Bing Wang’s research while affiliated with Wuhan University of Technology and other places

In order to solve the autonomous decision-making for ship manoeuvring in complex waters of estuarine multi-class ships routeing system, key scientific issues such as digital environment, navigation rule integration, ship manoeuvrability constraints, and collision avoidance mechanism under special waters were investigated by taking the waters from the mouth of Liu River to the North Trough as an example. The requirements of analytical rules were summarized and quantified in the digital traffic environment. The collision avoidance mechanism under the constraints of ship behavioural characteristics in such waters was explored by combining the control and process prediction methods with nonlinear ship manoeuvring characteristics. Then, a feasible heading speed finding method was established, and a ship manoeuvring autonomy decision-making method under the constraints of multifactors that can dynamically adapt to the system's residual error and the target ship's random motion was proposed. Under the preset scenarios, the ship can pass safely at 0, 38, 1 184, 1 537, 2 166, 3 678, 3 808 s by altering course 4° to starboard side, decelerating, altering course 5° to starboard and decelerating, decelerating, altering course 3° to port side accelerating, altering course 3° to starboard and decelerating, decelerating, respectively. The experiments show that the present method can safely avoid the collision in the complex environment and track the course in time.

Ship autonomous collision avoidance has attracted increasing attention in recent years. However, more attention is paid to the scenario in which the target ship keeps its course and speed. Less attention is paid to the development of a collision avoidance decision-making system under the uncertainty of the target ship's movement in a complex multi-ship encounter situation. Based on the idea of model predictive control (MPC), this paper proposes an autonomous ship collision avoidance decision-making system (CADMS) suitable for the uncertainty of ship motion. The CADMS includes four modules: collision risk analysis module, control and execution module, ship trajectory prediction module and collision avoidance decision-making model. The proposed model can be implemented in the collision avoidance decision-making system for safe navigation or it can be included in the ship autonomous navigation process. The decision-making model is achieved from a risk identification-motion prediction-ship control-scheme implementation perspective, and the dynamic and uncertainty features of the ship action (i.e., alter course or change speed) are considered in the modelling process. The real-time rolling update of ship collision avoidance decisions is realised based on the time series rolling method. Four scenarios are designed to demonstrate the collision avoidance decision-making system's performance. The results show that the proposed collision avoidance decision-making system is a reasonable and effective system for collision avoidance, particularly in multi-ship encounter situations of target ships suddenly altering course or change speed.

The intelligent navigation system of autonomous ships aims at making fully autonomous navigation decisions to replace the work of seafarers. Realizing intelligent navigation decision-making in open water is the first stage of a fully autonomous navigation system. Through real-time sampling, rapid update of the own ship's motion parameters, and traffic situation information, an open-water intelligent navigation decision-making method that can dynamically adapt to the residual error in the system and the target ship's random manoeuvre is proposed. A digital traffic environment model comprising different target types is built as the basis of navigation decision-making. An optimal feasible plans of the own ship, which will ensure all targets pass safely, is calculated using the velocity obstacle (VO) theory, and dynamic collision avoidance mechanism to construct an autonomous manoeuvring model. The simulation experiments proved that the combined results of this and previous research could realize autonomous navigation in an open water environment having multiple static and dynamic objects under the premise of satisfying the International Regulations for preventing Collisions at Sea, 1972 (COLREGs) and the good seamanship. This research will provide basic theories and methods to realize the autonomous navigation decision-making of ships in an open water environment with multiple targets.

A great number of collision accidents can be attributed to incongruous collision-avoidance actions between the give-way vessel and the stand-on vessel in a crossing or overtaking situation. If the give-way vessel does not take appropriate collision-avoidance action according to international regulations for preventing collisions at sea, the last barrier to pass safely is the appropriate and effective collision-avoidance action taken by the stand-on vessel. To find the proper autonomous collision-avoidance action of the stand-on vessel, a method is proposed that combines quantitative analysis rules of collision-avoidance with the deduction of nonlinear maneuvering motion process based on the mathematical model group, which conformity can reach 90%. This research presents a method to calculate the timing and most effective collision-avoidance actions for the stand-on vessel based on the four-stage theory of encountering vessels and the characteristics of vessel motion. The accuracy of the latest-action timing and the action amplitude for the stand-on vessel can be increased to the level of second and degree, respectively. A novel model of collision risk index is constructed by the latest time of the feasible collision-avoidance action on the precise of different course-altering amplitude. Methods to find the stand-on vessel’s proper collision-avoidance actions in the open sea are presented. The simulation indicates the proposed method for the stand-on vessel can make correct collision-avoidance decisions autonomously.

Ship collision prevention has always been a hot topic of research for navigation safety. Recently, autonomous ships have gained much attention as a means of solving collision problems by machine control with a collision-avoidance algorithm. An important question is how to determine optimal path planning for autonomous ships. This paper proposes a path-planning method of collision avoidance for multi-ship encounters that is easy to realize for autonomous ships. The ship course-control system uses fuzzy adaptive proportion-integral-derivative (PID) control to achieve real-time control of the system. The automatic course-altering process of the ship is predicted by combining the ship-motion model and PID controller. According to the COLREGs, ships should take different actions in different encounter situations. Therefore, a scene-identification model is established to identify these situations. To avoid all the TSs, the applicable course-altering range of the OS is obtained by using the improved velocity obstacle model. The optimal path of collision avoidance can be determined from an applicable course-altering range combined with a scene-identification model. Then, the path planning of collision avoidance is realized in the multi-ship environment, and the simulation results show a good effect. The method conforms to navigation practice and provides an effective method for the study of collision avoidance.