Astatic Gyrocompass Based on a Hybrid Micromechanical Gyroscope

The kinematic diagram is presented and the principle of operation of an astatic gyrocompass based on a hybrid three-degree micromechanical gyroscope is described. The device determines the true azimuth of the longitudinal axis of a mobile ground object. At the same time, in contrast to gyrocompasses built on three-degree “heavy” gyroscopes on elastic or magnetic suspension of the motor, the device has low overall and weight characteristics and a lower level of power consumption. The device uses a modulation principle based on taking information about the angular motion of the rotor and creating control torques in a rotating coordinate system, which makes it possible to exclude such a significant disadvantage of the gyroscope as “zero shift In addition, the device has a higher measurement speed and has a higher immunity to base disturbances (vibration, shocks, shocks, etc.). A linearized mathematical model of a gyrocompass is constructed. It has shown that the error in measuring the angle of deviation of the instrument body axis relative to the plane of the true meridian is determining by the vertical component of the angular velocity of the Earth’s rotation and the damping coefficient of the precessional oscillations of the gyroscope. Technical solutions has proposed for compensation of these influences. Phase portraits have obtained for cases of symmetric and asymmetric rotor in the absence and presence of damping, as well as transient characteristics of the rotor motion for the same cases, which showed the presence of an oscillatory transient process with a significant decay time. An algorithm for reducing the measurement time based on the use of reversal points has proposed, as well as a technical solution that makes it possible significantly reduce the duration of the transient process by creating inertial damping along the measuring axis of the gyroscope.