With the continuous development of assisted driving technology, the autonomous emergency braking (AEB) system has emerged as a critical innovation in preventing collisions and improving vehicular safety. In this paper, to test the performance of the AEB system efficiently and reliably in real-world driving scenarios, four typical test scenarios for the AEB system were constructed, and five comprehensive performance evaluation indices, including braking parking distance, braking deceleration, collision warning time, speed variation, and accident collision avoidance rate, were proposed for the first time. Subsequently, the Comprehensive Performance Evaluation Index Model (CPEIM) for the AEB system and scoring rules for typical test scenarios were established, which were applied to analyze data obtained from road testing, thereby enabling comprehensive testing and evaluation for AEB system performance. The results showed that the Tesla Model Y and Volvo S90 scored 1.8857 and 2.0433, respectively. Under conditions of dry pavement, across a range of test scenarios, the AEB system of both the Tesla Model Y and Volvo S90 were capable of averting collisions at speeds not exceeding 35 km/h and 45 km/h, respectively.
Lithium-ion batteries (LIBs) with high power, high capacity, and support for fast charging are increasingly favored by consumers. As a commercial electrode material for power batteries, LiFePO4 was limited from further wide application due to its low conductivity and lithium-ion diffusion rate. The development of advanced architectures integrating rational conductive networks with optimized ion transport pathways represents a critical frontier in optimizing the performance of cathode materials. In this paper, a novel self-supporting cathode material (designated as LFP@LVP-CES) was synthesized through an integrated coaxial electrospinning and controlled pyrolysis strategy. This methodology directly converts LiFePO4, Li3V2(PO4)3, and polyacrylonitrile (PAN)) into flexible, binder-free cathodes with a hierarchical structural organization. The 3D carbon nanofiber (CNF) matrix synergistically integrates LiFePO4 (Li/Fe/POx) and Li3V2(PO4)3 (Li/V/POx) nanoparticles, where CNFs act as a conductive scaffold to enhance electron transport, while the POx polyanionic frameworks stabilize Li+ diffusion pathways. Morphological characterizations (SEM and TEM) revealed a 3D cross-connected carbon nanofiber matrix (diameter: 250 ± 50 nm) uniformly embedded with active material particles. Electrochemical evaluations demonstrated that the LFP@LVP-CES cathode delivers an initial specific capacity of 165 mAh·g−1 at 0.1 C, maintaining 80 mAh·g−1 at 5 C. Notably, the material exhibited exceptional rate capability and cycling stability, demonstrating a 96% capacity recovery after high-rate cycling upon returning to 0.1 C, along with 97% capacity retention over 200 cycles at 1 C. Detailed kinetic analysis through EIS revealed significantly reduced Rct and increased Li+ diffusion. This superior electrochemical performance can be attributed to the synergistic effects between the 3D conductive network architecture and dual active materials. Compared with traditional coating processes and high-temperature calcination, the preparation of controllable electrospinning and low-temperature pyrolysis to some extent avoid the introduction of harmful substances and reduce raw material consumption and carbon emissions. This original integration strategy establishes a paradigm for designing freestanding electrode architectures through 3D structural design combined with a bimodal active material, providing critical insights for next-generation energy storage systems.
In order to accurately simulate the actual road driving resistance of four-wheel drive motor vehicles based on the chassis dynamometer and efficiently test the vehicle performance, it is necessary to analyze the influencing factors of the additional loss resistance and the loading resistance of the chassis dynamometer bench system. In this paper, the effects of the drum speed, the sampling speed interval, and basic inertia on the test results of the additional loss resistance are tested and analyzed based on the self-developed chassis dynamometer of a four-wheel drive motor vehicle. The static and dynamic components of the additional loss resistance are defined by linear regression through ordinary least squares, and the additional loss resistance of the four-axis eight-drum chassis dynamometer and mainstream chassis dynamometer system for four-wheel drive motor vehicles are compared. In addition, the effects of the dynamometer type and the control strategy on the loading resistance are discussed, and the transient condition, steady-state condition, and overall operating condition deviation coefficient of loading force are defined, according to which the advantages and disadvantages of the control strategy of the chassis dynamometer system for four-wheel drive motor vehicles are evaluated. The analysis of the influencing factors and laws of the resistance of the four-wheel drive motor vehicle chassis dynamometer bench system can provide a reference basis for accurately simulating the resistance of vehicle road driving based on the bench testing.
In the field of active safety technology for intelligent connected vehicles (ICVs), the reliability and safety of the Automatic Emergency Braking (AEB) system is recognized as critical to driving safety. However, existing evaluation methods have been constrained by the inadequacy of static weight assessments in adapting to diverse driving conditions, as well as by the disconnect between conventional evaluation frameworks and experimental validation. To address these limitations, a comprehensive Vehicle-in-the-Loop (VIL) evaluation system based on the dynamic weight analytic hierarchy process (DWAHP) was proposed in this study. A two-tier dynamic weighting architecture was established. At the criterion level, a bivariate variable–weight function, incorporating the vehicle speed and road surface adhesion coefficient, was developed to enable the dynamic coupling modeling of road environment parameters. At the scheme level, a five-dimensional indicator system—integrating braking distance, collision speed, and other key metrics—was constructed to support an adaptive evaluation model under multi-condition scenarios. By establishing a dynamic mapping between weight functions and driving condition parameters, the DWAHP methodology effectively overcame the limitations associated with fixed-weight mechanisms in varying operating conditions. Based on this framework, a dedicated AEB system performance test platform was designed and developed. Validation was conducted using both VIL simulations and real-world road tests, with a Volvo S90L as the test vehicle. The experimental results demonstrated high consistency between VIL and real-world road evaluations across three dimensions: safety (deviation: 0.1833/9.5%), reliability (deviation: 0.2478/13.1%), and riding comfort (deviation: 0.05/2.7%), with an overall comprehensive score deviation of 0.0707 (relative deviation: 0.51%). This study not only verified the technical advantages of the dynamic weight model in adapting to complex driving environments and analyzing multi-parameter coupling effects but also established a systematic methodological framework for evaluating AEB system performance via VIL. The findings provide a robust foundation for the testing and assessment of AEB system, offer a structured approach to advancing the performance evaluation of advanced driver assistance systems (ADASs), facilitate the safe and reliable validation of ICVs’ commercial applications, and ultimately contribute to enhancing road traffic safety.
Proton exchange membrane fuel cells (PEMFCs) have been widely studied as an efficient and environmentally friendly energy conversion technology in recent years. However, the high cost, easy poisoning and complex synthesis methods of noble metal catalysts have hindered their commercialization. Therefore, in this paper, a non-noble metal composite catalyst CuFeCo/C for the oxygen reduction reaction (ORR) was prepared by using a facile liquid-phase reduction method. The ORR kinetic performance of CuFeCo/C was evaluated by cyclic voltammetry (CV), linear sweep voltammetry (LSV) and rotating ring-disk electrode (RRDE) tests. The results show that the oxygen reduction peak of CuFeCo/C appears at about 0.64 V, the half-wave potential is about 0.73 V, the limiting current density is about −16.51 A·m−2, and the Tafel slope is about −0.08. The 10,800 s chronoamperometry test shows that the catalyst has a very good long-term cycle stability. This indicates that the CuFeCo/C composite catalyst has strong stability, good conductivity and ORR catalytic activity under alkaline conditions, which can promote the large-scale commercial application of PEMFCs.