Abstract
This paper presents an investigation on the sensitivity enhancement of a resonant accelerometer by operating it in the nonlinear regime. The accelerometer is excited by a DC load superimposed to an AC harmonic load. The electric load is tuned such that the accelerometer is driven at primary resonance with a softening-type behavior. Upon the application of a small acceleration, the nonlinear resonance frequency of the accelerometer shifts to a smaller value. This frequency shift is used as an indication for the detected acceleration. This shift is much larger compared to the shift of the resonance frequency of the accelerometer when operating in the linear regime. The concept of the nonlinear excitation is demonstrated by simulation on a commercial capacitive accelerometer. A nonlinear single-degree-of-freedom (SDOF) system is used to model the accelerometer. Several results are shown for the effect of the DC and AC voltages on enhancing the sensitivity of the accelerometer.