Development of autonomous underwater vehicle 'AQUA EXPLORER 2' for inspection of underwater cables

Kojima, Junichi; Kato, Yukitaka; Asakawa, Kenichi; Matumoto, S.; Takagi, Satoshi; Kato, Nobuo

doi:10.1109/oceans.1997.624128

Cited by 23 publications

(7 citation statements)

References 7 publications

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“…-Change in the M: In this approach, the idea is to control the total mass of the vehicle, which can be achieved by: either using the dead weights (e.g., AQUA EXPLORER-2 AUV used two dead weight releaser each of 2 kg, Kojima et al [19]) or using the ballasting/de-ballasting of buoyancy tanks that are carried inside the AUV/AUGs hull.…”

Section: Module 12-methodology To Control the Buoyancymentioning

confidence: 99%

Design and Analysis of a Variable Buoyancy System for Efficient Hovering Control of Underwater Vehicles with State Feedback Controller

Tiwari

Sharma

2020

JMSE

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The design process for Variable Buoyancy System (VBS) is not known in full, and existing approaches are not scalable. Furthermore, almost all the small size Autonomous Underwater Vehicles/Gliders (AUVs/G's) use very low capacity of buoyancy change (in the range of few milliliters) and the large size AUVs require large buoyancy change. Especially for adverse weather conditions, emergency recovery or defense-related applications, higher rate of rising/sinking (heave velocity) is needed along with an ability to hover at certain depth of operation. Depth of UVs can be controlled either by changing the displaced volume or by changing the overall weight and, herein, our focus is on the later. This article presents the problem of design and analysis of VBS for efficient hovering control of underwater vehicles at desired depth using the state feedback controller. We formulate and analyze the design and analysis approach of VBS using the fundamental of mechanics, system dynamics integration and control theory. Buoyancy is controlled by changing the overall weight of the vehicle using the ballasting/de-ballasting of water in ballast tanks through the use of Positive Displacement Pump (PDP) for control in heave velocity and hovering depth. Furthermore, detailed mass metric analysis of scalable design of VBS for different buoyancy capacities is performed to analyze the overall performance of the VBS. Also, the performances of AUVs integrated with VBS of different buoyancy capacities are investigated in both the open loop and closed loop with the LQR state feedback controller. Hovering performance results are presented for three Design Examples (DEs) of AUVs with 2.8 m, 4.0 m and 5.0 m length and they are integrated with various buoyancy capacities at 9 kg/min rate of change of buoyancy. Results indicate that the AUVs achieve the desired depth with almost negligible steady state error and when they reach the desired hovering depth of 400 m the maximum pitch angle achieved of 16.5 degree for all the Des is observed. Maximum heave velocity achieved during sinking is 0.44 m/s and it reduces to zero when the vehicle reaches the desired depth of hovering. The presented computer simulation results indicate good performance and demonstrate that the designed VBS is effective and efficient in changing the buoyancy, controlling and maintaining the depth, controlling the heave velocity and can be used in rescue/attack operations of both the civil and defense UVs.Keywords: variable buoyancy system (VBS); autonomous underwater vehicle (AUV); positive displacement pump (PDP); brush-less direct current (BLDC) motor; linear quadratic controller (LQR)This scene demands vehicles that can be used for surveying the oceans for high endurance and operable at high depths. These requirements have motivated the researchers to design and develop new age Underwater Vehicles (UVs). UVs are designed to perform underwater survey missions such as detecting and mapping submerged wrecks, rocks and obstructions that can pose a hazard, primarily for efficient ...

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Section: Module 12-methodology To Control the Buoyancymentioning

confidence: 99%

Design and Analysis of a Variable Buoyancy System for Efficient Hovering Control of Underwater Vehicles with State Feedback Controller

Tiwari

Sharma

2020

JMSE

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“…The second-generation AUV called the AQUA EXPLORER 2 (AE-2) has a low bit rate acoustic link to communicate non-video data and a high bit rate for video signal transmission [Kojima97]. The low bit rate is 125bps using an FSK modulation.…”

Section: Selected Modem Implementationsmentioning

confidence: 99%

Underwater Acoustic Data Communications for Autonomous Platform Command, Control and Communications

Shinego¹,

Edelson²,

Menas³

et al. 2001

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“…A magnetic signal emitted from the cable is sampled in two different points in space and attenuates at a faster rate because of the salinity of sea water. The magnetic field signal can thus be measured only in close proximity from the source, and in practice the signal can only be measured within a 5 m range (Takagi et al 1996;Kojima et al 1997;Szyrowski et al 2013b). This creates a problem in marine survey, as it has to be performed by a remotely operated vehicle or a specialized driver and thus susceptible to increases in operational cost and risks to human health and life.…”

Section: Introductionmentioning

confidence: 99%

Subsea cable tracking in an uncertain environment using particle filters

Szyrowski

Sharma

Sutton

et al. 2015

Journal of Marine Engineering & Technology

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Localization of subsea cables is a demanding and challenging task. Among the few methods reported in the literature, magnetic field detection is the most promising one, as the cable does not require to be seen visually. Magnetic noise and a quick attenuation of the magnetic field propagating in sea water often make available methods unreliable. The authors propose a novel method of using particle filters for estimating the position of a subsea cable in a highly uncertain environment. The method was tested on data collected from a buried cable in the Baltic Sea, Denmark and shown to have a close approximation to the true location of the subsea cable. The method can be used to localize a subsea cable in an offshore noisy and uncertain environment and provides an inexpensive alternative to the use of a diver or a remotely operated platform.

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Development of autonomous underwater vehicle 'AQUA EXPLORER 2' for inspection of underwater cables

Cited by 23 publications

References 7 publications

Design and Analysis of a Variable Buoyancy System for Efficient Hovering Control of Underwater Vehicles with State Feedback Controller

Design and Analysis of a Variable Buoyancy System for Efficient Hovering Control of Underwater Vehicles with State Feedback Controller

Underwater Acoustic Data Communications for Autonomous Platform Command, Control and Communications

Subsea cable tracking in an uncertain environment using particle filters

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