Browse Topic: Comfort

Items (2,038)
The comfort of seats increasingly becomes a crucial factor in the overall driving experience, particularly as vehicles become increasingly integrated into people’s daily lives. Passengers often maintain a relatively fixed posture and have close contact with the seat for extended periods of time, leading to issues such as heat, humidity, and stickiness. In order to enhance the thermal comfort experienced by occupants, manufacturers are no longer satisfied with ensuring the thermal comfort performance of vehicles only through the HVAC system in the cabin, but also developed a microclimate control seat that adjusts the temperature through ventilation between the contact surface of the seat and the human body, trying to improve the thermal comfort of passengers more effectively. However, the ventilation ducts of these seats are commonly designed based on empirical or autonomous standards, and their effectiveness is subsequently assessed through test or simulation, typically under unloaded
Zhang, TianmingRen, JindongZhang, Haonan
This study investigates the effects of replacing a 6-speed gearbox with a 5-speed gearbox in a sports vehicle, while keeping all other parameters constant. Through computational simulations, data is collected for comparative performance analysis. The study aims to understand the potential implications of this change on acceleration, fuel efficiency, engine response, as well as aspects such as driver comfort. The results may provide valuable insights for the automotive industry, guiding future transmission design and engineering decisions
Marinho, Gabriel Jannuzzide Campos, Josué QueirozLopes, Elias Dias RossiRodrigues, Gustavo Simão
Throughout the vehicles industry and electrification, vehicle ride comfort, road holding, and fuel/charge economy have always been important considerations for the design and development of shock absorbers. Vehicle suspension is one of the oscillating power dissipation sources in which the undesired mechanical energy is dissipated into heat waste. Therefore, in this study a regenerative MacPherson strut is modeled and validated to investigate the vehicle vertical dynamics performance as well as the harvestable power that can be used to charge batteries or power vehicle electrical loads. The optimal design parameters of the regenerative MacPherson strut (RE.M.S) is obtained by using multi-object genetic algorithm (MOGA) optimization for a better trade-off between regenerated power, ride comfort, and road holding. The results showed that RE.M.S can function as a semi-active shock absorber as change of duty cycle of charging circuit. Furthermore, the optimal selection of the design
Hegazy, Ahmed H.A.Kaldas, Mina M.Soliman, Aref M.A.Huzayyin, A.S.
Single lane changing is one of the typical scenarios in vehicle driving. Planning an appropriate lane change trajectory is crucial in autonomous and semi-autonomous vehicle research. Existing polynomial trajectory planning mostly uses cubic or quintic polynomials, neglecting the lateral jerk constraints during lane changes. This study uses seventh-degree polynomials for lane change trajectory planning by considering the vehicle lateral jerk constraints. Simulation results show that the utilization of the seventh-degree method results in a 41% reduction in jerk compared to the fifth-degree polynomial. Furthermore, this study also proposes lane change trajectory schemes that can cater to different driving styles (e.g., safety, efficiency, comfort, and balanced performance). Depending on the driving style, the planned lane change trajectory ensures that the vehicle achieves optimal performance in one or more aspects during the lane change process. For example, with the trajectory that
Lai, FeiHuang, Chaoqun
Autonomous driving technology plays a crucial role in enhancing driving safety and efficiency, with the decision-making module being at its core. To achieve more human-like decision-making and accommodate drivers with diverse styles, we propose a method based on deep reinforcement learning. A driving simulator is utilized to collect driver data, which is then classified into three driving styles—aggressive, moderate, and conservative—using the K-means algorithm. A driving style recognition model is developed using the labeled data. We then design distinct reward functions for the Deep Q-Network (DQN), Proximal Policy Optimization (PPO), and Soft Actor-Critic (SAC) algorithms based on the driving data of the three styles. Through comparative analysis, the SAC algorithm is selected for its superior performance in balancing comfort and driving efficiency. The decision-making models for different styles are trained and evaluated in the SUMO simulation environment. The results indicate that
Shen, ChuanliangZhang, LongxuShi, BowenMa, XiaoyuanLi, YiHu, Hongyu
The parametrized twist beam suspension is a pivotal component in the automotive industry, profoundly influencing the ride comfort and handling characteristics of vehicles. This study presents a novel approach to optimizing twist beam suspension systems by leveraging parametric design principles. By introducing a parameter-driven framework, this research empowers engineers to systematically iterate and fine-tune twist beam designs, ultimately enhancing both ride quality and handling performance. The paper outlines the theoretical foundation of parametrized suspension design, emphasizing its significance in addressing the intricate balance between ride comfort and dynamic stability. Through a comprehensive examination of key suspension parameters, such as twist beam profile, material properties, and attachment points, the study demonstrates the versatility of the parametric approach in tailoring suspension characteristics to meet specific performance objectives. To validate the
Pakala, Pradeep KumarGanesh, Lingadalu
Modal performance of a vehicle body often influences tactile vibrations felt by passengers as well as their acoustic comfort inside the cabin at low frequencies. This paper focuses on a premium hatchback’s development program where a design-intent initial batch of proto-cars were found to meet their targeted NVH performance. However, tactile vibrations in pre-production pilot batch vehicles were found to be of higher intensity. As a resolution, a method of cascading full vehicle level performance to its Body-In-White (BIW) component level was used to understand dynamic behavior of the vehicle and subsequently, to improve structural weakness of the body to achieve the targeted NVH performance. The cascaded modal performance indicated that global bending stiffness of the pre-production bodies was on the lower side w.r.t. that of the design intent body. To identify the root cause, design sensitivity of number and footprint of weld spots, roof bows’ and headers’ attachment stiffness to BIW
Titave, Uttam VasantZalaki, NitinNaidu, Sudhakara
In the realm of commercial vehicle design, enhancing the durability of bumpers and headlamps is paramount for ensuring safety and reducing maintenance costs. This study explores the development of a lightweight bumper design with optimized resonance frequency to improve the durability of these critical components. The research focuses on innovative design techniques to achieve a balance between weight reduction and structural integrity. The primary objective is to minimize the impact forces transmitted to the bumper and headlamp assemblies during vibrations. By employing finite element analysis (FEA) and experimental validation, the study identifies the optimal resonance frequency that mitigates the risk of resonance-induced damage. Additionally, the study examines the influence of geometric modifications on the bumper’s performance. Various design iterations are analyzed to determine the most effective configuration for enhancing durability while maintaining compliance with industry
Pandey, SudheerGanesan, Balaji
Born Electric SUVs generally feature a high centre of gravity (CG) with greater rear axle weight. They use sophisticated multi-link suspension, which offers large scope for ride comfort and handling optimisation. The development costs and time associated with the process will position the vehicle in a premium segment. Usually, the twist beam (RTB) is used in lower rear axle weight category vehicles due to its simple design and cost effectiveness. This study showcases exploration for implementation of RTB on higher weight category vehicles, which usually uses multi-link suspension. The limitation of the twist beam is to exhibit lateral force compliance oversteer during cornering, due to large moment arm from wheel centre to twist beam bush. Lack of lateral stiffness when compared to multi-link suspension causes delayed rear axle yaw response. It also has reduced scope in ride-handling optimization due to its simple structure and kinematics. So, in order to maximize the performance
Prabhakara Rao, VageeshRasal, ShraddheshAsthana, ShivamM, SudhanVellandi, Vikraman
A silicone membrane for wearable devices is more comfortable and breathable thanks to better-sized pores made with the help of citric acid crystals. The new preparation technique fabricates thin, silicone-based patches that rapidly wick water away from the skin. The technique could reduce the redness and itching caused by wearable biosensors that trap sweat beneath them. The technique was developed by bioengineer and professor Young-Ho Cho and his colleagues at KAIST and reported in the journal Scientific Reports
Researchers have been testing ways to continuously and more comfortably detect these tiny fluctuations in pressure. A prototype smart contact lens measures eye pressure accurately, regardless of temperature. The contact lens wirelessly transmits real-time signals about eye pressure across a wide range of temperatures
Abstract Semi-active suspensions have drawn particular attention due to their superior performance over the other types of suspensions. One of their advantages is that their damping coefficient can be controlled without the need for any external source of power. In this study, three control approaches are implemented on a quarter-car model using MATLAB/Simulink. The investigated control methodologies are Acceleration Driven Damper, Power Driven Damper, and H∞ Robust Control. The three controllers are known as comfort-oriented approaches. H∞ Robust Control is an advanced method that guarantees transient performance and rejects external disturbances. It is shown that H∞ with the proposed modification, has the best performance although its relatively high cost of computation could be potentially considered as a drawback
Ghasemalizadeh, OmidTaheri, SaiedSingh, AmandeepGoryca, Jill
ABSTRACT One of the main thrusts in current Army Science & Technology (S&T) activities is the development of occupant-centric vehicle structures that make the operation of the vehicle both comfortable and safe for the soldiers. Furthermore, a lighter weight vehicle structure is an enabling factor for faster transport, higher mobility, greater fuel conservation, higher payload, and a reduced ground footprint of supporting forces. Therefore, a key design challenge is to develop lightweight occupant-centric vehicle structures that can provide high levels of protection against explosive threats. In this paper, concepts for using materials, damping and other mechanisms to design structures with unique dynamic characteristics for mitigating blast loads are investigated. The Dynamic Response Index (DRI) metric [1] is employed as an occupant injury measure for determining the effectiveness of the each blast mitigation configuration that is considered. A model of the TARDEC Generic V-Hull
Jiang, WeiranVlahopoulos, NickolasCastanier, Matthew P.Thyagarajan, RaviMohammad, Syed
In order to modify both stiffness and damping rates according to various road conditions, this research introduces a pneumatic spring in conjunction with a magnetorheological (MR) fluid damper as a single suspension unit for each wheel in the truck. Preventing weight transfer and improving riding comfort during braking, acceleration, and trajectory prediction are the main objectives. A two-axle truck has been used, consisting of three degrees of freedom for the sprung mass, including vertical, pitch, and roll motions, and four degrees of freedom for the unsprung masses, which have been redesigned according to the different types of springs and dampers. Pneumatic-controlled springs, often referred to as dynamic or classic models, replace laminated leaf springs commonly found in vehicles. Additionally, an MR damper replaces a hydraulic double-acting telescopic shock absorber. These models are studied to evaluate the effect of pneumatic spring parameters on truck dynamics. Pneumatic
Shehata Gad, AhmedEl-Zomor, Haytham M.
Airflow directionality in a vehicle cabin is one of the concerns of car owners, researchers, and vehicle manufacturers. After exposed/parked in hot ambient condition for a long time, HVAC system normally takes few minutes to cool down and reach an acceptable cabin temperature for the passenger comfort. To ensure proper airflow distribution inside the cabin, the AC duct & vanes ability to direct airflow must be evaluated. Objective of this work is to propose a methodology for developing the vane design of AC system duct using CFD approach. Two different goals are attempted. Firstly, the effect of horizontal and vertical vane angle on airflow directionality is investigated with DoE approach. Then factors influencing the airflow directionality are investigated using factorial study approach. CFD based factorial analysis (L9 orthogonal array) was conducted using three components at three levels. The impact of number of horizontal vanes, number of vertical vanes and distance between them on
Mahesh, ABaskar, SubramaniyanRaju, KumarGopinathan, Nagarajan
Three dynamic models of a passenger car including the one-dimensional dynamic model, two-dimensional dynamic model, and three-dimensional dynamic model are built to evaluate the ride quality of the passenger car as well as the isolating performance of the SNS (structure of negative stiffness). The decrease of the root-mean-square (RMS) accelerations in the seat and car’s body shaking is the research goal. The investigation results indicate that under all working conditions including the various excitations of the road surface and various velocities of the passenger car, the seat’s acceleration with SNS is strongly ameliorated in comparison without SNS in all three models of the passenger car. Particularly, the RMS seat acceleration with SNS in one-, two-, and three-dimensional models is strongly reduced in comparison without SNS by 76.87%, 66.15%, and 70.59%, respectively. Thus, the seat’s SNS has a good effect in isolating the vertical vibration of the passenger car’s seat. However
Zhang, LeiLi, TaoYang, Guixing
Today, almost all passenger vehicles are equipped with Mobile Air Conditioning (MAC) systems to provide thermal comfort to occupants. To enhance cabin cooling down rate, two approaches are possible viz. increasing the MAC system capacity or reducing heat ingress into the vehicle cabin. The first approach is likely to have a negative impact on energy efficiency. The latter approach considers the deployment of alternate passive cabin cooling technologies. Among these, the deployment of uniquely developed coatings on metal, plastic and glass surfaces of the cabin is one option. The assessment of such coatings is usually done only at severe ambient conditions (>40°C), which may not be sufficient. These coatings need to be validated across all climatic seasons of the year, for assessing their effectiveness on passenger thermal comfort. The current work along with simulation studies, takes into account additional parameters such as the ‘feeling of hotness’ when one enters a hot-soaked cabin
Deshmukh, GaneshKulkarni, Shridhar DilipraoVarma, MohitJaybhay, SambhajiKapoor, SangeetTilekar, Pravin
In order to meet the driving characteristics and needs of different types of drivers and to improve driving comfort and safety, this article designs personalized variable transmission ratio schemes based on the classification results of drivers’ steering characteristics and proposes a switching strategy for selecting variable transmission ratio schemes in response to changes in driver types. First, data collected from driving simulator experiments are used to classify drivers into three categories using the fuzzy C-means clustering algorithm, and the steering characteristics of each category are analyzed. Subsequently, based on the steering characteristics of each type of driver, suitable speed ranges, steering wheel travel, and yaw rate gain values are selected to design the variable transmission ratio, forming personalized variable transmission ratio schemes. Then, a switching strategy for variable transmission ratio schemes is designed, using a support vector machine to build a
Chen, ChenZheng, HongyuZong, Changfu
Vibration comfort is a critical factor in assessing the overall performance of engineering machinery, with significant implications for operator health and safety. However, current evaluation methods lack specificity for construction machinery, impeding accurate prediction of vibration comfort and hindering the optimization of noise, vibration, and harshness (NVH) performance. To address this challenge, this article proposes a model that combines a random forest with a genetic algorithm (GA-RF) to enable rapid and accurate prediction of vibration comfort in construction machinery cabins. The approach begins with an improved objective evaluation methodology for extracting key features from vibration signals at five measurement points: seat, floor, back, and left and right armrests. Additionally, subjective evaluation technology, combining semantic differential and rating scales, is employed to capture operators’ personal comfort perceptions. The implementation of the GA-RF model
Zhao, JianYin, YingqiChen, JiangfeiZhao, WeidongDing, WeipingHuang, Haibo
A research team at The University of Texas at Austin created a noninvasive electroencephalogram (EEG) sensor that was installed in a Meta VR headset that can be worn comfortably for long periods. The EEG measures the brain’s electrical activity during the immersive VR interactions
For engineers working on soft robotics or wearable devices, keeping things light is a constant challenge: heavier materials require more energy to move around, and — in the case of wearables or prostheses — cause discomfort. Elastomers are synthetic polymers that can be manufactured with a range of mechanical properties, from stiff to stretchy, making them a popular material for such applications. But manufacturing elastomers that can be shaped into complex 3D structures that go from rigid to rubbery has been unfeasible until now
A new groundbreaking “smart glove” is capable of tracking the hand and finger movements of stroke victims during rehabilitation exercises. The glove incorporates a sophisticated network of highly sensitive sensor yarns and pressure sensors that are woven into a comfortable stretchy fabric, enabling it to track, capture, and wirelessly transmit even the smallest hand and finger movements
While semi-active suspensions help improve the ride comfort and road-holding capacity of the vehicle, they tend to be reactive and thus leave a lot of room for improvement. Incorporating road preview data allows these suspensions to become more proactive rather than reactive and helps achieve a higher level of performance. A lot of preview-based control algorithms in literature tend to require high computational effort to arrive at the optimal parameters thus making it difficult to implement in real time. Other algorithms tend to be based upon lookup tables, which classify the road input into different categories and hence lose their effectiveness when mixed types of road profiles are encountered that are difficult to classify. Thus, a novel MPC (model predictive control)-based algorithm is developed which is easy to implement online and more responsive to the varying road profiles that are encountered by the vehicle. The efficacy of the algorithm is tested against a numerical methods
Thamarai Kannan, Harish KumarFerris, John B.
In the highly competitive landscape of the automotive industry, enhancing ride comfort has become a paramount challenge for automakers. To address this challenge, a novel double damper suspension system has been investigated. This system, featuring two single dampers operating collaboratively as an integrated unit, is analyzed with a dual focus: a comprehensive comparison of various control algorithms to identify the one offering superior comfort and the experimental validation of these findings. The modeling process, executed in Simulink, encompasses the representation of pressure, discharge, and force equations, along with the development and testing of multiple control algorithms. The study employs a shock dynamometer, utilizing both the double damper and a single semi-active damper as test subjects in a pseudo-quarter-car test bed setup. Throughout the experimental phase, solenoid actuation in the dampers is guided by specific control logic, utilizing acceleration data for the
Hamedi, BehzadShrikanthan, SudarshanTaheri , Saied
The administration of high-dose biologics presents unique challenges and opportunities for the devel opment of drug-delivery systems. With the advent of innovative reusable drug-delivery devices, the landscape of patient adherence and comfort is evolving significantly. These advanced devices are designed to handle higher concentrations and viscosities of therapeutic drugs, allowing for new routes of administration that can be managed by patients themselves at home
Occupant packaging is one of the key tasks involved in the early architectural phase of a vehicle. Accommodation, as a convention, is generally considered related to a car’s interior. Typical roominess metrics of the occupant like hip room, shoulder room, and elbow room are defined with the door in its closed condition. Several other roominess metrics like knee room, leg room, head room, and the like are also specified. While all the guidelines are defined with doors in their closed condition, it is also important to consider the dynamics that exist while the occupant is entering the vehicle. This article expands the traditional understanding of occupant accommodation beyond conventionally considering the vehicle interior’s ability to accommodate anthropometry. It broadens the scope to include dynamic conditions, such as when doors are opened, providing a more realistic and practical perspective. As a luxury car manufacturer, it is important to ensure the best overall customer
Rajakumaran, SriramSreenivas, Kalyan
This research aims at understanding how the driver interacts with the steering wheel, in order to detect driving strategies. Such driving strategies will allow in the future to derive accurate holistic driver models for enhancing both safety and comfort of vehicles. The use of an original instrumented steering wheel (ISW) allows to measure at each hand, three forces, three moments, and the grip force. Experiments have been performed with 10 nonprofessional drivers in a high-end dynamic driving simulator. Three aspects of driving strategy were analyzed, namely the amplitudes of the forces and moments applied to the steering wheel, the correlations among the different signals of forces and moments, and the order of activation of the forces and moments. The results obtained on a road test have been compared with the ones coming from a driving simulator, with satisfactory results. Two different strategies for actuating the steering wheel have been identified. In the first strategy, the
Previati, GiorgioMastinu, GianpieroGobbi, Massimiliano
The usage of the inerter and its studies has greatly developed in recent years as it offers better performance compared to passive systems and has lower cost and power consumption than active and semi-active systems. This article focuses on studying a half-vehicle model to obtain the optimal layout of the mechatronic inerter, spring, and damper suspension system (ISD) for comfort enhancement with the aid of the structure-immittance approach, ensuring structural simplicity. The mechatronic inerter, which consists of a single capacitance, resistance, and inductance, is added to a half-vehicle model composed of an inerter, spring, and damper. All possible layouts are studied to achieve the optimal design layout. Evaluation criteria such as the performance index, system peak-to-peak value, and settling time are utilized to assess body acceleration, thereby improving passenger comfort. Furthermore, the system’s impact on dynamic tire load and suspension working space under diverse road
Kolta, Michael M.H.Mansour, Nader A.Lashin, ManarSoliman, Aref M.A.
The optimization and further development of automated driving functions offers great potential to relieve the driver in various driving situations and increase road safety. Simulative testing in particular is an indispensable tool in this process, allowing conclusions to be drawn about the design of automated driving functions at a very early stage of development. In this context, the use of driving simulators provides support so that the driving functions of tomorrow can be experienced in a very safe and reproducible environment. The focus of the acceptance and optimization of automated driving functions is particularly on vehicle lateral control functions. As part of this paper, a test person study was carried out regarding manual vehicle lateral control on the dynamic vehicle road simulator at the Institute of Automotive Engineering. The basis for this is the route generation as a result of the evaluation of curve radii from several hundred thousand kilometers of real measurement
Iatropoulos, JannesPanzer, AnnaHenze, Roman
Linear actuators, in particular, electromechanical linear actuators, have become integral components of modern medical devices because of their high precision, accuracy, and ability to deliver repeatable motion control. Patient comfort, positioning and mobility, robotic surgery, imaging equipment, infusion, and pumping are just a few of the applications where the use of linear actuators has revolutionized the way medical devices are designed, improving patient outcomes and enhancing the overall quality of care
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