Control technology for engines and/or powertrains is becoming increasingly important for achieving higher energy efficiency and lower CO2 emissions in the real world in terms of the carbon neutrality of automobiles. CO2 emissions can be reduced using advanced combustion technologies and/or powertrain systems including hybrid powertrains. Such advanced combustion technologies show low robustness to changes in operation conditions, and advanced powertrain systems are difficult to optimize for complicated systems and uncertainty in the real road driving. Therefore, control technology is essential for taking full advantage of such hardware capabilities. Furthermore, the effective use of various information that is currently available, such as that on traffic signals, maps, and other cars, could lead to further reductions in CO2 emissions and energy consumption. This review summarizes the research on control technology, especially for advanced combustion and powertrain systems, and discusses the role of powertrain control and its future prospects.

抄録全体を表示

Modern in-vehicle networks may contain tens of Electronic Control Units (ECUs) connected over several Controller Area Network (CAN) buses. To protect vehicles from cyberattacks, researchers have proposed various security countermeasures, including intrusion detection systems (IDS). Because real clock sources are imperfect, ECUs transmit messages with a period slightly different from the ideal period. This difference is referred to as clock skew, and previous research suggests that IDS may detect anomalies when they observe that an ECU transmits periodic CAN messages with a different clock skew than expected. We argue that previously proposed approaches rely on an incomplete model and may yield inaccurate results when applied to a real vehicle. This is problematic for automotive technologies, which must be reliably deployed in millions of safety-critical systems. We propose an improved model for the fluctuations of CAN message timestamps and apply it to a real vehicle, where we are able to improve the accuracy of ECU clock skew estimations.

抄録全体を表示

This work provides a study of methods for the automated derivation of control strategies for over-actuated systems. For this purpose, Reinforcement Learning (RL) and Model Predictive Control (MPC) approximating the solution of the Optimal Control Problem (OCP) are compared using the example of an over-actuated vehicle model executing an ISO Double Lane Change (DLC). This exemplary driving maneuver is chosen due to its critical vehicle dynamics for the comparison of algorithms in terms of control performance and possible automation within a design space exploration framework. The algorithms show reasonable control results for the goal of this study, although there are differences in terms of driving stability. While Model Predictive Control first requires the optimization of the trajectory, which should then be optimally tracked, RL may combine both in one step. In addition, manual effort required to adapt the OCP problem to new design variants for solving it with RL and MPC is evaluated and assessed with respect to its automation. As a result of this study, an Actor-Critic Reinforcement Learning method is recommended for the automated derivation of control strategies in the context of a design space exploration.

抄録全体を表示

The rapid introduction of automated driving functionalities in vehicles, has forced the necessity to systematically organize the methodologies for traffic safety assessment. Their safety impacts depend on many factors: human, vehicle, traffic, size of implementation. Modelling and simulations on the driver up to the societal level, play a vital role in assessment. This paper discusses the need, as well as an approach, to develop a multi-level safety assessment framework, facilitating the mitigation of risks. Via a research-driven format, this paper provides practitioners with a strategy to effectively perform safety assessment, offering practical, stepwise guidelines regarding the relevant models and tools.

抄録全体を表示

This study addresses an issue arising during requests to intervene, usually focused on the direct shift of control from the system to an unprepared driver. We explore an approach based on the concept of adaptive automation. The approach is utilized to establish a strategy that the automated driving system can modulate between different driving states (Level 0 (L0) to Level 3 (L3) driving automation) based on traffic situations. Furthermore, we aim to design Human-Machine Interface (HMI) instructions that align with two design perspectives: system-centered (Implicit) and human-centered (Explicit). These HMI instructions critical to the strategy implemented are intended to sustain awareness on driver roles and decrease inappropriate driver responses during transitions. In the experiment, we utilized two approaches (adaptive control transition strategy and fixed control transition strategy) and two HMI designs. The experiment with a driving simulator was conducted with 60 drivers. The research questions explored include the influence of HMI design on drivers’ awareness during shifts from L3 to L2/L1. Also, we examine how different combinations of a strategy and HMI design affect reaction times from L3 to L0 scenarios. Compared to Implicit-HMI, the use of Explicit-HMI did not lead to inappropriate actions associated with their driving roles. This indicates that Explicit-HMI facilitates accurate response to state changes during the implementation of the adaptive approach. In terms of the comparison of the combinations, it is found that the adaptive approach provides initial guidance for drivers to monitor the environment, thereby providing earlier reaction time for the transition to manual.

抄録全体を表示

With the increasing number of vehicles equipped with conditional driving automation entering the market, it has become important to address the topic of improving driver takeover performance. This study focuses on designing the request to intervene (RtI) under conditional driving automation. We investigated takeover guidance and surrounding traffic information in the RtI influent takeover performance by conducting a driving simulator experiment. 32 participants were divided into four different groups based on the RtI design. The results show that adding surrounding traffic information to the RtI improves the safety of takeover performance. However, the combination of surrounding traffic information and takeover guidance impairs the takeover performance quality. Although all types of additional content (takeover guidance, surrounding traffic information, combination of takeover guidance, and surrounding traffic information) did not increase the participants’ workload during takeover, the participants gave a higher rating to the usability of the surrounding traffic information than the combination. This study demonstrates the importance of providing surrounding traffic information in RtI and the effectiveness of the system usability scale (SUS) in evaluating RtI designs.

抄録全体を表示

A new two-phase mass transfer Computational Fluid Dynamics (CFD) method is developed using a meshfree collocation approach, or Generalized Finite Difference Method (GFDM), to resolve the evaporation phenomenon at the waterair interface since it is essential to estimate the water dry-out-time for corrosion protection schemes on automotive components. Thereby, the volume-volume-coupling to couple the phases – air and water – is used in order to keep a stable phase interface. At the interface, it is assumed that the main driving force of the liquid mass transfer into vapor is diffusion driven by the vapor concentration gradient. The automatized adaptive refinement based on the humidity- and velocity-gradient enabling the automation of the whole process is also developed. The newly developed method is validated with one simple and actual vehicle geometries. In vehicle geometry case, the total-dry-out times of an accumulated water source at the corner of a sunroof are measured. In order to extend the time scale of the simulation to real, the water reduction rate at the free surface is artificially accelerated once the evaporation rates are quasi stabilized. The validation results are promising, and the method could be extended into further complex vehicle applications.

抄録全体を表示