Smart offshore heavy lift operations

Autonomous vessels have developed into a popular research area in both industry and academia. The application of autonomy in offshore and coastal engineering could offer a safe and efficient solution to offshore transportation and operation. However, the state of the art in research has focused on waterborne transportation. Very limited research activity has been in the field of autonomous heavy lift operations. Offshore heavy lift vessels are construction vessels with large scale hydraulic cranes. One challenge to achieve autonomous offshore heavy lifting is to make smart control systems for the subsystems involved in offshore construction work, and to integrate the systems in a coordinated framework.
In this thesis, an smart control system consisting of three subsystems is proposed for safe smart offshore heavy lifting, which aims to replace or assist human operators during offshore heavy lift construction. To develop this smart system, a robust switching Dynamic Positioning (DP) controller to stabilize the position of the vessel, a nonlinear model-based mode detection system to detect the mode switching, and a backstepping crane tension controller to stabilize the load are designed.