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EP-4560264-B1 - NAVIGATION PLANNING SYSTEM AND NAVIGATION PLANNING METHOD

EP4560264B1EP 4560264 B1EP4560264 B1EP 4560264B1EP-4560264-B1

Inventors

  • UOSHITA, Seiichi

Dates

Publication Date
20260513
Application Date
20231124

Claims (12)

  1. A navigation planning system (100), comprising: a navigation planning route acquiring module (11) configured to acquire a planned route that a movable body (200) moving on water should follow from a departure point to a destination; a movable body information acquiring module (12) configured to acquire movable body information including a position, a moving direction, and a speed of the movable body (200); an obstacle information acquiring module (13) configured to acquire obstacle information including each of a position, a moving direction, and a speed of a plurality of obstacles (204, 206) located in a surrounding area of the movable body (200); a collision risk calculator (14) configured to calculate a collision risk indicating a risk level of collision between the movable body and an obstacle of the plurality of obstacles based on the movable body information and the obstacle information; a congestion risk calculator (15) configured to calculate congestion risk indicating a degree of approaching the plurality of obstacles simultaneously based on each of the collision risk between the movable body and each of the plurality of obstacles; the system characterised by : a risk evaluator (16) configured to determine the necessity of evasion by comparing the congestion risk with a threshold value; a maximum collision risk selector (18) configured to select a maximum collision risk obstacle corresponding to a maximum collision risk among the plurality of obstacles, wherein the risk evaluator (16) further includes a maximum collision risk evaluator (20) configured to determine the necessity of evasion by comparing the maximum collision risk with a maximum collision risk threshold; an evasion route setting module (17) configured to set an evasion route different from the planned route for a part of or entire unnavigated route of the planned route when the risk evaluator (16) determines the necessity of the evasion route, and wherein the evasion route setting module (17) includes: a potential evasion route generator (22) configured to generate one or a plurality of potential evasion routes different from the planned route between an evasion starting point and a return point on the unnavigated route; and an evasion route selector (21) configured to select the evasion route from the plurality of potential evasion routes based on the maximum collision risk and the congestion risk for each of the potential evasion routes.
  2. The navigation planning system (100) according to claim 1, wherein: the congestion risk calculator (15) is configured to calculate the congestion risk of the planned route based on a logical sum of the plurality of collision risks.
  3. The navigation planning system (100) according to claim 2, wherein: the congestion risk calculator (15) is further configured to calculate the congestion risk based on the collision risks including the maximum collision risk from the plurality of collision risks.
  4. The navigation planning system (100) according to any of claim 1 to 3, wherein: the congestion risk calculator (15) is further configured to calculate the congestion risk for each of the potential evasion route based on the plurality of collision risks.
  5. The navigation planning system (100) according to claim 4, wherein: the collision risk calculator (14) is further configured to calculate the maximum collision risk for each of the one or more potential evasion routes, and the congestion risk calculator (15) is further configured to calculate the congestion risk for each of the one or more potential evasion routes.
  6. The navigation planning system (100) according to claim 5, wherein: the collision risk calculator (14) is further configured to calculate the maximum collision risk for each of the potential evasion route when the movable body navigates the potential evasion route, and the evasion route selector (21) is further configured to: select an evasion route for which the maximum collision risk is equal to or less than the threshold.
  7. The navigation planning system (100) according to claim 6, wherein: the evasion route selector (21) is further configured to: determine to allow to switch the planned route to the evasion route when the maximum collision risk corresponding to the selected evasion route is less than the maximum collision risk for the planned route.
  8. The navigation planning system (100) according to claim 7, wherein: the congestion risk calculator (15) is further configured to calculate the congestion risk of the evasion route when the movable body navigates the selected evasion route, and the evasion route selector (21) is further configured to determine to allow to switch the planned route to the evasion route when the congestion risk corresponding to the selected evasion route is less than the congestion risk for the planned route.
  9. The navigation planning system (100) according to claim 8, wherein: the evasion route selector (21) is further configured to select the evasion route in which the distance traveled by the movable body is minimized among the plurality of potential evasion routes in which the maximum collision risk and the congestion risk value are both equal to or less than a predetermined threshold.
  10. A navigation route planning method, comprising: acquiring a planned route that a movable body (200) moving on water should follow from a departure point to a destination; acquiring movable body information including a position, a moving direction, and a speed of a movable body on water; acquiring obstacle information including each of a position, a moving direction, and a speed of a plurality of obstacles (204, 206) located in a surrounding area of the movable body; calculating a collision risk indicating a risk level of collision between the movable body and each obstacle of the plurality of obstacles based on the movable body information and the obstacle information; calculating congestion risk indicating a degree of approaching the plurality of obstacles simultaneously based on the collision risk between the movable body and each of the plurality of obstacles; the method characterised by : determining necessity of evasion by comparing the congestion risk with a threshold value; selecting a maximum collision risk obstacle corresponding to a maximum collision risk among the plurality of obstacles, determining necessity of evasion by comparing the maximum collision risk with a maximum collision risk threshold; setting an evasion route different from the navigation planning route for a part of or entire unnavigated route of the planned route when the necessity of the evasion route is determined, wherein setting the evasion route includes: generating one or a plurality of potential evasion routes different from the planned route between an evasion starting point and a return point on the unnavigated route; and selecting the evasion route from the plurality of potential evasion routes based on the maximum collision risk and the congestion risk for each of the potential evasion routes.
  11. The navigation route planning method according to claim 10, further comprising: calculating the maximum collision risk for each of the one or more potential evasion routes and the congestion risk the congestion risk for each of the one or more potential evasion routes; and determining the evasion route based on the calculated maximum collision risk and congestion risk.
  12. The navigation planning method according to claim 11, further comprising: selecting the evasion route in which the distance traveled by the movable body is minimized among the plurality of potential evasion routes in which the maximum collision risk and the congestion risk value are both equal to or less than a predetermined threshold.

Description

TECHNICAL FIELD The present invention relates primarily to a vessel navigation system and method for safely navigating a vessel, and more specifically, to a navigation planning system and a route planning method for safely navigating a vessel by avoiding collision with a plurality of obstacles around an own vessel. BACKGROUND In general, a vessel or other movable body establishes a planned route for a voyage from a departure point to a destination before beginning the navigation. Currently, movable bodies such as vessels may have navigation systems and devices for generating planned routes and monitoring planned routes in order to safely move movable bodies. In these conventional navigation planning systems, movable bodies such as own vessels acquire movable body information and obstacle information using a plurality of sensor units in order to detect, identify, and track their own positions and the positions of nearby obstacles and other vessels on the planned route in order to avoid collisions with other obstacles such as other vessels. Patent document 1: US2020/0310434 A1. WO 2021/ 149 448 A1 teaches to provide a vessel monitoring device that allows a user to intuitively and easily recognize information on the possibility of a collision. Such a vessel maneuvering support device comprises a risk map generation unit and a display data generation unit. When the position, which is on a planned course estimated for a second vessel and determined to evaluate the risk of a first vessel colliding with the second vessel, is called a risk evaluation position assuming veering of the first vessel among a plurality of vessels, the risk map generation unit estimates the possibility of collision between the first vessel and the second vessel at a position other than the risk evaluation position, and generates a risk map showing the distribution of the estimated possibility of a collision. The display data generation unit generates display data for displaying the risk map. SUMMARY Problems to be solved by the Invention While navigating the planned route, the planned route may have to be changed due to artificial factors such as the appearance of nearby obstacles or other vessels that may cross the planned route. In addition, the planned route may have to be changed due to natural factors such as sudden changes in ocean conditions, tides, or other disturbance factors. For this reason, vessel operators must safely navigate movable bodies such as own vessels along the planned route, avoiding collisions with surrounding obstacles and other vessels, and may need assistance navigating ocean conditions and tides. The problem to be solved by the present invention is to provide systems, devices, and methods that support vessel operators to safely navigate movable bodies by responding to the above requirements and avoiding collisions with multiple obstacles and other vessels. Means and Effects of solving the problem The above problem is solved by the subject-matter of the independent claims. In the navigation planning system, the congestion risk calculator may calculate a congestion risk of a planned route and a congestion risk of an evasion route based on the logical sum of a plurality of collision risks. Here, the collision risk calculator may calculate a maximum collision risk for each of one or a plurality of potential evasion routes, and a congestion risk calculator calculates a congestion risk for each of one or a plurality of potential evasion routes. The collision risk calculator may calculate a maximum collision risk when a movable body navigates the potential evasion route for each of the potential evasion routes, and the evasion route selector may select a potential evasion route whose maximum collision risk is less than or equal to a predetermined threshold as the evasion route, and determine whether the maximum collision risk corresponding to the selected evasion route is less than the maximum collision risk for the planned route, and determine that navigation of the evasion route is necessary when the maximum collision risk is small. Here, the congestion risk calculator may calculate the evasion route congestion risk in the case where the movable body navigates the selected evasion route, and the evasion route selector may further determine that the navigation of the selected evasion route is necessary when the evasion route congestion risk is smaller than the congestion risk for the planned route. The evasion route selector may further determine the necessity of the evasion by taking into account the distance of each potential evasion route navigated by the movable body for each potential evasion route. The evasion route selector may select the potential evasion route for which the distance navigated by the movable body is the minimum among potential evasion routes whose maximum collision risk and congestion risk are both equal to or less than a predetermined threshold. In the navigation planning system of the pres