Design of a digital closed control loop for the sense mode of a mode-matching MEMS vibratory gyroscope

This paper presents a digital closed loop control method for the sense mode of a mode-matching MEMS vibratory gyroscope. The sense closed loop system reported in our previous work is relatively complex and unreliable due to the existence of notch filter. In this work, a more simple and robust control system is realized with the help of mode-matching control. With a tuning voltage automatically applied on the tuning combs of the gyroscope, a frequency split of less than 0.3 Hz is achieved. Experimental results show that the mode-matched gyroscope achieves a scale factor of 18.5mV/deg/s with a nonlinearity of 0.088% and a bias instability of 2.7deg/h.