ECDIS steering algorithm for vessel autopilot

Offshore Systems Ltd. (OSL) produces an ECDIS (electronic chart display and information system), which is called the Electronic Chart Precise Integrated Navigation System (ECPINS). The objective of the ECPINS research is to incorporate the essentials of marine navigation into a single bridge display that automates marine navigation, thereby reducing cost and increasing safety. Currently OSL has incorporated electronic charts, positioning algorithms, route planning, and radar overlay into its ECDIS. The positioning algorithms implement Kalman filters to track radar targets and to estimate the vessel's position. This paper presents a proposed steering algorithm based on optimal control concepts for the vessel's autopilot. The performance of the steering algorithm for the vessel's autopilot is evaluated by processing synthetic data. Desired route and vessel steering trajectories are presented and the performance is evaluated. From the results obtained and analyses conducted, it was found that this preliminary autopilot design provided a good basis for a final steering algorithm.