Automatic Optimal Control of a Vessel with Redundant Structure of Executive Devices

Abstract

The article considers the issues of automatic control of the vessel movement with a redundant control structure. Redundant structures are now widely used on all vessels with a dynamic positioning system to improve control efficiency (accuracy, maneuverability, reduce energy consumption and emissions), reliability and environmental safety. A brief review of the literature on the use of redundant structures to improve control efficiency is made. In open sources, the authors have not found solutions that improve the efficiency of the control by using redundant structures of actuators. Therefore, it was concluded that the development of such systems is relevant. Several schemes for splitting control into executive devices of a redundant structure, including an optimal splitting scheme, are considered. A comparative analysis of the considered splitting schemes with the optimal one is carried out. Comparative analysis showed that the use of optimal control of the redundant structure of actuators allows increasing the accuracy of dynamic positioning by (20-40)%, depending on the direction of the created control, as well as reducing fuel consumption by (30-100)%, which determines its advantages over known solutions. The mathematical and software support for an automatic optimal control system with redundant control has been developed. The operability and efficiency of the mathematical and software support were tested in a closed circuit with a control object in the MATLAB environment. The conducted experiments confirmed the operability and efficiency of the developed method, algorithms and software and allow to recommend them for practical use in the development of vessel control systems with redundant control structures.

Using redundant control to optimize control torque

“…The obtained result of increasing the control moment, speed of rotation and reducing the time for turning the vessel is explained by the optimization of the control moment in the redundant structure [9]. This is achieved by: using an on-board calculator; solving, at each step of the on-board computer, an optimization problem with a non-linear objective function, linear and non-linear control constraints; transfer of optimal controls to the automation of executive devices for testing.…”