Ship steering assistance device and ship steering assistance program

Abstract

To provide a navigation support device and a navigation support program capable of determining a propulsion command value for a vessel so that obstacles are flexibly and quantitatively evaded.SOLUTION: A navigation support device for a vessel including at least one propeller includes a computing unit and a display for displaying a result calculated by the computing unit. The computing unit acquires own vessel information regarding the position, course, and speed of the vessel, and obstacle information regarding the position, course, and speed of the obstacle in a prescribed range determined based on the position and / or attitude of the vessel, calculates a range of command values estimated to have an occurrence of possibility of having the vessel come into contact with an obstacle regarding the size and direction of the propulsion force the vessel can output from the own vessel information and the obstacle information as a dangerous propulsion command range, and displays the dangerous propulsion command value range on a display screen of the display.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present disclosure relates to a ship-steering assist device and a ship-steering assist program for a ship including at least one propulsion unit. [Background technology]

[0002] Because bays are crowded with many ships and the environment is constantly changing, maneuvering within a bay, especially when approaching or leaving a berth, is generally difficult. To prevent collisions with other ships, quays, and other obstacles, ships must be able to make quick and accurate maneuvering decisions.

[0003] The following Patent Document 1 discloses a method for assisting ship maneuvering, in which, when it is determined that there is a risk of collision with an obstacle, one of a plurality of preset avoidance command patterns is selected and displayed on a display device. More specifically, in Patent Document 1, a ship maneuvering pattern (maintain speed, turn starboard, or decelerate) is predefined depending on which of a plurality of areas defined as an angular range centered on the ship in which the obstacle (other ship) is located. For example, if the obstacle is located in Area 1 to the right front of the ship, a starboard turn is selected as the avoidance command pattern. Also, for example, if the obstacle is located in Area 2 to the right of the ship, a deceleration is selected as the avoidance command pattern. In this way, conventional ship maneuvering assistance devices for collision avoidance present optimal operation content for avoiding an obstacle based on the positional relationship between the obstacle and the ship. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2016-049903 Summary of the Invention [Problem to be solved by the invention]

[0005] However, in the above-described configuration, it is not clear whether there is a risk of collision with an obstacle if the vessel is maneuvered in a manner other than the optimal maneuver described above. For example, if the vessel helmsman finds an obstacle on the route based on the presented maneuver that was not detected by the obstacle detection sensor, the vessel helmsman must maneuver the vessel using a different maneuver from the presented maneuver. However, in the above-described conventional configuration, it is not clear how to change the maneuver (how to change course). Furthermore, in the configuration of Patent Document 1, only a maneuvering pattern based on qualitative maneuvering is predetermined, and quantitative maneuvering amounts (magnitude and direction of the vessel's thrust) for avoiding collisions are not presented. Therefore, in order to appropriately avoid collisions, the vessel helmsman needs to understand the vessel's performance (inertial force, etc.).

[0006] Therefore, an object of the present disclosure is to provide a ship-maneuvering assistance device and a ship-maneuvering assistance program that can determine a thrust command value for a ship so as to avoid obstacles flexibly and quantitatively. [Means for solving the problem]

[0007] A ship maneuvering assistance device in one aspect of the present disclosure is a ship maneuvering assistance device for a ship including at least one propulsion unit, and is equipped with a calculator and a display that displays the results of calculations performed by the calculator, wherein the calculator acquires own ship information regarding the position, course, and speed of the ship, and obstacle information regarding the position, course, and speed of an obstacle within a predetermined range determined based on the position and / or attitude of the ship, calculates from the own ship information and the obstacle information a range of command values for the magnitude and direction of thrust that the ship can output that are estimated to result in the ship possibly coming into contact with the obstacle, as the dangerous thrust command value range, and displays the dangerous thrust command value range on the display screen of the display.

[0008] In addition, a ship maneuvering assistance program in another aspect of the present disclosure is a ship maneuvering assistance program for a ship including at least one propulsion unit, which causes a computer to function as an information acquisition unit that acquires own ship information regarding the position, course, and speed of the ship, and obstacle information regarding the position, course, and speed of an obstacle within a predetermined range determined based on the position and / or attitude of the ship, a dangerous thrust command value range calculation unit that calculates, from the own ship information and the obstacle information, a range of command values for the magnitude and direction of thrust that can be output by the ship that are estimated to result in a possibility of contact with the obstacle, as a dangerous thrust command value range, and a dangerous thrust command value range display unit that displays the dangerous thrust command value range on a display screen of the computer.

[0009] According to the ship maneuvering assistance device and ship maneuvering assistance program configured as described above, the range of command values estimated to result in contact with an obstacle, among the magnitude and direction of thrust that the ship can output based on the ship information and obstacle information, is displayed on the display screen as a dangerous thrust command value range. Therefore, a user such as a ship helmsman can freely determine operation content from combinations of thrust magnitudes and directions that the ship can output, while taking into account the dangerous thrust command value range displayed on the display screen. In this way, according to the configuration described above, it is possible to provide the ship helmsman with suggestions for determining operation content to flexibly and quantitatively avoid obstacles.

[0010] In addition, a ship maneuvering assistance device in another aspect of the present disclosure is a ship maneuvering assistance device for a ship including at least one propulsion unit, comprising a computing unit and a display unit that displays the results of calculations performed by the computing unit, wherein the computing unit acquires own ship information relating to the position, course, and speed of the ship, and obstacle information relating to the position, course, and speed of an obstacle within a predetermined range determined based on the position and / or attitude of the ship, calculates a dangerous thrust command value range as a range of command values for the magnitude and direction of thrust that the ship can output, which are estimated to result in a possibility of contacting the obstacle, from the own ship information and the obstacle information, determines whether a current command value for the magnitude and direction of thrust of the ship is within the dangerous thrust command value range, and if the current command value is within the dangerous thrust command value range, corrects the current command value to a command value outside the dangerous thrust command value range.

[0011] In addition, a ship maneuvering assistance program in another aspect of the present disclosure causes a computer to function as an information acquisition unit that acquires own ship information related to the position, course, and speed of the ship, and obstacle information related to the position, course, and speed of an obstacle within a predetermined range determined based on the position and / or attitude of the ship, a dangerous thrust command value range calculation unit that calculates, from the own ship information and the obstacle information, a range of command values for the magnitude and direction of thrust that the ship can output, which are estimated to result in a possibility of contacting the obstacle, as a dangerous thrust command value range, a determination unit that determines whether a current command value for the magnitude and direction of thrust of the ship is included in the dangerous thrust command value range, and a command value correction unit that, if the current command value is included in the dangerous thrust command value range, corrects the current command value to a command value outside the dangerous thrust command value range.

[0012] According to the ship maneuvering assistance device and ship maneuvering assistance program configured as described above, the range of command values that are estimated to result in the possibility of contact with an obstacle, among the magnitude and direction of thrust that the ship can output based on the ship information and obstacle information, is calculated as the dangerous thrust command value range. Furthermore, if the ship's current command value falls within the dangerous thrust command value range, the current command value is corrected to a command value outside the dangerous thrust command value range. Therefore, regardless of the ship helmsman's operation amount, the ship can be maneuvered using a command value that falls outside the dangerous thrust command value range. Moreover, the ship helmsman can freely determine the operation amount outside the dangerous thrust command value range. Therefore, the ship's thrust command value can be determined to avoid obstacles flexibly and quantitatively. [Effects of the Invention]

[0013] According to the present disclosure, it is possible to determine a thrust command value for a vessel so as to avoid obstacles flexibly and quantitatively. [Brief explanation of the drawings]

[0014] [Figure 1] FIG. 1 is a block diagram showing a schematic configuration of a ship maneuvering assistance device according to an embodiment of the present disclosure. [Figure 2] FIG. 2 is an image diagram of the process of extracting a dangerous thrust command value in this embodiment. [Figure 3] FIG. 3 is a diagram showing an example of the positional relationship between a ship and an obstacle. [Figure 4] FIG. 4 is a diagram for explaining a certain ship maneuvering pattern. [Figure 5] FIG. 5 is a diagram showing an example of a manner in which the time change of the dangerous thrust command value range is displayed on the display screen in this embodiment. [Figure 6] FIG. 6 is a diagram showing another example of a manner in which the time change of the dangerous thrust command value range is displayed on the display screen in this embodiment. [Figure 7] FIG. 7 is a diagram showing an example of a display screen in another embodiment. [Figure 8]FIG. 8 is a block diagram showing a schematic configuration of a ship maneuvering assist device according to a modified example of an embodiment of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0015] Hereinafter, an embodiment of the present disclosure will be described in detail with reference to the drawings. Note that, in the following, the same or corresponding elements will be denoted by the same reference numerals throughout the drawings, and redundant description thereof will be omitted.

[0016] FIG. 1 is a block diagram showing a schematic configuration of a ship maneuvering assistance device according to an embodiment of the present disclosure. The ship maneuvering assistance device 1 shown in FIG. 1 includes an input device 2, a memory device 3, a computing device 4, and a display device 5. The components 1 to 5 communicate data with each other via a bus 6. The ship maneuvering assistance device 1 may be configured as a computer or control device installed on the ship, or may be configured by a computer different from the computer installed on the ship. The computer different from the computer installed on the ship may be, for example, a mobile terminal such as a tablet terminal or a smartphone, or may be a computer installed at a facility on land. In addition, the ship maneuvering assistance device 1 may be configured so that some of the functions constituting the ship maneuvering assistance device 1 are performed by a computer installed on the ship and other functions are performed by a computer different from the computer installed on the ship, and data is transmitted between them via a predetermined communication device.

[0017] The input device 2 constitutes an interface into which data such as ship information, obstacle information, and ship operation amount (to be described later) is input. For example, the input device 2 may be configured as a communication interface or as an input device that allows a user to input operations. The memory 3 stores the data input to the input device 2. The memory 3 also stores a hull model of the ship and a ship-maneuvering assistance program (to be described later). The memory 3 includes, for example, a main memory such as RAM or ROM, and a writable storage such as a hard disk or flash memory. The calculator 4 is constituted, for example, by a CPU. The calculator 4 executes a calculation process to calculate a dangerous thrust command value range for the ship based on the various data stored in the memory 3. To this end, the calculator 4 (or a computer including the calculator 4) executes the ship-maneuvering assistance program to fulfill functions such as an information acquisition unit 41, a dangerous thrust command value range calculation unit 42, a dangerous thrust command value range display unit 43, and an operation simulation unit 44. The display device 5 is constituted by a general-purpose display device or the like. The display device 5 is configured to display the calculation results of the calculator 4 on a display screen.

[0018] The information acquisition unit 41 acquires own ship information relating to the position, course, and speed of the target ship (hereinafter referred to as own ship Sm) obtained from position information of the target ship using a Global Navigation Satellite System (GNSS) such as GPS, and measurement information from various sensors provided on the own ship such as a compass, gyrocompass, wind direction and speed indicator, water speed indicator, etc. The information acquisition unit 41 may simply acquire own ship information from an external source, or, for example, the information acquisition unit 41 may calculate the course and speed of the own ship from the position information of the own ship per unit time, etc.

[0019] Furthermore, the information acquisition unit 41 acquires obstacle information relating to the position, course, and speed of obstacles within a predetermined range determined based on the position and / or attitude (e.g., course, etc.) of the ship Sm. The boundary of the predetermined range may be defined as a circle or polygon of a predetermined radius centered on the position of the ship Sm, or as a predetermined shape elongated in the course direction. The obstacle information includes other ship information and fixed object information. Other ship information is information relating to the position, course, and speed of other ships obtained from the Automatic Identification System (AIS). Fixed object information is information relating to the position of fixed objects such as quays and reefs obtained from nautical chart information.

[0020] The information acquisition unit 41 acquires such ship information and obstacle information and stores it in the memory 3. The dangerous thrust command value range calculation unit 42 uses this information to calculate a dangerous thrust command value range DZ (see Figure 4, described later) for the magnitude and direction of thrust that the ship Sm can output. The dangerous thrust command value range DZ is a range of command values for the magnitude and direction of thrust that the ship Sm can output, within which it is estimated that there is a possibility of the ship coming into contact with an obstacle. First, the dangerous thrust command value range calculation unit 42 calculates the ship's relative position P and relative velocity V with respect to the obstacle from the ship information and obstacle information. The relative position P and relative velocity V may be either a scalar or a vector. Here, a predetermined safety amount h = h(P) for the ship with respect to the obstacle is defined using the relative position P and relative velocity V.

[0021] For example, the safety quantity h is defined as a safety quantity function that decreases as the relative position P of the ship Sm to the obstacle approaches and decreases as the relative speed V of the ship Sm to the obstacle increases in the direction of approach. For example, if the safety quantity function is expressed as a positional relationship (scalar) on a line connecting the ship Sm and the obstacle, it is defined as follows: h=(d-δ)-T·v…(1) Here, d is the relative distance (scalar) between the ship and the obstacle, δ is the holding distance (margin), T is the time constant, and v is the relative velocity (scalar). d corresponds to the relative position P, and v corresponds to the relative velocity V. Note that this safety quantity function can also be expressed as a vector function using the vector relative position P and relative velocity V. If the safety quantity function h(P) defined above is positive, it is estimated that there is no possibility of contact with an obstacle.

[0022] The rate of change of the safety quantity h, as expressed by the safety quantity function, can be obtained by differentiating the safety quantity function with respect to time. For example, Lie differentiation can be used as a method of time differentiation. Here, the derivative of the relative velocity V indicates relative acceleration. Acceleration can be calculated by dividing the thrust F of the host ship Sm by the mass of the host ship Sm, according to the equation of motion. Therefore, the rate of change h' of the safety quantity h can be expressed as a function with the relative position P and thrust F as variables. That is, h' = h'(P, F). The magnitude and direction of the thrust F of the host ship Sm correspond to the magnitude and direction of the control variable U, which is the thrust command value given to a thrust generator such as a propeller. Since the propeller rotation speed is determined by the magnitude of the control variable U, the thrust F is determined by that rotation speed and the propeller specifications. Therefore, the rate of change h' of the safety quantity h can be expressed as a function with the relative position P and the control variable U as variables.

[0023] From the equation h(P) of the safety quantity obtained in this way and the equation h'(P,U) of its rate of change, the following inequality constraints on the manipulated variable U are defined. h'(P,U)≧-a(h(P))…(2) Here, a(h(P)) is a function with h(P) as a variable. This function a(h(P)) returns an output with the same sign as the input. Therefore, the right-hand side of equation (2), -a(h(P)), becomes positive when h(P) is a negative value. Note that in equation (2), an equation in which h(P) is multiplied by a positive constant k may be used as the inequality constraint instead of the right-hand side.

[0024] The dangerous thrust command value range calculation unit 42 calculates a range of operation amount U (thrust command value) for the magnitude and direction of the thrust F of the ship that can be output by the ship, such that the rate of change of the safety amount h is equal to or greater than a reference value determined according to the safety amount h at that time. For example, if the safety amount h is expressed by the safety amount function of the above equation (1), the dangerous thrust command value range calculation unit 42 calculates the magnitude f of the thrust of the ship in the direction of the obstacle based on the magnitude and direction of the thrust F that the ship can output, and substitutes this f for F in the inequality constraint condition shown in the above equation (2) to determine whether the above equation (2) is satisfied. In the example of the above equation (1), the current relative distance d between the ship and the obstacle is substituted for the relative position P.

[0025] The dangerous thrust command value range calculation unit 42 determines whether or not the above-mentioned inequality constraint condition is satisfied for multiple combinations of thrust magnitude and direction that can be output by the ship. For example, the magnitude of thrust that can be output is divided into a predetermined number of stages, and a predetermined reference direction (e.g., forward) as the direction of thrust that can be output is set to 0°, and the angle from that reference direction (e.g., clockwise angle) is divided into a predetermined number of stages, thereby setting multiple calculation points from among the combinations of thrust magnitude and direction that can be output by the ship. The dangerous thrust command value range calculation unit 42 performs the above-mentioned determination for each of the multiple calculation points. The dangerous thrust command value range calculation unit 42 extracts, as dangerous thrust command values, combinations of thrust magnitude and direction that do not satisfy the inequality constraint condition in the above determination.

[0026] Figure 2 is an image diagram of the process for extracting a dangerous thrust command value in this embodiment. The outer frame indicated by UZ in Figure 2 has a reference point Qo (thrust F = 0) at its center and shows the region (output possible range UZ) of the magnitude and direction of thrust (command value) F that can be output by the ship Sm. At any point within the output possible range UZ, the greater the distance between the reference point Qo and the any point, the greater the thrust F. Furthermore, the up, down, left, and right of the output possible range UZ correspond to the front, back, left, and right of the ship Sm, and the direction of any point relative to the reference point Qo indicates the direction of thrust F.

[0027] 2, the direction of the thrust force F is divided into stages every 45° around the reference point Qo with the forward direction being 0° (8 directions), and the magnitude of the thrust force F in each direction is divided into 10 stages (80 calculation points Qc) as the plurality of calculation points. Note that the setting manner of the calculation points Qc is not limited to this, and the calculation points Qc can be set in various ways.

[0028] Figure 3 is a diagram showing an example of the positional relationship between a ship and an obstacle. In this example, the obstacle, another ship Sob, approaches from the right front of the ship Sm to the left front of the ship Sm and follows a course that crosses in front of the ship Sm. The ship Sm is equipped with at least one propulsion unit TH. The propulsion unit TH is configured, for example, with an azimuth thruster or the like that can generate thrust in any direction within the horizontal direction.

[0029] In Fig. 2, the dangerous thrust command value range calculation unit 42 performs the above-mentioned determination on multiple calculation points Qc in the positional relationship between the host ship Sm and the other ships Sob as shown in Fig. 3, and the calculation points that do not satisfy the above-mentioned inequality constraint condition are indicated by an x. That is, the dangerous thrust command value range calculation unit 42 extracts the calculation points indicated by an x as dangerous thrust command values.

[0030] The dangerous thrust command value range calculation unit 42 calculates a range including the extracted dangerous thrust command value as the dangerous thrust command value range DZ. In the example of FIG. 2, the dangerous thrust command value range calculation unit 42 performs interpolation calculation between the multiple calculation points Qc based on the above determination result for each calculation point Qc, and determines a boundary line DB of the dangerous thrust command value range DZ. The boundary line DB may be a straight line as shown in FIG. 2, or a curved line. The dangerous thrust command value range calculation unit 42 sets the side including the calculation point extracted as the dangerous thrust command value as the dangerous thrust command value range DZ, using the boundary line DB as a reference. The dangerous thrust command value range display unit 43 displays the calculated dangerous thrust command value range DZ on the display screen of the display unit 5.

[0031] Note that the above-described interpolation calculation is not essential. For example, the dangerous thrust command value range DZ may be defined as a set of extracted dangerous thrust command values. Furthermore, for example, the dangerous thrust command value range DZ may be defined by line segments connecting the extracted dangerous thrust command values.

[0032] The manner in which the dangerous thrust command value range DZ is calculated is not limited to the above. That is, it is not limited to the manner in which the determination results for each predetermined calculation point Qc are referenced. For example, the output range that two-dimensionally displays the combinations of the magnitude and direction of the thrust F that can be output by the ship Sm may be divided by a boundary line between the satisfaction and non-satisfaction of the above equation (2), which is the inequality constraint condition on the manipulated variable U, and the side that does not satisfy the inequality constraint condition may be set as the dangerous thrust command value range DZ.

[0033] For example, if the safety quantity function is defined so that the rate of change of the safety quantity h' is in the form of a linear function with respect to the manipulated variable U, the region of the safe manipulated variable U defined by equation (2) can be expressed by dividing it into straight lines. Alternatively, it is possible to define the rate of change of the safety quantity function h' so that it does not take the form of a linear function with respect to the manipulated variable U. In that case, the region of the safe manipulated variable U defined by equation (2) is expressed by a mathematical equation that is not a straight line.

[0034] 4 is a diagram showing an example of a display screen in this embodiment. The display screen 50 includes an output possible range display area 51 that two-dimensionally displays a combination of the magnitude and direction of thrust that can be output by the ship Sm. The output possible range display area 51 corresponds to the output possible range UZ shown in FIG. 2. That is, at any point within the output possible range display area 51, the distance between the reference point Qo and the any point indicates the magnitude of the thrust F, and the direction of the any point relative to the reference point Qo indicates the direction of the thrust F. The dangerous thrust command value range display unit 43 two-dimensionally displays the dangerous thrust command value range DZ on the output possible range display area 51. For example, the dangerous thrust command value range DZ is highlighted in a display manner (such as by changing the color) that is different from that of the other areas of the output possible range UZ.

[0035] The dangerous thrust command value range DZ does not necessarily have to be displayed as one continuous region. For example, when the dangerous thrust command value range DZ is defined as a set of extracted dangerous thrust command values, the dangerous thrust command value range display unit 43 may display multiple calculation points Qc in the output possible range display area 51, and may display calculation points extracted as dangerous thrust command values from the multiple calculation points Qc in a different display mode from the other calculation points (not extracted as dangerous thrust command values). Furthermore, when there are multiple inequality constraint conditions related to the manipulated variable U, the ranges in which the conditions are not satisfied for each of the multiple conditional expressions may be calculated as the dangerous thrust command value range DZ, and these may be combined. In this case, not only a mode in which a determination is made for each calculation point Qc, but also a mode in which a boundary line between whether a conditional expression is satisfied and whether it is not satisfied may be applied.

[0036] Selecting a thrust command value (magnitude and direction) within the dangerous thrust command value range DZ in the output range display area 51 allows the user to navigate a dangerous thrust course C as shown in FIG. NG Therefore, the possibility of approaching and colliding with the obstacle (the other ship Sob in FIG. 3) that is the subject of the calculation increases. In other words, the thrust command value within the dangerous thrust command value range DZ includes a direction in which there is a possibility of contact with the obstacle and a magnitude in which there is a possibility of contact with the obstacle within the reference time. On the other hand, selecting a thrust command value outside the dangerous thrust command value range DZ on the display screen 50 means selecting a route C with a thrust that can avoid danger as shown in FIG. OK Moreover, it means choosing route C with thrust that can avoid danger. OK The operator can arbitrarily select a value outside the dangerous thrust command value range DZ.

[0037] Furthermore, the dangerous thrust command value range display unit 43 displays a current thrust marker M indicating the combination of the magnitude and direction of the current thrust F of the ship Sm on the output possible range display area 51. In other words, the display allows one to see at a glance whether the command value of the current thrust F is within the dangerous thrust command value range DZ or not, and even if it is outside the dangerous thrust command value range DZ, whether it is close to the dangerous thrust command value range DZ.

[0038] Furthermore, the dangerous thrust command value range display unit 43 can display changes over time in the dangerous thrust command value range DZ on the display screen 50. More specifically, when a predetermined combination (set input values) of the magnitude and direction of thrust F is input to the input device 2, the dangerous thrust command value range display unit 43 displays on the display screen 50 changes over time in the dangerous thrust command value range DZ as the reference time tb elapses when the ship Sm is navigated for a predetermined time while keeping the magnitude and direction of thrust F constant.

[0039] For example, the set input value input to the input device 2 may be the magnitude and direction of the current thrust F of the ship Sm, or the magnitude and direction of the thrust F arbitrarily input to the input device 2 by a user such as a ship operator.

[0040] The operation simulation unit 44 performs an operation simulation of the ship Sm using a predetermined hull model that models the behavior of the ship Sm based on the input setting input values.

[0041] For this purpose, a hull model that models the behavior of the ship Sm is stored in advance in the memory device 3. In addition, information such as external forces acting on the ship Sm is input from the input device 2. For example, the hull model is defined as an equation of motion for each of the decomposed forces obtained by decomposing the resultant force of wind pressure, fluid force, and thrust F of the ship Sm into a force X acting in the fore-and-aft direction (surge direction), a force Y acting in the lateral direction (sway direction), and a force moment N acting at the angle of turning (yaw angle).

[0042] Here, the wind pressure is calculated using a known calculation method such as the formula proposed by Isherwood or Fujiwara from values measured by a wind direction and speed measuring instrument installed on the ship Sm.Furthermore, the fluid force is calculated using a known calculation method such as the formula proposed by MMG or the cross-flow drag model from the ship Sm's speed over the ground, speed over the water, and measurements from a tidal current sensor.

[0043] The equation of motion that defines the hull model of the own ship Sm is expressed as follows, for example: where M is the hull mass, J Z is the ship's moment of inertia, u is the longitudinal speed, v is the lateral speed, r is the turning angular velocity, x G is the longitudinal center of gravity position as seen from the center of the hull, y G indicates the position of the center of gravity in the left and right directions as viewed from the center of the hull.

[0044]

number

[0045] When the ship Sm is assisted by a support ship such as a tugboat, a hull model that includes the force acting on the ship Sm from the tugboat as an external force may be applied.

[0046] The operation simulation unit 44 calculates the position, course, and speed of the ship Sm for each predetermined reference time tb based on the input set values as a result of the operation simulation. The reference time tb can be set according to the size and maximum ship speed of the ship Sm or the ship speed during the simulation. For example, the larger the ship Sm, the longer the reference time tb is set, and the faster the ship speed of the ship Sm, the shorter the reference time tb is set.

[0047] The dangerous thrust command value range calculation unit 42 calculates the dangerous thrust command value range DZ for each reference time tb using the calculated position, course, and speed of the ship Sm for each reference time tb. The course and speed of the obstacle at this time are fixed at the current course and speed. If the obstacle is moving (for example, if the obstacle is another ship Sob), the position of the obstacle can be found by calculating the position after the reference time tb has elapsed from the current position at the current speed. As mentioned above, ship operation commands are generally three-dimensional, consisting of the fore-and-aft direction, the lateral direction, and the turning angle. Therefore, the dangerous thrust command value range DZ can be calculated as a two-dimensional range by expressing the inequality constraints in two dimensions, for example by fixing the turning angle at the current operation command.

[0048] The dangerous thrust command value range display unit 43 displays on the display screen 50 the changes in the dangerous thrust command value range DZ at each reference time tb when the ship Sm is sailed for a predetermined time with the magnitude and direction of the thrust F of the ship Sm kept constant.

[0049] Figure 5 is a diagram showing an example of how the dangerous thrust command value range changes over time on the display screen in this embodiment. In the example of Figure 5, the display screen 50 also includes an output possible range display area 51 that displays the same information as in Figure 4. In the example of Figure 5, the combination of the magnitude and direction of the current thrust F of the ship Sm (the position of the current thrust marker M) is used as the set input value, the reference time tb is set to 30 seconds, and the dangerous thrust command value range DZ is displayed sequentially on the display screen 50 (output possible range display area 51) every 30 seconds.

[0050] Note that the switching of the elapsed time (for example, switching the display from [present] to [30 seconds later]) may be performed based on a user operation, or may be performed automatically (such as switching the display after a few seconds). Furthermore, the dangerous thrust command value range DZ at a time when the calculation of the dangerous thrust command value range DZ is not being performed may be estimated by interpolation from the dangerous thrust command value ranges DZ calculated at a plurality of timings, thereby displaying a continuous change over time in the dangerous thrust command value range DZ (as a moving image). For example, (continuous change in) the dangerous thrust command value range DZ from [present] to [30 seconds later] may be estimated from the dangerous thrust command value range DZ at [present] and the dangerous thrust command value range DZ at [30 seconds later].

[0051] Alternatively, a plurality of output possible range display areas 51 may be provided on one display screen 50, and the dangerous thrust command value range DZ at each time may be displayed in each output possible range display area 51. That is, for example, the dangerous thrust command value ranges DZ at the four timings shown in Fig. 5 may be displayed on one display screen 50. In this case, four output possible range display areas 51 are provided on one display screen 50.

[0052] Fig. 6 is a diagram showing another example of a manner in which a change in the dangerous thrust command value range over time is displayed on the display screen in this embodiment. As shown in Fig. 6, the dangerous thrust command value ranges DZ for each reference time tb may be displayed in different display modes in a single output possible range display area 51. In Fig. 6, the dangerous thrust command value range DZ0 at the present time, the dangerous thrust command value range DZ1 at 30 seconds later, the dangerous thrust command value range DZ2 at 60 seconds later, and the dangerous thrust command value range DZ3 at 90 seconds later are displayed in a single output possible range display area 51.

[0053] For example, the multiple dangerous thrust command value ranges DZ0 to DZ3 may be displayed in different colors or in different color intensities. Note that in the example of Fig. 6, if the multiple dangerous thrust command value ranges DZ0 to DZ3 overlap, the one closest to the current value is displayed with priority. Alternatively, the multiple dangerous thrust command value ranges DZ0 to DZ3 may be displayed transparently.

[0054] According to the ship maneuvering assistance device 1 having the above configuration, the range of command values estimated to result in the possibility of contact with an obstacle (such as another ship Sob) among the magnitudes and directions of thrust that the ship Sm can output based on the ship information and obstacle information is displayed on the display screen 50 as the dangerous thrust command value range DZ. More specifically, according to the rate of change of the safety quantity h determined based on the relative position P and relative velocity V of the ship Sm with respect to the obstacle (such as another ship Sob), the thrust command value of the ship Sm that may result in dangerous operation in relation to the obstacle is displayed on the display screen 50 as the dangerous thrust command value range DZ. Therefore, a user such as a ship helmsman can freely determine the operation content from among the combinations of magnitudes and directions of thrust F that the ship Sm can output, while taking into account the dangerous thrust command value range DZ displayed on the display screen 50. In other words, ship maneuvering (such as avoiding a collision) can be performed by taking into account the display content (determination result) of the ship maneuvering assistance device 1 and the ship helmsman's judgment.

[0055] Therefore, even when an avoidance target that is difficult for the information acquisition unit 41 to acquire as obstacle information, such as a whale or other marine organism, is visually recognized, the operation content can be flexibly determined. Furthermore, by quantitatively determining and determining the magnitude and direction of the thrust F rather than selecting an operation pattern, it is possible to consider as an option, for example, temporarily maneuvering the ship with the magnitude and direction of the thrust F within the dangerous thrust command value range DZ in order to avoid the avoidance target that was not recognized as an obstacle. In this way, the above configuration can provide the ship operator with suggestions for determining the operation content to avoid obstacles flexibly and quantitatively.

[0056] Furthermore, the display screen 50 can also display temporal changes in the dangerous thrust command value range DZ associated with the predicted position of the ship Sm, etc., which are obtained based on the operation simulation of the ship Sm. This allows for prediction of risks associated with the operation to be performed by the ship helmsman in advance, providing the ship helmsman with information to more appropriately determine the operation, thereby giving the ship helmsman ample time to decide on the operation.

[0057] In addition, the dangerous thrust command value range DZ is displayed two-dimensionally on the output range display area 51, which two-dimensionally displays the combination of the magnitude and direction of the thrust F that can be output by the own ship Sm, so the operator can easily understand the thrust range DZ at a glance.

[0058] In addition, since the current thrust marker M is displayed on the output range display area 51, the positional relationship between the current operation content of the own ship Sm and the dangerous thrust command value range DZ can be easily understood, and the validity of the operation content can be easily confirmed.

[0059] (Other embodiments) The present invention is not limited to the above-described embodiment, and various modifications are possible without departing from the gist of the present invention.

[0060] For example, in the above embodiment, the output range display area 51 is divided into a dangerous thrust command value range DZ and another range (so-called a safe thrust range), but a caution range CZ may be provided between the dangerous thrust command value range DZ and the safe thrust range. Fig. 7 is a diagram showing an example of a display screen in another embodiment.

[0061] In the example shown in Fig. 7, a boundary line CB is drawn between the boundary line DB of the dangerous thrust command value range DZ and the reference point Qo, at a predetermined distance from the boundary line DB, and the range between the boundary line DB and the boundary line CB is set as a caution range CZ. Selecting a thrust F (magnitude and direction) within the caution range CZ in the output possible range display area 51 allows the user to select a course C with a dangerous thrust as shown in Fig. 3. NG This means choosing a route that is closest to the target.

[0062] Therefore, the possibility of approaching and colliding with the obstacle (other ship Sob in FIG. 3) that is the subject of calculation increases slightly. In this way, by providing a step-by-step display based on the calculated dangerous thrust command value range DZ, the degree of danger (or safety) of adopting that thrust F can be visually determined. Note that the caution range CZ may include multiple ranges in which the degree of danger increases as the range approaches the dangerous thrust command value range DZ. In this case, the multiple ranges may be displayed in different display modes.

[0063] Furthermore, when the operation amount U of the ship Sm is within the dangerous thrust command value range DZ (when the current thrust marker M is located within the dangerous thrust command value range DZ), the display device 5 may output a predetermined alarm (sound, display, etc.). Similarly, when the combination of the magnitude and direction of the thrust F of the ship Sm is within the caution range CZ, the display device 5 may output a predetermined alarm. The alarm output when it is within the caution range CZ may be in a different form from the alarm output when it is within the dangerous thrust command value range DZ.

[0064] Furthermore, when the current thrust command value (operation amount U) for the ship Sm is within the dangerous thrust command value range DZ, the calculator 4 may correct the current thrust command value to a command value outside the dangerous thrust command value range DZ. Fig. 8 is a block diagram showing a schematic configuration of a ship maneuvering assistance device according to a modified example of an embodiment of the present disclosure. Components similar to those in Fig. 1 are assigned the same reference numerals, and description thereof will be omitted.

[0065] In the example of Fig. 8, the calculator 4B (or a computer including the calculator 4B) executes a ship maneuvering assistance program to perform functions such as a determination unit 45 and a command value correction unit 46 in addition to the information acquisition unit 41, dangerous thrust command value range calculation unit 42, and dangerous thrust command value range display unit 43 that are similar to those in the above embodiment. The determination unit 45 acquires information on the current thrust command value (operation amount U) and determines whether the current thrust command value (operation amount U) for the ship Sm is within the dangerous thrust command value range DZ. If the current thrust command value is within the dangerous thrust command value range DZ, the command value correction unit 46 corrects the current thrust command value to a command value outside the dangerous thrust command value range DZ.

[0066] For example, when the current thrust marker M is located within the dangerous thrust command value range DZ, the command value corrector 46 may calculate a thrust command value that is close to the position of the current thrust marker M but outside the dangerous thrust command value range DZ, and use this as the current thrust command value (command value for the actuator). A general solver capable of solving convex constraint problems may be used to calculate the thrust command value at this time. Alternatively, when the current thrust marker M is located within the dangerous thrust command value range DZ, the command value corrector 46 may use, as the current thrust command value (command value for the actuator), a thrust command value that corresponds to the position of a calculation point Qc that is outside the dangerous thrust command value range DZ, among calculation points Qc that are close to the position of the current thrust marker M.

[0067] According to this modification, when the current command value of the ship Sm falls within the dangerous thrust command value range DZ, the current thrust command value is corrected to a command value outside the dangerous thrust command value range DZ. Therefore, regardless of the operation amount U of the ship helmsman, the ship can be steered using a thrust command value that falls outside the dangerous thrust command value range DZ. Moreover, the ship helmsman can freely determine the operation amount outside the dangerous thrust command value range DZ. Therefore, the thrust command value of the ship Sm can be determined so as to avoid obstacles flexibly and quantitatively.

[0068] In this modified example, the dangerous thrust command value range DZ may also be displayed on the display screen 50, but it is not essential to display it on the display screen 50. In this modified example, the calculator 4B may also function as the operation simulation unit 44, perform an operation simulation of the own ship Sm, and display on the display screen 50 changes in the dangerous thrust command value range DZ every time the reference time tb elapses.

[0069] The display screen 50 may also be configured as an operation input screen such as a touch panel. That is, the display device 5 may function as the input device 2. In this case, for example, the magnitude and direction of the thrust F at a position touched within the output range display area 51 may be set as the input value when performing an operation simulation. Alternatively, if the display device 5 that also functions as the input device 2 is provided within the ship Sm, the magnitude and direction of the thrust F at a position touched within the output range display area 51 may be input as an operation command value for the ship Sm. That is, the display device 5 may be provided on the input device 2 for operating the thrust of the ship Sm. This makes it possible to actually operate the thrust of the ship Sm on the display screen 50 that displays the dangerous thrust command value range DZ. In this case, a current thrust marker M is displayed at the touched position.

[0070] Furthermore, when the display device 5 is provided inside the ship Sm, the display device 5 may be provided near the input device 2 used to operate the thrust of the ship Sm. For example, when the input device 2 provided on the ship Sm to operate the thrust of the ship Sm is configured as a joystick-type input device, the display screen 50 may be provided around the base of the joystick. In this case, the center position of the base of the joystick is set to the position of the reference point Qo. Alternatively, the input device 2 used to operate the thrust of the ship Sm may be a pointing device, a lever, a dial, a throttle, or the like. In this case, the display device 5 may be provided on or near the input device 2.

[0071] Furthermore, as described above, the ship maneuvering assistance device 1 in the above embodiment does not need to be installed inside the target ship. In other words, as long as information about the target ship (own ship information) and obstacle information can be acquired, the target ship can be set (selected) arbitrarily. In other words, the user of the ship maneuvering assistance device 1 does not have to be the helmsman of the target ship. For example, the user of the ship maneuvering assistance device 1 may be a land-based manager or a pilot accompanying the own ship Sm. [Explanation of symbols]

[0072] 1. Navigation support device 4,4B computing unit 5 Display 41 Information Acquisition Department 42 Dangerous thrust command value range calculation section 43 Dangerous thrust command value range display section 44 Operation Simulation Section 50 display screen 51 Output range display area DZ Dangerous thrust command value range M Current thrust marker Sm own ship (vessel) Sob Other ships (obstacles) TH propulsion machine

Claims

1. A ship-steering assistance device for a ship helmsman to determine operation details for a ship including at least one propulsion unit, a computing unit and a display unit that displays the results of the computation performed by the computing unit; The computing unit Obtaining own ship information relating to the position, course and speed of the ship, and obstacle information relating to the position, course and speed of obstacles within a predetermined range determined based on the position and / or attitude of the ship; calculating a range of command values for the magnitude and direction of thrust that can be output by the ship from the ship information and the obstacle information, which are estimated to cause contact with the obstacle, as a dangerous thrust command value range; a ship-steering assist device that displays the dangerous thrust command value range on a display screen of the display device.

2. The computing unit calculating the position, course and speed of the vessel for each predetermined reference time period for a predetermined combination of the magnitude and direction of the thrust of the vessel by simulating the operation of the vessel using a predetermined hull model that models the behavior of the vessel; calculating the dangerous thrust command value range for each reference time lapse using the calculated position, course, and speed of the ship for each reference time lapse; 2. The ship maneuvering assistance device according to claim 1, wherein the display screen displays a change in the dangerous thrust command value range for each reference time when the ship is navigated for a predetermined time while maintaining a constant magnitude and direction of the thrust of the ship.

3. the display screen includes an output range display unit that two-dimensionally displays a combination of magnitudes and directions of thrust command values that can be output by the vessel, 3. The ship maneuvering assist device according to claim 1, wherein the computing unit displays the dangerous thrust command value range two-dimensionally on the output possible range display unit.

4. 4. The ship maneuvering assist device according to claim 3, wherein the computing unit displays a current thrust marker on the output range display unit, the current thrust marker indicating a combination of a magnitude and a direction of the current thrust command value for the ship.

5. 5. The ship maneuvering assistance device according to claim 1, wherein the calculator uses a safety quantity function that defines a safety quantity that decreases as the relative position of the ship to the obstacle approaches a predetermined reference value and that decreases as the relative speed of the ship to the obstacle increases in the approach direction, and calculates a range of the command value such that a rate of change of the safety quantity is equal to or greater than a reference value that is defined in accordance with the safety quantity.

6. 6. The ship maneuvering assistance device according to claim 5, wherein the computing unit determines the dangerous thrust command value range using an inequality constraint condition related to the thrust of the ship obtained from the safety quantity function and a function having the relative position and the thrust of the ship as variables obtained by differentiating the safety quantity function with respect to time.

7. 7. The ship maneuvering assist device according to claim 1, wherein the display is provided on or near an input device for operating the thrust of the ship inside the ship.

8. The computing unit determining whether a current command value for the thrust magnitude and direction of the vessel is within the critical thrust command value range; 8. A ship maneuvering assist device according to claim 1, wherein, when the current command value is within the dangerous thrust command value range, the current command value is corrected to a command value outside the dangerous thrust command value range.

9. A ship-steering assistance program for allowing a ship helmsman to determine operation details for a ship including at least one propulsion unit, comprising: Computer, an information acquisition unit that acquires own ship information relating to the position, course, and speed of the ship, and obstacle information relating to the position, course, and speed of obstacles within a predetermined range determined based on the position and / or attitude of the ship; a dangerous thrust command value range calculation unit that calculates, based on the ship information and the obstacle information, a range of command values for the magnitude and direction of thrust that can be output by the ship, which is estimated to cause contact with the obstacle, as a dangerous thrust command value range; and a ship-maneuvering assistance program that causes the computer to function as a dangerous thrust command value range display unit that displays the dangerous thrust command value range on a display screen of the computer.

10. The computer a motion simulation unit that calculates the position, course, and speed of the ship for each predetermined reference time period for a predetermined combination of the magnitude and direction of the thrust of the ship by simulating the operation of the ship using a predetermined hull model that models the behavior of the ship; the dangerous thrust command value range calculation unit calculates the dangerous thrust command value range for each reference time period using the calculated position, course, and speed of the ship for each reference time period; 10. The ship maneuvering assistance program according to claim 9, wherein the dangerous thrust command value range display unit displays on the display screen a change in the dangerous thrust command value range for each reference time period when the ship is navigated for a predetermined time period while maintaining a constant magnitude and direction of the thrust of the ship.

11. The computer: a determination unit that determines whether a current command value for the magnitude and direction of thrust of the vessel is within the dangerous thrust command value range; and 11. The ship-maneuvering assistance program according to claim 9, wherein the program causes the program to function as a command value correcting unit that, when the current command value is included in the dangerous thrust command value range, corrects the current command value to a command value outside the dangerous thrust command value range.

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