Test Dummy Research Articles

Comparison of the Injury Mechanism between Pregnant and Non-Pregnant Women Vehicle Passengers Using Car Crash Test Dummies.

This paper analyzes the kinematics and applied forces of pregnant and non-pregnant women dummies sitting in the rear seat during a frontal vehicle collision to determine differences in the features of abdominal injuries. Sled tests were conducted at 29 and 48 km/h with pregnant and non-pregnant dummies (i.e., MAMA IIB and Hybrid III). The overall kinematics of the dummy, resultant acceleration at the chest, transrational acceleration along each axis at the pelvis, and loads of the lap belt and shoulder belt were examined. The belt loads were higher for the MAMA IIB than for the Hybrid III because the MAMA IIB had a higher body mass than the Hybrid III. The differences in the lap belt loads were 1119 N at 29 km/h and 1981–2365 N at 48 km/h. Therefore, for restrained pregnant women sitting in the rear seat, stronger forces may apply to the lower abdomen during a high-velocity frontal collision. Our results suggest that for restrained pregnant women sitting in the rear seat, the severity of abdominal injuries and the risk of a negative fetal outcome depend on the collision velocity.

Safety analysis of adapted battery-powered ride-on toy car for children with disabilities using a modified test dummy with varying joint stiffness

ABSTRACT Adaptive ride-on toy programs have increased in popularity in recent years and provide novel rehabilitation tools as developmental aids for children with disabilities. While the adaptations made to these toys are intended to provide a safer experience for children with disabilities, safety concerns still exist. Within this context, the purpose of this study was to use a model with varying joint stiffness as a first-order approximation of a child with disabilities and to investigate whether modifications to ride-on toys are sufficient to prevent common injuries. Because the population of children with disabilities who are receiving adaptive ride-on toys have a wide range of musculoskeletal disorders, those with both decreased and increased muscle stiffness were considered in this safety study. A 5-point harness reduced movement regardless of change in joint stiffness and therefore, results from this study indicate that the use of these harnesses is effective regardless of joint stiffness. Furthermore, as excursion-related injuries are considered more critical to the user than injuries relating to kinetic variables and no known injury thresholds were exceeded, the addition of a belt is considered a necessary trade-off with little-to-no added risk.

Proposing an Uncertainty Management Framework to Implement the Evidence Theory for Vehicle Crash Applications

Abstract The purpose of this work is to enable the use of the Dempster–Shafer evidence theory (ET) for uncertainty propagation on computationally expensive automotive crash simulations. This is necessary as the results of these simulations are influenced by multiple possibly uncertain aspects. To avoid negative effects, it is important to detect these factors and their consequences. The challenge when pursuing this effort is the prohibitively high computational cost of the ET. To this end, we present a framework of existing methods that is specifically designed to reduce the necessary number of full model evaluations and parameters. An initial screening removes clearly irrelevant parameters to mitigate the curse of dimensionality. Next, we approximate the full-scale simulation using metamodels to accelerate output generation and thus enable the calculation of global sensitivity indices. These indicate effects of the parameters on the considered output and more profoundly sort out irrelevant parameters. After these steps, the ET can be performed rapidly and feasibly due to fast-responding metamodel and reduced input dimension. It yields bounds for the cumulative distribution function of the considered quantity of interest. We apply the proposed framework to a simplified crash test dummy model. The elementary effects method is used for screening, a kriging metamodel emulates the finite element simulation, and Sobol' sensitivity indices are determined before the ET is applied. The outcome of the framework provides engineers with information about the uncertainties they may face in hardware testing and that should be addressed in future vehicle design.

THOR 50th Dummy Neck Calibration Analysis Based on Bi-LSTM Neural Network

In this paper, a neural network model is established based on the neck calibration data of the Thor50th crash test dummy using a bi-directional long and short-term memory (Bi-LSTM) neural network algorithm. The model input is the factors affecting the neck calibration test, and the output is the maximum value of My in the neck calibration test, and the accuracy of the model is calibrated by comparing it with the actual calibration data. The accuracy and suitability of the Bi-LSTM neural network model is further verified by comparing with the radial basis (RBF) neural network algorithm.

Virtual Validation of Power and Force Limiting Setups in Human-Robot-Collaboration

Industrial applications with physical human-robot-interaction that rely on the application principal “Power and force limiting” require to verify the biomechanical load acting on the operator during a contact to ensure compliance with applicable standards. The related force and pressure measurements can only be carried out after a specific application is built up. Existing approaches to determine the biomechanical load range from simulations over setups with crash test dummies or biofidel measurement devices to studies with humans. Studies with humans are suited to define thresholds for biomechanical loads but not to verify them on a real application. To some extent, dynamic simulations can estimate the biomechanical load in unconstrained contact situations but are limited in case of constrained contacts. To fill this gap related to constrained contacts we propose a comprehensive approach for the planning of Power and force limiting in this paper. After giving an overview over existing testbeds for collision testing in human-robot-interaction, a new testbed setup is proposed as well as an approach to utilize the generated data to create benefits for end users of the tested robots. With this approach the collision-force and -pressure during a contact are estimated based on information that are available before the application is built up. An expert system gives advice to the user how to modify the application to meet design requirements and ensure operator safety. The proposed approach relies on an advanced testbed, which is able to reproduce representative contact situations between a human and a test-robot by varying the parameters: contact position and direction, velocity at the contact point, end-effector weight, collision surface and affected human body part. The testbed is implemented prototypically to investigate the feasibility of the approach. The biomechanical loads of reproduced contact situations are measured using a state-of-the-art biofidel measurement device and stored in a database, where they can be used to estimate the force and pressure of planned applications and create instructions to influence a desired application parameter.

Metodika získavania vonkajšej geometrie segmentov novej generácie skúšobnej figuríny

The article presents the fulfilment of a partial goal of the research project focused on developing and constructing a biofidelic surrogate of the human body to improve the forensic reconstruction of road traffic accidents. It aims to describe the methods and results of acquiring external geometry of segments of crash test dummy Hybrid III. To create a precise spatial representation of dummy segments, we applied 3D laser scanning using the handheld 3D scanner VIUscan Handyscan 3D. The workflow, used material and application of software support are closely described in the methodical part of the article. The results present 3D models of significant material for the continuous fulfilment of project goals. In the follow-up activities, we will use dummy external geometry data, particularly to develop molds for casting segments of new-generation synthetic human body surrogates.

Crash tests to evaluate the design of temporary traffic control devices for increased safety of cyclists at road works

In Sweden there is an on-going process to formulate a national standard regulating the design of temporary traffic control devices used on pedestrian and bicycle paths. This paper presents results from simulated single-bicycle crashes with the purpose to create an understanding of how different features of such devices affect the risk of injuries among cyclists. A Hybrid II 50th percentile crash test dummy was placed in the saddle of a bicycle and crash tests, usually at 25 km/h, were performed. Eleven different types of road equipment were included, and different crash angles were applied, in a total of over 50 crash tests. The road equipment represented temporary traffic control devices of various kind commonly used in Sweden, but also some specifically designed for cyclists. The tests were documented with several video cameras at different angles. Slow motion pictures were analyzed with focus on mechanisms during impact and the following motion of the bicycle and the dummy. Observations regarding “body parts” in contact with the road equipment were of particular interest highlighting design features of importance such as height, smoothness of surfaces and energy-absorbing capacity. The tests show that all bicycle crashes into road equipment can cause injuries and thus the use of work zone material on bicycle paths should be avoided, if possible. Safety barriers designated to prevent cyclists from falling into a shaft must be high enough to do so and be anchored and linked together correctly to prevent them from falling and creating dangerous situations. Temporary traffic control devices should be flexible or energy-absorbing to moderate the injury outcome of a potential bicycle crash. Fences should have a fine meshed net construction to prevent bicycle handlebars from getting stuck. All road equipment should be designed without sharp edges as they could cause injuries to cyclists passing or crashing into the equipment.

Motor Vehicle Crash Testing Regulations for More Inclusive Populations

There is a stark disparity in motor vehicle crash deaths and injuries between male and female drivers. Female drivers are 13% more likely to be killed than their male counterparts in similar motor accidents. However, vehicle safety test practices do not account for diverse body proportions when assessing safety outcomes. Vehicle crash testing standards only require testing of two variations of adult-sized crash test dummies: a 50th percentile male and a 5th percentile female. Automotive companies are not required to test safety outcomes in crash test model’s representative of average female proportions or of non-average body sizes and physiological compositions. Current crash test standards are regulated by the National Highway Traffic Safety Administration (NHTSA) under the US Department of Transportation. This memo proposes three actions for the NHTSA and the Department of Transportation to address disparities in vehicle safety outcomes: 1) update safety standard requirements to include a 50th percentile female crash test dummy, 2) implement a federal tax incentive program for companies to include a greater diversity of vehicle occupant models, and 3) allocate funds for research and development of virtual crash testing models. These proposed initiatives seek to raise the minimum safety requirements and prioritize wider representation of vehicle occupants to improve parity in vehicle safety outcomes.

ОЦЕНКА БЕЗОПАСНОСТИ ПАССАЖИРСКИХ ВАГОНОВ ПРИ АВАРИЙНОМ ОПРОКИДЫВАНИИ НА НАСЫПЬ

The purpose of the work is to assess the safety of passenger cars in case of an emergency rollover on the body of railroad tracks. The paper introduces a method for predicting injury of railway transport passengers as a result of swinging over the wagon on the body of railroad tracks. The method of research is mathematical modeling of scenarios of swinging over the wagon on a flat bottom or earth tramp of the railway track. A model of a passenger compartment has been developed, which is supplemented with models of a roomette, hand luggage and an anthropometric dummy. The originality of the work is the use of mannequin models for an accident with the rollover of a compartment car on the body of the railroad tracks and obtaining data on the interaction of fit models and a compartment car. The result of the study is the reported values of possible injury to passengers during an emergency rollover of a passenger car. Namely, the values of the head injury criterion, cervical vertebrae, breast and hips of the crash test dummy have been obtained. In comparison of the two considered scenarios of swinging over the wagon, the value of the head injury criterion for overturning the car on an inclined surface is 15% higher, the neck injury criterion is 30% higher, and the hip and chest injury criterion is 23% higher for mannequins on the upper shelves of the compartment due to their interaction with hand luggage. The obtained values do not exceed critical ones. The most dangerous positions of the mannequin model in the compartment of the car are revealed. Conclusions concerning the sufficient safety of the passenger car are formed and recommendations for the development of additional technical solutions to improve the safety of passenger cars are given.

Safe transport of spica casted infants: Reducing the risk of traumatic injury in side impact collisions

BackgroundThere is limited data on transporting small children in hip spica casts used to treat pediatric femur fractures. Specific challenges include the fixed position of the body in the casted position and the increased size of the child due to cast thickness. Additionally, children less than 2 years old are recommended to be rear facing during transportation. This traveling position requires seats that are specifically designed to accommodate the small size of the child as well as accommodate the rear facing position. While seats able to accommodate casted children are available, it is unclear if they provide adequate protection in side impact collisions for rear facing spica casted infants. Therefore, the aim of this study was to evaluate traumatic injury metrics in a side impact collision model where a spica casted infant crash dummy was restrained in currently available car seats. MethodsTwo seats designed for spica casted children (R82 Quokka, Merritt Wallenberg) and two traditional car seats (Britax Emblem, Graco Sequel) able to accommodate a casted one-year-old crash test dummy were identified. Side impact collision testing was performed with the dummy positioned in the rear facing position and injury metrics recorded. ResultsTesting identified contact between the dummy's head and the door panel for a specialty spica car seat without protective side-wings for the head. All other seats contained side wings and prevented door-head contact. ConclusionsCasted children should be transported in a seat able to accommodate the cast and safely restrain them. Our results demonstrate the importance of side wing protection in any seat used to transport these children as side bolsters may help decrease the potential for head contact with the door and lower the risk of severe head injury.

Design and Evaluation of the Initial 50th Percentile Female Prototype Rear Impact Dummy, BioRID P50F - Indications for the Need of an Additional Dummy Size.

The objective of this study was to present the design of a prototype rear impact crash test dummy, representing a 50th percentile female, and compare its performance to volunteer response data. The intention was to develop a first crude prototype as a first step toward a future biofidelic 50th percentile female rear impact dummy. The current rear impact crash test dummy, BioRID II, represents a 50th percentile male, which may limit the assessment and development of whiplash protection systems with regard to female occupants. Introduction of this new dummy size will facilitate evaluation of seat and head restraint (HR) responses in both the average sized female and male in rear impacts. A 50th percentile female rear impact prototype dummy, the BioRID P50F, was developed from modified body segments originating from the BioRID II. The mass and rough dimensions of the BioRID P50F is representative of a 50th percentile female. The prototype dummy was evaluated against low severity rear impact sled tests comprising six female volunteers closely resembling a 50th percentile female with regard to stature and mass. The head/neck response of the BioRID P50F prototype resembled the female volunteer response corridors. The stiffness of the thoracic and lumbar spinal joints remained the same as the average sized male BioRID II, and therefore likely stiffer than joints of an average female. Consequently, the peak rearward angular displacement of the head and T1, and the rearward displacement of the T1, were lesser for the BioRID P50F in comparison to the female volunteers. The biofidelity of the BioRID P50F prototype thus has some limitations. Based on a seat response comparison between the BioRID P50F and the BioRID II, it can be concluded that the male BioRID II is an insufficient representation of the average female in the assessment of the dynamic seat response and effectiveness of whiplash protection systems.

Time and temperature sensitivity of the hybrid III lumbar spine

Objective Researchers have found a variety of uses for the Hybrid III (HIII) dummy that fall beyond the scope of its original purpose as an automotive crash test dummy. Some of these expanded roles for the HIII introduce situations that were not envisioned in the dummy’s original design parameters, such as a relatively rapid succession of tests or outdoor testing scenarios where temperature is not easily controlled. This study investigates how the axial compressive stiffness of the HIII lumbar spine component is affected by the duration of the time interval between tests. Further, it measures the effect of temperature on the compressive stiffness of the lumbar spine through a range of temperatures relevant to indoor and outdoor testing. Methods High-rate axial compression tests were run on a 50th percentile male HIII lumbar component in a materials testing machine. To characterize the effects of tests recovery intervals, between-test recovery was varied from 2 hours to 1 minute. To quantify temperature effects, environmental temperature conditions of 12.5°, 25°, and 37.5 °C were tested. Results During repeated compressive loading, the force levels decreased consistently across long and short rest intervals. Even after 2 hours of rest between tests, full viscoelastic recovery was not observed. Temperature effects were pronounced, resulting in compressive force differences of 261% over the range of 12.5° to 37.5 °C. Compared to the stiffness of the lumbar at 25 °C, the stiffness at 37.5 °C fell by 40%; at 12.5 °C, the stiffness more than doubled, increasing by 115%. Conclusions A modest decrease in temperature can be sufficient to dramatically change the response and repeatability of the lumbar HIII component in compressive loading. The large magnitude of the temperature effect has severe implications in its ability to overwhelm the contributions of targeted test variables. These findings highlight the importance of controlling, monitoring and reporting temperature conditions during HIII testing, even in indoor laboratory environments.

Analysis of the Head of a Simulation Crash Test Dummy with Speed Motion

The article presents a model of an anthropometric dummy designed for low velocity crash tests, designed in ADAMS. The model consists of rigid bodies connected with special joints with appropriately selected stiffness and damping. The simulation dummy has the appropriate dimensions, shape, and mass of individual elements to suit a 50 percentile male. The purpose of this article is to draw attention to low speed crash tests. Current dummies such as THOR and Hybrid III are used for crash tests at speeds above 40 km/h. In contrast, the low-speed test dummy currently used is the BioRID-II dummy, which is mainly adapted to the whiplash test at speeds of up to 16km/h. Thus, it can be seen that there is a gap in the use of crash test dummies. There are no low-speed dummies for side and front crash tests, and there are no dummies for rear crash tests between 16 km/h and 25 km/h. Which corresponds to a collision of a passenger vehicle with a hard obstacle at a speed of 30 km/h. Therefore, in collisions with low speeds of 20 km/h, the splash airbag will probably not be activated. The article contains the results of a computer simulation at a speed of 20 km/h vehicle out in the ADAMS program. These results were compared with the experimental results of the laboratory crash test using volunteers and the Hybrid III dummy. The simulation results are the basis for building the physical model dummy. The simulation aims to reflect the greatest possible compliance of the movements of individual parts of the human body during a collision at low speed.

Kinematics of the motorcar body side deformation process during front-to-side vehicle collision and the emergence of a hazard to car occupants

The kinematics of the process of deformation of the motorcar body side in the culminating phase of a front-to-side vehicle collision has been examined as a possible basis for analyzing and modeling the process of emergence of a hazard to car occupants during a road accident. The course of such accidents has a complex nature and their models are necessarily based on the approximation of non-linear elastoplastic characteristics of impact processes, especially during the transition from the compression phase to the restitution phase of the deformation process. For such characteristics to be obtained, a lot of experimental tests have to be carried out. This paper addresses the short-duration processes with a high degree of complexity.A front-to-side motorcar collision model has been prepared, which made it possible to analyze the process of deformation of the car body side and the emergence of a hazard and injuries to car occupants. The results of calculation of the deformation rate and range in various car body zones, velocity of the test dummy placed on driver’s seat and velocity of possible dummy’s impact against the car body side being deformed may be taken as a basis for designing effective occupant protection systems. The kinematics of the phase of vehicle contact and deformation process was modeled with taking into account results of experimental tests, including the curves characterizing the largely non-linear processes that are decisive for the deformation of the car body side. The deformation processes analyzed on these grounds showed at the same time the range of penetration of the deformed body part into the car interior, which causes a hazard to vehicle occupants. The calculation results have shown e.g. that the car body side is deformed to a depth of 0.2 m as quickly as within 0.02–0.03 s. At such a car body side deformation range, the car body part being deformed hits occupant’s body in his/her hips and pelvis area with a velocity of about 6 m/s.

Оценка сложности сборки узлов электронной аппаратуры

The article is devoted to the complexity assessment of harvesting systems. The author considers peculiarities of assembly lines as production systems and the reasons for the constant growth of their complexity. Complex assembly systems are expensive to implement, run, control and maintain, while their complexity affects performance, quality and reliability. Thus, when designing any assembly system, one must look for compromises between its future operation features, its cost and its complexity. To do this, you need to be able to quantify the complexity. This study made it possible to classify the methods of complexity analysis and propose a model that allows quantifying, to some extent, the complexity of the assembly of electronic units and can be used to work with complex multi-subject lines. The study considers the complexity indicators for the operator`s work. To numerically assess the complexity indicators, it is proposed to use the Likert scale. It is assumed that further research should take into account the following issues. The assembly should be designed with consideration of the human factor and the interrelation of technological operations, tools and ergonomics. This is due to the fact that in manual and semi-automatic workplaces, the human operator plays the crucial part. The connection between ergonomics and complexity must be established using the utility function, methods of fuzzy logic, and computer experiments with a test dummy.

Lower Limb Design for a Child Test Dummy, based on Osteogenesis Imperfecta characteristics

Active and passive safety have played an essential role in solidifying ground transportation. However, safety-focused on children with some rare diseases is little attacked. This article shows the design of a diseased leg prototype into a crash test dummy Q3, the novelty of this work is based on the morphology and biocompatibility of the lower limbs, which principal characteristics of this prototype replicate the shape of a child with bone-degenerative diseases. In this work, it shows the essential features that a child dummy of this type must contain in order to generate a homologation and approval under the strictest passive safety standards used in the automotive industry. Results show the important kinematics parameters and CAD bones development necessary to conform a new numerical crash test dummy prototype.

Accidental Injuries Caused by Automotive Frontal Collision

ABSTRACT This study aimed to use a simulated vehicle to asses quantitatively the head and neck injuries of the occupants, in a frontal car crash, when the driver has only one hand on the steering wheel, such as while using a cell phone when driving. First, we conducted a survey of NHTSA reports on real laboratory tests of frontal collisions involving sedans. The effects of these collisions on the neck of a Hybrid III 50th percentile male crash test dummy were measured in terms of average head acceleration and force along the X, Z, and Y-axes. These acceleration, force and torque values obtained from the NHTSA database were used to validate the simulated model. The results obtained were compared with case E, the standard dummy position used in frontal collision tests. The results obtained in the simulation of the four cases of driving with only one hand demonstrate a probability of more than 67% that the driver will sustain AIS+2 injuries during a frontal crash. In all the cases, the skull fracture percentage was the most representative, occurring between 89 and 94% of cases where the driver had only one hand on the steering wheel.

Malaysian Vehicle Seat Anthropometry Studies: A Mini-Review

This paper focuses on anthropometry studies in Malaysia within a 10 years’ span. In the beginning, Malaysian anthropometry study has only been the interest of researchers from the medical field. However, in the past 10 years, other fields like the engineering and social studies began to explore aspects of anthropometry. Driver’s seat has been the central of ergonomic evaluation and analysis for automotive engineering. The data established for Malaysian driver’s seat includes the seat fit parameters, seat postural angles and seat pressure distributions. There were also studies that revealed that the collected data showed significant mismatches between the subjects and the anthropomorphic test device or better known as crash test dummies. Even though currently there are satisfactory data for Malaysian population, these data have to be reviewed subsequently as shown in many nations because there is usually some progress in growth.

Design and Evaluation of a Pediatric Lower-Limb Exoskeleton Joint Actuator

Lower-limb exoskeletons have undergone significant developments for aiding in the ambulation of adults with gait impairment. However, advancements in exoskeletons for the pediatric population have comparatively been lacking. This paper presents a newly developed joint actuator designed to drive the hip and knee joints of a pediatric lower-limb exoskeleton. The performance requirements associated with the actuators were determined based on a target audience of children ages 6–11 years old. The developed actuators incorporate a hybrid belt-chain transmission driven by a frameless brushless DC motor. One actuator underwent benchtop testing to evaluate its performance with respect to their torque production, bandwidth properties, backdrivability in terms of inertia and friction characteristics, speed capabilities, and operational noise levels. As a preliminary validation, a set of actuators were placed in a prototype orthosis to move a pediatric test dummy in gait tracking via state-feedback control. The results showed that the newly developed actuators meet the design specifications and are suitable for use in the pediatric exoskeleton being developed.

Designing and testing a stand used to simulate the dummy head impact with different surfaces using CAD software

The aim of the paper was to design, assemble and test a stand used to analyse various crash scenarios for a crash test dummy head. This stand can be used to test the head impact with different surfaces, with or without a helmet, on soft or hard surfaces at different impact angles. The idea was to design the stand in the CAD software SolidWorks because this particular software has the feature of dynamic simulation of assemblies known as Motion Analysis. The results show that designing the stand was a success and the simulations show a good behaviour of the assembly with direct results generated in term of acceleration and force values obtained from the drop test of the head on a surface. Also, the surface can be adjusted for different impact angles and with different contact surfaces properties to extend the usability of the assembly.