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Safety and minimal transit time are vital during transportation of essential commodities and passengers, especially in winter conditions. Icy roads are the worst driving conditions with the least available friction, leaving valuable cargo and precious human lives at stake. The study investigates the available friction at the tire-ice interface due to changes in key operational parameters. Experimental analysis of tractive performance of tires on ice was carried out indoor, using the terramechanics rig located at the Advanced Vehicle Dynamics Laboratory (AVDL) at Virginia Tech. The friction-slip ratio curves obtained from indoor testing were inputted into TruckSIM, defining tire behavior for various ice scenarios and then simulating performance of trucks on ice. The shortcomings of simulations in considering the effects of all the operational parameters result in differences between findings of indoor testing and truck performance simulations.

Studying the kinetic and kinematics of the rim-tire combination is very important in full vehicle simulations, as well as for the tire design process. Tire maneuvers are either quasi-static, such as steady-state rolling, or dynamic, such as traction and braking. The rolling of the tire over obstacles and potholes and, more generally, over uneven roads are other examples of tire dynamic maneuvers. In the latter case, tire dynamic models are used for durability assessment of the vehicle chassis, and should be studied using high fidelity simulation models. In this study, a three-dimensional finite element model (FEM) has been developed using the commercial software package ABAQUS. The purpose of this study is to investigate the tire dynamic behavior in multiple case studies in which the transient characteristics are highly involved.

Modeling the tire forces and moments (F&M) generation, during combined slip maneuvers, which involves cornering and braking/driving at the same time, is essential for the predictive vehicle performance analysis. In this study, a new semi-empirical method is introduced to estimate the tire combined slip F&M characteristics based on flat belt testing machine measurement data. This model is intended to be used in the virtual tire design optimization process. Therefore, it should include high accuracy, ease of parameterization, and fast computational time. Regression is used to convert measured F&M into pure slip multi-dimensional interpolant functions modified by weighting functions. Accurate combined slip F&M predictions are created by modifying pure slip F&M with empirically determined shape functions. Transient effects are reproduced using standard relaxation length equations. The model calculates F&M at the center of the contact patch.

Models for off-road vehicles, such as farm equipment and military vehicles, require an off-road tire model in order to properly understand their dynamic behavior on off-road driving surfaces. Extensive literature can be found for on-road tire modeling, but not much can be found for off-road tire modeling. This paper presents an off-road tire model that was developed for use in vehicle handling studies. An on-road, dry asphalt tire model was first developed by performing rolling road force and moment testing. Off-road testing was then performed on dirt and gravel driving surfaces to develop scaling factors that explain how the lateral force behavior of the tire will scale from an on-road to an off-road situation. The tire models were used in vehicle simulation software to simulate vehicle behavior on various driving surfaces. The simulated vehicle response was compared to actual maximum speed before sliding vs. turning radius data for the studied vehicle to assess the tire model.

A graphical user interface (GUI) toolbox called Vehicle System Simulator (VSS) is developed in MATLAB to ease the use of this vehicle model and hopefully encourage its widespread application in the future. This toolbox uses the inherent MATLAB discrete-time solvers and is mainly based on Level-2 s-function design. This paper describes its built-in vehicle dynamics model based on multibody dynamics approach and nonlinear tire models, and traction/braking control systems including Cruise Control and Differential Braking systems. The built-in dynamics model is validated against CarSim 8 and the simulation results prove its accuracy. This paper illustrates the application of this new MATLAB toolbox called Vehicle System Simulator and discusses its development process, limitations, and future improvements.

Human expert drivers have the unique ability to combine correlated sensory inputs with repetitive learning to build complex perceptive models of the vehicle dynamics as well as certain key aspects of the tire-ground interface. This ability offers significant advantages for navigating a vehicle through the spatial and temporal uncertainties in a given environment. Conventional traction control algorithms utilize measurements of wheel slip to help insure that the wheels do not enter into an excessive slip condition such as burnout. This approach sacrifices peak performance to ensure that the slip limits are generic enough suck that burnout is avoided on a variety of surfaces: dry pavement, wet pavement, snow, gravel, etc. In this paper, a novel approach to traction control is developed using an anthropomimetic control synthesis strategy.

In order to evaluate a human surrogate, the human and surrogate response must be defined. The purpose of this study was to evaluate the response of cadaver subjects to blunt impacts to the frontal bone, nasal bone and maxilla. Force-displacement corridors were developed based on the impact response of each region. Variation in the force-displacement response of the cadaver subjects due to the occurrence of fracture and fracture severity was demonstrated. Additionally, impacts were performed at matched locations using the Facial and Ocular CountermeasUre Safety (FOCUS) headform. The FOCUS headform is capable of measuring forces imposed onto facial structures using internal load cells. Based on the tests performed in this study, the nasal region of the FOCUS headform was found to be the most sensitive to impact location. Due to a wide range in geometrical characteristics, the nasal impact response varied significantly, resulting in wide corridors for human response.

Due to the large negative impact of combustion gas emissions on air quality and the more stringent environmental legislation, research on internal combustion engines (ICE) are being developed to reduce emissions of pollutant gases to the atmosphere. One of the research fronts is the use of lean mixtures with the pre-chamber ignition system (PCIS). This system consists of a pre-chamber (PC) connected to the main chamber by one or more interconnecting holes. A spark plug initiates combustion of the mixture present in the pre-chamber, which is propagated as gas jet into the main chamber, igniting the lean mixture present therein. The gas jets have high thermal and kinetic energy, which promote faster combustion duration, making the system less prone to knock and with lower cyclic variability of the IMEP, enabling the lean limit extension. The pre-chamber system can be assisted with a supplementary liquid or gaseous fuel injection, enabling the charge stratification.

Atmospheric pollution is the major public health issue in many cities around the world. Internal combustion engines (ICE) and industries are common sources of pollutants that aggravate this situation. Aiming to overcome this problem, increasingly restrictive legislation on combustion pollutant emissions has been formulated and new technologies are being developed to ensure compliance with such restrictions. In this scenario, the lean mixtures appear as a possible alternative, but also bring some inconveniences such as combustion instabilities. Pre-chamber ignition systems (PCIS) enable a more stable combustion process due to high kinetic, thermal and chemical energy of the gases from the pre-chamber (PC), which pass through nozzles and begin the combustion process of the air-fuel mixture contained in the main combustion chamber (MC). However, some challenges still have to be overcome in the development of these systems, one of the main ones being hydrocarbon (HC) emissions.

In this paper a yaw stability control algorithm along with an emergency roll control strategy have been developed. The yaw stability controller and emergency roll controller were both developed using linear two degree-of-freedom vehicle models. The yaw stability controller is based on Lyapunov stability criteria and uses vehicle lateral acceleration and yaw rate measurements to calculate the corrective yaw moment required to stabilize the vehicle yaw motion. The corrective yaw moment is then applied by means of a differential braking strategy in which one wheel is selected to be braked with appropriate brake torque applied. The emergency roll control strategy is based on a rollover coefficient related to vehicle static stability factor. The emergency roll control strategy utilizes vehicle lateral acceleration measurements to calculate the roll coefficient. If the roll coefficient exceeds some predetermined threshold value the emergency roll control strategy will deploy.

For many years durability tests engineers have worked in the sense of improving the tests that, at first, were performed using public roads with high time consumption and low reproducibility. Proving grounds were specially designed to reproduce the most important efforts to the body and chassis systems, but time problem was still there. Time and cost reduction allied to the needs of quality, reliability and reproducibility improvement led the engineers to develop methods and equipments to reproduce the durability tests in the lab. In this way the road simulators appear as a powerful tool able to perform durability tests with high reliability, self-controlled and with very low time compared to the road tests. At this scenery bench tests were also created to components and systems mainly used to anticipate problems before a whole vehicle test.

The torch ignition system consists in the inflammation of the air/fuel mixture by means of gases jet flames that constitute ignition lines. Engines with this feature have a cavity or combustion pre-chamber, physically separate from the main chamber. In these systems happens a larger turbulence generation, due the movement of the gases inside the pre-chamber and through the interconnection orifices. The charge stratification, by means of an auxiliary inlet fuel system, also contributes for the fast and insurance inflammation of lean mixtures and the most varied combustible, including the difficult direct spark ignition fuels. This work presents the design elaboration of combustion pre-chamber from an analysis of the influence of the main constructive parameters in the combustion process.

Computer simulations, dummy experiments with a new enhanced upper extremity, and small female cadaver experiments were used to analyze the small female upper extremity response under side air bag loading. After establishing the initial position, three tests were performed with the 5th percentile female hybrid III dummy, and six experiments with small female cadaver subjects. A new 5th percentile female enhanced upper extremity was developed for the dummy experiments that included a two-axis wrist load cell in addition to the existing six-axis load cells in both the forearm and humerus. Forearm pronation was also included in the new dummy upper extremity to increase the biofidelity of the interaction with the handgrip. Instrumentation for both the cadaver and dummy tests included accelerometers and magnetohydrodynamic angular rate sensors on the forearm, humerus, upper and lower spine.

The accuracy of computer-based ground vehicle durability and ride quality simulations depends on accurate representation of road surface topology as vehicle excitation data since most of the excitation exerted on a vehicle as it traverses terrain is provided by the terrain topology. It is currently not efficient to obtain accurate terrain profile data of sufficient length to simulate the vehicle being driven over long distances. Hence, durability and ride quality evaluations of a vehicle depend mostly on data collected from physical tests. Such tests are both time consuming and expensive, and can only be performed near the end of a vehicle's design cycle. This paper covers the development of a methodology to synthesize terrain profile data based on the statistical analysis of physically measured terrain profile data.

The trends in the development of spark ignition engines leads to the adoption of lean mixtures in the combustion chamber. Torch ignition systems have potential to reduce simultaneously the NOx and CO emissions, while keeping the fuel conversion efficiency at a high level. This study aims to design and analyze a torch ignition system running with ethanol on lean homogeneous charge, adapted to an Otto cycle single-cylinder engine with optical visualization. The main objective is to achieve combustion stability under lean burn operation and to expand the flammability limit for increasing engine efficiency by means of redesigning the ignition system adapting a pre-chamber to the main combustion chamber. Experiments were conducted at constant speed (1000 rpm) using ethanol (E100) as fuel, for a wide range of injection, ignition and mixture formation parameters. Specific fuel consumption and combustion stability were evaluated at each excess air ratio.

Global climate change and an increasing energy demand are driving the scientific community to further advance internal combustion engine technology. Invented by Sr. Henry Ricardo in 1918 the torch ignition system was able to significantly decrease engine’s fuel consumption and emission levels. Since the late 70s, soon after the Compound Vortex Controlled Combustion (CVCC) created by Honda, the torch ignition system R&D almost ceased due to the issues encountered by very complex and costly mechanic control systems that time. This work presents a stratified torch ignition prototype endowed with a sophisticated electronic control systems and components such as electro-injectors from direct injection systems placed on the pre-combustion chamber. The torch ignition prototype was tested and its performance are presented and compared with the baseline engine, which was used as a workhorse for the prototype engine construction.

Resistive forces are a great source of fuel consumption in vehicles. In particular, rolling resistance represent the major resistance force at low speeds. It is highly influenced by the inflation pressure of the tire and vertical load over it. In the present work, a computer model is created with the objective of investigating the influence of tire inflation pressure on fuel consumption and rolling resistance force. Pressure is varied and parameters analyzed at different vehicle speeds for two different calculation methods. Results show significant decrease in fuel consumption and rolling resistance force as inflation pressure is augmented.

For metallic tanks in contact with aqueous solution, it is always observed the presence of electrochemical corrosion. This process can cause both economic and environmental damage. In the automotive industry, fuel tanks systems have been studied in order to propose new materials to replace the plastic tanks or tanks with metallic coatings. Plastic tanks have the disadvantage of not being recyclable. In the other hand, for metallic coated tanks, tin is used as a coat material and, for this reason, the external tank side must be painted, making its productive process more expensive and generating higher amount of waste. Nowadays, organic-metallic coated tanks, in which, nickel and aluminum are the metals present, can be found. These coatings show potential application; because they do not use heavy metals in their composition and they do not require external painting, allowing a lower production cost.

The automobile industry and its growing commitment to the environment have collaborated in the development of technologies to reduce emissions of gaseous pollutants, including hydrocarbons. Recent works are aimed at the development of the torch ignition in internal combustion engines of the Otto cycle. A prototype characterized by a torch ignition system with fixed geometry of pre-chamber per cylinder, with a volume of 3.66 cm3 and a single nozzle with a diameter of 6.00 mm, fed with homogeneous mixture originating from Combustion chamber. The ignition and injection system was controlled by a reprogrammable electronic management system. The main results were an increase of around 10% in thermal efficiency and reductions of up to 91% in carbon monoxide emissions, but there was a considerable increase in total hydrocarbons (THC) emissions.

The goal of this paper is to estimate near-side injury risk in vehicles with the best side impact performance in the U.S. New Car Assessment Program (NCAP). The longer-term goal is to predict the incidence of crashes and injury outcomes in the U.S. in a future fleet of the 2025-time frame after current active and passive safety countermeasures are fully implemented. Our assumption was that, by 2025, all new vehicles will have side impact passive safety performance equivalent to current U.S. NCAP five star ratings. The analysis was based on real-world crashes extracted from case years 2010-2015 in the National Automotive Sampling System / Crashworthiness Data System (NASS/CDS) in which front-row occupants of late-model vehicles (Model Year 2011+) were exposed to a near-side crash.