H∞ controller design of MEMS gyroscope and its performance test

In this paper, proposed is a feedback controller for MEMS gyroscope using H_∞ control scheme and presented is the experimental performance test result with closed loop fabricated using discrete analog circuits. Since MEMS gyroscope is operated at its resonant frequency, its high quality factor limits the bandwidth of the gyroscope when it is operated under an open loop condition. To improve the bandwidth of the gyroscope, an H_∞ controller is proposed. The performance of the proposed controller is analyzed using frequency response, computer simulation and experiment with analog circuits fabricated using discrete elements. The analysis and test results show that the proposed controller improves much the performance of the MEMS gyroscope in that the bandwidth is enlarged and the linearity is enhanced. It is also shown that the proposed H_∞ controller is more robust over unmodeled dynamics comparing with the controller with PID scheme.