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Technical Paper

Videogrammetry in Vehicle Crash Reconstruction with a Moving Video Camera

2018-04-03
2018-01-0532
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. Available 3D modeling software can be used to virtually match photographs or fixed-location video surveillance footage. Dash- or vehicle-mounted camera systems are increasingly being used in light vehicles, commercial vehicles and locomotives. 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. The literature to date describes using still photos to locate fixed objects, using video taken from stationary camera locations to determine the speed of moving objects or using video taken from a moving vehicle to locate fixed objects.
Technical Paper

Passenger Vehicle-Motorcycle Pre-Crash Trajectory Reconstruction and Conflict Analysis Results Based On an Extended Application of the Honda-DRI ACAT Safety Impact Methodology

2018-04-03
2018-01-0510
Advanced Crash Avoidance Technologies (ACATs) such as Forward Collision Warning (FCW) and Automatic Emergency Braking (AEB) have been developed for light passenger vehicles (LPVs) to avoid and mitigate collisions with other road users and objects. However the number of motorcycle (MC) crashes, injuries, and fatalities in the United States has remained relatively constant. To fully realize potential safety benefits, advanced driver assistance systems and future automated vehicle technologies also need to be effective in avoiding collisions with motorcycles. Towards this goal the Honda-DRI ACAT Safety Impact Methodology (SIM), which was previously developed to evaluate LPV ACAT system effectiveness in avoiding and mitigating collisions with fixed objects, other LPVs, and pedestrians, is being extended to also evaluate the effectiveness of ACATs in avoiding and mitigating LPV-MC collisions.
Technical Paper

Truck and Sport Utility Vehicle Front End Stiffness Corridors

2018-04-03
2018-01-0518
The purpose of this study was to characterize front stiffness response of contemporary sport utility vehicles (SUVs) and trucks. Vehicle front impact test data were obtained from data published by the National Highway Traffic Safety Administration [NHTSA]. For all tests, force data were obtained from barrier load cells and stroke data were derived from accelerometers. Data from 53 truck and SUV tests were aggregated by vehicle product segment according to body style to obtain mean ± standard deviation (SD) stiffness corridors: (1) compact unibody SUV/crossover, (2) small unibody SUV/crossover, (3) mid-size unibody SUV/crossover, (4) frame SUV, and (5) frame truck. To compare between vehicle product segments, this study also considered the average stiffness (slope) within the stroke region required to achieve 300 kN total barrier force. Across unibody SUV segments, average stiffness varied from 1.4–1.8 kN/mm.
Technical Paper

Steering Shaft Separation with a Collision Involved Heavy Duty Steering Gear

2018-04-03
2018-01-0524
A crash of a medium duty truck led to a study of the failure mechanism of the truck’s steering system. The truck, after being involved in a multi-vehicle vehicle collision, was found with its steering input shaft disconnected from the steering gear. The question arose whether the steering gear failure was a result of the collision, or causative to the collision. An in-depth investigation was conducted into whether forces on the vehicle due to the collision could cause the steering shaft to separate from the steering gear. Additionally, the performance of the steering gear with the adjuster nut progressively backed off was studied to determine the feedback a driver would receive if the steering gear came progressively apart. From the results of these studies, conclusions with regard to the crash causation were reached.
Technical Paper

Experimental Investigation of the Aerodynamic Benefits of Truck Platooning

2018-04-03
2018-01-0732
Lawrence Livermore National Laboratory (LLNL) has conducted a series of scaled wind tunnel tests to investigate the aerodynamic benefits of heavy vehicle platooning and the availability of cooling air for trailing vehicles on two- and three-vehicle platoons. To measure the aerodynamic drag, scale models are mounted onto a LLNL designed splitter plate by means of a low-friction linear bearing and a load cell located within each model trailer. In addition to drag, pressure measurements are made with a pitot probe positioned at the center of each model radiator grill. Particle Image Velocimetry (PIV) and Infrared Thermography (IRT) measurements are used to map the three-dimensional velocity field and flow structures around the vehicles.
Technical Paper

Simplifications Applied to Simulation of Turbulence Induced by a Side View Mirror of a Full-Scale Truck Using DES

2018-04-03
2018-01-0708
In this paper, the turbulent flow induced by a production side-view mirror assembled on a full-scale production truck is simulated using a compressible k-ω SST detached eddy simulation (DES) approach -- the improved delayed DES (IDDES). The truck configuration consists of a compartment and a trailer. Due to the large size and geometric complexity of the configuration, some simplifications are applied to the simulation. A purpose of this work is to investigate whether the simplifications are suitable to obtain the reasonable properties of the flow near the side-view mirror. Another objective is to study the aerodynamic performances of the mirror. The configuration is simplified regarding two treatments. The first treatment is to retain the key exterior components of the truck body while removing the small gaps and structures. Furthermore, the trailer is shaped in an apex-truncated square pyramid.
Technical Paper

Investigation and Development of Underbody Aerodynamic Drag Reduction Devices for Trailer Trucks

2018-04-03
2018-01-0707
It is well known that the underbody region of a tractor-trailer is responsible for up to 30% of the aerodynamic drag. This is the highest drag created by any region of a tractor-trailer. There are a number of underbody drag-reduction devices available on the market but they create a few operational issues, such as low ground clearance and ice collection, which inhibit their mass market appeal. In this paper, a novel concept of an underbody aerodynamic device is developed and investigated. The underbody device is a combination of a ramp and a side skirt; which are optimized simultaneously. In addition, the device is made collapsible to facilitate easy storage when not in use (i.e., city driving). NASA’s Generic Conventional Model (GCM); a 1/8th scale model of a generic class-8 tractor-trailer is used to evaluate and optimize the concept. The GCM allows the concept to be applicable to a wider range of tractor-trailers.
Technical Paper

An Experimental Study of the Impact of Underbody Roughness on the Instantaneous Wake Flow Topology behind a Truck Geometry

2018-04-03
2018-01-0714
The turbulent wake behind a truck is responsible for a considerable proportion of the total aerodynamic drag. There is evidence to suggest that the underbody flow affects the wake topology, although this interaction is not well understood. Typical truck trailer underbodies are geometrically very complex and have a range of bluff bodies - such as the wheel and axle assembly, structural beams or the secondary fuel tank for refrigerated trucks - attached. These components block the underbody flow and erode its momentum. However, most of the previous studies of the wake flow have used models with clean underbodies. It is thus uncertain whether the wake shapes found by these studies accurately represent the wake topology behind a real truck with a detailed underbody.
Technical Paper

Study on Correlation between After-Treatment Performance and Running Conditions, Exhaust Parameters of Heavy-Duty Diesel Vehicle

2018-04-03
2018-01-0338
The increasingly stringent emission regulations have mandated the use of CCRT (catalyzed continuously regeneration trap) made by upstream DOC (diesel oxidation catalyst) and downstream CDPF (catalyzed diesel particulate filter) for heavy-duty diesel vehicles, which is proved to be the only way that can efficiently control the gaseous and particulate emissions. The performance of after-treatment is greatly influenced by the running conditions of the diesel vehicle and its exhaust parameters, so this paper intended to use grey relational analysis to study the correlation between running conditions (velocity, acceleration, VSP (vehicle specific power)), exhaust parameters (exhaust flow rate, DOC inlet temperature, concentrations of CO, THC, O2 and NOX) and the performance of DOC and CCRT based on chassis dynamometer test. Results showed that the effect of DOC on CO and THC is mainly affected by exhaust flow rate, exhaust temperature and THC concentration.
Technical Paper

Evaluation of Portable Number Emission Systems for Heavy-Duty Applications under Steady State and Transient Vehicle Operation Conditions on a Chassis Dynamometer

2018-04-03
2018-01-0348
The European Commission plans to introduce a (solid) particle number (PN) emission limit for type approval and in-service conformity (ISC) by the end of 2018 (Euro VI d) using PEMS (Portable Emission Measurement System) tests on heavy duty vehicles on the road. Performance, measurement accuracy and sensitivity of several on-board particle counters for heavy duty applications have not been tested yet in parallel on a chassis dyno with Euro VI vehicle (N3-class, 12.8 l). The PN PEMS examined were CPC (Condensation Particle Counter) and DC (Diffusion Charger) based. Evaluation was conducted at different ambient temperatures from −7 °C to 35 °C while running different test cycles: WHVC (World Harmonized Vehicle Cycle), steady state engine operation, active regeneration and ISC-tests. A particle number system following the current heavy duty regulation requirement and recommendations of the Particle Measurement Program (PMP) served as reference (PMP_TP).
Technical Paper

Improvement in Selective Catalytic Reduction Model Accuracy for Predicting NOx Conversion at High Temperature

2018-04-03
2018-01-0346
As a result of WNTE regulations and the introduction of close-coupled aftertreatment systems, exhaust purification at high temperatures in commercial vehicles has become increasingly important in recent years. In this report, we improve the prediction accuracy for NOx conversion at high temperatures in the kinetic model of conventional Cu-selective catalytic reduction (Cu-SCR). Reaction rate analysis indicated that the rate of NH3 oxidation was extremely low compared to the rate of standard SCR. We found that NOx concentration-dependent NH3 oxidations (termed NOx-assisted NH3 oxidations) were key to the rate of NH3 oxidation. The output of the improved Cu-SCR kinetic model was in agreed with experimental results obtained from the synthetic gas bench and engine dynamometer bench. We analyzed the contribution of each reaction to NH3 consumption during Cu-SCR. Under NH3 + NO + O2, standard SCR was dominant at low temperature.
Technical Paper

Solid Particle Number and Ash Emissions from Heavy-Duty Natural Gas and Diesel w/SCRF Engines

2018-04-03
2018-01-0362
Solid and metallic ash particle number (PN) and particulate matter (PM) mass emission measurements were performed on a heavy-duty (HD) on-highway diesel engine and a compressed natural gas (CNG) engine. Measurements were conducted under transient engine operation that included the FTP, WHTC and RMC. Both engines were calibrated to meet CARB ultra low NOX emission target of 0.02 g/hp-hr, a 90% reduction from current emissions limit. The HD diesel engine final exhaust configuration included a number of aftertreatement sub-systems in addition to a selective catalytic reduction filter (SCRF). The stoichiometric CNG engine final configuration included a closed coupled Three Way Catalyst (ccTWC) and an under floor TWC (ufTWC). The aftertreatment systems for both engines were aged for a full useful life (FUL) of 435,000 miles, prior to emissions testing. PM mass emissions from both engines were comparable and well below the US EPA emissions standard.
Technical Paper

Sodium Cooling Efficiency in Hollow Valves for Heavy Duty Engines

2018-04-03
2018-01-0368
As a consequence of the ongoing evolution of engines, where performance is continuously improving and the use of alternative fuels is being adopted by many engine manufacturers, thermal working conditions of the exhaust valves are increasingly critical. In order to better resist the higher temperature levels of the exhaust gases, current development ranges from improvement of the cooling concept for the overall system, new materials for valve set components up to the upgrade of the exhaust manifold material. Change in the design of several valvetrain components due to the increased thermal loads is a logical consequence of this technical evolution process. Hollow exhaust valves filled with Sodium (Na) are a known technology that is widely used in passenger car engines to improve thermal behavior and to avoid the need to change to expensive materials (Ni-base alloys).
Technical Paper

Integrated Exhaust Rocker Arm Lost Motion Compression Release Engine Brake with Novel Reset Mechanism for Heavy Duty Diesel Engines

2018-04-03
2018-01-0381
A new compression release engine brake system has been developed which utilizes the well-known lost motion idea along with an entirely new valve resetting mechanism. The engine brake is fully integrated into the exhaust rocker arm, making it highly compact. The novel reset mechanism provides a pressure sensing reset timing which optimizes engine brake performance and valve train stress at all engine speeds. Hydraulic system simulation studies were performed to first verify the concept on paper. Once acceptable performance was predicted, physical prototypes were produced. The Cummins ISL 8.9 L engine was chosen as a proof of concept platform due to its availability and its factory engine brake option. The factory engine brake gives a data set for comparison while validating this new technology. All targets for engine brake function were achieved, and a substantial increase in performance was demonstrated.
Technical Paper

Electro-Hydraulic Shuttle Transmission and Control for Tractors with Non-Electronic Engine

2018-04-03
2018-01-0390
Recently, emerging technological developments in powertrain were mostly accompanied with electronics for efficient and precise control of various powertrain systems like engine, transmission, hydraulics, etc. Agricultural tractors are of no exception to this context. Most of the higher horsepower tractors above 50 HP are equipped with modern transmission systems such as Power-shuttle, Power-shift etc. having their wet clutch transmission and diesel engine controlled by an Electronic Control Unit. This is possible only with an engine that receives and provides electronic signals. Whereas a tractor with mechanical (non-electronic) engine is of predominant use in the Indian farm lands due to their low cost and immediate availability compared to that of an engine equipped with high-end electronics. Hence, there is a demand for low cost drivetrain with improved controls and without engine electronics.
Technical Paper

Conceptual Design Challenges and Solutions in Power Shuttle Transmission Development for Legacy Tractors

2018-04-03
2018-01-0394
Current developments in tractor transmission design has galloped to new heights with the introduction of CVT, Power shift, Power shuttle, hydrostatic etc besides the vastly available synchromesh and constant-mesh gearboxes. In contrary to the above existing facts of new powertrain development, there is a definite market need to revamp the heritage tractor models to be equipped with the modern transmission systems. This will help customers to have the advanced drivetrain features in the legacy tractors that have won many hearts. One such modernization was the development of new power shuttle transmission in legacy tractor models for TAFE tractors. Power shuttle primarily enables a tractor - in this case, to go forward and reverse by operating a wet clutch. A flick of lever, usually on the steering column changes the direction of the tractor at the same speed of the gear selected.
Technical Paper

Towards Electrification of Urban Buses Using Model Based Analysis

2018-04-03
2018-01-0408
City buses electrification gains increasing interest as a promising solution for both zero emissions in urban environment and energy consumption minimization. Nevertheless, global spread of battery electric buses may be currently questionable, mainly due to traveling range limitations. In this respect, the aim of this work is to elucidate performance aspects of battery electric powertrain systems for urban buses. Instead of exhaustive testing, cost-effective model based vehicle analysis is proposed for quantifying and understanding electric propulsion system performance and respective vehicle energy consumption. First, an indicative 12-m battery electric urban bus model was developed and its performance was simulated under both steady state conditions, as well as the legislated Braunschweig driving cycle.
Technical Paper

Evaluation of the Technical Level of Modern Agricultural Tractors Represented in the Russian Market

2018-04-03
2018-01-0657
The paper considers a new technique for assessing the technical level of agricultural tractors competing in one power range. The existing methods of evaluation of technical level, both in Russia and abroad, are associated with expert approach that is limited by the qualitative nature of conclusions, which does not allow to predict quantitative change in performance. In this regard, if there are up to 35 models in the Russian market with equal power capabilities, the problem of making a choice arises. A general indicator of technical level is the ratio of the replacement capacity of the arable unit based on a tractor model under consideration to the replacement capacity of the arable unit based on a reference tractor, which are determined by computer simulation in reference conditions.
Technical Paper

Durability Studies on Gas Engine Oil along with Performance and Emission Characteristics of Heavy Duty Turbocharged Natural Gas Powered Engine

2018-04-03
2018-01-0638
Natural gas has been considered and implemented as alternative fuel to gasoline and diesel powered vehicles worldwide. Although natural gas belongs to petroleum fuel family, it has considerable recourses worldwide to ensure long energy security and comparatively lower carbon to hydrogen ratio that make it more environment friendly. This paper presents the effect of long duration endurance test on gas engine oil along with performance and emission characteristics of 5.8 L turbocharged heavy duty natural gas engine. The six cylinder engine was chosen due to its importance for urban bus transportation. The engine was subjected to long duration endurance test of 800 hrs with closed loop monitoring and controlled conditions as per 6 mode engine load cycle. During the complete endurance test of 800 hours, performance and emission characteristics of the engine were analyzed after completion of every 100 hours as per Full Throttle Performance Test and European Transient Cycle (ETC).
Technical Paper

Infrared Borescopic Analysis of Ignition and Combustion Variability in a Heavy-Duty Natural-Gas Engine

2018-04-03
2018-01-0632
Optical imaging diagnostics of combustion are most often performed in the visible spectral band, in part because camera technology is most mature in this region, but operating in the infrared (IR) provides a number of benefits. These benefits include access to emission lines of relevant chemical species (e.g. water, carbon dioxide, and carbon monoxide) and obviation of image intensifiers (avoiding reduced spatial resolution and increased cost). High-speed IR in-cylinder imaging and image processing were used to investigate the relationships between infrared images, quantitative image-derived metrics (e.g. location of the flame centroid), and measurements made with in-cylinder pressure transducers (e.g. coefficient of variation of mean effective pressure). A 9.7-liter, inline-six, natural-gas-fueled engine was modified to enable exhaust-gas recirculation (EGR) and provide borescopic optical access to one cylinder for two high-speed infrared cameras.
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