Digital control and performance test of a symmetrical doubly decoupled micro-machined gyroscope

This paper describes a system for digital signal processing to control vibrating gyroscopes which will allow more flexibility and increase performance through a reduction in electronics noise. A close-loop control method based on quadrature demodulation (QD) is presented. Improvements in signal demodulation, noise suppression, phase shift and direct digital frequency synthesizer (DDS) are also proposed. The whole open-loop system is implemented on a FPGA (field programmable gate array) platform and tested. The resulting scale factor and nonlinearity are 7.1 mV/°/s and 0.55% respectively with the full scale of 400°/s.