A Drive Control Method for Silicon Micro-gyroscopes

The tracking ability of a silicon micro-gyroscope in a highly dynamic environment is a key factor for MEMS and inertial technology. To improve the tracking ability in a highly dynamic environment, a new drive control method for silicon micro-gyroscopes is proposed. First, a double closed-loop system with a phase-locked loop (PLL) and an automatic gain control (AGC) is designed to track the resonant frequency and stabilize the output amplitude. Second, the framework and corresponding algorithm of a second-order frequency-locked loop (FLL)-assisted third-order PLL were designed. Thereafter, the tracking performance characteristics of a third-order PLL and the proposed second-order-FLL-assisted third-order PLL at different frequency differences were simulated in Matlab Simulink. Simulation results show that the second-order-FLL-assisted third-order PLL can track the resonant frequency in a shorter time with a higher precision than the third-order PLL, and that the proposed method can still lock the resonant frequency of 11570 Hz when the frequency difference increases to 400 Hz, demonstrating its applicability in highly dynamic environments. Finally, the digital application specific integrated circuit (ASIC) test platform further validates the effectiveness of our proposed drive control method.