Characterization and Compensation of Detection Electrode Errors for Whole-Angle Micro-Shell Resonator Gyroscope

As for the whole-angle gyroscope, the detection symmetry along two axes is of significant importance to improve the gyroscope's performance. This paper presents the characterization and compensation of detection electrode error for the whole-angle micro-shell resonator gyroscope. The detection electrode errors including detection gain and angle errors mainly result from the assembly process of the micro-shell resonator and substrate electrode. The angle estimation errors, as a direct effect of detection electrode error, are investigated through experiments and theoretical analysis under different detection gain and angle errors. Besides, the consistency of experimental and simulation results proves that the sin and cos components of angle estimation error can be used to characterize detection gain and angle errors respectively. This angle estimation error not only has direct effects on the gyroscope's angle output but also results in the position error of applied actuation forces. Under this circumstance, the energy control force is observed to interfere with the free precession of the vibration pattern and produces additional angle drift. To eliminate the effects of the detection electrode error, the compensation parameters are identified based on the component analysis of the angle estimation error. After compensation, the bias instability has decreased from 0.118°/h to 0.041°/h and the scale-factor nonlinearity has been also improved by 36 times from 86.57ppm to 2.4ppm. [2021-0176]