Research Progress of Surface Acoustic Wave Gyroscope

High-precision inertial navigation system is one of the keys for underwater vehicles to successfully complete underwater operations. As an important inertial sensing element, gyroscope is the basic core component of inertial navigation system. The gyroscope based on the surface acoustic wave (SAW) gyroscopic effect has attracted great interest due to its excellent vibration resistance, good reliability and stability, and has a good application prospect in harsh environments. In this paper, the research progress of SAW gyroscope is reviewed, especially the gyroscope with metallic dot array is introduced. The structure consists of two SAW sensor elements placed in opposite directions on the same piezoelectric crystal, and metallic dot array is distributed in the middle of the interdigital transducer. Combined with the research method of acoustic wave transmission characteristics in layered medium, the influence of piezoelectric crystal and metallic dot array on the response characteristics of the sensor was modeled and analyzed. Then SAW gyroscopes with working frequency of 30MHz, 80MHz and 95MHz were designed and developed. The experimental results show that the gyroscope achieves good temperature compensation characteristics, and the detection sensitivity of the sensor is greatly improved by the metallic dot array which is reasonably set on the SAW propagation path.