Sport Utility Vehicle Research Articles

A Novel Four-Wheel-Drive Hybrid Electric Sport Utility Vehicle with Double Planetary Gears

Hybrid technology must be applied to Sport Utility Vehicles (SUVs) to meet the stringent fuel economy and emission regulations in the near future. Current hybrid SUVs realize four-wheel-drive (4WD) function which could improve its drivability and handing stability, by adding a motor to the rear axle of conventional series, parallel and power-split hybrid architectures. However, the extra motor incur more cost for the hybrid powertrain. In this paper, a novel hybrid powertrain with double outputs is proposed for 4WD SUVs, which uses a pair of planetary gears to couple the gasoline engine, two electric machines, and both front and rear wheels. The dynamics of this hybrid powertrain is built up and analyzed firstly, then Dynamic Programming (DP) is used to calculate the optimal controls and best fuel economy. Results indicates this 4WD hybrid powertrain shows greater fuel economy improvement than conventional 4WD system.

Hyundai unveils next-gen FCEV NEXO at CES, plus home power

Korean automaker Hyundai Motor Company highlighted new technology concepts at the recent CES 2018 Consumer Electronics Show in Las Vegas, all focused on connecting future technology with evolving mobility solutions. Its new fuel cell electric vehicle will be called the NEXO, again a sport utility vehicle like its ix35/Tucson Fuel Cell predecessor. And the company showcased its ‘Hydrogen Life Vision’, featuring home applications for hydrogen power that move sustainable transportation advances into more everyday applications.

Design & Weight Optimization of a Wheel Rim for Sport Utility Vehicle.

Automobile have various parts which are important for good running of the vehicle. The most important safety components from a structural point of view are the road wheels. They are required to be lighter and more fascinating to the buyer all the time. This implies that it's important to perform a lot of accurate strength assessment on wheel styles. The wheel rim plays a major role in vehicle dynamics. This paper deals with the design and model of different wheel rims based on weight optimization and also structural analysis has been carried out. It has been compared with standard values by varying two different materials. In addition, from the obtained outputs of simulations and the weight optimization, we suggested Aluminium alloys as most suitable material for SUV. Model is created by using SOLIDWORKS software 2015 and structural analysis &; weight optimization is done by using ANSYS WORKBENCH 16.0.

Consistency Study between Female Preferences for SUV Shape Design and Designer Comprehension of These Preferences for the Chinese Market

Proportion of female consumers in Chinese Sports Utility Vehicle (SUV) market is rapidly growing, and appearance is the most important factor that affects their purchasing decision. However, little study about their preferences has been conducted. If traits and demands of target female consumers were not clearly understood, inconsistencies and deviation between consumer preferences and proposed designs for them might exist. In this study, traits, demands and preferences for SUV shape designof630 Chinese female were studied, then they were clustered into five typical groups. Then, 10 professional designers were invited to match SUVs for five groups, after that, a correlation analysis was conducted between the preferred SUVs of the five groups and the matched SUVs for them. Analysis results of two groups were negative correlations, which proved the real existence of misunderstanding of designers about traits and demands of female consumers. Finally, for a reference, feasible design solutions were provided for these two groups through a conjoint analysis based on their preference scores. The methods and final results could be incorporated into the SUV design process and provide references for the automobile industry.

A hierarchical Bayesian approach for examining heterogeneity in choice decisions

There is a vast behavioral decision theory literature that suggests different individuals may utilize and/or weigh different attributes of an object to form the basis of their opinions, attitudes, choices, and/or evaluations of such stimuli. This heterogeneity of information utilization and importance can be due to several different factors such as differing goals, level of expertise, contextual factors, knowledge accessibility, time pressure, involvement, mood states, task complexity, communication or influence of relevant others, etc. This phenomenon is particularly pertinent to the evaluation of stimuli involving large numbers of underlying attributes or features. We propose a new hierarchical Bayesian multivariate probit mixture model with variable selection accommodating such forms of choice heterogeneity. Based on a Monte Carlo simulation study, we demonstrate that the proposed model can successfully recover true parameters in a robust manner. Next, we provide a consumer psychology application involving consideration to buy choices for intended consumers of large Sports Utility Vehicles. The application illustrates that the proposed model outperforms several comparison benchmark choice models with respect to face validity and choice predictive validation performance.

Child seat belt guidelines: Examining the 4 feet 9 inches rule as the standard.

Current American Academy of Pediatrics recommendations regarding transition from child safety/booster seat to adult safety belt use indicate that children should be at least 4 feet 9 inches, 8 years old, or 80 pounds. Proper fit in the vehicle seat, assessed with a five-point fit test, should also be met. Although most children reach 4 feet 9 inches around age 8 years, each child and vehicle presents a unique combination; thus a child may not fit appropriately in all vehicle types using only the 4 feet 9 inches requirement. We enrolled children, aged 7 years to 12 years, into our study. Height, weight, and demographic data were obtained. A Child Passenger Safety Technician then performed the five-point fit test in each of a uniform lineup of five vehicles. Data were collected on fit in the standard vehicle seat and also in a booster seat. We set 90% as the threshold proportion of children who meet all criteria for proper fit to validate current recommendations of a height of 4 feet 9 inches. Data were collected on 388 children. The percentage of 90% proper fit was met in the compact car and small sport-utility vehicle (SUV). However, only 80 (77%) of 104 students (p < 0.0001) that were 4 feet 9 inches or higher fit properly in the large SUV, only 87 (83%) of 105 students (p = 0.02) fit properly in the pickup truck, and only 91 (89%) of 102 students (p = 0.74) fit properly in the minivan. Substantial proportions of children meeting current height guidelines for an adult seat belt do not meet safety requirements for fit, especially in larger, commonly used vehicles (large SUVs and trucks). This emphasizes the need for evaluation of fit by a trained personnel and/or development of standard back seat dimensions in all vehicles for maximum safety. Epidemiologic level 1.

Shock mitigation of pedestrians from sports utility vehicles impact using active pop-up and extended hood mechanisms: experimental work

This paper presents experimental results of shock mitigation of pedestrians from a frontal crash with a sports utility vehicle (SUV) by utilizing new active hood mechanisms; pop-up hood and extended hood. The pop-up hood mechanism to protect a pedestrian colliding with the hood area of a SUV is proposed and manufactured. Then, the deployment completion time of a whole active hood lift system, which significantly affects the injury sustained is measured and a headform impact test on the hood system is performed to evaluate shock mitigation of the pedestrian head impact. It is shown that using the proposed pop-up hood mechanism, the pedestrian head injury value can be reduced on the hood impact area for both children and adults. In addition, in this work the newly proposed extended hood mechanism is manufactured by considering beneficial aspects of relatively large-sized SUVs to protect pedestrians from collision with the windshield area. It is demonstrated that the proposed extended hood system can provide a much better protection effect for pedestrians compared to direct collision with the windshield only.

Emerging Technologies for Higher Fuel Economy Automobile Standards

Transportation systems contribute significantly to air pollution and ∼15% globally and ∼25% in the United States to emissions climate-changing gases. In the United States, the Corporate Average Fuel Economy (CAFE) standards for motor vehicles were significantly raised in 2012 for the first time in almost three decades. The standards now call for an average across manufacturers of 54.5 miles per gallon (mpg) for new passenger cars by 2025, or 163 grams per mile (g/mi) of greenhouse gas (GHG) emissions, and of 47 mpg (196 g/mi) by 2021. The light truck standards, which include minivans and sport utility vehicles, call for fuel economy levels of 31 mpg (287 g/mi) in 2021 and of 40 mpg (222 g/mi) in 2025. Given approximately equal expected splits between car and light truck sales, these estimates imply combined car and light truck fleet averages of ∼40 to 41 mpg (217 to 222 g/mi) in 2021 and 50 mpg (178 g/mi) in 2025. However, because automakers have strategies to reduce GHGs in parallel with fuel economy, the actual in-use fuel economy of the fleet is expected to be somewhat lower. In this review, several automobile technology advances are described and assessed for providing relatively cost-effective solutions to meet CAFE standards for fuel economy and GHG reductions through 2025. The key points this review makes are that (a) loopholes in the current regulations will allow automakers to meet CAFE program goals with relatively minor incremental improvements to current technologies through 2025 and that (b) going beyond the current program, past 2025 to higher fuel economy levels and lower GHG emissions approaching 100 g/mi, is likely to involve heavier use of newer technologies especially including drivetrain electrification.

Analysis of the economic and ecological performances in the transient regimes of the European driving cycle for a midsize SUV equipped with a DHEP, using the simulation platforms

Currently, the tendency of the car manufacturers is to continue the expansion of the global production of SUVs (Sport Utility Vehicle), while observing the requirements imposed by the new pollution standards by developing new technologies like DHEP (Diesel Hybrid Electric Powertrain). Experience has shown that the transient regimes are the most difficult to control from an economic and ecological perspective. As a result, this paper will highlight the behaviour of such engines that are provided in a middle class SUV (Sport Utility Vehicle), which operates in such states. We selected the transient regimes characteristic to the NMVEG (New Motor Vehicle Emissions Group) cycle. The investigations using the modelling platform AMESim allowed for rigorous interpretations for the 16 acceleration and 18 deceleration states. The results obtained from the simulation will be validated by experiments.

Design of An Electromagnetic Energy Harvesting System Applied to The Shock Absorber of A Sport Utility Vehicle : Part I. Single Permanent Magnet Layer Coreless Type

This paper deals with the design of an electromagnetic energy harvesting generator for the suspension system of a sport utility vehicle. The proposed generator is composed of a single coreless type permanent magnet layer, which increases flux density across the coil windings and eliminates flux leakage by using the Halbach PM array, thus improving the machine’s performance, including flux linkage and output power. The goal of the system is to regenerate energy from the kinetic energy of the suspension system of the sport utility vehicle. The proposed generator physically combines electrical and mechanical components, in which permanent magnets, coil windings, and back iron are attached to the body of the shock absorber. The design’s performance was investigated using the finite element method (FEM) and validated by comparison with experimental data.

Rural and Urban Differences in Passenger-Vehicle-Occupant Deaths and Seat Belt Use Among Adults - United States, 2014.

Problem/ConditionMotor-vehicle crashes are a leading cause of death in the United States. Compared with urban residents, rural residents are at an increased risk for death from crashes and are less likely to wear seat belts. These differences have not been well described by levels of rurality.Reporting Period2014.Description of SystemsData from the Fatality Analysis Reporting System (FARS) and the Behavioral Risk Factor Surveillance System (BRFSS) were used to identify passenger-vehicle–occupant deaths from motor-vehicle crashes and estimate the prevalence of seat belt use. FARS, a census of U.S. motor-vehicle crashes involving one or more deaths, was used to identify passenger-vehicle–occupant deaths among adults aged ≥18 years. Passenger-vehicle occupants were defined as persons driving or riding in passenger cars, light trucks, vans, or sport utility vehicles. Death rates per 100,000 population, age-adjusted to the 2000 U.S. standard population and the proportion of occupants who were unrestrained at the time of the fatal crash, were calculated. BRFSS, an annual, state-based, random-digit–dialed telephone survey of the noninstitutionalized U.S. civilian population aged ≥18 years, was used to estimate prevalence of seat belt use. FARS and BRFSS data were analyzed by a six-level rural-urban designation, based on the U.S. Department of Agriculture 2013 rural-urban continuum codes, and stratified by census region and type of state seat belt enforcement law (primary or secondary).ResultsWithin each census region, age-adjusted passenger-vehicle–occupant death rates per 100,000 population increased with increasing rurality, from the most urban to the most rural counties: South, 6.8 to 29.2; Midwest, 5.3 to 25.8; West, 3.9 to 40.0; and Northeast, 3.5 to 10.8. (For the Northeast, data for the most rural counties were not reported because of suppression criteria; comparison is for the most urban to the second-most rural counties.) Similarly, the proportion of occupants who were unrestrained at the time of the fatal crash increased as rurality increased. Self-reported seat belt use in the United States decreased with increasing rurality, ranging from 88.8% in the most urban counties to 74.7% in the most rural counties. Similar differences in age-adjusted death rates and seat belt use were observed in states with primary and secondary seat belt enforcement laws.InterpretationRurality was associated with higher age-adjusted passenger-vehicle–occupant death rates, a higher proportion of unrestrained passenger-vehicle–occupant deaths, and lower seat belt use among adults in all census regions and regardless of state seat belt enforcement type.Public Health ActionsSeat belt use decreases and age-adjusted passenger-vehicle–occupant death rates increase with increasing levels of rurality. Improving seat belt use remains a critical strategy to reduce crash-related deaths in the United States, especially in rural areas where seat belt use is lower and age-adjusted death rates are higher than in urban areas. States and communities can consider using evidence-based interventions to reduce rural-urban disparities in seat belt use and passenger-vehicle–occupant death rates.

Using fixed-parameter and random-parameter ordered regression models to identify significant factors that affect the severity of drivers’ injuries in vehicle-train collisions

This study attempts to identify significant factors that affect the severity of drivers’ injuries when colliding with trains at railroad-grade crossings by analyzing the individual-specific heterogeneity related to those factors over a period of 15 years. Both fixed-parameter and random-parameter ordered regression models were used to analyze records of all vehicle-train collisions that occurred in the United States from January 1, 2001 to December 31, 2015. For fixed-parameter ordered models, both probit and negative log–log link functions were used. The latter function accounts for the fact that lower injury severity levels are more probable than higher ones. Separate models were developed for heavy and light-duty vehicles. Higher train and vehicle speeds, female, and young drivers (below the age of 21 years) were found to be consistently associated with higher severity of drivers’ injuries for both heavy and light-duty vehicles. Furthermore, favorable weather, light-duty trucks (including pickup trucks, panel trucks, mini-vans, vans, and sports-utility vehicles), and senior drivers (above the age of 65 years) were found be consistently associated with higher severity of drivers’ injuries for light-duty vehicles only. All other factors (e.g. air temperature, the type of warning devices, darkness conditions, and highway pavement type) were found to be temporally unstable, which may explain the conflicting findings of previous studies related to those factors.

Handling Delays in Yaw Rate Control of Electric Vehicles Using Model Predictive Control With Experimental Verification

In this paper, a new approach is proposed to deal with the delay in vehicle stability control using model predictive control (MPC). The vehicle considered here is a rear-wheel drive electric (RWD) vehicle. The yaw rate response of the vehicle is modified by means of torque vectoring so that it tracks the desired yaw rate. Presence of delays in a control loop can severely degrade controller performance and even cause instability. The common approaches for handling delays are often complex in design and tuning or require an increase in the dimensions of the controller. The proposed method is easy to implement and does not entail complex design or tuning process. Moreover, it does not increase the complexity of the controller; therefore, the amount of online computation is not appreciably affected. The effectiveness of the proposed method is verified by means of carsim/simulink simulations as well as experiments with a rear-wheel drive electric sport utility vehicle (SUV). The simulation results indicate that the proposed method can significantly reduce the adverse effect of the delays in the control loop. Experimental tests with the same vehicle also point to the effectiveness of this technique. Although this method is applied to a vehicle stability control, it is not specific to a certain class of problems and can be easily applied to a wide range of model predictive control problems with known delays.

Investigation of factors affecting the injury severity of single-vehicle rollover crashes: A random-effects generalized ordered probit model

Rollover crashes are responsible for a notable number of serious injuries and fatalities; hence, they are of great concern to transportation officials and safety researchers. However, only few published studies have analyzed the factors associated with severity outcomes of rollover crashes. This research has two objectives. The first objective is to investigate the effects of various factors, of which some have been rarely reported in the existing studies, on the injury severities of single-vehicle (SV) rollover crashes based on six-year crash data collected on the Malaysian federal roads. A random-effects generalized ordered probit (REGOP) model is employed in this study to analyze injury severity patterns caused by rollover crashes. The second objective is to examine the performance of the proposed approach, REGOP, for modeling rollover injury severity outcomes. To this end, a mixed logit (MXL) model is also fitted in this study because of its popularity in injury severity modeling. Regarding the effects of the explanatory variables on the injury severity of rollover crashes, the results reveal that factors including dark without supplemental lighting, rainy weather condition, light truck vehicles (e.g., sport utility vehicles, vans), heavy vehicles (e.g., bus, truck), improper overtaking, vehicle age, traffic volume and composition, number of travel lanes, speed limit, undulating terrain, presence of central median, and unsafe roadside conditions are positively associated with more severe SV rollover crashes. On the other hand, unpaved shoulder width, area type, driver occupation, and number of access points are found as the significant variables decreasing the probability of being killed or severely injured (i.e., KSI) in rollover crashes. Land use and side friction are significant and positively associated only with slight injury category. These findings provide valuable insights into the causes and factors affecting the injury severity patterns of rollover crashes, and thus can help develop effective countermeasures to reduce the severity of rollover crashes. The model comparison results show that the REGOP model is found to outperform the MXL model in terms of goodness-of-fit measures, and also is significantly superior to other extensions of ordered probit models, including generalized ordered probit and random-effects ordered probit (REOP) models. As a result, this research introduces REGOP as a promising tool for future research focusing on crash injury severity.

Sport utility vehicle seat structure simulation of frontal oblique crash

A seat structure of the Sport Utility Vehicle (SUV) has been gained more attention in developing lightweight design using available materials differently in grades and their strengths. The SUV industry has drastically shown an incessant growth in present. By this scenario, safety issues are of interest mainly by users. This work, therefore, simulates and analyzes an SUV’s seat for stress distribution and deformation of its structure using ??inite element method. The seat is situated in the SUV where it is crashed in the front by oblique angle from 0 degree to 15 degree adjacent to the straight direction in both right and left sides. This type of collision is considered to be an accident of vehicle resulting in serious injuries. The analysis employs an explicit dynamic simulation during the real frontal impact and includes a direct contact of Asia-EvaRID (ER) model with backrest. Under the test by simulation conforming industrial standards, ECE standards in particular, the seat structure parts of backrest relative to the sled were measured in displacement of deformation with a minimum interval time of accident, for the velocity ranging from 60 km/h to 100 km/h. The results have been explored that the seat structure withstanding the stress distribution and deformation under static load evaluation testing was affected by vehicle velocity and crash direction in an accident. The analysis of the left and right side impact when fastened seat belt generated the maximum stress in the direction of 12.85 degree head and 6.04 degree from the lateral axis and 4.28 degree head and 2.01 degree chest from the lateral axis, respectively. The unfastened seat belt case has shown the maximum distribution at 9 degree head and degree chest directions over the peak time.

Risk of serious injury of occupants involved in frontal crashes of cab-over-type trucks

ABSTRACTObjectives: Truck vehicles (TVs) have a different structure and stiffness than non-TVs and are used commercially for transporting goods. This study aimed to analyze whether truck occupants have a greater risk of serious injury than those of other types of vehicles.Methods: Crash data were obtained from the Korean In-Depth Data Analysis Study (KIDAS) for calendar years 2011–2016. Vehicles involved in frontal crash were included and classified into TVs and non-TVs (passenger cars and sports utility vehicles). We compared the demographic characteristics and serious injuries by body region between the 2 groups and analyzed factors that contributed to the serious injury severity from frontal crashes.Results: The analysis was based on 884 occupants; 177 (20.0%) were in TVs and 707 (80.0%) were in non-TVs. Non-TVs had more frontal airbags deployments than TVs (50.9% vs. 3.4%, P <.01). TV occupants were 4.8 times more likely to have a serious lower extremity (LE) injury (adjusted odds ratio [AOR] = 4.820; 95% confidence interval [CI], 2.407–9.653) and 2.5 times to have a serious abdominal injury (AOR = 2.465; 95% CI, 1.108–5.487) compared to non-TV occupants.Conclusions: Truck occupants had more serious LE and abdominal injuries than those of other types of vehicles in frontal crashes. Structural improvement and legislative efforts to develop safety systems are necessary to improve the safety of truck occupants.

A driver-adaptive stability control strategy for sport utility vehicles

ABSTRACTConventional vehicle stability control (VSC) systems are designed for average drivers. For a driver with a good driving skill, the VSC systems may be redundant; for a driver with a poor driving skill, the VSC intervention may be inadequate. To increase safety of sport utility vehicles (SUVs), this paper proposes a novel driver-adaptive VSC (DAVSC) strategy based on scaling the target yaw rate commanded by the driver. The DAVSC system is adaptive to drivers’ driving skills. More control effort would be exerted for drivers with poor driving skills, and vice versa. A sliding mode control (SMC)-based differential braking (DB) controller is designed using a three degrees of freedom (DOF) yaw-plane model. An eight DOF nonlinear yaw-roll model is used to simulate the SUV dynamics. Two driver models, namely longitudinal and lateral, are used to ‘drive’ the virtual SUV. By integrating the virtual SUV, the DB controller, and the driver models, the performance of the DAVSC system is investigated. The simulations demonstrate the effectiveness of the DAVSC strategy.

Comparative life cycle assessment of sport utility vehicles with different fuel options

Sport utility vehicles typically have lower fuel economy due to their high curb weights and payload capacities as well as their potential to cause serious environmental impacts. In light of this fact, a life cycle assessment is carried out in this study to assess their cradle-to-grave environmental impacts for life cycle phases ranging from manufacturing to end-of-life recycling. A hybrid economic input-output life cycle assessment (EIO-LCA) method is used in this research paper to estimate the environmental impacts (greenhouse gas emissions, energy consumption, and water withdrawal) of sport utility vehicles. This life cycle assessment is also supplemented with a sensitivity analysis, using a Monte Carlo simulation to estimate the possible ranges for total mileage of operation and fuel economy, and to account for the sensitivity of the EIO-LCA output. The operation phase is the major contributor to the overall life cycle impact of sport utility vehicles in each fuel/power category. Furthermore, among the selected vehicles in this study, the battery electric vehicle has the lowest greenhouse gas emissions (77.2 tonnes) and the lowest energy consumption (1046.8 GJ) even though the environmental impact indicators for the battery manufacturing process are significantly large. The plug-in hybrid vehicle, on the other hand, demonstrates an optimal performance between energy use and water withdrawal (1172.9 GJ of energy consumption and 1370 kgal of water withdrawal). In addition, all of the fuel-powered vehicles demonstrated similar environmental performances in terms of greenhouse gas emissions, which ranged between 100 and 110 tonnes, but the hydrogen fuel cell vehicle had a significantly large water withdrawal (2253.2 kgal). Since the majority of the overall impact stems from the operation of the vehicle in question, their complete elimination of tailpipe emissions and their high energy efficiency levels make battery electric vehicles a viable green option for sport utility vehicles. However, there are certain uncertainties beyond the scope of this study that can be considered in future studies to improve upon this assessment, including (but not limited to) regional differences in source of electricity generation and socio-economic impacts.

Evaluation of Perceived Exertion and Satisfaction in Opening and Closing Tailgates of Sport Utility Vehicles

Evaluation of Perceived Exertion and Satisfaction in Opening and Closing Tailgates of Sport Utility Vehicles

The Effect of Passive Base Ventilation on the Aerodynamic Drag of a Generic SUV Vehicle

Sports Utility Vehicles (SUVs) typically have a blunt rear end shape (for design and practicality), however this is not beneficial for aerodynamic drag. Drag can be reduced by a number of passive and active methods such as tapering and blowing into the base. In an effort to combine these effects and to reduce the drag of a visually square geometry slots have been introduced in the upper side and roof trailing edges of a squareback geometry, to take air from the freestream and passively injects it into the base of the vehicle to effectively create a tapered body. This investigation has been conducted in the Loughborough University’s Large Wind Tunnel with the ¼ scale generic SUV model. The basic aerodynamic effect of a range of body tapers and straight slots have been assessed for 0° yaw. This includes force and pressure measurements for most configurations. The slots generate useful, but small, drag reductions with the best configurations giving reductions in drag coefficient (Cd) of approximately 0.01, whereas the best taper configurations reduce Cd by close to 0.035. The slots also have a tendency to modify the lift.