An autonomous ship encounter avoidance method based on colreg rules

Abstract

The application discloses an autonomous ship encounter collision avoidance method based on COLREG rules, and relates to the field of autonomous ship control, which comprises the following steps: acquiring real-time sailing parameters of a ship and each other ship in a detection range; dividing the avoidance responsibility of the ship and the other ships based on the COLREG rules; determining the repulsive potential energy of the other ships on the ship when the ship sails along a target course according to the real-time sailing parameters of the ship and the other ships and the avoidance responsibility of the ship and the other ships; calculating the comprehensive potential energy of the ship according to the attractive potential energy of the sailing target point of the target course on the ship and the repulsive potential energy of all the other ships on the ship; and determining the target speed and target rudder angle in combination with the COLREG rules and controlling the ship to sail in an encounter collision avoidance mode. The method can realize real-time monitoring and automatic collision avoidance in the whole encounter process, can solve the collision avoidance problem in all encounter situations, and effectively improves the safety and stability of the autonomous ship.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of autonomous ship control, and in particular to an autonomous ship encounter avoidance method based on COLREG rules. BACKGROUND

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

[0003] Traditional ship collision avoidance methods mainly rely on the experience and judgment of the crew, but in the case of complex and variable marine environment and the increasing number of ships, autonomous ships relying only on the experience of the crew often cannot make timely decisions to cope with changing encounter situations, and cannot meet the needs of safe navigation of autonomous ships. SUMMARY

[0004] In view of the above problems and technical needs, the present application proposes an autonomous ship encounter avoidance method based on COLREG rules, and the technical scheme of the present application is as follows:

[0005] An autonomous ship encounter avoidance method based on COLREG rules, comprising the following steps:

[0006] Obtaining real-time navigation parameters of the ship and each other ship in the detection range;

[0007] Based on the COLREG rules, dividing the avoidance responsibility of the ship and any other ship m k in the detection range according to the real-time navigation parameters of the ship and the other ship m k ;

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

[0009] According to the gravitational potential energy of the target route to the ship and the repulsive potential energy of all other ships to the ship , calculating the comprehensive potential energy U received by the ship U a +U r ; wherein ξ is the gravitational potential energy coefficient, d qpis the distance between the target point and the ship, I is the total number of the other ships in the detection range of the ship, and the integer parameter I≥1;

[0010] The target speed and target rudder angle of the ship in the current encounter situation are determined according to the comprehensive potential energy U and the COLREG rules, and the ship is controlled to avoid collision according to the target speed and target rudder angle.

[0011] A further technical solution is to determine the repulsive potential energy of any other ship m k to the ship , including:

[0012] The distance d k between the ship and any other ship m qk is determined.

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

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

[0015] When d emg <d qk ≤d rep , it is determined that the other ship m k is within the regular avoidance range of the ship, and the repulsive potential energy of the other ship m k to the ship k is determined according to the real-time navigation parameters of the ship and the other ship m k , the navigation state of the other ship m k , and the avoidance responsibility of the ship and the other ship m

[0016] Wherein, d rep is the first distance threshold, d emg is the second distance threshold, and η3 is the emergency repulsive potential energy coefficient.

[0017] A further technical solution is to determine the repulsive potential energy of any other ship m k to the ship , including:

[0018] When it is determined that the navigation state of the other ship m k is abnormal, the repulsive potential energy of the other ship m k to the ship η2 is the abnormal ship repulsion potential energy coefficient;

[0019] When it is determined that the sailing state of the ship m k is normal, the repulsion potential energy of the ship m k to the ship is determined according to the sailing motion parameters contained in the real-time sailing parameters of the ship and the ship m k and the avoidance responsibility of the ship and the ship m k .

[0020] A further technical solution is that the repulsion potential energy of the ship m k to the ship is determined according to the sailing motion parameters of the ship and the ship m k and the avoidance responsibility of the ship and the ship m k . It includes:

[0021] The collision risk index I k is determined according to the sailing motion parameters of the ship and the ship m Re .

[0022] When the collision risk index I Re indicates that there is no collision risk between the ship and the ship m k , it is determined that

[0023] When the collision risk index I Re indicates that there is a collision risk between the ship and the ship m k , the repulsion potential energy of the ship m k to the ship is determined according to the avoidance responsibility of the ship and the ship m k .

[0024] A further technical solution is that the repulsion potential energy of the ship m k to the ship is determined according to the avoidance responsibility of the ship and the ship m k . It includes:

[0025] When the avoidance responsibility of the ship is the yielding ship, the repulsion potential energy of the ship m k to the ship is determined. η1 is the yielding ship repulsion potential energy coefficient;

[0026] When the avoidance responsibility of the ship is the straight-ahead ship, the repulsion potential energy of the ship m k to the ship is determined.

[0027] A further technical solution is that the yielding 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.

[0028] Its further technical solution is that the navigation motion parameters of each ship include position, course, and speed, based on the ship's own speed and that of other ships. k The navigation motion parameters determine the collision risk index I Re include:

[0029] According to this ship and other ships m k Each vessel's position determines the position of itself and other vessels. k The distance d between qk According to the ship and other ships m k Each ship's speed determines the speed of the other ship (m). k The relative speed between the ship and other ships, based on the speed of the ship and other ships (m). k Each vessel's course determines its own course and that of other vessels. k The heading angle θ;

[0030] According to this ship and other ships m k The distance d between qk The relative speed and the heading angle θ determine the distance between the ship and other ships. k Collision risk index I Re .

[0031] Its further technical solution is a collision risk index I. Re =V x d qk cosθ+V y d qk sinθ, where V x Is this ship or another ship m k The relative velocity component along the x-axis in the geodetic coordinate system, V y Is this ship or another ship m k The relative velocity component along the y-axis in the geodetic coordinate system, θ being the velocity of the ship relative to the other ship m. k The heading angle; when I Re >0 determines whether this ship or other ships are m k There is a risk of collision; when I Re When ≤0, determine the m of this ship and other ships. k There is no risk of collision.

[0032] A further technical solution involves using the real-time navigation parameters of other vessels, including their motion parameters and obstacle avoidance performance status, to determine the other vessel's m k Abnormal navigation status includes:

[0033] When his ship m k The obstacle avoidance performance status in the real-time navigation parameters indicates the status of other vessels. k When the obstacle avoidance performance is abnormal, or when it is based on the other ship's m k The navigation motion parameters in the real-time navigation parameters detected other ships m kwhen the sailing stability of the autonomous ship is abnormal, determining the target sailing state of the autonomous ship m k when the sailing stability of the autonomous ship is abnormal.

[0034] A further technical solution is to determine the target sailing speed and target rudder angle of the autonomous ship in the current encounter situation according to the comprehensive potential energy U combined with the COLREG rules, including:

[0035] The comprehensive repulsive force F is obtained by derivation of the comprehensive potential energy U, and the candidate sailing speed and candidate rudder angle of the autonomous ship in the current encounter situation are determined according to the value and direction of the comprehensive repulsive force F;

[0036] The candidate sailing speed and rudder angle that meet the COLREG rules are screened out as the target sailing speed and target rudder angle of the autonomous ship in the current encounter situation.

[0037] The beneficial technical effects of the present application are:

[0038] The autonomous ship encounter avoidance method based on the COLREG rules proposed in the present application realizes the full-process automatic collision avoidance of the autonomous ship in all encounter situations, effectively improves the precision and timeliness of the collision avoidance process compared with the traditional method relying on human experience, and guarantees the safe and stable sailing of the autonomous ship.

[0039] The potential energy method comprehensively considers the attraction of the sailing target point to the autonomous ship and the repulsion of all other ships to the autonomous ship, ensures that the autonomous ship can effectively avoid other ships during continuous progress towards the sailing 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 scene of multi-ship encounter. At the same time, the target heading and target speed obtained by using the comprehensive potential energy are used for collision avoidance while complying with the provisions of the COLREG rules, ensuring that the results of the target heading and target speed obtained are reliable, further improving the safety of the autonomous ship, reducing the probability of collision accidents of the autonomous ship, and thus promoting the smoothness of maritime traffic safety. BRIEF DESCRIPTION OF DRAWINGS

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

[0041] Figure 2 is a flowchart of the autonomous ship encounter avoidance method.

[0042] Figure 3 is an encounter situation judgment diagram. DETAILED DESCRIPTION

[0043] The specific embodiments of the present application will be further described below in conjunction with the drawings.

[0044] Utilizing Figure 1 The autonomous ship navigation system shown in the figure executes an autonomous ship encounter avoidance method based on COLREG rules proposed in the present application.

[0045] The navigation system includes a perception module, an autonomous decision module, and a control module. The perception module obtains real-time navigation parameters, ship length, ship draft, attribute information such as sidelight signals, and marine environmental information of the sea area where the autonomous ship is located of the autonomous ship and other ships within its detection range through radar systems, automatic identification systems, and video monitoring equipment carried on the autonomous ship. The autonomous decision module uses the information obtained by the perception module to automatically divide the avoidance responsibilities of the ship and the other ships, and gives an avoidance decision to successfully complete the current encounter situation. The control module generates control instructions according to the avoidance decision given by the autonomous decision module and controls the autonomous ship to avoid collision or gives an auxiliary navigation suggestion that can solve the current encounter situation.

[0046] Based on the autonomous ship navigation system, the autonomous ship encounter avoidance method based on COLREG rules proposed in the present application, please refer to the flow chart shown in Figure 2 , the specific steps are:

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

[0048] COLREG rules are the International Convention on Regulations for Preventing Collisions at Sea, which is a key specification for global maritime traffic management. Its core purpose is to reduce maritime collision accidents and fully protect ship navigation safety. The rules make detailed provisions for ship lights, signals, navigation marks, and collision avoidance rules to ensure that ships can take the correct action in complex and changing marine environments. At the current stage, COLREG rules provide a unified and clear standard for global maritime ship encounter situations, so the autonomous ship encounter avoidance method of the present application is based on this rule.

[0049] When the autonomous ship is sailing on the sea, the real-time navigation parameters of the ship and each other ship within the detection range are obtained in real time, and the current encounter situation is determined according to the position, speed and heading in the real-time navigation parameters.

[0050] According to the provisions of the COLREG rules on encounter situations, please refer to Figure 3 , OS in the figure represents the ship, and COG represents the ship's ground heading. Taking the heading of the ship as the dividing line, the position angle of the other ship m k relative to the ship is divided into five regions. Regions a and b in the figure represent the other ship mk The position is on the direction of this ship's advance, according to the other ships' m k The relationship between the course of another vessel and the course of the main vessel can be categorized into encounter or overtaking situations, when the other vessel is on the course of another. k If the ship is located in area a, a situation of either a left-side encounter or a left-side overtaking maneuver will occur when the other ship is at position m. k If the ship is located in area b, a right-side encounter or right-side overtaking situation will occur. Area c in the diagram represents the other ship m. k Located on the starboard side of this vessel, whether a crossover encounter is possible can be determined by whether the two vessels' courses intersect. Area d in the diagram represents the other vessel m. k Located within 22.5° aft of the port and starboard sides of this vessel, other vessels m k If another vessel's course is similar to that of our vessel and its speed is greater, an overtaking situation will arise, and our vessel will be the one being overtaken. Area e in the diagram represents the other vessel m. k On the port side of this vessel, whether a crossover encounter has occurred can be determined by whether the course of the two vessels intersects.

[0051] Once the current encounter situation is determined, the relevant provisions of the COLREG Code concerning vessel encounters can be consulted to classify the situation between the vessel and the other vessel in the current encounter situation according to the rules. k The responsibility for avoiding obstacles. In the case of a cross encounter, it is necessary to distinguish between the vessel traveling in the straight and the vessel giving way. If an overtaking situation occurs, the vessel is the vessel giving way. If the vessel is being overtaken, the vessel is the vessel traveling in the straight. If a head-on encounter occurs, both vessels are the vessels giving way to each other.

[0052] Step 2, based on the situation of this ship and other ships m k Real-time navigation parameters of this ship and other ships k The responsibility for avoiding collisions is determined when the vessel is sailing along the target route and another vessel is involved. k Repulsive potential energy of the ship Among them, his ship m k The greater the impact on the ship's navigation status, the greater the repulsive potential energy. The larger the value, the better.

[0053] When an autonomous vessel is sailing along a target route at sea, it needs to continuously move towards the target navigation point in the target route. In this process, it will be affected by other vessels. In order to avoid collision with other vessels, the vessel needs to move away from other vessels. Therefore, this application achieves the effect of moving away from other vessels by analyzing the repulsive potential energy of other vessels on the vessel.

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

[0055] According to this ship and other ships m k Real-time navigation parameters determine the relationship between this vessel and any other vessel. kdistance d qk ;

[0056] When d qk >d rep When to determine his ship m k Within the safe navigation range of this vessel, determine the location of other vessels. k Repulsive potential energy of the ship Other vessels within the safe navigation range of this vessel k It will not affect the ship's navigation status;

[0057] When d qk ≤d emg When to determine his ship m k Within the emergency avoidance range of this vessel, determine the location of the other vessel m k Repulsive potential energy of the ship η3 is the emergency repulsive potential energy coefficient; other vessels within the emergency avoidance range of this vessel... k The closer the distance to this ship, the greater the impact on this ship's navigation status;

[0058] When d emg <d qk ≤d rep When to determine his ship m k Within the vessel's normal avoidance range, according to the rules regarding the collision avoidance of this vessel and other vessels... k Real-time navigation parameters of other ships k The navigation status and the status of this ship and other ships m k Determining the responsibility for avoidance of other vessels k Repulsive potential energy of the ship

[0059] Where, d rep It is the first distance threshold, d emg It is the second distance threshold, d emg <d rep Each distance threshold is determined based on a combination of factors, including the ship's maneuverability, speed, and the current marine environment. When the distance between the two ships is less than d... emg This indicates that the encounter between the two ships has become extremely urgent, and emergency collision avoidance measures must be initiated immediately. First distance threshold d rep Second distance threshold d emg The specific value can be customized based on practical experience or simulation calculations.

[0060] Specifically, when d emg <d qk ≤d rep At that time, determine any one of his ships m k Repulsive potential energy of the ship The method is as follows:

[0061] Firstly, the sailing state of the other ship m k is judged, and when it is determined that the sailing state of the other ship m k is abnormal, the repulsive potential energy of the other ship m k to the subject ship is determined. η2 is the abnormal ship repulsive potential energy coefficient.

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

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

[0064] Among them, the obstacle avoidance performance parameter is used to characterize the working state of the other ship m k , when the other ship m k is a restricted ship, a loss-of-control ship or a fishing ship engaged in trawl operation, the other ship m k cannot avoid obstacles, and its obstacle avoidance performance state is abnormal. On the other hand, the sailing stability of the other ship m k is judged by detecting the sailing motion parameters of the other ship m k , and whether the heading of the other ship m k is clear and stable is determined by detecting the changes of the heading and trajectory of the other ship m k in a period of time, and when the heading and trajectory of the other ship m k abnormally change, it is determined that the sailing state of the other ship m k is abnormal. The specific abnormality detection method can use the method of the prior art, and the present application will not be described here.

[0065] When it is determined that the sailing state of the other ship m k is normal, the repulsive potential energy of the other ship m k to the subject ship is determined according to the sailing motion parameters contained in the real-time sailing parameters of the subject ship and the other ship m k and the collision avoidance responsibility of the subject ship and the other ship m k .

[0066] In an embodiment, the repulsive potential energy of the other ship m k to the subject ship is determined according to the sailing motion parameters of the subject ship and the other ship m k and the collision avoidance responsibility of the subject ship and the other ship m k . The specific method is as follows:

[0067] According to this ship and other ships m k The navigation motion parameters determine the collision risk index I Re ;

[0068] When collision risk index I Re Instructions for this vessel and other vessels m k When there is no risk of collision, determine

[0069] When collision risk index I Re Instructions for this vessel and other vessels m k When there is a risk of collision, the collision risk shall be determined according to the distance between the vessel and the other vessel. k Determining the responsibility for avoidance of other vessels k Repulsive potential energy of the ship

[0070] Collision Risk Index I Re It can represent the change in distance between two ships, and can be determined based on the distance between the ship and the other ship (m). k The collision risk index I is calculated using navigation motion parameters. Re The specific values. In one embodiment, the navigation motion parameters of each ship include position, heading, and speed, depending on the ship's position and speed compared to other ships. k The navigation motion parameters determine the collision risk index I Re The specific method is as follows:

[0071] According to this ship and other ships m k Each vessel's position determines the position of itself and other vessels. k The distance d between qk According to the ship and other ships m k Each ship's speed determines the speed of the other ship (m). k The relative speed between the ship and other ships, based on the speed of the ship and other ships (m). k Each vessel's course determines its own course and that of other vessels. k The course angle θ; based on the m of this ship and other ships. k The distance d between qk The relative speed and the heading angle θ determine the distance between the ship and other ships. k Collision risk index I Re Collision Risk Index I Re The specific expression is:

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

[0073] Among them, V xIs this ship or another ship m k The relative velocity component along the x-axis in the geodetic coordinate system, V y Is this ship or another ship m k The relative velocity component along the y-axis in the geodetic coordinate system, θ being the velocity of the ship relative to the other ship m. k The heading angle; when I Re >0 o'clock, this ship and other ships m k The distance between the two ships is gradually decreasing, confirming a risk of collision; when I Re When ≤0, the m of this ship and other ships k The distance between the two ships is either at a stalemate or gradually increasing, and it has been determined that there is no risk of collision between the two ships.

[0074] When it is determined that his ship is m k When the navigation status is normal and there is a risk of collision with this vessel, according to the conditions of this vessel and other vessels, m k Determining the responsibility for avoidance of other vessels k Repulsive potential energy of the ship The specific method is as follows:

[0075] When the vessel's responsibility for yielding is to give way to the other vessel, determine the other vessel's position. k Repulsive potential energy of the ship η1 is the repulsive potential energy coefficient of the giving vessel; when the vessel's responsibility for avoiding the obstacle lies with the vessel traveling in the straight path, determine the other vessel's m. k Repulsive potential energy of the ship

[0076] This application divides the area around the vessel into zones with different collision risks by setting two distance thresholds. Other vessels (m) k When navigating within the detection range of this vessel, when other vessels... k When entering the safe navigation range of this vessel, other vessels m k This does not affect the navigation status of this vessel, and neither vessel needs to give way; when another vessel... k When entering the normal avoidance range of this vessel, both vessels shall conduct normal avoidance in accordance with the COLREG Code; when another vessel enters the normal avoidance range, both vessels shall conduct normal avoidance in accordance with the COLREG Code; k Upon entering the emergency avoidance zone of this vessel, the risk of collision between the two vessels increases dramatically. Regardless of whether the COLREG rules determine that this vessel is the give-way vessel, it must give way to ensure the safety of both vessels. (The last sentence appears to be incomplete and unrelated to the preceding text.) k As the vessel gradually approaches, in order to ensure that the two vessels do not collide, it is necessary to make the other vessel... kWhen entering the emergency avoidance range from the normal avoidance range, the repulsive potential energy of the target ship to the subject ship is sharply increased to make the subject ship quickly leave the area. In order to achieve this effect, the subject ship repulsive potential energy coefficient η1 and the abnormal ship repulsive potential energy coefficient η2 are set to be much smaller than the emergency repulsive potential energy coefficient η3. It should be noted that much smaller means that the emergency repulsive potential energy coefficient η3 is a multiple of the subject ship repulsive potential energy coefficient η1 and the abnormal ship repulsive potential energy coefficient η2, reaching a predetermined threshold. The specific values of η1, η2 and η3 are determined by experiments, for example, η1 = 20, η2 = 5 and η3 = 100.

[0077] Step 3, calculating the attractive potential energy of the target point of the target route to the subject ship and the repulsive potential energy of all other ships to the subject ship The comprehensive potential energy U of the subject ship is calculated as follows: a + U r ; wherein ξ is the attractive potential energy coefficient, d qp is the distance between the target point and the subject ship, I is the total number of other ships within the detection range of the subject ship, and the integer parameter I ≥ 1. In the present application, the distance between the target point and the subject ship and the distance between the subject ship and the other ship m k can be determined by using a conventional distance calculation method, and the Euclidean distance calculation method is used in the present application.

[0078] Since there may be multiple other ships encountering the subject ship, the repulsive potential energy of each other ship to the subject ship needs to be considered. At the same time, the subject ship needs to continuously approach the target point of the target route to ensure that the trajectory does not deviate. Therefore, the effect of the target point on the subject ship can be regarded as an attractive force, which constantly attracts the subject ship to the target point. As can be seen from the calculation formula of the attractive potential energy, the closer the subject ship is to the target point, the smaller the attractive potential energy, which is to prevent the subject ship from overshooting the target point due to excessive attractive potential energy when approaching the target point. The value of the attractive potential energy coefficient ξ is determined by experiments. The principle of determining the values of the attractive potential energy coefficient and the repulsive potential energy coefficient is to ensure that the attractive potential energy and the repulsive potential energy of the subject ship reach a relatively balanced state during the entire encounter process, which is beneficial to the safe and stable navigation of the subject ship, and avoids excessive or insufficient attractive potential energy or repulsive potential energy.

[0079] Step 4, determining the target speed and target rudder angle of the subject ship in the current encounter situation according to the comprehensive potential energy U combined with the COLREG rules, and controlling the collision avoidance navigation of the subject 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 subject ship in the current encounter situation according to the comprehensive potential energy U combined with the COLREG rules is as follows:

[0081] Since the ship will move in the direction of the fastest descent of the comprehensive potential gradient, the comprehensive repulsive force F is obtained by derivation of the comprehensive potential U, and the candidate speed and the candidate rudder angle of the ship in the current encounter situation are determined according to the value and direction of the comprehensive repulsive force F.

[0082] Since there may be multiple theoretical values of the value and direction of the repulsive force F, the candidate speed and the rudder angle that meet the COLREG rules are selected as the target speed and the target rudder angle of the ship in the current encounter situation. For example, in the head-on situation, the direction of the calculated repulsive force F may have two directions of left and right, and the COLREG rules can only turn right, so the left direction of the repulsive force is removed.

[0083] After the target speed and the target heading are determined, the corresponding control instructions can be given by using the existing technical method, including the rudder angle control order, the main engine control instruction and the side thrust control instruction, and the ship is controlled to avoid collision according to the control instructions. For the manned ship, the auxiliary navigation suggestion is given according to the control instructions to guide the crew to adjust the heading and speed of the ship to complete the encounter. In addition, when determining the target speed and the target heading, the ocean environmental factors and the maneuvering performance of the ship are also considered to comprehensively select the best target speed and target heading.

[0084] It should be noted that since the method of the present application monitors the real-time navigation parameters of the ship and each other ship in real time, and continuously adjusts the heading and speed of the ship by using the comprehensive potential, the movement of the two ships can be continuously detected during the entire encounter process. For the case that the other ship is the giving-way ship but does not cooperate with the avoidance, the method of the present application can also handle it.

[0085] The above is only the preferred embodiment of the present application, and the present application is not limited to the above embodiments. It can be understood that other improvements and changes directly derived or thought 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. An autonomous ship collision avoidance method based on COLREG rules, characterized in that, The autonomous ship collision avoidance method comprises the following steps: Obtaining real-time sailing parameters of the ship and each other ship in the detection range; Based on the COLREG rules, and considering both the vessel and any other vessel within the detection range... Real-time navigation parameters distinguish this vessel from other vessels The responsibility to avoid; According to this ship and other ships Real-time navigation parameters of this ship and other ships The responsibility for avoidance is determined when the vessel is sailing along the target route and another vessel... Repulsive potential energy of the ship Among them, his ship The greater the impact on the ship's navigation status, the greater the repulsive potential energy. The larger the value; The gravitational potential energy of the target point of the target course to the ship and the repulsive potential energy of all other ships to the ship The comprehensive potential energy of the ship is calculated ; wherein, is the gravitational potential energy coefficient, is the distance between the target point and the ship, is the total number of other ships within the detection range of the ship, an integer parameter ≥ 1; According to the integrated potential energy U The target speed and target rudder angle of the ship in the current encounter situation are determined in combination with the COLREG rules, and the ship is controlled to avoid collision according to the target speed and target rudder angle. According to the comprehensive potential energy U The target speed and target rudder angle of the ship in the current encounter situation are determined in combination with the COLREG rules. Comprehensive potential energy U Differentiation yields the combined repulsive force F According to the comprehensive repulsive force F The magnitude and direction of the value determine the candidate speed and candidate rudder angle of the ship in the current encounter situation; Screening candidate sailing speed and rudder angle meeting the COLREG rule as the target sailing speed and target rudder angle of the ship in the current encounter situation.

2. The autonomous vessel collision avoidance method according to claim 1, characterized in that, determining any of his ships repulsive potential energy to the ship comprising: Determine the relationship between this vessel and any other vessel. distance ; When he determines that the other ship is within the safe navigation range of the own ship, determines that the other ship has repulsive potential energy =0; When he determines that the other ship is within the emergency avoidance range of the own ship, the own ship determines that the other ship is within the emergency avoidance range of the own ship, the own ship repulsive potential energy of the other ship to the own ship ; When he ship is determined to be within the regular avoidance range of the subject ship, the repulsive potential energy of the he ship to the subject ship is determined according to the real-time sailing parameters of the subject ship and the he ship, the sailing state of the he ship, and the avoidance responsibilities of the subject ship and the he ship. ;​​​​​ wherein, is a first distance threshold, is a second distance threshold, is an emergency repulsive potential coefficient.

3. The autonomous vessel collision avoidance method according to claim 2, characterized in that, When any of his ships repulsive potential to the ship includes: When determining that the sailing state of the other ship is abnormal, the repulsive potential energy of the other ship to the own ship is determined , is an abnormal ship repulsive potential energy coefficient; When it is confirmed that his ship When the navigation status is normal, according to the ship's and other ships' conditions The real-time navigation parameters include navigation motion parameters of the ship itself and other ships. Determining the responsibility for avoiding collisions with other vessels Repulsive potential energy of the ship .

4. The autonomous vessel collision avoidance method according to claim 3, characterized in that, According to the sailing motion parameters of the own ship and the other ship and the avoidance responsibilities of the own ship and the other ship, the other ship is determined repulsive potential of the other ship to the own ship​​​ A collision risk indicator is determined based on the sailing motion parameters of the own ship and the other ship ;​ when the risk of collision indicator indicates that the own ship and the other ship when there is no risk of collision, determining ; When the risk of collision indicator indicates that the own ship and the other ship are at risk of collision, the other ship is determined according to the avoidance responsibility of the own ship and the other ship repulsive potential energy of the own ship 5. The autonomous vessel collision avoidance method according to claim 4, characterized in that, According to the avoidance responsibility of the own ship and the other ship determines the other ship repulsive potential energy of the own ship includes: When the ship's obligation is to give way, determine the other ship repulsive potential of the own ship , is the repulsive potential of the give-way ship When the ship's duty of avoidance is the overtaking ship, determine his ship Potential repulsion of the ship .

6. The autonomous vessel collision avoidance method according to claim 5, characterized in that, The yielding ship repulsive potential energy coefficient And the abnormal ship repulsive potential energy coefficient Less than the emergency repulsive potential energy coefficient .

7. The autonomous vessel collision avoidance method of claim 4, wherein, The navigation motion parameters of each ship include position, heading and speed, and the collision risk index is determined according to the navigation motion parameters of the own ship and the other ship includes:​ According to this ship and other ships Each vessel's position determines its position relative to other vessels. Distance between According to the ship and other ships Each vessel's speed determines its speed relative to other vessels. The relative speed, based on the speed of this ship and other ships Each vessel's course determines its course with that of other vessels. The heading angle ; According to this ship and other ships Distance between Relative speed and heading angle Determine the relationship between this vessel and other vessels Collision risk indicators .

8. The autonomous vessel collision avoidance method according to claim 7, characterized in that, The collision risk index ,in, Is it this ship or another ship? The relative velocity component along the x-axis in the geodetic coordinate system. Is it this ship or another ship? The relative velocity component along the y-axis in the geodetic coordinate system. Is it this ship or another ship? The heading angle; when Determine the time when this vessel is in contact with other vessels There is a risk of collision; when Determine the time when this vessel is in contact with other vessels There is no risk of collision.

9. The autonomous vessel collision avoidance method of claim 3, wherein, The real-time sailing parameters of the ego ship include sailing motion parameters of the ego ship and obstacle avoidance performance states, and the sailing state anomaly of the ego ship is determined according to the real-time sailing parameters of the ego ship includes that when his ship The obstacle avoidance performance status in the real-time navigation parameters indicates the status of other vessels. When the obstacle avoidance performance is abnormal, or when it is based on other ships The navigation motion parameters in the real-time navigation parameters detected other ships. When the navigation stability is abnormal, determine the location of other vessels. The navigation status is abnormal.

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