Full Vehicle Simulation Research Articles

Enhanced Multiaxis Vibration Control Using a Robust Generalized Inverse System Matrix

Multiaxis vibration control as a means to recreate service stress in the laboratory has achieved a great deal of success in the last decade. While initial applications centered around components and assemblies requiring a relatively few number of inputs (1 to 4), current applications such as a full-vehicle simulation may require 12 or more exciters. The complexity of the control process required to accurately reproduce the time history response for a full-vehicle simulation often requires that an expert operator intervene to coax the system into convergence. The time spent developing a control signal for a simulation test is costly in terms of both program timing and equipment wear and tear. Often compromises must be made due to the inability of the control system to create a fully accurate response given the available time and resources. This paper discusses the development and application of a new robust control technique that decreases operator interaction while improving control accuracy.

THE INCORPORATION OF TIRE MODELS INTO VEHICLE SIMULATIONS

Abstract After outlining the different requirements for tire models to be used in full vehicle simulations, a general tire interface to ADAMS will be presented. This interface consists of a library of different tire models and allows user-defined models, too. Special attention will be drawn to the determination of the Pacejka constants from standard tire measurements.

CORNERING ON UNEVEN ROADS

SUMMARY The cornering behaviour of the tyre and the vehicle on uneven roads has been studied both experimentally and theoretically. A simple pragmatic tyre model which is especially suitable to be used in vehicle simulation studies has been developed and compared with the adapted bare string tyre model. Both models show good agreement and also the models agree well with experimental results in the range of wavelengths not less than about two meters (i.e. about ten times the tyre contact length). Moreover, full vehicle simulations have been conducted in which the simple tyre model has been used and also road experiments with Volvo's experimental computer controlled suspension car where each suspension is excited to simulate road uneveness. It is concluded that a change may occur in understeer/oversteer nature on roads having short wavelength undulations through the decrease of average tyre side force. In case of undulations of rather long wavelength, the periodic variation of yaw rate appears to become rat...