Real-Time Identification and Compensation of Phase Error for Whole-Angle Hemispherical Resonator Gyroscope Based on Forgetting Filter and Virtual Rotation

The drive, sense, phase, anisoelasticity, and anisodamping errors of whole-angle hemispherical resonator gyroscope (WA-HRG) have the temperature dependence. Among these errors, the phase error is the most seriously affected by temperature, and severely affect WA-HRG’s full-temperature performance. A real-time identification and compensation method for WA-HRG phase error based on forgetting filter and virtual rotation is proposed in this paper. This method is experimentally verified in a 10^∘C to 40^∘C temperature cycle. The phase error’s real-time identification and compensation is able to maintain the convergence by the forgetting filter. The sense-mode control voltages’ coupling is amplified by the imposed virtual Coriolis voltage and is suppressed by the phase error compensation. This paper also experimentally verifies the variation of the anisoelasticity with temperature, the frequency difference at 10^∘C, 25^∘C, and 40^∘C are 1.1788, 1.1974, and 1.2386 mHz. The further online elimination of the frequency difference and compensation of the phase error will completely eliminate the angle-dependence bias (ADB) generated by their coupling.