Single-Channel Control for Hemispherical Resonator Gyro Based on Time Division Multiplexing and Demultiplexing

With the feature of high precision, strong reliability, and long life, hemispherical resonator gyro (HRG) has a broader prospect in the field of inertial navigation. However, the electrical gain (EG) and electrical phase (EP) between the two control channels in whole angle mode operation are usually unbalanced, which inevitably lead to drift error in the output angle of gyro. In this paper, the analysis of angle drift error in circumferential range from 0 degree to 90 degree caused by EG unbalance and EP unbalance is conducted theoretically and verified by experiments. To deal with the problem of electrical unbalance, a single-channel control strategy based on time division multiplexing and demultiplexing is proposed. Compared with the traditional dual-channel control, the single-channel control can fundamentally eliminate the angle drift error caused by both EG unbalance and EP unbalance and suppress the peak-to-peak value of angle drift error by 5x. What’s more, the proposed single-channel control strategy can also achieve reducing the cost, size, weight, and power (CSWaP) of gyro control system, which is beneficial to HRG miniaturization.