Scale Factor Nonlinearity Suppression in Micromachined Resonant Accelerometers by Using an Improved Proportion F-Squared Method

In this paper, an improved proportion f-squared method (PFS) is proposed for the first time to reduce the nonlinearity error of scale factor in micro-machined resonant accelerometers (MRAs). The precision centrifuge test is firstly conducted to recognize the polynomial fitting model for further determination of a proportion factor, which can help achieve better cancelation of nonlinearity error, especially the quadratic residual error caused by imperfect symmetry of two resonators. The experiment results demonstrate a remarkable 50% decrease in the scale factor nonlinearity error, from over 23ppm to 12.5ppm within a ±20g measurement range, alongside improved linearity symmetry in both tests under the positive and negative input accelerations.