JPH0578476B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Application Field] This invention is installed on a ship to avoid running aground or colliding with fixed targets or other ships in narrow waters, etc., and to faithfully navigate along a safe scheduled route. The present invention relates to a planned route following device that controls a steering gear and a main engine. [Prior Art] Generally, when a ship navigates a narrow sea area such as a narrow water area, there are many dangers such as running aground or colliding with fixed targets. It is essential to maneuver the ship so that it sails faithfully. By the way, as mentioned above, when navigating a safe route with a fixed target such as a reef or a fixed buoy, since the target target is fixed, it is only necessary to reach the final destination point at the target time. There is no need to consider the passing time of each point on the scheduled route. [Problem to be solved by the invention] However, in reality, in addition to fixed targets, navigation must also include avoiding collisions with other ships, and for this purpose, other ships' speed, direction, course, etc. must be considered when navigating. It is necessary to determine the passing time of each point on the scheduled route based on the ship's navigation information, and to maneuver the ship so as to pass each point on the scheduled route at the calculated scheduled passage time. The ship is operated by selecting the rudder angle, ship speed, etc. based on intuition, but determining the rudder angle, ship speed, etc. based on the navigation information of other ships, which changes from moment to moment, requires great experience and intuition. , there are problems in that there are many deviations from the planned route and there is a lack of certainty in terms of safety. Therefore, the technical problem of the present invention is to enable a ship to faithfully and automatically navigate along a safe planned route while avoiding grounding and collisions with fixed targets and other ships. [Means for Solving the Problems] This invention has been made with the above-mentioned points in mind, and it calculates the shortest scheduled route from a departure point to a target point and the route along that route based on navigation information of other ships. a scheduled route deriving means for deriving the scheduled passage time of each point; a position detecting means for detecting the current position of the ship based on signals from a gyroscope, a log, etc. and outputting a detection signal; Calculate the deviation between the position on the route and the current position according to the detection signal, and determine the optimum steering angle and optimum main engine rotation such that an evaluation function obtained by time-integrating the square of the deviation is minimized and the deviation is below a predetermined value. arithmetic means for deriving a number;
This is a scheduled route following device characterized by comprising a steering gear control means and a main engine control means for controlling the steering gear and the main engine to the optimum steering angle and the optimum main engine rotational speed. [Operation] Therefore, according to the present invention, the speed of another ship,
Based on navigation information such as direction and course, and position information of fixed targets such as reefs and fixed buoys, the planned route derivation means determines the shortest scheduled route from the departure point to the target point and the scheduled passage time of each point on the scheduled route. is derived, the current position of the own ship is detected by the position detection means based on signals from the gyrocombus, logs, etc., and the optimum rudder is determined so that the deviation between the position on the planned route at the current time and the current position is less than a predetermined value. The angle and the optimum main engine rotational speed are respectively derived by a simple calculation of the calculation means which calculates the minimum of the evaluation function obtained by time-integrating the square of the deviation, and the steering gear and the main engine are controlled by the steering gear control means and the main engine control means. is controlled to the calculated optimum steering angle and optimum main engine rotation speed. At this time, the ship passes each point on the scheduled route with the minimum deviation at the scheduled passage time when it can pass through each point on the scheduled route without colliding with other ships, and the shortest and safest route from the departure point to the destination point is achieved. This means that the ship will be able to navigate the route faithfully and automatically. [Embodiment] Next, the present invention will be described in detail with reference to drawings showing one embodiment thereof. In Figure 1, which shows the configuration of the device, 1 indicates the distance from the starting point to the target point based on navigation information such as the speed, direction, and course of other ships from radar, etc., and the position information of fixed targets such as reefs and fixed buoys. Scheduled route derivation means for deriving the shortest scheduled route and the scheduled passing time of each point on the route; 2 is a gyro compass for detecting the bearing of the own ship; 3 is a log for detecting the speed of the own ship; 4
5 is the U.S. Navy Navigation Satellite System (NNSS) that detects the ship's position, and 5 is the position detection means that detects the current position of the ship based on signals from the Gialcoropass 2, Log 3, and NNSS 4 and outputs a detection signal. , 6 is a calculation means consisting of a computer, which calculates the deviation between the position on the planned route determined by the derivation means 1 at the current time and the current position determined by the detection signal, and calculates the optimum rudder so that the deviation becomes less than a predetermined value. The angle and optimal main engine rotation speed are derived respectively. 7 superimposes and displays the radar image and the planned route determined by the deriving means 1 on the radar image, and also displays own ship information such as own ship's position and ship speed, navigation information of other ships, derivation results by the calculation means 6, etc. 8 and 9 are steering gear control means and main engine control means, respectively, which control the steering gear 10 and the main engine 11 to the optimum steering angle and optimum main engine rotation speed derived by the calculation means 6. Control. Next, the deriving means 1 derives a planned route R from the starting point O to the target point F, as shown, for example, by the solid line in FIG.
When the scheduled passage time for each point above is derived, the rudder angle and main engine rotation speed are such that the deviation from the actual route R' taken by the own ship is minimized, as shown by the dashed-dotted line in the figure. We will explain the procedure for finding . Now, when considering the movement of a ship in the X-Y plane, the speed in the X-axis direction is u, the speed in the Y-axis direction is V, the turning angle is r, and the X and Y coordinates representing the position of the ship are Assuming x, y, rudder angle as δ, and main engine rotational speed as n, the equation of motion of the ship is generally as follows:

[C], where a ₁ ,…, a ₅ , b ₁ ,…, b ₆ , c ₁ ,…
c ₆ is a constant, u〓, v〓, r〓, x〓, y〓 are u, v, respectively
The first differential of r, x, and y with respect to time t is shown. Then, it is sufficient to find the rudder angle δ and the main engine rotational speed n for each point on the planned course R so that the ship's motion trajectory given by the above formula matches the planned course R in Fig. 2 described above. , For this purpose, an evaluation function J expressed by the following equation is introduced, and δ and n are determined such that the J becomes zero. J=∫ ^tf _tp {(x ^* −x) ² + (y ^* − y) ² }dt... However, x ^* and y ^* indicate the X and Y coordinates of each point on the planned route R, and to, tf is the time at the starting point and the destination point, respectively, and the initial values, that is, the X and Y coordinates of the starting point O are xo and yo. However, although the above-mentioned evaluation function J represents the integral value obtained by time-integrating the square of the amount of deviation between the planned route R and the actual route R', the rudder angle and main engine rotation speed that can be taken by a ship actually sailing are continuous. Since the evaluation function J in the above formula cannot be zero, the steering angle and main engine rotation speed that minimize J are the ship maneuvering data to be determined. . Therefore, we define the Hamiltonian H as H=(x ^* −x) ² +(y ^* −y) ² +P _u u〓 +P _v v〓+P _r r〓+P _x x〓+P _y y〓..., and use the above formula. Applying the variational method to

It is obtained from the shared equation expressed as [Table], and the above,
When the formula is given, it can be seen that if the following formula is satisfied, the evaluation function J is minimized by the steepest gradient method. ∂H／∂〓(〓(t), 〓(t), 〓(t), t)=0... However, 〓(t)=u(t) v(t) r(t) x(t) y (t), 〓(t)=δ(t) n(t), 〓(t)=P _u (t) P _v (t) P _r (t) P _x (t) P _y (t) . Then, a control law 〓(t)=δ(t) n(t) that satisfies the above equation is determined by the following algorithm. (a) Using the deriving means 1, derive and set the planned route R to the starting point or the target point. At this time, the planned route R is a function of time, 〓(t)=[x ^* (t), y ^* (t)]
It shall be derived as follows. (However, t∈
Let it be [to, tf]. ) (b) Next, the calculation means 6 initializes an approximate value for the tentative control law 〓(t)=δ(t) n(t) near the starting point and solves the equation of motion of the above formula, ( c) The calculation means 6 solves the above equation based on 〓(t)=u(t) v(t) r(t) x(t) y(t) obtained by solving the above equation, and 〓( Find t)=P _u (t) P _v (t) P _r (t)P _x (t) P _y (t). (d) Based on |u(t), |x(t), and 〓(t) obtained in the steps of (b) and (c) above, the calculation means 6 calculates ‖
Calculate ∂H/∂〓(t)‖, and if ‖∂H/∂〓(t)‖ is a predetermined value (
For example, determine whether it is smaller than 10 ^-3 ). Here, ‖∂H/∂〓(t)‖=∫ ^tf _tp {(∂H/∂δ) ² + (
∂H/∂n) ² }dt, and ∂H/∂δ=[2a ₄ sinδcosδ+(b ₆ +c ₆
) (cos ² δ−sin ² δ)]u ² ∂H/∂n=[a ₅ +{(b ₄ +c ₄ )v+(b ₅
+c ₅ )r}u ⁻¹ ]n. (e) If ‖∂H/∂〓(t)‖ is smaller than the predetermined value, it is assumed that the above formula is approximately satisfied, and the calculation is terminated, and the control law set in (b) above 〓(t) = δ(t) n(t) Let the values of δ(t) and n(t) be the optimal steering angle and the optimal main engine rotation speed at the current time, respectively. (f) On the other hand, when ‖∂H/∂〓(t)‖ is larger than the predetermined value, the control law set in (b) above, the values of δ(t) and n(t) of 〓(t) as δ(i) and n(i) respectively

〔Effect of the invention〕

As described above, according to the scheduled route following device of the present invention, the scheduled route is determined by means for deriving a scheduled route based on navigation information such as speed, direction, course, etc. of other ships, and position information of fixed targets such as reefs and fixed buoys. The shortest planned route from the target point to the target point and the estimated passing time of each point on the planned route are derived, and the current position of the own ship is detected by position detection means based on signals from the gyro compass, logs, etc. Simple calculation means for calculating the minimum of an evaluation function obtained by time-integrating the square of the deviation to determine the optimum rudder angle and optimum main engine rotation speed such that the deviation between the position on the scheduled route at the time and the current position is equal to or less than a predetermined value. The steering gear and main engine were controlled by the steering gear control means and the main engine control means to the calculated optimum rudder angle and optimum main engine rotation speed, respectively, resulting in a collision with a fixed target or another ship or a grounding. The ship will pass each point on the shortest scheduled route from the departure point to the destination point at the scheduled passage time with the minimum deviation, allowing the ship to follow the scheduled route faithfully and It becomes possible to navigate automatically, and it is possible to improve safety in ship navigation.

[Brief explanation of the drawing]

The drawings show one embodiment of the planned route following device of the present invention, with FIG. 1 being a block diagram and FIG. 2 being an operation explanatory diagram. 1... Planned route derivation means, 2... Gyroscope compass, 3... Log, 5... Position detection means, 6
...Calculating means, 8...Steering gear control means, 9...
Main engine control means, 10... Steering gear, 11... Main engine.

Claims (1)

[Scope of Claims] 1. Scheduled route derivation means for deriving the shortest scheduled route from a departure point to a target point and the scheduled passing time of each point on the scheduled route based on navigation information of other ships, etc.; and a gyroscope. , a position detection means for detecting the current position of the own ship based on signals from a log etc. and outputting a detection signal; a calculation means for deriving an optimal steering angle and an optimum main engine rotation speed such that an evaluation function obtained by time-integrating the square of the deviation is minimized and the deviation is equal to or less than a predetermined value; and a steering gear control means and a main engine control means for controlling the main engine.