Temperature Adaptability Of Digital Control Circuit And Dynamic Characteristic Study For Hemispherical Resonator Gyro

The hemispherical resonator gyro (HRG) is a kind of solid state gyroscopes withfeatures of high accuracy, long life span, high reliability, and radiation hardness. Withits excellent performance, the HRG is widely used in the field of space exploration. Atpresent, there is a big gap between our country and foreign countries in performance ofHRG. Therefore, it is of great necessity to research on improving the performance ofHRG. The main works of this dissertation are as follows:1.Aiming at the temperature adaptability for the digital control circuit of HRG, thetemperature drift of each main module of the circuit is analyzed. Theoretical analysisshows that the drift caused by resistor and capacitor in the pre-filtering and differentialcircuit is the major factor for the temperature drift of the full circuit. To improve theaccuracy of the digital circuit and reduce the temperature drift, precision resistor andcapacitor can be used in the circuit.2.Temperature experiments for the digital control circuit are carried out to provethe correction of theory analysis. Results of the experiment are consistent with which oftheory analysis. And experiment result with precision resistor and capacitor shows thatthe temperature drift is reduced one order of magnitude, and the measurement accuracyof the circuit is improved one order of magnitude compared with common resistor andcapacitor.3.The theory analysis of bandwidth for HRG is carried out based on its dynamicequation. And the influences for the practical bandwidth of the gyro caused by eachmain module of the circuit are analyzed in detail. The value of practical bandwidth islow than the theoretical one. Theoretical analysis shows that the digital low pass filter inthe demodulation module and the PI parameter used in the velocity control loop ofdigital circuit are major factors in reducing the value of practical bandwidth.4.Aiming at the bandwidth of HRG, dynamic characteristic experiments are carriedout. The result shows that the practical value of bandwidth of HRG is below2Hz, and itis far less than theoretical value. To improve the bandwidth, the low pass filter and PIparameter should be optimized. Related experiments are carried out and validate thefeasibility of the method.