Doppler Velocity Log theory and preliminary considerations for design and construction

Performance Enhancement for Conventional Tightly Coupled INS/DVL Navigation System Using Regeneration of Partial DVL Measurements

“…The system model is constituted as a time-varying linear system by combining the differential equations for velocity and attitude errors obtained using Equations (1) and (2) can be defined as follows:…”

“…The measurement matrix H can therefore be designed as follows: 3 Journal of Sensors four axes of the DVL frame. The transformation matrix for body frame and DVL frame is as below [2]:…”

“…A DVL is used to measure the velocity of an underwater vehicle using the Doppler effect by observing the shift in frequency between an acoustic signal transmitted from the underwater vehicle and its echo signal reflected from the seabed. In a DVL, four transducers are aligned in a Janus configuration, whereby the velocity measured at each transducer is transformed into the three-axis velocity of the vehicle using a coordinate transformation matrix [2].…”

On AUV Control with the Aid of Position Estimation Algorithms Based on Acoustic Seabed Sensing and DOA Measurements

“…, M, where the acoustic beams reach the seabed. Precise calculation of these values even in the case of known seabed profile is not possible since it requires the precise values of the points x ij k , which depend on the unavailable precise AUV position X k due to Equation (8). The way to overcome this issue is to use the acoustic image data to estimate the seabed slope, i.e., the required partial derivatives of ψ(·).…”

“…Acoustic methods used in active mode give access to the distance measurements, which make the position estimation problem much easier, though in some areas of application such measurements are not acceptable or must be restricted due to the energetic or masking constraints [5].The possibility of the sonar employment in AUV navigation has already been mentioned by some authors either in application to the situation, when an accurate seabed map is available, or in the case of presence of significant seabed features [6]. Moreover, the active pinging can be used to determine one's speed over the seabed by tracking its features or by measuring the Doppler shift of returns [7], the same idea is used in the well-known DVL (Doppler velocity log) [8]. Moreover, acoustic sonars admit the usage of phased array technology, which permits to achieve the angular resolution up to 0.1 • [9].…”