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Training / Education

Photogrammetry and Analysis of Digital Media

2019-06-26
Photographs and video recordings of vehicle crashes and accident sites are more prevalent than ever, with dash mounted cameras, surveillance footage, and personal cell phones now ubiquitous. The information contained in these pictures and video provide critical information to understanding how crashes occurred, and in analyzing physical evidence. This course teaches the theory and techniques for getting the most out of digital media, including correctly processing raw video and photographs, correcting for lens distortion, and using photogrammetric techniques to convert the information in digital media to usable scaled three-dimensional data.
Technical Paper

Comparison of Measurement Methods for Evaluating Displacement of Commercial Vehicle Seats

2019-06-05
2019-01-1481
Vehicle seats and seat suspension have been evolving ever since the introduction of seats with built-in, integral suspensions. Measuring the relative displacements of the seat suspension may help better understand the magnitude and frequency of displacements the seat suspension and ultimately the occupant is exposed to. These displacement measurements may complement acceleration measurements and may provide additional information to help improve vehicle seat design. Displacement can be measured directly with lasers and potentiometers, but it would be less complicated if accelerometers, already being used to measure and characterize the vehicle and vehicle seat vibration, could be used to measure the displacement. Accelerometers can produce relatively accurate, correlated displacement results from well behaved, controlled, sinusoidal cyclical vibrations, but their utility for measuring real-world random vibration needs further evaluation and characterization.
Technical Paper

A Non-Contact Technique for Vibration Measurement of Automotive Structures

2019-06-05
2019-01-1503
The automotive and aerospace industries are increasingly using the light-weight material to improve the vehicle performance. However, using light-weight material can increase the airborne and structure-borne noise. A special attention needs to be paid in designing the structures and measuring their dynamics. Conventionally, the structure is excited using an impulse hammer or a mechanical shaker and the response is measured using uniaxial or multi-axial accelerometers to obtain the dynamics of the structure. However, using contact-based transducers can mass load the structure and provide data at a few discrete points. Hence, obtaining the true dynamics of the structure conventionally can be challenging. Thus, researchers and test engineers seek for non-contact measurement techniques that do not induce mass loading effects and provide full field response.
Technical Paper

Performance of Additive Manufactured Stacks in a Small Scale Thermoacoustic Heat Engine

2019-06-05
2019-01-1534
Standing wave thermoacoustic engines (TAEs) rely on the presence of a porous component, the "stack", where a temperature gradient is established and quasi-adiabatic heat exchanges occur between the gas in standing waves and the solid walls. The geometry and the heat conduction properties of the stack have a tremendous impact on the efficiency of the thermal-to-acoustic power conversion. Three different stacks, provided with different internal geometries, have been produced by using Selective Laser Melting (SLM), an additive manufacturing (AM) technique designed to use high power-density laser to melt and fuse metallic powders together. The three stacks are provided with parallel plates, with longitudinal pin array and with oblique pin array, respectively.
Technical Paper

Driveline NVH integration of A NA truck program

2019-06-05
2019-01-1559
In current automotive industry, it is well known that the driveline subsystem and components are normally from different automotive suppliers for OEMs. In order to ensure proper system integration and successful development of driveline system NVH performances, collaboration efforts between OEMs and suppliers are very demanding and important. In this paper, a process is presented to achieve successfulness in developing and optimizing vehicle integration through effective teamwork between a driveline supplier and a major OEM. The development process includes multiple critical steps. They include target development and roll down, targets being specific and measurable, comprehension of interactions of driveline and vehicle dynamics, accurate definition of sensitivity, proper deployment of modal mapping strategy, which requires open data sharing; and system dynamics and optimization.
Training / Education

LIDAR and Infrared Cameras for ADAS and Autonomous Sensing

2019-04-10
This two-day seminar examines ADAS and autonomous vehicle technologies that have disrupted the traditional automotive industry with their challenges and potential to increase safety while attempting to optimize the cost of car ownership. LIDAR and Infrared camera sensing are seeing a rapid growth and adoption in the industry. However, the sensor requirements and system architecture options continue to evolve almost every six months. This course will provide the foundation to build on for these two technologies in automotive applications. It will include a demonstration model for LIDAR and Infrared camera.
Technical Paper

Calibration and Stitching Methods of the Around View Monitor System of Articulated Multi-Carriage Road Vehicle for Intelligent Transportation

2019-04-02
2019-01-0873
The Around View Monitor (AVM) system of the long-body road vehicle with multiple articulated carriages usually suffers from the incomplete distortion correction of fisheye cameras on the side of the coach and the irregular image stitching area caused by the change of relative position of the cameras on different carriages while the vehicle is in motion. In response to these problems, a set of calibration and stitching methods of AVM are proposed. When the system is in the calibration mode, first a two-step optimization method is adopted to solve the polynomial radial distortion-based fisheye camera model. Then, a robust corner detection technique is proposed to extract all the chessboard corners and square vertexes in the system calibration scene. With the calibrated camera model and geometric information of the mounted system, the initial look-up table from the fisheye images to a top view of the vehicle is extrapolated.
Technical Paper

Optical experiments on strong knocking combustion in rapid compression machines with different fuels

2019-04-02
2019-01-1142
Knocking combustion has become the greatest bottleneck of internal combustion engines with advanced combustion technologies for pursuing thermal efficiency limits. Because of the complexities of combustion conditions, the mechanism for strong knocking combustion in engines under different combustion modes is still not fully understood. In this study, synchronization measurement through simultaneous pressure acquisition and high-speed direct photography was performed, and strong knocking combustion for premixed iso-octane/air mixture was studied in a high-strength optical rapid compression machine with flat piston design. First, strong knocking phenomena under both spark-ignition and compression-ignition conditions are identified through varying initial thermodynamic conditions.
Technical Paper

A Stochastic Physical Simulation Framework to Quantify the Effect of Rainfall on Automotive Lidar

2019-04-02
2019-01-0134
The performance of environment perceiving sensors such as e.g. lidar, radar, camera and ultrasonic sensors is safety critical for automated driving vehicles. Therefore, one has to assess the sensors’ performance to assure the automated driving system’s safety. The performance of these sensors is however to some degree sensitive towards adverse weather conditions. A challenge is to quantify the effect of adverse weather conditions on the sensor’s performance early in the development of an automated driving system. This challenge is addressed in this work for lidar sensors. The lidar equation was previously employed in this context to derive estimates of a lidar’s maximum range in different weather conditions. In this work, we present a stochastic simulation framework based on a probabilistic extension of the lidar equation, to quantify the effect of adverse rainfall conditions on a lidar’s raw detection performance.
Technical Paper

Effect of Injection Pressure on Nozzle Internal Flow and Jet Breakup under Sub-Cooled and Flash Boiling Test Conditions

2019-04-02
2019-01-0286
Injection pressure plays a vital role in spray break-up and atomization. High spray injection pressure is usually adopted to optimize the spray atomization in gasoline direct injection fuel system. However, higher injection pressure also leads to engine emission problem related to wall wetting. To solve this problem, researchers are trying to use flash boiling method to control the spray atomization process under lower injection test conditions. However, the effect of injection pressure on the spray atomization under flash boiling test condition has not been adequately investigated yet. In this study, quantitative study of internal flow and near nozzle spray breakup were carried out based on a two-dimensional transparent nozzle via microscopic imaging and phase Doppler interferometery. N-hexane was chosen as test fluid with different injection pressure conditions. Fuel temperature varied from 112°C to 148°C, which covered a wide range of superheated conditions.
Technical Paper

Nozzle Flow Simulation of GDi for Measuring Near-Field Spray Angle and Plume Direction

2019-04-02
2019-01-0280
Experimental visualization of current gasoline direct injection (GDi) systems are even more complicated especially due to the proximity of spray plumes and the interaction between them. Computational simulations may provide additional information to understand the complex phenomena taking place during the injection process. Nozzle flow simulations with a Volume-of-Fluid (VOF) approach can be used not only to analyze the flow inside the nozzle, but also the first 2-5 mm of the spray. A methodology to obtain plume direction and spray angle from the simulations is presented. Results are compared to experimental data available in the literature. It is shown that plume direction is well captured by the model, whilst the uncertainty of the spray angle measurements does not allow to clearly validate the developed methodology.
Technical Paper

Imaging of Fuel-Film Evaporation and Combustion in a Direct-Injection Model Experiment

2019-04-02
2019-01-0293
Late-evaporating liquid fuel films within the combustion chamber are considered a major source of soot in gasoline direct-injection engines. In this study a direct-injection model experiment was developed to visualize and investigate the evaporation of fuel films and their contribution to soot formation with different diagnostic techniques. A mixture of isooctane (surrogate fuel) and toluene (fluorescent tracer) is injected by a multi-hole injector into a wind tunnel with an optically accessible test section. Air flows continuously at low speed and ambient pressure through the test section. Some of the liquid fuel impinges on the quartz-glass windows and forms fuel films. Combustion is initiated by a pair of electrodes within the fuel/air-mixture. The turbulent flame front propagates through the chamber and ignites pool fires near the fuel films, leading to locally sooting combustion.
Technical Paper

Study of Flash Boiling Spray Combustion in a Spark Ignition Direct Injection Optical Engine Using Digital Image Processing Diagnostics

2019-04-02
2019-01-0252
Flash boiling spray has been proven to be a useful method in providing finer fuel droplet and stronger evaporation in favor of creating a homogeneous fuel-air mixture. Combustion characteristics of flash boiling spray are thus valuable to be investigated systematically for aiding the development of efficient internal combustion system. An experimental study of flash boiling spray combustion in a SIDI optical engine under early injection has been conducted. The fuel, Iso-octane, was used across all tests. Three fuel spray conditions experimented in the study: normal liquid, transitional flash boiling and flare flash boiling sprays, within each case that Pa/Ps ratio was set in (>1), (0.3~1), and (<0.3) respectively. A small quartz insert on the piston enables optical access for observing combustion process; non-intrusive measurements on flame radicals has been carried out using a high-speed color camera.
Technical Paper

Geometric Description of the Soot Cake in a One-Dimensional Model of an Octo-Square Asymmetric Particulate Filter

2019-04-02
2019-01-0991
Asymmetric particulate filters (PF), where the inlet channel is wider than the outlet channel, are commonly used because of their greater ash capacity. Surprisingly, very few models for asymmetric PFs have been published. This paper considers how to model the soot cake in octo-square asymmetric PFs. Some previous studies have neglected the octahedral shape of the inlet channel and instead erroneously assumed that the inlet channels were square. As the correct approach for modelling the soot cake is not obvious, three options are considered. The calculation of soot-loaded channel perimeter and hydraulic diameter (which are important for heat and mass transfer), soot thickness and backpressure as a function of soot loading are given for each geometry. In option 1, the shape of the soot-loaded channel is assumed to be geometrically similar to the soot-free channel.
Technical Paper

Reconstruction of 3D Accident Sites Using USGS LiDAR, Aerial Images, and Photogrammetry

2019-04-02
2019-01-0423
The accident reconstruction community has previously relied upon photographs and site visits to recreate a scene. This method is difficult in instances where the site has changed or is not accessible. In 2017 the United States Geological Survey (USGS) released historical 3D point clouds (LiDAR) allowing for access to digital 3D data without visiting the site. This offers many unique benefits to the reconstruction community including: safety, budget, time, and historical preservation. This paper presents a methodology for collecting this data and using it in conjunction with aerial imagery, and camera matching photogrammetry to create 3D computer models of the scene without a site visit.
Technical Paper

Surface Mapping in 3D Coordinate Metrology for Automotive Industry

2019-04-02
2019-01-1270
Surface mapping for freeform using CNC-CMM plays an important role in advanced coordinate industries. CNC-CMM machine can assess the parts specification, which has a significant impact on design, manufacturing, inspection and quality control processes. This article, presented four important issues to give a comprehensive view of the progress in this area. Eventually, the aim of this work is to give an overview of 3D plot mapping using freeform artifact utilizing computer aided inspection technique in the area of industrial dimensional metrology. This work happens as a new guide to cover and develop the lack of standard artifact for evaluation geometrical surface features in 3D coordinate metrology to optimize the precision, accuracy and verification time especially for automotive industry.
Technical Paper

High Resolution LiDAR Based on Single Chip SPAD Array

2019-04-02
2019-01-0119
It is important that Advanced Driver Assistance Systems (ADAS) and Automated Driving Systems (AD) detect on-road objects, road vehicles and pedestrians. The typical detection devices mounted on ADAS and AD include a camera, a millimeter-wave radar and a Light Detection And Ranging (LiDAR). Since LiDAR can obtain accurate distance and fine spatial resolution due to its short wavelength, it is expected that small objects such as a tire can be detected. However, the conventional LiDAR is equipped with multiple light transmitters and light receivers such as avalanche photo diodes. This causes LiDAR system to be expensive and large in size. Aiming to reduce the cost and size of LiDAR, we employed Single-Photon Avalanche Diode (SPAD) which can be fabricated by CMOS process and easily arrayed. We also developed “Single Chip SPAD Array“ in which the two-dimensional array of SPAD and a signal processing block of range calculation were integrated into a single chip.
Technical Paper

A Study on Improvement of Optical/Electrical Properties of Indium-Tin-Oxide Thin Films Prepared by Sol-Gel Process

2019-04-02
2019-01-0187
Ar plasma treatment was carried out to reduce the sheet resistance of indium tin oxide (ITO) thin films. To verify how the concentration of oxygen vacancies in the film increased with the Ar plasma treatment time, cumulative and continuous plasma treatments were conducted. In addition, to improve the transmittance and reduced the sheet resistance the PDMS layer was as a stamp on the surface of ITO. The oxidation of the PDMS stamp appears to be a key factor to improve the characteristics of ITO thin film. Furthermore, an indium-tin-oxide (ITO) thin film with approximately 50 nm thickness was successfully synthesized on glass substrates by using a fully aqueous sol-gel process. The annealing temperature and argon plasma treatment time appear to be key factors in reducing resistivity and increasing the transmittance of the thin film.
Technical Paper

Measuring the Displacement of a Vehicle Body with an Optical Measuring System (Motion Capture)

2019-04-02
2019-01-0393
The 3D measurement of a body displacement on a moving vehicle is a quite challenging process. Well-known displacement measuring device such as a dial gauge and strain gauge can measure the displacement in only limited areas. An accelerometer also can estimate body motion but it has an accumulated error and a bias issue for an acquisition of displacements. However, an optical measuring (Motion Capture) method which uses markers and multiple cameras can read 3D coordinates directly and carry out those measurements well. In this paper, first, we determined how to extract a body displacement from global motion. Then we suggested a combining measurement methodology which uses a motion capture and an accelerometer simultaneously. Though it has failed to compensate each result and exact displacement, we showed an accuracy comparison between a motion capture and an accelerometer to measure a displacement along this process.
Technical Paper

ASIL-Decomposition and Related DFA for Autonomous Driving Systems

2019-04-02
2019-01-0135
According to ISO 26262, ASIL decomposition is the breakdown of a top level safety requirement derived from safety goal into redundant safety requirements with sufficient independence to achieve the safety goal independently. The usage of decomposition enables the opportunity to reduce the ASIL rating of the decomposed safety requirements of a safety goal. To apply decomposition, the decomposed safety requirements should be allocated to sufficiently independent architectural elements. If the redundant/decomposed safety requirements cannot be allocated to sufficiently independent architectural elements, then these redundant safety requirements inherit the initial ASIL of the safety goal. ASIL decomposition can be applied to the functional, technical, hardware or software safety requirements of the item.
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