重力加速度计在硅微机械陀螺信号解调中的应用

Application of Gravity Accelerometer in Signal Demodulation Silicon of Micro-machined Gyroscope

硅微机械陀螺的一个重要应用是获取旋转载体的偏转方向,获取准确的旋转载体的自旋频率可以提高其解算精度。由于陀螺自身信号耦合了旋转载体做圆锥运动的频率,用其测得的自旋频率就包含了圆锥运动的频率。试验仿真了旋转载体在空间中做圆锥运动时不会对重力加速度计信号的频率产生调制作用,因此可以用重力加速度计测旋转载体的自旋频率,相对误差仅为1.25%;以地面作为参考坐标系,重力加速度计信号为参照信号,比较陀螺信号和重力加速度计信号的相位差,再减去相位差中含有的滞后值,进而可以计算旋转载体在空间中实际偏转方向。重力加速度计信号还可以确定旋转载体的舵相对地面坐标系的旋转角度。

It is an important application to get the deflecting direction by silicon micro-machined gyroscope. An exact self-rotation frequency can improve the precision of the deflecting direction. The signal of the gyroscope couples the frequency of the rotating carrier which makes the coning motion, so the frequency of the coning motion is contained when detecting the frequency of the rotating carrier using the signal of the gyroscope. The simulation result indicates that there is no frequency modulation for the gravity accelerometer signal when the rotating carrier make coning motion in the space, and the relative error is only 1.25% by detecting the self-rotation frequency of the rotating cartier using the gravity accelerometer. The earth＇s floor as the referenced coordinate system is needed, the gravity accelerometer signal as the referenced signal. Comparing with the output signal phase of the accelerometer and the gyroscope, subtracting the lagged value from the phase difference, the real deflecting direction of the rotating carrier in the space can be counted. The signal of gravity accelerometer also indicates the space positions of the rudder of the rotating carrier.