Temperature Drift Compensation for Hemispherical Resonator Gyro Based on Natural Frequency

Abstract

Temperature changes have a strong effect on Hemispherical Resonator Gyro (HRG) output; therefore, it is of vital importance to observe their influence and then make necessary compensations. In this paper, a temperature compensation model for HRG based on the natural frequency of the resonator is established and then temperature drift compensations are accomplished. To begin with, a math model of the relationship between the temperature and the natural frequency of HRG is set up. Then, the math model is written into a Taylor expansion expression and the expansion coefficients are calibrated through temperature experiments. The experimental results show that the frequency changes correspond to temperature changes and each temperature only corresponds to one natural frequency, so the output of HRG can be compensated through the natural frequency of the resonator instead of the temperature itself. As a result, compensations are made for the output drift of HRG based on natural frequency through a stepwise linear regression method. The compensation results show that temperature-frequency method is valid and suitable for the gyroscope drift compensation, which would ensure HRG's application in a larger temperature range in the future.

The Study on Temperature Characteristics of a Monolithic Fused Silica Cylindrical Resonator

“…Furthermore, the temperature-frequency characteristics is highly linear, therefore it is possible to utilize one mode as a measure of gyroscope temperature for the compensation of the sensing mode [12]. Our group has designed and fabricated a monolithic fused silica cylindrical resonator that has high quality factor and small frequency mismatch [13], which is expected to be applied to the high precision inertial navigation and platform stabilization systems.…”

Full Digital Control of Hemispherical Resonator Gyro Under Force-to-Rebalance Mode

“…The frequency of HRG varies with temperature and each point of temperature only corresponds to one natural frequency. Therefore, instead of the temperature sensor, the temperature drift compensation can be accomplished based on the natural frequency of the resonator [12]. This compensation method was valid and suitable for the full digital circuit control.…”

“…But the natural frequency of HRG varies with the temperature. As mentioned in [12]- [14], the change rate of the natural resonance frequency of HRG with the ambient temperature is about 80ppm/°C. As the environment temperature changes, it is very difficult to produce the frequency which is the same as the natural resonance frequency ω of HRG.…”

A New Continuous Rotation IMU Alignment Algorithm Based on Stochastic Modeling for Cost Effective North-Finding Applications

“…Although Dynamically Tuned Gyros and Ring Laser Gyroscopes are suitable for precise north-finding, they are generally bulky and expensive [2,3]. In contrast, Coriolis vibration gyroscopes (e.g., a kind of cost effective medium precision Hemispherical Resonator Gyroscopes (HRGs) [4,5]) are generally compact and low-cost and suitable for a cost effective north-finding system. However, the drift errors of these gyroscopes are big problems, which limit the north-finding accuracy.…”