A method for calculating the non-safe range of a ship's route

Abstract

The present invention belongs to the technical field of ship navigation safety, and particularly relates to a method for calculating the non-safe range of a ship's route. The steps of the method are as follows: First, establish the coordinate system of the model; Second, determine the safety situation of the voyage section; Third, calculate the non-safe range of the route. The calculation model proposed by the present invention can conveniently and quickly calculate the non-safe range on the route, and can be used as an auxiliary calculation tool for relevant systems of ship navigation operations, so as to better assist navigators in carrying out work such as local modification or re-planning of the route.

Description

Technical Field

[0001] The present invention belongs to the technical field of ship navigation safety, and particularly relates to a method for calculating the non-safe range of a ship's route. Background Art

[0002] To enhance navigation safety and economy, a ship should formulate a route before departure. Among them, waters such as restricted waters, fishing nets, and navigation-obstructing objects belong to non-safe navigation areas and should be avoided as much as possible. Therefore, after formulating a route, it is necessary to conveniently and quickly determine whether the route enters a non-safe area, and on this basis, calculate the non-safe range of the route to assist navigators in local modification or re-formulation of the route and other work.

[0003] At present, the non-safe range of the route mainly depends on manual visual identification on the nautical chart to distinguish which parts of the route enter the non-safe area. This method has poor accuracy and low efficiency. When there are many non-safe areas or the route is complex, it is simply impossible to conveniently and quickly determine the non-safe range of the route. Therefore, there is an urgent need for a method for calculating the non-safe range of a ship's route. Summary of the Invention

[0004] The present invention provides a method for calculating the non-safe range of a ship's route. For the calculation problem of the non-safe range of a ship's route, problem and requirement analysis and determination of the route safety situation are carried out, and on this basis, a calculation model for the non-safe range of the route is proposed.

[0005] The technical solution of the present invention:

[0006] A method for calculating the non-safe range of a ship's route includes the following steps:

[0007] The first step is to establish the coordinate system of the model

[0008] As Figure 1 , establish a plane rectangular coordinate system xOy; assume that the non-safe area is approximately a rectangular area, denoted as rectangle ABCD, with its center point O, length a, and width b; take point O as the origin of the coordinate system, the true north direction as the positive direction of the y-axis, and rotate 90° clockwise as the positive direction of the x-axis.

[0009] Assume that the ship's route is l H , the positions of the two endpoints and each turning point of the route are respectively denoted as {H 1 , H 2 , …, H n}, each turning point divides the route into n - 1 segments, denoted as {S 1 , S 2 , …, S n-1}, for the segment S i , its two endpoints are H i and H i+1, i = 1, 2, …, n - 1.

[0010] Step 2: Determine flight segment S i Safety situation

[0011] Flight segment S i has two endpoints H i and H i+1 . According to the positional relationship between points H i and H i+1 and the non - safe area rectangle ABCD, the flight segment S i can be determined as safe or not according to the following 13 cases.

[0012] 2.1 Case 1: Points H i and H i+1 are both outside the rectangle ABCD, and l S (the straight line where the flight segment S i is located) does not intersect with the rectangle

[0013] 1. Method for judging whether points H i and H i+1 are outside the rectangle ABCD

[0014]

[0015] 2. Method for judging that l S does not intersect with the rectangle ABCD

[0016] The equation of the straight line l S is:

[0017] When x i ≠ x i+1 , y i ≠ y i+1 :

[0018]

[0019] When x i = x i+1 :

[0020] x = x i

[0021] When y i = y i+1 :

[0022] y = y i

[0023] The equation of the straight line l AD where the long side AD of the rectangle is located is y = b / 2, and the equation of the straight line l BC where the long side BC is located is y = -b / 2; the equation of the straight line l ABThe equation is x = -a / 2, and the straight line l where the short side DC is located DC The equation is x = a / 2.

[0024] Let l S The intersection point with the straight line where the long side of the rectangle is located is J a , where the intersection point with AD is J a1 and the intersection point with BC is J a2 ; the intersection point with the straight line where the short side of the rectangle is located is J b , where the intersection point with AB is J b1 and the intersection point with DC is J b2 .

[0025] The judgment method is:

[0026] Therefore, in Case 1, the flight segment S i has no intersection with the rectangle and does not enter the non-safe area, that is, it is safe.

[0027] 2.2 Case 2: Points H i , H i+1 are both outside the rectangle ABCD, and I S intersects with the rectangle, and the intersection point is not on the flight segment S i on l S intersects with the rectangle ABCD, and the intersection point is not on the flight segment S i on the judgment method:

[0028] Case 1: When -a / 2 < x Ja < a / 2, (x i -x Ja )(x i+1 -x Ja ) > 0 (when x i ≠ x i+1 ) or (y i -y Jb )(y i+1 -y Jb ) > 0 (when x i = x i+1 ).

[0029] Case 2: When -b / 2 < y Jb < b / 2, (y i -y Jb )(y i+1 -y Jb ) > 0 (when y i ≠ y i+1 ) or (x i -x Ja )(x i+1 -x Ja ) > 0 (when y i = y i+1When).

[0030] Therefore, in Case 2, flight segment S i has no intersection with the rectangle and does not enter the non-safe area, that is, it is safe.

[0031] 2.3 Case 3: Points H i , H i+1 are both outside the rectangle ABCD, and l S intersects with the rectangle, and the intersection points are only on the flight segment S i on l S intersects with the rectangle ABCD, and the intersection points are only on the flight segment S i on the judgment method:[[]]

[0032] Case 1: When -a / 2 < x Ja < a / 2, (x i -x Ja )(x i+1 -x Ja ) < 0 (when x i ≠ x i+1 ) or (y i -y Jb )(y i+1 -y Jb ) < 0 (when x i = x i+1 ).

[0033] Case 2: When -b / 2 < y Jb < b / 2, (y i -y Jb )(y i+1 -y Jb ) < 0 (when y i ≠ y i+1 ) or (x i -x Ja )(x i+1 -x Ja ) < 0 (when y i = y i+1 ).

[0034] Therefore, in Case 3, flight segment S i has intersections with the rectangle and enters the non-safe area, that is, it is not safe.

[0035] 2.4 Case 4: Point H i is outside the rectangle ABCD, point H i+1 is on the rectangle ABCD, and S i has no intersection with the rectangle (except point H i+1 )

[0036] 1. Judgment method for point H i+1 on the rectangle ABCD

[0037] At this time, H i+1 is J a1 , J a2 one of them, or J b1 , J b2 one of them,

[0038] When -a / 2 < x i+1 < a / 2, y i+1 = b / 2 or y i+1 = -b / 2

[0039] When -b / 2 < y i+1 < b / 2, x i+1 = a / 2 or x i+1 = -a / 2

[0040] 2. Flight segment S i The method for judging that there is no intersection with rectangle ABCD (except point H i+1 )

[0041] Case 1: J a is another intersection point other than point H i+1 . When -a / 2 < x Ja < a / 2, (x i - x Ja )(x i+1 - x Ja ) > 0 (when x i ≠ x i+1 ) or (y i - y Jb )(y i+1 - y Jb ) > 0 (when x i = x i+1 ).

[0042] Case 2: J b is another intersection point other than point H i+1 . When -b / 2 < y Jb < b / 2, (y i - y Jb )(y i+1 - y Jb ) > 0 (when y i ≠ y i+1 ) or (x i - x Ja )(x i+1 - x Ja ) > 0 (when y i = y i+1 ).

[0043] Therefore, in Case 4, flight segment S i has no intersection with the rectangle (except point H i+1), not entering the non-safe area, i.e., safe.

[0044] 2.5 Case 5: Point H i Outside the rectangle ABCD, point H i+1 On the rectangle ABCD, and S i Has 1 intersection with the rectangle (except point H i+1 )

[0045] Flight segment S i Has 1 intersection with the rectangle ABCD (except point H i+1 ) The judgment method:

[0046] Case 1: J a Is not point H i+1 Another intersection, -a / 2 < x Ja < a / 2, (x i -x Ja )(x i+1 -x Ja ) < 0 (x i ≠ x i+1 When), or (y i -y Jb )(y i+1 -y Jb ) < 0 (x i = x i+1 When).

[0047] Case 2: J b Is not point H i+1 Another intersection, -b / 2 < y Jb < b / 2, (y i -y Jb )(y i+1 -y Jb ) < 0 (y i ≠ y i+1 When), or (x i -x Ja )(x i+1 -x Ja ) < 0 (y i = y i+1 When).

[0048] Therefore, in Case 5, the flight segment S i Has 1 intersection with the rectangle (except point H i+1 ), entering the non-safe area, i.e., not safe.

[0049] 2.6 Case 6: Point H i Outside the rectangle ABCD, point H i+1 Inside the rectangle ABCD

[0050] Point H i+1Judgment method within rectangle ABCD:

[0051]

[0052] Therefore, in case 6, flight segment S i has 1 intersection with the rectangle and enters the non-safe area, i.e., it is not safe.

[0053] 2.7 Case 7: Point H i is on rectangle ABCD, point H i+1 is outside rectangle ABCD, and S i has no intersection with the rectangle (except point H i )

[0054] The judgment method for flight segment S i having no intersection with rectangle ABCD (except point H i ) is the same as the method in 2.4.

[0055] Therefore, in case 7, flight segment S i has no intersection with the rectangle (except point H i ), and does not enter the non-safe area, i.e., it is safe.

[0056] 2.8 Case 8: Point H i is on rectangle ABCD, point H i+1 is outside rectangle ABCD, and S i has 1 intersection with the rectangle (except point H i )

[0057] The judgment method for flight segment S i having 1 intersection with rectangle ABCD (except point H i ) is the same as the method in 2.5.

[0058] Therefore, in case 8, flight segment S i has 1 intersection with the rectangle (except point H i ), and enters the non-safe area, i.e., it is not safe.

[0059] 2.9 Case 9: Points H i and H i+1 are both on rectangle ABCD

[0060] Flight segment S i has 2 intersections with rectangle ABCD.

[0061] Therefore, in case 9, flight segment S i enters the non-safe area, i.e., it is not safe.

[0062] 2.10 Case 10: Point H i is on rectangle ABCD, point H i+1 is inside rectangle ABCD

[0063] Flight segment S i has one intersection point with rectangle ABCD, which is point H i .

[0064] Therefore, in case 10, flight segment S i enters the non-safe area, that is, it is not safe.

[0065] 2.11 Case 11: Point H i is inside rectangle ABCD, point H i+1 is outside rectangle ABCD

[0066] Flight segment S i has one intersection point with rectangle ABCD.

[0067] Therefore, in case 11, flight segment S i enters the non-safe area, that is, it is not safe.

[0068] 2.12 Case 12: Point H i is inside rectangle ABCD, point H i+1 is on rectangle ABCD

[0069] Flight segment S i has one intersection point with rectangle ABCD, which is point H i+1 .

[0070] Therefore, in case 12, flight segment S i enters the non-safe area, that is, it is not safe.

[0071] 2.13 Case 13: Point H i is inside rectangle ABCD, point H i+1 is inside rectangle ABCD

[0072] Flight segment S i has no intersection point with rectangle ABCD.

[0073] Therefore, in case 13, flight segment S i enters the non-safe area, that is, it is not safe.

[0074] 2.14 Route l H set of non-safe flight segments

[0075] For the flight segments {S H , S 1 , …, S 2 , …, S n-1} on route l, after determining the safety situation one by one, the set of all non-safe flight segments is obtained.

[0076] The third step is to calculate the non-safe range of the route

[0077] The non-safe range of the flight route can be classified into two categories according to the safety conditions of each flight segment: The first category is the safe flight segment, where all flight routes of the segment are safe; the second category is the non-safe flight segment, where some flight routes of the segment are safe, that is, the part of the flight route that has not entered the non-safe area is safe, and the part of the flight route that has entered the non-safe area is not safe.

[0078] Among them: The first category corresponds to situations 1, 2, 4, and 7 in the second step; the second category corresponds to situations 3, 5, 6, 8, 9, 10, 11, 12, and 13 in the second step. Therefore, only by calculating the non-safe range of the flight segments corresponding to the 9 situations in the second category in this step can the non-safe range of the flight route be obtained.

[0079] 3.1 Non-safe flight segment S i Calculation of the non-safe range

[0080] 3.1.1 When the non-safe flight segment S i is in situation 3

[0081] The non-safe range of the flight segment S i is the flight route between the two intersection points of it and the rectangle ABCD. Let the two intersection points be H i1 , H i2 , that is, the line segment H i1 H i2 , as shown in Figure 2 :

[0082] According to the permutation and combination rules, when the flight segment S i intersects with different long sides and short sides of the rectangle ABCD, there can be 6 intersection point situations, that is, the line segment H i1 H i2 corresponds to 6 solution results:

[0083] J a1 J a2 、J a1 J b1 、J a1 J b2 、J a2 J b1 、J a2 J b2 、J b1 J b2

[0084] The above is the non-safe range of the flight segment S i .

[0085] Therefore, finding the coordinates of the intersection points J a1 , J a2 , J b1 , J b2 is sufficient. Taking J a1 , Jb1 For example, to solve for J a2 and J b2 the solution methods are the same.

[0086] The straight line l S The equation is divided into 3 cases:

[0087] 1. When x i ≠ x i+1 and y i ≠ y i+1 then

[0088]

[0089] At this time, for J a1 coordinates:

[0090]

[0091] For J b1 coordinates:

[0092]

[0093] 2. When x i = x i+1 then

[0094] x = x i

[0095] At this time, for J a1 coordinates:

[0096]

[0097] For J b1 coordinates: This case does not exist and there is no need to solve.

[0098] 3. When y i = y i+1 then

[0099] y = y i

[0100] At this time, for J a1 coordinates: This case does not exist and there is no need to solve.

[0101] For J b1 coordinates:

[0102]

[0103] 3.1.2 When the non-safe section S i is in case 5

[0104] The section S iThe non-safe range is the flight path between the two intersections of it and rectangle ABCD. Let the two intersections be H i1 and H i2 , that is, line segment H i1 H i2 , as shown in Figure 3 :

[0105] Among them, intersection point H i2 is H i+1 . After permutation and combination, line segment H i1 H i+1 corresponds to 4 solution results:

[0106] J a1 H i+1 、J a2 H i+1 、J b1 H i+1 、J b2 H i+1

[0107] The above is the non-safe range of flight segment S i .

[0108] Therefore, find the coordinates of intersection points J a1 、J a2 、J b1 、J b2 . The solution method is the same as that in 3.1.1.

[0109] 3.1.3 When the non-safe flight segment S i is in case 6

[0110] The non-safe range of flight segment S i is the flight path from one intersection of it and rectangle ABCD to point H i+1 . Let the intersection point be H i1 , that is, line segment H i1 H i+1 , as shown in Figure 4 :

[0111] Similar to 3.1.2, after permutation and combination, line segment H i1 H i+1 corresponds to 4 solution results:

[0112] J a1 H i+1 、J a2 H i+1 、J b1 H i+1 、J b2 H i+1

[0113] The above is the flight segment S iThe non-safe range.

[0114] 3.1.4 When the non-safe flight segment S i is in case 8

[0115] The flight segment S i The non-safe range is the flight path between the two intersection points of it and the rectangle ABCD. Let the two intersection points be H i1 、H i2 That is, the line segment H i1 H i2 For example Figure 5 :

[0116] Among them, the intersection point H i1 is H i After permutation and combination, the line segment H i H i2 corresponds to 4 solution results:

[0117] H i J a1 、H i J a2 、H i J b1 、H i J b2

[0118] The above is the non-safe range of the flight segment S i The non-safe range.

[0119] 3.1.5 When the non-safe flight segment S i is in case 9

[0120] The flight segment S i The non-safe range is the flight path from the point H i to H i+1 That is, the line segment H i H i+1 For example Figure 6 :

[0121] 3.1.6 When the non-safe flight segment S i is in case 10

[0122] The flight segment S i The non-safe range is the flight path from the point H i to H i+1 That is, the line segment H i H i+1 For example Figure 7 :

[0123] 3.1.7 When the non-safe flight segment S i is in case 11

[0124] The flight segment S iThe non-safe range is point H i to S i and the flight path between one intersection point of rectangle ABCD. Let the intersection point be H i1 , which is line segment H i H i1 , such as Figure 8 :

[0125] Similar to 3.1.4, after permutation and combination, line segment H i H i1 corresponds to 4 solution results:

[0126] H i J a1 , H i J a2 , H i J b1 , H i J b2

[0127] The above is the non-safe range of flight segment S i .

[0128] 3.1.8 When the non-safe flight segment S i is in case 12

[0129] The non-safe range of flight segment S i is the flight path between point H i to H i+1 , which is line segment H i H i+1 , such as Figure 9 :

[0130] 3.1.9 When the non-safe flight segment S i is in case 13

[0131] The non-safe range of flight segment S i is the flight path between point H i to H i+1 , which is line segment H i H i+1 , such as Figure 10 :

[0132] 3.2 The entire non-safe range of flight path l H After using the calculation model to calculate the non-safe range of each non-safe flight segment on flight path l

[0133] one by one, the non-safe ranges of all non-safe flight segments are the entire non-safe range of the flight path. H

[0134] The beneficial effects of the present invention are:

[0135] ​The calculation model proposed by the present invention can conveniently and quickly calculate the non-safe range on the shipping route, and can be used as an auxiliary calculation tool for ship navigation operation-related systems, so as to better assist navigators in local modification or re-formulation of the shipping route and other work. BRIEF DESCRIPTION OF THE DRAWINGS

[0136] Figure 1 It is a schematic diagram of the coordinate system xOy of the present invention.

[0137] Figure 2 It is a schematic diagram of Case 3 of the present invention.

[0138] Figure 3 It is a schematic diagram of Case 5 of the present invention.

[0139] Figure 4 It is a schematic diagram of Case 6 of the present invention.

[0140] Figure 5 It is a schematic diagram of Case 8 of the present invention.

[0141] Figure 6 It is a schematic diagram of Case 9 of the present invention.

[0142] Figure 7 It is a schematic diagram of Case 10 of the present invention.

[0143] Figure 8 It is a schematic diagram of Case 11 of the present invention.

[0144] Figure 9 It is a schematic diagram of Case 12 of the present invention.

[0145] Figure 10 It is a schematic diagram of Case 13 of the present invention.

[0146] Figure 11 It is a schematic diagram of the coordinate system of the model of the present invention and the shipping route l of Embodiment 1 1 Schematic diagram. DETAILED DESCRIPTION OF THE INVENTION

[0147] To make the objectives, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0148] Example 1

[0149] A method for calculating the non-safe range of a ship's shipping route includes the following steps:

[0150] Step 1: Establish the coordinate system of the model

[0151] As Figure 11 , establish a plane rectangular coordinate system xOy; assume the non-safe area is approximately a rectangular area, denoted as rectangle ABCD, with its center point O, a length of 40 km, and a width of 20 km; take point O as the origin of the coordinate system, the true north direction as the positive direction of the y-axis, and rotate 90° clockwise as the positive direction of the x-axis.

[0152] Actually draw the ship route l 1 , the positions of the two endpoints of the route and each turning point are respectively denoted as {H 1 , H 2 , …, H 7}}, and each turning point divides the route into 6 segments, denoted as {S 1 , S 2 , …, S 6}}. Among them, the coordinates of each turning point are as follows: H 1 (-31.65, -22.5), H 2 (-22.99, -17.5), H 3 (-18.66, -20.0), H 4 (-10.0, -5.0), H 5 (0.0, -5.0), H 6 (10.0, -15.0), H 7 (24.14, -0.86).

[0153] Step 2: Determine the safety conditions of the segments {S 1 , S 2 , …, S 6}}

[0154] 1. Safety condition of segment S 1

[0155] Position relationship between point H 1 and rectangle ABCD:

[0156]

[0157] It is concluded that point H 1 is outside rectangle ABCD.

[0158] Position relationship between point H 2 and rectangle ABCD:

[0159]

[0160] It is concluded that point H 2 is outside rectangle ABCD.

[0161] Next, further determine the straight line l​S Intersection with rectangle, l S The equation is:

[0162] y = 0.58(x + 31.65) - 22.5

[0163] Its intersection coordinates with the straight lines where the long side and short side of the rectangle are located (l AD 、l BC 、l AB 、l DC ) are as follows:

[0164] J a1 (24.38, 10)

[0165] J b1 (-20, -15.74)

[0166] J a2 (-10.1, -10)

[0167] J b2 (20, 7.46)

[0168] Among them, x Ja1 = 24.38 > 20, y Jb1 = -15.74 < -10, that is, J a1 、J b1 are outside the rectangle and do not need to be considered. Only judge J a2 、J b2 :

[0169] Case 1: x Ja2 = -10.1, -20 < x Ja2 < 20, and

[0170] (x 1 - x Ja2 )(x 2 - x Ja2 ) = (-31.65 + 10.1)(-22.99 + 10.1) = -98.54 > 0 (when x i ≠ x i+1 )

[0171] Case 2: y Jb2 = 7.46, -10 < y Jb2 < 10, and

[0172] (y 1 - y Jb2 )(y 2 - y Jb2 ) = (-22.5 - 7.46)(-17.5 - 7.46) = 747.8 > 0 (when y i ≠ y i+1When)

[0173] Therefore, flight segment S 1 The safety situation corresponds to Case 2 and does not enter the non-safe area, that is, it is safe.

[0174] 2. The safety situation of flight segment S 2 The safety situation

[0175] Point H 2 Is outside the rectangle ABCD;

[0176] Point H 3 The positional relationship with the rectangle ABCD:

[0177] y 3 =-20 < -b / 2 = -10

[0178] It is concluded that point H 3 Is outside the rectangle ABCD.

[0179] Next, further determine the intersection situation of the straight line l S With the rectangle. The equation of l S Is:

[0180] y = -0.58(x + 22.99) - 17.5

[0181] Its intersection coordinates with the straight lines where the long side and short side of the rectangle are located (l AD 、l BC 、l AB 、l DC ) are as follows:

[0182] J a1 (-70.4, 10)

[0183] J b1 (-20, -19.23)

[0184] J a2 (-35.92, -10)

[0185] J b2 (20, -42.43)

[0186] After judgment:

[0187]

[0188] That is, J a1 、J b1 、J a2 、J b2 Are all outside the rectangle.

[0189] Therefore, the safety situation of flight segment S 2 The safety situation corresponds to Case 1 and does not enter the non-safe area, that is, it is safe.

[0190] 3. Safety condition of flight segment S 3

[0191] Point H 3 is outside the rectangle ABCD;

[0192] Point H 4 Position relationship with rectangle ABCD:

[0193]

[0194] It is concluded that point H 4 is inside the rectangle ABCD.

[0195] Therefore, the safety condition of flight segment S 3 corresponds to situation 6, entering the non - safe area, that is, unsafe.

[0196] 4. Safety condition of flight segment S 4

[0197] Point H 4 is inside the rectangle ABCD;

[0198] Point H 5 Position relationship with rectangle ABCD:

[0199]

[0200] It is concluded that point H 5 is inside the rectangle ABCD.

[0201] Therefore, the safety condition of flight segment S 4 corresponds to situation 13, entering the non - safe area, that is, unsafe.

[0202] 5. Safety condition of flight segment S 5

[0203] Point H 5 is inside the rectangle ABCD;

[0204] Point H 6 Position relationship with rectangle ABCD:

[0205] y 6 =-15 < -10

[0206] It is concluded that point H 6 is outside the rectangle ABCD.

[0207] Therefore, the safety condition of flight segment S 5 corresponds to situation 11, entering the non - safe area, that is, unsafe.

[0208] 6. Safety condition of flight segment S 6 ​​​​

[0209] Point H 6 is outside the rectangle ABCD;

[0210] Point H 7 The positional relationship with the rectangle ABCD:

[0211] x 7 = 24.14 > 20

[0212] It is concluded that point H 7 is outside the rectangle ABCD.

[0213] Next, further determine the intersection situation of the straight line l S with the rectangle. The equation of l S is:

[0214] y = (x - 10) - 15

[0215] Its intersection coordinates with the straight lines where the long side and short side of the rectangle are located (l AD , l BC , l AB , l DC ) are as follows:

[0216] J a1 (35, 10)

[0217] J b1 (-20, -45)

[0218] J a2 (15, -10)

[0219] J b2 (20, -5)

[0220] Among them, x Ja1 = 35 > 20, y Jb1 = -45 < -10, that is, J a1 , J b1 are outside the rectangle and do not need to be considered. Only judge J a2 , J b2 :

[0221] Case 1: x Ja2 = 15, -20 < x Ja2 < 20, and

[0222] (x 6 - x Ja2 )(x 7 - x Ja2 ) = (10 - 15)(24.14 - 15) = -45.7 < 0 (when x i ≠ x i+1 )

[0223] Case 2: y Jb2 =-5, -10 < y Jb2 < 10, and

[0224] (y 6 -y Jb2 )(y 7 -y Jb2 ) = (-15 + 5)(-0.86 + 5) = -41.4 < 0 (y i ≠ y i+1 )

[0225] Therefore, flight segment S 7 's safety condition corresponds to Case 3 and enters the non - safe area, i.e., it is not safe.

[0226] 7. Route l 1 The set of non - safe flight segments

[0227] For the flight segments {S 1 , S 1 , …, S 2 , …, S 6} on route l, the determination of safety conditions has been completed one by one. Therefore, the set of all non - safe flight segments is {S 3 , S 4 , S 5 , S 6}.

[0228] Step 3: Calculate the non - safe range of the route

[0229] 3.1 Calculation of the non - safe range of non - safe flight segment S i Calculation of the non - safe range

[0230] 1. Calculation of the non - safe range of flight segment S 3 Calculation of the non - safe range

[0231] Flight segment S 3 corresponds to Case 6, and the non - safe range is line segment H 31 H 4 .

[0232] From the technical solution and examples, the intersection point of line segment H 31 H 4 and the rectangle is J a2 . Therefore, H 31 H 4 is J a2 H 4 . Solving for the coordinates of J a2 is sufficient.

[0233] When x 3 ≠ x 4 , y 3 ≠ y 4 ), straight line lS The equation is

[0234] y = 1.73(x + 18.66) - 20

[0235] At this time, J a2 The formula for solving the coordinates is

[0236]

[0237] Therefore, J a2 The coordinates are:

[0238]

[0239] 2. Non - safety range calculation of flight segment S 4

[0240] Flight segment S 4 Corresponding to case 13, the non - safety range is line segment H 4 H 5 .

[0241] 3. Non - safety range calculation of flight segment S 5

[0242] Flight segment S 5 Corresponding to case 11, the non - safety range is line segment H 51 H 6 .

[0243] From the technical solution and examples, it can be seen that the intersection point of line segment H 51 H 6 and the rectangle is J a2 , so H 51 H 6 is J a2 H 4 , just solve the coordinates of J a2 .

[0244] When x 5 ≠ x 6 , y 5 ≠ y 6 , the equation of line l S is

[0245] y = -(x - 0) - 5

[0246] At this time, J a2 The formula for solving the coordinates is

[0247]

[0248] Therefore, J a2 The coordinates are:

[0249]

[0250] 4. Flight segment S 6 Calculation of the non - safe range

[0251] Flight segment S 6 For Case 3, the non - safe range is line segment H 61 H 62 .

[0252] From the technical solution and the example, it can be seen that the intersection points of line segment H 61 H 62 and the rectangle are J a2 、J b2 , so H 61 H 62 is J a2 J b2 , and solving for the coordinates of J a2 、J b2 is sufficient.

[0253] When x 6 ≠x 7 、y 6 ≠y 7 at this time, the equation of line l S is,[[]]

[0254] y=(x - 10)-15

[0255] At this time, the coordinate solving formulas for J a2 、J b2 are respectively,[[]]

[0256]

[0257] Therefore, the coordinates of J a2 are:[[]]

[0258]

[0259] J b2 The coordinates are:[[]]

[0260]

[0261] 3.2 Route l 1 All non - safe ranges

[0262] Using the calculation model, the non - safe ranges of each non - safe flight segment on route l 1 have been calculated one by one, and the total non - safe range of the route is obtained as H 31 H 4 、H 4 H 5 、H 51 H 6 、H 61 H62 .

[0263] The coordinates of each point are:

[0264] H 31 (-12.89, -10.0)

[0265] H 4 (-10.0, -5.0)

[0266] H 5 (0.0, -5.0)

[0267] H 51 (5.0, -10)

[0268] H 6 (10.0, -15.0)

[0269] H 61 (15.0, -10.0)

[0270] H 62 (20.0, -5.0).

Claims

1. A method for calculating the non-safe range of a ship's route, characterized in that, it includes the following steps: The first step is to establish the coordinate system of the model Establish a plane rectangular coordinate system xOy; assume that the non-safe area is approximately a rectangular area, denoted as rectangle ABCD, with its center point O, length a, and width b; take point O as the origin of the coordinate system, the due north direction as the positive direction of the y-axis, and rotate 90° clockwise as the positive direction of the x-axis; Let the ship's route be \(l\). H , and the positions of the two endpoints and each turning point of the route are denoted as \(\{H 1 , H 2 , \cdots, H n \}\). Each turning point divides the route into \(n - 1\) segments, denoted as \(\{S 1 , S 2 , \cdots, S n-1 \}\). For the segment \(S i , its two endpoints are \(H i \) and \(H i+1 , i = 1, 2, \cdots, n - 1;\) Step 2, determine flight segment S i Safety situation Flight segment S i The two endpoints of i are H i+1 , H i , according to the positional relationship between points H i+1 , H i and the rectangular dangerous area ABCD, the safety of flight segment S can be determined corresponding to the following 13 cases; 2.1 Case 1: Point H i and H i+1 are both outside the rectangle ABCD, and the flight segment S i wherein the straight line does not intersect with the rectangle 1. Point H i and H i+1 Method for judging outside rectangle ABCD 2. Method for determining non-intersection with rectangle ABCD Straight line The equation is: When x i ≠ x i+1 , y i ≠ y i+1 then y = k(x - x i ) + y i When x i = x i+1 then x = x i When y i = y i+1 then y = yi The straight line \(l\) where the long side \(AD\) of the rectangle lies AD The equation is \(y = \frac{b}{2}\), and the straight line \(l\) where the long side \(BC\) lies BC The equation is \(y = -\frac{b}{2}\); the straight line \(l\) where the short side \(AB\) lies AB The equation is \(x = -\frac{a}{2}\), and the straight line \(l\) where the short side \(DC\) lies DC The equation is \(x = \frac{a}{2}\); Let The intersection point with the straight line where the long side of the rectangle is located is J a , where the intersection point with AD is J a1 , and the intersection point with BC is J a2 ; The intersection point with the straight line where the short side of the rectangle is located is J b , where the intersection point with AB is J b1 , and the intersection point with DC is J b2 ; The judgment method is as follows: Therefore, in Case 1, flight segment S i has no intersection with the rectangle and does not enter the non-safe area, i.e., it is safe; 2.2 Case 2: Point H i , H i+1 are both outside the rectangle ABCD, and intersects with the rectangle, and the intersection point is not on the flight segment S i above intersects with the rectangle ABCD, and the intersection point is not on the flight segment S i above. The judgment method is as follows: Case 1: -a / 2 < x Ja < a / 2, (x i -x Ja )(x i+1 -x Ja ) > 0, where x i ≠ x i+1 or (y i -y Jb )(y i+1 -y Jb ) > 0, where x i = x i+1 ; Case 2: -b / 2 < y Jb < b / 2, (y i -y Jb )(y i+1 -y Jb ) > 0, where y i ≠ y i+1 or (x i -x Ja )(x i+1 -x Ja ) > 0, where y i = y i+1 ; Therefore, in Case 2, the flight segment S i has no intersection with the rectangle and does not enter the non-safe area, i.e., it is safe; 2.3 Case 3: Point H i , H i+1 are both outside the rectangle ABCD, and intersects with the rectangle, and the intersection points are only on the flight segment S i above intersects with the rectangle ABCD, and the judgment method for the intersection points only on the flight segment S i above is as follows: Case 1: -a / 2 < x Ja < a / 2, (x i -x Ja )(x i+1 -x Ja ) < 0, where x i ≠ x i+1 or (y i -y Jb )(y i+1 -y Jb ) < 0, where x i = x i+1 ; Case 2: -b / 2 < y Jb < b / 2, (y i -y Jb )(y i+1 -y Jb ) < 0, where y i ≠ y i+1 or (x i -x Ja )(x i+1 -x Ja ) < 0, where y i = y i+1 ; Therefore, in Case 3, the flight segment S i intersects with the rectangle and enters the non-safe area, i.e., it is not safe; 2.4 Case 4: Point H i Outside the rectangle ABCD, point H i+1 On the rectangle ABCD, and S i Has no intersection with the rectangle except point H i+1 No intersection 1. Point H i+1 Judgment method on rectangle ABCD At this time, H i+1 is one of J a1 and J a2 or one of J b1 and J b2 or one of them. When -a / 2 < x i+1 < a / 2, y i+1 = b / 2 or y i+1 = -b / 2 When -b / 2 < y i+1 < b / 2, x i+1 = a / 2 or x i+1 = -a / 2 2. Flight segment S i The judgment method for having no intersection points with rectangle ABCD except point H i+1 ​ Case 1: J a is another intersection point of non-point H i+1 When -a / 2 < x Ja < a / 2, (x i - x Ja )(x i+1 - x Ja ) > 0, where x i ≠ x i+1 or (y i - y Jb )(y i+1 - y Jb ) > 0, where x i = x i+1 ; Case 2: J b is another intersection point of non-point H i+1 , when -b / 2 < y Jb < b / 2, (y i - y Jb )(y i+1 - y Jb ) > 0, where y i ≠ y i+1 or (x i - x Ja )(x i+1 - x Ja ) > 0, where yi = yi +1 ; Therefore, in case 4, flight segment S i has no intersection with the rectangle except point H i+1 and does not enter the non-safe area, that is, it is safe; 2.5 Case 5: Point H i Outside the rectangle ABCD, point H i+1 On the rectangle ABCD, and S i With the rectangle except point H i+1 Has 1 intersection point Flight segment S i Except for point H with rectangle ABCD i+1 Judgment method with one intersection point: Case 1: J a is another intersection point of non-point H i+1 When -a / 2 < x Ja < a / 2, (x i - x Ja )(x i+1 - x Ja ) < 0, where x i ≠ x i+1 or (y i - y Jb )(y i+1 - y Jb ) < 0, where x i = x i+1 ; Case 2: J b is another intersection point of non-point H i+1 When -b / 2 < y Jb < b / 2, (y i - y Jb )(y i+1 - y Jb ) < 0, where y i ≠ y i+1 or (x i - x Ja )(x i+1 - x Ja ) < 0, where yi = yi +1 ; Therefore, in case 5, flight segment S i has one intersection point with the rectangle except point H i+1 and enters the non-safe area, which means it is not safe; 2.6 Case 6: Point H i Outside the rectangle ABCD, point H i+1 Inside the rectangle ABCD Point H i+1 Judgment method within rectangle ABCD: Therefore, in case 6, flight segment S i has one intersection with the rectangle and enters the non-safe area, i.e., it is not safe; 2.7 Case 7: Point H i On rectangle ABCD, point H i+1 Outside rectangle ABCD, and S i Has no intersection with the rectangle except point H i No intersection points Flight segment S i For the judgment method of having no intersection points with rectangle ABCD except point H i It is the same as the method in 2.4; Therefore, in case 7, the flight segment S i has no intersection with the rectangle except point H i and does not enter the non-safe area, that is, it is safe; 2.8 Case 8: Point H i On rectangle ABCD, point H i+1 Outside rectangle ABCD, and S i Has 1 intersection point with the rectangle except point H i Has 1 intersection point Flight segment S i Except for point H with rectangle ABCD i The judgment method with one intersection point is the same as the method in 2.5; Therefore, in case 8, flight segment S i has one intersection point with the rectangle except point H i and enters the non-safe area, that is, it is not safe; 2.9 Case 9: Point H i , H i+1 are both on rectangle ABCD Flight segment S i There are two intersections with rectangle ABCD; Therefore, in case 9, flight segment S i enters the non-safe area, i.e., it is not safe; 2.10 Case 10: Point H i On rectangle ABCD, point H i+1 Inside rectangle ABCD Flight segment S i It has one intersection point with rectangle ABCD, namely point H i ; Therefore, in case 10, flight segment S i enters the non-safe area, i.e., it is not safe; 2.11 Case 11: Point H i Inside rectangle ABCD, point H i+1 Outside rectangle ABCD Flight segment S i There is 1 intersection point with rectangle ABCD; Therefore, in case 11, flight segment S i enters the non-safe area, i.e., it is not safe; 2.12 Case 12: Point H i Inside rectangle ABCD, point H i+1 On rectangle ABCD Flight segment S i It has one intersection point with rectangle ABCD, namely point H i+1 ; Therefore, in case 12, flight segment S i enters the non-safe area, that is, it is not safe; 2.13 Case 13: Point H i Inside rectangle ABCD, point H i+1 Inside rectangle ABCD Flight segment S i Has no intersection with rectangle ABCD; Therefore, in Case 13, flight segment S i enters the non-safe area, i.e., it is not safe; 2.14 Route l H Set of non-safe flight segments For route l H on the flight segments {S 1 , S 2 , …, S n-1}, after determining the safety situation for each one, the set of all non-safe flight segments can be obtained; The third step is to calculate the non-safe range of the route The non-safe range of the route can be divided into two categories according to the safety conditions of each section: The first category is the safe section, where all the routes of the section are safe; the second category is the non-safe section, where part of the route of the section is safe, that is, the part of the route that does not enter the non-safe area is safe, and the part of the route that enters the non-safe area is not safe; Among them: The first category corresponds to situations 1, 2, 4, and 7 in the second step; the second category corresponds to situations 3, 5, 6, 8, 9, 10, 11, 12, and 13 in the second step; therefore, in this step, only the non-safe range of the sections corresponding to the 9 situations in the second category needs to be calculated to obtain the non-safe range of the route; 3.1 Non-safe flight segment S i Calculation of the non-safe range; 3.2 Route l H All non-safe areas Using a computational model, for each non-safe section on route l H after calculating the non-safe range one by one, the non-safe range of all non-safe sections is the entire non-safe range of the route.

2. A method for calculating the non-safe range of a ship's route according to claim 1, characterized in that, The non-safe range calculation of the non-safe flight segment S in step 3.1 described above i is carried out as follows: 3.1.1 When the non-safe flight segment S i is in Case 3 Flight segment S i The non-safe range is the flight path between the two intersection points of it and rectangle ABCD. Let the two intersection points be H i1 、H i2 That is, the line segment H i1 H i2 ; According to the permutation and combination rules, flight segment S i intersects with different long sides and short sides of rectangle ABCD, and there can be 6 intersection cases, namely line segment H i1 H i2 corresponding to 6 solution results: J a1 J a2 、J a1 J b1 、J a1 J b2 、J a2 J b1 、J a2 J b2 、J b1 J b2 The above is the non-safe range of flight segment S i ; Therefore, find the intersection point J a1 , J a2 , J b1 , J b2 coordinates are sufficient. Taking J a1 , J b1 as an example for solution, the solutions for J a2 , J b2 are the same; Straight line l Si The equation is divided into three cases:

1. When x i ≠ x i+1 , y i ≠ y i+1 , then y = k(x - x i ) + y i At this time, J a1 Coordinates: J b1 Coordinates:

2. When x i = x i+1 at that time x = x i At this time, J a1 Coordinates: J b1 Coordinates: This situation does not exist and there is no need to solve it; 3. When y i = y i+1 then y = yi At this time, J a1 Coordinates: This situation does not exist and there is no need to solve it; J b1 Coordinates: 3.1.2 When the non-safe flight segment S i is in Case 5 Flight segment S i The non-safe range is the flight path between the two intersection points of it and rectangle ABCD. Let the two intersection points be H i1 and H i2 , that is, line segment H i1 H i2 ; wherein, Intersection point H i2 is H i+1 , after permutation and combination, line segment H i1 H i+1 corresponds to 4 solution results: J a1 H i+1 、J a2 H i+1 、J b1 H i+1 、J b2 H i+1 The above is the non-safe range of flight segment S i ; Therefore, find the intersection point J a1 , J a2 , J b1 , J b2 coordinates. The solution method is the same as that in 3.1.1; 3.1.3 When the non-safe flight segment S i is in Case 6 Flight segment S i The non-safe range is the flight path from one intersection point of it and rectangle ABCD to point H i+1 Let the intersection point be H i1 , which is the line segment H i1 H i+1 ; Same as 3.1.2, after permutation and combination, line segment H i1 H i+1 Corresponding to the results of 4 solutions: J a1 H i+1 、J a2 H i+1 、J b1 H i+1 、J b2 H i+1 The above is the non-safe range of flight segment S i ; 3.1.4 When the non-safe flight segment S i is in Case 8 Flight segment S i The non-safe range is the flight path between the two intersection points of it and rectangle ABCD. Let the two intersection points be H i1 、H i2 That is, the line segment H i1 H i2 ; Among them, the intersection point H i1 is H i , after permutation and combination, the line segment H i H i2 corresponds to 4 solution results: H i J a1 and H i J a2 and H i J b1 and H i J b2 The above is the non-safe range of flight segment S i ; 3.1.5 When the non-safe flight segment S i is in Case 9 Flight segment S i The non-safe range is the route between point H i and H i+1 That is, the line segment H i H i+1 ; 3.1.6 When the non-safe flight segment S i is in case 10 Flight segment S i The non-safe range is the route between point H i and H i+1 That is, the line segment H i H i+1 ; 3.1.7 When the non-safe flight segment S i is in Case 11 Flight segment S i The non-safe range of i from point H i to an intersection point between S i1 and rectangle ABCD. Let the intersection point be H i H i1 ; Same as 3.1.4, after permutation and combination, line segment H i H i1 Corresponding to 4 solution results: H i J a1 、H i J a2 、H i J b1 、H i J b2 The above is the non-safe range of flight segment S i ; 3.1.8 When the non-safe flight segment S i is in Case 12 Flight segment S i The non-safe range of i is the flight path between point H i+1 and H i H i+1 ; 3.1.9 When the non-safe flight segment S i is in case 13 Flight segment S i The non-safe range of i from point H i+1 to H i H i+1 .

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