Research On Drive And Detection Technology Of Quartz Tuning Fork Gyroscope

Gyroscopes are indispensable in navigation, guidance, stabilization and collimation systems. A quartz tuning fork gyro uses a double-ended tuning fork to sense the angle rate. It is widely applied in low precision inertia measure field, because of its tiny bulk, low power consumption and high reliability. The mass in this gyro is so tiny that it is extremely challenging to design a high performance drive and detection circuits.The drive and detection system of the quartz tuning fork gyro is demonstrated in this dissertation. Researches that have been completed are shown as follows:1. Relationship between the gyro's bandwidth and sensitivity and the resonant frequency differential ratio is derived through frequency analysis. The bandwidth of the gyro increases as the resonant frequency differential ratio increases; but the sensitivity decreases as the resonant frequency differential ratio increases. This important conclusion will help to choose appropriate resonant frequencies for drive and detection modes when designing a gyro.2. Influences of the mechanical coupling on the parameters of this gyro are presented. Simulations show that the bias, range and sensitivity of the gyro are seriously influenced by the mechanical coupling.3. A resonant drive control system is designed. And an automatic gain control (AGC) loop is introduced to keep the vibrating amplitude of dive tines invariable. It will effectively improve the linearity and robustness of the gyro. Moreover, the configuration of the drive circuit is illustrated in detail.4. A signal detection system based on the correlation detection technique is designed. And the configuration of the detection circuit is illustrated in detail.5. Referring back to the foregoing design approaches, a quartz rate sensor has been fabricated and tested on a rotating floor. The resolution of the sensor is 0.56°/s. The scale factor (or sensitivity) is 44.5mV/(°/s). The linearity is 1.86%. The bias stability is 2.4°/s.