Design of Oscillation Control Loop With Coarse-Precision Mode Transition for Solid-State Resonant Gyroscope

This paper presents a dual mode oscillation control loop design for a solid-state hemispherical resonator gyroscope (HRG) which uses the hemispherical vibrating shell for detecting the Coriolis force. A desirable control loop needs to be robust, fast, and also to have small driving and frequency noises which may cause significant errors, such as angular random walk. To design a fast and robust oscillation loop for precision gyroscope, a novel approach using a sequential resonance control mode transition is proposed in this paper. The coarse resonance control mode principally consists of phase shifter and limiter, which provides fast startup and tolerant tracking performances. The precision mode uses phase-locked loop for the sake of precision tracking performance. In addition, a theoretical analysis on the designed control loop considering mode transition is presented. In this paper, the tracking performances of the proposed loop are demonstrated via both simulation and experiments. The experimental results using a fabricated HRG verified the effectiveness of the proposed method.