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Precrash vehicle velocity determination using inverse system and tensor product of Legendre polynomials - subcompact car class

Gosławski Łukasz, Madziara Szymon, Droś Bartosz, Knap Lech, Ma Yanlin, Mrowicki Adam

Archiwum Motoryzacji

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2022

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Vol. 97, nr 3

14--24

EN

Presented paper discusses new approach to EES parameter determination in frontal car crash based on the tensor product of Legendre polynomials. In this paper Subcompact Car Class was analyzed using that method. Data that was used to perform analyses introduced in this paper was taken from National Highway Traffic Safety Administration (NHTSA) database. Such database consists of considerate number of test cases along with various information including vehicle mass, crash velocity, chassis deformation etc. New approach to the problem of determining the EES parameter was necessary due to the low accuracy of the currently used methods. Linear models used up till now for accident reconstruction show significant error as the relationship between mass, velocity and deformation cannot be well approximated with a flat plane. Proposed model produces better results, because of the nonlinear dependence of said parameters. This paper also includes a calculation example presenting a comparison of linear and nonlinear method on an actual crash test.

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Nonlinear method of precrash vehicle velocity determination based on tensor product of Legendre polynomials - luxury class

Gosławski Łukasz, Sys Ewa, Mrowicki Adam, Krukowski Mateusz, Ma Yanlin, Kubiak Przemyslaw

Archiwum Motoryzacji

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2022

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Vol. 95, nr 1

53--64

EN

Presented paper discusses a new, nonlinear approach to EES (Equivalent Energy Speed) parameter determination in frontal car collisions. This method is based on tensor product of Legendre polynomials and in this case considers Luxury car class. Methods that are used up till now are based on a linear dependency between mass, velocity and deformation. This is of course a simplification that was necessary, due to limitation in computation power of computers when this method was introduced decades ago. The contemporary resources allowed Authors to develop a much more sophisticated method. The mathematical model was developed using data shared by National Highway Traffic Safety Administration (NHTSA). This database covers a large number of test cases along with various information including vehicle mass, crash velocity, chassis deformation etc. New method proves to be more accurate than the currently used approach utilizing linear dependency of deformation force and deformation of the vehicle.

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Analysis of braking marks left by vehicles equipped with ABS with IR spectroscopy – different types of asphalt

Sys Ewa, Kubiak Przemysław, Gosławski Łukasz, Zakrzewicz Wojciech

Archiwum Motoryzacji

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2021

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Vol. 93, nr 3

5--14

EN

Detailed analysis of literature showed that there is no method that can be used in order to investigate skid marks left by vehicles equipped with ABS. Authors decided to identify braking trace by using IR spectroscopy. Preliminary studies have been performed and results were promising. Due to that fact authors decided to conduct detailed research where the influence of various factors on the possibility of revealing breaking traces would be taken into account. This article is the first in a series of articles taking into account the influence of various factors on the possibility of revealing breaking marks using IR spectroscopy. In this article the influence of the type of asphalt was studied. Authors conducted tests with the most popular types of asphalts used for the wearing course. 100 samples from 5 different types of asphalt were prepared. Each sample was measured 3 times to create its spectrum. The results were analyzed thoroughly using the dedicated SpectraGryph software. The analysis showed that for 4 out of 5 types of tested asphalt, the braking traces were visible at a wavelength of approximately 11 500 nm. Only for the rubberized asphalt there weren’t possibility to reveal skid mark.