CN115019561B - External collision risk early warning system of ship towing system under mutual-seeing condition - Google Patents

Abstract

The invention relates to an external collision risk early warning system of a ship towing system under mutual sight conditions. It includes an information collection module, an external collision risk detection module and a collision risk early warning quantification module; the external collision risk detection module is used to judge whether there is a collision between the towing system and other ships according to the ship field theory module and the nonlinear speed obstacle algorithm module Risk; the collision risk early warning quantification module includes a ship avoidance obligation identification module, other ship intention estimation module, other ship action quality assessment module, collision avoidance rule review module, other ship collision risk elimination capability quantification module and early warning level quantification module. The present invention can not only automatically detect whether there is a collision risk between other ships and any ship in the towing system, but also issue different levels of collision risk warnings to remind towing operators to take reasonable avoidance measures when there is a collision risk. To ensure the towing safety of the towing system.

Description

External Collision Risk Early Warning System for Ship Towing System in Mutual View

technical field

The invention relates to the technical field of towing, in particular to an external collision risk early warning system of a ship towing system under mutual sight.

Background technique

The towing operation of ships plays an important role in maritime transportation, and is increasingly used in various scenarios at sea. The towing operation of the ship is generally completed by the ship towing system. A common ship towing system consists of the front tugboat, the rear tugboat and the towed vessel and the cables connecting them. As shown in Figure 1, two tugboats and one towboat are composed tandem towing system. Compared with the single tugboat towing method, the tandem towing method includes two front and rear tugboats, which improves the controllability of the towing operation.

With the rapid development of maritime trade, more and more ships are used for transportation, and the possibility of collision between ships is greatly increased; at the same time, changeable weather, complex traffic conditions, and the maneuverability of the towing system itself are affected. These limits increase the risk of the ship's towing system colliding with other ships around.

In practice, when the towing operation is in progress, in order to avoid external collisions between the ships in the towing system and the surrounding ships of the towing system, other ships around the towing system are usually restricted from passing in the waters around the towing system. However, the traffic restriction strategy has the following disadvantages: first, the traffic restriction strategy relies too much on expert knowledge and cannot be automated; second, the restriction on the passage of ships around the towing system will reduce the utilization of the channel.

Contents of the invention

The present invention provides an external collision risk early warning system of a ship towing system under mutual sight, which can not only automatically detect whether there is a risk of collision between another ship and any ship in the towing system, but also issue different warnings when there is a risk of collision. Level collision risk warning, reminding towing operators to take reasonable avoidance measures to ensure the towing safety of the towing system.

In order to achieve the above-mentioned purpose, the present invention develops an external collision risk early warning system for a ship towing system under mutual sight, which is special in that it includes an information collection module, an external collision risk detection module, and a collision risk early warning quantification module;

The information collection module is used to collect the navigation trajectory of the towed ship, the basic information of the towed ship, the basic information of the front tugboat, the basic information of the rear tugboat, and the basic information and navigation information of other ships around the towing system in the towing system under environmental interference. to collect;

The external collision risk detection module is used to judge whether there is a collision risk between the towing system and other ships according to the ship field theory module and the nonlinear speed obstacle algorithm module;

The ship field theory module is used to determine whether there is a risk of collision according to whether the ship field of other ships overlaps with the ship field of the towed ship, or the front towboat, or the rear towboat within a period of observation time. If the ship area of the towed ship, or the front tow ship, or the rear tow ship does not intersect, then there is no risk of collision between the other ship and the towing system; If there is a risk of collision between the other ship and the towing system, the collision risk warning and quantification module will be activated;

The nonlinear speed obstacle algorithm module is used to obtain the speed vector set where the other ship collides with the towed system according to the position of the other ship and the trajectories of each ship in the towed system; if the actual speed of the other ship is outside the speed vector set, then There is no risk of collision between the other ship and the towed ship, or the front tugboat, or the rear tugboat; if the actual speed of the other ship is within the velocity vector set, there is a collision risk between the other ship and the towed ship, or the front tugboat, or the rear tugboat , the collision risk early warning quantification module is started;

The collision risk early warning quantification module includes a ship avoidance obligation identification module, other ship intention estimation module, other ship action quality evaluation module, collision avoidance rule review module, other ship collision risk elimination capability quantification module and early warning level quantification module;

The ship avoidance obligation identification module is used to determine whether the other ship is a give-way ship through the "International Rules for Avoiding Collisions at Sea", if the other ship is a give-way ship, then start the other ship's intention estimation module; if the other ship is not a give-way ship, there is a collision Risk, start the early warning level quantification module;

The other ship's intention estimation module is used to check whether the other ship takes evasive action to avoid collision, if the other ship takes evasive action, then start the other ship's action quality evaluation module; if the other ship does not take evasive action, start the other ship's collision risk Eliminate the capability quantification module;

The method for the other ship's intention estimation module to check whether the other ship has taken evasive action is as follows: if the other ship's intention index is 1, it means that the other ship takes evasive action; if the other ship's intention index is 0, it means that the other ship does not take evasive action; The other ship's intention indicator is expressed as:

in,

Int(t ₀ ) is the intention index of other ships at time t ₀ ,

V _Intr (t ₀ ) is the speed of other ship at time t ₀ ,

S _{NL_VO} (t ₀ ) is the speed at which the other ship collides with the towed ship, or the front tugboat, or the rear tugboat (b-2) at time t ₀ ,

表示空集，

represents the empty set,

∩ means intersection,

ΔC _Intr (t ₀ ) represents the route change of other ships at time t ₀ ;

The other ship's action quality evaluation module is used to judge whether the other ship's evasive action can effectively eliminate the risk of collision, and if the other ship's evasive action can effectively eliminate the collision risk, then start the collision avoidance rule review module; If the action cannot effectively eliminate the risk of collision, then start the warning level quantification module; the method for the other ship’s action quality evaluation module to judge whether the other ship’s evasive action can effectively eliminate the collision risk is if the other ship’s evasive action index is 1, then Indicates that the evasive action of other ships can effectively eliminate the risk of collision; if the evasive action index of other ships is 0, it means that the evasive actions of other ships cannot effectively eliminate the risk of collision; the evasive action index is expressed as:

in,

AQ(t ₀ ) is the evasive action index of other ships at time t ₀ ,

P _TS (x, y, t ₀ ) is the position of the towed ship, or the front tug ship, or the rear tug ship at time t ₀ , P _Intr (x, y, t ₀ ) is the position of other ships at time t ₀ ,

Dis(P _TS (x, y, t ₀ ), P _Intr (x, y, t ₀ )) is the distance between the other ship and the towed ship, or the front tugboat, or the rear tugboat at time t ₀ ,

minDisTS indicates the minimum distance at which the risk of collision can be eliminated by taking evasive action;

The collision avoidance rule review module is used to review whether the evasive actions of other ships violate the relevant provisions of the "International Regulations for Preventing Collisions at Sea". Start the early warning level quantification module;

The method for checking whether the evasive actions of other ships violate the "International Regulations for Preventing Collisions at Sea" by the review module of the rules for avoiding collisions is as follows. If it is 0, it means that other ships have violated the "International Regulations for Preventing Collisions at Sea"; the review result index is expressed as:

in,

Col is the review result index of the International Regulations for Preventing Collisions at Sea,

CPA means the nearest point of approach between the towed ship, or the front towed ship, or the rear towed ship and other ships,

RB _CPA indicates the relative position of other ships when they arrive at CPA;

The other ship's collision risk elimination capability quantification module is used to determine the other ship's ability to eliminate the collision risk according to the operational performance of the other ship, and start the risk level of the early warning level quantification module according to the level of the other ship's collision risk elimination ability;

The risk elimination ability in the other ship collision risk elimination ability quantification module is expressed as:

in,

L _AMM is the risk elimination capability of other ships,

AMM is the maneuverable margin of other ships,

AMM ₁ is the upper threshold value of other ships,

AMM ₂ is the lower threshold of other ships;

The early warning level quantification module is used to quantify the level of external collision risk and issue risk early warning;

The early warning level quantification module quantifies the external collision risk in three levels of "caution, warning, and alert", and the specific quantification standard is,

If the other ship is not a give-way ship, there is a risk of collision, and the level of collision risk is "alert";

If the other ship is a give way ship and takes evasive action, but the evasive action of the other ship cannot effectively eliminate the risk of collision, the collision risk level is "alert";

If the other ship is a give way ship and takes evasive action, and the evasive action of the other ship can effectively eliminate the risk of collision, but the evasive action of the other ship violates the action clauses of the International Regulations for Preventing Collisions at Sea, the collision risk level is "Warning";

If the other ship is a give-way ship and takes evasive action, and the evasive action of the other ship can effectively eliminate the risk of collision, and the evasive action of the other ship complies with the action clauses of the International Regulations for Preventing Collisions at Sea, the collision risk level is "Caution";

If the other ship is a give-way ship and no evasive action is taken, the collision risk level matching the other ship’s collision risk elimination ability is determined according to the quantification module of other ship’s collision risk elimination ability. The specific method is: if the other ship’s collision risk elimination ability is high, Then the collision risk level is "Caution", if the other ship's collision risk elimination ability is medium, the collision risk level is "Warning", if the other ship's collision risk elimination ability is low, the collision risk level is "Warning".

The advantages of the present invention are:

1. The present invention combines the theoretical module of the ship field and the nonlinear speed obstacle algorithm module, and considers the dynamics of the avoidance behavior. Coverage occurs within a period of observation to determine whether there is a risk of collision; on the other hand, whether there is a risk of collision is judged by whether the actual speed of other ships is within the speed vector set, thereby automatically detecting other ships and any ship in the towing system Whether there is a risk of collision between;

2. When it is determined that there is a risk of collision between the other ship and any ship in the towing system, the present invention determines whether the other ship is a give-way ship, whether the other ship takes evasive action, and whether the evasive action of the other ship can effectively eliminate Collision risk, other ship's evasive action violates the relevant avoidance action provisions of the International Regulations for Preventing Collisions at Sea, and other ship's ability to eliminate the risk of collision. Issue corresponding "caution, warning, alert" three levels of collision Risk warning, reminding towing operators to take reasonable avoidance measures to ensure the towing safety of the towing system.

The external collision risk warning system of the ship towing system in the mutual sight situation of the present invention can not only automatically detect whether there is a collision risk between other ships and any ship in the towing system; when there is a collision risk, it can issue different levels of collision risk Early warning, reminding the towing operators to take reasonable avoidance measures to ensure the safety of the towing system, without restricting the passage of ships around the towing system, and will not reduce the utilization rate of the channel.

Description of drawings

Fig. 1 is a schematic diagram of the composition of the ship towing system in the external collision risk warning system of the ship towing system in the case of mutual seeing in the present invention;

Figures 2a-2f are the state simulation diagrams when the towing system of the present invention meets other ship c-1 in the simulation experiment;

Fig. 3 is the relative distance between the towing system in Fig. 2a-2f and other ship c-1;

Fig. 4 is a change diagram of the collision risk level in the process of the towed system in Fig. 2a-2f encountering other ship c-1;

Figures 5a-5f are the state simulation diagrams when the towing system of the present invention meets other ship c-2 in the simulation experiment;

Fig. 6 is the relative distance between the towing system in Fig. 5a～5f and other ship c-2;

Fig. 7 is a change diagram of the collision risk level in the process of the towed system encountering other ship c-2 in Fig. 5a-5f;

FIG. 8 is a flow chart of the present invention for quantifying the risk level of external collision;

In the figure: the towed ship a, the front tugboat b-1, the rear tugboat b-2, the other ship c-1, and the other ship c-2.

detailed description

The present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments.

In the description of the present invention, it should be noted that the terms "length", "width", "upper", "lower", "front", "back", "left", "right", "vertical", The orientation or positional relationship indicated by "horizontal", "top", "bottom", "inner", "outer", etc. are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than Nothing indicating or implying that a referenced device or element must have a particular orientation, be constructed, and operate in a particular orientation should therefore not be construed as limiting the invention.

The external collision risk early warning system of the ship towing system in this mutual inspection situation includes an information collection module 1, an external collision risk detection module 2 and a collision risk early warning quantification module 3.

The information collection module 1 is used to analyze the navigation track of the towed ship a, the basic information of the towed ship a, the basic information of the front tugboat b-1, the basic information of the rear tugboat b-2 in the towing system through the AIS data, And the basic information and navigation information of other ships around the towing system are collected.

Among them, the navigation trajectory of the ship in the towing system under environmental interference is obtained by modeling, and the specific ship model parameters are shown in Table 1. In the towing system simulation, the basic information of the towed ship a, the front tugboat b-1, the rear tugboat b-2 and the other ship c are shown in Table 1.

Table 1 Basic information of the front tugboat, the rear tugboat, the towed boat and other ships

Other ship c-1, other ship c-2, front tugboat b-1, rear tugboat b-2 and towed ship a in Table 1 are based on “TitoNeri” 260, “TitoNeri” 260, “TitoNeri” 260, “TitoNeri” 260 and "CyberShip II" for modeling; the length of the tow cable is 1m, the maximum value of the thruster is 10N, the change rate of the drag angle between the front tugboat b-1 and the towboat a is not more than 5°/s, and the rear The change rate of the towing angle α ₂ (t) between the tugboat b-2 and the towboat a does not exceed 5°/s; the maximum towing force of the front tugboat b-1 is 3N, and the maximum towing force of the rear tugboat b-2 is 3N , the rate of change of traction force is less than 1N/s.

Using the scale models of the front tug b-1, the rear tug b-2 and the towed ship a in Table 1, the towing operation plan is given, as shown in Table 2.

Table 2 Design scheme of steering point traction operation under environmental interference

Table 2 shows the initial state and end state. The initial state includes the initial position and course of the front tugboat b-1, the rear tugboat b-2 and the towed ship a. Two turning points and one termination point are designed during the navigation.

The example assumes that the wind is constant, the relative wind speed is kept at 1 m/s, and the wind direction is 255°. In addition, towing operations were carried out in good visibility conditions.

The external collision risk detection module 2 is used to judge whether there is a collision risk between the towing system and other ships c according to the ship field theory module 2-1 and the nonlinear speed obstacle algorithm module 2-2;

The ship field theory module 2-1 is used to determine whether the ship field of the other ship c overlaps with the ship field of the towed ship a, or the front tugboat b-1, or the rear tugboat b-2 within a period of observation time. There is a risk of collision, if the ship domain of the other ship c does not intersect with the ship domain of the towed ship a, or the front tug ship b-1, or the rear tug ship b-2, then there is no collision risk between the other ship c and the towing system; if the other ship c The ship area of c intersects with the ship area of the towed ship a, or the front tow ship b-1, or the rear tow ship b-2, then there is a collision risk between the other ship c and the towing system, and the collision risk warning quantification module 3 is started.

The nonlinear speed obstacle algorithm module 2-2 is used to obtain the velocity vector set where the other ship c collides with the towing system according to the position of the other ship c and the trajectories of the ships in the towing system; if the actual speed of the other ship c is within outside the speed vector set, there is no risk of collision between the other ship c and the towed ship a, or the front tug ship b-1, or the rear tug ship b-2; if the actual speed of the other ship c is within the speed vector set, then the other ship c If there is a collision risk with the towed ship a, or the front tugboat b-1, or the rear tugboat b-2, the collision risk warning quantification module 3 is started.

The present invention combines the theoretical module 2-1 of the ship field and the non-linear speed obstacle algorithm module 2-2, and considers the dynamics of the avoidance behavior. The ship field of the tugboat is covered within a certain period of time to judge whether there is a risk of collision; on the other hand, whether there is a risk of collision is judged by whether the actual speed of the other ship is within the velocity vector set, so as to automatically detect the collision between the other ship and the towing system. Whether there is a risk of collision between any of the ships.

Specifically, the nonlinear speed obstacle algorithm module 2-2 obtains the velocity vector set at which the other ship c collides with the towing system through the following nonlinear speed obstacle algorithm formula,

in,

S _{NL_VO} (t ₀ ) is the speed at which other ship c collides with the towed ship a, or the front tugboat b-1, or the rear tugboat b-2 at time t ₀ ,

ConfP(O, R) is all possible positions where the other ship c collides with the towed ship a, or the front tugboat b-1, or the rear tugboat b-2,

P _TS (x, y, t) is the trajectory of the tugboat a, or the front tugboat b-1, or the rear tugboat b-2 at time t,

P _Intr (x, y, t ₀ ) is the position of his ship c at time t ₀ ,

R represents the size of the ship's field.

⊕ represents the Kowski addition operation.

Specifically, for the external collision risk detection module 2, if there is a collision risk between the other ship c and the towed ship a, or the front tugboat b-1, or the rear tugboat b-2, that is, the collision risk index is 1; if the other ship c There is no collision risk with the towed ship a, or the front tugboat b-1, or the rear tugboat b-2, that is, the collision risk index is 0; the collision risk index is expressed as:

in,

IC(t ₀ ) is the collision risk index at time t ₀ ,

V _Intr (t ₀ ) is the speed of other ship c at time t ₀ ,

S _{NL_VO} (t ₀ ) is the speed at which other ship c collides with the towed ship a, or the front tugboat b-1, or the rear tugboat b-2 at time t ₀ ,

表示空集，

represents the empty set,

∩ means intersection.

The collision risk early warning quantification module 3 includes a ship avoidance obligation identification module 3-1, other ship intention estimation module 3-2, other ship action quality evaluation module 3-3, collision avoidance rule review module 3-4, other ship collision risk Eliminate capacity quantification modules 3-5 and early warning level quantification modules 3-6.

Said ship avoidance obligation identification module 3-1 is used to determine whether other ship c is a give-way ship through the "International Regulations for Preventing Collisions at Sea", and if other ship c is a give-way ship, start the other ship's intention estimation module 3-2; If ship c is not a give-way ship, there is a risk of collision, and the early warning level quantification module 3-6 is activated.

The other ship's intention estimation module 3-2 is used to check whether the other ship c takes evasive actions to avoid collisions, if the other ship c takes evasive actions, then start the other ship's action quality assessment module 3-3; if the other ship c does not take evasive actions If the evasive action is taken, start the other ship collision risk elimination capability quantification module 3-5.

The other ship's action quality assessment module 3-3 is used to judge whether the avoidance action of other ship c can effectively eliminate the risk of collision, and if the avoidance action of other ship c can effectively eliminate the risk of collision, then start the collision avoidance rule review module 3 -4; If the evasive action of other ship c cannot effectively eliminate the risk of collision, start the warning level quantification module 3-6.

The collision avoidance rule review module 3-4 is used to review whether the evasive action of other ship c violates the relevant provisions of the International Regulations for Preventing Collisions at Sea, regardless of whether the evasive action of other ship c violates the relevant provisions of the International Regulations for Preventing Collisions at Sea. For avoidance action clauses, the early warning level quantification modules 3-6 are activated.

The other ship collision risk elimination capability quantification module 3-5 is used to determine the collision risk elimination ability of the other ship c according to the operational performance of the other ship c, and start the early warning level quantification module 3 according to the level of the collision risk elimination ability of the other ship c -6 risk level.

The warning level quantification module 3-6 is used to quantify the level of the external collision risk and issue a risk warning.

Specifically, the other ship's intention estimation module 3-2 checks whether the other ship c takes evasive action. If the other ship's intention index is 1, it means that the other ship c takes evasive action; if the other ship's intention index is 0, then Indicates that other ship c has not taken evasive action; the other ship's intention indicator is expressed as:

in,

Int(t ₀ ) is the other ship's intention index at time t ₀ ;

V _Intr (t ₀ ) is the speed of other ship c at time t ₀ ,

S _{NL_VO} (t ₀ ) is the speed at which other ship c collides with the towed ship a, or the front tugboat b-1, or the rear tugboat b-2 at time t ₀ ,

表示空集，

represents the empty set,

∩ means intersection,

ΔC _Intr (t ₀ ) represents the route change amount of other ship c at time t ₀ .

Specifically, the other ship's action quality evaluation module 3-3 judges whether the evasive action of the other ship c can effectively eliminate the risk of collision. If the evasive action index of the other ship c is 1, it means that the evasive action of the other ship c can effectively eliminate the risk of collision; if the evasive action index of other ship c is 0, it means that the evasive action of other ship c cannot effectively eliminate the risk of collision; the evasive action index is expressed as:

in,

AQ(t ₀ ) is the evasive action index of other ship c at time t ₀ ;

P _TS (x, y, t ₀ ) is the position of the tugboat a, or the front tugboat b-1, or the rear tugboat b-2 at time _t0 ;

P _Intr (x, y, t ₀ ) is the position of other ship c at time t ₀ ;

Dis(P _TS (x, y, t ₀ ), P _Intr (x, y, t ₀ )) is the relationship between the other ship c and the towed ship a, or the front tugboat b-1, or the rear tugboat b-2 at time t ₀ the distance between

minDisTS represents the minimum distance at which the risk of collision can be eliminated by taking evasive action.

Specifically, the inspection module 3-4 of the rules for avoiding collisions checks whether the evasive action of other ship c violates the "International Rules for Preventing Collisions at Sea". Rules for Preventing Collisions at Sea; if the review result index is 0, it means that other ship c violated the International Regulations for Preventing Collisions at Sea; the review result index is expressed as:

in,

Col is the review result index of the International Regulations for Preventing Collisions at Sea,

CPA means the nearest point of approach that is guaranteed to be reached by the tugboat a, or the front tugboat b-1, or the rear tugboat b-2, and other ship c,

RB _CPA indicates the relative position of other ship c when it arrives at CPA.

Specifically, the risk elimination capability in the other ship collision risk elimination capability quantification module 3-5 is expressed as:

in,

L _AMM is the risk elimination capability of other ship c,

AMM is the maneuverable margin of other ship c,

AMM ₁ is the upper threshold value of other ship c,

AMM ₂ is the lower limit of the threshold of other ship c.

If other ship c is a small freighter, AMM ₁ is 0.9, and AMM ₂ is 0.4.

Specifically, the warning level quantification module 3-6 quantifies the external collision risk in three levels of "Caution, Warning, Warning", wherein "Caution" indicates that the collision risk has already occurred, and at this time, the towing system as a direct sailing ship does not allow Take any evasive action, but watch for changes in the current collision situation. "Warning" means that the towing system as a direct vessel allows evasive action to deconflict, because an emergency situation will develop if no action is taken. "Alarm" means that when the towing system is used as a give-way ship or a direct ship, reasonable avoidance actions should be taken to avoid collisions.

The specific quantitative standard is,

If the other ship c is not a give-way ship, there is a risk of collision, and the level of the risk of collision is "alert";

If the other ship c is a give-way ship and takes evasive action (Int(t ₀ )=1), but the evasive action of other ship c cannot effectively eliminate the collision risk (AQ=0), the collision risk level is "alert";

If the other ship is a give-way ship and takes evasive action (Int(t ₀ )=1), and the evasive action of other ship c can effectively eliminate the risk of collision (AQ=1), but the evasive action of other ship c violates the International Maritime Collision Avoidance Rules" Action Clause (Col=0), the collision risk level is "Warning";

If the other ship is a give-way ship and takes evasive action (Int(t ₀ )=1), and the evasive action of other ship c can effectively eliminate the risk of collision (AQ=1), and the evasive action of other ship c complies with the International Maritime Collision Avoidance Rules" action clause (Col=1), the collision risk level is "Caution";

If the other ship is a give-way ship and no evasive action is taken (Int(t ₀ )=0), then according to the quantification module 3-5 of other ship’s collision risk elimination ability, determine the collision risk level that matches the collision risk elimination ability of other ship c, The specific method is: if other ship c has a high ability to eliminate collision risk ( _LAMM = H), then the collision risk level is "Caution", and if other ship c has a medium ability to eliminate collision risk ( _LAMM = M), then the collision risk level is "Warning", if other ship c's collision risk elimination ability is low ( _LAMM =L), the collision risk level is "Warning".

Refer to FIG. 8 for the flow chart of the present invention for quantifying the risk level of external collision.

The following case analysis.

Case 1, see Figures 2a-2f. Figures 2a-2f show the position, course and warning level information of the six sampling times when the towing system encounters other ship c-1.

Figure 2a shows the encounter scene at t=1s, IC=1, then there is a collision risk, but Int=0, then the other ship c-1 has not taken evasive action, then, according to the fifth risk level quantification standard above, when When L _AMM =H, that is, other ship c-1 has a high ability to eliminate the collision risk, and the collision risk level is "Caution", as shown in Fig. 4 . In the next 100s, the other ship c-1 is still sailing in a straight line at a constant speed and constantly approaching the towing system, as shown in Figure 3.

Figure 2b shows the encounter scene at t=100s, IC=1, there is a risk of collision, Int=0, the other ship c-1 has not taken evasive action, when _LAMM =M, that is, the other ship c-1 collided If the risk elimination ability is moderate, then according to the fifth risk level quantification standard above, the collision risk level is "Warning", see Figure 4. At this time, the towing system is allowed to take evasive maneuvers to ensure safe passage.

Figure 2c is the encounter scene at t=120s, IC=1, there is a risk of collision, Int=1, the other ship c-1 takes evasive action, but AQ=0, the effect of the evasive maneuver adopted by the other ship c-1 Poor, that is, the evasive action of other ship c-1 cannot effectively eliminate the risk of collision, then, according to the second risk level quantification standard above, the level of collision risk is “warning”, see Figure 4.

Figure 2d is the encounter scene at t=150s, IC=1, there is a risk of collision, Int=1, the other ship c-1 takes evasive action, but AQ=0, that is, the evasive action of other ship c cannot effectively If the collision risk is eliminated, then, according to the above-mentioned second risk level quantification standard, the collision risk level is "warning", as shown in Figure 4.

Figure 2e shows the encounter scene at t=240s, IC=1, then there is a collision risk, but Int=0, then the other ship c-1 has not taken evasive action, then, according to the fifth risk level quantification standard above, when When L _AMM =L, that is, other ship c-1 has a low collision risk elimination capability, and the collision risk level is "warning", see Figure 4. At this time, the distance between the other ship c-1 and the towed ship a, or the front tug ship b-1, or the rear tug ship b-2 is reduced to the minimum value, as shown in Figure 3, the ship area of the other ship c-1 and The towed ship a, or the front tugboat b-1, or the rear tugboat b-2 overlapped in the ship field.

Figure 2f shows the encounter scene at t=300s, IC=1, then there is a collision risk, but Int=0, then the other ship c-1 has not taken evasive action, then, according to the fifth risk level quantification standard above, when When L _AMM =L, that is, other ship c-1 has a low collision risk elimination capability, and the collision risk level is "warning", see Figure 4.

It can be seen from Fig. 2a-2f that when the ship in the towing system encounters other ship c-1, the risk of collision exists throughout the encounter process. Due to the poor maneuvering efficiency of the other ship c-1, the towing system and other ship c-1 There was a dangerous close encounter between c-1s.

In the above case 1, the changes of detection and early warning parameters of the towing system over time are shown in Table 3.

Table 3 Changes of various detection and early warning parameters of the towing system over time

Time: s IC Int AQ Col L_AMM CAL 10 1 0 / / 0.9143 Be careful 20 1 0 / / 0.9143 Be careful 30 1 0 / / 0.9143 Be careful 40 1 0 / / 0.9143 Be careful 50 1 0 / / 0.9143 Be careful 60 1 0 / / 0.9143 Be careful 70 1 0 / / 0.9143 Be careful 80 1 0 / / 0.9 warn 90 1 0 / / 0.8857 warn 100 1 0 / / 0.7286 warn 110 1 1 0 / / alarm 120 1 1 0 / / alarm 130 1 1 0 / / alarm 140 1 1 0 / / alarm 150 1 1 0 / / alarm 160 1 1 0 / / alarm 170 1 0 / / 0 alarm 180 1 0 / / 0 alarm 190 1 0 / / 0 alarm 200 1 0 / / 0 alarm 210 1 0 / / 0 alarm 220 1 0 / / 0 alarm 230 1 0 / / 0 alarm 240 1 0 / / 0 alarm 250 1 0 / / 0 alarm 260 1 0 / / 0 alarm 270 1 0 / / 0 alarm 280 1 0 / / 0 alarm 290 1 0 / / 0 alarm 300 1 0 / / 0 alarm

Case 2 is the cross-meeting situation between the ship's towing system and other ship c-2, and the towing system is in the direct sailing position. The collision risk is generated from the beginning moment, and the collision risk between the two is eliminated in 470 seconds due to the effective avoidance action taken by the other ship c-2 (Fig. 7). Figures 5a-5f show the position, heading and warning level information of the six sampling times when the towed system encounters other ship c-2.

At 300 seconds, the towing system is in danger of colliding with other ships. Because the other ship c-2 did not take collision avoidance actions to avoid collision (Int(t ₀ )=0), but its risk elimination ability is very high at this time L _AMM =H, so the warning level is marked as "Caution" (see Fig. 5a). Before 380 seconds, the other ship c-2 kept approaching this towed system with a constant speed and heading (see Figure 6). At 340 seconds, the risk of collision still exists, and the risk elimination ability of other ship c-2 decreases, but it is still at a relatively high level L _AMM =H, so the warning level is "Caution" (see Fig. 5b). At 370 seconds, there is a risk of collision, but the risk elimination capability of the other ship c-2 drops to a medium level L _AMM =M, so the warning level is marked as "Warning" (see Figure 5c). From 390 seconds to 520 seconds, his ship C-2 turned to starboard to avoid collision. Through action quality evaluation and COLREGs review, it is judged that the collision avoidance action adopted by other ship c-2 is effective and complies with COLREGs. At 420 seconds, the distance between other vessel c-2 and the towed vessel was reduced to about 19 meters (Fig. 6). Considering that the collision can be eliminated only by the collision avoidance actions adopted by the other ship c-2, the warning level is lowered to "caution" (see Figure 5d). Because the other ship c-2 has taken effective collision avoidance actions, the collision risk was eliminated at 470 seconds, see Fig.7. The tow system and the other ship c-2 have been close until 590 seconds. At 590 seconds, the other ship c-2 and the towed ship reached the closest point of approach (CPA), and their distance was reduced to a minimum value of 7.38m (Figure 6), which is a safe distance. After 590 seconds, the distance between them keeps increasing.

Table 4 shows the changes of detection and early warning parameters of the towing system over time in Case 2 above.

Table 4 Changes of various detection and early warning parameters of the towing system over time

The external collision risk warning system of the ship towing system in the mutual sight situation of the present invention can not only automatically detect whether there is a collision risk between other ships and any ship in the towing system, but also issue different levels of collision risk when there is a collision risk Early warning, reminding the towing operators to take reasonable avoidance measures to ensure the safety of the towing system, without restricting the passage of ships around the towing system, and will not reduce the utilization rate of the channel.

The above-mentioned embodiment is a preferred embodiment of the present invention, but the embodiment of the present invention is not limited by the above-mentioned embodiment, and any other changes, modifications, substitutions, combinations, Simplification should be equivalent replacement methods, and all are included in the protection scope of the present invention.

Claims (4)

1. An external collision risk early warning system of a ship towing system under mutual sight, characterized in that: comprising an information collection module (1), an external collision risk detection module (2) and a collision risk early warning quantification module (3); The information collection module (1) is used for the towed ship (a) navigation track, the basic information of the towed ship (a), the basic information of the front tugboat (b-1), the basic information of the rear tugboat (b-1) in the towing system under the environment interference. -2) Collect the basic information of the ship, and other ships around the towing system (c) basic information and navigation information; The external collision risk detection module (2) is used to judge whether there is a collision risk between the towing system and other ships (c) according to the ship field theory module (2-1) and the nonlinear speed obstacle algorithm module (2-2); The ship field theory module (2-1) is used to determine whether the ship field of the other ship (c) is related to the ship field of the towed ship (a), or the front tow ship (b-1), or the rear tow ship (b-2) Coverage occurs within a period of observation time to determine whether there is a risk of collision, if the ship area of the other ship (c) is in contact with the ship area of the towed ship (a), or the front tugboat (b-1), or the rear tugboat (b-2) do not intersect, then there is no risk of collision between the other ship (c) and the towed system; If there is a collision risk between the other ship (c) and the towing system, the collision risk early warning quantification module (3) is started; The nonlinear speed obstacle algorithm module (2-2) is used to obtain the velocity vector set where the other ship (c) collides with the towed system according to the position of the other ship (c) and the trajectories of each ship in the towed system; if If the actual speed of the other ship (c) is outside the velocity vector set, there is no risk of collision between the other ship (c) and the towed ship (a), or the front tugboat (b-1), or the rear tugboat (b-2); If the actual speed of the other ship (c) is within the velocity vector set, there is a risk of collision between the other ship (c) and the towed ship (a), or the front tugboat (b-1), or the rear tugboat (b-2), Then start the collision risk early warning quantification module (3); The collision risk early warning quantification module (3) includes a ship avoidance obligation identification module (3-1), other ship's intention estimation module (3-2), other ship's action quality evaluation module (3-3), and a collision avoidance rule review module (3-4), other ship collision risk elimination capability quantification module (3-5) and early warning level quantification module (3-6); The ship avoidance obligation identification module (3-1) is used to determine whether the other ship (c) is a give-way ship through the "International Regulations for Preventing Collisions at Sea", and if the other ship (c) is a give-way ship, then start the other ship's intention estimation module (3-2); if the other ship (c) is not a give-way ship, there is a risk of collision, start the warning level quantification module (3-6); The other ship's intention estimation module (3-2) is used to check whether the other ship (c) takes evasive actions to avoid collisions, and if the other ship (c) takes evasive actions, then starts the other ship's action quality assessment module (3-3 ); if the other ship (c) does not take evasive action, start the other ship collision risk elimination capability quantification module (3-5); The other ship's intention estimation module (3-2) checks whether the other ship (c) takes evasive action. If the other ship's intention index is 1, it means that the other ship (c) takes evasive action; if the other ship's intention index is 0, it means that the other ship (c) has not taken evasive action; the other ship’s intention index is expressed as:

in, Int(t ₀ ) is the intention index of other ships at time t ₀ , V _Intr (t ₀ ) is the speed of other ship (c) at time t ₀ , S _{NL_VO} (t ₀ ) is the speed at which the other ship (c) collides with the towed ship (a), or the front tugboat (b-1), or the rear tugboat (b-2) at time t ₀ ,

represents the empty set, ∩ means intersection, ΔC _Intr (t ₀ ) represents the route change of the other ship (c) at time t ₀ ; The other ship's action quality assessment module (3-3) is used to judge whether the evasive action of the other ship (c) can effectively eliminate the risk of collision, and if the evasive action of the other ship (c) can effectively eliminate the risk of collision, start Collision avoidance rule review module (3-4); if the evasive action of other ship (c) cannot effectively eliminate the risk of collision, then start the warning level quantification module (3-6); said other ship action quality evaluation module (3- 3) The method of judging whether the evasive action of other ship (c) can effectively eliminate the risk of collision is as follows: If the evasive action index of other ship (c) is 1, it means that the evasive action of other ship (c) can effectively eliminate the risk of collision ; If the evasive action index of other ship (c) is 0, it means that the evasive action of other ship (c) cannot effectively eliminate the risk of collision; the evasive action index is expressed as:

in, AQ(t ₀ ) is the evasive action index of other ship (c) at time t ₀ , P _TS (x, y, t ₀ ) is the position of the tugboat (a), or the front tugboat (b-1), or the rear tugboat (b-2) at time _t0 , P _Intr (x, y, t ₀ ) is the position of his ship (c) at time t ₀ , Dis(P _TS (x, y, t ₀ ), P _Intr ( _x , y, t ₀ )) is the other ship (c) and the towed ship (a), or the front tug ship (b-1), or distance between rear tugs (b-2), minDisTS indicates the minimum distance at which the risk of collision can be eliminated by taking evasive action; The collision avoidance rule review module (3-4) is used to review whether the evasive action of other ship (c) violates the relevant avoidance action provisions of the "International Regulations for Preventing Collisions at Sea", regardless of whether the evasive action of other ship (c) violates the "International Regulations for Preventing Collisions at Sea". The relevant avoidance action clauses of the Rules for Preventing Collisions at Sea have activated the warning level quantification module (3-6); The inspection module (3-4) of the rules for avoiding collisions checks whether the evasive actions of other ships (c) violate the "International Regulations for Preventing Collisions at Sea". International Regulations for Preventing Collisions at Sea; if the review result indicator is 0, it means that other ship (c) violated the International Regulations for Preventing Collisions at Sea; the review result indicators are expressed as:

in, Col is the review result index of the International Regulations for Preventing Collisions at Sea, CPA means the nearest point of approach guaranteed to be reached by the towed vessel (a), or the leading towing vessel (b-1), or the aft towing vessel (b-2) and another vessel (c), RB _CPA indicates the relative bearing of the other ship (c) when it arrives at CPA; The other ship collision risk elimination capability quantification module (3-5) is used to determine the ability of the other ship (c) to eliminate the collision risk according to the operational performance of the other ship (c), and according to the ability of the other ship (c) to eliminate the collision risk High and low, start the risk level of the early warning level quantification module (3-6); The risk elimination capability in the other ship collision risk elimination capability quantification module (3-5) is expressed as:

in, L _AMM is the risk elimination capability possessed by other ships (c), AMM is the maneuverable margin possessed by other ships (c), AMM ₁ is the upper threshold value possessed by other ship (c), AMM ₂ is the lower threshold of other ship (c); The early warning level quantification module (3-6) is used to quantify the level of external collision risk and issue risk early warning; The early warning level quantification module (3-6) quantifies the external collision risk in three levels of "caution, warning, and alert", and the specific quantification standard is, If the other ship (c) is not a give-way ship, there is a risk of collision, and the level of risk of collision is "alert"; If the other ship (c) is a give-way ship and takes evasive action, but the evasive action of other ship (c) cannot effectively eliminate the risk of collision, the collision risk level is "alert"; If the other ship is a give way ship and takes evasive action, and the evasive action of the other ship (c) can effectively eliminate the risk of collision, but the evasive action of the other ship (c) violates the action clause of the International Regulations for Preventing Collisions at Sea, then the collision risk The level is "warning"; If the other ship is a give-way ship and takes evasive action, and the evasive action of the other ship (c) can effectively eliminate the risk of collision, and the evasive action of the other ship (c) complies with the action clauses of the International Regulations for Preventing Collisions at Sea, then the collision risk Level is "Caution"; If the other ship is a give-way ship and no evasive action is taken, the collision risk level matching the collision risk elimination ability of the other ship (c) is determined according to the quantification module (3-5) of the collision risk elimination ability of the other ship. The specific method is: if The collision risk elimination ability of other ship (c) is high, and the collision risk level is "Caution". If the collision risk elimination ability of other ship (c) is medium, the collision risk level is "Warning". If the capability is low, the collision risk level is "Alert". 2. The external collision risk early warning system of the ship towing system under mutual sight according to claim 1, characterized in that: the nonlinear speed obstacle algorithm module (2-2) obtains the other ship by the following nonlinear speed obstacle algorithm formula (c) the set of velocity vectors at which the collision with the towed system occurs,

in, S _{NL_VO} (t ₀ ) is the speed at which the other ship (c) collides with the towed ship (a), or the front tugboat (b-1), or the rear tugboat (b-2) at time t ₀ , ConfP(O, R) is all possible positions where the other ship (c) collides with the towed ship (a), or the front tugboat (b-1), or the rear tugboat (b-2), P _TS (x, y, t) is the position of the tugboat (a), or the front tugboat (b-1), or the rear tugboat (b-2) at time t, P _Intr (x, y, t ₀ ) is the position of his ship (c) at time t ₀ , R represents the size of the ship's field, ⊕ represents the Kowski addition operation. 3. The external collision risk early warning system of the ship towing system under mutual sight according to claim 2, characterized in that: for the external collision risk detection module (2), if the other ship (c) and the towed ship (a), or There is a collision risk between the front tugboat (b-1) or the rear tugboat (b-2), that is, the collision risk index is 1; if the other ship (c) and the towed boat (a) or the front tugboat (b-1) , or there is no collision risk between the rear tugboats (b-2), that is, the collision risk index is 0; the collision risk index is expressed as:

in, IC(t ₀ ) is the collision risk index at time t ₀ , V _Intr (t ₀ ) is the speed of other ship (c) at time t ₀ , S _{NL_VO} (t ₀ ) is the speed at which the other ship (c) collides with the towed ship (a), or the front tugboat (b-1), or the rear tugboat (b-2) at time t ₀ ,

represents the empty set, ∩ means intersection. 4. The external collision risk warning system of the ship towing system under mutual sight according to claim 1, characterized in that: if the other ship (c) is a small cargo ship, then AMM ₁ is 0.9, and AMM ₂ is 0.4.

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