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An investigation into two new control strategies for the vehicle Anti-lock Braking System (ABS) are made for a possible replacement of current non-optimal slip control methods. This paper applies two techniques in order to maximize the braking force without any wheel locking. The first considers the power dissipated by the brake actuator. This power method does not use slip to construct its reference signal for control. A heuristic approach is taken with this algorithm where one searches for the maximum power dissipated. This can open up easier implementation of regenerative braking concurrently with ABS on an electro-hydraulic braking system. Parameter scheduling is explored in this algorithm. The second algorithm employs the use of perturbation based Extremum Seeking Control (ESC) to provide a reference slip and a Youla controller in a negative feedback loop.

Biofuels, such as ethanol and butanol, have been the subject of significant political and scientific attention, owing to concerns about climate change, global energy security, and the decline of world oil resources that is aggravated by the continuous increase in the demand for fossil fuels. This study evaluated the potential emissions impacts of different alcohol blends on a fleet of modern gasoline vehicles. Testing was conducted on a fleet of nine vehicles with different combinations of ten fuel blends over the Federal Test Procedure and Unified Cycle. The vehicles ranged in model year from 2007-2014 and included four vehicles with port fuel injection (PFI) fueling and five vehicles with direct injection (DI) fueling. The ten fuel blends included ethanol blends at concentrations of 10%, 15%, 20%, 51%, and 83% by volume and iso-butanol blends at concentrations of 16%, 24%, 32%, and 55% by volume, and an alcohol mixture giving 10% ethanol and 8% iso-butanol in the final blend.

Steady-state, transient and dithering characteristics of emission conversion efficiencies of three-way catalysts on natural gas IC engine were investigated experimentally on a single-cylinder CFR engine test bench. Steady-state runs were conducted as references for specific engine emission levels and corresponding catalyst capacities. The steady-state data showed that conversion of HC will be the major problem since conversion of HC was effective only for a very narrow range of exhaust mixture. Unsteady exploration runs with both lean-to-rich and rich-to-lean transitions were conducted. These results were interpreted with a time scale analysis, according to which a qualitative oxygen storage model was proposed featuring the difference between oxygen absorption and desorption rates on the palladium catalysts.

The relationship between ethanol and iso-butanol fuel concentrations and vehicle particulate matter emissions was investigated. This study utilized a gasoline direct injection (GDI) flexible fuel vehicle (FFV) with wall-guided fueling system tested with four fuels, including E10, E51, E83, and an iso-butanol blend at a proportion of 55% by volume. Emission measurements were conducted over the Federal Test Procedure (FTP) driving cycle on a chassis dynamometer with an emphasis on the physical and chemical characterization of particulate matter (PM) emissions. The results indicated that the addition of higher ethanol blends and the iso-butanol blend resulted in large reductions in PM mass, soot, and total and solid particle number emissions. PM emissions for the baseline E10 fuel were characterized by a higher fraction of elemental carbon (EC), whereas the PM emissions for the higher ethanol blends were more organic carbon (OC) in nature.

A novel ambient dilution tunnel has been designed, tested and employed to measure the emissions from active parked regenerations of Diesel Particulate Filters (DPFs) for 2007 and 2010 certified heavy duty diesel trucks (HDDTs). The 2007 certified engine had greater regulated emissions than the 2010 certified engine. For a fully loaded 2007 DPF there was an initial period of very large mass emissions, which was then followed by very large number of small particle emissions. The Particle Size Distribution, PSD, was distributed over a large range from 10 nm to 10 μm. The parked regenerations of the 2010 DPF had a much lower initial emission pattern, but the second phase of large numbers of small particles was very similar to the 2007 DPF. The emission results during regeneration have been compared to total emissions from recent engine dynamometer testing of 2007 and 2010 DPFs, and they are much larger.

This paper presents a driver assistance system designed to minimize the effect of driver reaction time on lane and speed maintenance operations. Nearly-instantaneous correcting actions are provided through a hierarchical arrangement of behaviors, by avoiding the time lag associated with deliberative or planning steps found in many control algorithms. Concepts originating in the field of robotics, including artificial potential fields and behavior-based systems, are interpreted for application to automotive control, where vehicle dynamics places considerable practical constraints on implementation. Ideas found in the study of emergent behavior in nature provide continuous, non-stepwise control signals, suitable for additive corrective inputs at highway velocities. This approach is effective for a substantial subset of road automobiles operating over a variety of speeds.

Plug-in hybrid electric vehicles (PHVs) consume both fossil fuel and grid electricity, which imposes emission testing challenges on the current constant volume sampler (CVS) test method. One reason is that in the charge-depleting cycle, PHVs having all-electric range operate the engine for a small portion of the traction energy need, causing the CVS to overdilute the exhaust gas. The other reason is that the dilution factor (DF) in the EPA calculation has an error caused by ignoring the CO₂ concentration in ambient air. This paper evaluates these challenges by testing a Toyota PHV on the industry standard CVS system combined with additional continuous sampling methodology for continuous diluents, smooth approach orifice (SAO) measurement for ambient air flow, and fuel flow meter (FFM) measurement for fuel consumption. The current EPA DF can produce an error resulting in higher mass calculation.

Considerations follow [1] on the development of the carbon/epoxy body of the Lamborghini Murcièlago. Laminate lay-up and material selection for stiffness criteria are reviewed. Engineering solutions for tooling operations in order to achieve class A surface certification are analyzed. Design for environmental aging is also discussed and accelerated degradation testing methods are described. Finally, the program that lead to the adoption of hybrid adhesive bonding as sole method of joining the composite body components to the tubular steel frame is reviewed.

Vehicle stability augmentation has been refined over many years, and currently there are commercial systems that control right/left braking and throttle to create vehicles that remain controlled when road conditions are very poor. These systems typically use yaw rate and lateral acceleration in their control philosophy. The tire/road friction coefficient, μ, has a significant role in vehicle longitudinal and lateral control, and there has been associated efforts to measure or estimate the road surface condition to provide additional information for the stability augmentation system. In this paper, a differential braking control strategy using yaw rate feedback, coupled with μ feedforward is introduced for a vehicle cornering on different μ roads. A nonlinear 4-wheel car model is developed. A desired yaw rate is calculated from the reference model based on the driver steering input.

The potential for improving the efficiency of a heavy duty turbocharged diesel engine by closed loop Air-Fuel Ratio (AFR) management has been evaluated. Testing conducted on a 12 liter diesel engine, and subsequent data evaluation, has established the feasibility of controlling the performance through electronic control of air management hardware. Furthermore, the feasibility of using direct in-cylinder pressure measurement for control feedback has been established. A compact and robust fiber optics sensor for measuring real time in-cylinder pressure has been demonstrated on a test engine. A preferred method for reducing the cylinder pressure data for control feedback has been established for continued development.

The study aims at analyzing the tool utilization by using a real-time machining simulation and investigating the behavior of the parameters which affect the tool wear based on the results of the analysis. In this study, the method of calculation of parameters which are necessary to predict the tool wear by using Z-map based machining simulation is developed. Furthermore, the possibility of estimating the tool wear from the results of the simulation was also examined by performing the real cutting experiments.

A microhygrometer has been developed at JPL's Microdevices Laboratory based on the principle of dewpoint/frostpoint detection. The surface acoustic wave device used in this instrument is approximately two orders of magnitude more sensitive to condensation than the optical sensor used in chilled-mirror hygrometers. In tests in the laboratory and on the NASA DC8, the SAW hygrometer has demonstrated more than an order of magnitude faster response than commercial chilled-mirror hygrometers, while showing comparable accuracy under steady-state conditions. Current development efforts are directed toward miniaturization and optimization of the microhygrometer electronics for flight validation experiments on a small radiosonde balloon.

The Variable Dynamic Testbed Vehicle (VDTV) concept has been proposed as a tool to evaluate collision avoidance systems and to perform driving-related human factors research. The goal of this study is to analytically investigate to what extent a VDTV with adjustable front and rear anti-roll bar stiffnesses, programmable damping rates, and four-wheel-steering can emulate the lateral dynamics of a broad range of passenger vehicles. Using a selected compact-sized automobile as a baseline, our study indicated this baseline vehicle can be controlled to emulate the lateral response characteristics (including the vehicle's understeer coefficient and the 90% lateral acceleration rise time in a J-turn maneuver) of a fleet of production vehicles, from low to high lateral acceleration conditions.

This paper is written to provide information on the fuel efficiency, emissions and energy cost of vehicles ranging from a pure electric (ZEV) to gasoline hybrid vehicles with electric range varying from 30 mi (50km) to 100 mi (160km). The Federal government s PNGV and CARB s ZEV have different goals, this paper explores some possibilities for hybrid-electric vehicle designs to meet both goals with existing technologies and batteries. The SAE/CARB testing procedures for determining energy and emission performance for EV and HEV and CARB s HEV ruling for ZEV credit are also critically evaluated. This paper intends to clarify some confusion over the comparison, discussion and design of electric- hybrid- and conventional- vehicles as well.