Frequency tuning of a disk resonator gyro via mass matrix perturbation

Electrostatic tuning of the resonant modes in vibratory gyroscopes is often suggested as a means for compensating manufacturing aberrations that produce detuned resonances. In high performance sensors, however, this approach places very stringent requirements on the stability of the bias voltages used for tuning. Furthermore, the bias voltage stability must be maintained over the operating environment, especially with regard to temperature variations. This paper presents two methods for tuning the resonant modes in MEM vibratory gyroscopes using mass perturbation of the sensor´s resonant structure. The approach ameliorates the stringent bias voltage stability requirements and can be applied to any vibratory gyroscope that relies on modal frequency matching for optimum performance.