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Technical Paper

Determination of Interior NVH Levels from Tire/Wheel Variations using a Monte Carlo Process

Variability in design (e.g. tolerance), material, manufacturing, or other sources of variation causes significant variation in vehicle noise, vibration and harshness (NVH) response. This leads to a higher percentage of produced vehicles with higher levels of NVH leading to higher number of warranty claims and loss of customer satisfaction, which are proven costly to the original equipment manufacturers (OEM). Measures must be taken to insure less warranty claims and higher levels of customer satisfaction. As a result, original equipment manufacturers have implemented design for variation in the design process to secure an acceptable (or within specification) response. We will focus on some aspects of design variations in a tire/wheel assembly that should be considered in the design process. In particular, certain materials (e.g. rubber) are known to have variation in stiffness that is either unavoidable or proven costly if tighter control is desired.
Technical Paper

Sensitivity of Accident Reconstruction Calculations

A number of simplistic formulae, based on particle dynamics, energy, and momentum methods are routinely employed by accident reconstructionists to calculate vehicle speeds immediately prior to impact. It is almost always the case that scene evidence and other information regarding important variables involved in such equations must either be estimated or can be measured only in an approximate way. ...Example problems illustrate the difficulties faced by accident reconstructionists as they grapple with incomplete and/or estimated values for important variables, and with the inherent sensitivity of some of the calculations to seemingly small variations in variable magnitudes.
Journal Article

Automatic Transmission Gear Ratio Optimization and Monte Carlo Simulation of Fuel Consumption with Parasitic Loss Uncertainty

An enterprise approach for vehicle fleet balancing of fuel consumption objectives based upon selection of automatic transmission gearing strategy is presented. Monte Carlo simulations for the influence of parasitic loss uncertainty for the automatic transmissions selected from the generalized DOE were conducted to determine the range of fuel consumption that might be realized in production. ...Automatic transmission gearing parameter selection was unaffected by the variation introduced by the Monte Carlo simulations, but did show fuel consumption performance to vary upwards of 9 g CO2/km depending on applications and to have a direct impact on powertrain operating parameters.
Journal Article

Vehicle Design for Robust Driveline NVH Due to Imbalance and Runout Using a Monte Carlo Process

Variation in vehicle noise, vibration and harshness (NVH) response can be caused by variability in design (e.g. tolerance), material, manufacturing, or other sources of variation. Such variation in the vehicle response causes a higher percentage of produced vehicles with higher levels (out of specifications) of NVH leading to higher number of warranty claims and loss of customer satisfaction, which are proven costly. Measures must be taken to ensure less warranty claims and higher levels of customer satisfaction. As a result, original equipment manufacturers have implemented design for variation in the design process to secure an acceptable (or within specification) response. This paper focuses on aspects of design variations that should be considered in the design process of drivelines. Variations due to imbalance and runout in rotating components can be unavoidable or costly to control.
Technical Paper

Particulate Matter Formation Dynamics as Investigated by Ultra-Accelerated Quantum Chemical Molecular Dynamics Coupled with Canonical Monte Carlo Method

Suppression or reduction of soot emissions is an important goal in the development of automotive engines for environmental and human health purposes. A better understanding at the molecular level of the formation process of soot particles resulting from collision and aggregation of smaller particles made of Polycyclic Aromatic Hydrocarbon (PAH) is needed. In addition to experiments, computational methods are efficient and valuable tools for this purpose. As a first step in our detailed computational chemistry study, we applied Ultra-Accelerated Molecular Dynamics (UAQCMD) and Canonical Monte-Carlo (CMC) methods to investigate the nucleation process. The UA-QCMD can calculate chemical reaction dynamics 107 times faster than conventional first principle molecular dynamics methods, while CMC can calculate equilibrium properties at various temperatures, pressures, and chemical compositions.
Journal Article

A Monte Carlo Based Turbulent Flame Propagation Model for Predictive SI In-Cylinder Engine Simulations Employing Detailed Chemistry for Accurate Knock Prediction

The flame development was calculated from the turbulent flame speed under the assumption of a spherical flame. A Monte Carlo geometry calculation was applied to cater for arbitrary cylinder geometries and spark plug positions, modelling the geometrical properties of the flame with high precision. ...In later stages of the project, a polygon based description of the flame surface was used, to achieve faster computational times than those of the Monte Carlo model.
Technical Paper

Videogrammetry in Vehicle Crash Reconstruction with a Moving Video Camera

Suppose video footage from a dash camera mounted to one of the vehicles involved in the accident is provided for an accident reconstruction but EDR data is unavailable for either of the vehicles involved. ...In an accident reconstruction, vehicle speeds and positions are always of interest. When provided with scene photographs or fixed-location video surveillance footage of the crash itself, close-range photogrammetry methods can be useful in locating physical evidence and determining vehicle speeds and locations. ...To address the increasing prevalence of dash cams and other in-vehicle video and the value in using such video in vehicle crash reconstruction, this paper describes techniques for determining the position and speed of a moving object from digital video taken from a moving vehicle.
Technical Paper

The Analysis of Accident Data Recorder (ADR) Data in Formula 1

The data is used to compute deceleration rates for use in the FIA's Circuit and Safety Analysis System (CSAS) for the assessment of circuit safety features, assess barrier and car impact performance, and provide data for accident reconstruction and modelling. A Severity Index Coefficient (SIC) has been developed to enable impacts to be assessed quickly for their potential to cause head injuries, in order to rate them according to their need for fuller analysis. ...The FIA has fitted Accident Data Recorders (ADR) to all Formula1 cars since 1997, and will also fit them to Formula 3000 cars from 2000.
Technical Paper

Application of Signal Reconstruction to On-Road Emissions Testing

Data was taken from these analyzers and passed, off-line, through the reconstruction filter. In addition, part of the Federal Urban Driving Schedule was simulated on the chassis dynamometer and emissions data collected from the test vehicle.
Technical Paper

Input Force Reconstruction for Vehicle Durability

In vehicle durability, the determination of accurate input forces can lead to a greater reliance on numerical simulations using analytical models and reduce the need for more expensive and time consuming experimental testing. Traditionally, the input forces are directly measured using load cells. However, in many instances, the direct measurement of force by load cells is either impossible or inaccurate, such as in the case of vehicle body and engine mount loads. To improve the techniques on automobile durability analysis, there is a need to be able to construct the input forces indirectly; i.e., to calculate the input forces by measuring the subsequent structural responses. In essence, the instrumented structure becomes its own load cell. The current study attempts to calculate the body mount loads of a light truck vehicle using the proposed technique. A finite element model of a vehicle body structure is used to locate the areas of load sensitivity.
Technical Paper

Misfire Detection and Cylinder Pressure Reconstruction for SI Engines

Many researchers have studied and developed methods for on-board engine combustion misfire detection in production vehicles. Misfiring can damage the catalytic converter within a short time and can lead to increased emission levels. For that reason, the on-board detection of engine misfire is one requirement of the On Board Diagnosis II (OBDII) Regulation and a recent interest for many researchers. One object in this paper is to propose a misfire detection method for multi-cylinder SI engines. The detection is achieved by examining the estimated cylinder pressures and combustion heat release rates in engine cylinders. The Sliding Observer methodology is applied in these estimations. This detection method provides a reliable and low-cost way to diagnose engine misfires. The other object of the paper is to eliminate large estimation errors due to system unobservability and reconstruct cylinder pressures.
Technical Paper

Signal Reconstruction Applied to a Fast Response Flame Ionisation Detector

The Fast-response Flame Ionisation Detector is used to measure levels of un-burnt hydrocarbons in the cylinder and exhaust of engines. Its fast response allows uHC emission processes to be resolved within an engine cycle. This paper describes a method for obtaining even greater detail by post-processing the output of the device using a Finite-Impulse Response (FIR) digital filter. The specification of the filter can be obtained by understanding the flow regimes within the sampling system. Examples from in-cylinder and exhaust sampling are presented with suggestions for implementation and further improvement.
Technical Paper

Reconstruction of Pressure Signals on Structure-borne Sound for Knock Investigation

Knocking combustions decrease the efficiency of an SI engine and can cause damages in combustion chambers. The in-cylinder pressure signal provides an insight into the combustions. Due to cost and installation reasons, vibration signals are used for knock analysis in conventional engines; however, vibration signal analysis is less effective than pressure signal analysis. The aim of this paper is to approximate the pressure signal, which is more suitable for knock investigation, from structure-borne sound. Therefore, new models for pressure and vibration signals, related to each other, are presented. These models consist of constructional specific signal components and combustion specific random parameters. The signal components need to be determined only once for an engine by using ordinary mathematical tools. A least-squares method, applied on vibration signals, leads to estimates of the random parameters.
Technical Paper

Performance of a Non-Lacerative Windshield in Case of Accident and Under Environmental Conditions

The four-layer laminated Securiflex windshield has been tested in simulated collisions at the Wayne State University up to 40 mph Barrier Equivalent Velocities, to demonstrate that it causes no laceration. has been exposed to usual and extreme environmental conditions to demonstrate its serviceability in field use. The new windshield consists of a conventional laminated construction (glass/high penetration resistant interlayer/glass) combined with a 0.5 mm innerlayer of plastic. Glass is used on the outer surface of the windshield to withstand the abrasion and scratching of sand, windshield wipers and cleaning. The laminated construction prevents penetration and provides a pocket or cushion action to decelerate the head without injury. The innerlayer is made of a special plastic film which protects the face of the occupants against laceration and eye injury during head impact.