Research On Dynamic Positioning Of Submarine Cable Workboat Based Fuzzy Control

A 2,000 ton submarine cable workboat is mainly responsible for the laying, burying and maintenance of submarine optical cable and small submarine cables / optical composite cables. Dynamic positioning system has advantages such as excellent track control, stability control and advanced automatic track control, which could meet the requirements of accuracy and stability on the submarine cable construction and maintenance in order to ensure the safety and reliability of underwater operation. Therefore, it is necessary to install a dynamic positioning system on this type of workboat. Based on this type of workboat, this paper designed a dynamic positioning control system to enable its propulsion system to generate necessary vertical and lateral thrust and turning moment to resist external interference in order to finish submarine cable construction and maintenance work in the specified area.First of all, the paper proposed the concept of integrated dynamic positioning centered on the underwater operating system, and put forward a configuration program for the dynamic positioning system of 2,000 ton submarine cable workboat.Then, this paper analyzed the development trends that classical control theory, modern control theory and intelligent control theory apply on the dynamic positioning control technology. It also gave a full consideration to the advantages of fuzzy control, such as independent of accurate mathematical model, anti-interference ability, fast response and robustness. Based on a 2,000 ton submarine cable workboat, fuzzy control has been applied as the dynamic positioning system controller for this type of workboat.Finally, the fuzzy control theory has been applied to design a dynamic positioning control system for this type of workboat, and this controller was placed in wind speed 10m / s, currents 1.5m / s under interference conditions for sea state simulation. The simulation results showed that the design can meet the required control precision that its operation needs. To make up for the blind area that the fuzzy controller caused near the equilibrium, this paper introduced PID control, and united it with and fuzzy controller to constitute the F-PID composite controller. A dynamic positioning system was designed for a 2,000 ton submarine cable workboat, and was placed under the disturbance of the above-mentioned conditions for sea state simulation. The simulation results showed that the design can meet the operating precision that its operation needs.By comparing the above two results of controller simulation, F-PID composite controller has a higher steady-state accuracy than a single fuzzy controller.