Development and Testing of a Dual Accelerometer Vector Sensor for AUV Acoustic Surveys

Abstract

This paper presents the design, manufacturing and testing of a Dual Accelerometer Vector Sensor (DAVS). The device was built within the activities of the WiMUST project, supported under the Horizon 2020 Framework Programme, which aims to improve the efficiency of the methodologies used to perform geophysical acoustic surveys at sea by the use of Autonomous Underwater Vehicles (AUVs). The DAVS has the potential to contribute to this aim in various ways, for example, owing to its spatial filtering capability, it may reduce the amount of post processing by discriminating the bottom from the surface reflections. Additionally, its compact size allows easier integration with AUVs and hence facilitates the vehicle manoeuvrability compared to the classical towed arrays. The present paper is focused on results related to acoustic wave azimuth estimation as an example of its spatial filtering capabilities. The DAVS device consists of two tri-axial accelerometers and one hydrophone moulded in one unit. Sensitivity and directionality of these three sensors were measured in a tank, whilst the direction estimation capabilities of the accelerometers paired with the hydrophone, forming a vector sensor, were evaluated on a Medusa Class AUV, which was sailing around a deployed sound source. Results of these measurements are presented in this paper.

Validation of a method to measure the vector fidelity of triaxial vector sensors

“…However, if the pointing accuracy is less than or of the same magnitude as the uncertainty in misalignment angles (suggested by equation ( 2)), then there is no compelling reason to correct Θ out . Given the pointing accuracy of and the resolution demonstrated here, the results for No Tilt were corrected using (19) to show a consistent pointing accuracy over 4π solid angle of 0.13 • . It is possible to iterate the output via a second (or more correction steps) by recalculating a new M from Θ corr using ( 6) and row-normalising towards the lowest possible pointing error.…”

Verification of Data from Supersensitive Detector of Hydrosphere Pressure Variations

“…Many developers of offshore systems [ 5 , 6 , 7 ] use these methods. In other experiments, we used commercially produced devices in the same housing as those of our creation [ 8 , 9 ]. Recently, a similar technique has been used in the application of neural networks [ 10 , 11 , 12 ].…”

Dual Band MEMS Directional Acoustic Sensor for Near Resonance Operation

“…An alternative to microphone arrays is vector sensors. They can achieve accurate directional response relying on many different techniques and configurations and appropriate signal processing schemes [ 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 ]. More recently, the reduced size, lightweight, and lower power requirements of MEMS-based directional acoustic sensors fostered interest in their development [ 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 , 31 , 32 , 33 , 34 , 35 , 36 , 37 , 38 ].…”