The Study Of Bell-shaped Vibratory Gyro

A gyro is the critical core component responsible for measuring the angular rate of a carrier.In tunneling,mining,underground pipeline placing,and conventional artillery guidance applications,the carrier(drilling mechanism,projectile,etc.)is subject during its motion to a severe environment of high overloading and high spinning,hence arising a pressing need for a gyro that offers a high overload capacity and a wide measuring range.Inspired by the traditional Chinese bell and having regard to the work principle to a metal shell vibratory gyro,this paper proposes a Bell-Shaped Vibratory Angular Rate Gyro(abbreviated as BVG)that meets the aforesaid requirements.The study in this paper focuses on theoretical modeling of BVG,bell shaped resonator characteristic analysis,its structure optimization,and its signal processing method.The study largely includes:(1)A BVG is proposed,and an insight is provided inside the oscillation mode and the motion model.Bell shaped resonator dynamic formulas are developed for the situation where an input angular rate exists,and the natural frequency of the bell shaped resonator and its precession factor are deduced,hence placing a theoretical basis for BVG.(2)Bell shaped resonator are analyzed in their natural frequency,oscillation mode precession,high overloading resistance,and electro-mechanical coupling behaviors.The structure of BVG is studied for optimization,and optimization indices and restraint relationship are postulated for bell shaped resonator structures.A bell shaped resonator structure is devised,which allows physical characterization from a bell shape resonator mathematic model to a gyro but;this also solves the tricky problem with direct angular rate measurement in an environment of wide measuring range and high overloading.(3)BVG are analyzed for their signal characteristics.An equivalent control model is built for gyros,with the model parameters being subsequently identified.An integrated signal processing technique,based on self-adaptive smooth model variable structure controller,is advanced to cope with the solution difficulty with existent control and measurement techniques under a high spin speed condition,which helps solve the problem that the performance of gyros cannot be guaranteed at a high spinning speed.(4)A BVG prototype was fabricated and tested.The results show that measuring range is ±3600°/s,resolution is 0.06°/s,bias stability is 7.862°/h,scale factor nonlinearity is 0.118%,and overload resistance is 12000 g,which show theoretic analysis' s correctness.