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As vehicle emissions regulations become increasingly stringent, there is a growing need to accurately model aftertreatment systems to aid in the development of ultra-low NOx vehicles. Common solutions to this problem include the development of complex chemical models or expansive neural networks. This paper aims to present the development process of a simpler Selective Catalytic Reduction (SCR) conversion efficiency Simulink model for the purposes of modeling tail pipe NOx emission levels based on various inputs, temperature shifts and SCR locations, arrangements and/or sizes in the system. The main objective is to utilize this model to predict tail pipe NOx emissions of the EPA Federal Test Procedures for heavy-duty vehicles. The model presented within is focused exclusively on heavy-duty application compression ignition engines and their corresponding aftertreatment setups.

In order to validate the operation of advanced driver assistance systems (ADAS), tests must be performed that assess the performance of the system in response to different scenarios. Some of these systems are designed for crash-imminent situations, and safely testing them requires large stretches of controlled pavement, expensive surrogate targets, and a fully functional vehicle. As a possible more-manageable alternative to testing the full vehicle in these situations, this study sought to explore whether these systems could be isolated, and tests could be performed on a bench via a hardware-in-the-loop methodology. For camera systems, these benches are called Camera-in-the-Loop (CiL) systems and involve presenting visual stimuli to the device via an external input.

The Federal Side Impact Test Procedure prescribed by FMVSS 214, simulates a central, orthogonal intersection collision between two moving vehicles by impacting the side of the stationary test vehicle with a moving test buck in a crabbed configuration. While the pre- and post-impact speeds of the vehicles involved in an accident can not be duplicated using this method, closing speeds, vehicle damage, vehicle speed changes and vehicle accelerations can be duplicated. These are the important parameters for the examination of vehicle restraint system performance and the prediction of occupant injury. The acceptability of this method of testing is not as obvious for the reconstruction of accidents where the impact is non-central, or the angle of impact is not orthogonal. This paper will examine the use of crash testing with a single moving vehicle to simulate oblique or non-central collisions between two moving vehicles.

In this paper, a series of design, development, and implementation details for testing and evaluation of Lane Departure Warning and Prevention systems are being discussed. The approach taken to generate a set of repeatable and relevant test scenarios and to formulate the test procedures to ensure the fidelity of the collected data includes initial statistical analysis of applicable statistics; growth and probabilistic pruning of a test matrix; simulation studies to support procedure design; and vehicle instrumentation for data collection. The success of this comprehensive approach strongly suggests that the steps illustrated in this paper can serve as guidelines towards a more general class of vehicular safety and advanced driver assistance systems evaluation.

This study examines the performance of rear-facing child restraint systems (RF CRS) in moderate severity rear impact sled tests. The study also investigates the effects of RF CRS features on CRS kinematics and anthropomorphic test device (ATD) injury metrics in this scenario. Twelve tests were conducted at a moderate severity rear impact sled pulse (approximately 28.2 km/h and 18.4 g). Four models of RF CRS were tested in the rear outboard positions of a sedan seat. The CRABI 12-month-old and Hybrid III 3-year-old ATDs were instrumented with head and chest accelerometers, head angular rate sensors, six-axis upper neck load cells, and a chest linear potentiometer (3-year-old only). The effects of carry handle position, occupant size, presence of anti-rebound bar, Swedish style tethering, and lower anchor vs. seat belt installation were investigated. Data were also compared to pediatric injury assessment reference values (IARV).

Testing vision-based advanced driver assistance systems (ADAS) in a Camera-in-the-Loop (CiL) bench setup, where external visual inputs are used to stimulate the system, provides an opportunity to experiment with a wide variety of test scenarios, different types of vehicle actors, vulnerable road users, and weather conditions that may be difficult to replicate in the real world. In addition, once the CiL bench is setup and operating, experiments can be performed in less time when compared to track testing alternatives. In order to better quantify normal operating zones, track testing results were used to identify behavior corridors via a statistical methodology. After determining normal operational variability via track testing of baseline stationary surrogate vehicle and pedestrian scenarios, these operating zones were applied to screen-based testing in a CiL test setup to determine particularly challenging scenarios which might benefit from replication in a track testing environment.

Low speed autonomous shuttles emulating SAE Level L4 automated driving using human driver assisted autonomy have been operating in geo-fenced areas in several cities in the US and the rest of the world. These autonomous vehicles (AV) are operated by small to mid-sized technology companies that do not have the resources of automotive OEMs for carrying out exhaustive, comprehensive testing of their AV technology solutions before public road deployment. Due to the low speed of operation and hence not operating on roads containing highways, the base vehicles of these AV shuttles are not required to go through rigorous certification tests. The way these vehicles’ driver assisted AV technology is tested and allowed for public road deployment is continuously evolving but is not standardized and shows differences between the different states where these vehicles operate.

Experimentally derived brain response envelopes are needed to evaluate and validate existing finite element (FE) head models. Motion of the brain relative to the skull during rotational input was measured using high-speed biplane x-ray. To generate repeatable, reproducible, and scalable data, methods were developed to reduce experimental variance. An “extreme-energy” device was developed to provide a controlled input that is unaffected by specimen characteristics. Additionally, a stereotactic frame was used to deploy radiopaque markers at specific, pre-determined locations within the brain. One post-mortem human surrogate (PMHS) head specimen was subjected to repeat tests of a half-sine rotational speed pulse in the sagittal plane. The desired pulse had a peak angular speed of 40 rad/s and duration of 30 ms. Relative motion of the brain was quantified using radiopaque targets and high-speed biplane x-ray. Frontal and occipital intracranial pressure (ICP) were also measured.

A significant number of formed parts constitute the components of an automobile or aircraft. The formed blanks for the components are produced at different temperatures ranging from room temperature to 2250 degrees Fahrenheit for steel. Forming progressions convert a basic shape or geometry (a cylindrical billet, for example) of metal into a more complex shape close to the required final component geometry. The progression steps, choice of temperatures and equipment significantly impact the cost of the blank. A ‘Discriminating Cost Model’ was developed to capture the cost effectiveness of a given choice of process or equipment, and an AI (Artificial Intelligence) search algorithm implemented to quickly search through the large number of process and equipment selection options to arrive at the most cost effective choice. Two applications of this methodology to existing plant processes to significantly reduce cost and implement ‘lean’ principles of manufacturing are discussed.

A machine has been developed to measure the complete inertia matrix; mass, center of gravity (CG) location, and all moments and products of inertia. Among other things these quantities are useful in studying engine vibrations, calculation of the torque roll axis, and in the placement of engine mounts. While the machine was developed primarily for engines it can be used for other objects of similar size and weight, and even smaller objects such as tires and wheels/rims. A key feature of the device is that the object, once placed on the test table, is never reoriented during the test cycle. This reduces the testing time to an hour or less, with the setup time being a few minutes to a few hours depending on the complexity of the shape of the object. Other inertia test methods can require up to five reorientations, separate CG measurement, and up to several days for a complete test.

The capabilities of the servo press for varying the ram speed during stroke and for adjusting the stroke length are well known. Various companies installed servo presses for blanking. Some of the considerations may include increase in productivity and flexibility in adjusting the ram stroke, noise reduction and improvement of edge quality of blanked edge. The objectives of this study are to determine the effect of ram (blanking) speed upon the edge quality, and the effect of multiple step blanking using several punch motions, during one blanking stroke.

Vaporizing Foil Actuators (VFA) are based on the phenomenon of rapid vaporization of thin metallic foils and wires, caused by passage of a capacitor bank driven current on the order of 100 kA. The burst of the conductor is accompanied with a high-pressure pulse, which can be used for working metal at high strain rates. This paper focuses on the use of VFA for collision welding of dissimilar metals, in particular, aluminum and steel. Aluminum alloy 6061 sheets of 1 mm thickness were launched to velocities in excess of 650 m/s with input electrical energy of 8 kJ into 0.0762 mm thick, dog-bone shaped aluminum foil actuators. Target sheets made from dual phase steel (DP780) were impacted with the aluminum flyer sheet, and solid state impact welds were created. During mechanical testing, many samples failed outside the weld area, thereby indicating that the weld was stronger than the parent aluminum.

Sled testing procedures should reflect a rigorous level of repeatability across trials and reproducibility across testing facilities. Currently, different testing facilities use various methods to set the harness tension for child restraint system (CRS) sled tests. The objective of this study is to identify which harness tightening procedure(s) produce tensions within a reasonable target range while showing adequate reproducibility, repeatability, and ease-of-use. Five harness tightening procedures were selected: A) FMVSS 213 procedure, B) a 3-prong tension gauge, C) ECE R44/R129 procedure, D) two finger method, and E) pinch test. Two CRS models were instrumented with a tension load cell in the harness system. Seven sled room operators were recruited to perform each of the five harness tightening procedures for ten repetitions apiece on both instrumented CRS using a Hybrid III 3-year-old.

Edge fracture is a common problem when forming advanced high strength steels (AHSS). A particular case of edge fracture occurs during a collar forming/hole extrusion process, which is widely used in the sheet metal forming industry. This study attempts to relate the edge stretchability in collar forming to the strain hardening along the pierced edge; thus, Finite Element (FE) simulations can be used to reduce the number of experiments required to improve cutting settings for a given material and thickness. Using a complex-phase steel, CP-W 800 with thickness of 4.0 mm, a single-stage piercing operation is compared with a two-stage piercing operation, so called shaving, in terms of strains along the pierced edge, calculated by FE simulation. Results indicated that strains were reduced along the pierced edge by shaving.

Many vehicles allow consumers to adapt the vehicle environment to their families’ needs by folding or removing one or more rear row seats. It is currently unclear how different seat configurations affect child restraint systems (CRS) installed in adjacent seats. The objective is to quantify CRS performance in far-side impacts when the seating position adjacent to the CRS is in its normal upright position, folded in half, or removed. Twelve tests were conducted. Second row seats from a recent model year minivan were obtained, including full size captain’s chairs from the outboard positions and narrow seats from the center position. Rear-facing (RF) and forward-facing (FF) CRS were installed one at a time in either the outboard or center position. The seating position adjacent to the CRS was set in either the standard upright position, folded in half, or removed. Far-side impacts were conducted at 10° anterior of pure lateral at 24.8 ± 0.2 g. The Q3s ATD was used for all tests.

Characterization of the plastic and ductile fracture behavior of a ferrous casting commonly used for the steering knuckle of an automotive suspension system is presented in this work. Ductile fracture testing for various coupon geometries was conducted to simulate a wide range of stress states. Failure data for the higher stress triaxiality were obtained from tension tests conducted on thin flat specimens, wide flat specimens and axisymmetric specimens with varying notch radii. The data for the lower triaxiality were generated from thin-walled tube specimens subjected to torsional loading and compression tests on cylindrical specimens. The failure envelopes for the material were developed utilizing the test data and finite element (FE) simulations of the corresponding test specimens. Experiments provided the load-displacement response and the location of fracture initiation.

The National Highway Traffic Safety Administration (NHTSA) has developed the Large Omnidirectional Child (LODC) Anthropomorphic Test Device (ATD) to improve the biofidelity of the currently available Hybrid III 10-year-old (HIII-10C) ATD. The improvements of the LODC over the HIII-10C include changes in sub-assemblies such as the head and neck, where the LODC head is a redesigned HIII-10C head with pediatric mass properties and the neck has a modified atlanto-occipital joint to replicate observations made from human specimens. The current study focuses on developing a dynamic, nonlinear finite element (FE) model of the LODC ATD head and neck complex. The FE mesh is generated using HyperMesh based on the three-dimensional CAD model. The material data, contact definitions and initial conditions are defined in LS-PrePost and converted to LS-Dyna solver input format. The initial and boundary conditions are defined to replicate the neck flexion experimental tests.

To improve the biofidelity of the currently available Hybrid III 10-year-old (HIII-10C) Anthropomorphic Test Device (ATD), the National Highway Traffic Safety Administration (NHTSA) has developed the Large Omnidirectional Child (LODC) ATD. The LODC head is a redesigned HIII-10C head with mass properties and modified skin material required to match pediatric biomechanical impact response targets from the literature. A dynamic, nonlinear finite element (FE) model of the LODC head has been developed using the mesh generating tool Hypermesh based on the three-dimensional CAD model. The material data, contact definitions, and initial conditions are defined in LS-PrePost and converted to LS-Dyna solver input format. The aluminum head skull is stiff relative to head flesh material and was thus modeled as a rigid material. For the actual LODC, the head flesh is form fit onto the skull and held in place through contact friction.

Road Departure Mitigation System (RDMS) is a new feature in vehicle active safety systems. It may not rely only on the lane marking for road edge detection, but other roadside objects This paper discusses the radar aspect of the RDMS testing on roads with grass road edges. Since the grass color may be different at different test sites and in different seasons, testing of RDMS with real grass road edge has the repeatability issue over time and locations. A solution is to develop surrogate grass that has the same characteristics of the representative real grass. Radar can be used in RDMS to identify road edges. The surrogate grass should be similar to representative real grass in color, LIDAR characteristics, and Radar characteristics. This paper provides the 24 GHz and 77 GHz radar characteristic specifications of surrogate grass.

Due to the lack of biofidelity seen in GHBMC M50-O in rear-facing impact simulations involving interaction with the seat back in an OEM seat, it is important to explore how the boundary conditions might be affecting the biofidelity and potentially formulate methods to improve biofidelity of different occupant models in the future while also maintaining seat validity. This study investigated the influence of one such boundary condition, which is the seat back foam material properties, on the thorax and pelvis kinematics and injury outcomes of the GHBMC 50th M50-O model in a high-speed rear-facing frontal impact scenario, which involves severe occupant loading of the seat back. Two different seat back foam materials were used – a stiff foam with high densification and a soft foam with low densification. The peak magnitudes of the T-spine resultant accelerations of the GHBMC M50-O increased with the use of soft foam as compared to stiff foam.