![]() ![]() ‘The model already included those options’, says van Zandwijk. The researchers can also assign the virtual dummy the same sex, weight, and height as the ‘victim’. The researchers then entered the same starting position and forces into the computer model to see if the virtual dummy would move in the same way as the test subjects, examining the behaviour exhibited during a fall as well as what that type of fall looks like. ![]() ‘We also measured the pushing force using an instrument that I designed especially for that purpose, to gain as much knowledge as possible about the force impacting the test subjects.’ How do all the joints move in relation to each other? What force does the body exert on the ground? To allow for these measurements, test subjects wore a special suit during their fall or jump containing sensors that recorded their movements’, says Hutchinson. ‘We then began measuring the test subjects in as much detail as possible. Naturally, the test subjects had a soft landing, ending up in a large pit filled with foam blocks with a trampoline as the undersurface. The fall tests involved subjects jumping, falling or being pushed from a height of 2.5 metres. In order to gain a better understanding of the falling behaviour of real people and to be able to compare it with the way the model falls, the researchers conducted fall tests with test subjects. The researchers can use the model to simulate a fall, but can equally simulate a movement resulting in someone having been pushed, for example. The dummy can be placed in a variety of starting positions and a fall can then be simulated to determine where the dummy ends up. The model calculates how the human dummy were to fall if you were to place it in a certain position and were to push it with a certain amount of force, based on the laws of physics.’ ‘Only our model is a virtual dummy – a human dummy inside a computer. ‘You might compare it to a “crash test dummy”, which is a dummy that they use to simulate car accidents’, Hutchinson explains. Van Zandwijk and Kim Hutchinson, a BioMechanical Engineering student at TU Delft, have been testing this model over the past two years with the aim of examining whether the model could be used for forensic investigation. The researchers arrived at an existing commercial computer model that was developed for the automotive industry. That is why the NFI launched the Icarus project two years ago. ‘However, occasionally what you may see at first glance will differ from what actually happened,’ says Jan Peter van Zandwijk, a forensic scientist and the project leader, ‘ which is why a computer model could assist the investigation.’ ![]() For example, if the person is lying in a conspicuous position, investigators at the scene will attempt to identify what may have happened and whether the traces match a particular scenario. their position, will often already give the police an idea of what may have happened. Test falls with subjects and foam block pit Drop tests with test subjects in a container with foam blocks ![]()
0 Comments
Leave a Reply. |