Solid-state motion sensors on acoustic waves. Theory and experiment

The Effect of a Rotating Medium on Bulk Acoustic Wave Polarization: From Theoretical Considerations to Perspective Angular Motion Sensor Design

“…The authors note that a longitudinal wave propagating along the axis of rotation does not change its polarization, and a transverse wave is a combination of two circularly polarized waves with different velocities. This assumption was confirmed by a series of previous studies including a recent contribution by our research group [18,19].…”

“…For the first special case, several concepts were proposed, test models of the AMS SE were made and the experimental results confirmed the theoretical principles [18,19].…”

The Sensitive Element of Acoustic Sensor on Circular Polarized Waves: From Theoretical Considerations towards Perspective Rotation Rate Sensors Design

“…According to the expressions obtained by the authors earlier [ 16 , 17 ], in the presence of rotation, when the acoustic duct is exposed to centripetal and Coriolis accelerations, the phase velocity of CPAW is proportional to the rotation rate of the propagation medium, and depending on the direction of particles oscillation in waves (clockwise or counterclockwise), it either increases or decreases. As a result, when the set of CPAW propagates in a rotating medium, the displacement vector of the total linearly polarized wave rotates through an angle α proportional to the angular velocity and the wave propagation time, where V 0 is a total wave phase velocity without rotation.…”

“…According to the earlier calculations [ 16 , 17 ], the directions of particle motions in the emitted waves are the opposite. As a result, under rotation of the acoustic lines about the X -axis of CPAW propagation, the phase velocity of one of them receives a positive addition V 1 = V 0 /((1 + Ω/ω)), and the other—the negative one V 2 = V 0 /((1 − Ω/ω)).…”

“…In recent years, the research group of the Department of Electroacoustics and Ultrasonic Technology of Saint Petersburg Electrotechnical University has been searching for the latest solutions in this scientific field, conducting complex theoretical, computational, and experimental studies. The characteristics of acoustic wave dependent on rotation rate were first discovered, thereby, revealing the possibility of using various types of acoustic waves in the presence of the rotation of the propagation medium for RRS SE development [ 16 , 17 ]. The authors proposed a number of fundamentally new physical principles and constructive solutions for RRS SE design, based on acoustic waves, where the informative parameter is the change in the characteristics of propagating acoustic waves from the rotation rate [ 18 ].…”