An overview of disruptive technologies for aquaculture

This paper aims to provide an overview of the capabilities of unmanned systems to monitor and manage aquaculture farms that support precision aquaculture using the Internet of Things. The locations of aquaculture farms are diverse, which is a big challenge on accessibility. For offshore fish cages, there is a difficulty and risk in the continuous monitoring considering the presence of waves, water currents, and other underwater environmental factors. Aquaculture farm management and surveillance operations require collecting data on water quality, water pollutants, water temperature, fish behavior, and current/wave velocity, which requires tremendous labor cost, and effort. Unmanned vehicle technologies provide greater efficiency and accuracy to execute these functions. They are even capable of cage detection and illegal fishing surveillance when equipped with sensors and other technologies. Additionally, to provide a more large-scale scope, this document explores the capacity of unmanned vehicles as a communication gateway to facilitate offshore cages equipped with robust, low-cost sensors capable of underwater and in-air wireless connectivity. The capabilities of existing commercial systems, the Internet of Things, and artificial intelligence combined with drones are also presented to provide a precise aquaculture framework.

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A Review of Unmanned System Technologies with Its Application to Aquaculture Farm Monitoring and Management

Towards a Digital Twin for Thermal Processes: Control-centric approach

Hazard identification methods are important tools to verify that the system is able to operate according to specifications under different operating conditions. Unfortunately, many of the tradition...

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Combining system-theoretic process analysis and availability assessment: A subsea case study:

Complex industrial automation systems and processes, such as chemical processes, manufacturing systems, wireless network systems, power and energy systems, smart grids and so forth, have greatly contributed to our daily life [...]

https://www.mdpi.com/2227-9717/9/4/664/pdf

Special Issue on “Advances in Condition Monitoring, Optimization and Control for Complex Industrial Processes”

Aquaculture net cage inspection and maintenance is a central issue in fish farming. Inspection using autonomous underwater vehicles is a promising solution. This paper proposes laser-camera triangulation for pose estimation to enable autonomous net following for an autonomous vehicle. The laser triangulation 3D data is experimentally compared to a doppler velocity log (DVL) in an active fish farm. We show that our system is comparable in performance to a DVL for distance and angular pose measurements. Laser triangulation is promising as a short distance ranging sensor for autonomous vehicles at a low cost compared to acoustic sensors.

https://www.mdpi.com/2077-1312/9/1/79/pdf

ROV Navigation in a Fish Cage with Laser-Camera Triangulation

Biofouling is a challenge for finfish farming as it can impact cage stability and fish health. Amongst others, current strategies against biofouling rely heavily on removal of biofouling using in-situ pressure cleaning of nets. The cleaning waste is released into the water where it can impact the health of the cultured fish. Grooming, the regular cleaning of nets to prevent biofouling communities from establishing, is one novel strategy that is currently explored using tethered underwater robots. In addition, remotely operated vehicles (ROVs) are used for inspection of the net to ensure its integrity and prevent fish escapes, while stationary sensors at the farm barge are employed to extrapolate on environmental conditions in the net pens. In this paper, the requirements for a permanently resident, autonomous and tetherless subsea robot for cleaning and inspection are proposed. As such, the robot aims to combine several application areas and offer a solution to the biofouling challenge while at the same time improving safeguarding of net integrity and monitoring of environmental conditions directly in the pen. Using the SEATONOMY method from an operational viewpoint, the robot's individual operations are analysed. This included i) Environmental condition monitoring, ii) Net and biofouling inspection, iii) Growth prevention and iv) Docking. As a result, the specifications and requirements for the development of a novel robotic system that is able to simultaneously and autonomously perform inspection, growth prevention and monitoring in fish cages were derived. The paper proposes the development of a new technology and biofouling management strategy that will contribute to increase the efficiency and production demands in the aquaculture industry.

Analysis of a novel autonomous underwater robot for biofouling prevention and inspection in fish farms

As subsea production of oil and gas reaches deeper and more remote waters, the need for more compact separation equipment arises. The gas hquid cylindrical cyclone (GLCC) is a widely used separation device in topside facihties, but has yet to reach the same popularity subsea. The GLCC separates gas and liquid by inducing a swirl on the multiphase flow. Because of its small size, the GLCC is sensitive to flow variations which may reduce separation performance. The performance of the GLCC can be improved by control. In this paper we consider a nonlinear dynamic model of a GLCC containing unmeasured variables and states. We present an adaptive feedback linearizing controfler and prove that the origin of the gas pressure and liquid level error systems are locally asymptotically stable in the sense of Lyapunov on a specified domain. The model and controller are implemented in Simulink and simulations show that the controfler works very wefl, even with uncertainties in assumed known parameters, and measurement noise.

/pdf/adaptive-feedback-linearizing-control-of-a-gas-liquid-4r4d1xjfuy.pdf

Sveinung Johan Ohrem

Papers

ROV Navigation in a Fish Cage with Laser-Camera Triangulation

Analysis of a novel autonomous underwater robot for biofouling prevention and inspection in fish farms

Adaptive feedback linearizing control of a gas liquid cylindrical cyclone

Application of systems-theoretic process analysis to a subsea gas compression system

Modeling and nonlinear model predictive control of a subsea pump station