A method of the guaranteeing optimization for the dynamics of ship moving in wave

Abstract

With the further development of the world economy, the corresponding transportation infrastructure has also brought about many problems, which, foremost, are associated with the traffic safety of vehicles. In particular, the issue of ship traffic safety has become even more important as maritime traffic continues to grow. The main attention in this article is given to the development of methods and the design of computational algorithms for the synthesis of multipurpose control in marine autopilots, the main purpose of which is to counteract the effects of sea waves in order to preserve the movement at a given course. Currently, various approaches are used for the design of autopilots, a large number of scientific papers have been published, but the problem of the synthesis of control laws for these systems has not been exhaustively resolved. First of all, this is due to their multipurpose mission, which determines the need for work in various driving regimes with conflicting requirements for the quality of dynamic processes. In this paper, we propose a new practically oriented method for the synthesis of control laws for autopilots, which is based on feedbacks with a multipurpose structure. However, these works of optimization approach had assumed that the initial data includes a known frequency spectrum of sea waves, the knowledge about which comes in the course of identification, realized in the system of adaptive autopilot reconfiguration. Naturally, such a consideration of the actual conditions of navigation significantly improves the quality of management processes. But adaptive reconfiguration, for lots of reasons, cannot always be applied in practice. For example, it may not allow enough time for the system’s operating conditions. To this end we have developed a simple constructive method for calculating the transfer function for a dynamic filter as part of the heading control law implemented by a marine autopilot. This method is based on the ideology H∞-optimization, which makes it possible to ensure a guaranteed quality of filtration when moving in sea waves. Unlike other widely used approaches, the indicated purpose will be achieved by using the specialized multipurpose structure of the control law. The approach has lot of advantages in comparison with alternative options, namely flexibility configuration in real conditions of navigation. The proposed approach can be expanded by applying it to control marine unmanned objects or floating offshore structures. Refs 11. Fig. 1.