On the simulation of electric scooter crash-test with the hybrid human body model

This paper introduces the reader to the problem of traffic accident reconstruction from a technical perspective solution and simulation tools. The observed accident is not a real accident, but an experimental crash test of a BMW E87, ${118}\mathbf{i}$, and an electric scooter. The rider of the electric scooter in this experiment was replaced by a dummy Primus, representing the average EuroNCAP male (175 cm, 78 kg). The dummy was placed on top of the electric scooter and positioned in front of the vehicle so that it was knocked from the left, approximately in the middle of the vehicle. The vehicle was accelerated to a speed of approximately 50 km/h and at this speed struck the rider of the electric scooter, who was gradually struck on the bonnet and windscreen of the vehicle, the scooter being thrown forward. The output data from the experiment and the input data for the reconstruction (simulation) are the initial and end positions of the dummy, scooter, and vehicle, vehicle deformation, and damage/injury to the dummy. The simulation tool used is finite element method software Virtual Performance Solution, in which the vehicle and scooter model was created and a hybrid human body model: Virthuman was used. The vehicle was modeled as partly rigid and partly deformable (deformable in the frontal part, where contact with the driver appears) and rigid in the rest, in order to speed up the computation time. The scooter was modeled as rigid in its entirety (to speed up the calculation and irrelevance of the deformation data - they do not affect the rider dynamics and these data are not available). The Virthuman model is a numerical human body model, which could represent an individual of a given height, weight, age, and sex. This model is suitable specifically for simulations of dynamic phenomena with potential impact. The main idea of this study was to develop a kind of methodology for accident reconstruction of scooters and electric scooters and to identify the relevant data needed for the simulation tools. The principle is to vary unknown input data (rider position relative to the vehicle, vehicle speed, etc.), and monitor the simulation results. The aim is to keep the known input data and variations of those of the unknown, simulation results as close as possible to the results of the experiment (vehicle damage, injury and final position of the rider, etc.). In this way, it is possible to determine the possible initial state and progress of the accident and thus obtain information (data) that could not be obtained at the accident scene and which may help to clarify or exclude a given collision scenario, or could be used for the development of future safety systems.