Patent attributes
A hemispherical resonator gyro includes: a vibration mode shape extractor to extract, based on sine and cosine wave signals corresponding to an actuator drive frequency and radial displacement of a hemispherical resonator, a vibration mode shape excited in the hemispherical resonator; a drive frequency corrector to cause, based on a resonance phase characteristic of the hemispherical resonator, the actuator drive frequency to match resonance frequency of the hemispherical resonator; a nodal quadrature vibration controller to generate, based on a vibration amplitude of a nodal quadrature vibration and azimuth orientation of wave antinode of a resonance mode, an actuator DC drive signal to suppress the nodal quadrature vibration; and a resonance controller to generate an actuator AC drive signal to control the vibration amplitude to be a constant value, and detect a rotational angle in an angle measurement axis direction from the azimuth orientation of wave antinode of the resonance mode.
