Crane operations are very important in aquaculture industry and used in almost all aspects of operations that involve service vessels. At the same time, crane operations are associated with a high level of risk for human operators. There is also the risk of damage to the fish farms, which can negatively affect fish welfare and lead to financial loss through fish escaping. In this internal pre-project, SINTEF Ocean AS investigated if and how crane operations in aquaculture can be automated to reduce the risk factors involved, as how this could potentially improve fish welfare.
Cranes used in aquaculture are often modified truck cranes with hydraulic control, as hydraulic cranes are often more robust and have a higher lift capacity than electric cranes. The cranes generally have a very low degree of automation, with few sensors and automatic systems involved in the crane control. Ships and crane systems are often completely disconnected from each other.
This project has shown that control of cranes in aquaculture can improve in many aspects: Improved load control through load cells, automatic compensation tools, dynamic positioning of the crane tip or load, crane load position or velocity control etc. When crane control in aquaculture reaches this level of control, in can be improved further by including autonomous functions such as obstacle avoidance, path following etc., or remote control from a central operation hub.
This pre-project ran from May 2020 till the end of 2021, and is in its final stage. A part of this pre-project was to create a mathematical model of the crane at M/S Torra and investigate which control algorithms for similar cranes that are available. The findings in this project can work as a foundation for future work on cranes in aquaculture. The next steps could be to control the crane via PLS/control unit, install sensors necessary to monitor the crane operations, and eventually implement remote control of the crane as a first step towards autonomy.
