Automotive Emissions

This paper presents some of the issues that complicate the statistical analysis of real-world vehicle emissions and the effectiveness of emissions control programs. The following issues are discussed: 1) inter-and intra-vehicle emissions variability, 2) skewness of the distribution of emissions from inuse vehicles, 3) the difficulty of obtaining statistically representative vehicle samples, 4) the influence of repeat testing on only a subset of the vehicle fleet, and 5) differences among common test methods and pollutant measurement devices. The relevance of these issues is discussed in light of three regulatory purposes: testing the compliance of in-use vehicles with certification standards, evaluating the effectiveness of vehicle inspection and maintenance programs, and estimating emissions inventories for air quality modeling and compliance planning. A brief history and description of common vehicle emissions tests is also provided.

A control intended data driven B-spline model for NO x and soot emitted was developed and validated for the 5-cylinder, 2.4-litre Volvo passenger car diesel engine in earlier work. This work extends on the same methodology with some improvements on the model structure for more intuitive calibration and is also developed for the new generation 4-cylinder, 2litre Volvo passenger car diesel engine. The earlier model was validated using steady state engine measurements and proposed that the model would hold good for transient engine operation. The hypothesis formulated is that a transient engine emission model can be envisioned as a sequence of multi-step steady state engine operation points with minor deviations from the nominal engine operating conditions. The theory is supported by the literature that provides more insight into the transient operation. This idea is carried out in the current work using engine test cell measurements validated for a NEDC as well as a normal road drive cycle that depicts a more transient driving behaviour in comparison to the standard emission driving cycles. Nearly 4600 engine operating points with steady state measurement including nominal and deviant conditions have been used in the development of the model. The ability of the data driven approach to mimic the engine emission generation characteristics during the engine transient operation is analysed and its superior performance in comparison to the Nominal model and the Regression model is demonstrated.

The Trump Administration has been rolling back environmental and other regulations at a rapid rate. Each time, they are called upon to interpret their authorizing statutes. As they reverse previous administrations' regulations, how do their new interpretations address the statutes' fundamental objectives? In this Essay, I assess one part of the National Highway Traffic Safety Administration (NHTSA)'s and Environmental Protection Agency (EPA)'s rollback of clean car standards: a regulation stating that the Energy Policy and Conservation Act (EPCA) preempts California's trailblazing controls on vehicles' greenhouse gas emissions. I argue that the agency preemption analysis gave insufficient attention to Congress's explicit statutory purposes, largely ignoring EPCA's energy-conservation goals and the Clean Air Act (CAA)'s and California's environmental goals. This lack of fidelity to the statutes' fundamental purposes and values has significant consequences. From a systemic perspective, unmoored from the statutes' core purposes, the agency is freely pursuing an antiregulatory agenda that runs contrary to congressional intent. From an environmental standpoint, the rule compromises the nation's capacity to curb greenhouse gas (GHG) emissions from and promote essential technological innovation in the transportation sector, the nation's largest GHG emissions source.

The air quality in metropolitan areas of Russia and Italy, although with different distribution and intensity, raises similar concerns for the respective public authorities about vehicle emissions, as well as about the stagnation of toxic pollutants in urban areas. This article discusses some typical situations in both these countries. In order to obtain suitable solutions to diminish this form of impact, different tools that are based on different approaches can be proposed. It is necessary to consider both the practical possibility of application and the cost-benefit balance that takes into account the realization cost and industrial system transformation on one side, and the results in terms of air quality improvement on the other. The different instruments (technological intervention on engines, chemical modification of fuels, mobility and road infrastructural planning) are presented for the considered countries, and also in more developed European and American areas, with a concentrated interest in areas of applicability, costs and obtained results. The externality of this form of pollution is presented and discussed, and the aspect of limitation of impact and consequent external costs is evaluated in comparison with monetary and infrastructural costs for emissive system modification.

The air quality in metropolitan areas of Russia and Italy, although with different distribution and intensity, raises similar concerns for the respective public authorities about vehicle emissions, as well as about the stagnation of toxic pollutants in urban areas. This article discusses some typical situations in both these countries. In order to obtain suitable solutions to diminish this form of impact, different tools that are based on different approaches can be proposed. It is necessary to consider both the practical possibility of application and the cost-benefit balance that takes into account the realization cost and industrial system transformation on one side, and the results in terms of air quality improvement on the other. The different instruments (technological intervention on engines, chemical modification of fuels, mobility and road infrastructural planning) are presented for the considered countries, and also in more developed European and American areas, with a concentrated interest in areas of applicability, costs and obtained results. The externality of this form of pollution is presented and discussed, and the aspect of limitation of impact and consequent external costs is evaluated in comparison with monetary and infrastructural costs for emissive system modification.

In order to optimize the performance of a diesel engine subject to legislative constraints on pollutant emissions, it is necessary to improve their design, and to identify how design parameters affect engine behaviours. One specificity of this work is that it does not exist a physical model of engine behaviour under all possible operational conditions. A powerful strategy for engine modeling is to build a fast emulator based on carefully chosen observations, made according to an experimental design. In this paper, two Kriging models are considered. One is based on a geostatistical approach and the other corresponds to a Gaussian process metamodel approach. Our aim is to show that the use of each of these methods does not lead to the same results, particularly when "atypical" points are present in our database. In a more precise way, the statistical approach allows us to obtain a good quality modeling even if atypical data are present, while this situation leads to a bad quality of the modeling by the geostatistical approach. This behaviour takes a fundamental importance for the problem of the pollutant emissions, because the analysis of these atypical data, which are rarely erroneous data, can supply precious information for the engine tuning in the design stage.

The European laws lead to the increase of emission constraints. In order to take into account these constraints, automotive constructors are obliged to create more and more complex systems. This paper presents two stage approaches for the prediction of NOx (nitrogen oxide) emissions, which are based on an ordinary Kriging method. In the first stage, a reduction of data will take place by selecting signals with correlations studies and by using a fast Fourier transformation. In the second stage, the Kriging method is used to solve the problem of the estimation of NOx emissions under given conditions. Numerical results are presented and compared to highlight the effectiveness of the proposed methods. 2 ORDINARY KRIGING TECHNIQUES Kriging methods is used frequently for spatial interpolation of soil properties. Kriging is a linear least squares estimation algorithm. It is a tool for interpo-260

In order to optimize the performance of a diesel engine subject to legislative constraints on pollutant emissions, it is necessary to improve their design, and to identify how design parameters affect engine behaviours. One specificity of this work is that it does not exist a physical model of engine behaviour under all possible operational conditions. A powerful strategy for engine modeling is to build a fast emulator based on carefully chosen observations, made according to an experimental design. In this paper, two Kriging models are considered. One is based on a geostatistical approach and the other corresponds to a Gaussian process metamodel approach. Our aim is to show that the use of each of these methods does not lead to the same results, particularly when "atypical" points are present in our database. In a more precise way, the statistical approach allows us to obtain a good quality modeling even if atypical data are present, while this situation leads to a bad quality of the modeling by the geostatistical approach. This behaviour takes a fundamental importance for the problem of the pollutant emissions, because the analysis of these atypical data, which are rarely erroneous data, can supply precious information for the engine tuning in the design stage.

This paper presents the control of Spark Ignition (SI) Internal Combustion (IC) engine Fuel-to-Air Ratio (FAR) using an adaptive control method of time-delay systems. The objective is to maintain the in-cylinder FAR at a prescribed set point, determined primarily by the state of the Three-Way Catalyst (TWC), so that the pollutants in the exhaust are removed with the highest efficiency. The FAR controller must also reject disturbances due to canister vapor purge and inaccuracies in air charge estimation and wallwetting (WW) compensation. Two adaptive controller designs are considered. The first design is based on feedforward adaptation while the second design is based on both feedback and feedforward adaptation incorporating the recently developed Adaptive Posicast Controller (APC). Both simulation and experimental results are presented demonstrating the performance improvement by employing the APC. Modifications and improvements to the

Reducing transport emissions, in particular vehicular emissions, is a key element for mitigating the risks of climate change. In much of the academic and public discourse the focus has been on alternative vehicle technologies and fuels (e.g. electric cars, fuel cells and hydrogen), whereas vehicles based on internal combustion engines have been perceived as close to their development limits. This paper offers a different perspective by demonstrating the accelerated improvement processes taking place in established combustion technologies as a result of a new competition between manufacturers and technologies, encouraged both by more stringent EU legislation and new CAFE levels in the US. The short-term perspective is complemented by an analysis of future improvement potentials in internal combustion technologies, which may be realized if efficient regulation is in place. Based on a comparison of four different regulatory approaches, the paper identifies the need for a long-term technology-neutral framework with stepwise increasing stringencies, arguing that this will encourage continual innovation and diffusion in the most effective way.