A collision avoidance navigation method based on the International Regulations for Preventing Collisions at Sea

Abstract

The present invention discloses a collision avoidance navigation method based on the International Regulations for Preventing Collisions at Sea, including: S1: when another ship enters the radar range of the own ship, obtain the minimum encounter time, the minimum encounter distance, the dimensionless ratio of the ship's advance distance to the ship's length, and the dimensionless ratio of the ship's initial turning path to the ship's length; S2: obtain the basic parameters of the ship field dynamic model, and calculate the coordinates of the characteristic points in the ship field; S3: obtain the judgment result of the encounter situation between the own ship and the other ship; S4: navigate the own ship to ensure the safety of the encounter navigation. The present invention establishes a ship dynamic model according to the coordinates of each characteristic point in the ship field, judges the encounter situation of the ship, and then navigates the own ship to ensure the safety of the encounter navigation. The method of converting the encounter situation divided in COLREGS into a mathematical judgment condition assists the ship in making collision avoidance action decisions, and can safely, standardizedly and effectively complete the collision avoidance action of the ship encounter situation.

Description

Technical Field

[0001] The invention relates to the technical field of ship navigation collision avoidance, and in particular to a collision avoidance navigation method based on international maritime collision avoidance regulations. Background Art

[0002] Ships sailing at sea comply with the International Regulations for Preventing Collisions at Sea (COLREGS) to prevent and reduce misjudgment of ship encounter situations, ensure safe and orderly maritime traffic, and avoid collisions during navigation. However, COLREGS only has semantic expressions for the judgment of encounter situations and collision avoidance actions. In actual navigation, the crew's judgment of encounter situations and decision-making on collision avoidance actions are relatively subjective, and they rely too much on experience and cannot formulate collision avoidance action plans in a timely, safe and effective manner. Therefore, how to convert the encounter, overtaking and crossing encounter situations divided in COLREGS into mathematical judgment conditions to constrain them, and plan the ship's collision avoidance actions safely and scientifically is a very critical issue. With the development of ship autonomous driving technology, the solution to this problem has obvious practical significance. Summary of the invention

[0003] The present invention provides a collision avoidance navigation method based on the International Regulations for Avoiding Collisions at Sea to overcome the above technical problems.

[0004] To achieve the above object, the technical solution of the present invention is as follows:

[0005] A collision avoidance navigation method based on international regulations for avoiding collisions at sea comprises the following steps:

[0006] S1: When the other ship enters the radar range of our ship, obtain the current position coordinates of our ship, the current position coordinates of the other ship, the current speed of our ship, and the current speed of the other ship to obtain the minimum encounter time T CPA , minimum encounter distance D CPA , the dimensionless ratio k of the ship's advance distance to the ship's length AD , the dimensionless ratio k of the ship's initial turning diameter to its length DT ;

[0007] S2: According to the current position coordinates of the own ship, the current position coordinates of other ships, the current speed of the own ship, and the current speed of other ships, the basic parameters of the dynamic model of the ship field are obtained, and the coordinates of the characteristic points of the ship field are calculated to establish the dynamic model of the ship field;

[0008] The characteristic points in the ship field include: a frontmost characteristic point F indicating the ship's forward direction in the ship field; a port front characteristic point P indicating the ship's forward direction in the ship field; f ; Indicates the feature point P perpendicular to the port side of the ship's forward direction in the ship field n ; Indicates the port rear feature point P of the ship's forward direction in the ship fieldb ; The most distal feature point B indicating the forward direction of the ship in the ship domain; The starboard forward feature point S indicating the forward direction of the ship in the ship domain f ; The feature point S perpendicular to the starboard side in the forward direction of the ship in the ship domain n ; The starboard aft feature point S indicating the forward direction of the ship in the ship domain b ;

[0009] S3: According to the current heading angle of the own ship and the current heading angle of the other ship, based on the collision risk assessment module of the International Regulations for Preventing Collisions at Sea (COLREGS), obtain the judgment result of the encounter situation between the own ship and the other ship;

[0010] S4: According to the judgment result of the encounter situation between the own ship and the other ship, and based on the ship collision avoidance navigation module of the International Regulations for Preventing Collisions at Sea (COLREGS), navigate the own ship to ensure the safety of the encounter navigation.

[0011] Beneficial effects: An anti-collision navigation method based on the International Regulations for Preventing Collisions at Sea (COLREGS) of the present invention can obtain the basic parameters of the ship domain dynamic model based on the coordinates and speed information of the own ship and the other ship, calculate the coordinates of each feature point in the ship domain, establish a ship dynamic model, and judge the encounter situation of the ship according to the collision risk assessment module based on the International Regulations for Preventing Collisions at Sea (COLREGS). And according to the encounter situation of the ship, based on the ship collision avoidance navigation module of the International Regulations for Preventing Collisions at Sea (COLREGS), navigate the own ship to ensure the safety of the encounter navigation. The present invention converts the head-on, overtaking, and crossing encounter situations defined in the COLREGS into mathematical judgment conditions, combines with the ship domain which is of great significance to ship navigation safety, so as to assist the ship in making anti-collision action decisions and navigate the ship, and can safely, regularly and effectively complete the anti-collision actions in the ship encounter situation. Description of the Drawings

[0012] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the following drawings are some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0013] Figure 1 It is a flowchart of the anti-collision navigation method based on the International Regulations for Preventing Collisions at Sea (COLREGS) of the present invention;

[0014] Figure 2 It is a navigation schematic diagram of the head-on encounter situation of the present invention;

[0015] Figure 3 It is a schematic diagram 1 of the port side overtaking situation of the present invention;

[0016] Figure 4 It is a schematic diagram of the port side overtaking situation 2 of the present invention;

[0017] Figure 5 It is a schematic diagram of the port side overtaking situation 3 of the present invention;

[0018] Figure 6 It is a schematic diagram of a small-angle intersection situation 1 of the present invention;

[0019] Figure 7 This is a schematic diagram of a small-angle intersection situation 2 of the present invention;

[0020] Figure 8 It is a schematic diagram of a large-angle intersection situation 1 of the present invention;

[0021] Fig. 9 This is a schematic diagram of a large-angle intersection situation 2 of the present invention;

[0022] Fig.10 This is a schematic diagram of a large-angle intersection situation 3 of the present invention;

[0023] Fig.11 This is a schematic diagram of a large-angle intersection situation 4 of the present invention;

[0024] Fig.12 It is a schematic diagram of the dynamic model of the hexagonal ship field of the present invention;

[0025] Fig.13 A schematic diagram of a ship area established when another ship is detected in an embodiment of the present invention;

[0026] Fig.14 It is a schematic diagram of the ship deviating from the original route and heading for the navigation point in an embodiment of the present invention;

[0027] Fig.15 A schematic diagram of switching navigation points in an embodiment of the present invention;

[0028] Fig.16 It is a schematic diagram of the ship ending the collision avoidance action and heading to the original destination in an embodiment of the present invention. DETAILED DESCRIPTION

[0029] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0030] A collision avoidance navigation method based on international regulations for avoiding collisions at sea, comprising the following steps: Figure 1 As shown:

[0031] S1: When the other ship enters the radar range of the own ship, the ship's current position coordinates, the other ship's current position coordinates, the current speed of the own ship, the current speed of the other ship, and the heading angle between the own ship and the other ship are obtained through the ship's onboard equipment to obtain the minimum encounter time T CPA , minimum encounter distance D CPA , the dimensionless ratio k of the ship's advance distance to the ship's length AD , the dimensionless ratio k of the ship's initial turning diameter to its length DT ;

[0032] Preferably, in S1, the minimum encounter time T CPA , minimum encounter distance D CPA , the dimensionless ratio k of the ship's advance distance to the ship's length AD , the dimensionless ratio k of the ship's turning diameter to its length DT Get as follows:

[0033] According to the collision risk assessment module, the coordinates of the own ship and the other ship are obtained by the shipborne equipment, and the distance between the two ships is obtained as follows:

[0034] p 1 =(x 1 ,y 1 ) (1)

[0035] p 2 =(x 2 ,y 2 ) (2)

[0036] p 3 =p 1 -p 2 (3)

[0037] Among them, p 1 is the current position coordinate of the ship, p 2 is the current position coordinate of the other ship, p 3 is the relative position vector of the two ships; x 1 is the horizontal coordinate of the current position of the ship; 1 is the ordinate of the current position of the ship; x 2 is the horizontal coordinate of the current position of the other ship; 2 is the ordinate of the current position of the other ship; wherein, the coordinate system in this embodiment adopts the geodetic coordinate system.

[0038] Then T CPA and D CPA for:

[0039]

[0040] D CPA =|(p 1 +T CPA ·v 1 )-(p 2 +T CPA ·v 2 )| (5)

[0041] Where, T CPA is the minimum encounter time, in seconds; D CPA is the minimum encounter distance in meters; v 1 is the current speed of the ship, v 2 is the current speed of the other ship, in meters per second; the minimum encounter time T CPA and the minimum encounter distance D CPA It means that if the two ships continue to sail at the current speed, they will reach T CPA D CPA , usually D when sailing at sea CPA Measuring the risk of collision between two ships when they meet;

[0042] k AD and k DT for:

[0043]

[0044] Where: V is the ship speed in knots; A D D is the ship's advance distance; T is the initial diameter of the cycle;

[0045] S2: According to the current position coordinates of the own ship, the current position coordinates of other ships, the current speed of the own ship, and the current speed of other ships, the basic parameters of the dynamic model of the ship field are obtained, and the coordinates of the characteristic points of the ship field are calculated to establish the dynamic model of the ship field;

[0046] The characteristic points in the ship field include: a frontmost characteristic point F indicating the ship's forward direction in the ship field; a port front characteristic point P indicating the ship's forward direction in the ship field; f ; Indicates the feature point P perpendicular to the port side of the ship's forward direction in the ship field n ; Indicates the port rear feature point P of the ship's forward direction in the ship field b ; represents the most terminal feature point B in the ship's forward direction in the ship field; represents the starboard front feature point S in the ship's forward direction in the ship field f ; Indicates the characteristic point S perpendicular to the starboard side of the ship's forward direction in the ship field n ; Indicates the starboard rear feature point S of the ship's forward direction in the ship field b ;

[0047] Preferably, the basic parameters of the ship field dynamic model in S2 are obtained as follows:

[0048] Specifically, the ship establishes a virtual ship field dynamic model based on the dynamic information of other ships. The basic parameters of the ship field dynamic model are as follows:

[0049]

[0050] Where: L is the length of the ship; k AD k is the dimensionless ratio of the ship’s advance distance to the ship’s length; DT is the dimensionless ratio of the ship to the length; R fore The parameters used for the bow direction feature points in the ship field dynamic model; R aft The parameters used for the characteristic points in the stern direction in the ship field dynamic model; R starb The parameters used for the starboard feature point of the ship's forward direction in the ship field dynamic model; R port is the parameter used by the feature points on the port side of the ship in the ship field dynamic model; sd is the parameter used by the feature points on both sides of the ship in the ship field dynamic model;

[0051] The coordinates of each feature point in the ship field are calculated as:

[0052]

[0053] Where: F represents the most front feature point in the ship's forward direction; P f Indicates the port front feature point of the ship's forward direction in the ship field; P n Indicates the characteristic point perpendicular to the port side of the ship's forward direction in the ship field; P b Indicates the feature point on the port rear side of the ship's forward direction in the ship field; B indicates the most terminal feature point in the ship's forward direction in the ship field; S f Indicates the starboard front feature point of the ship's forward direction in the ship field; S n Indicates the characteristic point perpendicular to the starboard side of the ship's forward direction in the ship field; S b Indicates the feature point on the starboard rear side of the ship's forward direction in the ship field.

[0054] When ships meet, each feature point is used to determine the encounter situation and collision risk through the COLREGS-based collision risk assessment module, and to assist the ship collision avoidance navigation module in determining the collision avoidance navigation points.

[0055] Specifically, the coordinates of each feature point are determined in a relative geodetic coordinate system with the other ship's center as the origin, the other ship's bow as the positive y-axis, and the starboard direction perpendicular to the bow as the positive x-axis. Based on the basic parameters of the above ship domain dynamic model, each feature point is connected in sequence, and the ship domain dynamic model can be established. Fig.12 As shown, it is an irregular planar hexagon.

[0056] S3: A collision risk assessment module based on the International Regulations for Preventing Collisions at Sea (COLREGS) to obtain the judgment results of the encounter situation between the own ship and other ships;

[0057] Based on the collision risk assessment module of COLREGS, when another ship enters the radar detection or visual collision avoidance range, the encounter situation of the two ships is judged according to the established dynamic model of the ship field, and the collision avoidance responsibility of the ship is clarified.

[0058] Preferably, in S3, the method for obtaining the judgment result of the encounter situation between the own ship and other ships is as follows:

[0059] Based on the collision risk assessment module of COLREGS, when another ship enters the radar detection or visual collision avoidance range, the encounter situation of the two ships is judged according to the established dynamic model of the ship field, and the collision avoidance responsibility of the ship is clarified.

[0060] According to COLREGS regulations, the encounter situation of two ships is initially distinguished based on their relative positions. When another ship enters the collision avoidance range, in general, if the other ship appears on the port side of the ship, the ship has the main responsibility for collision avoidance; if the other ship appears on the starboard side of the ship, the ship can maintain the current course.

[0061] S31: When the other ship is ahead of our ship and in the opposite direction to our ship, that is, the difference between our ship and the other ship’s heading is within half a compass point (about 6°), if the following conditions are met:

[0062]

[0063] It is considered as a head-on collision situation, and the vessel is responsible for turning right to avoid the collision; otherwise, the vessel may maintain the original course and speed.

[0064] Where: α 1 is the current heading angle of the ship; α 2 is the current heading angle of the other ship;

[0065] S32: When own ship catches up with another ship in a direction greater than 22.5° behind the beam of the other ship's heading, the following conditions are met:

[0066]

[0067] When , the own ship overtakes the other ship from the port side of its forward direction, where: i is the unit vector in the x-axis direction;

[0068] Then, if

[0069]

[0070] It is determined to be a situation of overtaking on the port side, and the vessel is responsible for avoiding collision; otherwise, the vessel may maintain the original course and speed;

[0071] Among them, the directions of the own ship from the aft side, port side, starboard side, port front side, port center side, etc. of the other ship are recorded in the "International Regulations for Preventing Collisions at Sea, 1972". Technical personnel in the field can clearly determine the directions of the two ships, so no specific explanation is given here.

[0072] S33: When satisfied

[0073]

[0074] When this vessel overtakes the other vessel from the starboard side of its heading direction, if:

[0075]

[0076] It is determined to be a starboard side overtaking situation, and the vessel is responsible for avoiding collision; otherwise, the vessel may maintain the original course and speed;

[0077] S34: When own ship is located on the port front side of the other ship in the direction of travel and satisfies:

[0078]

[0079] When

[0080]

[0081] It is judged as a small-angle crossing situation, and the ship is responsible for avoiding collision; otherwise, the ship can maintain the original course and speed;

[0082] S35: When own ship is located on the port side of another ship in the direction of its progress and satisfies:

[0083]

[0084] , where j is the unit vector in the y direction;

[0085] like

[0086]

[0087] It is judged as a large-angle crossing situation, and the ship is responsible for avoiding collision; otherwise, the ship can maintain the original course and speed;

[0088] Specifically, in the collision risk assessment module, the collision risk is determined as D CPA The shortest possible distance in the ship's field is compared with that of the other ship in the corresponding encounter situation to determine the safety of the ship's collision avoidance action. CPA In the encounter situation where this ship is located, when the distance is not greater than the shortest possible distance in the ship area of ​​the other ship, this ship needs to execute the collision avoidance action issued by the ship collision avoidance navigation module to create a safe encounter environment for the other ship.

[0089] When D CPA In the encounter situation where this ship is in, when the distance between this ship and the other ship is greater than the shortest possible distance in the ship's field, this ship does not need to perform collision avoidance actions, but can continue sailing while maintaining the original course and speed.

[0090] Specifically, the method for determining the relative positions of the two ships is as follows:

[0091] x 2 -x 1 >0

[0092] If the conditions are met, the other ship is located on the right side of our ship; otherwise, it is located on the left side of our ship.

[0093] y 2 -y 1 >0

[0094] If the conditions are met, the other ship is in front of our ship; otherwise, it is behind our ship.

[0095] S4: According to the judgment result of the encounter situation between the own ship and other ships, and based on the ship collision avoidance navigation module of the International Regulations for Preventing Collisions at Sea COLREGS, the own ship is navigated to ensure the safety of the encounter navigation. Specifically, the collision risk assessment module based on COLREGS and the ship collision avoidance navigation module based on the International Regulations for Preventing Collisions at Sea COLREGS in this embodiment are both direct applications of the prior art, and therefore will not be described in detail.

[0096] The ship collision avoidance navigation module navigates the collision avoidance action of the ship according to the judgment result of the encounter situation and takes the ship field dynamic model of the other ship as a reference to ensure the safety of the encounter navigation.

[0097] Preferably, in S4, according to the judgment result of the encounter situation between the own ship and other ships, the method for navigating the own ship is as follows:

[0098] S40: When the own ship and the other ship are in a situation of encountering, execute S41; when the own ship and the other ship are in a situation of overtaking on the port side, execute S42; when the own ship and the other ship are in a situation of overtaking on the starboard side, execute S43; when the own ship and the other ship are in a situation of crossing at a small angle, execute S44; when the own ship and the other ship are in a situation of crossing at a large angle, execute S45;

[0099] S41: When this ship is in a situation of encounter with another ship, this ship shall first use the S f As the navigation point, the S f Switch to another ship's ship area S b As a new navigation point, the S b The collision avoidance action is deemed to be over and the vessel will return to the destination. Figure 2 As shown in the figure. The ship mentioned here is based on the S of the ship area of ​​the other ship. f The navigation point is the direction from the current position of the ship to the other ship's ship area. f Click to drive.

[0100] S42: Own ship is overtaking another ship on the port side if:

[0101]

[0102] The ship will maintain the original course and speed to sail towards the destination;

[0103] If satisfied:

[0104]

[0105] Then first use the P of the ship field of the other ship b The navigation point is the P in the ship area where the ship arrives at the other ship. b Switch to the ship area of ​​another ship f The new navigation point is the P of the ship that arrives in the area of ​​the other ship. f When , it is determined that the collision avoidance action is over and the vehicle is heading to the destination again. At this time, it is the port side overtaking situation 1. Figure 3 As shown;

[0106] If satisfied:

[0107]

[0108] Then first use B in the other ship's ship field as the navigation point, and when you reach B in the other ship's ship field, switch to S in the other ship's ship field. b As a new navigation point, the S b Switch to another ship's ship area S fAs a new navigation point, the S f When , it is determined that the collision avoidance action is over and the vehicle is heading to the destination again; at this time, it is the port side overtaking situation 2. Figure 4 As shown,

[0109] If satisfied:

[0110]

[0111] Then first use B in the other ship's ship field as the navigation point, and when you reach B in the other ship's ship field, switch to S in the other ship's ship field. b As a new navigation point, the S b When , it is determined that the collision avoidance action is over and the vehicle is heading to the destination again. At this time, it is the port side overtaking situation 3. Figure 5 As shown;

[0112] S43: Own ship is overtaking another ship on the starboard side if:

[0113]

[0114] Then the ship can maintain the original course and speed to reach the destination;

[0115] If satisfied:

[0116]

[0117] Then first use the S of the ship field of other ships b As the navigation point, the S b Switch to another ship's ship area S f As a new navigation point, the S f When the collision avoidance action is concluded, the vehicle will return to the destination;

[0118] If satisfied:

[0119]

[0120] Then first use B in the other ship's ship area as the navigation point, and when you reach B in the other ship's ship area, switch to P in the other ship's ship area. b The new navigation point is the P of the ship that arrives in the area of ​​the other ship. b Switch to the ship area of ​​another ship f The new navigation point is the P of the ship that arrives in the area of ​​the other ship. f When the collision avoidance action is concluded, the vehicle will return to the destination;

[0121] If satisfied:

[0122]

[0123] Then first use B in the other ship's ship area as the navigation point, and when you reach B in the other ship's ship area, switch to P in the other ship's ship area. b The new navigation point is the P of the ship that arrives in the area of ​​the other ship. b When the collision avoidance action is concluded, the vehicle will return to the destination;

[0124] S44: Own ship is in a small-angle crossing situation with another ship, if:

[0125]

[0126] Then first use the P of the ship field of the other ship f The navigation point is the P in the area of ​​the ship that arrives at the other ship. f Switch to another ship's ship area P b The new navigation point is the P of the ship that arrives in the area of ​​the other ship. b When the ship reaches B in the ship's field, the collision avoidance action is determined to be over and the ship will sail back to the destination. This is a small angle crossing situation 1. Figure 6 As shown;

[0127] Otherwise, first use the P of the other ship's ship area b The navigation point is the P in the area of ​​the ship that arrives at the other ship. b When the ship reaches B in the ship's field, the collision avoidance action is determined to be over and the ship will sail back to the destination. This is a small angle crossing situation 2. Figure 7 As shown;

[0128] S45: If own ship is in a situation of crossing another ship at a large angle, and is located in front of the other ship and satisfies:

[0129]

[0130] Then first use the P of the ship field of the other ship b The navigation point is the P in the area of ​​the ship that arrives at the other ship. b When the navigation point is reached, switch the navigation point B in the ship's field to the new navigation point. When the navigation point reaches the navigation point B in the ship's field, switch the navigation point S in the ship's field to the navigation point S. b As a new navigation point, the S b When , it is determined that the collision avoidance action is over and the vehicle is driven back to the destination; this is the large-angle intersection situation 1, such as Figure 8 As shown;

[0131] Otherwise, first use the P of the ship area of ​​the other ship b The navigation point is the P in the area of ​​the ship that arrives at the other ship. bWhen the ship reaches B in the ship's field, the collision avoidance action is determined to be over and the ship will sail back to the destination. This is a large-angle crossing situation 2. Fig. 9 As shown;

[0132] Where: j is the unit vector in the y-axis direction;

[0133] If the vessel is behind another vessel and satisfies:

[0134]

[0135] Then first use the other ship's ship area B as the navigation point, and when you reach the other ship's ship area B, switch to the other ship's ship area S b As a new navigation point, the S b When , the collision avoidance action is concluded and the vehicle is driven back to the destination; at this time, it is a large-angle intersection situation 3, such as Fig.10 As shown;

[0136] Otherwise, take B in the ship area of ​​the other ship as the navigation point. When reaching B in the ship area of ​​the other ship, the collision avoidance action is determined to be over and the ship will sail back to the destination. This is a large-angle crossing situation 4. Fig.11 shown.

[0137] An embodiment of the present invention is as follows:

[0138] Attached Figures 13-16 This is an embodiment of simulating the collision avoidance navigation method based on international maritime collision avoidance of the present invention using Unity. Fig.13 It shows that when the ship detects another ship while sailing on the original route, it uses the collision avoidance navigation method to establish a ship area centered on the other ship in real time, and judges the encounter situation according to the location and related conditions. At this time, the ship is in a small angle crossing situation and needs to bear the responsibility for collision avoidance. Fig.14 The P-shaped image of the ship in the ship area of ​​another ship is shown in the following instructions of the collision avoidance navigation module. b is the navigation point, deviating from the original route to P b Click and drive away. Fig.15 Shows the ship arriving at P b Then, according to the instructions of the collision avoidance navigation module, take point B in the ship's field as the navigation point and sail towards point B. Fig.16 It shows that when the ship arrives at point B, it ends the collision avoidance action under the instruction of the collision avoidance navigation module and sails towards the original destination.

[0139] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A collision avoidance navigation method based on the International Regulations for Preventing Collisions at Sea, It is characterized in that Includes the following steps: S1: When the other ship enters the radar range of our ship, obtain the current position coordinates of our ship, the current position coordinates of the other ship, the current speed of our ship, and the current speed of the other ship to obtain the minimum encounter time T CPA , minimum encounter distance D CPA , the dimensionless ratio k of the ship's advance distance to the ship's length AD , the dimensionless ratio k of the ship's initial turning diameter to its length DT ; S2: According to the current position coordinates of the own ship, the current position coordinates of the other ship, the current speed of the own ship, and the current speed of the other ship, the basic parameters of the dynamic model of the ship field are obtained, and the coordinates of the characteristic points of the ship field are calculated to establish the dynamic model of the ship field; The characteristic points of the ship field include: the frontmost characteristic point F indicating the forward direction of the ship in the ship field; The feature point P on the port front side indicating the ship's forward direction in the ship field f ; Indicates the feature point P perpendicular to the port side of the ship's forward direction in the ship field n ; Indicates the port rear feature point P of the ship's forward direction in the ship field b ; represents the most terminal feature point B in the ship's forward direction in the ship field; represents the starboard front feature point S in the ship's forward direction in the ship field f ; Indicates the characteristic point S perpendicular to the starboard side of the ship's forward direction in the ship field n ; Indicates the starboard rear feature point S of the ship's forward direction in the ship field b ; The coordinates of each feature point are determined by a relative geodetic coordinate system with the other ship's center as the origin, the other ship's bow as the positive direction of the y-axis, and the starboard direction perpendicular to the bow as the positive direction of the x-axis. According to the basic parameters of the ship field dynamic model, each feature point is connected in sequence, and the ship field dynamic model can be established, which is an irregular plane hexagon. S3: Collision risk assessment module based on COLREGS. When another ship enters the radar detection or visual collision avoidance range, the encounter situation between the two ships is judged according to the established ship field dynamic model. S4: Based on the judgment of the encounter situation between own ship and other ships and based on the ship collision avoidance navigation module of COLREGS, the international regulations for preventing collisions at sea, the own ship is navigated to ensure the safety of the encounter navigation.

2. A collision avoidance navigation method based on the International Regulations for Preventing Collisions at Sea according to claim 1, It is characterized in that In S1, the minimum encounter time T CPA , minimum encounter distance D CPA , the dimensionless ratio k of the ship's advance distance to the ship's length AD , the dimensionless ratio k of the ship's turning diameter to its length DT Get as follows: The distance between the two ships is obtained as: p 1 =(x 1 ,y 1 ) (1) p 2 =(x 2 ,y 2 ) (2) p 3 =p 1 -p 2 (3) Among them, p 1 is the current position coordinate of the ship, p 2 is the current position coordinate of the other ship, p 3 is the relative position vector of the two ships; x 1 is the horizontal coordinate of the current position of the ship; 1 is the ordinate of the current position of the ship; x 2 is the horizontal coordinate of the current position of the other ship; 2 is the ordinate of the current position of the other ship; Then T CPA and D CPA for: D CPA =|(p 1 +T CPA ·v 1 )-(p 2 +T CPA ·v 2 )| (5) Where, T CPA is the minimum encounter time, in seconds; D CPA is the minimum encounter distance, in meters; v 1 is the current speed of the ship, v 2 is the current speed of the other ship, in meters per second; k AD and k DT for: Where: V is the ship speed in knots; A D D is the ship's advance distance; T is the initial diameter of the turn; L is the length of the ship.

3. A collision avoidance navigation method based on the International Regulations for Preventing Collisions at Sea according to claim 2, It is characterized in that In S2, The basic parameters of the dynamic model of the ship field are obtained as follows: Where: L is the length of the ship; k AD k is the dimensionless ratio of the ship’s advance distance to the ship’s length; DT is the dimensionless ratio of the ship to the length; R fore The parameters used for the bow direction feature points in the ship field dynamic model; R aft The parameters used for the characteristic points in the stern direction in the ship field dynamic model; R starb The parameters used for the starboard feature point of the ship's forward direction in the ship field dynamic model; R port is the parameter used by the feature points on the port side of the ship in the ship field dynamic model; sd is the parameter used by the feature points on both sides of the ship in the ship field dynamic model; The coordinates of the characteristic points in the ship field are calculated as: Where: F represents the most front feature point in the ship's forward direction; P f Indicates the port front feature point of the ship's forward direction in the ship field; P n Indicates the characteristic point perpendicular to the port side of the ship's forward direction in the ship field; P b Indicates the feature point on the port rear side of the ship's forward direction in the ship field; B represents the most terminal characteristic point in the ship's forward direction in the ship field; S f Indicates the starboard front feature point of the ship's forward direction in the ship field; S n Indicates the characteristic point perpendicular to the starboard side of the ship's forward direction in the ship field; S b Indicates the feature point on the starboard rear side of the ship's forward direction in the ship field.

4. A collision avoidance navigation method based on the International Regulations for Preventing Collisions at Sea according to claim 3, It is characterized in that In S3, the method for obtaining the judgment result of the encounter situation between the own ship and other ships is as follows: S31: When another ship is ahead of our ship and heading in the opposite direction, if It is considered as an encounter situation; Where: α 1 is the current heading angle of the ship; α 2 is the current heading angle of the other ship; S32: When the own ship catches up with the other ship in a direction greater than the angle threshold from the right side of the other ship's forward direction, it is satisfied: When, where: i is the unit vector in the x-axis direction; like It is determined to be an overtaking situation on the port side; S33: When satisfied When: It is determined to be an overtaking situation on the starboard side; S34: When own ship is located on the port front side of the other ship in the direction of travel and satisfies: When It is determined to be a small-angle intersection situation; S35: When own ship is located on the port side of another ship in the direction of its progress and satisfies: , where j is the unit vector in the y direction; like It is determined to be a large-angle intersection situation.

5. A collision avoidance navigation method based on the International Regulations for Preventing Collisions at Sea according to claim 4, It is characterized in that In S4, according to the result of judging the encounter situation between the own ship and other ships, the method of navigating the own ship is as follows: S40: When the own ship and the other ship are in a situation of encountering, execute S41; when the own ship and the other ship are in a situation of overtaking on the port side, execute S42; when the own ship and the other ship are in a situation of overtaking on the starboard side, execute S43; when the own ship and the other ship are in a situation of crossing at a small angle, execute S44; when the own ship and the other ship are in a situation of crossing at a large angle, execute S45; S41: This ship first uses the S of the ship area of ​​the other ship f As the navigation point, the S f Switch to another ship's ship area S b As a new navigation point, the S b The collision avoidance action is judged to be over and the vessel will return to the destination; S42: If: The ship will maintain the original course and speed to sail towards the destination; If satisfied: Then first use the P of the ship field of the other ship b The navigation point is the P in the ship area where the ship arrives at the other ship. b Switch to another ship's ship area P f The new navigation point is the P of the ship that arrives in the area of ​​the other ship. f When the collision avoidance action is concluded, the vehicle will return to the destination; If satisfied: Then first use B in the other ship's ship field as the navigation point, and when you reach B in the other ship's ship field, switch to S in the other ship's ship field. b As a new navigation point, the S b Switch to another ship's ship area S f As a new navigation point, the S f When the collision avoidance action is concluded, the vehicle will return to the destination; If satisfied: Then first use B in the other ship's ship field as the navigation point, and when you reach B in the other ship's ship field, switch to S in the other ship's ship field. b As a new navigation point, the S b When the collision avoidance action is concluded, the vehicle will return to the destination; S43: If: Then the ship can maintain the original course and speed to reach the destination; If satisfied: Then first use the S of the ship field of other ships b As the navigation point, the S b Switch to another ship's ship area S f As a new navigation point, the S f When the collision avoidance action is concluded, the vehicle will return to the destination; If satisfied: First, use B in the ship domain of the other ship as the navigation point, and switch to P in the ship domain of the other ship when reaching B in the ship domain of the other ship. b As the new navigation point, when reaching P in the ship domain of the other ship b Switch to P in the ship domain of the other ship f As the new navigation point, when reaching P in the ship domain of the other ship f Determine that the collision avoidance action is over and head back to the destination. If satisfied: Then first use B in the other ship's ship area as the navigation point, and when you reach B in the other ship's ship area, switch to P in the other ship's ship area. b The new navigation point is the P of the ship that arrives in the area of ​​the other ship. b When the collision avoidance action is concluded, the vehicle will return to the destination; S44: If: Then first use the P of the ship field of the other ship f The navigation point is the P in the area of ​​the ship that arrives at the other ship. f Switch to the ship area of ​​another ship b The new navigation point is the P of the ship that arrives in the area of ​​the other ship. b When the collision avoidance action is completed, the ship will return to the destination. Otherwise, first use the P of the other ship's ship area b The navigation point is the P in the area of ​​the ship that arrives at the other ship. b When the collision avoidance action is completed, the ship will return to the destination. S45: If own ship is ahead of another ship and satisfies: Then first use the P of the ship field of the other ship b The navigation point is the P in the area of ​​the ship that arrives at the other ship. b When the navigation point is reached, switch the navigation point B in the ship's field to the new navigation point. When the navigation point reaches the navigation point B in the ship's field, switch the navigation point S in the ship's field to the navigation point S. b As a new navigation point, the S b When the collision avoidance action is concluded, the vehicle will return to the destination; Otherwise, first use the P of the ship area of ​​the other ship b The navigation point is the P in the area of ​​the ship that arrives at the other ship. b When the collision avoidance action is completed, the ship will return to the destination. Where: j is the unit vector in the y direction; If the vessel is behind another vessel and satisfies: Then first use the other ship's ship area B as the navigation point, and when you reach the other ship's ship area B, switch to the other ship's ship area S b As a new navigation point, the S b When the collision avoidance action is completed, the vehicle can be driven back to the destination; Otherwise, take B in the ship territory of the other ship as the navigation point, and when arriving at B in the ship territory of the other ship, determine that the collision avoidance action is completed and return to the destination.

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