Optomechanical system design under road vibration conditions

Optomechanical systems used in vehicles or moving platforms are exposed to vibration loads from road effects. This study investigated the dynamic behavior of an optomechanical system exposed to random vibrations. Random vibration analysis and laboratory tests of the system were performed with the MIL-STD-810 test method standard. The relative displacements of two lenses in the optomechanical system were obtained under vibration loads by using the finite element (FE) method. The displacements were examined by tests. The obtained relative displacements of the lenses were used as input to the optical analysis and the laser spot position was obtained. The obtained spot positions were evaluated comparatively with the tests. The optical analysis results were consistent with the tests. Using the verified FE and optical models, structural modifications were made in the basic design. Five different design changes were examined. The natural frequencies and the mass of the entire system and the relative displacements of the lenses were obtained for comparative evaluation. Finally, the optimum design minimally affected by vibration loads was achieved.