Abstract:The cylindrical vibrating gyroscope (CVG) is a type of vibrational gyro measuring the angular velocity or angle of the carrier based on the Coriolis effect. It has the advantages of high precision, small size, simple structure, and low power consumption, which is an ideal gyroscope for the inertial navigation system. The common working modes for CVG comprise the force to rebalance (FTR) mode and the whole-angle ( WA) mode. In the spacecraft attitude determination and other applications requiring high precision and small measurement range, the FTR mode is advantageous in outputting angular rate information, good noise characteristics, drift error compensation and high resolution. This paper first introduces the basic principle of the frequency tracking loop, the amplitude control loop, the orthogonal control loop, and the force to balance control loop. The frequency tracking loop and the amplitude control loop constitute the main mode control loop of the gyroscope, which is responsible for the frequency and amplitude control of the system. The orthogonal control loop and the force balance control loop constitute the control loop of the sensitive mode, which is responsible for the suppression of the orthogonal error, the suppression of the sensitive mode and the extraction of the angular rate information. The simulation of closed-loop control in force to balance mode is then realized.