Crash test dummy
Crash test dummies ( Anthropomorphic Test Devices [ ˌæntθɹəpəʊˈmɔːfɪk tɛst dɪˈvaɪsɪz ], ATD s for short ) are life-size dummies that are used to simulate the effects of traffic accidents on the human body . Dummy [ ˈdʌmɪ ] comes from English and stands for dummy .
The dummies are equipped with numerous sensors that measure the loads during a crash test . Their biomechanical properties must ideally match those of the human body - for example the dimensions and masses of the individual body parts and the stiffness of the various joints - so that they simulate reality as well as possible. There are dummies that simulate male or female bodies, as well as designs for different body sizes and ages. The calibration of the dummies is primarily done by comparing them with data from corpse experiments . Crash test dummies have recently become indispensable for the development of almost all vehicles and are required in some cases in order to obtain approval for a new vehicle model .
Accident research prior to the development of crash test dummies
The need for accident research
On August 31, 1869, it is believed that the Irish scientist Mary Ward became the first victim in a car accident. She was driving a steam powered vehicle with her husband in Parsonstown, Ireland and was thrown out, resulting in being run over. Henry Bliss made history after becoming the first car accident victim in North America on September 13, 1899 , when he was hit while exiting a streetcar in New York City . It is estimated that over 20 million people have died in car accidents worldwide since the early days of automobiles .
The need for accident research for the automotive industry arose very soon after commercial automobile production began in the late 1890s. As early as the 1930s, the automobile became a normal part of public life. With the increase in the volume of traffic in vehicles whose developers cared little about the safety of other road users, death rates on public roads became a serious matter. The death rate had reached a value of 15.6 deaths per 100 million automobile miles - it was still to be assumed from a steady increase together with the traffic density (for comparison: today's figure is around 1.8 deaths per 100 million despite the much higher traffic density Car miles).
In the 1930s, the passenger compartment was not sufficiently safe even in low-speed traffic accidents. The dashboards were made of hard metal , the steering wheel was rigid and bolted tight, and protruding buttons, inflexible levers and linkages were fatal in the event of a collision. There were no seat belts , which is why the occupants were thrown through the windshield even at low frontal impact speeds where often only a small chance of survival existed. Before the introduction of all-steel bodies , the superstructures were made of an unstable sheet metal-clad wooden frame and folded up in the event of an impact, so that the impact forces acted directly and almost uninhibited on the occupants. Until the late 1950s, there were statements from vehicle manufacturers that car accidents “simply cannot be survived” . The forces in a traffic accident are too great even at low speeds and the human body is too vulnerable.
Some vehicle developers, however, took this deficiency as an opportunity to start research into the product safety of their automobiles. Automobile accident research was born, and the first tests were soon carried out on volunteers.
Research on corpses
The Wayne State University in Detroit was the first place where the scientific data collection began on the effects of car accidents on the human body. In the late 1930s there was no scientific study of the behavior of human bodies under heavy physical stress, or any scientific method to determine it. The science of biomechanics was almost untouched. It was therefore necessary in the burgeoning accident research to generate new data.
The first test objects were human corpses, which were used in corpse experiments to measure the basic resistance of the human body to crushing and pulling forces, as are the rule in automobile accidents. To measure these parameters, steel weights were dropped on body parts and bones, as well as entire bodies in unused elevator shafts. In each case, the acceleration of the falling objects could be determined most easily through the free fall . A further step was that corpses - provided with accelerometers - were tied up in automobiles, and these experimental set-ups were used in frontal collisions and rollover.
In Albert King's 1995 article Journal of Trauma , the Humanitarian Benefits of Cadaver Research on Injury Prevention section shows the declining number of deaths in automobile accidents and thus the value of cadaver research in protecting human life. The calculations show that as a result of the automobile design changes, up to 1987, thanks to corpse research, around 8500 lives were saved every year. He notes that for every corpse used for research purposes, 61 people survived annually because they were wearing a seat belt. 147 people survived because they were rescued by airbags and 68 survived because the windshields were adjusted.
However, research on cadavers posed numerous problems and inaccuracies. At first there were fundamental research obstacles because the corpses used were not representative of the demographic average of the accident victims, since the selected, exclusively non-violently deceased, were almost exclusively older adults. There were also moral and ethical concerns as to whether such research should even be carried out on the dead. There were also only a few experiments on the corpses of children, as these were rarely made available to researchers. Corpses from accidents could usually not be used, as they would not have allowed an error-free simulation due to the existing injuries and would have compromised the test results. Since the corpses were physically different and could hardly be compared without errors, and a test object could not be used several times, there were great difficulties in creating reliable data sets. For these reasons, the researchers were at times short of test subjects, and the biometric data of their results were almost limited to older, white men.
At the Graz University of Technology , slingshot tests were carried out with corpses as part of an EU project.
Accident research on volunteers
Some researchers made themselves available as volunteer test subjects. Colonel John Paul Stapp ( USAF ), for example, allowed himself to be accelerated to up to 1000 km / h in several attempts on a rocket sled , and then slowed down in less than a second. Lawrence Patrick , a professor emeritus from Wayne State University (Detroit), made more than 400 experiments on a rocket sled to investigate the effects of negative acceleration (deceleration, deceleration) on the human body. He and his students allowed heavy steel weights to be dropped on their chests and face to simulate impacts on impact during a traffic accident. They were also blown against shattered glass in order to simulate the effects of a windshield breakage while driving or on impact.
While he admitted that he "slight pain" (Engl .: "a little sore" ), had told Patrick that the research of his team will be a pioneer in the development of mathematical models that can be measured in terms of future research.
Although data from volunteer tests were available, tests on humans were not conducted beyond the limits of a certain level of physical exertion (e.g. pain). Other test objects were still required to collect information about the effects of heavier loads and the success of possible protective devices.
Animal testing
By the mid-1950s, many options for researching corpses had already been exhausted. However, there was still a need for research into the survivability of accidents in areas where the bodies were poor test subjects. Since corpses were still poorly available as test objects, the researchers were forced to get other test objects: Animals were now also acquired for accident research ( animal experiments ). A report by Mary Roach of the Eighth Stapp Car Crash and Field Demonstration Conference (in German about: Eighth Stapp Autounfall- and field demonstration Conference ) According to experiments occurred chimpanzees on Rocket Sled, a bear in a collision with a swing and stunned pig in a sitting position in front of the steering wheel (quote: "We saw chimpanzees riding rocket sleds, a bear on an impact swing… We observed a pig, anesthetized and placed in a sitting position on the swing in the harness, crashed into a deep- dish steering wheel at about 10 mph. " ).
Important research, which could not be carried out on bodies or volunteers, was that of reducing injuries caused by impact with the steering wheel. By 1964, according to some sources, over a million people died in traffic accidents of this type. General Motors' introduction of the steering wheel, which collapses and yields on impact, in the early 1960s reduced the death rate from steering wheels by fifty percent. The most common test objects for collisions in the interior of vehicles were pigs (Project Barbecue) because their body structure in the lower chest area is halfway similar to that of humans, they could stay in the vehicle in a fairly close sitting position and their ribs break under almost the same stress as humans. The ability to sit upright was an important requirement for animal studies in general. Research continued on animals into head injuries to human victims from the dashboard and switches and rearview mirrors .
In 1980 reporters for the magazine stern documented the stresses and strains the animals were exposed to in an institute in Bron , France , where baboons, dogs, and above all pigs were used. The latter were used thousands of times a year in artificially simulated accidents on behalf of the European auto industry. The scientific director of the tests in Bron, which was funded by the Federal Highway Research Institute , justified the high level of animal wear and tear with the fact that every accident proceeds differently and every change to the body, seat belts or headrests requires long series of tests in order to statistically record the respective load capacity. He considered dead bodies unsuitable because of the lack of muscle tension. While the pigs were being sedated before the crash, the monkeys and dogs with brain electrodes were often not anesthetized because the researchers wanted to obtain as much unadulterated data as possible, including sensations. Baboons were used several times in Bron for cost reasons, so the zookeepers often had to use brutal force to clamp them onto the sled: “Some monkeys get so crazy after a few attempts that we can only use them for the really big bang, after which they guaranteed are gone. "
The writer Hans Ruesch and the magazine Quick reported on experiments from 1965 in which pathologists at the Medical Faculty of Tulane University had thrown 200 rhesus monkeys on impact sleds against a wall to study the effects of traffic accidents. Such - publicly funded - attempts increased rapidly in the mid-1960s, especially in the USA. The Tulane experiments, for example, were repeated at the University of Oklahoma with pregnant baboons.
While experiments on corpses have already provoked some resistance in the population, for example through religious institutions, there was a certain acceptance, since human lives could be saved through these painless test objects. Animal research, on the other hand, provoked much more violent resistance from animal rights groups , who vehemently protested against research on pain-sensitive living beings. In Michigan, for example, in February 1978, baboon crash tests were stopped by protests. While some researchers supported animal testing because it provided reliable, if not entirely adequate, data, there were serious ethical concerns about these processes.
According to information, animal experiments are no longer carried out by any of the larger automobile manufacturers. General Motors, for example, ended the live tests in 1993, and numerous other manufacturers did so in the same period.
The story of the first dummies
The first crash test dummy, named Sierra Sam , was built in 1949 by Sierra Engineering Co. for the US Air Force and was used to test ejector seats and belts . These tests were carried out at speeds of up to 1000 km / h on rocket sleds or by dropping the dummies from a crane. With his height of 1.85 m he corresponded to the "95 percent man", mathematically the 95 percentile , which means that he was taller and heavier than 95% of all male adults.
In the early 1950s, Alderson and Grumman designed a dummy that would be used for both automotive and aircraft crash research. Alderson later produced the VIP 50 series for General Motors and Ford , which was taken over by the National Bureau of Standards . Sierra followed with a dummy in competition, the Sierra Stan model , but General Motors found that neither model series met the requirements. GM technicians developed the Hybrid I model , which was supposed to combine the positive properties of the other two models and had the average height, weight and measurements of the male population, which is why he was called the "50 percent man". Working with the Society of Automotive Engineers (SAE) , General Motors shared this design with its competitors.
Since then, a lot of work and research has been put into the further scientific development of the dummies. The Hybrid II model was developed in 1972 and had improved shoulder, spine and knee mechanics; it was unveiled in 1973. These first two really human-like dummies Hybrid I / II had accelerometers in the head, chest and pelvis and an additional measuring device to determine the forces in the thigh.
The National Highway Traffic Safety Administration (NHTSA) contacted General Motors with a request for a model with numerous, finer features that needed improvements over Hybrid II. Despite great advances in the various research areas, Hybrid I and Hybrid II were still rather crude models and could not be used for all tests. Work has now been carried out on a new dummy - the Hybrid III - which should meet the requirements and is still in use today.
Current model series of crash test dummies
The Hybrid III family
The Hybrid III, the "50 percent man", which was presented by General Motors in 1976, is the most popular crash test dummy and now has a "family" as it comes in many different versions with different sizes and weights .
The most frequently used HIII 50% Middle Adult Male ( "middle" for medium , "adult" for fully grown and "male" for male ) would measure 175 cm in height and weigh 78 kg if he could stand upright. It corresponds to the average male car driver assumed by the manufacturer. His "big brother", the HIII 95% Large Adult Male (English "large" for large ), would be 188 cm tall and weigh 101 kg. It is thus greater than 95% of the male car drivers assumed by the manufacturer. The female specimen HIII 5% Small Adult Female ( “small” for small , “female” for female ) would measure 152 cm upright and weigh 54 kg. It is thus greater than the lower 5% of the female drivers assumed by the manufacturer.
There are three Hybrid III child dummies, representing children weighing 16.2 kg (for three years), 23.4 kg (for six years) and 35.2 kg (for ten years). These three models have only been added to the range after the adult models.
Modern hybrid III dummies can be equipped with a large number of sensors in the head, neck, chest, spine, pelvis and legs. The most common uses are accelerometers and force sensors . However, protractors for the knees and angular speedometers for the head are also used.
Other models
In addition to the widespread dummies of the Hybrid model series , which were developed for front-end impact tests, there are a number of other dummies:
For example, models that are used to investigate accidents with side impacts, the SID (for side impact dummies (English), in German side impact dummies): Among them the EuroSID - 1/2 ( European Side Impact Dummy 1/2 ; European side impact -Dummy) and the US-SID (American SID), which correspond to the standard for Europe and the United States, respectively.
The BioRID II ( Biofidelic Rear Impact Dummy II = rear impact dummy biologically modeled on humans) helps to develop safer headrests and seats in experiments with rear impacts.
CRABI is a dummy that helps to investigate the use of child seats and is available as a representative for the age groups six months, twelve months and 18 months old.
THOR is a newer "50 percent man" and successor to the Hybrid III . THOR has an improved spine and an improved pelvis, and the face contains some previously unused sensors for investigating possible facial injuries. THOR is equipped with a larger number of sensors, which also have a higher sensitivity and thus accuracy than the Hybrid III.
The biofidelic dummy (also called BD dummy) is an anthropomorphic test body originally developed in the engineering office Priester und Weyde through student work, which is used as a surrogate for pedestrians and cyclists for full-scale crash tests. This dummy is not only capable of generating realistic damage images on vehicles, but also corresponds as closely as possible with the human model in terms of biofidelity, in order not only to obtain human-like movement behavior during a crash test, but also to draw conclusions from the damage to the dummy about the probability of injury to be able to pull. It is being further developed in cooperation with the Dresden University of Applied Sciences. The production and distribution are carried out by the Crashtest-Service company in Münster.
The testing process
Every Hybrid III is calibrated before a crash test. His head is removed and dropped into an apparatus from a height of 40 cm to tune the instruments inside.
Then the head is screwed onto the shoulder area and the flexibility of the neck is checked after a short acceleration and sudden braking. Finally, the shoulder area and head are connected to the torso, which was struck by a pendulum in a test apparatus in order to check the flexibility of the chest.
After the readiness of the dummy has been checked, it is dressed in yellow and provided with liquid paint on the head and knees. The dummy is placed in a test device (e.g. sled) or a complete test vehicle. During the impact it records over 30 different data with its built-in instruments, marks the points of impact with the color and is filmed by high-speed cameras. The data is transferred from the sensors to a measuring system inside the vehicle using cables (analog technology). There are digital versions of dummies in which the data is stored in a miniature data system in the dummy (in-dummy measuring system) and is read out from the system and processed further after the test. The data is recorded on memory in the dummy 's chest. A dummy used for motorcycles is based entirely on digital technology and data acquisition.
Since the hybrid is a standardized test object, the parts can be interchanged and replaced individually in the event of a defect. Of course, the devices are designed for multiple use. A fully equipped dummy is worth around 150,000 euros.
The future of crash test dummies
In accident research, crash test dummies have contributed to the creation of data sets on the consequences of traffic accidents for the human body. Numerous hazardous parameters, such as the vehicle design, have been improved.
Meanwhile, the yield of new data for research has become quite low. Since the problem of the reproducibility of an experiment compared to the cadaver and animal experiments has been resolved, the problem still exists that the test vehicles used do not always show identical behavior (i.e. have a series spread) and can only be used once.
Another problem is that dummies only approximate a human being. For example, the investigation of the effects on internal organs is rough at best and can be carried out better through cadaveric experiments, but not satisfactorily.
The future of crash tests can be seen in computer models. However, today's computer capacities are not sufficient and the models are not yet accurate enough to carry out computer simulations of entire body systems in such situations. It is a big problem to reliably model all relevant boundary conditions, both of the car with its rigidity and of the human body. The advantage of computer simulations, however, is that they offer reproducibility of experiments. Since influencing parameters can be varied in a controlled manner, computer simulations can reduce the need for physical tests to a minimum.
For the legal certification of new vehicle models, it is currently mandatory to examine the properties in physical crash tests - with crash test dummies. But it can be assumed that the future of the dummy will take place on the computer screen.
Crash test dummies in the cultural landscape
The human-like appearance of the crash test dummies has led to the frequent anthropomorphic use of the dummies in the cultural landscape since its development.
In the 1980s, which brought US Department of Transportation ( American Department of Transportation) a commercial on his own behalf in American magazines and in local TV out, speaking in the two crash test dummies named Vince and Larry on slapstick -Art about safety matters in vehicles (for Example seat belts) spoke. The campaign with the English slogan "You can Learn a Lot from a Dummy" (German for "You can learn a lot from a dummy" ) was so popular that the two figures since then regularly in safety campaigns - preferably for children - up.
In the early 1990s, Tyco Toys developed a series of action figures called The Incredible Crash Dummies (English, in German: "The incredible crash test dummies" ) based on the commercials. The colorful toys fell apart when a button on her stomach was pressed and could then be reassembled. There were also vehicles that could also be reassembled by the child after the “crash test”.
The popularity of the toys resulted in a 22-minute television program of the same title, which was produced entirely with 3D computer animation film technology in a way that was unique for the time . In addition, it was a comic book series and a Nintendo - video game (for NES ) and one for the Nintendo "Game Boy".
In the cut versions of the racing game series FlatOut , crash test dummies are used instead of human drivers.
In the late 1980s, a Canadian rock band called themselves Crash Test Dummies .
The firm Denton ATD is the most famous manufacturer of crash test dummies for the automotive industry in the United States and has several offices in other countries, including Germany. This company also produces models from the Hybrid III dummy family.
Other dummies
- Paradummy - a dummy parachutist used by the military
- Kiel doll - a two-dimensional template of body geometry
- Resusci-Anne - a training dummy for cardiopulmonary resuscitation
- Ballast Dummy - Rough body image for exercise tests with body weight
Individual evidence
- ^ Offaly Historical & Archaeological Society in Famous Offaly People ( Memento January 5, 2006 in the Internet Archive ) on Mary Ward (1827–1869)
- ^ Gary Carden: A curious look at the lives of the dead ( Memento from January 20, 2005 in the Internet Archive )
- ↑ Crash tests with corpses at TU Graz derstandard.at; Crash test corpses orf.at, accessed on January 23, 2015
- ↑ Nick T. Spark; Ejection Site: Fastest Man on Earth ; Wings / Airpower Magazine
- ↑ John L. Frisbee; "Valor: The Track to Survival" ( Memento from February 10, 2006 in the Internet Archive ), May 1983, (Vol. 66, No. 5)
- ↑ a b Mary Roach; I was a human crash test dummy
- ↑ a b c Nikolaus Eckardt, Hans Pérukel: Attention, ready ... off! In: stern. No. 6. January 31, 1980, pp. 16-22.
- ↑ Hans Ruesch: Naked ruler. The undressing of medical science. Edition Hirthammer Tier- und Naturschutz-GmbH, Munich 1978, ISBN 3-921288-44-4 , pp. 300-301.
- ↑ Little monkey, get ready to die! In: Quick. December 26, 1965.
- ↑ Hans Ruesch: The forgers of science. Technical report. 4th edition. Hirthammer Verlag GmbH, Munich 1990, ISBN 3-921288-53-3 , pp. 90-91.
- ^ Guardian. February 8, 1973. Quoted in Richard Ryder: Victims of Science. 2nd Edition. London 1983, p. 151.
- ↑ Peter Singer: Henry Spira and the animal rights movement. Harald Fischer Verlag GmbH, Erlangen 1998, ISBN 3-89131-404-3 , p. 98.
- ↑ How the Test are done Crash test information page on the car manufacturer Citroën
Web links
- How the dead have helped the living , on corpse experiments for accident research
- Information about Sierra Sam (English)
- Article about female crash test dummies (English)
- Report on Professor Lawrence M. Patrick who carried out self-experiments on accident research
