Simulation-based identification of excitation spectra for a dynamic suspension test rig

The objective characterization of modern vehicles on roads and test rigs regarding ride comfort delivers a key factor for an efficient vehicle development process. To completely understand the vibration phenomena of a vehicle, detailed information about the subsystem suspension in the relevant frequency range is required. This study presents a method to derive excitation spectra for a dynamic suspension test rig from full vehicle measurements or simulations while passing uneven roads. Hence a method to generate synthetic single-track excitation signals has been developed to simplify the treatment of excitation signals on the test rig as well as in the post processing. Furthermore the presented method has been extended to provide synthetic double-track excitation based on a modal decomposition into heave and roll excitation signals. Additionally, this methodology allows to integrate several vehicle setups, suspension types and ride speeds into the synthesis process to receive a synthetic excitation that is independent from the vehicle setup. In conclusion a recommendation for the shape of a frequency continuous (frequency sweep) excitation signal is given based on the identified excitation spectra.