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Technical Paper

Truck Brake Failure: Differences between Failure Modes for Drum and Disc Brakes

2018-04-03
2018-01-0528
On-highway heavy trucks are fitted with air disc brakes with increasing frequency. Disc brakes and traditional air drum brakes have different adjustment and heat dissipation characteristics. These differences lead to different failure modes when overheated. This paper describes how adjustment and other in-use factors affect the general braking capability of on-highway trucks fitted with disc and drum brakes. Simulations of a loaded tractor-trailer on a long, down-hill grade are used to predict brake temperature increase over time, and how that temperature increase can result in a runaway condition. The tractor and trailer are modeled with both traditional drum brakes and new disc brakes to illustrate operational differences between the two brake types.
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

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

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

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

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

Dual Fuel Methanol and Diesel Direct Injection HD Single Cylinder Engine Tests

2018-04-03
2018-01-0259
Laws concerning emissions from heavy duty (HD) internal combustion engines are becoming increasingly stringent. New engine technologies are needed to satisfy these new requirements and to reduce fossil fuel dependency. One way to achieve both objectives can be to partially replace fossil fuels with alternatives that are sustainable with respect to emissions of greenhouse gases, particulates and nitrogen oxides (NOx). A suitable candidate is methanol. The aim of the study presented here was to investigate the possible advantages of combusting methanol in a heavy duty Diesel engine. Those are, among others, lower particulate emissions and thereby bypassing the NOx-soot trade-off. Because of methanol’s poor auto-ignition properties, Diesel was used as an igniting sources and both fuels were separately direct injected. Therefore, two separate standard common rail Diesel injection systems were used together with a newly designed cylinder head and adapted injection nozzles.
Technical Paper

Experimental Study on Diesel Spray Characteristics at Different Altitudes

2018-04-03
2018-01-0308
In this study, effects of altitude on free diesel spray morphology, macroscopic spray characteristics and air-fuel mixing process were investigated. The diesel spray visualization experiment using high-speed photography was performed in a constant volume chamber which reproduced the injection diesel-like thermodynamic conditions of a heavy-duty turbocharged diesel engine operating at sea level and 1000 m, 2000 m, 3000 m and 4500 m above sea level. The results showed that the spray morphology became narrower and longer at higher altitude, and small vortex-like structures were observed on the downstream spray periphery. Spray penetration increased and spray angle decreased with increasing altitude. At altitudes of 0 m, 1000 m, 2000 m, 3000 m and 4500 m, the spray penetration at 1.45 ms after start of injection (ASOI) were 79.54 mm, 80.51 mm, 81.49 mm, 83.29 mm and 88.92 mm respectively, and the spray angle were 10.9°, 10.8°, 10.7°, 10.4°and 9.8° respectively.
Technical Paper

Evaluation of Shot-to-Shot In-Nozzle Flow Variations in a Heavy-Duty Diesel Injector Using Real Nozzle Geometry

2018-04-03
2018-01-0303
Cyclic variability in internal combustion engines arises from multiple concurrent sources, many of which remain to be fully understood and controlled. This variability can, in turn, affect the behavior of the engine resulting in undesirable deviations from the expected operating conditions and performance. Shot-to-shot variation during the fuel injection process is strongly suspected of being a source of cyclic variability. This study focuses on the shot-to-shot variability of injector needle motion and its influence on the internal nozzle flow behavior using diesel fuel. High-speed x-ray imaging techniques have been used to extract high-resolution injector geometry images of the sac, orifices, and needle tip that allowed the true dynamics of the needle motion to emerge. These measurements showed high repeatability in the needle lift profile across multiple injection events, while the needle radial displacement was characterized by a much higher degree of randomness.
Technical Paper

Fuel Consumption and Performance Benefits of Electrified Powertrains for Transit Buses

2018-04-03
2018-01-0321
This study presents a process to quantify the fuel saving potential of electrified powertrains for medium and heavy duty vehicles. For this study, equivalent vehicles with electrified powertrains are designed with the underlying principle of not compromising on cargo carrying capacity or performance. Several performance characteristics, that are relevant for all types of medium and heavy duty vehicles, were identified for benchmarking based on the feedback from the industry. Start-stop hybrids, parallel pre-transmission hybrids, plug-in hybrids, and battery electric vehicles are the technology choices in this study. This paper uses one vehicle as an example, explains the component sizing process followed for each powertrain, and examines each powertrain’s fuel saving potential. The process put forth in this paper can be used for evaluating vehicles that belong to all medium and heavy duty classes.
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

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

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

A Technical, Environmental and Financial Analysis of Hybrid Buses Used for Public Transport

2018-04-03
2018-01-0424
This paper presents a technical, financial and environmental analysis of four different hybrid buses operated under Buenos Aires driving conditions. A conventional diesel bus is used as reference and three electric hybrids equipped with different energy storage technologies, Li-Ion, NiMH batteries and double layer capacitors (ultracapacitors), are evaluated, along with a hydraulic hybrid platform which uses high-pressure accumulators as its energy buffer. The operating conditions of the buses are set using real driving GPS data collected from various bus routes within the city. The different vehicle platforms are modeled on AUTONOMIE SA and validated by comparing the obtained fuel consumption results to those reported by local transport authorities and values found in the literature. The embedded energy and CO2 emissions of each platform are estimated using GREET and the total cost of ownership of each vehicle is calculated and compared to that of the conventional bus.
Technical Paper

Preliminary Study of LIDAR Scanner-Based Collision Avoidance and Automated Guided Systems for Autonomous Power Equipment Products

2018-04-03
2018-01-0032
Technology is continuously being developed to prevent self-driving vehicles from crashing. That technology could also be considered for other autonomous products. Collision avoidance in automated, guided systems using a light detection and ranging (LIDAR) scanner has been studied for application in low-speed autonomous Honda Power Equipment products, such as self-driving lawn mowers. The automotive application of a LIDAR scanner for autonomous driving is used for obstacle detection and offline local area. Such delineations do not exist in areas where power equipment is used, such as grass fields; therefore, identifying object height and distance, is a relatively new area. For this study, a small LIDAR scanner with a resolution of 0.01 m and a measurement range of 0.05 m to 40.00 m was used on a Honda self-driving lawn mower. The measurement distance data was directly processed in the scanner, enabling the drive unit to obtain distance information during actual operation.
Technical Paper

GPS Guided Autonomous Navigation of a Small Agricultural Robot with Automated Fertilizing System

2018-04-03
2018-01-0031
In this paper, the design, implementation, and testing of an autonomous agricultural robot with GPS guidance is presented. This robot is also responsible for weed detection and killing by spraying appropriate herbicide as well as fertilizing. This rover is powered by 5 12 V electric bike batteries and two electric motors. Machine learning algorithms such as Haar feature-based cascade classifiers has been utilized to detect three kinds of common weeds found in a corn field. The robot control system consists of GPS guided control of propulsion system and steering actuators, an image processing and detection system, and a spray control system for herbicide and fertilizer applications. Multiple microprocessors such as Raspberry Pi 3, Arduino, as well as an on-board computer have used to provide all control functions in an integrated fashion. Open sources software such as Mission Planner and ReachView have been used to provide autonomous guidance of the vehicle.
Technical Paper

Development and Optimization of Variable Flow AC Compressor for Commercial Vehicles to Reduce Parasitic Losses and Improving Efficiency of HVAC System

2018-04-03
2018-01-0056
In the modern era of commercial vehicle industry, passenger and driver comfort is one of the major parameters that improves vehicle running time which leads to fleet owner’s profitability. Air conditioning system is one such system whose primary function is to provide the required cooling inside the cabin in hot weather conditions. An Air-conditioned truck cabin creates a comfortable environment for the driver which increases his efficiency and reduces fatigue. An AC compressor consumes power directly from the engine affecting fuel economy and vehicle performance. With ever increasing demand for energy efficient systems and thermal comfort in automobiles, AC systems should be able to deliver the required cooling performance with minimum power consumption. Therefore, reducing AC power consumption in vehicles is one of the key challenges faced by climate control engineers.
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