压电晶体切向对声表面波陀螺刻度因子的影响

刻度因子是陀螺的重要指标,而压电晶体切向对声表面波(SAW)陀螺刻度因子有重要影响。首先以铌酸锂作为分析声波波传特性的基板材料,建立不同的波传角度和不同的切面与各种模态SAW波速的物理数学模型,接着探讨旋转扰动时二次旋转欧拉角与X切、Y切及Z切等铌酸锂晶体中的陀螺效应,分析不同切向刻度因子的变化规律。根据计算结果,铌酸锂晶体中X切Y传(XY)、128°Y切X传(128°YX)、30°ZX、ZX和150°ZX对应的声表面波陀螺刻度因子最大,同时也得出了适合应用于声表面波陀螺的相对敏感切向为声表面波波速接近于慢横波时对应的切向。

Influence of Piezoelectric Crystal Cuts to the Scale Factor of Surface Acoustic Wave Gyroscope

The scale factor is an important index of gyroscope,and the cut of piezoelectric crystal has the material effect to the scale factor of surface acoustic wave gyroscope.The propagation characteristics over a piezoelectric half-space of LiNbO3 substrate were studied in this work firstly.The dependences of surface acoustic wave(SAW) phase velocity on the cutting axis and the propagation direction were discussed in physics mathematical model.Then gyroscopic effects on the revolving LiNbO3 crystal of X cuts,Y cut and Z cuts were discussed under rotational disturbance.The change rule of scale factor was analyzed under different cutting axis and different propagation directions.At last,through the calculation,the SAW gyroscope scale factor of XY,128°YX,30°ZX,ZX,150°ZX LiNbO3 crystal was much bigger and the applicable sensitive cuts which corresponded to the cuts when the SAW Phase velocity approached in the slow shear wave were determined.