Stability of Operating Noise for Packaged MEMS Gyroscopes in Low-Speed Vehicle Motion Scenarios

Micro-Electro-Mechanical System (MEMS) gyroscopes serve as core components for attitude-sensing systems in low-speed unmanned vehicles and mobile robots. The long-term dynamic stability of MEMS gyroscopes under actual continuous low-speed vehicle operation is significantly inferior to the nominal performance derived from laboratory-based static calibration. This paper adopts a navigation-grade fiber optic gyroscope as the high-precision angular velocity reference. Angular velocity error sequences between the MEMS gyroscope and fiber optic gyroscope are established using field test data collected from a low-speed vehicle experiment lasting approximately 3.3 h. Three analytical approaches are applied to systematically characterize noise evolution features of the MEMS gyroscope under static and dynamic conditions from multiple dimensions. These approaches include time-domain drift analysis, angle random walk evaluation via Allan Variance, and frequency-domain interpretation based on Welch power spectral density. The test results reveal that vehicle motion significantly degrades the 10 s averaged bias stability of the MEMS gyroscope. The bias stability values under dynamic conditions increase by 2.1, 2.7 and 7.7 times compared with static states respectively. Root mean square analysis through band segmentation integration of Welch power spectral density indicates that vehicle motion induces the most obvious rise in noise energy in the middle frequency band. The amplification factor of noise along the Y axis reaches 24.7 times. The joint analytical framework proposed in this paper takes fiber optic gyroscope measurements as the reference and integrates time-domain analysis, Allan Variance and frequency-domain methods. It can provide sufficient experimental evidence and technical support for dynamic error compensation of MEMS gyroscopes deployed on low-speed mobile platforms.