Ride Comfort Transfer Function for the MAGLEV Vehicle Transrapid

Abstract

In order to predict the ride comfort for the MAGLEV vehicle Transrapid TR09 for various scenarios, e.g. for higher vehicle speeds than hitherto travelled, a transfer function from the excitations given by the guideway position to the relevant car body acceleration is calculated by two different methods. Method A is based on a mechatronic simulation model of the Transrapid TR09 which describes a two- dimensional lateral cross section of the vehicle. The simulation model consists of a 2D multibody system describing the mechanical part, four network models of the electro-magnets - two levitation magnets and two guidance magnets - and a signal model of each magnet controller. These signal models contain a representation of the authentic C-Code of the control law used within the actual magnet control units within the vehicle TR09. The overall model can be exploited to calculate the accelerations of the car body for given excitations at the interfaces between guideway and vehicle. Moreover, it is possible to generate a model-based transfer function in the frequency domain from the guideway excitations to the car body accelerations. For method B, measurement results of test runs of the Transrapid TR09 at the test track TVE in Northern Germany are exploited which were recorded for vehicle dynamics analysis and ride comfort evaluation in 2009. From these measurement results two characteristic quantities are generated for several different velocities of the vehicle: Firstly, the position of the guideway is reconstructed by using an integration of the absolute accelerations of the magnets and the signals of the magnet's sensors for the air gap. Secondly, the relation between the accelerations at the car body of the vehicle and the guideway position is calculated as a transfer function in the frequency domain. For this, the measurement data and the reconstructed guideway position are both transformed into the frequency domain by a Fast Fourier Transformation (FFT). The resulting transfer function gives the relevant accelerations for the ride comfort for given excitations of the vehicle as calculated by Method A above. The two transfer functions from Method A and B are compared for validation. Then, a smoothed version of the validated transfer function is applied for estimating the ride comfort for travelling scenarios which have not yet been measured in practical operation, e.g. for higher velocities of the vehicle.