Separation, Identification, and Compensation of Damping, Detection, and Actuation Errors for Rate-Integrating Hemispherical Resonator Gyroscopes

Damping mismatch, detection error and actuation error are the primary sources of the output drift in rate integrating hemispherical resonator gyroscopes (HRGs). To date, separating the three errors remains a challenge, which hinders the accurate compensation of HRGs. This paper proposes a novel method to separate the damping, detection and actuation errors of HRGs. Theoretically, a dynamics model of HRGs considering the three errors is developed, where the detection and actuation errors are modeled using Fourier analysis. The effects of these three errors on the scale factor and the bias under different operation modes are discussed in detail for the first time. It is found that the three errors can be decoupled under the decay with quadrature control (DQC) mode, a special operation mode designed in this paper. In the experiments, by measuring the angle dependence of the scale factor and the bias of the energy loop, the damping, detection and actuation errors of three HRGs are successfully identified and then comprehensively compensated. For one typical tested HRG, after compensation, the angle-dependent error of the scale factor decreases from 1.08% to 0.036% by a factor of 30, the angle-dependent variation of the static drift reduces from 5.14×10<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">−3</sup> °/s to 2.37 ×10<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">−4</sup> °/s by a factor of 22, and the fluctuation of the dynamic output at different input rates decreases 14‒25 times. Our method can also be conveniently applied to other rate integrating Coriolis vibrating gyroscopes (CVGs).