COLREG rule-based autonomous ship meeting collision avoidance method

Abstract

The invention discloses an autonomous ship meeting collision avoidance method based on a COLREG rule, and relates to the field of autonomous ship control, and the method comprises the steps: obtaining the real-time navigation parameters of a ship and other ships in a detection range; based on a COLREG rule, dividing avoidance responsibilities of the ship and other ships; according to the real-time navigation parameters of the ship and other ships and the avoidance responsibility of the ship and other ships, the repulsive force potential energy of other ships to the ship when the ship sails along the target route is determined; and according to the gravitational potential energy of the navigation target point of the target route to the ship and the repulsive potential energy of all other ships to the ship, comprehensive potential energy borne by the ship is obtained through calculation, the target navigational speed and the target rudder angle are determined in combination with the COLREG rule, and the ship is controlled to carry out collision-prevention navigation. According to the method, real-time monitoring is carried out in the whole meeting process, automatic collision avoidance is completed, the collision avoidance problem under all meeting situations can be solved, and the safety and stability of the autonomous ship are effectively improved.

Description

Technical Field

[0001] This application relates to the field of autonomous ship control, and in particular to a method for avoiding collisions when autonomous ships meet based on the COLREG rules. Background Art

[0002] In recent years, with the continuous growth of global trade and the booming development of the maritime transportation industry, the demand for autonomous ships has been increasing and developing rapidly. During the navigation of autonomous ships, they not only need to face complex marine environments but also encounter other ships. Therefore, accurate collision avoidance during encounters is of great significance for the safety and stability of autonomous ships.

[0003] Traditional ship collision avoidance methods mainly rely on the experience and judgment of crew members. However, in today's complex and ever-changing marine environment with an increasing number of ships, autonomous ships relying solely on the artificial experience of crew members often cannot make timely decisions to cope with changing encounter situations and can no longer meet the requirements for the safe navigation of autonomous ships. Summary of the Invention

[0004] In view of the above problems and technical requirements, this application proposes a method for avoiding collisions when autonomous ships meet based on the COLREG rules. The technical solution of this application is as follows:

[0005] A method for avoiding collisions when autonomous ships meet based on the COLREG rules includes the following steps:

[0006] Obtain the real-time navigation parameters of the own ship and each other ship within the detection range;

[0007] Based on the COLREG rules, divide the collision avoidance responsibilities of the own ship and the other ship m k according to the real-time navigation parameters of the own ship and any other ship m within the detection range; k

[0008] Determine the repulsive potential energy of the other ship m k on the own ship when the own ship sails along the target route according to the real-time navigation parameters of the own ship and the other ship m k and the collision avoidance responsibility of the own ship and the other ship m; k wherein, the greater the influence of the other ship m k on the navigation state of the own ship, the greater the value of the repulsive potential energy;

[0009] Calculate the comprehensive potential energy U received by the own ship according to the gravitational potential energy of the own ship with respect to the navigation target point of the target route and the repulsive potential energy of all other ships on the own ship, U = U a + U r ; where ξ is the gravitational potential energy coefficient, d qpis the distance between the navigation target point and the ship itself, I is the total number of other ships within the detection range of the ship itself, and the integer parameter I ≥ 1;

[0010] Determine the target speed and target rudder angle of the ship in the current encounter situation according to the comprehensive potential energy U and the COLREG rules, and control the collision avoidance navigation of the ship according to the target speed and target rudder angle.

[0011] Its further technical solution is to determine any other ship m k The repulsive potential energy on the ship itself including:

[0012] Determine the distance d between the ship itself and any other ship m k ; qk ;

[0013] When d qk > d rep it is determined that the other ship m k is within the safe navigation range of the ship itself, and determine the repulsive potential energy of the other ship m k on the ship itself

[0014] When d qk ≤ d emg it is determined that the other ship m k is within the emergency avoidance range of the ship itself, and determine the repulsive potential energy of the other ship m k on the ship itself

[0015] When d emg < d qk ≤ d rep it is determined that the other ship m k is within the conventional avoidance range of the ship itself. According to the real-time navigation parameters of the ship itself and the other ship m k , the navigation state of the other ship m k and the avoidance responsibilities of the ship itself and the other ship m k determine the repulsive potential energy of the other ship m k on the ship itself

[0016] Among them, d rep is the first distance threshold, d emg is the second distance threshold, and η 3 is the emergency repulsive potential energy coefficient.

[0017] Its further technical solution is to determine any other ship m k The repulsive potential energy on the ship itself including:

[0018] When it is determined that the navigation state of the other ship m k is abnormal, determine the other ship m kRepulsive potential energy of this ship η 2 is the abnormal ship repulsive potential energy coefficient;

[0019] When it is determined that the navigation state of the other ship m k is normal, according to the navigation motion parameters included in the real-time navigation parameters of this ship and the other ship m k and the avoidance responsibilities of this ship and the other ship m k determine the repulsive potential energy of the other ship m k on this ship

[0020] Its further technical solution is that, according to the navigation motion parameters of this ship and the other ship m k and the avoidance responsibilities of this ship and the other ship m k determine the repulsive potential energy of the other ship m k on this ship including:

[0021] Determine the collision risk index I k according to the navigation motion parameters of this ship and the other ship m Re ;

[0022] When the collision risk index I Re indicates that there is no collision risk between this ship and the other ship m k determine

[0023] When the collision risk index I Re indicates that there is a collision risk between this ship and the other ship m k determine the repulsive potential energy of the other ship m k on this ship according to the avoidance responsibilities of this ship and the other ship m k

[0024] Its further technical solution is that, according to the avoidance responsibilities of this ship and the other ship m k determine the repulsive potential energy of the other ship m k on this ship including:

[0025] When the avoidance responsibility of this ship is the give-way vessel, determine the repulsive potential energy of the other ship m k on this ship η 1 is the give-way vessel repulsive potential energy coefficient;

[0026] When the avoidance responsibility of this ship is the stand-on vessel, determine the repulsive potential energy of the other ship m k on this ship

[0027] Its further technical solution is that the give-way vessel repulsive potential energy coefficient η 1 ​and the abnormal ship repulsion potential energy coefficient η 2 is much smaller than the emergency repulsion potential energy coefficient η 3 .

[0028] Its further technical solution is that the navigation motion parameters of each ship include position, course, and speed. According to the navigation motion parameters of this ship and ship m k to determine the collision risk index I Re including:

[0029] According to the respective positions of this ship and ship m k to determine the distance d k between this ship and ship m qk , according to the respective speeds of this ship and ship m k to determine the relative speed of this ship and ship m k , according to the respective courses of this ship and ship m k to determine the course angle θ k between this ship and ship m

[0030] According to the distance d k between this ship and ship m qk , relative speed, and course angle θ to determine the collision risk index I k of this ship and ship m Re .

[0031] Its further technical solution is that the collision risk index I Re =V x d qk cosθ + V y d qk sinθ, where V x is the component of the relative speed of this ship and ship m k on the x-axis of the geodetic coordinate system, V y is the component of the relative speed of this ship and ship m k on the y-axis of the geodetic coordinate system, θ is the course angle between this ship and ship m k ; when I Re >0, it is determined that there is a collision risk between this ship and ship m k ; when I Re ≤0, it is determined that there is no collision risk between this ship and ship m k .

[0032] Its further technical solution is that the real-time navigation parameters of the other ship include the navigation motion parameters of the other ship and the obstacle avoidance performance status. Determining that the navigation state of ship m k is abnormal includes:

[0033] When the obstacle avoidance performance status in the real-time navigation parameters of ship m k indicates ship m kWhen the obstacle avoidance performance state is abnormal, or when the navigation stability of vessel m is detected to be abnormal based on the navigation motion parameters in the real-time navigation parameters of vessel m k , determine that the navigation state of vessel m k is abnormal k .

[0034] A further technical solution thereof is that determining the target speed and target rudder angle of the own ship in the current encounter situation according to the comprehensive potential energy U in combination with the COLREG rules includes:

[0035] Derive the comprehensive repulsive force F from the comprehensive potential energy U, and determine the candidate speed and candidate rudder angle of the own ship in the current encounter situation according to the magnitude and direction of the comprehensive repulsive force F;

[0036] Screen out the candidate speed and rudder angle that comply with the COLREG rules as the target speed and target rudder angle of the own ship in the current encounter situation.

[0037] The beneficial technical effects of this application are:

[0038] An autonomous ship encounter collision avoidance method based on the COLREG rules proposed in this application monitors the comprehensive potential energy received by the own ship in real time throughout the entire process from the start to the end of the encounter process between the autonomous ship and other ships, and continuously adjusts the course and speed of the own ship according to the comprehensive potential energy. It realizes the full-process automatic collision avoidance of autonomous ships in all encounter situations. Compared with the traditional method relying on manual experience, it effectively improves the accuracy and timeliness of the collision avoidance process, and ensures the safe and stable navigation of autonomous ships.

[0039] Using the potential energy method to comprehensively consider the attracting effect of the navigation target point on the own ship and the repulsive effect of all other ships on the own ship ensures that the own ship can effectively avoid other ships while continuously moving forward towards the navigation target point, can give the most suitable collision avoidance decision for the current encounter situation and can solve the collision avoidance problem in the complex scenario of multi-ship encounters. At the same time, when using the target course and target speed obtained from the comprehensive potential energy for collision avoidance, it complies with the provisions of the COLREG rules, ensuring the reliability of the final obtained target course and target speed results, further improving the safety of autonomous ships, reducing the probability of autonomous ship collision accidents, and thus promoting the smooth progress of maritime traffic safety. Description of the Drawings

[0040] Figure 1 is the block diagram of the navigation system of the autonomous ship.

[0041] Figure 2 is the flow chart of the autonomous ship encounter collision avoidance method.

[0042] Figure 3 is the encounter situation judgment diagram. Detailed Embodiments

[0043] The following further describes the specific implementation manners of the present application in conjunction with the accompanying drawings.

[0044] Utilize Figure 1 the navigation system of the autonomous ship shown in the figure to execute a method for meeting and collision avoidance of autonomous ships based on the COLREG rules proposed by the present application.

[0045] The navigation system includes a perception module, an autonomous decision-making module, and a control module. The perception module obtains the real-time navigation parameters, ship length, ship draft, side light signals, and other attribute information of the autonomous ship and other ships within its detection range, as well as the marine environment information of the sea area where the autonomous ship is located, through the radar system, automatic identification system, and video monitoring equipment installed on the autonomous ship. The autonomous decision-making module automatically divides the collision avoidance responsibilities between the own ship and other ships by using the information obtained by the perception module, and gives a collision avoidance decision to successfully complete the current meeting situation. The control module generates control instructions according to the collision avoidance decision given by the autonomous decision-making module and controls the autonomous ship to avoid collision or gives auxiliary navigation suggestions that can solve the current meeting situation.

[0046] Based on the navigation system of the autonomous ship, a method for meeting and collision avoidance of autonomous ships based on the COLREG rules proposed by the present application, please refer to Figure 2 the flowchart shown in the figure, and the specific steps are as follows:

[0047] Step 1, use the perception module of the navigation system to obtain the real-time navigation parameters of the own ship and each other ship within the detection range. Based on the COLREG rules, divide the collision avoidance responsibilities between the own ship and other ship m k according to the real-time navigation parameters of the own ship and any other ship m k within the detection range.

[0048] The COLREG rules are the International Convention on the Rules of the Road for Preventing Collisions at Sea, which are the key norms for global maritime traffic management. Its core purpose is to reduce maritime collision accidents and fully ensure the safety of ship navigation. The rules have made detailed regulations on aspects such as ship lights, signals, navigation marks, and collision avoidance rules, so as to ensure that ships can take correct actions in the complex and changeable marine environment. At the current stage, the COLREG rules provide a unified and clear standard for the meeting situations of global maritime ships. Therefore, the method for meeting and collision avoidance of autonomous ships in the present application is based on these rules.

[0049] When an autonomous ship is sailing at sea, it obtains the real-time navigation parameters of the own ship and each other ship within the detection range in real time, and determines the current meeting situation according to the position, speed, and heading in the real-time navigation parameters.

[0050] According to the regulations on meeting situations in the COLREG rules, please refer to Figure 3, in the figure, OS represents the own ship, and COG represents the course over ground of the ship. Taking the course of the own ship as the dividing line, according to the relative position angle of the other ship m k with respect to the own ship, it is divided into 5 regions. In the figure, regions a and b indicate that the position of the other ship m k is on the forward direction of the own ship. According to the relationship between the course of the other ship m k and the course of the own ship, it can be divided into a head-on or overtaking situation. When the position of the other ship m k and the own ship is in region a, a left head-on or left overtaking situation is formed. When the position of the other ship m k and the own ship is in region b, a right head-on or right overtaking situation is formed. In the figure, region c indicates that the other ship m k is on the starboard side of the own ship. Whether it is a crossing situation can be determined according to whether the courses of the two ships cross. In the figure, region d indicates that the other ship m k is within the range of 22.5° behind the port and starboard beam of the own ship. If the course of the other ship m k is similar to that of the own ship and its speed is greater than that of the own ship, an overtaking situation is formed with the own ship, and the own ship is the overtaken ship. In the figure, region e indicates that the other ship m k is on the port side of the own ship. Whether a crossing situation is formed can be determined according to whether the courses of the two ships cross.

[0051] After determining the current meeting situation, the relevant rules and regulations regarding ship meetings in the COLREG rules can be referred to, and the avoidance responsibilities of the own ship and the other ship m k are divided according to the rules. Among them, in a crossing situation, the stand-on ship and the give-way ship need to be divided. In an overtaking situation, the own ship is the give-way ship. In a situation of being overtaken, the own ship is the stand-on ship. In a head-on situation, both ships are give-way ships.

[0052] Step 2, determine the repulsive potential energy of the other ship m k on the own ship according to the real-time navigation parameters of the own ship and the other ship m k and the avoidance responsibilities of the own ship and the other ship m k when the own ship sails along the target route Among them, the greater the influence of the other ship m k on the navigation state of the own ship, the greater the value of the repulsive potential energy is.

[0053] When an autonomous ship sails along a target route at sea, it needs to continuously move forward towards the target navigation point in the target route. During this process, it will be affected by other ships. To avoid collisions with other ships, the own ship needs to move away from other ships. Therefore, this application realizes the effect of moving away from other ships by analyzing the repulsive potential energy of other ships on the own ship.

[0054] In one embodiment, determine the repulsive potential energy of any other ship m k on the own ship The specific method is as follows:

[0055] Based on the real-time navigation parameters of this ship and other ship m k to determine the distance d between this ship and any other ship m k ; qk ;

[0056] When d qk > d rep it is determined that other ship m k is within the safe navigation range of this ship, and it is determined that other ship m k has a repulsive potential energy on this ship Other ship m within the safe navigation range of this ship k does not affect the navigation state of this ship;

[0057] When d qk ≤ d emg it is determined that other ship m k is within the emergency avoidance range of this ship, and it is determined that other ship m k has a repulsive potential energy on this ship η 3 is the emergency repulsive potential energy coefficient; the closer other ship m within the emergency avoidance range of this ship is to this ship, the greater the impact on the navigation state of this ship; k ;

[0058] When d emg < d qk ≤ d rep it is determined that other ship m k is within the conventional avoidance range of this ship. According to the real-time navigation parameters of this ship and other ship m k , the navigation state of other ship m k , and the avoidance responsibilities of this ship and other ship m k to determine the repulsive potential energy of other ship m k on this ship

[0059] wherein, d rep is the first distance threshold, d emg is the second distance threshold, d emg < d rep . Each distance threshold is comprehensively determined based on factors such as the maneuvering performance of the ship, the ship speed, and the current ocean environment. When the distance between the two ships is less than d emg , it indicates that the encounter situation between the two ships is very urgent, and emergency collision avoidance measures must be immediately initiated for avoidance. The specific values of the first distance threshold d rep and the second distance threshold d emg can be custom-set according to actual experience or simulation calculations.

[0060] Specifically, when d emg < dqk ≤ d rep When it is determined that any other ship m k has a repulsive potential energy with respect to the own ship The method is as follows:

[0061] First, judge the navigation state of the other ship m k When it is determined that the navigation state of the other ship m k is abnormal, determine the repulsive potential energy of the other ship m k with respect to the own ship η 2 is the abnormal ship repulsive potential energy coefficient.

[0062] In one embodiment, the real-time navigation parameters of the other ship include the navigation motion parameters of the other ship and the obstacle avoidance performance state. Determining that the navigation state of the other ship m k is abnormal includes:

[0063] When the obstacle avoidance performance state in the real-time navigation parameters of the other ship m k indicates that the obstacle avoidance performance state of the other ship m k is abnormal, or when it is detected from the navigation motion parameters in the real-time navigation parameters of the other ship m k that the navigation stability of the other ship m k is abnormal, determine that the navigation state of the other ship m k is abnormal.

[0064] Among them, the obstacle avoidance performance parameter is used to characterize the operation state of the other ship m k When the other ship m k is a restricted ship, an out-of-control ship or a fishing boat engaged in trawling operations, the other ship m k is unable to avoid obstacles, and its obstacle avoidance performance state is abnormal. On the other hand, the navigation stability of the other ship m k is judged by detecting the navigation motion parameters of the other ship m k The navigation stability of the other ship m k is determined by detecting the changes in the course and trajectory of the other ship m k over a period of time. When the course and trajectory of the other ship m k change abnormally, it is determined that the navigation state of the other ship m k is abnormal. The specific abnormal detection method can use the methods of the existing technology, which will not be elaborated in this application.

[0065] When it is determined that the navigation state of the other ship m k is normal, according to the navigation motion parameters included in the real-time navigation parameters of the own ship and the other ship m k and the avoidance responsibility of the own ship and the other ship m k determine the repulsive potential energy of the other ship m k with respect to the own ship

[0066] In one embodiment, based on the navigation motion parameters of the own ship and ship m k and the collision avoidance responsibilities of the own ship and ship m k to determine the repulsive potential energy of ship m k on the own ship, the specific method is as follows: Specifically:

[0067] Based on the navigation motion parameters of the own ship and ship m k to determine the collision risk index I Re ;

[0068] When the collision risk index I Re indicates that there is no collision risk between the own ship and ship m k , it is determined that

[0069] When the collision risk index I Re indicates that there is a collision risk between the own ship and ship m k , based on the collision avoidance responsibilities of the own ship and ship m k to determine the repulsive potential energy of ship m k on the own ship

[0070] The collision risk index I Re can represent the distance change between the two ships, and the specific value of the collision risk index I k can be calculated based on the navigation motion parameters of the own ship and ship m Re . In one embodiment, the navigation motion parameters of each ship include position, course, and speed. Based on the navigation motion parameters of the own ship and ship m k to determine the collision risk index I Re The specific method is as follows:

[0071] Based on the respective positions of the own ship and ship m k to determine the distance d k between the own ship and ship m qk , based on the respective speeds of the own ship and ship m k to determine the relative speed between the own ship and ship m k , based on the respective courses of the own ship and ship m k to determine the course angle θ between the own ship and ship m k ; based on the distance d k between the own ship and ship m qk , relative speed, and course angle θ to determine the collision risk index I k of the own ship and ship m Re . The specific expression of the collision risk index I Re is as follows:

[0072] I Re =Vx d qk cosθ + V y d qk sinθ

[0073] wherein, V x is the component of the relative velocity between the own ship and ship m k on the x-axis of the earth coordinate system, and V y is the component of the relative velocity between the own ship and ship m k on the y-axis of the earth coordinate system, and θ is the course angle between the own ship and ship m k ; when I Re > 0, the distance between the own ship and ship m k is gradually decreasing, and it is determined that there is a collision risk between the two ships; when I Re ≤ 0, the distance between the own ship and ship m k is in a stalemate or gradually increasing, and it is determined that there is no collision risk between the two ships.

[0074] When it is determined that the navigation state of ship m k is normal and there is a collision risk with the own ship, the specific method for determining the repulsive potential energy of ship m k on the own ship according to the avoidance responsibilities of the own ship and ship m k is as follows: When the avoidance responsibility of the own ship is the give-way ship, determine the repulsive potential energy of ship m

[0075] on the own ship k η is the repulsive potential energy coefficient of the give-way ship; when the avoidance responsibility of the own ship is the stand-on ship, determine the repulsive potential energy of ship m 1 on the own ship k

[0076] The present application divides the area around the own ship into areas with different collision risks by setting two distance thresholds. When ship m k sails within the detection range of the own ship, when ship m k enters the safe navigation range of the own ship, ship m k does not affect the navigation state of the own ship, and neither ship needs to take avoidance; when ship m k enters the conventional avoidance range of the own ship, the two ships conduct conventional avoidance in accordance with the COLREG rules; when ship m k enters the emergency avoidance range of the own ship, at this time the collision risk between the two ships increases sharply, and at this time, regardless of whether the own ship is determined to be the give-way ship according to the COLREG rules, the own ship must take avoidance to ensure the safety of the two ships. During the process of ship m k gradually approaching the own ship, in order to ensure that the two ships do not collide, it is necessary to make ship m k ​When entering the emergency avoidance range from the regular avoidance range, the repulsive potential energy of the own ship increases sharply to enable the own ship to quickly leave the area. To achieve this effect, the present application sets the repulsive potential energy coefficient η of the give-way ship 1 and the abnormal ship repulsive potential energy coefficient η 2 to be much smaller than the emergency repulsive potential energy coefficient η 3 . It should be noted that much smaller means that the emergency repulsive potential energy coefficient η 3 is a multiple of the give-way ship repulsive potential energy coefficient η 1 and the abnormal ship repulsive potential energy coefficient η 2 reaching a predetermined threshold. The specific values of η 1 , η 2 , η 3 are determined according to tests. For example, set η 1 = 20, η 2 = 5, η 3 = 100.

[0077] Step 3, calculate the combined potential energy U = U + U received by the own ship based on the gravitational potential energy a of the own ship with respect to the navigation target point of the target route r and the repulsive potential energy of all other ships on the own ship; where ξ is the gravitational potential energy coefficient, d qp is the distance between the navigation target point and the own ship, and I is the total number of other ships within the detection range of the own ship, and the integer parameter I ≥ 1. In the present application, the distance between the navigation target point and the own ship and the distance between the own ship and other ship m k can be determined by conventional distance calculation methods. The present application uses the Euclidean distance calculation method.

[0078] Since there may be multiple other ships encountering the own ship, it is necessary to consider the repulsive potential energy generated by each other ship on the own ship. At the same time, when the own ship is sailing along the target route, it also needs to continuously approach the navigation target point to ensure that the trajectory does not deviate. Therefore, the effect of the navigation target point on the own ship can be regarded as gravity, constantly attracting the own ship to approach the navigation target point. From the calculation formula of gravitational potential energy, it can be seen that as the distance between the own ship and the navigation target point gets closer, the gravitational potential energy becomes smaller, which is to prevent the own ship from passing the navigation target point due to excessive gravitational potential energy when approaching the navigation target point. Among them, the value of the gravitational potential energy coefficient ξ is determined through tests. The principle for the values of the gravitational potential energy coefficient and the repulsive potential energy coefficient is to ensure that the gravitational potential energy and the repulsive potential energy received by the own ship reach a relatively balanced state that is conducive to the safe and stable navigation of the own ship during the entire encounter process, and to avoid the gravitational potential energy or the repulsive potential energy being too large or too small.

[0079] Step 4: Determine the target speed and target rudder angle of the ship in the current encounter situation according to the comprehensive potential energy U and the COLREG rule, and control the collision avoidance navigation of the ship according to the target speed and target rudder angle.

[0080] In one embodiment, the specific method for determining the target speed and target rudder angle of the ship in the current encounter situation according to the comprehensive potential energy U combined with the COLREG rule is:

[0081] Since the ship will move in the direction where the comprehensive potential energy gradient decreases fastest, the comprehensive repulsion F is obtained by differentiating the comprehensive potential energy U. According to the value and direction of the comprehensive repulsion F, the candidate speed and candidate rudder angle of the ship in the current situation are determined.

[0082] Since there may be multiple theoretical values ​​for the magnitude and direction of the repulsive force F, it is also necessary to select candidate speeds and rudder angles that meet the COLREG rule as the target speed and target rudder angle of the ship in the current encounter situation. For example, in an encounter situation, the calculated direction of the repulsive force F may be left or right, but the COLREG rule can only turn right, so the repulsive force direction to the left needs to be eliminated.

[0083] After the target speed and target heading are determined, the corresponding control instructions can be given using existing technical methods, including rudder angle control instructions, main engine control instructions, and thruster control instructions, and the ship can be controlled to avoid collision according to the control instructions. For manned ships, auxiliary navigation suggestions are given according to the control instructions to guide the crew to adjust the ship's heading and speed to complete the encounter. In addition, when determining the target speed and target heading, the marine environmental factors and the ship's maneuverability should also be considered, and the best target speed and target heading should be comprehensively selected.

[0084] It should be noted that since the method of the present application monitors the real-time navigation parameters of the ship and other ships in real time, and uses the comprehensive potential energy to continuously adjust the course and speed of the ship, it can ensure that the movements of the two ships are continuously detected during the entire encounter process. For the situation where the avoidance responsibility of the other ship is to give way but the ship does not cooperate in the avoidance, the method of the present application can also respond and deal with it.

[0085] The above is only a preferred embodiment of the present application, and the present application is not limited to the above embodiments. It is understood that other improvements and changes directly derived or associated by those skilled in the art without departing from the spirit and concept of the present application should be considered to be included in the protection scope of the present application.

Claims

1. A method for autonomous ship collision avoidance based on COLREG rules, characterized in that: The autonomous ship will encounter a collision avoidance method comprising: Obtain the real-time navigation parameters of the own ship and other ships within the detection range; Based on COLREG rules, according to the ship and any other ship within the detection range m k The real-time navigation parameters of the ship are divided into the ship and other ships m k the duty to avoid; According to the ship and other ships k Real-time navigation parameters of own ship and other ships k The avoidance responsibility determines that when the ship is sailing along the target route, other ships m k Repulsive potential energy to own ship Among them, his ship m k The greater the impact on the navigation status of the ship, the greater the repulsive potential energy. The larger the value; The gravitational potential energy of the target point on the target route to the ship and the repulsive potential energy of all other ships on this ship The calculated comprehensive potential energy of the ship is U = U a +U r ; where ξ is the gravitational potential energy coefficient, d qp is the distance between the navigation target point and the ship, I is the total number of other ships within the detection range of the ship, and the integer parameter I≥1; The target speed and target rudder angle of the ship in the current encounter situation are determined according to the comprehensive potential energy U in combination with the COLREG rule, and the collision avoidance navigation of the ship is controlled according to the target speed and target rudder angle.

2. The autonomous ship collision avoidance method according to claim 1, characterized in that: Determine any other ship k Repulsive potential energy to own ship include: Determine the ship and any other ship k The distance d qk ; When qk >d rep When confirming other ships m k Within the safe navigation range of the ship, determine the other ship m k Repulsive potential energy to own ship When qk ≤d emg When confirming other ships m k Within the emergency avoidance range of this ship, determine that the other ship m k Repulsive potential energy to own ship When emg <d qk ≤d rep When confirming other ships m k Within the normal avoidance range of own ship, according to the m k Real-time navigation parameters of other ships k The navigation status of the ship and other ships k The avoidance responsibility of other vessels is determined by k Repulsive potential energy to own ship Among them, d rep is the first distance threshold, d emg is the second distance threshold, and η3 is the emergency repulsive potential energy coefficient.

3. The autonomous ship collision avoidance method according to claim 2, characterized in that: When emg <d qk ≤d rep When determining any other ship m k Repulsive potential energy to own ship include: When he is sure that his ship k When the navigation status of the other ship is abnormal, k Repulsive potential energy to own ship η2 is the potential energy coefficient of abnormal ship repulsion; When he is sure that his ship k When the navigation status is normal, according to the ship and other ships m k The real-time navigation parameters include the navigation motion parameters and the navigation information of the own ship and other ships. k The avoidance responsibility of other vessels is determined by k Repulsive potential energy to own ship 4. The autonomous ship collision avoidance method according to claim 3, characterized in that: According to the ship and other ships k The navigation motion parameters and the m of own ship and other ships k The avoidance responsibility of other vessels is determined by k Repulsive potential energy to own ship include: According to the ship and other ships k Determine the collision risk index I based on the navigation motion parameters Re ; When the collision risk index I Re Instruct own ship and other ships k When there is no risk of collision, confirm When the collision risk index I Re Instruct own ship and other ships k When there is a risk of collision, the ship and other ships k The avoidance responsibility of other vessels is determined by k Repulsive potential energy to own ship 5. The autonomous ship collision avoidance method according to claim 4, characterized in that: According to the ship and other ships m k The avoidance responsibility of other vessels is determined by k Repulsive potential energy to own ship include: When the ship's avoidance obligation is to give way to the vessel, determine the other ship's m k Repulsive potential energy to own ship η1 is the repulsive potential energy coefficient of the give-way ship; When the ship's duty to avoid is to give way to the direct-course ship, determine the other ship's m k Repulsive potential energy to own ship 6. The autonomous ship collision avoidance method according to claim 5, characterized in that: The give-way ship repulsion potential energy coefficient η1 and the abnormal ship repulsion potential energy coefficient η2 are much smaller than the emergency repulsion potential energy coefficient η3.

7. The autonomous ship collision avoidance method according to claim 4, characterized in that: The navigation parameters of each ship include position, heading and speed. k Determine the collision risk index I based on the navigation motion parameters Re include: According to the ship and other ships k The respective positions determine the own ship and other ships m k The distance between qk , according to the ship and other ships m k The speed of each ship determines the speed of the own ship and the other ship m k The relative speed of the ship and the other ship m k The respective headings determine the ship and other ships k The heading angle θ; According to the ship and other ships k The distance between qk , relative speed and heading angle θ determine the ship and the other ship m k Collision risk index I Re .

8. The autonomous ship collision avoidance method according to claim 7, characterized in that: The collision risk index I Re =V x d qk cosθ+V y d qk sinθ, where V x Is this ship and other ships m k The component of the relative velocity on the x-axis of the geodetic coordinate system, V y Is this ship and other ships m k The component of the relative velocity of the ship on the y-axis of the geodetic coordinate system, θ is the m k The heading angle; when I Re >0 to determine the ship and other ships m k There is a risk of collision; when I Re ≤0 to determine the ship and other ships m k There is no risk of collision.

9. The autonomous ship collision avoidance method according to claim 3, characterized in that: The real-time navigation parameters of the other ship include the navigation motion parameters and obstacle avoidance performance status of the other ship, and determine the m k The abnormal navigation status includes: When he was k The obstacle avoidance performance status in the real-time navigation parameters indicates the other ship m k When the obstacle avoidance performance status is abnormal, or when the other ship m k The navigation motion parameters in the real-time navigation parameters detect other ships m k When the navigation stability of the other ship is abnormal, determine k The navigation status is abnormal.

10. The autonomous ship collision avoidance method according to claim 1, characterized in that: According to the comprehensive potential energy U and the COLREG rules, the target speed and target rudder angle of the ship in the current encounter situation are determined as follows: The comprehensive repulsion F is obtained by differentiating the comprehensive potential energy U. According to the value and direction of the comprehensive repulsion F, the candidate speed and candidate rudder angle of the ship in the current encounter situation are determined; The candidate speeds and rudder angles that meet the COLREG rules are selected as the target speed and target rudder angle of the ship in the current encounter situation.

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