Multi stage control architecture for error suppression in micromachined gyroscopes

摘要

Due to restrictive tolerancing, structural imperfections that reduce performance of fabricated micro gyroscopes are typical. While feedback control is normally used to compensate for these imperfections, there are limitations to how large of errors for which this strategy can compensate without interfering with the performance of the sensor. A multi stage control architecture comprising in situ self-diagnostic capabilities, electronic "trimming" of errors, and feedback control allows for the compensation of all magnitudes of errors without interfering with the performance of the device. The self-diagnostic capabilities include an algorithm for determining structural imperfections based on the dynamic response of the system. The feedforward portion of the control is used to "trim" large imperfections, while the feedback portion compensates for the remaining non-idealities and small perturbations. A control architecture is shown in a gyroscope using nonlinear electrostatic parallel plate actuation.