JPH0120643Y2 - - Google Patents

Description

[Detailed explanation of the invention] (a) Industrial application field The present invention relates to an automatic navigation system for ships. The present invention relates to an automatic navigation system for a ship that calculates a course based on a sea route and adjusts a rudder angle via an autopilot.

(b) Prior Art For example, in vessels that navigate using navigation methods such as great-area navigation, it has been the practice to plan a route based on a designated departure point, destination, navigation method, and a memorized nautical chart. The course is calculated from the set route selected from among the routes, the target course is taken, and the rudder angle is adjusted via the autopilot.In addition, when the ship deviates from the set route due to various disturbances such as waves, wind, and currents. If the current position of the ship as determined by the position determiner is
There is an automatic navigation system for ships that instructs an autopilot to change course in order to maintain the planned route when a preset deviation amount limit value is exceeded from the set route.

Devices of this type called total navigation systems or integrated navigation systems have been put into practical use, but these devices are designed with automatic navigation functions based on the following ideas. ing.

``Plan the route to the destination at an early stage taking into account the weather and sea conditions, and decide one of the routes as the set route. Then, be sure to maneuver the ship along the set route until the final destination.'' The idea is that if a ship deviates from the set route from its departure point to its final destination, it will be returned to the set route one by one.

This will be explained below using the system diagram of the automatic navigation system for a ship shown in FIG. This device includes a route setting means 1, a route keeping and course setting means 2,
It has a ship maneuvering means 3, a ship position determining means 4, and a deviation comparing means 5. First, the departure point, destination, and navigation method are input to the route planning section 7 in the navigation condition input section 6 of the route setting means 1. At this time, not only several navigation directions to the final destination are input as necessary, but also intermediate destinations and navigation directions to each intermediate destination, etc., as the case may be. On the other hand, information such as a nautical chart to the departure point, intermediate destination, or final destination (hereinafter referred to as destination) is also input to the route planning section 7 as necessary from the nautical chart storage section 8 in which nautical charts are stored in advance. . In this route planning section 7, several routes are planned on the screen based on the above information, and one route is determined from among the planned routes.
The two routes are stored in the route setting section 9 as set routes. The route set in this way is output from the route setting means 1 to the route keeping and course setting means 2, which calculates the course to the destination based on the set route. , the course is input to the autopilot 10 of the ship maneuvering means 3. Since the autopilot 10 commands the rudder angle to the rudder 11 based on the course, the ship 12
will sail on that course. Note that the direction of the ship's bow is always detected by the compass 13, so if the ship's bow is heading on a different course, the autopilot 1 will
0 outputs the modified rudder angle command to the rudder 11.
On the other hand, since the ship may deviate from the set route due to various disturbances such as waves, wind, and currents, the ship position detecting section 14 of the ship position determining means 4 detects
The current position of the ship is measured by a Navy Navigation Satellite System (NNSS) or the like, or the position is estimated from a log based on the compass 13. Based on the position information of several ships obtained in this way, the ship position determining section 15 determines the current position. This position and the route setting section 9
is inputted to the deviation amount calculation unit 16 of the deviation amount comparison means 5 and compared with the set route, and the deviation amount from the set route is calculated. A comparison unit 17 compares whether this deviation exceeds a deviation limit value set in advance in the deviation limit value setting unit 18, and if it exceeds the deviation amount, the course keeping and course setting means 2 determines whether the ship is The current course is calculated so as to return to the set course, and this is input to the autopilot 10 of the vessel maneuvering means 3 in the same way as described above, and then the rudder angle is commanded to the rudder 11 based on the corrected course. , Vessel 1 to return to the set route.
2 will sail on that course.

As a result, with respect to the set route, which is the shortest route, ships will follow the route shown by the exaggerated imaginary line in Figure 2 each time, and take routes that detour from the set route at various points to reach the destination. sail to. Therefore, ships move back and forth in the vicinity of the set shortest route, following a route that is not the shortest route, resulting in longer voyage times and increased fuel consumption.
The disadvantage is that uneconomical operation is forced.

(c) Purpose of the invention This invention was made to solve the above-mentioned problems, and the route from the departure point to the destination is not fixed, and if deviations from the specified route occur due to the influence of various disturbances, the route will be fixed. , without returning to the predetermined route from the current position, automatically calculates the remaining route from that position to the destination as a new route for the time being, replaces the calculated route with the predetermined route, and follows the shortest route to the destination. As a result, the ship's voyage time is shortened and fuel consumption is reduced.
The purpose is to provide an automatic navigation system for ships that enables economical navigation.

(d) Structure of the invention The automatic navigation system for a ship according to the invention is applied to an automatic navigation system for a ship that adjusts the rudder angle via an autopilot 10 so as to take a target course. The feature is that when the position of the vessel 12 exceeds a preset deviation amount limit value from the predetermined route, a new shortest route from that position to the destination is planned. A shortest route planning means 21 comprising a storage unit 8 and a shortest route calculation unit 26, and if the planned shortest route passes through a dangerous area, the plan of the shortest route is corrected so as to avoid the dangerous area. In order to do so, the dangerous area avoidance route planning means 22 includes a dangerous area designation unit 27, a dangerous area confirmation unit 28, and a dangerous area avoidance route calculation unit 29, and the dangerous area avoidance route is replaced with the predetermined route as a temporary route. If the position of the ship 12 exceeds a preset deviation amount limit value from the predetermined course, the current course determining means 23 determines a course correction amount from the history of the deviation rate, and corrects the target course of the predetermined course. In order to
and a target course determining means 24 for determining a target course based on the above-mentioned current route and the above-mentioned course correction amount.

In addition, as described in the conventional example, when a ship deviates from the set route, returning to the set route in order to maintain the set route does not result in the shortest route to the destination, and the amount of deviation If the deviation amount exceeds the limit value, it is better to set a new shortest route to the destination based on the ship's position at that time, which will result in the shortest voyage to the destination. This is based on the knowledge that

(e) Examples Hereinafter, the present invention will be explained in detail based on examples thereof.

FIG. 3 is an overall system diagram of an automatic navigation system for a ship which is an embodiment of the present invention, in which the shortest route planning means 21,
The main components are a dangerous area avoidance route planning means 22, a temporary route determining means 23, a course correcting means 30, and a target course determining means 24.

To be more specific, the shortest route planning means 21 plans a route from a departure point to a destination based on navigation conditions and nautical conditions such as a nautical chart, and determines one of the routes to determine an initial route. or, if necessary, plan the shortest route as described below. Its configuration includes a navigation condition input section 6, a nautical chart storage section 8, and a shortest route calculation section 26.

The dangerous area avoidance route planning means 22 corrects the initial route or the shortest route planned by the shortest route planning means 21 as necessary so that it does not pass through the dangerous area. That is, if the planned shortest route passes through a dangerous area, the plan for the shortest route is revised to avoid the dangerous area. Its composition is
It has a dangerous area designation section 27, a dangerous area confirmation section 28, and a dangerous area avoidance route calculation section 29.

The temporary route determining means 23 sets the dangerous area avoidance route planned by the dangerous area avoidance route planning means 22 as the temporary route, and selects the initial route or the previous temporary route replaced thereafter (hereinafter collectively referred to as the predetermined route). It replaces it.

The course correction means 30 determines a course correction amount from the history of the deviation rate when the position of the ship exceeds a preset deviation amount limit value from a predetermined route;
This is for correcting the target course of the predetermined route. This is composed of a deviation rate calculation section 31 and a course correction amount calculation section 32.

The target course determining means 24 calculates the course to the destination based on the predetermined route of the current route determining means 23 and the above-mentioned course correction amount, and inputs the course to the autopilot 10 of the vessel maneuvering means 3.

Note that the ship maneuvering means 3, the ship position determining means 4, and the deviation comparing means 5 are the same as those described in the conventional example, but the deviation comparing means 5 is such that the ship moves along a predetermined course due to various disturbances such as waves, wind, and currents. If the current position of the ship determined by the ship position determining means 4 exceeds the deviation amount limit value from the predetermined route, the system instructs the shortest route planning means 21 to perform calculations. , the deviation and the history of the amount of deviation are calculated by the deviation rate calculation unit 31 of the course correction means 30.
This is what you input.

According to such an embodiment, the ship can be automatically navigated so as to always take the shortest route in the following manner.

First, the departure point, destination, and navigation are input in the navigation condition input section 6 of the shortest route setting means 21. At this time, not only several navigation directions to the final destination are input as necessary, but also navigation directions to an intermediate destination or each intermediate destination, etc., as the case may be. On the other hand, information such as a nautical chart from the pre-stored nautical chart storage unit 8 to the intermediate destination or the final destination, which is another one of the voyage conditions, is input to the shortest route calculation unit 26. Then, several routes are planned on the visual screen, and one route determined from among the planned routes is output to the dangerous area avoidance route planning means 22, and is planned according to the procedure described below. The dangerous area avoidance route is input as an initial route to the route determining means 23 for the time being and is stored there. Then, the information is directly input to the target course determining means 24, the course to the destination is calculated based on the initial route, and the target course determining means 24 determines what course to take.
4. This target course is input to the autopilot 10 of the ship maneuvering means 3, and the autopilot 10 instructs the rudder 11 to set a rudder angle based on the course. As a result, the ship 12 navigates along that course. In addition, the direction of the bow is always set to compass 1.
3, the autopilot 10 outputs a corrected rudder angle command to the rudder 11 based on the signal from the compass 13 if the bow is heading to a different course.

On the other hand, since the ship may deviate from the set route due to various disturbances such as waves, wind, and currents, the ship position detecting section 14 of the ship position determining means 4 measures the ship's position at that time using a deck or the like. , the location can be estimated from a log based on the compass 13. Based on the position information of several ships obtained in this way, the ship position determining section 15 determines the current position. This position and the initial route stored in the current route determining means 23 or the predetermined route which is the current route replaced thereafter are inputted to the shift amount calculation section 16 of the shift amount comparing means 5 and compared, and the predetermined route is determined. The amount of deviation from is calculated. A comparator 17 compares whether this amount of deviation exceeds a deviation amount limit value preset in the deviation amount limit setting section 18, and if it exceeds it, a calculation command is issued to the shortest route calculation section 26 of the shortest route planning means 21. This shortest route calculation section 26
calculates a new shortest route from the current position to the final destination based on information from the navigation condition input section 6 and the nautical chart storage section 8. This calculation is performed in almost the same way as when planning the initial route, but it may be based only on the navigation conditions adopted as the initial route, or it may be based on partially modified navigation conditions. Then, when the shortest route is calculated, this shortest route is determined by the dangerous area avoidance route planning means 2.
2, and the dangerous area confirmation unit 28 determines whether or not the vehicle is passing through a dangerous area based on the information from the dangerous area designation unit 27. If the danger area has not been passed, the danger area avoidance route calculation unit 29
For the time being, the shortest route passing through is route determination means 2.
3, is stored replacing the previous predetermined route, and is output to the target course determining means 24. The subsequent control is the same as described above.
This situation is shown in Figure 4, and the initial route A
From there, the predetermined route changes sequentially to the current route B, C, and D as necessary, and the ship navigates as shown by the broken line.

In addition, if the shortest route mentioned above passes through the danger area, the danger area avoidance route calculation section 29 calculates the fifth route.
The shortest route that avoids the dangerous area is calculated according to the procedure shown in the figure, and it is used as the route determining means 2 for the time being.
3 is input. That is, if the shortest route B passes through a dangerous area surrounded by a circle or an ellipse on the nautical chart, two provisional shortest routes a and b that touch the circle or ellipse are calculated. Then, the shorter of these routes, the shortest route b in the illustration, is selected as the shortest route that avoids the dangerous area. It goes without saying that such calculations can be performed for all remaining routes from the current ship position to the final destination, or can also be performed for intermediate destinations.

By the way, the deviation comparing means 5 calculates the deviation from the predetermined route at that time based on the information from the ship position determining means 4, and calculates the second and third immediate routes as described above. However, it is conceivable that the ship may still have to deviate from the current course and navigate on the fourth or fifth current course, so the course correction means 30
The course correction is performed as follows. In other words, there are influences such as weather and tidal currents before the ship deviates beyond the deviation amount limit value, but since these conditions are considered to remain the same for a certain period of time, the deviation amount calculation unit 16 calculates the previous deviation confirmed position. The amount of deviation from to the current deviation amount confirmation position is detected one by one and input to the deviation rate calculation unit 31. When the deviation rate calculation unit 31 receives a signal to calculate the deviation rate from the comparison unit 17, it calculates the deviation rate K based on the deviation amount in the manner shown in FIG. This deviation rate K is the route deviation amount n, which is how much the currently confirmed position deviates from the current route B calculated at the previous confirmed position, from the perpendicular line from the current confirmed position to the previous current route B. It is calculated using the ratio of the distance m to the previously confirmed position. Therefore, the deviation rate K
= given by n/m. To subdivide and explain this deviation rate K, as shown in FIG.
Based on the information from 6, the deviation rate is calculated for each time when the deviation amount changes. Now, as shown in the figure, from the time Ta at the previously confirmed position to the next time Tb
The deviation rate from time Tb to the next time Tc is Kc, Kd and Ke are calculated in the same way,
The total deviation rate K is Kb+Kc+Kd+Ke. If you include a special situation on a nautical chart, such as a place with strong currents, the effect will be noticeable and will appear, for example, as Kd shown in the diagram. Therefore, for the current route C calculated at the current confirmed position, the course correction amount calculation unit 32 calculates the correction amount for the upper course by calculating the following course correction coefficient. This correction coefficient α is calculated as α=[{λb・Kb/(Tb−Ta)}+{λc・Kc/(Tc−Tb
)} +{λd・Kd/(Td−Tc)}+{λe・Ke/(Te−Td)
}]/β, which is multiplied by the course of the current route C determined by the current route determining means 23 in the target course determining means 24 to correct the target course in FIG. 6 in the direction of arrow 33. Note that λb, λc, λd, and λe are weighting coefficients, and their magnitudes are determined each time. Also, β
is a coefficient selected from preset numerical values such as 2 and 3. In this case, if there is a noticeable deviation rate that is constant for a certain period of time near the current confirmed position, it is better to focus on this as it can be better reflected in the course of the next route C for the time being as a course correction. , the weighting coefficient λ of that term in the correction coefficient α is made different from that of the other terms. For example, if it is known in advance that there will be no strong tidal currents on route C for the time being, the weighting coefficient λc of the tidal current term in the correction coefficient If you know something, make it bigger,
The correction coefficient α obtained as a result is adopted. Also,
If there is no significant change in the deviation rate for each time shown in FIG. 7, it is sufficient to use α=(Kb+Kc+Kd+Ke)/(Te−Ta) as the correction coefficient α. In this way, the course of the current route C reflects the factors that were influenced when the ship was previously navigating the current route B, so even if the course is in the direction of arrow 33, the ship will be guided to the current route C or to the current route C. It is possible to follow an approximate route, and it is possible to avoid the problem of having to frequently determine a new route for the time being. This course correction is not performed frequently, but is performed only when the course deviation exceeds the deviation limit value, as described above.
Corrections to the target course based on the next immediate route are also possible.
Limits are placed on the amount of correction to prevent large steering changes. By correcting the target course in this way, the predetermined route becomes longer than the initially planned route, and the need to frequently calculate the stranding avoidance route is eliminated, and the shortest route can be followed overall to the final destination. The method of determining the limit value for the amount of deviation of the route is as follows:
If it is made smaller, it will often be necessary to recalculate the route or correct the target course, increasing the number of steering turns and causing a loss of propulsion energy.
The design is made to ensure that no losses occur and that the vessel is not too large to pose a risk of running aground.

Although the above description has been made regarding ships that perform great-circle navigation, the present invention is applicable to ships that navigate using other navigation methods based on great-circle navigation, such as range-line navigation based on gradual latitude navigation, or integrated great-circle navigation. Needless to say, it can also be applied. It can also be applied to cases where radar images are used without using nautical charts.

(f) Effects of the invention As explained in detail above, the invention provides an automatic navigation system for ships, which has a shortest route planning means, a dangerous area avoidance route planning means, a temporary route determining means, a course correction means, and a target course determining means. Therefore, even if a ship deviates from its course due to a disturbance, it can navigate the shortest route to its destination, and moreover, it can automatically navigate safely by avoiding the risk of running aground. Therefore,
It is possible to navigate the shortest route without unnecessary steering, and it is possible to achieve greater energy savings compared to conventional ship maneuvering of this type. In addition, route changes and safety checks are automatically performed based on stored information such as nautical charts, which has the effect of further improving labor savings in vessel operation.

[Brief explanation of the drawing]

Fig. 1 is an overall system diagram of a conventional automatic navigation system for a ship, Fig. 2 is a route chart showing the conventional actual route for a set route, and Fig. 3 is an overall system diagram of an automatic navigation system for a ship according to the present invention. Figure 4 is a route chart showing the current route and the ship's route relative to the initial route, Figure 5 is a route chart for calculating routes to avoid dangerous areas, Figure 6 is a route chart showing deviation rates and course corrections, and Figure 7 is a history history. FIG. 2 is a graph showing the relationship between the deviation rate and time and explaining the procedure for calculating the deviation rate in consideration of the deviation rate. FIG. 6... Navigation condition input section, 8... Nautical chart storage section, 1
0... Autopilot, 11... Rudder, 12...
Vessel, 21... Shortest route planning means, 22... Dangerous area avoidance route planning means, 23... Temporary route determining means, 24... Target course determining means, 26... Shortest route calculation unit, 27... Dangerous area designation Section, 28... Dangerous area confirmation section, 29... Dangerous area avoidance route calculation section, 30... Course correction means, 31... Deviation rate calculation section, 32... Course correction amount calculation section.

Claims (1)

[Scope of Claim for Utility Model Registration] In an automatic navigation system for a ship that adjusts the rudder angle via an autopilot so that the ship follows a target course, if the position of the ship exceeds a preset deviation limit value from a predetermined course, In order to plan a new shortest route from a position to a destination, a shortest route planning means is provided that includes a navigation condition input section, a nautical chart storage section, and a shortest route calculation section, and the planned shortest route passes through a dangerous area. If so, in order to modify the plan of the shortest route to avoid the danger area, a danger area avoidance route planning means comprising a danger area designation part, a danger area confirmation part, and a danger area avoidance route calculation part; Temporary route determination means that replaces the dangerous area avoidance route with the predetermined route as the current route, and when the position of the vessel exceeds a preset deviation amount limit value from the predetermined route, a course correction amount is determined based on the history of the deviation rate. and a course correction means comprising a deviation rate calculation section and a course correction amount calculation section in order to correct the target course of the predetermined route; An automatic navigation device for a ship, comprising: a course determining means;