Development of Solution for Safe Ship Considering Seakeeping PERformance20190620 69578 5wklkc (original) (raw)
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Ship voyage optimization for safe and energy-efficient navigation: A dynamic programming approach
Ocean Engineering, 2018
The paper presents a 3D dynamic programming based ship voyage optimization method, aiming to select the optimal path and speed profile for a ship voyage on the basis of weather forecast maps. The optimization is performed in accordance to a minimum fuel consumption strategy taking also into account ship motions and comfort. The optimization is carried out in a discretized space-time domain: the ship voyage is parametrized as a multi-stage decision process in order to formulate a dynamic programming optimization problem. Waves and wind conditions are estimated for each route segment by weather forecasting maps then seakeeping related indexes and fuel oil consumption are computed taking into account wave-induced ship motions and added resistance. The best routing solution is thus selected by a dynamic programming algorithm developed and implemented by the authors. Results and discussion of the proposed method are presented for a merchant ship application in a test case voyage through the Northern Atlantic Ocean and compared to the constant speed great circle solution.
Development of Solution for Safe Ship Considering Seakeeping PERformance20200514 21389 1dzonuz
the International Journal on Marine Navigation and Safety of Sea Transportation, 2018
In recent years, safety of a ships has become one important issues needed to solved as soon as possible in ship navigation. Optimal weather routing is one of best solution for ensuring safe operation of a ship with a with short passage time or minimum energy to avoid a certain excessive motion. This paper introduced the development of solution for safety and optimal weather routing a ship considering seakeeping performance based on model test result. This study introduced how to apply A* algorithm based on result of the seakeeping model test for determining the optimal ship routes. Seakeeping model test of 8600 TEU container ship was carried out in Changwon National Universityʹs seakeeping basin and its RAOs at various frequencies were used to predict the RMS motion values in irregular waves. The specially modelled path‐cost function and the safety constraints were proposed for finding the optimal path of the ship. The comparison of ship performances estimated by great circle’s path and estimated optimal route during the voyage of the ship was investigated.
Applied Ocean Research, 2013
This study proposes a ship weather-routing algorithm based on the composite influence of multi-dynamic elements for determining the optimized ship routes. The three-dimensional modified isochrone (3DMI) method utilizing the recursive forward technique and floating grid system for the ship tracks is adopted. The great circle sailing (GCR) is considered as the reference route in the earth coordinate system. Illustrative optimized ship routes on the North Pacific Ocean have been determined and presented based on the realistic constraints, such as the presence of land boundaries, non-navigable sea, seaway influences, roll response as well as ship speed loss. The proposed calculation method is effective for optimizing results by adjusting the weighting factors in the objective functions. The merits of the proposed method can be summarized as: (1) the navigability of the route can be analyzed dynamically to acquire the optimal route; (2) adopting multidynamic elements as weighting factors has the benefits in energy efficiency, time-saving and minimum voyage distance; and (3) an ability to enhance speed performance and to incorporate safety concern in a dynamic environment.
Ship weather routing based on seakeeping performance
Ship weather routing is the process to efficiently avoid undesired sailing conditions, especially due to bad weather. Issues at stake are not only the ship’s and cargo’s safety, but also crew comfort. Some major factors to be considered in this process are: the minimum route distance between ports, the predicted sea state for the sailing period and the ships seakeeping performance. This paper presents a geographic infor-mation system (GIS) that determines the best sailing route, based on multicriteria raster grid analysis. The system is fed with data from a wave forecast model applied to the North Atlantic and calculates the ships per-formance for different wave significant height, period and relative wave direction to the ship’s route. Ship’s seakeeping performance in based on the roll, pitch and heave responses. A case study is presented for a voy-age between Lisbon and New York, during the month of November 2006, for a container ship sailing at 22 kts. The processing result is a geospatial cost-travelling matrix that is used to calculate the accumulated cost to sail to New York. Based on this matrix, the least cost path is then calculated and presented.
Optimal ship tracking on a navigation route between two ports: a hydrodynamics approach
Journal of Marine Science and Technology, 2012
The optimal trajectory from Calcutta port to Mumbai port is charted for a tanker transshipping from the East coast to the West coast of India during rough weather. Rough weather is simulated over Indian seas using the state-of-the-art WAM numerical wave model (WAMDI Group in J Phys Oceanogr 18:1775-1810, 1988), assimilating satellite (IRS-P4) wind fields. These simulated wave fields and two-dimensional (2D) directional wave spectrum are an absolute representation of the irregular seaway. Hence, the same for the monsoon month of August 2000 formed the input basis for this study. Loss of ship speed due to the wave field (i.e., nonlinear motion of the tanker in waves) and associated sea-keeping characteristics in the seaway are estimated (Bhattacharya in Dynamics of marine vehicles, Wiley, New York, 1978). The approach adopted in this paper is unique in that it takes into account both voluntary and involuntary speed reductions of the ship. It helps in ship tracking by the optimum route using inverse velocity as the weight function for the path in an efficient way. Dijkstra's algorithm [Numer Math 1(3):269-271, 1959] is applied in an iterative manner for determining the optimum track. The optimum track information has broad scope for use in modern shipping industry for obtaining safe and least-time routing by avoiding schedule delays with economic fuel consumption.
Multi-Objective Weather Routing of Sailboats Considering Wave Resistance
Polish Maritime Research, 2018
The article presents a method to determine the route of a sailing vessel with the aid of deterministic algorithms. The method assumes that the area in which the route is to be determined is limited and the basic input data comprise the wind vector and the speed characteristic of the vessel. Compared to previous works of the authors, the present article additionally takes into account the effect of sea waves with the resultant resistance increase on the vessel speed. This approach brings the proposed model closer to real behaviour of a sailing vessel. The result returned by the method is the sailing route, optimised based on the multi-criteria objective function. Along with the time criterion, this function also takes into account comfort of voyage and the number of performed turns. The developed method has been implemented as simulation application SaillingAssistance and experimentally verified.
Weather Route Optimization Method of Unmanned Ship Based on Continuous Dynamic Optimal Control
Sustainability, 2022
Intelligent weather route optimization method was an essential guarantee for safe and efficient navigation of ships. In traditional methods, the multi-stage decision-making method was generally used to solve route dynamic optimization problems, in which it was impossible to achieve dynamic optimal routes, due to the temporal and spatial complexity of route design. In this paper, an unmanned ship weather route optimization model was established based on a method of continuous dynamic optimal control. Marine meteorological information was analyzed. Navigation safety, energy consumption, and sailing time were integrated considered. Dual-target route evaluation function of energy consumption and sailing time was established. The problem about the multi-stage decision was transformed into that of one-step optimal control, and an improved ant colony algorithm was adopted. Simulation results showed that compared with some traditional methods, the proposed method was better performed, which...
2008
Fuel savings in ship navigation has always been a popular subject in the maritime industry as well as the world's largest Navies. Oil prices and environmental considerations drive the effort for more fuel-efficient navigation. This thesis addresses the problem of deterministic minimum fuel routing by applying optimal control theory in conjunction with state of the art hydrodynamic and weather forecasting tools. A fictitious transAtlantic route is established and the optimal combination of speed and heading is determined, so that fuel consumption is minimized while certain safety constraints are met. The safety constraints are defined as the probabilities of slamming and deck wetness, both of which are not allowed to exceed prescribed limiting TABLE OF CONTENTS
Multi-Objective Weather Routing of Sailing Vessels
Polish Maritime Research, 2017
The paper presents a multi-objective deterministic method of weather routing for sailing vessels. Depending on a particular purpose of sailboat weather routing, the presented method makes it possible to customize the criteria and constraints so as to fit a particular user’s needs. Apart from a typical shortest time criterion, safety and comfort can also be taken into account. Additionally, the method supports dynamic weather data: in its present version short-term, mid-term and long-term term weather forecasts are used during optimization process. In the paper the multi-objective optimization problem is first defined and analysed. Following this, the proposed method solving this problem is described in detail. The method has been implemented as an online SailAssistance application. Some representative examples solutions are presented, emphasizing the effects of applying different criteria or different values of customized parameters.