JP7364521B2 - Avoidance route search device, avoidance route search method, program - Google Patents

Description

Application of Article 30, Paragraph 2 of the Patent Act (1) Publication date November 30, 2019 Publication Koden Seisakusho Co., Ltd. Koden Technical Report No. 35

The present invention relates to an avoidance route search device, an avoidance route search support device, an avoidance route search method, an avoidance route search support method, and a program for preventing collisions during navigation of ships.

Generally speaking, if your own ship is navigating toward a destination and crosses another ship, if you feel a ``fear of collision'' according to the Maritime Collision Prevention Act, and if your own ship is a give-way vessel, you will be significantly affected. Turn around and pass the stern of another vessel at a safe distance, and then return to the original route after moving far enough away.

Furthermore, methods for determining dangerous areas in relation to other ships have also been proposed, such as the technique disclosed in Patent Document 1. The technology shown in Patent Document 1 is a method that draws a DCPA (Distance of Closest Point of Approach) circle around the own ship and prevents the DCPA circle around the own ship from coming into contact with other ships in the future. be.

Japanese Patent Application Publication No. 07-246998

However, the conventional technology does not assume multiple other ships, so even if the risk of collision between one's own ship and each other ship can be predicted, the risk of collision between one ship and another ship after avoiding one other ship is It was difficult to predict the risk of a collision. Therefore, it was difficult to decide on a route in an area where there were multiple other ships. Furthermore, in the prior art, when the own ship sails in front of another ship, the route is determined so as not to contact the DCPA circle even after passing in front of the other ship. However, if your own ship passes in front of another ship without touching the DCPA circle, there is no risk of collision even if the other ship touches the DCPA circle. Furthermore, when the own ship is sailing behind another ship whose sailing direction is different by about 90 degrees, the ship selects a route so as not to come into contact with the DCPA circle even before passing behind the other ship. However, if the sailing directions of another ship and your own ship differ by about 90 degrees, even if the other ship temporarily contacts the DCPA circle, the ship should not contact the DCPA circle when passing directly behind the other ship. There is no risk of collision if the ship sails. In other words, according to the prior art, the route was determined with too much leeway. In this way, it was difficult to search for a route in an area where there were multiple other ships because the route was determined with too much leeway and without considering multiple other ships. This was also a hindrance to realizing automatic navigation for ships.

Therefore, an object of the present invention is to facilitate route searching in a sea area where a plurality of other ships exist. A first means for facilitating route searching is to provide a route searching method that assumes the presence of a plurality of other ships. The second method is to appropriately set areas to be avoided. By using either method alone, it is possible to facilitate route searching in areas where there are multiple other ships, and by combining both methods, route searching can be made even easier.

A first aspect of the present invention aims to provide a technology that can search for a route even in a sea area where a plurality of other ships exist. The second invention aims to provide a technique for appropriately setting areas to be avoided.

The avoidance route search device according to the first invention includes an information collection section, a condition setting section, a predicted avoidance area calculation section, a route search section, and a repetition control section. The information collection unit collects information on the position and speed of the own ship and other ships in the vicinity. The condition setting section sets conditions for the position and speed of the own ship and other ships. The predicted avoidance area calculation unit calculates a predicted avoidance area, which is an area that satisfies predetermined avoidance area conditions, for each other ship based on the positions and speeds of the own ship and other ships set by the condition setting unit. If there is any predicted avoidance area on a straight line connecting the predetermined destination and the own ship set by the condition setting unit, the route search unit determines the boundary of the predicted avoidance area that satisfies the predetermined route search conditions. Search for route point candidates from points on the line. For each route point candidate, the repeat control unit sets one of the points on the boundary line of the predicted avoidance area to which the route point candidate belongs as the position of the own ship proceeding in the direction of the destination, and determines whether the own ship will reach the position. The condition setting section is instructed to set the position of the other ship from the time when the condition setting section, the predicted avoidance area calculation section, and the route search section repeat the processing.

The avoidance route search support device, which is the second invention, includes an information gathering section and a predicted avoidance area calculation section. The distance to avoid another ship in the forward direction is the forward safety distance, the distance to avoid the other ship in the side direction is the side safety distance, and the distance to avoid the other ship in the rear direction is the rear safety distance. The information collection unit collects information on the position and speed of the own ship and other ships in the vicinity. The predicted avoidance area calculation unit secures a forward safe distance when the own ship is located in front of another ship, secures a side safety distance when the own ship is located directly beside the other ship, and secures a lateral safe distance when the own ship is located directly beside the other ship. Calculates the predicted avoidance area to ensure a safe rear distance when positioned directly behind the ship.

According to the avoidance route search device of the present invention, since the processing of the condition setting section, the predicted avoidance area calculation section, and the route search section are repeated, a route can be searched even in an ocean area where a plurality of other ships exist. According to the avoidance route search support device of the present invention, a forward safe distance is secured when the own ship is located in front of another ship, and a lateral safe distance is secured when the own ship is located directly beside the other ship. , since a safe rear distance is ensured when the own ship is located directly behind another ship, areas to be avoided can be appropriately set.

FIG. 2 is a diagram showing an example of a functional configuration of an avoidance route search device. The figure which shows the example of a processing flow of an avoidance route search device. The figure which shows the image of the predicted avoidance area calculated|required using the DCPA circle. A diagram showing the concept of the proposed safety distance. A diagram showing an image of a predicted avoidance area when the other ship is slower than the own ship and when the other ship is at the same speed. The figure which shows the 1st image of the predicted avoidance area when another ship is faster than own ship. The figure which shows the 2nd image of the predicted avoidance area when another ship is faster than own ship. A diagram showing an image of a predicted avoidance area in a special case where the speed of the other ship and the own ship are the same. A diagram showing an example of the current own ship, destination, and predicted avoidance area. 10 is a diagram expressing the relationship between route point candidates in FIG. 9 using a graph theory tree; FIG. The figure which shows the result of setting the position of other ships 302, 303 at the time when own ship 200 reached the position of point 311-2, and calculating the predicted avoidance area at that time. FIG. 12 is a diagram expressing the relationship between route point candidates in FIG. 11 using a graph theory tree. A diagram showing the time when own ship 200 reaches the position of point 313-2 or the position of point 313-3. 14 is a diagram expressing the relationship between route point candidates in FIG. 13 using a graph theory tree; FIG. The figure which shows the result of setting the position of other ships 302, 303 at the time when own ship 200 reached the position of point 311-4, and calculating the predicted avoidance area at that time. FIG. 16 is a diagram expressing the relationship between route point candidates in FIG. 15 using a graph theory tree. The figure which shows the result of setting the position of other ships 302, 303 at the time when own ship 200 reached the position of point 312-2, and calculating the predicted avoidance area at that time. 18 is a diagram expressing the relationship between route point candidates in FIG. 17 using a graph theory tree; FIG. A diagram showing the time when own ship 200 reaches the position of point 313-2 or the position of point 313-3. FIG. 20 is a diagram expressing the relationship between route point candidates in FIG. 19 using a graph theory tree. A diagram showing the time when own ship 200 reaches the position of point 312-4 via point 311-3. FIG. 22 is a diagram expressing the relationship between route point candidates in FIG. 21 using a graph theory tree. A diagram showing the time when the own ship 200 directly proceeds to point 312-3 and reaches the position of point 312-4. 24 is a diagram expressing the relationship between route point candidates in FIG. 23 using a graph theory tree; FIG. The figure which shows the illustration when a turning angle exceeds a limit angle. A diagram in which the predicted avoidance area has been moved so that the turning angle becomes the limit angle. 27 is a diagram expressing the relationship between route point candidates in FIG. 26 using a graph theory tree; FIG. FIG. 7 is a diagram showing a tree obtained when a recalculation unit 160 is also provided. FIG. 3 is a diagram showing an example in which predicted avoidance areas that are close to each other exist. FIG. 2 is a diagram showing an example of a functional configuration of an avoidance route search support device. FIG. 3 is a diagram showing an example of a processing flow of the avoidance route search support device. FIG. 1 is a diagram showing an example of a functional configuration of a computer.

Embodiments of the present invention will be described in detail below. Note that components having the same functions are given the same numbers and redundant explanations will be omitted.

FIG. 1 shows an example of the functional configuration of an avoidance route search device. FIG. 2 shows an example of the processing flow of the avoidance route search device. The avoidance route search device 100 includes an information collection section 110, a condition setting section 130, a predicted avoidance area calculation section 140, a route search section 150, a repetition control section 180, and a recording section 190. The avoidance route search device 100 may further include an other ship selection section 120, a predicted avoidance area combination section 145, a recalculation section 160, and a route determination section 170.

The information collecting unit 110 collects information on the position and speed of the own ship and other nearby ships (S110). The information collecting unit 110 includes, for example, a position sensor, a speed sensor, an AIS (Automatic Identification System), an ARPA (Automatic Radar Plotting Aid), etc., and receives information from these sensors and devices. All you have to do is integrate the obtained information to obtain information on the position and speed of your own ship and other nearby ships. Note that in this specification, when "speed" is expressed, it means a scalar amount and does not include directional information. When we say "velocity," we mean a vector, which includes both "velocity" and direction, which are scalar quantities. The recording unit 190 records the collected position and speed information of the own ship and other nearby ships.

When the other ship selection section 120 is provided, other ships related to the avoidance route search are selected from among other ships. The timing for selecting other ships may be before or after the processing of the condition setting unit 130, which will be described later. Further, it may be performed both before and after the processing by the condition setting unit 130. Further, when the number of other ships is small, it is not necessary to perform the process of selecting other ships. If carried out before the processing by the condition setting unit 130, the other ship selection unit 120 selects other ships related to the avoidance route search from among the other ships for which information has been collected (S121). Specifically, it is only necessary to select other ships with which the routes may intersect after the current time. When carried out after the processing by the condition setting unit 130, the other ship selection unit 120 selects other ships related to the avoidance route search based on the position and speed conditions of the own ship and other ships set by the condition setting unit 130. Sort (S122). That is, based on the position and speed conditions of the own ship and other ships set by the condition setting unit 130, other ships with which the routes may intersect later may be selected.

The condition setting unit 130 sets conditions for the position and speed of the own ship and other ships (S131). In the first condition setting, the current positions and speeds of the own ship and other ships collected by the information collection unit 110 may be set. Thereafter, the position and speed conditions of the own ship and other ships may be set according to instructions from the repeat control unit 180, which will be described later. Details will be described later.

The predicted avoidance area calculation unit 140 satisfies predetermined avoidance area conditions for each other ship selected by the other ship selection unit 120 based on the positions and speeds of the own ship and other ships set by the condition setting unit 130. A predicted avoidance area is calculated (S141). Figure 3 shows an image of the predicted avoidance area determined using the DCPA circle. As mentioned above, the method of using the DCPA circle has the problem that the predicted avoidance area has too much margin, but even in an area where there are multiple other ships, if the distance between the other ships is large, the DCPA circle is used. Since the route can be searched by using the DCPA circle, the predicted avoidance area calculation unit 140 of the first embodiment may adopt a method using the DCPA circle. The own ship 200 in FIG. 3 is trying to move upward, and the other ship 300 is trying to move leftward. A DCPA circle 210 is drawn around own ship 200. The other ship 300-1 and the DCPA circle 210-1 indicate the timing at which the own ship 200 and the other ship 300 come closest when the own ship 200 passes behind the other ship 300. The other ship 300-2 and the DCPA circle 210-2 indicate the timing at which the own ship 200 and the other ship 300 approach the closest when the own ship 200 passes in front of the other ship 300. The predicted avoidance area 310 has a shape as shown in FIG.

Figure 4 shows the concept of the proposed safety distance. The distance to avoid the other ship 300 in the forward direction is the forward safe distance _LF , the distance to avoid the other ship 300 in the lateral direction is the lateral safe distance _LW , and the distance to avoid the other ship in the rear direction is the rear safe distance _LR . . The forward safety distance L _F , the side safety distance L _W , and the rear safety distance L _R may be determined by a predetermined method depending on the total lengths of the own ship 200 and the other ship 300. For example, when the total length of own ship 200 is L _O and the total length of other ship 300 is L _T , the reference length L is determined as L = (L _O + L _T )/2, and for example,
L _F =12L, L _W =4L, L _R =4L
You can decide as follows. If the settings shown in Figure 4 are used, a safe forward distance is secured when the own ship is located in front of another ship, a lateral safe distance is secured when the own ship is located directly beside the other ship, and a safe distance is secured when the own ship is located directly beside the other ship. A safe rear distance is ensured when a ship is located directly behind another ship, so areas to avoid can be set appropriately.

Figures 5 to 8 show images of predicted avoidance areas. The predicted avoidance area indicates an area through which the own ship 200 cannot pass. Figure 5 shows an image of the predicted avoidance area when the other ship is slower than the own ship and when the speed is the same, and Figure 6 shows the first image of the predicted avoidance area when the other ship is faster than the own ship. Figure 7 shows a second image of the predicted avoidance area when the other ship is faster than the own ship, and Figure 8 shows an image of the predicted avoidance area in a special case where the speed of the other ship and the own ship are the same. ing. Let the speed of own ship 200 be V _O and the speed of other ship 300 be V _T . The four vertices of the predicted avoidance area 310 in FIG. Let the distance be a ₁ and the distance between the line connecting points 310-3 and 310-4 and the other ship 300 be a ₂ . If the angle between the route of the other ship 300 and the direction of the own ship 200 is β, then the distance k between the other ship 300 and the perpendicular line drawn from the own ship 200 to the route of the other ship 300 is dcosβ. Other ship 300-1 indicates the timing when own ship 200 has proceeded to the route of other ship 300 (near the midpoint of points 310-1 and 310-2) via point 310-1. There is. Other ship 300-2 indicates the timing when own ship 200 has proceeded to the route of other ship 300 (near the midpoint between points 310-3 and 310-4). There is. Note that ships cannot make sharp turns, so in the case of Figure 5, when own ship 200 reaches the route of another ship 300 via point 310-1, it actually crosses point 310-1 and point 310-1. It is thought that the signal passes through a position shifted to the right of the midpoint of 310-2, but since the overall error is within the range of error, the shift will be ignored in the calculations below. The distance between the other ship 300-1 and the midpoint between points 310-1 and 310-2 is at least the rear safety distance _LR . The distance between the forward safe distance LF is greater than the forward safety distance L _F , the distance between the other ship 300's route and the line connecting points 310-1 and 310-3 is the side safety distance L _W , and the other ship 300's route and the point 310 The distance between -2 and the line connecting point 310-4 is the lateral safety distance _LW .

When setting the forward safety distance L _F , the side safety distance L _W , and the rear safety distance L _R as described above, the predicted avoidance area calculation unit 140 calculates when the own ship 200 is located in front of the other ship 300 Secure the forward safety distance L _F , secure the lateral safety distance L W when the own ship 200 is located directly beside the other ship 300, and secure the rear safety distance L _W when the own ship 200 is located directly behind the other ship 300. A predicted avoidance area 310 is calculated to ensure L _R (S141). "Calculating the predicted avoidance area 310" means finding the position of the "predicted avoidance area 310." Specifically, the position of the predicted avoidance area 310 may be determined as shown below.

<When passing behind another ship if it is slower than your own ship (see Figure 5)>
The conditions for the own ship 200 to safely pass behind the other ship 300 are as follows.
[1] When the own ship 200 reaches the position of the point 310-1, the other ship 300 is on or passing the midpoint between the points 310-1 and 310-2.
[2] When own ship 200 reaches near the midpoint between points 310-1 and 310-2, other ship 300 is at the position of other ship 300-1.

The distance p ₁ between own ship 200 and point 310-1 is expressed by the following formula.

p ₁ = ((dcosβ-a ₁ ) ² + (dsinβ-L _W ) ² ) ^1/2
The time _S1 until the own ship 200 reaches the point 310-1 is expressed by the following equation.

S ₁ =p ₁ /V _O
=((dcosβ−a ₁ ) ² +(dsinβ−L _W ) ² ) ^1/2 /V _O
At time _S1 , the other ship 300 is moving forward by V _T · _S1 . From condition [1],
a ₁ ≦V _T・S ₁ =V _T・((dcosβ−a ₁ ) ² +(dsinβ−L _W ) ² ) ^1/2 /V _O
holds true. Since a ₁ is positive, by squaring both sides and dividing by (V _T /V _O ) ² , the following equation holds true.

(V _O /V _T ) ²・a ₁ ² ≦(dcosβ−a ₁ ) ² +(dsinβ−L _W ) ²
If we rearrange this formula for a ₁ , we get

（１）

(1)

becomes. Since the other ship 300 is slower than the own ship 200, V _O /V _T becomes larger than 1. Therefore, the quadratic function of a ₁ in equation (1) becomes an upwardly convex quadratic curve. Also, when a ₁ = 0, the left side is positive, so when the equality sign of this equation holds, let the larger solution be a _1max and the smaller solution be a _1min , then a _1max is positive, and a _{1 min} is negative. Since a ₁ is positive as described above, condition [1] is satisfied within the range of 0<a ₁ ≦a _1max .

The time for the own ship 200 to reach near the midpoint between the points 310-1 and 310-2 is S ₁ +L _W /V _O. At this time, the other ship 300 is at the position of the other ship 300-1. Therefore, in order for condition [2] to hold,
V _T・(S ₁ +L _W /V _O )≧a ₁ +L _R
must be met. Therefore,
a ₁ +L _R -L _W・V _T /V _O ≦V _T・S ₁
need to be met. When L _R -L _W・V _T /V _O is negative, a ₁ = a _1max , and when L _R -L _W・V _T /V _O is positive, a ₁ is set to L _R -L _W - It is sufficient to make a smaller than _1max depending on the value of V _T /V _O. Furthermore, since the own ship 200 cannot actually proceed on a straight line connecting points 310-1 and 310-2, _a1 may be adjusted by taking into account the deviation from the straight line.

<When passing in front of another ship when it is slower than your own ship (see Figure 5)>
The conditions for the own ship 200 to safely pass in front of the other ship 300 are as follows.
[3] When the own ship 200 reaches the position of the point 310-4, the other ship 300 is on the midpoint between the points 310-3 and 310-4, or has not yet reached the midpoint.
[4] When own ship 200 reaches near the midpoint between points 310-3 and 310-4, other ship 300 is at the position of other ship 300-2.

The distance _p2 between own ship 200 and point 310-3 is expressed by the following formula.

p ₂ = ((a ₂ −dcosβ) ² +(dsinβ−L _W ) ² ) ^1/2
The time _S2 until the own ship 200 reaches the point 310-3 is expressed by the following equation.

S ₂ =p ₂ /V _O
=((a ₂ −dcosβ) ² +(dsinβ−L _W ) ² ) ^1/2 /V _O
At time _S2 , the other ship 300 is ahead by V _T · _S2 . The time for the own ship 200 to reach near the midpoint between points 310-3 and 310-4 is S ₂ +L _W /V _O. Further, the time for the own ship 200 to reach the point 310-4 is S ₂ +2L _W /V _O.

Since condition [3] holds true,
a ₂ ≧V _T・(S ₂ +2L _W /V _O )
=V _T・(((a ₂ −dcosβ) ² +(dsinβ−L _W ) ² ) ^1/2 +2L _W )/V _O
becomes. Since V _T /V _O is positive, dividing both sides by (V _T /V _O ) and subtracting 2L _w from both sides yields the following equation.

(V _O /V _T )・a ₂ −2L _W ≧((a ₂ −dcosβ) ² +(dsinβ−L _W ) ² ) ^1/2
Since the right side is positive, (V _O /V _T )·a ₂ -2L _W on the left side is also positive. Therefore, by squaring both sides and rearranging for a ₂ , we get

（２）

(2)

becomes. Since the other ship 300 is slower than the own ship 200, the quadratic function of a2 in equation ( ₂ ) becomes an upwardly convex quadratic curve. Also, assuming that d is sufficiently larger than L _W , the left side is positive when a ₂ = 0, so when the equality sign of this equation holds, the larger solution is a _2max and the smaller one is If the solution is a _2min , then a _2max is positive and a _2min is negative. Since a ₂ is positive as described above, condition [3] is satisfied within the range of a _2max ≦a ₂ .

The time for the own ship 200 to reach near the midpoint between points 310-3 and 310-4 is S ₂ +L _W /V _O. At this time, the other ship 300 is at the position of the other ship 300-2. Therefore, in order for condition [4] to hold,
V _T・(S ₂ +L _W /V _O )≦a ₂ -L _F
must be met. Therefore,
a ₂ -L _F +L _W・V _T /V _O ≧V _T・(S ₂ +2L _W /V _O )
need to be met. When L _F −L _W・V _T /V _O is negative, a ₂ = a _2max , and when L _F −L _W・V _T /V _O is positive, a ₂ is set to L _F −L _W - It is sufficient to make a larger than _2max depending on the value of V _T /V _O. Furthermore, in reality, own ship 200 cannot proceed on a straight line connecting points 310-3 and 310-4, so _a2 may be adjusted taking into account the deviation from the straight line.

<When passing behind another ship when it is faster than your own ship (see Figures 6 and 7)>
The conditions are the same as conditions [1] and [2] above. Moreover, the calculations up to equation (1) are the same. Since the other ship 300 is faster than the own ship 200, V _O /V _T becomes smaller than 1. Therefore, the quadratic function of a ₁ in equation (1) becomes a downwardly convex quadratic curve. Further, when a ₁ =0, the left side is positive, and the axis of the quadratic function is positive. Therefore, if there are two solutions for which the equality sign of equation (1) holds, then if the larger solution is a _1max and the smaller solution is a _1min when the equality sign of this equation holds, then Both a _1max and a _1min are positive. Moreover, since a ₁ is positive as described above, condition [1] is satisfied in the range of 0<a ₁ ≦a _1min and a _1max ≦a ₁ . In FIGS. 6 and 7, a _1min is shown as a ₁ and a _1max is shown as a ₄ . In addition, in the case where there is only one solution where the equality sign of equation (1) holds, and when there is no solution, equation ( ₁ ) holds true when a1 is all positive values, so the predicted avoidance area for other ships 300 is Does not exist (there is no need to avoid other ships 300).

The time for the own ship 200 to reach near the midpoint between points 310-a1 and 310-a2 (or near the midpoint between points 310-b3 and 310-b4) is S ₁ +L _W /V _O. At this time, the other ship 300 is at the position of the other ship 300-A1 (or the other ship 300-B2). Therefore, in order for condition [2] to hold,
V _T・(S ₁ +L _W /V _O )≧a ₁ +L _R , V _T・(S ₁ +L _W /V _O )≧a ₄ +L _R
must be met. Therefore,
a ₁ +L _R -L _W・V _T /V _O ≦V _T・S ₁ , a ₄ +L _R −L _W・V _T /V _O ≦V _T・S ₁
need to be met. When L _R -L _W・V _T /V _O is negative, a ₁ = a _1min , a ₄ = a _1max , and when L _R -L _W・V _T /V _O is positive, a ₁ and a ₄ may be made smaller according to the value of L _R -L _W ·V _T /V _O. Also, in reality, the own ship 200 cannot proceed on a straight line connecting points 310-a1 and 310-a2 (or points 310-b3 and 310-b4), so taking into account the deviation from the straight line, a ₁ (or a ₄ ) may be adjusted.

<When passing in front of another ship when it is faster than your own ship (see Figure 6)>
The conditions are the same as conditions [3] and [4] above. Moreover, the calculations up to equation (2) are the same. Since the other ship 300 is faster than the own ship 200, V _O /V _T becomes smaller than 1. Therefore, the quadratic function of a2 in equation ( ₂ ) becomes a downwardly convex quadratic curve. Further, assuming that d is sufficiently larger than L _W , the left side is positive when a ₂ =0, and the axis of the quadratic function is positive. Therefore, if there is a solution for which the equality sign of equation (2) holds, then if the larger solution is a _2max and the smaller solution is a _2min when the equality sign of this equation holds, then a _2max and _a2min are also positive. Therefore, condition [3] is satisfied within the range of a _2min ≦a ₂ ≦a _2max . In FIG. 6, a _2min is shown as a ₂ and a _2max is shown as a ₃ . Note that if there is no solution for which the equality sign of Equation (2) holds, Equation (2) does not hold when a ₁ is all positive values. This means that the ship cannot safely pass in front of the other ship 300.

The time for the own ship 200 to reach near the midpoint between points 310-a3 and 310-a4 (or near the midpoint between points 310-b1 and 310-b2) is S ₂ +L _W /V _O. At this time, the other ship 300 is at the position of the other ship 300-A2 (or the other ship 300-B1). Therefore, in order for condition [4] to hold,
V _T・(S ₂ +L _W /V _O )≦a ₂ −L _F , V _T・(S ₂ +L _W /V _O )≦a ₃ −L _F
must be met. Therefore,
a ₂ −L _F +L _W・V _T /V _O ≧V _T・(S ₂ +2L _W /V _O ),
a ₃ -L _F +L _W・V _T /V _O ≧V _T・(S ₂ +2L _W /V _O )
need to be met. When L _F −L _W・V _T /V _O is negative, a ₂ = a _2min , a ₃ = a _2max , and when L _F −L _W・V _T /V _O is positive, a ₂ and a ₃ may be increased according to the value of L _F −L _W ·V _T /V _O. Also, in reality, the own ship 200 cannot proceed on a straight line connecting points 310-a3 and 310-a4 (or points 310-b1 and 310-b2), so taking into account the deviation from the straight line, a ₂ (or a ₃ ) may be adjusted.

Note that the example in FIG. 6 shows a case where there are two solutions in which the equality sign holds for both equation (1) and equation (2). Further, the example in FIG. 7 shows a case where there are two solutions in which the equality sign holds true for equation (1), but there is no solution in which the equality sign holds in equation (2).

<When passing behind another ship when the speed of the other ship and own ship are almost the same (see Figures 5 and 8)>
The conditions are the same as conditions [1] and [2]. Moreover, the calculations up to equation (1) are the same. Since the speeds of the other ship 300 and the own ship 200 are almost the same, V _O /V _T ≈1, which is a linear function. When the solution of this linear function is a _1equ , since a _1equ is a positive value, there always exists a1 that satisfies equation (1), and satisfies condition [1] in the range of 0<a ₁ ≦a _1equ .

The time for the own ship 200 to reach near the midpoint between the points 310-1 and 310-2 is S ₁ +L _W /V _O. At this time, the other ship 300 is at the position of the other ship 300-1. Therefore, in order for condition [2] to hold,
V _T・(S ₁ +L _W /V _O )≧a ₁ +L _R
must be met. Therefore,
a ₁ +L _R -L _W・V _T /V _O ≦V _T・S ₁
need to be met. When L _R -L _W・V _T /V _O is negative, a ₁ = a _1equ , and when L _R -L _W・V _T /V _O is positive, a ₁ is set to L _R -L _W - It may be made smaller than a _1equ depending on the value of V _T /V _O. Furthermore, since the own ship 200 cannot actually proceed on a straight line connecting points 310-1 and 310-2, _a1 may be adjusted by taking into account the deviation from the straight line.

<When passing in front of another ship when the speed of the other ship and own ship are almost the same (see Figures 5 and 8)>
The conditions are the same as conditions [3] and [4] above. Moreover, the calculations up to equation (2) are the same. Since the speeds of the other ship 300 and the own ship 200 are almost the same, V _O /V _T ≈1, which is a linear function. If the solution of this linear function is a _1equ , then condition [3] is satisfied within the range of a _1equ ≦a ₁ .

The time for the own ship 200 to reach near the midpoint between points 310-3 and 310-4 is S ₂ +L _W /V _O. At this time, the other ship 300 is at the position of the other ship 300-2. Therefore, in order for condition [4] to hold,
V _T・(S ₂ +L _W /V _O )≦a ₂ -L _F
must be met. Therefore,
a ₂ -L _F +L _W・V _T /V _O ≧V _T・(S ₂ +2L _W /V _O )
need to be met. When L _F −L _W・V _T /V _O is negative, a ₂ = a _2max , and when L _F −L _W・V _T /V _O is positive, a ₂ is set to L _F −L _W - It is sufficient to make a larger than _2max depending on the value of V _T /V _O.

Furthermore, if L _w is sufficiently small compared to d, then
a _1equ ≒d/2cosβ
becomes. When the angle β is 60 degrees, a _1equ ≈d, and as the angle β increases, a _1equ also increases. In other words, if the speed of your own ship and the other ship are almost the same, and you proceed in the same direction, you will need a very long distance to cross while maintaining a safe distance. Therefore, if the speeds of the other ship 300 and the own ship 200 are about the same and the angle β is larger than a predetermined angle, it is impossible to select a route that passes in front of the other ship 300. The predicted avoidance area 310 may be set as shown in FIG.

After calculating the predicted avoidance area 310, the route search unit 150 determines whether there is any predicted avoidance area on a straight line connecting the predetermined destination and the own ship 200 set by the condition setting unit 130. Route point candidates are searched from points on the boundary line of the predicted avoidance area that satisfy predetermined route search conditions (S142, S151). In other words, the avoidance route search device 100 checks whether there is any predicted avoidance area on the straight line connecting the predetermined destination and the own ship 200 set by the condition setting unit 130 (S142). If step S142 is NO, the avoidance route search device 100 checks whether the condition setting unit 130 has set all the conditions to be set (S132).

If step S132 is YES, if the route determining unit 170 is provided, the route determining unit 170 selects a route from the current position of the ship to the destination as route point candidates according to predetermined priority conditions. (S170). For example, if there is no predicted avoidance area that blocks the straight line connecting the current own ship 200 and the destination, there are no route point candidates and a straight route to the destination is determined. If there are route point candidates, a route may be determined according to predetermined priority conditions. For example, the priority condition may be that the distance is short, the priority condition may be that the arrival time is short, or the priority condition may be that the total number of predicted avoidance areas that must be avoided is small. If the route determination unit 170 is not provided, a person may determine the route based on the current position of the ship, the destination, and route point candidates. Further, even when the route determination unit 170 is provided, a plurality of priority conditions may be set, the avoidance route search device 100 may indicate a desirable route for each priority condition, and a person may select a route from among them. .

If step S132 is NO, the condition setting unit 130 sets the next condition (S131). If step S142 is YES, the route search unit 150 searches for route point candidates from points on the boundary line of the predicted avoidance area that satisfy predetermined route search conditions (S151). Next, the search for route point candidates and route determination will be described in detail with reference to FIGS. 9 to 29. FIG. 9 is a diagram showing an example of the current own ship, destination, and predicted avoidance area. Own ship 200 is heading for destination 290. Other ships 301, 302, and 303 are navigating ahead of own ship 200, and predicted avoidance areas 311, 312, and 313 exist. At the four corner points of the predicted avoidance areas 311, 312, and 313, "-1", "-2", "-3", and "-4" are attached to the respective predicted avoidance area codes. For example, the route search unit 150 determines, among the points on the boundary line of the predicted avoidance area on the straight line connecting the destination 290 and own ship 200, the point where the turning angle to the right is the largest and the point where the turning angle to the left is the largest. The points where the turning angle is the largest are taken as both end points, and when there is no other predicted avoidance area on the straight line connecting both end points and own ship 200, the end points are taken as route point candidates. The “course angle” indicates a difference in direction with respect to a straight line connecting own ship 200 and destination 290. In the case of FIG. 9, the end points are points 311-1, 312-1, 311-3, and 312-2. However, since the predicted avoidance area 311 is on the straight line connecting the point 312-1 and the own ship 200, there are three route point candidates: points 311-1, 311-3, and 312-2. FIG. 10 is a diagram expressing the relationship between route point candidates in FIG. 9 using a graph theory tree. When own ship 200 passes point 311-1, it will proceed in the direction of destination 290 while avoiding entering the predicted avoidance area 311 to which point 311-1 belongs, so if it tries to choose the shortest possible route. It also passes through point 311-2. Therefore, in the tree of FIG. 10, points 311-1 and 311-2 are connected. Similarly, points 311-3 and 311-4 and points 312-3 and 312-4 are connected. Although FIG. 9 shows an example in which the other ships 301, 302, and 303 all proceed from the right direction to the left direction of their own ship, they may also include ships proceeding from the left direction to the right direction, or they may proceed diagonally from the left direction to the right direction. may include ships proceeding to

In addition, when there is a predicted avoidance area on a straight line connecting both end points and own ship 200, the route search unit 150 determines whether to change course to the right among points on the boundary line of the predicted avoidance area on the straight line. The point where the angle is the largest and the point where the turning angle to the left is the largest are taken as both end points, and for each end point, if there is no other predicted avoidance area on the straight line connecting both end points and own ship 200, Both end points are designated as route point candidates. In the case of the example in FIG. 9, the points 312-1 are both end points, and the predicted avoidance area 311 is on the straight line connecting with the own ship 200. In this case, points 311-1 and 311-3, which are both end points of the predicted avoidance area 311, are set as route point candidates. However, since it has already been selected as a route point candidate in the previous process, it is not added to FIG. 10 here.

For each route point candidate, the repeat control unit 180 sets one of the points on the boundary line of the predicted avoidance area to which the route point candidate belongs to the position of the own ship 200 proceeding in the direction of the destination 290, and sets the own ship 200 to the position. Instructs the condition setting unit 130 to set the positions of other ships 301, 302, and 303 from the time when the ship 200 arrives, and repeats the processing of the condition setting unit 130, predicted avoidance area calculation unit 140, and route search unit 250. (S152). "The position of the own ship 200 proceeding in the direction of the destination 290 at one of the points on the boundary line of the predicted avoidance area to which the route point candidate belongs" means the point 311-2 in the case of the route point candidate 311-1; The point candidate 311-3 is the point 311-4, and the route point candidate 312-3 is the point 312-4. In addition, when the other ship sorting part 120 performs step S122, step S122 is also included in the repeated process.

FIG. 11 shows the results of setting the positions of other ships 302 and 303 at the time when own ship 200 reaches the position of point 311-2, and calculating the predicted avoidance area at that time. The route search unit 150 determines the point where the turning angle to the right is the largest and the turning angle to the left among the points on the boundary line of the predicted avoidance area on the straight line connecting the destination 290 and the own ship 200. The points where is the largest are taken as both end points, and if there is no other predicted avoidance area on the straight line connecting both end points and own ship 200, the end points are taken as route point candidates. In the case of FIG. 11, both end points are points 313-2 and 313-3. Since there is no predicted avoidance area on the straight line connecting both end points and own ship 200, there are two route point candidates, points 313-2 and 313-3. FIG. 12 is a diagram expressing the relationship between route point candidates in FIG. 11 using a graph theory tree. When the own ship 200 passes through the point 313-2, it proceeds directly toward the destination after passing through the point 313-2, so it does not pass through other points in the predicted avoidance area 313 to which the point 313-2 belongs. Even when passing point 313-3, the vehicle proceeds to the destination without passing through the point on the boundary line of predicted avoidance area 313 again after passing point 313-3. Therefore, in the tree of FIG. 12, points 313-2 and 313-3 are added.

FIG. 13 shows the state at the time when the own ship 200 reaches the position of point 313-2 or the position of point 313-3. FIG. 14 is a diagram expressing the relationship between route point candidates in FIG. 13 using a graph theory tree. Since there is no predicted avoidance area that blocks the straight line connecting destination 290 and own ship 200, destination 290 is connected to points 313-2 and 313-3, respectively, in the tree of FIG. In the case of FIG. 13, the result in step S142 is NO, and the result in step S132 is also NO, so the process returns to the condition setting step S131.

In condition setting step S131, the positions of other ships 302 and 303 at the time when own ship 200 reaches the position of point 311-4 are set. FIG. 15 shows the results of calculating the predicted avoidance area at that time. Since the predicted avoidance area 312 blocks the straight line connecting the destination 290 and own ship 200, among the points on the boundary line of the predicted avoidance area 312, the points 312-1 and 312-1 where the turning angle to the right is the largest and the leftward direction. The point 312-3 where the turning angle is the largest is defined as both end points. Since there is no other predicted avoidance area on the straight line connecting both end points and own ship 200, the respective end points 312-1 and 312-3 are selected as route point candidates. FIG. 16 is a diagram expressing the relationship between route point candidates in FIG. 15 using a graph theory tree. When the ship 200 passes the point 312-1, it moves toward the destination 290 while avoiding entering the predicted avoidance area 312 to which the point 312-1 belongs, so if it tries to choose the shortest route possible, the point 312-2 also passes. Therefore, in the tree of FIG. 16, points 312-1 and 312-2 are connected. Similarly, points 312-3 and 312-4 are connected.

FIG. 17 shows the results of setting the positions of other ships 302 and 303 at the time when own ship 200 reaches the position of point 312-2, and calculating the predicted avoidance area at that time. In the case of FIG. 17, both end points are points 313-1 and 313-3. Since there is no predicted avoidance area on the straight line connecting both end points and own ship 200, there are two route point candidates, points 313-1 and 313-3. FIG. 18 is a diagram expressing the relationship between route point candidates in FIG. 17 using a graph theory tree. When the ship 200 passes the point 313-1, it will proceed in the direction of the destination 290 while avoiding entering the predicted avoidance area 313 to which the point 313-1 belongs, so if it tries to choose the shortest route possible, the point 313-2 will also pass. When the own ship 200 passes the point 313-3, it proceeds directly toward the destination after passing the point 313-3, so it does not pass any other points in the predicted avoidance area 313 to which the point 313-3 belongs. Therefore, in the tree in FIG. 18, point 313-2 is connected to point 313-1, and nothing is connected to point 313-3.

FIG. 19 shows the state of the time when the own ship 200 reaches the position of point 313-2 or the position of point 313-3. FIG. 20 is a diagram expressing the relationship between route point candidates in FIG. 19 using a graph theory tree. Since there is no predicted avoidance area that blocks the straight line connecting destination 290 and own ship 200, destination 290 is connected to points 313-2 and 313-3, respectively, in the tree of FIG. In the case of FIG. 19, step S142 is NO, and step S132 is also NO, so the process returns to condition setting step S131.

In the condition setting step S131, the positions of the other ships 302 and 303 are set at the time when the own ship 200 reaches the position of the point 312-4 via the point 311-3. FIG. 21 shows the state at the time when the own ship 200 reaches the position of point 312-4 via point 311-3. FIG. 22 is a diagram expressing the relationship between route point candidates in FIG. 21 using a graph theory tree. Since there is no predicted avoidance area that blocks the straight line connecting destination 290 and own ship 200, destination 290 is connected to point 312-4 in the tree of FIG. 22. In the case of FIG. 21, the result in step S142 is NO, and the result in step S132 is also NO, so the process returns to the condition setting step S131.

In the condition setting step S131, the positions of other ships 302 and 303 are set at the time when the own ship 200 directly advances from the current position to the point 312-3 and reaches the position of the point 312-4. FIG. 23 shows the situation at the time when the own ship 200 directly proceeds to the point 312-3 and reaches the position of the point 312-4. FIG. 24 is a diagram expressing the relationship between route point candidates in FIG. 23 using a graph theory tree. Since there is no predicted avoidance area that blocks the straight line connecting destination 290 and own ship 200, destination 290 is connected to point 312-4 in the tree of FIG. At the time of FIG. 23, all the conditions have been set, so the answer to step S142 is NO, and the answer to step S132 is YES, so if the route determining section 170 is provided, the process advances to route determining step S170. If the route determination unit 170 is not provided, route candidates according to the tree shown in FIG. 24 are output and the process is terminated.

The route determining unit 170 determines a route from the current position of the ship to the destination based on route point candidates according to predetermined priority conditions (S170). As described above, the predetermined priority conditions include short distance, short arrival time, and small total predicted avoidance area that must be avoided, but are not limited to these. The route determining unit 170 may use the tree shown in FIG. 24 to determine the route according to the priority conditions.

As described above, the route search unit 150 satisfies the predetermined route search conditions when any predicted avoidance area is on the straight line connecting the predetermined destination and the own ship set by the condition setting unit. Route point candidates are searched from points on the boundary line of the predicted avoidance area. This means that the route search unit 150 obtains route point candidates at least when there is a predicted avoidance area that blocks the route. The route search unit 150 may also find route point candidates when there is no blocking predicted avoidance area or on the boundary line of the predicted avoidance area that is not blocking the predicted avoidance area. For example, the route search unit 150 may create a graph theory tree by listing possible route point candidates from all combinations of predicted avoidance areas. Although calculations will be made for routes that should not actually be selected, the process of ``Is there a predicted avoidance area that will block the route?'' (S142) can be omitted. Furthermore, existing search techniques may be used as appropriate. In other words, the "predetermined route search conditions" for searching route point candidates from points on the boundary line of the predicted avoidance area may be other than the method described using FIGS. 9 to 24.

In the explanation up to this point, the range of course angles has not been considered. For example, when the route search unit 150 searches for route point candidates from points on the boundary line of the predicted avoidance area, it sets the maximum angle of the turning angle during the search, and searches for route point candidates within the range where the turning angle < the maximum angle. You can explore. Further, a range of desirable course angles may be determined. For example, it is easy to change the speed of a small boat. When passing behind another ship, you can reduce the turning angle by slowing down the speed. Also, when passing in front of another ship, increasing the speed can reduce the turning angle. Therefore, if the turning angle exceeds a predetermined "limit angle", it may be possible to select a route by changing the speed. Although it is considered that the limiting angle may be appropriately set, for example, from 10 degrees to 15 degrees, it is not limited to this range.

In that case, the avoidance route search device 100 may also include a recalculation unit 160. On the premise that the speed of the own ship can be changed, the recalculation unit 160 calculates the speed of the own ship when the turning angle becomes larger than the limit angle, which is a predetermined angle, in order to proceed to the route point candidate. The speed of the own ship and the position of the route point candidate are determined so that the turning angle for proceeding to the route point candidate, which is to be moved by changing the speed, becomes the limit angle (S161, S162). In this case, the repeating process also includes the processing of the recalculation unit (S161, S162), and when the recalculation unit 160 has determined the speed of the own ship and the route point candidate, the iterative control unit 180 will The predicted avoidance area to which the point candidate belongs is moved according to the route point candidate, and the above-mentioned repeating process is performed.

Steps S161 and S162 will be explained using FIGS. 25 to 28. FIG. 25 shows an example where the turning angle exceeds the limit angle. FIG. 25 shows the same state as FIG. 17, and shows that the turning angle for the own ship 200 to proceed to point 313-1 is larger than the limit angle θ _L. In this case, by slowing down the speed of own ship 200, point 313-1, which is a route point candidate, can be moved to the left. FIG. 26 shows a diagram in which the predicted avoidance area has been moved so that the turning angle becomes the limit angle. The predicted avoidance area 313' is the predicted avoidance area to which the vehicle has moved. Point 313'-1 is a route point candidate when the speed is slowed down. FIG. 27 corresponds to FIG. 18 and is a diagram expressing the relationship between route point candidates in FIG. 26 using a graph theory tree. Points 313-1 and 313-3 obtained in FIGS. 17 and 18 are left on the tree, and point 313'-1 is also added. FIG. 28 is a tree corresponding to FIG. 24, and shows a tree obtained when the recalculation unit 160 is also included. If the recalculation unit 160 is also provided, the turning angle can be reduced, so that the vessel can efficiently navigate to the destination.

Next, a case where the predicted avoidance area coupling section 145 is provided will be described. The process of the predicted avoidance area combination unit 145 is performed after the process of the predicted avoidance area calculation unit 140 (S141). When the predicted avoidance areas calculated by the predicted avoidance area calculation unit 140 satisfy a predetermined condition indicating that they are close to each other, the predicted avoidance area combination unit 145 combines the plurality of predicted avoidance areas that satisfy the condition into one prediction. It is set as an avoidance area (S145). In this case, the iterative process also includes the process of the predicted avoidance area combination unit 145. This will be explained using FIG. 29. FIG. 29 is a diagram illustrating an example in which predicted avoidance areas that are close to each other exist. It is assumed that predicted avoidance areas 311, 312, and 313 are calculated by the process of the predicted avoidance area calculation unit 140. Here, the above-mentioned "predetermined condition indicating that they are close to each other" means that the combination judgment lines 321, 322, and 323 set around the predicted avoidance area overlap. The connection determination line may be set to be a predetermined distance away from the predicted avoidance area. As shown in FIG. 29, when the predicted avoidance areas 311, 312, and 313 satisfy the condition that they are close to each other, the outer circumferences of the predicted avoidance areas 311, 312, and 313 are connected to form one predicted avoidance area. The area 330 may be used. Note that the two end points of the predicted avoidance area 330 in this case are the point 311-1 and the point 312-3, and these points become route point candidates. When predicted avoidance areas are densely packed, it is difficult to navigate while passing between the predicted avoidance areas. By selecting route point candidates so as not to perform the process of searching for a route that would pass through, the processing load can be reduced.

According to the avoidance route search device 100, the processes of the condition setting section 130, the predicted avoidance area calculation section 140, and the route search section 150 are repeatedly performed, so that a route can be searched even in a sea area where a plurality of other ships exist.

FIG. 30 shows an example of the functional configuration of the avoidance route search support device, and FIG. 31 shows an example of the processing flow of the avoidance route search support device. The avoidance route search support device 101 includes at least an information collection section 110 and a predicted avoidance area calculation section 140. Let the distance to avoid in the forward direction of the ship 300 be a forward safe distance _LF , the distance to avoid in the side direction of the other ship 300 as a lateral safe distance _LW , and the distance to avoid in the rear direction of the other ship as a rear safe distance _LR .

The information collecting unit 110 collects information on the position and speed of the own ship and other nearby ships (S110). The information collecting unit 110 includes, for example, a position sensor, a speed sensor, an AIS (Automatic Identification System), an ARPA (Automatic Radar Plotting Aid), etc., and receives information from these sensors and devices. All you have to do is integrate the obtained information to obtain information on the position and speed of your own ship and other nearby ships. The recording unit 190 records the collected position and speed information of the own ship and other nearby ships.

The predicted avoidance area calculation unit 140 secures a forward safe distance when the own ship is located in front of another ship, secures a lateral safe distance when the own ship is located directly beside the other ship, and A predicted avoidance area is calculated to ensure a safe distance to the rear when the ship is located directly behind another ship (S141). The specific calculation method performed by the predicted avoidance area calculation unit 140 is the same as in the first embodiment.

According to the avoidance route search support device 101, when the own ship is located in front of another ship, the forward safe distance L _F is secured, and when the own ship is located right next to the other ship, the lateral safe distance L _W is secured. When your own ship is located directly behind another ship, a safe rear distance _LR is secured, so you can appropriately set the area to avoid.

[Program, recording medium]
The various processes described above are performed by causing the recording unit 2020 of the computer 2000 shown in FIG. This can be done by letting

A program describing the contents of this process can be recorded on a computer-readable recording medium. The computer-readable recording medium may be of any type, such as a magnetic recording device, an optical disk, a magneto-optical recording medium, or a semiconductor memory.

Further, this program is distributed by, for example, selling, transferring, lending, etc. a portable recording medium such as a DVD or CD-ROM on which the program is recorded. Furthermore, this program may be distributed by storing the program in the storage device of the server computer and transferring the program from the server computer to another computer via a network.

A computer that executes such a program, for example, first stores a program recorded on a portable recording medium or a program transferred from a server computer in its own storage device. When executing a process, this computer reads a program stored in its own recording medium and executes a process according to the read program. In addition, as another form of execution of this program, the computer may directly read the program from a portable recording medium and execute processing according to the program, and furthermore, the program may be transferred to this computer from the server computer. The process may be executed in accordance with the received program each time. In addition, the above-mentioned processing is executed by a so-called ASP (Application Service Provider) type service, which does not transfer programs from the server computer to this computer, but only realizes processing functions by issuing execution instructions and obtaining results. You can also use it as Note that the program in this embodiment includes information that is used for processing by an electronic computer and that is similar to a program (data that is not a direct command to the computer but has a property that defines the processing of the computer, etc.).

Further, in this embodiment, the present apparatus is configured by executing a predetermined program on a computer, but at least a part of these processing contents may be realized by hardware.

100 Avoidance route search device 101 Avoidance route search support device 110 Information collection unit 120 Other ship selection unit 130 Condition setting unit 140 Predicted avoidance area calculation unit 145 Predicted avoidance area combination unit 150 Route search unit 160 Recalculation unit 170 Route determination unit 180 Repetition Control unit 190 Recording unit

Claims (15)

an information collection unit that collects information on the position and speed of the own ship and other ships in the vicinity;
a condition setting section that sets conditions for the position and speed of own ship and other ships;
a predicted avoidance area calculation unit that calculates a predicted avoidance area that is an area that satisfies predetermined avoidance area conditions for each other ship based on the positions and speeds of the own ship and other ships set by the condition setting unit;
If any of the predicted avoidance areas is on a straight line connecting the predetermined destination and the own ship set by the condition setting section, the area on the boundary line of the predicted avoidance area that satisfies the predetermined route search conditions. a route search unit that searches for route point candidates from points;
For each route point candidate, one of the points on the boundary line of the predicted avoidance area to which the route point candidate belongs is set as the position of the own ship proceeding in the direction of the destination, and from the time when the own ship reaches the position. a repetition control unit that instructs the condition setting unit to set the position of another ship, and causes the condition setting unit, the predicted avoidance area calculation unit, and the route search unit to repeat processing;
An avoidance route search device comprising: The avoidance route search device according to claim 1,
It is possible to change the speed of own ship,
If the turning angle in order to proceed to the route point candidate is larger than the limit angle, which is a predetermined angle, the turning angle in order to proceed to the route point candidate, which is a predetermined angle, is determined by changing the own ship's speed. a recalculation unit that calculates the speed of own ship and the position of the route point candidate so that
Also equipped,
The iterative processing also includes the processing of the recalculation unit, and when the recalculation unit calculates the own ship's speed and the route point candidate, the iterative control unit calculates the predicted avoidance area to which the route point candidate belongs. An avoidance route search device that moves according to route point candidates and performs the above-mentioned repetitive processing. The avoidance route search device according to claim 1 or 2,
The avoidance route search device also includes an other ship selection unit that selects other ships related to the avoidance route search from among the other ships for which the information has been collected. The avoidance route search device according to claim 1 or 2,
It also includes an other ship selection unit that selects other ships related to the avoidance route search based on the position and speed conditions of the own ship and other ships set by the condition setting unit,
The avoidance route search device, wherein the repetitive processing also includes processing of the other ship selection section. The avoidance route search device according to any one of claims 1 to 4,
An avoidance route search device further comprising: a route determination unit that determines a route from the current position of the ship to the destination based on the route point candidates according to predetermined priority conditions. The avoidance route search device according to any one of claims 1 to 5,
When the predicted avoidance areas calculated by the predicted avoidance area calculation unit satisfy a predetermined condition indicating that they are close to each other, the predicted avoidance areas are combined into one predicted avoidance area, which combines the plurality of predicted avoidance areas that satisfy the condition. We also have a department.
The avoidance route search device is characterized in that the iterative processing also includes processing of the predicted avoidance area combination unit. The avoidance route search device according to any one of claims 1 to 6,
The distance to avoid in the forward direction of the other ship is the forward safety distance, the distance to avoid in the side direction of the other ship is the lateral safety distance, and the distance to avoid in the rear direction of the other ship is the rear safety distance,
The predicted avoidance area calculation unit includes:
The forward safety distance is secured when the own ship is located in front of the other ship, the lateral safety distance is secured when the own ship is located directly beside the other ship, and the own ship is located in front of the other ship. An avoidance route search device that calculates a predicted avoidance area so as to secure the safe rear distance when the vehicle is positioned directly behind the vehicle. The avoidance route search device according to claim 7,
The route search unit includes:
Among the points on the boundary line of the predicted give-way area on the straight line connecting the destination and own ship, the point where the turning angle to the right is the largest and the point where the turning angle to the left is the largest are both ends. A dodging route searching device characterized in that, for each end point, when there is no other predicted avoidance area on a straight line connecting both end points and the own ship, the both end points are set as the route point candidates. The avoidance route search device according to claim 8,
The route search unit includes:
If there is a predicted avoidance area on a straight line connecting both end points and own ship, among the points on the boundary line of the predicted avoidance area on the straight line, the point where the turning angle to starboard is the largest and the left The points where the turning angle in the direction is the largest are taken as both end points, and for each end point, if there is no other predicted avoidance area on the straight line connecting both end points and the own ship, the said end points are considered as the route point candidates. An avoidance route search device characterized by: an information gathering step of collecting information on the position and speed of the own ship and other nearby ships;
a condition setting step for setting position and speed conditions of own ship and other ships;
a predicted avoidance area calculation step of calculating a predicted avoidance area that is an area that satisfies predetermined avoidance area conditions for each other ship based on the positions and speeds of the own ship and other ships set in the condition setting step;
If any of the predicted avoidance areas is on a straight line connecting the predetermined destination and the own ship set in the condition setting step, the area on the boundary line of the predicted avoidance area that satisfies the predetermined route search conditions. a route searching step of searching for route point candidates from the points;
For each route point candidate, one of the points on the boundary line of the predicted avoidance area to which the route point candidate belongs is set as the position of the own ship proceeding in the direction of the destination, and from the time when the own ship reaches the position. an iterative control step instructing the condition setting step to set the position of another ship, and repeating the processing of the condition setting step, the predicted avoidance area calculation step, and the route search step;
A method of searching for an avoidance route. The avoidance route search method according to claim 10 ,
It is possible to change the speed of own ship,
If the turning angle in order to proceed to the route point candidate is larger than the limit angle, which is a predetermined angle, the turning angle in order to proceed to the route point candidate, which is a predetermined angle, is determined by changing the own ship's speed. a recalculation step of determining the speed of own ship and the position of the route point candidate so that
also has
The iterative process also includes the process of the recalculation step, and when the recalculation step calculates the own ship's speed and the route point candidate, the iterative control step calculates the predicted avoidance area to which the route point candidate belongs. A method for searching for an avoidance route, comprising moving according to a route point candidate and repeating the process. The avoidance route searching method according to claim 10 or 11 ,
The distance to avoid in the forward direction of the other ship is the forward safety distance, the distance to avoid in the side direction of the other ship is the lateral safety distance, and the distance to avoid in the rear direction of the other ship is the rear safety distance,
The predicted avoidance area calculation step includes:
The forward safety distance is secured when the own ship is located in front of the other ship, the lateral safety distance is secured when the own ship is located directly beside the other ship, and the own ship is located in front of the other ship. A method for searching for an avoidance route, comprising calculating a predicted avoidance area so as to secure the safe rear distance when the vehicle is located directly behind the vehicle. The avoidance route search method according to claim 1 or 2 ,
The route searching step includes:
Among the points on the boundary line of the predicted give-way area on the straight line connecting the destination and own ship, the point where the turning angle to the right is the largest and the point where the turning angle to the left is the largest are both ends. A method for searching for an avoidance route, characterized in that for each endpoint, if there is no other predicted avoidance area on a straight line connecting both endpoints and the own ship, the two endpoints are selected as the route point candidates. The avoidance route search method according to claim 13,
The route searching step includes:
If there is a predicted avoidance area on a straight line connecting both end points and own ship, among the points on the boundary line of the predicted avoidance area on the straight line, the point where the turning angle to starboard is the largest and the left The points where the turning angle in the direction is the largest are taken as both end points, and for each end point, if there is no other predicted avoidance area on the straight line connecting both end points and the own ship, the said end points are considered as the route point candidates. An avoidance route search method characterized by: A program for causing a computer to function as the avoidance route search device according to any one of claims 1 to 9.

Images