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1 – 10 of 318Zhuoyu Zhang, Lijia Zhong, Mingwei Lin, Ri Lin and Dejun Li
Docking technology plays a crucial role in enabling long-duration operations of autonomous underwater vehicles (AUVs). Visual positioning solutions alone are susceptible to…
Abstract
Purpose
Docking technology plays a crucial role in enabling long-duration operations of autonomous underwater vehicles (AUVs). Visual positioning solutions alone are susceptible to abnormal drift values due to the challenging underwater optical imaging environment. When an AUV approaches the docking station, the absolute positioning method fails if the AUV captures an insufficient number of tracers. This study aims to to provide a more stable absolute position visual positioning method for underwater terminal visual docking.
Design/methodology/approach
This paper presents a six-degree-of-freedom positioning method for AUV terminal visual docking, which uses lights and triangle codes. The authors use an extended Kalman filter to fuse the visual calculation results with inertial measurement unit data. Moreover, this paper proposes a triangle code recognition and positioning algorithm.
Findings
The authors conducted a simulation experiment to compare the underwater positioning performance of triangle codes, AprilTag and Aruco. The results demonstrate that the implemented triangular code reduces the running time by over 70% compared to the other two codes, and also exhibits a longer recognition distance in turbid environments. Subsequent experiments were carried out in Qingjiang Lake, Hubei Province, China, which further confirmed the effectiveness of the proposed positioning algorithm.
Originality/value
This fusion approach effectively mitigates abnormal drift errors stemming from visual positioning and cumulative errors resulting from inertial navigation. The authors also propose a triangle code recognition and positioning algorithm as a supplementary approach to overcome the limitations of tracer light positioning beacons.
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Ling Chen, Sen Wang, Klaus McDonald‐Maier and Huosheng Hu
The main purpose of this paper is to investigate two key elements of localization and mapping of Autonomous Underwater Vehicle (AUV), i.e. to overview various sensors and…
Abstract
Purpose
The main purpose of this paper is to investigate two key elements of localization and mapping of Autonomous Underwater Vehicle (AUV), i.e. to overview various sensors and algorithms used for underwater localization and mapping, and to make suggestions for future research.
Design/methodology/approach
The authors first review various sensors and algorithms used for AUVs in the terms of basic working principle, characters, their advantages and disadvantages. The statistical analysis is carried out by studying 35 AUV platforms according to the application circumstances of sensors and algorithms.
Findings
As real‐world applications have different requirements and specifications, it is necessary to select the most appropriate one by balancing various factors such as accuracy, cost, size, etc. Although highly accurate localization and mapping in an underwater environment is very difficult, more and more accurate and robust navigation solutions will be achieved with the development of both sensors and algorithms.
Research limitations/implications
This paper provides an overview of the state of art underwater localisation and mapping algorithms and systems. No experiments are conducted for verification.
Practical implications
The paper will give readers a clear guideline to find suitable underwater localisation and mapping algorithms and systems for their practical applications in hand.
Social implications
There is a wide range of audiences who will benefit from reading this comprehensive survey of autonomous localisation and mapping of UAVs.
Originality/value
The paper will provide useful information and suggestions to research students, engineers and scientists who work in the field of autonomous underwater vehicles.
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This paper aims to provide details of underwater robot technology and its applications.
Abstract
Purpose
This paper aims to provide details of underwater robot technology and its applications.
Design/methodology/approach
Following an introduction, this article first discusses remotely operated vehicle (ROV) technology and applications and then considers their use in the emerging field of deep-sea mining. It then discusses autonomous underwater vehicle (AUV) technology and its applications, including sub-sea gliders. Finally, brief concluding comments are drawn.
Findings
ROVs were first developed in the 1950s for military applications. They are now widely used by the offshore oil and gas sector and other industries and are being developed for deep-sea mining. AUV technology has progressed rapidly in recent years and AUVs, including sub-sea gliders, are now emerging from their original role in oceanographic research and finding growing uses in the defence and offshore energy sectors.
Originality/value
This provides a detailed insight into underwater robot technologies, products and applications.
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This paper aims to provide details of recent developments in robots aimed at applications in the offshore oil and gas industries.
Abstract
Purpose
This paper aims to provide details of recent developments in robots aimed at applications in the offshore oil and gas industries.
Design/methodology/approach
Following a short introduction, this first discusses developments to remotely operated vehicles (ROVs) and autonomous underwater vehicles (AUVs). It then describes the Total-sponsored Autonomous Robot for Gas and Oil Sites (ARGOS) robot challenge. This is followed by a discussion of the Offshore Robotics for Certification of Assets (ORCA) programme. Finally, brief concluding comments are drawn.
Findings
Subsea residency and other techniques are being developed that will enhance the availability and capabilities of AUVs and ROVs and reduce their operating costs. Mobile robots that can operate in harsh topside rig environments to monitor and detect hazards arose from ARGOS and are being developed further prior to commercialisation. Bringing together academics and users, the collaborative ORCA programme is making significant progress in the development of aerial, topside and underwater robotic and sensing technologies for rig asset inspection and maintenance.
Originality/value
This paper identifies and describes key development activities that will stimulate the use of robots by the offshore industries.
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Behzad Taheri and Edmond Richer
Autonomous Underwater Vehicles (AUVs) play a crucial role in marine biology research and oceanic natural resources exploration. Since most AUVs are underactuated they require…
Abstract
Purpose
Autonomous Underwater Vehicles (AUVs) play a crucial role in marine biology research and oceanic natural resources exploration. Since most AUVs are underactuated they require sophisticated trajectory planning and tracking algorithms. The purpose of this paper is to develop a new method that allows an underactuated AUV to track a moving object while constraining the approach to a direction tangent to the path of the target. Furthermore, the distance at which the AUV follows the target is constrained, reducing the probability of detection and unwanted behavior change of the target.
Design/methodology/approach
First, a kinematic controller that generates a trajectory tangent to the path of the moving target is designed such that the AUV maintains a prescribed distance and approaches the target from behind. Using a Lyapunov based method the stability of the kinematic controller is proven. Second, a dynamic sliding mode controller is employed to drive the vehicle on the trajectory computed in the first step.
Findings
The kinematic and dynamic controllers are shown to be stable and robust against parameter uncertainty in the dynamic model of the vehicle. Results of numerical simulations for equidistant tracking of a target on both smooth and discontinuous derivatives trajectories for a variety of relative initial positions and orientations are shown.
Originality/value
The contribution of this research is development of a new method for path planning and tracking of moving targets for underactuated AUVs in the horizontal plane. The method allows control of both the direction of approach and the distance from a moving object.
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Abstract
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Alexandra Pereira Nunes, Ana Rita Silva Gaspar, Andry M. Pinto and Aníbal Castilho Matos
This paper aims to present a mosaicking method for underwater robotic applications, whose result can be provided to other perceptual systems for scene understanding such as…
Abstract
Purpose
This paper aims to present a mosaicking method for underwater robotic applications, whose result can be provided to other perceptual systems for scene understanding such as real-time object recognition.
Design/methodology/approach
This method is called robust and large-scale mosaicking (ROLAMOS) and presents an efficient frame-to-frame motion estimation with outlier removal and consistency checking that maps large visual areas in high resolution. The visual mosaic of the sea-floor is created on-the-fly by a robust registration procedure that composes monocular observations and manages the computational resources. Moreover, the registration process of ROLAMOS aligns the observation to the existing mosaic.
Findings
A comprehensive set of experiments compares the performance of ROLAMOS to other similar approaches, using both data sets (publicly available) and live data obtained by a ROV operating in real scenes. The results demonstrate that ROLAMOS is adequate for mapping of sea-floor scenarios as it provides accurate information from the seabed, which is of extreme importance for autonomous robots surveying the environment that does not rely on specialized computers.
Originality/value
The ROLAMOS is suitable for robotic applications that require an online, robust and effective technique to reconstruct the underwater environment from only visual information.
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Pouria Sarhadi, Abolfazl Ranjbar Noei and Alireza Khosravi
– The purpose of this paper is to show the application of an L1 adaptive controller to control an autonomous underwater vehicle (AUV), considering realistic perturbations.
Abstract
Purpose
The purpose of this paper is to show the application of an L1 adaptive controller to control an autonomous underwater vehicle (AUV), considering realistic perturbations.
Design/methodology/approach
In this paper, an L1 adaptive controller is proposed to control the pitch channel of an AUV, for the first time. Based on a six degree of freedom (6-DOF) nonlinear equations, an appropriate linear model considering real perturbations is derived for the pitch channel of AUV. Then L1 adaptive controller is applied on the model in the presence of the bounded disturbances and uncertainties. For this purpose, verified parameters of the REMUS AUV have been considered. Several simulations are performed in different operating conditions.
Findings
The results confirm the quality of the proposed method in various situations. Furthermore, it is shown that the L1 adaptive controller is potential to contribute in practical applications of AUVs such as other autonomous systems.
Originality/value
This is the first time that this method has been applied to an AUV.
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Yi Xia, Yonglong Li, Hongbin Zang, Yanpian Mao, Haoran Wang and Jialong Li
A switching depth controller based on a variable buoyancy system (VBS) is proposed to improve the performance of small autonomous underwater vehicles (AUVs). First, the…
Abstract
Purpose
A switching depth controller based on a variable buoyancy system (VBS) is proposed to improve the performance of small autonomous underwater vehicles (AUVs). First, the requirements of VBS for small AUVs are analyzed. Second, a modular VBS with high extensibility and easy integration is proposed based on the concepts of generality and interchangeability. Subsequently, a depth-switching controller is proposed based on the modular VBS, which combines the best features of the linear active disturbance rejection controller and the nonlinear active disturbance rejection controller.
Design/methodology/approach
The controller design and endurance of tiny AUVs are challenging because of their low environmental adaptation, limited energy resources and nonlinear dynamics. Traditional and single linear controllers cannot solve these problems efficiently. Although the VBS can improve the endurance of AUVs, the current VBS is not extensible for small AUVs in terms of the differences in individuals and operating environments.
Findings
The switching controller’s performance was examined using simulation with water flow and external disturbances, and the controller’s performance was compared in pool experiments. The results show that switching controllers have greater effectiveness, disturbance rejection capability and robustness even in the face of various disturbances.
Practical implications
A high degree of standardization and integration of VBS significantly enhances the performance of small AUVs. This will help expand the market for small AUV applications.
Originality/value
This solution improves the extensibility of the VBS, making it easier to integrate into different models of small AUVs. The device enhances the endurance and maneuverability of the small AUVs by adjusting buoyancy and center of gravity for low-power hovering and pitch angle control.
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The purpose of this paper is to review the most recent AUVSI unmanned vehicle show, with emphasis on the new robot innovations and applications on display.
Abstract
Purpose
The purpose of this paper is to review the most recent AUVSI unmanned vehicle show, with emphasis on the new robot innovations and applications on display.
Design/methodology/approach
In‐depth interviews with exhibitors of unmanned vehicles.
Findings
Unmanned vehicles are being coming more autonomous and addressing an ever‐increase range of applications in military, law enforcement, and commercial applications such as agriculture, fishing and rescue operations.
Practical implications
Customers will have to begin thinking of unmanned vehicle robots and able body helpers in all kinds of applications.
Originality/value
The paper presents a review of the latest innovations that one might have seen if they had been on the exhibition floor at the Las Vegas unmanned show.
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