Correction of the Angular Gain Through in-Operation Compensation of Nonlinearity in MEMS Rate-Integrating Gyroscopes

This work proposes a compensation mechanism for nonlinearities in MEMS rate-integrating gyroscopes (RIGs). Following an initial calibration of the nonlinear stiffness terms, the method applies real-time forces to counteract their effect. Applied to both axes of a 30-µm-thick dual Foucault pendulum MEMS structure, the technique reduces the first four harmonics in the frequency spectrum of the precession rate by at least one order of magnitude. In turn, it enables independence between the effective angular gain in operation and the target displacement, which can thus be increased to 0.5 µm with a residual error of only ±35 ppm in the measured angular gain, and an angle white noise of 100 × 10−6 °/ √Hz.