Abstract
KEYWORDS:
Vibrational simulation, modelling, state space, data acquisition, FFT.
ABSTRACT:
More and more the vibrational restrictions on vehicle parts are becoming one of the most important points to be taken into account in design. This matter is especially remarkable on the rear view mirror, where not only comfort conditions but legal and safety ones are to be considered. On this paper we propose the use of system identification procedures in order to obtain a mathematical model of the mirror which allows us to arrange virtual simulations and to support CAD-CAE techniques. This way we can foresee the response of the mirror when being excited by different input signals, without affording the high costs derived from real testing (financial and time-consuming). The method proposed is obtained by empirical CAD-independent procedures. By testing different samples raw input-output data is obtained. This is taken as a starting point for our mathematical model. And therefore, after filtering and selecting the sensor information, we arrange a state-space system identification method with a least square error resolution algorithm, which can be of two types: forcing a definite symbolic model so that we can resolve some physical parameter of the system; or calculating different order systems for subsequently selecting the one which best matches the real model with the minimum system order. The results obtained show the availability of this method for virtual testing arrangement and for obtaining physical descriptors of the OSRVM (Out-Side Rear View Mirror).