Theoretical investigation of the mechanical coupling in a differential vibrating beam accelerometer

The mechanical coupling between two beams which leads to a blind zone has emerged as an important issue in the design and testing of the high-precision differential vibrating beam accelerometer. This paper presents a chain-like mass-spring model for the mechanical decoupling in a differential VBA and derives the fundamental equations by matrix operation to describe their frequency behaviors. The mechanical uncoupled conditions are obtained and their potential applications on the differential VBA are analyzed. The blind zone performance of the differential VBA is studied and the more realistic design rules for reducing the blind zone and the common parasitic sensitivities simultaneously are obtained.