Local Route Planning for Collision Avoidance of Maritime Autonomous Surface Ships in Compliance with COLREGs Rules

A maritime autonomous surface ship (MASS) ensures safety and effectiveness during navigation using its ability to prevent collisions with a nearby target ship (TS). This avoids the loss of human life and property. Therefore, collision avoidance of MASSs has been actively researched recently. However, previous studies did not consider all factors crucial to collision avoidance in compliance with the International Regulations for Preventing Collisions at Sea (COLREGs) Rules 5, 7, 8, and 13–17. In this study, a local route-planning algorithm that takes collision-avoidance actions in compliance with COLREGs Rules using a fuzzy inference system based on near-collision (FIS-NC), ship domain (SD), and velocity obstacle (VO) is proposed. FIS-NC is used to infer the collision risk index (CRI) and determine the time point for collision avoidance. Following this, I extended the VO using the SD to secure the minimum safe distance between the MASS and the TS when they pass each other. Unlike previous methods, the proposed algorithm can be used to perform safe and efficient navigation in terms of near-collision accidents, inferred CRI, and deviation from the course angle route by taking collision-avoidance actions in compliance with COLREGs Rules 5, 7, 8, and 13–17.

VECTOR FIELD GUIDANCE LAW FOR CURVED PATH FOLLOWING OF AN UNDERACTUATED AUTONOMOUS SHIP MODEL

A vector field guidance law and control system for curved path following of an underactuated surface ship model is presented in this paper. In order to obtain the curved path, continuous derivatives piecewise cubic Hermite interpolation is applied for path generation based on the predefined waypoints. A heading autopilot controller is designed based on 2nd order Nomoto’s model and its stability is guaranteed by the Diagram of Vyshnegradsky method. The parameters of Nomoto model are estimated using least square support vector machine based on the manoeuvring tests. The vector field guidance law is applied for both straight and curved path-following control of an underactuated surface ship model. In order to demonstrate the performance, the classical guidance law based on line-of-sight, is adopted for comparison. The results show that the vector field method is capable to solve the guidance problem of underactuated surface ships.

AN OPTIMIZED ENERGY-EFFICIENT PATH FOLLOWING ALGORITHM FOR UNDERACTUATED MARINE SURFACE SHIP MODEL

An optimized path following guidance law is proposed for path-following of an underactuated surface ship. The main purpose of the proposed guidance law is to make a marine vessel travel with more energy efficiency. A combined feedback and feedforward controller is used for the heading control. The feedforward term is designed based on the well-known Nomoto model, whose parameters are estimated using least-square support vector regression. In order to achieve optimal operation of a marine vessel, a global optimization algorithm is employed to search the regularization factors, which are the trade-off between the total cross-track errors and total control energy. The simulation studies are carried out to demonstrate the performance of the proposed guidance law. The proposed method is an effective and practical guidance law and provide an optimal option for marine navigator.

Collision Risk Assessment Support System for MASS RO and VTSO Support in Multi-Ship Environment of Vessel Traffic Service Area

The discussions by the International Maritime Organization for the introduction of a maritime autonomous surface ship (MASS) began in earnest. At the 27th ENAV meeting, the International Association of Marine Aids to Navigation and Lighthouse Authorities proposed the “sharing of a common operating picture for situational awareness of the waterway within vessel traffic service (VTS) environment” when developing a system to support MASS operation. Marine accidents caused by collisions on waterways still account for a high percentage of ship accidents that occur at sea, and many studies have investigated the risk of collision between ships. Collision risk assessment was primarily conducted in ship domain-based safety areas. This study evaluates the collision risk using the ship domain derived by the VTS operator (VTSO) and proposes a real-time collision risk assessment support system to improve the situational awareness of VTSOs and MASS remote operators (MASS ROs) regarding near-collision situations occurring in local waters. To evaluate the validity of the proposed system, a risk analysis was performed on near-collision scenarios at Busan Port. The results show that the distance to the closest point of approach (CPA), time to the CPA, and inter-ship distance converged within 0.5 nautical miles, 10 min, and 3 nautical miles, respectively.

The peculiarities of the unmanned ships operaiting

Материал статьи отражает развитие тенденции внедрения в практику судоходной индустрии судов без экипажа на борту. Оснащение современных судов интегрированными системами контроля и управления оборудованием позволяет управлять судовой энергетической установкой без постоянного присутствия членов машинной команды. Многие вопросы, связанные с проведением мероприятий по обслуживанию механизмов и устройств решаются в период межрейсовых стоянок специальным персоналом. Это приближает деятельность экипажа к условиям работы операторов технологических объектов и стимулирует появление транспортных средств с малоэкипажным составом или вообще без экипажа. Морские автономные надводные суда (МАНС), как они классифицируются в международной практике, уже реальность и необходимо обоснованно подходить к системе управления по мере увеличения количества таких объектов и их технического совершенствования. Основное внимание в статье уделяется роли и месте расположения судовых специалистов, без которых практически невозможно технически грамотно эксплуатировать судовую энергетическую установку, независимо от ее типа и особенностей конструктивного исполнения. Приводятся примеры уже работающих МАНС. Авторы рассматривают наиболее реальные варианты формирования системы искусственного интеллекта и наделения ее функциями контроля состояния и управления элементами судовой энергетики. The article material reflects the trend development implementing into the shipping industry practice the vessels without a crew on board. Equipping modern ships with integrated monitoring and control systems allows the ship's power plant to be operated without the constant presence of the engine crew members. Many issues related to the maintenance of mechanisms and devices are resolved during inter-trip stops by special personnel. This brings the crew activities closer to the working conditions of the technological facilities operators and stimulates the appearance of means of transport with a small crew or no crew at all. Maritime Autonomous Surface Ship (MASS), as they are classified in international practice, are already a reality and it is necessary to reasonably approach the control system as the number of such objects increases and their technical improvement. The main attention in the article is paid to the role and location of ship specialists, without whom it is practically impossible to operate a ship power plant in technically competent manner, regardless of its type and design features. Examples of already operating MASS are given. The authors consider the most realistic options for an artificial intelligence system formation and endowing it with the functions of monitoring the state and control of the elements of ship power engineering.