Microelectromechanical Hybrid Gyroscope Design of Closed-Loop Detection Circuit Based on FPGA

Abstract

This paper presents a new microelectromechanical hybrid gyroscope (MHG) with three equilibrium rings. This structure can eliminate the error caused by the double rotation frequency of the driving shaft successfully. The MHG kinematic equations with three equilibrium rings are derived in this paper. Meanwhile, a new digital design and simulation of the MHG closed-loop detection circuit are proposed based on FPGA. The noise interference is weakened by using differential mode signal detection and the resources of FPGA are decreased by the loop diode demodulation in this paper. The cross axis coupling of the decoupled system is about 2.4%. The phase margin is 70deg and the magnitude margin is 22db after correction. The transcient response simulation is tested when the inputs are sinusoidal functions. The bandwidth and scale factors of x-axis and y-axis closed loops are analyzed in the paper. The bandwidth can reach about 70Hz and the scale factors of x-axis and y-axis closed loops are 0.1467V/o/s and -0.1467V/o/s respectively.