Passenger Vehicles Research Articles

Performance Improvement in a Vehicle Suspension System with FLQG and LQG Control Methods

This study investigates the effect of active control on a quarter-vehicle suspension system. The car suspension system was modeled using the Lagrange–Euler method. The linear quadratic Gaussian (LQG) and fuzzy linear quadratic Gaussian (FLQG) control methods were designed and used for active control to increase vehicle handling and passenger comfort, with the aim of reducing or eliminating vibrations by performing active control of passive suspension systems using these methods. The optimum values of the coefficients of the points where the membership functions of the LQG and Fuzzy LQG methods touch were obtained using the grey wolf optimization (GWO) algorithm. The success of the control performance rate of the applied methods was compared based on the passive suspension system. In addition, the obtained results were compared with each other and with other studies using the integral time-weighted absolute error (ITAE) performance criterion. The proposed control method yielded significant improvements in vehicle parameters compared with the passive suspension system. Vehicle body movement, vehicle acceleration, suspension deflection, and tire deflection improved by approximately 88.2%, 91.5%, 88%, and 89.4%, respectively. Thus, vehicle driving comfort was significantly enhanced based on the proposed system.

The Efficacy of the New Energy Vehicle Mandate Policy on Passenger Vehicle Market in China

This paper aims to assess the impact of the New Energy Vehicle (NEV) mandate policy on the passenger vehicle market in China, with a focus on its effectiveness in promoting NEV adoption. In response to global climate goals and energy security concerns, China has implemented various NEV policies, including the phase-out of direct subsidies and the introduction of the NEV mandate policy (dual-credits policy). This policy, which combines NEV credits and Corporate Average Fuel Consumption (CAFC) credits, aims not only to promote NEV adoption but also to support industrial policy objectives by helping the auto industry leapfrog traditional internal combustion engines and become globally competitive. In this study, a System Dynamics (SD) model was developed using Vensim software (10.2.2) to simulate interactions between automakers, government policies, and consumer behaviors. The results show that the NEV mandate policy significantly boosts NEV sales, with projections indicating that NEV sales will reach 15 million units by 2030, accounting for 55% of the passenger vehicle market. Additionally, the study finds that tightening NEV credits standards and increasing the NEV credit proportion requirements can further enhance market growth, with stricter measures post-2023 being crucial to achieving a 50% market share. In contrast, under a scenario where the dual-credits policy ends in 2024, the NEV market share would still grow but would fall short of the 50% target by 2030. The findings suggest that stronger policy measures will be essential to maintain long-term market momentum.

Evaluating Supply Chain Transformation of Passenger Vehicle Industry Towards Manufacturing in Bangladesh

Bangladesh is classified as a lower-middle-income economy by the World Bank, with a Gross National Income (GNI) per capita of $2,824. It is also designated as a Least Developed Country (LDC) by the United Nations, based on low income, human asset deficits, and economic vulnerability. However, in February 2021, the UN Committee for Development Policy (CDP) recommended Bangladesh for LDC graduation, recognizing its progress in income growth, human development, and economic resilience. Bangladesh, which is the second largest economy in South Asia gained independence in 1971. Nearly 54 years have passed, yet customers in the passenger vehicle segment predominantly rely on used, reconditioned cars imported from Japan. These vehicles, allowed for import up to five years after manufacture, continue to dominate the market. However, there is a growing need to shift toward locally manufactured, brand-new vehicles to advance the country's automobile sector. Establishing a domestic automobile manufacturing industry could drive employment, strengthen the local economy, and improve living standards. Thus, many prime points come into limelight like consumer behaviour, government support and infrastructural capability. This study explores the future of the automotive supply chain in Bangladesh, focusing on identifying key factors that could drive its transformation. Utilizing a hypothesis-driven research design, the study analyzes survey responses to uncover consumer preferences and emerging trends shaping the industry. The findings provide critical insights into the potential shift from a reliance on imported reconditioned vehicles to localized manufacturing, highlighting opportunities and challenges within the evolving automotive landscape of Bangladesh.

International Consensus Definition of 'Sport & Exercise' in Toddlers and Young Children, Children, and Adolescents.

The study aim was to develop an age-appropriate definition of sport and exercise in children and adolescents for use in concussion research and management. A modified Delphi methodology, with three rounds and consensus defined a priori as ≥ 80% agreement. Thirty-one participants (13 male, 18 female) from 13 countries, including clinical psychologists, epidemiologists, implementation scientists, neurologists, neuropsychologists, neurosurgeons, paediatric emergency physicians, paediatricians, physiotherapists, rehabilitation physicians, speech-language pathologists, and sports medicine physicians came to a consensus that sport-related paediatric concussion extends beyond the sporting arena, and includes the school yard, playground, park, street, recreational site, and home; excludes non-accidental violence, assault, and passenger vehicle road trauma; may include falls; and age-group terminology includes Toddlers and Young Children (1-4 years), Children (5-12 years), and Adolescents (13 to < 18 years). Sport and exercise categories and individual examples are provided. This consensus definition of sport and exercise in paediatrics for concussion research and management will enable researchers and guideline development groups to expand paediatric concussion research and management guidelines to encompass the broad range of activities commonly associated with sport- and exercise-related concussion in children and adolescents and thus limit exclusion of relevant studies from systematic reviews and guideline development.

Scene-Adaptive Loader Trajectory Planning and Tracking Control.

Wheel loaders play a crucial role in daily production and transportation. With the rapid development of intelligence in passenger vehicles, freeing loader operators from high-risk and repetitive tasks has become a pressing issue. This paper presents a novel and efficient path planning and tracking framework tailored to the unique body structure and specific operating environment of loaders. We improve the Hybrid A* search algorithm based on the operational characteristics of loaders and integrate it with dynamically updated grid maps to enable the autonomous planning of loader operating paths in unstructured environments, meeting the efficiency requirements of production. Additionally, to address the challenge of poor trajectory tracking control accuracy caused by hydraulic articulated steering, we propose a new loader trajectory tracking controller based on the idea of hierarchical control. We use an extended state observer to compensate for unknown disturbances in the steering execution layer and employ fuzzy fractional-order PID to handle the nonlinearity of loaders. Field experiments using the proposed approach demonstrate that loaders can autonomously and in real-time complete tasks in dynamically changing operating scenarios.

Systematic Literature Review on Passenger Car Fire Experiments for Car Park Safety Design

Abstract To allow future creation of knowledge-based design fire scenarios for car fires, a systematic literature review was performed. Keywords “fire + passenger vehicle” and “fire + car” were filtered in Scopus, Science Direct and Web of Science databases for 1990–2024 period yielding 11 papers containing relevant data. A further citation mining on references revealed another 33. A total of 148 individual records of fire experiments were identified, with records of the heat release rate (or mass loss rate), total heat release and time to reach peak heat release rate. The database was subdivided by the car size and drivetrain, as well by the age of experiments. Analysing the course of experiments, common phases of fires have been identified, leading to another sub-division of the database by the location of the ignition source. It was found that fires initiated from the underneath the car did lead to higher peak HRR and a shorter time to peak compared to fires starting at other locations. Statistical distributions of peak HRR, time to peak HRR and THR are given for each sub-set of data. The average Heat of Combustion value of 25 MJ/kg (± 7 MJ/kg) was identified for the entire dataset.

Vehicle Body Vibration and Noise Impact on Driver and Passengers Analysis: The Case of the 29-Seat Thaco Garden TB79s Bus

Noise, Vibration, and Harshness (NVH) are critical factors influencing the comfort and satisfaction of vehicle occupants. NVH encompasses the sound levels generated during vehicle operation, the vibrations transmitted through the vehicle structure, and the perceived harshness of the ride quality. This study focuses on the NVH analysis of the Thaco Garden TB79S, a 29-seat passenger vehicle. The Finite Element Method (FEM) is applied to simulate the impact on the vehicle as it traverses two types of road surfaces, characteristic of Vietnam: rumble strips with varying frequencies and uneven roads with random excitation. The results reveal that the Sound Pressure Level (SPL) is within the frequency range from 0 to 200 Hz while the vehicle navigates on rumble strips. Further analysis of the vehicle's body and the air mass within the cabin identifies a resonance phenomenon at the driver's ear location at 176 Hz, resulting in a maximum SPL of 166.92 dB. Additionally, the study examines the noise formation within the cabin during a 25-second period as the vehicle travels over random road surfaces. The maximum sound pressure at the driver's position reaches 0.24 psi, with the SPL fluctuating primarily between 130 and 155 dB.

Bottom-up analysis for carbon emissions from passenger and freight transport sectors in Xi’an: a city-level study using MOVES and LMDI models

Abstract Road transportation is identified as one of the primary contributors to urban carbon emissions. This study employed a localized MOVES model, integrating high-resolution urban vehicle data, along with a categorical LMDI decomposition model, to conduct a detailed bottom-up analysis of carbon emissions from passenger and freight vehicles in Xi’an. The MOVES model was utilized to evaluate the inter annual variability of carbon emissions from road transportation sources. The LMDI models assessed the impact of six factors, focusing on microscopic traffic activities such as passenger/freight volume and turnover, vehicle ownership, mileage, carbon emission rate, vehicle types, and fuel types. The research indicates that carbon emissions in Xi’an increased significantly between 2012 and 2021, rising from 21.95 to 51.15 million tons, with an average annual growth rate of 9.9%. Passenger vehicles are the primary contributors to this increase. The emission patterns of passenger and freight vehicles differ notably due to various factors. For passenger transport, which includes passenger cars and school buses accounting for 97% of emissions, per capita vehicle turnover is the primary influencing factor. In contrast, for freight transport, combination long-haul trucks dominate emissions, comprising 65% of total freight emissions, with freight volume being the key influencing factor. By analyzing the factors driving carbon emissions from passenger and freight vehicles, this study provides valuable insights for reducing road traffic emissions in Xi’an and similar regions.

Optimizing multi-modal urban traffic flow: Utilizing macroscopic fundamental diagram and Model Predictive Control

Optimizing multi-modal urban traffic flow: Utilizing macroscopic fundamental diagram and Model Predictive Control

Surface transport emission reduction strategy in Bhutan

This study analyzes the surface transport emission reduction strategy in Bhutan. Considering 100% Electric Vehicle (EV) development by 2050, the estimated emission reduction is calculated based on kilometers traveled for passenger vehicles and ton kilometers traveled for freight mobility in the year 2022. The calculated values show combustion engine vehicle emissions (CO2: 1145 Gt, CO: 29.8 Gt, SO2: 2.9 Gt, NOx: 12.1 Gt, N2O: 0.009 Gt, CH4: 0.104 Gt, NMVOC: 5.8 Gt, and PM2.5: 0.072 Gt) compared to 100% EV emissions (CO2: 276 Gt) in gigatons (Gt) in 2050, where other emission categories are completely removed during the operation life of EVs. However, to meet the emission reduction potential, various technical challenges are to be fulfilled, such as electrification of freight mobility, rural road infrastructure quality development, the high modal share of public transport service, and at least the provision of 2500 MW as a base load in the electric grid network. Furthermore, qualifying for zero emissions by 2050 requires regular data updates, which is a concern. Bhutan is uniquely positioned to achieve EV zero emissions as its power generation mix is almost 100% renewables based predominantly driven by hydropower.

Travel Burden of Radiation Therapy in the Philippines.

Travel Burden of Radiation Therapy in the Philippines.

Probabilities of reaching required diffusion of granular energy technologies in European countries.

To support discussions around the feasibility of the energy transition, we present probabilistic projections of the expected baseline diffusion of solar photovoltaics, wind power, biogases, heat pumps, and low-carbon passenger vehicles in 39 European countries for 2023-2050 under current contextual conditions. We then compare the projected capacities against those required for reaching net-zero greenhouse gas emissions by 2050. We create our projections using 72 different variants of diffusion models that we validate using hindcasting (2012-2022) and weight according to their performance. We find a notable expected growth in solar photovoltaics, heat pumps, and battery electric vehicles in the majority of European countries. However, most countries are unlikely to reach the required capacities for net-zero emissions of wind power and biogases with high confidence, and battery electric vehicles with lower confidence. Probabilities and confidence levels of reaching required capacities of solar photovoltaics and heat pumps vary the most between countries.

Nonlinear bond graph model for investigating the effects of seat belt parameters on injury risk of the passenger

Severe braking is one of the major causes of damage to the vehicle occupant. In this article, the effect of seat belt on injury risk of the passenger during severe braking is investigated and optimized seat belt parameters based on different injury criteria is determined. A nonlinear bond graph model representing the dynamic behaviors of the vehicle, occupant and seat belt is developed. Considering the developed bond graph model, the state differential equations of the system are derived. Solving the governing equation, effect of initial velocities and braking torques of the vehicle and stiffness and damping of the seat belt on the system responses is obtained. Head injury criterion, neck injury criterion, and thorax injury criterion are used to evaluate the effects of seat belt parameters on injury risk of the vehicle passenger. According to these criteria and weighted injury criterion developed in this article, the seat belt optimized stiffness and damping are determined to minimize the occupant injury risk. The optimization results show that minimum injury for all criteria indexes is happened in the same stiffness and damping amount has crucial role on decreasing the risk of injury.

Anatomy of a Crash: Analysis of 102 Pedestrian and Bicyclist Fatalities.

Pedestrian and bicyclist fatalities have increased over the past decade in the United States. Factors proposed to explain this increase include the increased popularity of larger passenger vehicles, road design to accommodate faster-moving traffic, and poor road infrastructure. We analyzed a series of 102 pedestrian and bicyclist fatalities to determine which factors were involved. Results demonstrated substance abuse as the most common pertinent decedent medical history, a disproportionate number of crashes occurred during evening/nighttime hours, and most crashes involved larger passenger vehicles. The percentage of cases involving sport utility vehicles (SUVs) has increased over time. Injury pattern analysis demonstrated that smaller passenger vehicles at lower speeds were more likely to cause lower extremity fractures compared to SUVs. Alcohol was the most common decedent substance detected on toxicology, and decedents with a previous mental health history were more likely to have positive toxicology for illicit substances than those without. Sixty-three percent of cases lacked sidewalks, and 85% of cases lacked bike lanes. We compared the trends that we saw on a small scale to those seen nationally and uncovered certain novel associations from the perspective of medical examination.

Examining Fatal Motorcycle Crashes in Malaysia: Rider Age, Road Attributes and Collision Partner Dynamics

Abstract: - High severity crashes involving motorcycles in Malaysia were analyzed to understand the crash characteristics, crash partner, and crash scenarios. This would involve studying how these variables influence the occurrence and severity of fatal crashes. Based on the examination, countermeasures are emphasized from the perspective of technologies, particularly those available on passenger vehicles. The objective of this study is to identify key risk factors and provide insights for improving road safety policies and intervention strategies. The highest age group involved in motorcycle crashes are among 16-20, followed by 21-25. 62.7% occurred in daylight, 90.5% during good weather and 75.4% occurred in midblock. By comparing the engine capacity to the total industry volume, the highest risk is on motorcycles&gt;250 cc, as the production is only 0.29%, but contributes to 4.55% of fatal crashes. The highest crash partners are passenger cars at 30.84%, followed by trucks at 26.64% and single-vehicle accidents at 19.64%. In single crash accidents, road departure represents 56.7%, and control loss, 43.3%. The mandatory ABS in new motorcycles in Malaysia may help in reducing the number of stability losses during emergency braking. Except for rear-end crashes, passenger cars are the highest collision partner in all crash scenarios. Considering the frequency of crash scenarios and crash compatibility, crash avoidance technologies that could help reduce fatalities include autonomous emergency braking, blind spot detection, and lane-keeping assist.

A Systematic Review of Indoor Environmental Quality in Passenger Transport Vehicles of Tropical and Subtropical Regions

This systematic literature review (SLR) focuses on indoor environmental quality (IEQ) in passenger transport vehicles within tropical and subtropical regions. It specifically examines indoor air quality (IAQ), thermal comfort (TC), acoustic comfort (AC), and visual comfort (VC) of passenger vehicle cabins (PVCs) in auto rickshaws, sedans, trucks, bus rapid transits (BRTs), buses, trains, trams, metro systems, aircraft and ferries of tropical and subtropical regions. The SLR used the PRISMA approach to identify and review scientific studies between 2000 and 2024 on the IEQ of PVCs in the tropics. Studies reviewed were found in SCOPUS, Web of Science, Science Direct, and EBSCO databases including relevant citation references. Findings reveal a significant geographical imbalance in research, with most studies concentrated in tropical Asia (78.2%), while sub-Saharan Africa (8.2%), South America (11.8%), and Oceania (1.8%) are considerably underrepresented. In 113 studies, most addressed IAQ and TC but limited attention to AC and VC. Moreover, fewer studies have jointly addressed all the IEQ parameters, highlighting the need for a more comprehensive approach to IEQ for tropical PVCs. Several studies alluded to in-cabin commuter risk linked to PM2.5, PM10, carbon monoxide (CO), and volatile organic compounds (VOCs). These risks are exacerbated by traffic hotspots, poor ventilation, ambient pollution, overcrowding, and poor vehicle conditions. Additionally, thermal discomfort is compounded by extreme heat loads, inefficient HVAC systems, and high vehicle occupancy. Common gaps include a paucity of IEQ studies and inadequate IEQ regulations or adapted standards in developing tropics. Infrastructural and regulatory deficiencies have been identified, along with strategies for mitigation. Recommendations are for more holistic IEQ studies in the tropics, including exposure studies for emerging gaps in new indoor pollutants, integration of AI and IoT for sustainable ventilation strategies, and development of effective regulatory frameworks considering region-specific conditions. Finally, Policymakers are encouraged to establish localized IEQ standards, enforce regulations, and prioritize upgrades to transport infrastructure. The SLR findings emphasize the urgent need for targeted interventions in developing tropical regions to address disparities in IEQ, ensuring healthier and more sustainable transport environments that could be replicated across transport systems worldwide.

Analysis of Road User Satisfaction Passing Through The West Boulevard Highway and The Kelapa Gading - Pulo Gebang Toll Road

This study aims to analyze the satisfaction level of road users on Jalan Boulevard Barat Raya and the Kelapa Gading - Pulo Gebang Toll Road. Evaluating user satisfaction is crucial for assessing transportation infrastructure performance and prioritizing road maintenance and development. Using a quantitative approach, data was collected through questionnaires distributed to drivers and passengers of private and online four-wheeled vehicles. The research applied the Importance Performance Analysis (IPA) and Customer Satisfaction Index (CSI) methods, focusing on nine indicators from the Indonesian Ministerial Regulation No. 14 of 2017, including requirements, procedures, completion time, costs, service specifications, implementer competence, behavior, complaint handling, and facilities. The CSI results revealed that road users are "Very Satisfied" with both roads, with Jalan Boulevard Barat Raya scoring 90.7% and the Kelapa Gading - Pulo Gebang Toll Road scoring 90.85%. However, IPA analysis identified several variables in quadrant 1, indicating high importance but low performance. These variables include: (B1) reasonable tariffs without additional costs, (PP1) friendly and polite officers handling complaints, (SM1) availability of complaint forums, and (SP1) adequate supporting facilities. These findings highlight areas needing improvement to enhance user satisfaction further. Overall, the study underscores the importance of addressing specific service gaps to maintain high satisfaction levels among road users.

Analytical solution of vehicle phase-plane equilibria through the Root-Rational tyre model

Passenger vehicle steady-state behaviour has been investigated for a long time. Among the existing methods, the phase portrait is rather popular and useful. However, the computation of vehicle equilibria may only be done numerically. Furthermore, the numerical procedure must be repeated in case of changes in the inputs (e.g. steering angle). This paper proposes a new methodology to obtain an analytical solution of vehicle equilibria. The key is the definition of a new tyre model, denoted as Root-Rational (RR) tyre model, which allows inverting the vehicle dynamics equations in closed form. Using the proposed tyre model reduces the equilibria location problem to finding the roots of a third-order polynomial. After describing the procedure in detail, comparisons are made between the analytical solution and a classical numerical approach, either using the same RR tyre model or a more classical one. Results show great accuracy when locating the equilibria coordinates and a significantly reduced computational time, paving the way for innovative vehicle stability control algorithms based on the real-time identification of the stability region in the phase plane.

A Symmetry-Inspired Hierarchical Control Strategy for Preventing Rollover in Articulated Rollers

In off-road environments, the lateral rollover stability of articulated unmanned rollers (URs) is critical to ensure operational safety and efficiency. This paper introduces the concept of a rollover energy barrier (REB), a symmetry-based metric that quantifies the energy margin between the current state and the critical rollover threshold of articulated rollers. URs exhibit dynamic asymmetry due to their hydraulic steering systems, which differ significantly from traditional passenger vehicles. To address these challenges, we propose a hierarchical control framework inspired by the principles of dynamic symmetry. This framework integrates Nonlinear Model Predictive Control (NMPC) and Active Disturbance Rejection Control (ADRC): NMPC is used for trajectory planning by incorporating the REB into the cost function, ensuring rollover stability, while ADRC compensates for dynamic asymmetries, model uncertainties, and external disturbances during trajectory tracking. Simulation and experimental results validate the effectiveness of the proposed control strategy in enhancing the rollover stability and tracking performance of the URs under off-road conditions.

Speed Advisor for Fuel Consumption Minimisation Under Real Driving Conditions

This paper deals with minimisation of fuel consumption under real driving conditions using a vehicle speed advisor. The aim is to explore the potential of speed profile optimisation in real driving conditions while assessing the suitability of an application which recommends the driver the optimal vehicle speed sequence that minimises the fuel consumption on a particular route. The speed advisor is based on solving the Optimal Control problem of covering a particular route with minimum fuel consumption with a defined time constraint. The approach presented was applied to and implemented on a real passenger vehicle to obtain a trade-off between fuel consumption and travel time for several trips on the route. Experimental results are presented with and without advisory. With speed advisor, the results approach the pareto front with lesser dispersion. On the other hand, without advisory, the dispersion is higher and largely above the pareto front.