Robust optimization of an automobile rearview mirror for vibration reduction

An automobile outside rearview mirror system has been analysed and designed to reduce vibration with a finite element model, Modal analysis is conduct ed for the calculation of natural frequencies. Harmonic analysis is utilize d to estimate the displacements of the glass surface under dynamic loads. T he model is verified with the vibration experiment for the parts and the as sembled body. The structure of the mirror system is optimized for robustnes s defined by the Taguchi concept. At first, many potential design variables are defined. Final design variables are selected based on the amount of co ntribution to the objective function. That is, sensitive variables are chos en. The signal-to-noise (S/N) ratio in the Taguchi method is replaced by an objective function with mean and standard deviations of the quality charac teristics. The defined objective function is appropriate for structural des ign in that the vibration displacements are minimized while the robustness is improved.