EVU XXVI 2017 – 17 Generating and validating multibody simulation models of e-bikes for PC-Crash  

Generating and validating multibody simulation models of e-bikes for PC-Crash
Martin Urban1*, Felix Dauer2, Dr.-Ing. Christian Erbsmehl1
1Fraunhofer Institute for Transportation and Infrastructure Systems IVI , 2Robert Bosch GmbH Automotive Electronics,
System Architecture and Simulation
*Corresponding author e-mail: martin.urban@ivi.fraunhofer.de

Abstract

The PC-Crash software for reconstructing traffic accidents by the company DSD offers the opportunity to
use multibody models to simulate a realistic behavior of accident participants. Not only predefined
multibody models are available. Furthermore, it is possible to define own models. Due to the fact that no
given model for simulating an electric driven bike (E-bike) had existed, the task was to define a new
multibody model for E-bikes. A predefined bike model with rider serves as basis for the new model. It
was completed by additional elements to an E-bike. Based on real crash tests, the multibody model for Ebikes needs to be confirmed. The aim was to obtain an adequate accordance for both, the acceleration on the upper front fork and on the seat post between crash tests and simulations. To validate the multibody models (Shape), the Robert Bosch GmbH executed crash tests for different E-bike models. For this E-bike models, different Shapes for PC-Crash were generated by the Fraunhofer IVI. The fundament of all Shapes was a predefined bike model by DSD, which had been completed with the special electric elements (e.g. storage battery, electric engine). The Shapes were defined in length, width, height and weight, depending to the real E-bike. In order to adapt the E-bike behavior in simulation to the crash test behavior, the changing of the properties of bodies and joining elements of the Shape was required.

Within the simulation, the properties stiffness and hysteresis of the bodies, the friction and stiffness of
the joints elements and the stiffness and damping of the spring-dampers elements got modified. The
Robert Bosch GmbH carried out crash tests for the three E-bikes ‘mountain bike’, ‘woman bike’ and ‘man bike’ for thirteen different scenarios. Three different Shapes for PC-Crash had been generated for the three bikes from Fraunhofer IVI. For each Shape, more than twenty properties of the multibody model were varied to attend a high accordance of acceleration between the crash tests and the simulations. The new multibody models are a well-balanced models to simulate different crash test scenarios with one Shape for each E-bike. Reconstructing any traffic accident of E-bikes with validate multibody models became possible on the basis of this three Shapes. The shown method emphasizes that it is possible to validate multibody models also for other vehicles like E-bikes with a manageable effort.

La lettura di questo articolo è riservata ai soli Soci EVU Italia

Autore	Martin Urban1*, Felix Dauer2, Dr.-Ing. Christian Erbsmehl1 1Fraunhofer Institute for Transportation and Infrastructure Systems IVI , 2Robert Bosch GmbH Automotive Electronics, System Architecture and Simulation
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