Browse Topic: Kinematics

Items (1,047)
Vehicle dynamics encompasses a vehicle’s motion along three principal axes: longitudinal, lateral, and vertical. The vertical component is particularly susceptible to vibrational forces that can impair passenger comfort and overall performance, and the suspension system filters these vibrations. Engineers and designers conduct various studies to enhance quality and develop innovative designs in this context. However, when it comes to military vehicles, this system is often treated as classified. Consequently, the proposed work aims to determine the parameters of this system for a wheeled military vehicle with four axles. To achieve this, a mathematical model is proposed utilizing the concepts of power flow and kinematic transformers through a modular system, intended to serve as the foundation for solving an inverse problem to identify these parameters. This approach employs two stochastic methods, particle swarm optimization (PSO) and differential evolution (DE), and field tests to
de Oliveira, André NoronhaBueno Caldeira, Aldélioda Costa Neto, Ricardo Teixeira
This paper presents a comprehensive overview of the methodology employed in leveraging CFD for optimizing HVAC kinematics, focusing on reducing the operating torque by improvising the flap geometry. The aim here is to utilize the CFD simulation in order to predict the torque generated on the actuator motor connected to the flap when the flap is placed in high speed airflow and based on this value work out an optimized geometry of the flap, since its geometry plays a significant role when it comes to determining the torque values. Different flap geometry imparts different torque on motor. This torque is generated because of the force acting on the flap which is acting as a buffer in the path of airflow. The torque generated should be less than the stall torque of the actuator motor in order for smooth performance/movement of the flap. Initial geometry of the flap generated a torque of around 82.5 Ncm which was much higher than the recommendation limit. So in order to bring these torque
Madaan, AshishKumar, RaviBehera, SureshChauhan, Arpit
In Automobile AC system, HVAC is one of major component as it controls the air flow and air distribution based on cabin requirement. HVAC kinematics mechanism is used for controlling the air flow based on passenger requirement inside the cabin. The air flow movement inside HVAC has a severe impact on servo motor/cable torque which is controlling the mechanism. Simulation driven design method is widely used in world due to highly competitive automotive industry. Launching the product at the market within short span of time, with good quality and less cost is more challenging. Hence CAE/MBD based approach is more significant as it will reduce number of prototypes as well as the cost of testing. The objective of the analysis is to predict the HVAC servomotor torque required to operate the HAVC linkages under operating conditions. The air pressure load will have significant impact on damper face which will cause torque at CAM as well as servo lever center. The torque values at servo lever
Parayil, Paulson
In the context of intelligent transportation systems and applications such as autonomous driving, it is essential to predict a vehicle’s immediate future states to enable precise and timely prediction of vehicles’ movements. This article proposes a hybrid short-term kinematic vehicle prediction framework that integrates a novel object detection model, You Only Look Once version 11 (YOLOv11), with an unscented Kalman filter (UKF), a reliable state estimation technique. This study provides a unique method for real-time detection of vehicles in traffic scenes, tracking and predicting their short-term kinematics. Locating the vehicle accurately and classifying it in a range of dynamic scenarios is achievable by the enhanced detection capabilities of YOLOv11. These detections are used as inputs by the UKF to estimate and predict the future positions of the vehicles while considering measurement noise and dynamic model errors. The focus of this work is on individual vehicle motion prediction
Pahal, SudeshNandal, Priyanka
This paper presents a methodology for optimizing the steering system of a multi-purpose agricultural vehicle (MPAV) equipped with four-wheel steering (4WS) and a symmetrically configured double-wishbone suspension on both axles. The MPAVs are often prone to bump steer issues due to their narrow track width and the need for long suspension travel. The objective is to define and dimension the steering geometry while maintaining the existing suspension kinematics and preserving the hard points of the wheel hubs. In the scientific literature, this issue is typically addressed by adjusting the hard points of both the steering mechanism and the suspension kinematics. The proposed optimization framework begins with a sensitivity analysis of key design parameters: the position and length of the steering actuator. Based on this analysis, the problem is formulated as an optimization task with two different objective functions, whose solutions are then compared. The functions aim to minimize bump
Belloni, MattiaVignati, MicheleSabbioni, Edoardo
Armored vehicles offer limited view to the driver and crew. Two-dimensional vision-based situational awareness (SA) systems provide the driver a view of the area around the vehicle. The addition of distance to objects can offer a more comprehensive understanding of the surroundings assisting the driver with the locations of obstacles and rollover hazards. Methods currently available or under development for depth perception have issues limiting their utility in the field.. Some interfere with crew operations, others are are too costly, are not covert or require excessive processing. We offer a low-cost and computationally efficient approach called Kinetically Enhanced Situational Awareness (KESA) that derives distance to objects using existing SA sensors and processors combined with a knowledge of vehicle kinematics. We demonstrate how range can be used to enhance and supplement AI based driver assistance and threat warnings.
Pilgrim, Robert A.Brown, Roy C.
Innovators at NASA Johnson Space Center have developed a programmable steering wheel called the Tri-Rotor, which allows an astronaut the ability to easily operate a vehicle on the surface of a planet or moon despite the limited dexterity of their spacesuit. This technology was originally conceived for the operation of a lunar terrain vehicle (LTV) to improve upon previous Apollo-era hand controllers. In re-evaluating the kinematics of the spacesuit, such as the rotatable wrist joint and the constant volume shoulder joint, engineers developed an enhanced and programmable hand controller that became the Tri-Rotor.
Trajectory planning is a major challenge in robotics and autonomous vehicles, ensuring both efficient and safe navigation. The primary objective of this work is to generate an optimal trajectory connecting a starting point to a destination while meeting specific requirements, such as minimizing travel distance and adhering to the vehicle’s kinematic and dynamic constraints. The developed algorithms for trajectory design, defined as a sequence of arcs and straight segments, offer a significant advantage due to their low computational complexity, making them well-suited for real-time applications in autonomous navigation. The proposed trajectory model serves as a benchmark for comparing actual vehicle paths in trajectory control studies. Simulation results demonstrate the robustness of the proposed method across various scenarios.
Soundouss, HalimaMsaaf, MohammedBelmajdoub, Fouad
Recent studies have found that Brain Injury Criteria (BrIC) grossly overpredicts instances of real-world, severe traumatic brain injury (TBI). However, as it stands, BrIC is the leading candidate for a rotational head kinematics-based brain injury criteria for use in automotive regulation and general safety standards. This study attempts to understand why BrIC overpredicts the likelihood of brain injury by presenting a comprehensive analysis of live primate head impact experiments conducted by Stalnaker et al. (1977) and the University of Pennsylvania before applying these injurious conditions to a finite element (FE) monkey model. Data collection included a thorough analysis and digitization of the head impact dynamics and resulting pathology reports from Stalnaker et al. (1977) as well as a representative reconstruction of the Penn II baboon diffuse axonal injury (DAI) model. Computational modeling techniques were employed on a FE Rhesus monkey model, first introduced by Arora et al
Demma, Dominic R.Tao, YingZhang, LiyingPrasad, Priya
This research article assesses the used motor oil’s (UMO) regeneration efficiency of a synthetic type X zeolite (siliceous fly ash–based) alone and combined with other adsorbents (composite adsorbents), namely activated carbon, bentonite, and acid-activated bentonite from Goshica’s (Kosovo) region. The UMO treated with the regenerating mixes has run about 20,000 km. Parameters including density, kinematic viscosity, viscosity index, pour point, and sulfur content were measured in the untreated and treated UMO and compared to those of the reference oil with additives of type SAE 5W-30. All regeneration mixes showed good regeneration efficiency, restoring the UMO’s parameters to almost the original ones of the reference oil with additives (SAE 5W-30). Only the zeolite alone could significantly reduce the sulfur content (removal efficiency 60%). This method deserves further investigation and with some improvements, it can be established as a reliable regeneration method for some UMO.
Korpa, ArjanDervishi, SaraGecaj, DianaShahu, KristiShehu, AlmaNuro, Aurel
Bicycle computers record and store kinematic and physiologic data that can be useful for forensic investigations of crashes. The utility of speed data from bicycle computers depends on the accurate synchronization of the speed data with either the recorded time or position, and the accuracy of the reported speed. The primary goals of this study were to quantify the temporal asynchrony and the error amplitudes in speed measurements recorded by a common bicycle computer over a wide area and over a long period. We acquired 96 hours of data at 1-second intervals simultaneously from three Garmin Edge 530 computers mounted to the same bicycle during road cycling in rural and urban environments. Each computer recorded speed data using a different method: two units were paired to two different external speed sensors and a third unit was not paired to any remote sensors and calculated its speed based on GPS data. We synchronized the units based on the speed signals and used one of the paired
Booth, Gabrielle R.Siegmund, Gunter P.
SAE J3230 provides Kinematic Performance Metrics for Powered Standing Scooters. These performance metrics include many tests which require specific conditions including flat pavement with a near zero slope, drivers of specific height and weights, and data acquisition equipment. In order to determine the efficacy of replicating SAE J3230 tests in a laboratory setting, a device called the Micromobility Device Thermo-Electric Dynamometer was used alongside outdoor tests to provide a comparison of scooter performance in these two testing applications. Based on the testing outcomes, it can be determined whether SAE J3230 and similar standards for other micromobility devices can be replicated in a lab-based setting, saving time, operator hazard, and providing more thorough data outputs.
Bartholomew, MeredithAndreatta, DaleZagorski, ScottHeydinger, Gary
To ensure the safety and stability of road traffic, autonomous vehicles must proactively avoid collisions with traffic participants when driving on public roads. Collision avoidance refers to the process by which autonomous vehicles detect and avoid static and dynamic obstacles on the road, ensuring safe navigation in complex traffic environments. To achieve effective obstacle avoidance, this paper proposes a CL-infoRRT planning algorithm. CL-infoRRT consists of two parts. The first part is the informed RRT algorithm for structured roads, which is used to plan the reference path for obstacle avoidance. The second part is a closed-loop simulation module that incorporates vehicle kinematics to smooth the planned obstacle avoidance reference path, resulting in an executable obstacle avoidance trajectory. To verify the effectiveness of the proposed method, four static obstacle test scenarios and four RRT comparison algorithms were designed. The implementation results show that all five
Wu, WeiLu, JunZeng, DequanYang, JinwenHu, YimingYu, QinWang, Xiaoliang
This paper investigates a novel seating arrangement where occupants face each other, focusing on occupant safety during a 56 km/h frontal impact, a standard test condition for assessing crashworthiness. A preliminary study was carried out, examining three distinct cases: a forward-facing 50th percentile occupant in third row seat, a rear-facing 50th percentile occupant in second row seat, and the interaction between these two occupant orientations. The study utilized both elastic flexible and rigid seat designs to analyze the impact on occupant kinematics and injury outcomes. The results demonstrate that the seating position has a significant influence on occupant injuries. Rear-facing occupants are primarily at risk due to seat design, whereas forward-facing occupants face a higher risk of injury from the increased space between occupants, lacking a reactive surface to mitigate impact forces. Notably, direct interaction between occupants did not result in severe injuries. However
Liu, ChongLi, KunLiu, YutaoLv, XiaojiangWang, YonghuiZhou, DayongYang, Heping
With the increasing adoption of Zero-Gravity Seats in intelligent cockpits, there is a growing concern over the safety of occupants in reclined postures during collisions. The newly released anthropomorphic test device (ATD), THOR-AV, has modified the neck, spine, and pelvis structures to better match reclined postures. This study aims to investigate the changes in kinematic response and injury metrics for occupants in reclined postures, through high-speed frontal sled tests utilizing the THOR-AV. The tests were conducted using an adjustable rigid seat with a zero-gravity characteristic and an integrated three-point seat belt. Six tests were performed across four seat configurations: Standard, Semi-Reclined, Reclined, and Zero-gravity postures. The input acceleration pulse for these tests was derived from the equivalent double trapezoidal waveform of the Mobile Progressive Deformable Barrier (MPDB) test. Data from sensors and high-speed video were collected for analysis. The results
Wang, QiangLiu, YuFei, JingYang, XiaotingWang, PeifengBai, Zhonghao
Plasticized polyvinyl chloride (PVC) has many applications in automotive industry including electrical harnesses, door handles, seat and head rest covers, and instrument panel (IP) and other interior trim. In IP applications, the PVC skin plays a critical role in passenger airbag deployment (PAB) by tearing along the scored edge of the PAB door and allowing the door to open and the airbag to inflate to protect the occupant. As part of the IP, the PVC skin may be exposed to elevated temperatures and ultraviolet (UV) radiation during the years of the vehicle life cycle which can affect the PVC material properties over time and potentially influence the kinematics of the airbag deployment. Chemical and thermal aging of plasticized PVC materials have been studied in the past, yet no information is found on how the aging affects mechanical properties at high rates of loading typical for airbag deployment events. This paper compares mechanical properties of the virgin PVC-based IP skin
G, KarthiganSavic, VesnaRavichandran, Gowrishankar
This paper seeks to define an analytical approach to ergonomic cockpit design for SAE formula style vehicles. The proposed approach uses a data driven driver model based on RAMSIS ergonomic FEA that considers the discomfort, fatigue, and force availability to evaluate cockpit designs that are generated considering defined constraint inputs, such as driver gender and size. The multifunctional model is applicable to various settings of vehicle design and is tuned toward proving performance in operation tasks, as well as setting the groundwork for a multi-variable optimization to determine the preferred driver controls positions for minimum effort and fatigue. In this initial research, RAMSIS ergonomic software is used to generate fatigue and joint discomfort data related to individual joint angles. Anthropometric data is used to calculate the proportional limb lengths from an individual’s gender and height percentile. The optimization function works by selecting a range of driver
Mayor, J.RhettBezaitis, MeganOromi, NegarWinters, EmilyRepp, Alex
In sheet metal simulation, computation time is significantly influenced by the number of elements used to discretize the sheet blank, which covers the shape of forming tool geometry. Based on particle kinematics, motion of material point is modeled, and the concept of zero circumferential motion material line (ZML) is proposed. The slope ratio of material line (SRML) is proposed to quantify the circumferential deviation for determining the ZML. Based on the SRML, a method is developed to segment sheet blank and apply constraints. The method is demonstrated through forming simulation on a Hishida geometry. The proposed method, with its minimal to no circumferential motion along ZMLs, exhibits high level of accuracy retention while simultaneously impressively reducing computation time (up to 77%). This combination of efficiency and precision makes it a compelling approach for reducing simulation cost.
Sheng, ZiQiangAsimba, BrianCabral, Kleber
During a pitch-over event, the forward momentum of the combined bicycle and rider is suddenly arrested causing the rider and bicycle to rotate about the front wheel and also possibly propelling the rider forward. This paper examines the pitch-over of a bicycle and rider using two methods different from previous approaches. One method uses Newton’s 2nd Law directly and the other method uses the principle of impulse and momentum, the integrated form of Newton’s 2nd Law. The two methods provide useful equations, contributing to current literature on the topic of reconstructing and analyzing bicycle pitch-over incidents. The analysis is supplemented with Madymo simulations to evaluate the kinematics and kinetics of the bicycle and rider interacting with front wheel obstructions of different heights. The effect of variables such as rider weight, rider coupling to the bicycle, bicycle speed, and obstruction height on resulting kinematics were evaluated. The analysis shows that a larger
Brach, R. MatthewKelley, MireilleVan Poppel, Jon
Many methods have been proposed to accurately compute a vehicle’s dynamic response in real-time. The semi-recursive method, which models using relative coordinates rather than dependent coordinates, has been proven to be real-time capable and sufficiently accurate for kinematics. However, not only kinematics but also the compliance characteristics of the suspension significantly impact a vehicle’s dynamic response. These compliance characteristics are mainly caused by bushings, which are installed at joints to reduce vibration and wear. As a result, using relative or joint coordinates fails to account for the effects of bushings, leading to a lack of compliance characteristics in suspension and vehicle models developed with the semi-recursive method. In this research, we propose a data-driven approach to model the compliance characteristics of a double wishbone suspension using the semi-recursive method. First, we create a kinematic double wishbone suspension model using both the semi
Zhang, HanwenDuan, YupengZhang, YunqingWu, Jinglai
The rapid advancement of inland waterway transport has led to safety concerns, while real-time high-precision positioning in maritime contexts is essential for enhancing navigation efficiency and safety. To tackle this problem, this paper proposes a method for enhancing the accuracy of maritime Real - Time Kinematic (RTK) positioning using smartphones based on multi-epoch elevation constraints. Firstly, the elevation characteristics of smartphones in a maritime context were analyzed. Subsequently, exploiting the feature of gradual elevation variations when vessels navigate inland rivers, an appropriate sliding window was established to construct elevation constraint values, which were then integrated into the observation equations for filtering computations to boost positioning accuracy. Finally, synchronous observations were carried out using smartphones and geodetic receivers to compare and analyze the positioning accuracy before and after the addition of the elevation constraints
Wumaier, DiliyaerYu, XianwenMu, Hongbo
Seventeen research posters were prepared and presented by student authors. The posters covered a wide breadth of works-in-progress and recently completed projects. Topics included a variety of body regions and injury scenarios: Biofidelity Corridors of Powered Two-Wheeler Rider Kinematics from Full-Scale Crash Testing Using Postmortem Human Subjects, Meringolo et al. Cervical Vertebral and Spinal Cord Injuries Remain Overrepresented in Rollover Occupants, Al-Salehi et al. The Effect of Surfaces on Knee Biomechanics during a 90-Degree Cut, Rhodes et al. Investigating the Variabilities in the Spinal Cord Injury in Pig Models Using Benchtop Test Model and Ultrasound Analyses, Borjali et al. Relationship between Tackle Form and Head Kinematics in Youth Football, Holcomb et al. Comparing Motor Vehicle Collision Injury Incidence between Pregnant and Nonpregnant Individuals: A Case–Control Study, Levine et al. Development of an Automated Pipeline to Characterize Full Rib Cage Shape
Bautsch, Brian T.Cripton, Peter A.Cronin, Duane
Ongoing research in simulated vehicle crash environments utilizes postmortem human subjects (PMHS) as the closest approximation to live human response. Lumbar spine injuries are common in vehicle crashes, necessitating accurate assessment methods of lumbar loads. This study evaluates the effectiveness of lumbar intervertebral disc (IVD) pressure sensors in detecting various loading conditions on component PMHS lumbar spines, aiming to develop a reliable insertion method and assess sensor performance under different loading scenarios. The pressure sensor insertion method development involved selecting a suitable sensor, using a customized needle-insertion technique, and precisely placing sensors into the center of lumbar IVDs. Computed tomography (CT) scans were utilized to determine insertion depth and location, ensuring minimal tissue disruption during sensor insertion. Tests were conducted on PMHS lumbar spines using a robotic test system for controlled loading in flexion
Burns, Michael R.Caldwell, A. JamesShin, JeesooSochor, Sara H.Kopp, Kevin P.Shaw, GregGepner, BronislawKerrigan, Jason R.
Extreme out-of-position pre-crash postures may need high-force pre-pretensioner (PPT) for effective repositioning (Mishra et al., 2023). To avoid applying a high force on the chest, we hypothesized that in case of these extreme postures the PPT may be activated in the absence of a pre-crash motion as a cautionary measure. Therefore, the aims of this study were: (1) to understand the effect of the PPT in repositioning a forward-leaning occupant in static conditions and (2) to characterize occupants’ kinematic variability during repositioning. Sixteen healthy volunteers (8 males, 8 females, 23.8 ± 4.2 years old) were seated with a 40° forward posture on a vehicle seat and restrained with a 3-point seat belt equipped with a PPT. Two PPT seatbelt conditions were examined: low PPT (100 N) and high PPT (300 N). Head and trunk rearward displacements relative to the initial forward-leaning position at 350 ms from PPT onset were collected with a 3D motion-capture system and compared between
Witmer, MaitlandGriffith, MadelineGraci, Valentina
Athletes may sustain numerous head impacts during sport, leading to potential neurological consequences. Wearable sensors enable real-world head impact data collection, offering insight into sport-specific brain injury mechanisms. Most instrumented mouthguard studies focus on a single sport, lacking a quantitative comparison of head impact biomechanics across sports. Additionally, direct comparison of prior studies can be challenging due to variabilities in methodology and data processing. Therefore, we gathered head impact data across multiple sports and processed all data using a uniform processing pipeline to enable direct comparisons of impact biomechanics. Our aim was to compare peak kinematics, impulse durations, and head impact directionality across ice hockey, American football, rugby, and soccer. We found that American football had the highest magnitude of head impact kinematics and observed directionality differences in linear and angular kinematics between sports. On the
Masood, Zaryan Z.Luke, David S.Kenny, Rebecca A.Bondi, Daniel R.Clansey, Adam C.Wu, Lyndia C.
Head injuries account for 15% of snowsport-related injuries, and the majority of head impacts occur against ice or snow, low-friction surfaces. Therefore, this study aimed to evaluate how surface friction affects snowsport helmets’ oblique impact kinematics. Ten helmet models were impacted using an oblique drop tower with a 45-degree anvil and NOCSAE headform, at three locations, two surface friction conditions, and a drop speed of 5.0 m/s. Our findings indicate that friction affects peak linear acceleration, peak rotational acceleration, and peak rotational velocity during helmet impacts, with changes in post-impact rotation and impact response varying by location. Surface friction affects head impact kinematics, underscoring the need for sport-specific lab testing and emphasizing the need for friction-specific and sport-specific testing, particularly for snowsports, where surface conditions like snow and ice can alter kinematics.
Stark, Nicole E.-P.Calis, AndrewWood, MatthewPiwowarski, Summer BlueDingelstedt, KristinBegonia, MarkRowson, Steve
Mitigating both neck and head injuries in the pediatric population relies heavily on improving our understanding of the underlying biomechanics of the pediatric cervical spine. The tensile response for individual motion segments and the whole cervical spine (WCS) has been reported, but there is no data characterizing the intersegmental kinematics of pediatric WCS under axial loading conditions. The structural response of motion segments and WCS provide valuable data for the design and validation of biofidelic physical and computational models for the pediatric population. However, the use of motion segment data to construct WCS response or the use of WCS axial response to accurately characterize intersegmental response may present limitations to accurately modeling the pediatric cervical spine response. In this secondary analysis of the work of Luck et al. (2008, 2013), the fixed-fixed, low load, quasi-static tensile response of the WCS and individual motion segments (O-C2, C4-C5, and
Liu, MirandaLuck, Jason F.
The increased use of computational human models in evaluation of safety systems demands greater attention to selected methods in coupling the model to its seated environment. This study assessed the THUMS v4.0.1 in an upright driver posture and a reclined occupant posture. Each posture was gravity settled into an NCAC vehicle model to assess model quality and HBM to seat coupling. HBM to seat contact friction and seat stiffness were varied across a range of potential inputs to evaluate over a range of potential inputs. Gravity settling was also performed with and without constraints on the pelvis to move towards the target H-Point. These combinations resulted in 18 simulations per posture, run for 800 ms. In addition, 5 crash pulse simulations (51.5 km/h delta V) were run to assess the effect of settling time on driver kinematics. HBM mesh quality and HBM to seat coupling metrics were compared at kinetically identical time points during the simulation to an end state where kinetic
Wade von Kleeck, B.Caffrey, JulietteWeaver, Ashley A.Gayzik, F. ScottHallman, Jason
In the 1990s and early 2000s, the field of parallel kinematics was viewed as being potentially transformational in manufacturing, having multiple potential advantages over conventional serial machine tools and robots. Many prototypes were developed, and some reached commercial production and implementation in areas such as hard material machining and particularly in aerospace manufacturing and assembly. There is some activity limited to niche and specialist applications; however, the technology never quite achieved the market penetration and success envisaged. Yet, many of the inherent advantages still exist in terms of stiffness, force capability, and flexibility when compared to more conventional machine structures. This chapter will attempt to identify why parallel kinematic machines (PKMs) have not lived up to the original excitement and market interest and what needs to be done to rekindle that interest. In support of this, a number of key questions and issues have been identified
Muelaner, JodyWebb, Philip
There is little prior research into chain-collisions, despite their relatively large contribution to injury and harm in motor-vehicle collisions. This study conducted a series of rear-impact, front-impact, and chain-collision impacts using a bumper car ride at an active amusement park as a proxy for automobiles. The purpose was to begin to identify the threshold time range when separate, discrete collisions transition into a hybrid or combined chain-collision mode and provide bases for future analyses. The test series consisted of rear impacts into an occupied target vehicle from a driven bullet vehicle; frontal impacts into a perimeter barrier (wall); chain-collisions consisting of a driven bullet vehicle striking an occupied primary target vehicle, which then collided with a non-occupied secondary target vehicle; and chain-collisions consisting of a driven bullet vehicle striking an occupied primary target vehicle which then collided with a wall. Time between collisions was adjusted
Bussone, William R.Koiler, RezaBenda, JamieCarney, NicholasGeffard, AndresSam, Samantha
Due to the lack of biofidelity seen in GHBMC M50-O in rear-facing impact simulations involving interaction with the seat back in an OEM seat, it is important to explore how the boundary conditions might be affecting the biofidelity and potentially formulate methods to improve biofidelity of different occupant models in the future while also maintaining seat validity. This study investigated the influence of one such boundary condition, which is the seat back foam material properties, on the thorax and pelvis kinematics and injury outcomes of the GHBMC 50th M50-O model in a high-speed rear-facing frontal impact scenario, which involves severe occupant loading of the seat back. Two different seat back foam materials were used – a stiff foam with high densification and a soft foam with low densification. The peak magnitudes of the T-spine resultant accelerations of the GHBMC M50-O increased with the use of soft foam as compared to stiff foam. However, the change in the average biofidelity
Pradhan, VikramRamachandra, RakshitKang, Yun Seok
Driver Assistance and Autonomous Driving features are becoming nearly ubiquitous in new vehicles. The intent of the Driver Assistant features is to assist the driver in making safer decisions. The intent of Autonomous Driving features is to execute vehicle maneuvers, without human intervention, in a safe manner. The overall goal of Driver Assistance and Autonomous Driving features is to reduce accidents, injuries, and deaths with a comforting driving experience. However, different drivers can react differently to advanced automated driving technology. It is therefore important to consider and improve the adaptability of these advances based on driver behavior. In this paper, a human-centric approach is adopted to provide an enriching driving experience. We perform data analysis of the naturalistic behavior of drivers when performing lane change maneuvers by extracting features from extensive Second Strategic Highway Research Program (SHRP2) data of over 5,400,000 data files. First, the
Lakhkar, Radhika AnandraoTalty, Tim
Innovators at NASA Johnson Space Center have developed a programmable steering wheel called the Tri-Rotor, which allows an astronaut the ability to easily operate a vehicle on the surface of a planet or Moon despite the limited dexterity of their spacesuit. This technology was originally conceived for the operation of a lunar terrain vehicle (LTV) to improve upon previous Apolloera hand controllers. In re-evaluating the kinematics of the spacesuit, such as the rotatable wrist joint and the constant volume shoulder joint, engineers developed an enhanced and programmable hand controller that became the Tri-Rotor.
Increasing the degree of individuality of the autopilot and adapting it to the habits of drivers with different driving styles will help to increase occupant acceptance of the autopilot function. Inspired by the Twin Delayed Deep Deterministic policy gradient algorithm(TD3) algorithm to increase action spontaneity, this paper proposes a Soft Actor-Critic(SAC) based personalized following control strategy to increase the degree of strategy personalization through driver data. In order to obtain real driver data, this paper collected driving data based on driver-in-the-loop experiments conducted on a simulated driving platform, and selected data from three drivers with distinctive driving characteristics for model training. A continuous action space model was developed by vehicle following kinematics. A temporal Gate Recurrent Unit (GRU) based reference model is trained to receive temporal state signals and output acceleration actions according to the current state. In this paper, we
Wu, MingzhiYu, QinHu, YimingLiu, Xuegao
Sustainable transportation has been a focus area for over a decade, and the recent pandemic-induced lockdowns have witnessed a substantial increase in the demand for fitness equipment. Several studies have proposed different techniques for harvesting energy from human motion, such as piezoelectric footwear, backpacks, and wearable lightweight systems. This research aims to develop a low-cost and efficient technique for harvesting energy from a custom-built electric bike that can be used as a stationary exercise bike. Integrating electric bicycles as exercise bikes has become a viable solution to promote physical fitness and environmental responsibility. This technical paper explores the mechanical and electrical design of e-bikes as exercise bikes and the technical considerations required to create a functional and efficient hybrid machine. The technical aspects of integrating an electric bicycle with an exercise bike include modifying the frame to allow for a stationary position using
P R, BharanitharanAnbalagan, RajalakshmiMani, ThanigaivelArumugam, Velmurugan
In this paper, semi-active MR main suspension system based on system controller design to minimize pitch motion linked with MR-controlled seat suspension by considering driver’s biodynamics is investigated. According to a fixed footprint tire model, the transmitted tire force is determined. The linear-quadratic Gaussian (LQG) system controller is able to enhance ride comfort by adjusting damping forces based on an evaluation of body vibration from the dynamic responses. The controlled damping forces are tracked by the signum function controllers to evaluate the supply voltages for the front and rear MR dampers. Based on the sprung mass acceleration level and its derivative as the inputs, the optimal type-2 (T-2) fuzzy seat system controller is designed to regulate the controlled seat MR damper force. The best rate for each linguistic variable is acquired by modifying the range between upper and lower membership functions (MFs), which enables accurate tracking of the seat-damping force
Shehata Gad, Ahmed
Pyrotechnic seat belt pretensioners typically remove 8–15 cm of belt slack and help couple an occupant to the seat. Our study investigated pretensioner deployment on forward-leaning, live volunteers. The forward-leaning position was chosen because research indicates that passengers frequently depart from a standard sitting position. Characteristics of the 3D kinematics of forward-leaning volunteers following pretensioner deployment determines if body size is correlated with subject response. Nine adult subjects (three female), ages 18–43 years old, across a wide range of body sizes (50–120 kg) were tested. The age was limited to young, active adults as pyrotechnic pretensioners can deliver a notable force to the trunk. Subjects assumed a forward-leaning position, with 26 cm between C7 and the headrest, in a laboratory setting that replicated the passenger seat of a vehicle. At an unexpected time, the pretensioner was deployed. 3D kinematics were measured through a nine-camera motion
Hellenbrand, CiboneyBrown, J. FletcherGoodworth, Adam
Computational and experimental studies have been undertaken to investigate injurious head-first impacts (HFI), which can occur during automotive rollovers. Recent studies assume a torso surrogate mass (TSM) boundary condition, wherein the first or first two thoracic vertebrae are potted and constrained to only move in the vertical loading direction. The TSM boundary condition has not been compared with a full body (FB) model computationally or experimentally for HFI. In this study, the Global Human Body Models Consortium 50th percentile male detailed human body model (M50-O, Version 6.0) was applied to compare the kinematic, kinetic, and injury response of an HFI with a TSM boundary condition (M50-TSM), and a full body boundary condition (M50-FB). Impacts (to M50-TSM and M50-FB) were simulated between the head and a rigid plate using a commercial FE code (LS-DYNA). The impact velocity of 3.1 m/s corresponded to the onset of spinal injury in diving reconstructions, and the impact
Morgan, M.I.Corrales, M.Cripton, P.Cronin, D.S.
Parking an articulated vehicle is a challenging task that requires skill, experience, and visibility from the driver. An automatic parking system for articulated vehicles can make this task easier and more efficient. This article proposes a novel method that finds an optimal path and controls the vehicle with an innovative method while considering its kinematics and environmental constraints and attempts to mathematically explain the behavior of a driver who can perform a complex scenario, called the articulated vehicle park maneuver, without falling into the jackknifing phenomena. In other words, the proposed method models how drivers park articulated vehicles in difficult situations, using different sub-scenarios and mathematical models. It also uses soft computing methods: the ANFIS-FCM, because this method has proven to be a powerful tool for managing uncertain and incomplete data in learning and inference tasks, such as learning from simulations, handling uncertainty, and
Rezaei Nedamani, HamidrezaSoleymanifard, MostafaSafaeifar, AliKhiabani, Parisa Masnadi
Previous volunteer studies focused on low-speed frontal events have demonstrated that muscle activation (specifically pre-impact bracing) can significantly affect occupant response. However, these tests do not always include a sufficient number of small female volunteers to compare their unique responses to the typically studied midsize male population. The purposes of this study were to quantify the occupant kinetics and muscle responses of relaxed and braced small female and midsize male volunteers during low-speed frontal sled tests and to compare between muscle states and demographic groups. Small female and midsize male volunteers experienced multiple low-speed frontal sled tests consisting of two pulse severities (1 g and 2.5 g) and two muscle states (relaxed and braced) per pulse severity. The muscle activity of 30 muscles (15 bilaterally) and reaction forces at the volunteer-test buck interfaces and seat belt were measured before and during each sled test. Compared to the
Chan, HanaAlbert, Devon L.Gayzik, F. ScottKemper, Andrew R.
The reality of the autonomous vehicle in a near future is growing and is expected to induce significant change in the occupant posture with respect to a standard driving posture. The delegated driving would allow sleeping and/or resting in a seat with a reclined posture. However, the data in the literature are rare on the body kinematics, human tolerance, and injury types in such reclined postures. The current study aims at increasing the knowledge in the domain and providing useful data to assess the relevance of the standard injury assessment tools such as anthropomorphic test devices or finite element human body models. For that purpose, a test series of three male Post-Mortem Human Subjects (PMHS) were performed in frontal impact at a 13.4 m/s delta V. The backseat inclination was 58 degrees with respect to the vertical axis. The semi-rigid seat developed by Uriot et al. (2015) was used with a stiffer seat ramp. The restraint was composed of a lap belt equipped with two 3.5 kN load
Baudrit, PascalUriot, JérômeRichard, OlivierDebray, Matthieu
Traumatic brain injury (TBI) is the leading cause of death and long-term disability in road traffic accidents (RTAs). Researchers have examined the effect of vehicle front shape and pedestrian body size on the risk of pedestrian head injury. On the other hand, the relationship between vehicle front shape parameters and pedestrian TBI risks involving a diverse population with varying body sizes has yet to be investigated. Thus, the purpose of this study was to comprehensively study the effect of vehicle front shape parameters and various pedestrian bodies ranging from 95th percentile male (AM95) to 6 years old (YO) child on the dynamic response of the head and the risk of TBIs during primary (vehicle) impact. At three different collision speeds (30, 40, and 50 km/h), a total of 36 car-to-pedestrian collisions (CPCs) were reconstructed using three different vehicle types (Subcompact passenger sedan, mid-sedan, and sports utility vehicle (SUV)) and four distinct THUMS pedestrian finite
Gunasekaran, KalishIslam, Sakib UlMao, Haojie
This document establishes acceptable design criteria for instrument and cockpit illumination for general aviation aircraft.
A-20A Crew Station Lighting
This standard covers the general requirements and methods for testing sandwich core materials and for testing sandwich construction of the types used primarily in aircraft structures. This standard does not include test methods applicable only to a specific product; such test methods are included in the detailed specifications for the product.
AMS P17 Polymer Matrix Composites Committee
Ride comfort improvement and motion sickness reduction are gaining attention given recent technological trends, such as the advancement of automated driving systems, the introduction of in-vehicle digital devices, and the daily use of mobile devices in vehicles. As a countermeasure, mathematical models predicting motion sickness were proposed. Among them, models based on sensory conflict or subjective vertical conflict theories were developed. These models can successfully describe the tendency of motion sickness in several scenarios involving various vestibular inputs or head movements, including carsickness. Almost all models are based on human motion perception with an internal model hypothesis. It has advantages when expanded to model sickness caused by multi-sensory inputs. Some expansions of the models to include the effects of visual information and motion prediction on motion sickness have been made. However, the motion perception calculated by the models has not been
Inoue, ShotaLiu, HailongWada, Takahiro
Bushing elasticity is one of the most important compliance factors that significantly influence driving behavior. The deformations of the bushings change the wheel orientations under external forces. Another important factor of bushing compliance is to provide a comfortable driving experience by isolating the vibrations from road irregularities. However, the driving comfort and driving dynamics are often in conflict and need to be balanced in terms of bushing compliance design. Specifically, lateral force steer and brake force steer are closely related to safety and stability and comprises must be minimized. The sensitivity analysis helps engineers to understand the critical bushing for certain compliance attributes, but optimal balancing is complicated to understand. The combination of individual bushing stiffness must be carefully set to achieve an acceptable level of all the attributes. Traditional bushing tuning method involves an optimization process in Adams Car or any other
Naik, AkshayBrandin, TobiasHuang, YansongJacobson, Bengt
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