Eigenmode Based Optimization of Sensors

Abstract

Immunity failures of safety-critical automotive sensors can often be linked to strong resonances. In traditional approaches to combat the resonance, it is either shifted to other frequencies or attenuated. In this paper, a third way is shown. Every resonance is associated with an eigenmode of the system. If externally excited, the mode may resonate with a certain amplitude. This amplitude is a function of the projection of the system’s excitation onto the spatial distribution of the mode.With the help of a 3D sensitivity analysis, we identify potential geometric parameters that lead either to a reduced excitation of the eigenmode or that lower the impact of the eigenmodes on the target signal.Applying this method to an automotive pressure sensor a significant reduction of the resonance amplitude by a small modification in the sensor layout is achieved.