Relationship Between Zero-Rate Output and the MEMS Element in a Closed-Loop System

This paper analyzes how zero-rate output (ZRO) arises in the response signal of a MEMS gyroscope. ZRO challenges the performance of MEMS gyroscopes, and in order to avoid it by design, knowledge of its cause is important. In this paper, the most relevant error sources are analyzed at the signal path level, which is a more general approach than focusing on specific designs. An analysis underscores the general understanding, which is necessary in order to improve the overall performance and the robustness of MEMS gyroscopes. A method to approximate nonlinear models through the coupling of two linear models is presented. The quality of the approximation and the necessary preconditions are shown. The theoretical results are verified by numerical simulations. An extension of the model to other nonlinearities is also discussed. With this approximation, the signal paths in the system, and especially those caused by the nonlinearity, lend themselves to an analysis.