/ultra unbalanced, making it very difficult for the learning algorithms to learn the minority (defective) class. In this paper, the learning and deployment paradigm of Process Monitoring for Quality is presented, a discussion of how it interacts with traditional quality philosophies to enable the…