A temperature self-calibrated MEMS gyroscope with 0.007°/h/K bias drift coefficient using real-time parametric quality factor control and mode matching

Both mechanical and electrical errors contribute to the zero-rate output (ZRO) of MEMS gyroscopes, which mainly include quadrature error leakage into the in-phase channel and in-phase errors originating from force misalignment, electrical feedthrough, and damping mismatch between the gyroscope drive mode and sense mode. A new self-calibration control scheme for the gyroscope's ZRO based on parametric excitation (PE) quality factor control and mode matching is proposed in this paper, featuring the advantages of simultaneously suppressing the impact of electrical feedthrough, force misalignment and real-time compensating for the effective sense mode quality factor drift due to temperature variations, providing a practical solution to achieve low temperature sensitivity of ZRO for high-performance MEMS gyroscopes. As a result, the bias instability (BI) decreases from 0.295 °/h to 0.156 °/h over the temperature range of -20°C to 50 °C, while the rate random walk (RRW) decreases from 0.0038 °/√(h³) to 0.0014 °/√(h³), a 2.7-fold reduction. The temperature coefficient of bias drift with self-calibration decreases from 0.864 °/h/K to 0.007 °/h/K with a reduction of 122 times, which is the best value reported publicly to date.