Today’s vehicles already have several driver assistant systems and in the near future highly automated vehicles will also appear in road transport. Higher automation levels rely on disruptive technologies that cannot be tested and approved in the former way. To be able to guarantee future road safety also disruptive testing and validation methods are required. The complexity of the systems and the stochasticity of the potential traffic situations demand new approaches with different testing levels and approval layers. Since there are no off-the-self solutions available beyond the research the authors also participate in international activities like the Gear 2030 EU level initiative. This paper will discuss the proposed new approach for connected and automated vehicle testing methodology concluding with the technical specification results for the new Hungarian automotive proving ground.

Modern Diesel engines have complex exhaust gas recirculation (EGR) systems. Due to the high temperatures, it is a typical issue to measure EGR mass flow rates in these complex control systems. Therefore, it is expedient to estimate it. Several sensed values can help the estimation: the fresh air mass flow rate, the fuel consumption, pressures, temperatures and mass fractions in the air path system. In most of the articles, the EGR mass flow rate estimation is done by the pressures. However, gas composition based models usually would be better for control aims. In this paper, nine EGR estimation methods will be presented: an important outcome is to present the required sensor architectures and estimation challenges. The comparison will be made by measurement results both in stationary operation points and transient cycles. The estimated EGR mass flow rates will be evaluated by verification conditions. The results will prove that the intake and exhaust side oxygen sensors can give verifiable signals for EGR mass flow rate estimation. In contrast, the applied fresh air mass flow rate and the nitrogen-oxide signals are not accurate enough to provide verifiable EGR mass flow rates in every operating condition. The effects of sensor inaccuracies will also be considered.

Modern Diesel engines contain sophisticated control systems to keep their environmental impact low for sustainable road transport. One of these systems is the dual loop exhaust gas recirculation, which can change combustion properties in several ways. This article presents an engine dyno measurement based on analyzing the duel loop EGR with a medium-duty Diesel engine. Intake throttles and exhaust brakes for the highest freedom in the air-fuel ratio setting support the EGR systems. The EGR modes are compared from fuel consumption, NOx emission, and exhaust gas opacity in steady and transient operations. There are expected results, for instance, in the HP EGR’s faster reaction time or the LP EGR’s boost pressure holding property. Unexpected results are also presented. Contrary to theory, LP EGR generally provides a fuel consumption advantage in many operation points due to its higher boost pressure. Typically, HP EGR can provide lower fuel consumption at higher engine power. In the emission results, LP EGR is favourable both in NOx emission and exhaust gas opacity, whereas the intake throttle-supported HP EGR usually shows the highest emission. Besides, with high EGR rates at lower engine loads, LP EGR can realize low-temperature combustion, where both emissions decrease. No difference can be detected between the LP EGR’s support valves’ results. HP EGR was faster in the transient operation, with about half the reaction time. The results can be utilized for dual-loop EGR layout and control design.

Autonomous or highly automated road vehicles and all related technologies are under intensive research and development. Moreover, internationally a massive investment increase can be observed in the automotive industry. According to this megatrend, new automotive test tracks appear or older ones transform to be capable of testing and proving for autonomous vehicles. Therefore, the question emerges: what are the key areas for automated drive development, which must be financed in case of autonomous proving ground design? It is a real challenge to be able to make the right decisions due to a lack of numerous experiences in this field. In this research, experts of automated driving technology have been surveyed and their opinion and knowledge have been synthesized. As a strong purpose of gaining robust results, the conventional AHP has been amended by the Pareto approach to ensure that the derived weights correspond to the expert scoring intention so perfectly that it cannot be more improved. Since the non-Pareto optimal weight results might cause rank reversal in the final prioritization, the applied Pareto test guarantees that the final outcome reflects the expert evaluators' incentive. The conducted analysis has indicated that the obtained results are robust not only from the sensitivity point of view but also from the Pareto optimality approach. The proposed hierarchical decision model is therefore applicable to assist decision making for autonomous proving ground developments. The main contribution of the article, however, is to present the first reliable prioritization of the autonomous proving ground elements to extend the body of professional knowledge.

Nowadays, increasingly stricter regulations on emission reduction are inducing rapid developments in combustion science. Low-temperature combustion (LTC) is an advanced combustion technology that increases an engine’s thermal efficiency and even provides low emissions of nitrogen oxides (NO_x) and particulate matter (PM). The technology often uses early direct injections to achieve sufficient mixture homogeneity. This leads to increasing wall wetting and lower combustion efficiency. This paper introduces the Multipulse ballistic injection (MBI) method to improve combustion with early injection timings. The research was carried out in a four-cylinder medium-duty diesel engine with high-pressure exhaust gas recirculation (HP-EGR). The investigation was divided into two experiments. In the first experiment, MBI was examined without EGR, and in the second, EGR was applied to study its effects. It was found that the MBI strategy decreased wall wetting and increased homogeneity and the indicated mean effective pressure (IMEP) at early injection angles.