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Abstract A multiple output dynamically adjustable capacity system (MODACS) is developed to provide multiple voltage output levels while supporting varying power loads by switching multiple battery strings between serial and parallel connections. Each module of the system can service either a low voltage bus by placing its strings in parallel or a high voltage bus with its strings in series. Since MODACS contains several such modules, it can produce multiple voltages simultaneously. By switching which strings and modules service the different output rails and by varying the connection strategy over time, the system can balance the states of charge (SOC) of the strings and modules. A model predictive control (MPC) algorithm is formulated to accomplish this balancing. MODACS operates in various power modes, each of which imposes unique constraints on switching between configurations.

Abstract This article investigates the performance of a low-cost throttle-by-wire-system (TbWS) for two-wheeler applications. Mopeds/scooters are still restricted as environmentally harmful. TbWSs can contribute to environmental protection by replacing conventional restrictors. Its consisting of an anisotropic magnetoresistance (AMR) throttle position sensor and a position-controlled stepper motor-driven throttle valve actuator. The decentralized throttle position sensor is operating contactless and acquires redundant data. Throttle valve actuation is realized through a position-controlled stepper motor, sensing its position feedback by Hall effect. Using a PI controller, the stepper motor position is precisely set. Both units transmit and receive data by a CAN bus. Furthermore, fail-safe functions, plausibility checks, calibration algorithms, and energy-saving modes have been implemented.

Abstract In autonomous technology, uncrewed aircraft systems have already become the preferred platform for the research and development of flight control systems. Although they are subjected to following and satisfying complicated scenarios of control stations, this high dependency on a specific control framework limits them in their application process and reduces the flight self-organizing network. In this article, we present a developed multilayer control system protocol with the additional supportive manned aircraft layer (Tender). The novelty of the introduced model is that uncrewed aircraft systems are monitored and navigated by the tender, and then based on the suggested scheme, data flows are controlled and transferred across the network by the developed cloud–robotics approach in the ground station layer.

Abstract The electrically interconnected suspension (EIS) is a novel suspension system that has gained attention due to its potential to improve vehicle vibration control. This article provides a comprehensive review of EIS and related technologies. It starts with an overview of the research on hydraulic interconnected suspension (HIS) and its limitations. Then, it discusses the development of the electromagnetic suspension (EMS) and its advantages in adjusting mechanical characteristics. The article focuses on the electrical network and decoupling control characteristics of EIS, demonstrating the principle of synchronous decoupling control of multiple vibration modes. A comparison of the structure and control characteristics of EIS and HIS highlights the advantages of EIS in vehicle vibration control.

Abstract The mass trim mechanism (MTM) is used to precisely trim the mass characteristics of satellite in orbit and ensure that the satellite can provide high-precision orientation and orbit control and part of the payload can work normally. In order to ensure high-precision trim and light miniaturization, the mass trim scheme of the satellite and the MTM are designed, and the mass block moving range of the mechanism is ±145 mm. The adjusting scheme, system composition, and working principle are introduced particularly, and the screw-guide mechanism is proposed to realize the trim function. The position precision can satisfy the requirement of the design index by the theoretical calculation to get the precision of the trim mechanism. The data before and after the environmental experiments indicate that the displacement error is less than 0.06 mm and the movement parallelism of the mass block is less than 0.04 mm, which meets the requirement for use.

Abstract Autonomous driving faces the difficulty of securing the lowest possible software execution times to allow a safe and reliable application. One critical variable for autonomous vehicles is the latency from the detection of obstacles to the final actuation response of the vehicle, especially in the case of high-speed driving. A prerequisite for autonomy software is that it enables low execution times to achieve superhuman reaction times. This article presents an in-depth analysis of a full self-driving software stack for autonomous racing. A modular software stack especially developed for high-speed autonomous driving is used and the latency of the software is analyzed in four main autonomy modules: perception, prediction, planning, and control. With the help of a trace point measurement method, it is possible to investigate the end-to-end latency and runtimes of the individual modules.

Abstract The engineering of vehicular systems is becoming increasingly difficult, mainly due to the ongoing integration of cyber-physical systems (CPS) aiming to automate difficult tasks or provide additional features to drivers. This automation potential leads to increasing complexity when engineering the vehicle itself or its subcomponents. In particular the development of a future-oriented kind of mobility, namely, connected autonomous vehicles (CAVs), is accompanied by new challenges, leading back to the different domains to be considered. To cope with this complexity and enable the mutual engineering of vehicular embedded systems, the Software Platform Embedded Systems (SPES) framework provides viewpoints and hierarchy layers in the shape of a matrix. However, to address all domains considered during the development of CAVs, the SPES methodology lacks specifications of how to model such vehicles across multiple domains, which impede its utilization in actual industrial projects.

Abstract This article addresses the architecture development for a commercial vehicle fuel cell electric powertrain by establishing a clear multi-step formalized workflow that employs a unique technoeconomic solution for architecture selection. The power capability of the fuel cell, the energy capacity and chemistry of the electrical energy storage (battery), the DC-DC converter (including the input current rating and isolation resistance requirements), the traction drive solution, the on-board hydrogen storage solution, and the real-time power-split management of the fuel cell and the battery are all considered and developed in this effort. The methods were used to select architecture for Class 8 urban, regional, and line haul applications. When compared to traditional load-following power-split controllers, an energy management power-split controller can increase system energy efficiency by up to 19.5%.

Abstract Safety is always a crucial aspect of developing autonomous systems, and the motivation behind this project comes from the need to address the traffic crashes occurring globally on a daily basis. The present work studies the coexistence of the novel rule-based behavioral planning framework with the five key advanced driver assistance system (ADAS) features as proposed in this article to fulfill the safety requirements and enhance the comfort of the driver/passengers to achieve a receding-horizon autopilot. This architecture utilizes data from the sensor fusion and the prediction module for the prediction time horizon of 2 s iteratively, which is continuously moving forward (hence, the receding horizon), and helps the behavior planner understand the intent of other vehicles on the road in advance.

Abstract Vehicular communications face unique security issues in wireless communications. While new vehicles are equipped with a large set of communication technologies, product life cycles are long and software updates are not widespread. The result is a host of outdated and unpatched technologies being used on the street. This has especially severe security impacts because autonomous vehicles are pushing into the market, which will rely, at least partly, on the integrity of the provided information. We provide an overview of the currently deployed communication systems and their security weaknesses and features to collect and compare widely used security mechanisms. In this survey, we focus on technologies that work in an ad hoc manner. This includes Long-Term Evolution mode 4 (LTE-PC5), Wireless Access in Vehicular Environments (WAVE), Intelligent Transportation Systems at 5 Gigahertz (ITS-G5), and Bluetooth.

Abstract Electrification of vehicles can improve energy efficiency and reduce emissions in vehicle operations. Studies have focused on designing powertrains of several topologies, including serial, parallel, and power-split hybrid powertrains. In this study, a design and control co-optimization is demonstrated for a novel mixed-powertrain architecture. The component sizes of the mixed powertrain are optimized to minimize the fuel and component costs. Nested optimization is applied with a surrogate integrated operation and control model that evaluates powertrain performance in the inner loop. The surrogate model is trained to capture the powertrain performance under a near-optimal power management approach, namely, the equivalent consumption minimization strategy (ECMS). Using sequential quadratic programming, optimal results are obtained and verified using a high-fidelity powertrain model which is equipped with ECMS control.

Abstract Super-knock is a phenomenon triggered by pre-ignition and has limited the design envelope of internal combustion engines (ICEs) in terms of power density. This poses a huge challenge for the automotive industry where engine sizes have been continuously decreasing due to the demand for weight savings and integration with electrified powertrains. Such downsized engines typically require increased boost pressure, availing conditions conducive to pre-ignition, which in turn may trigger super-knock. Traditionally, this and other forms of knock have been managed by way of a “detection and mitigation” approach in place of “perdition and avoidance” due to an evolving understanding of corresponding combustion dynamics, as well as the incapability of emerging real-time computational methods to perform and actuate over the timescale required.

Abstract Vehicle to Everything (V2X) allows vehicles, pedestrians, and infrastructure to share information for the purpose of preventing accidents, enhancing road safety, and improving the efficiency and energy consumption of transportation. Although V2X messages are authenticated, their content is not validated. Sensor errors or adversarial attacks can cause messages to be perturbed and, therefore, increase the likelihood of traffic jams, compromise the decision process of other vehicles, or provoke fatal crashes. In this article, we introduce V2X Core Anomaly Detection System (VCADS), a system based on the theory presented in [1] and built for the fields provided in the periodic messages shared across vehicles (i.e., Basic Safety Messages, BSMs). VCADS uses physics-based models to constrain the values in each field and detect anomalies by finding the numerical difference between a field and independent derivations of the same field.

Abstract This article presents a survey on active safety control of X-by-wire electric vehicles. The steer-by-wire (SBW) system, brake-by-wire (BBW) system, and electric drive system are three critical techniques for X-by-wire electric vehicles. As to the three systems, the structure comparison and performance analysis of existing products and prototypes are conducted. Then two kinds of X-by-wire chassis configuration, i.e., the centralized type and the distributed type, are introduced. For active safety control, various control models are summarized, including vehicle dynamics model, single-track model, path tracking model, and wheel dynamics model. Based on the proposed model, different active safety control algorithms are introduced involving longitudinal dynamics control, handling stability control, rollover prevention control, path tracking control, and active fault-tolerant control.

Letter from the Special Issue Editors

Abstract We demonstrate a virtual proof-of-concept design and experiment for harvesting energy enabling economic and environment-friendly aircraft by recycling forces for power conversion. The harvesting uses piezoelectric materials for extracting energy from the impact at the touchdown during the landing of an aircraft and direct current (DC) generators powered by the rotational motion of the aircraft wheels during taxiing. The design begins with a multidomain model comprising multibody dynamics, mathematical descriptions, abstract behavioral blocks, and programmed code. Piezoelectric harvesting explores six types of materials consisting of ring and disk pad geometries. Both geometries are typical configurations in suspension systems. Recent advances have shown the potential of getting higher voltage out of new materials properties. Our objective is to determine the useful impact force during a touchdown on the pads and a pad type that maximizes the power transfer.

Abstract Formula Student Driverless (FSD) challenges engineering students to develop autonomous single-seater race cars in a quest to bring about more graduates who are well prepared to solve the real-world problems associated with autonomous driving. In this article, we present the software stack of KA-RaceIng’s entry to the 2019 competitions. We cover the essential modules of the system, including perception, localization, mapping, motion planning, and control. Furthermore, development methods are outlined, and an overview of the system architecture is given. We conclude by presenting selected runtime measurements, data logs, and competition results to provide an insight into the performance of the final prototype.

Abstract This research develops a hierarchical control strategy to improve the stability of multi-axle electric vehicles with in-wheel motors while driving at high speed or on low adhesion-coefficient roads. The yaw rate and sideslip angle are chosen as the control parameters, and the direct yaw-moment control (DYC) method is employed to ensure the yaw stability of the vehicle. On the basis of this methodology, a hierarchical yaw stability control architecture that consists of a state reference layer, a desired moment calculation layer, a longitudinal force calculation layer, and a torque distribution layer is proposed. The ideal vehicle steering state is deduced by the state reference layer according to a linear two-degree-of-freedom (2-DOF) vehicle dynamics model.

Abstract The innovations of vehicle connectivity have been increasing dramatically to enhance the safety and user experience of driving, while the rising numbers of interfaces to the external world also bring security threats to vehicles. Many security countermeasures have been proposed and discussed to protect the systems and services against attacks. To provide an overview of the current states in this research field, we conducted a systematic mapping study (SMS) on the topic area “security countermeasures of in-vehicle communication systems.” A total of 279 papers are identified based on the defined study identification strategy and criteria. We discussed four research questions (RQs) related to the security countermeasures, validation methods, publication patterns, and research trends and gaps based on the extracted and classified data. Finally, we evaluated the validity threats and the whole mapping process.

Abstract Closed field testing of Connected and Automated Vehicles (CAV) is an essential pillar for verifying the functionality and performance of CAV and promoting its large-scale deployment. Recently, many closed test fields in the world have been newly built or rebuilt for testing CAV such as M-City in USA and AstaZero in Sweden. However, few construction methods, standards, and specifications of closed test fields for testing CAV were reported with details. We propose the construction practice of the Closed Connected and Automated Vehicles Test Field (CAVTest) of Chang’an University in China. The CAVTest has a multilayer architecture, from down to the top, which consists of an application scenario layer, a perception and a physical communication layer, a network link layer, and a management service layer, respectively.