An Improved Phase Lock Loop for Micromechanical Gyroscope with a Carrier Modulation

This paper presents an improved phase lock loop for a micromechanical vibrating gyroscope with a carrier modulation. The loop keeps the gyroscope working at the resonant frequency of its drive mode. Digital signal processing is adopted in design of the loop and Xilinx virtex4 series FPGA is used. Compare with the conventional way, it decreases the resources in FPGA including registers, LUTs, and DSP48s. The realization shows a reduction of 51.06% for registers, 52.68% for LUTs and 18.18% for DSP48s. Besides, the loop has good portability for different devices which have different resonant frequencies due to the fabrication error. No adjustment is needed unlike the conventional loop whose reference phase has to be adjusted manually.