KR102594519B1 - Estimation and visualization method of rudder angle rage with collision risk using the time-space domain of turning for collision prevention in the auto-remote of maritime autonomous surface ships - Google Patents

Abstract

Disclosed in the present invention is a method for estimating and visualizing a collision risk rudder angle range using a turning time-space domain for preventing a collision in remote control of an autonomous ship, which can prevent incorrect rudder angle use of a remote controller to prevent a collision and secure safe navigation. The method for estimating and visualizing a collision risk rudder angle range using a turning time-space domain for preventing a collision in remote control of an autonomous ship according to the present invention relates to: a method and procedure for estimating and visualizing a collision risk for a control rudder angle of a remote controller; a method for estimating a start time of collision avoidance using remote control data; a method for constructing and implementing a turning time-space domain using a ship turning circle; a method for determining a range of a collision rudder angle using the control rudder angle of the remote controller; a method for warning a collision risk for the control rudder angle of the remote controller; a method for visualizing the range of the collision rudder angle and the collision risk on a screen; and a method for estimating and visualizing the range of the collision risk ruder angle using the turning time-space domain for preventing a collision in remote control of an autonomous ship, which includes a diagram of a visualization screen for monitoring the range of the collision rudder angle and the collision risk.

Description

Estimation and visualization method of rudder angle rage with collision risk using the time-space domain of turning for collision prevention in the auto -remote of maritime autonomous surface ships}

The present invention relates to collision avoidance using the rudder angle of the ship in remote control of autonomous ships. More specifically, remote control using a remote control system operated at a remote location when operating an autonomous ship. In the process, when delays such as vessel response delay, data transmission/reception delay, remote controller reaction delay, etc., and collision situations occur, the delay time is estimated using the data acquired during the remote control process, and the control point for collision avoidance considering the delay is determined. , using the turning time-space domain that sets this control point as the coordinate origin, the collision position with another vessel is obtained by the control rudder angle commanded by the remote controller, and the collision is expected to change according to environmental changes based on the collision position. After estimating the range of the dangerous rudder angle in turning time and space, both the control rudder angle that the remote controller wants to use and the range of the collision risk rudder angle are visualized on the screen and warn of the risk of collision, thus contributing to collision prevention by supporting the remote controller's collision avoidance. It is for.

Currently, research and development on autonomous ships is being actively conducted at sea, similar to autonomous vehicles on land. Automation systems can speed up the flow of logistics by at least 10%, and human error accounts for 82% of all maritime accidents. It has been found that accidents can be resolved and costs can be reduced by more than 60% through reduced labor costs. These autonomous ships are referred to as MASS (Maritime Autonomous Surface Ship) by the International Maritime Organization (IMO), and are usually divided into four levels, with level 1 being designed to support crew decision-making on existing ships. Level 2 is the level at which remote control is possible with a crew member on board the ship, and Level 3 is the level at which remote control is possible when there is no crew member on board or only a minimum number of people are on board and the engine is automated. Lastly, Level 4 is a completely unmanned level where there are no people on board the ship, and the domestic and international development goals are between Level 2 and Level 3, where remote control is possible by adding a remote control device to an existing manned ship (a ship controlled by humans). The technology required between levels 2 and 3 is to safely control autonomous ships remotely, and for this purpose, marine accidents due to control delays that occur during the remote control of autonomous ships must be prevented.

Meanwhile, design is currently underway at home and abroad for autonomous ships that are between level 2 and level 3, and there are no ships built as autonomous ships yet, which are currently considered international maritime transportation according to international regulations. This is because it is determined that all ships engaged in must be controlled by humans (seafarers).

Accordingly, research on land remote control systems is being actively conducted as a way to ensure the operational safety and effectiveness of autonomous ships. This is to prepare for cases where autonomous operation is not possible due to this reason. In addition, land control is necessary for all existing ships, because there are cases where the navigator cannot directly control the ship in various situations such as collision between ships, fire, departure from route, and drunk driving.

Meanwhile, the remote control of an autonomous ship consists of three elements (ship, control system, and remote controller), and as it is executed through cyclical and repetitive control between the three elements, any delay phenomenon occurs in the organic operation between them. It is known that this delay phenomenon can occur due to various environments (ship reaction delay, communication network failure and delay, control system signal processing delay, decision-making delay by remote controller, etc.).

Delays in remote control cause two major problems: failure of situational awareness and failure of remote control. Situational awareness failure occurs because the current situation around the autonomous ship is delayed until it is transmitted to the remote controller, and the remote controller cannot recognize the current situation. Remote control failure occurs when the remote controller's control command does not reach the ship. This occurs because the ship cannot be controlled at the desired time by the remote controller due to delays until the desired time. As a result, accidents such as collisions and strandings may occur, and the sailing distance may increase due to deviating from the planned route.

Therefore, there is an urgent need to prevent marine accidents due to control delays during the operation of autonomous ships and to prepare alternatives that can estimate the planned route. In particular, it is necessary to scientifically and quantitatively estimate the risk of collision due to the remote controller's control actions. There is a need to secure the operational safety and economic feasibility of autonomous ships through research on how to make decisions and visualize them.

Meanwhile, the control rudder angle refers to the rudder angle for controlling an autonomous ship. Collision avoidance is mainly performed using the control rudder angle. The method of evaluating the risk of collision based on the control rudder angle of the remote controller is: 1) Long-term rudder angle There are 2) evaluation methods based on years of ship handling experience, 2) evaluation methods using a ship handling simulator, and 3) numerical evaluation methods using a ship handling model.

However, the above-mentioned evaluation method based on long-term ship operation experience is not suitable for remote control of autonomous ships pursuing unmanned ships,

The method of evaluating using the ship handling simulator has the problem of requiring an expensive ship handling simulator and taking a lot of time to evaluate the risk of collision.

The method of numerical evaluation using the ship handling model had the problem of requiring complex numerical analysis and taking time for evaluation.

Registered Patent Publication No. 10-1941896 (2019.01.18.) Registered Patent Publication No. 10-2042058 (2019.11.01.) Registered Patent Publication No. 10-2000155 (2019.07.09.) Public Patent Publication No. 10-2018-0045440 (2018.05.04.) Registered Patent No. 10-1937439 (2019.01.04.) Registered Patent No. 10-1937443 (2019.01.04.)

The present invention was created to solve the problems of the prior art as described above. The purpose of the present invention is to establish a ship in advance using the ship's specifications (length, width, speed, etc.) and turning power when the ship to be controlled is determined. The purpose of this study is to provide a method for estimating and visualizing the collision risk range using the turning space-time domain to prevent collisions in the remote control of autonomous ships that can quickly evaluate the collision risk for the control angle by using the turning space-time domain.

In addition, the present invention includes a method and procedure for estimating and visualizing the risk of collision with respect to the control angle of the remote controller, a method for estimating the start time of collision avoidance using remote control data, and a method for estimating the start time of collision avoidance using the ship's right of turn. A construction and implementation method, a method of determining the range of the collision angle using the remote controller's control angle, a method of warning of the risk of collision based on the remote controller's control angle, and a method of visualizing the collision angle range and collision risk on the screen. The purpose is to provide a method for estimating and visualizing the collision risk angle range using the turning time-space domain for collision prevention in remote control of autonomous ships, which consists of a method and a diagram of a visualization screen for monitoring the collision angle range and collision risk.

The method for estimating and visualizing the collision risk angle range using the turning space-time domain to prevent collisions in remote control of autonomous ships according to a preferred embodiment of the present invention for realizing the above purpose is to control all remote control that occurs during the control process. A control angle collision performed through a remote control procedure process of obtaining and storing data, and a range estimation and visualization process of the collision avoidance angle that calls the obtained remote control data to estimate the collision avoidance time and determines whether collision avoidance is necessary. Danger warning stage;

A remote control data acquisition step due to delays occurring in the data transmission and reception process, response delays of the remote controller in the control process, and response delays of the ship in the ship control process;

A collision avoidance start time estimation step for estimating the time at which the control rudder angle is effectively applied to ship control after the delayed time and collision avoidance starts;

An estimation step of the collision angle range for estimating the range of the collision angle that reflects the collision angle at which collision avoidance may fail and the navigation situation and control delay;

A process of constructing a turning time-space domain, a process of acquiring control point data in the current control state, a process of estimating the collision avoidance start time, a process of calculating the ship position at the start time of collision avoidance, a process of determining the need for collision avoidance, and turning the ship. Implementation step of collision angle range estimation consisting of a collision time calculation process, a collision position calculation process, a collision radius calculation process, and a collision risk determination process for the remote controller's control angle;

It is characterized in that it consists of a visualization step of the collision angle range consisting of the control angle, the estimated collision angle range, and the remote controller's control angle.

As a preferred feature of the present invention, in the remote control procedure, the remote controller is a remote control consisting of a remote control device, a transmitting and receiving device (STx, CRx, CTx, SRx), and a communication network (LTE, LTE-M, V-SAT). The system is used to control the ship (MASS) continuously and repeatedly, and all remote control data generated during this control process is stored in the database.

As another preferred feature of the present invention, the process of estimating and visualizing the range of the collision angle of impact includes estimating the start time of collision avoidance by calling remote control data from a database storing remote control data generated during the control process; and estimating the start time of collision avoidance. At the start time, the relative distance between the main ship (MASS) and other ships (other ships or objects subject to collision avoidance) is calculated to determine whether collision avoidance is necessary; if it is determined that collision avoidance is necessary, the main ship is determined by the control rudder angle. When making this turn, the location at which a collision may occur with another vessel is determined using the turning space-time domain; the range of the collision angle and the collision risk level of the control angle are evaluated and determined, and then visualized to warn of the risk of collision. .

As another preferred feature of the present invention, the remote control data acquisition step is performed using (method 1) below.

(method 1)

1) At time T1, ship control data (S-data) including ship control results and navigation status is transmitted to the transmitter (STx) and received at time T2 by the receiver (CRx).

2) The S-data received at time T2 is input to the remote control device to visualize the navigation situation at time T1, and the remote controller performs remote control while viewing the navigation situation at T1 to generate control data (C-data). After input to the transmitter (CTx) at time T2.

3) At time T3, C-data is transmitted through the transmitter (CTx), and at time T4, the ship receives C-data.

4) The ship is controlled using C-data input at time T4, and ship control data (S-data) including the control results and navigation status is input to the transmitter (STx) at time T1.

5) Similar to 1) above, S-data is transmitted to the transmitter (STx) at time T1 and received by the receiver (CRx) at time T2.

As another preferred feature of the present invention, the remote control data is stored in the DB in the form of three types of data {S-data, C-data, T-data} that are generated from time to time while continuously repeating the above five processes. become;,

The T-data includes T1, ship data transmission time; T2, vessel data reception time; T3, control data transmission time; T4 indicates time data consisting of control data reception time. The times included in the time data are times measured using GPS during the transmission and reception of S-data and C-data.

The S-data includes OS-MMSI, ship identification number; OS-time, main line time; OS-position, ship position; OS-heading, final heading; OS-speed, own ship speed; OS-rudder-angle, main line angle; OS-Radar, own ship radar image data; OS-ECDIS, main line ECDIS video information; OS-CCTV, main line CCTV video data; TS-MMSI, batting line identification number; TS-time, batting time; TS-position, batting line position; TS-heading, batting line direction; Includes one or more of TS-speed and batting line speed,

The C-data is C-time, control command generation time; C-speed, control speed; C-heading, controlled heading; It includes one or more of C-rudder-angle and control rudder angle.

As another preferred feature of the present invention, in the collision avoidance start time estimation step, the collision avoidance start time was measured in the past using GPS based on Operator (n) in the n control state,

T2(n-1): Time when the remote controller receives ship data (S-data) in n-1 state;,

T3(n): Time when the remote controller transmits control data (C-data) in n state;,

T4(n): Time when control data (C-data) is received from the ship in n state;,

T1(n): Time when ship data (S-data) is transmitted from the ship in n state;,

T2(n): Time when the remote controller receives ship data (S-data) in n state;,

It is estimated using five types of times (T2(n-1), T3(n), T4(n), T1(n), T2(n)).

As another preferred feature of the present invention, in the estimation step of the collision angle range, the collision angle range is implemented using the ship's turning circle (trajectory of the position that appears when the ship turns in response to the control rudder angle) established in advance. It is estimated by applying a turning space-time domain (space-time showing the turning circle for the combination of rudder angle and time in x-y plane coordinates), and the method of constructing the turning space-time domain is as follows (method 2). It is in the use of .

(method 2)

The x-axis and y-axis represent the x- and y-axis distances of the turning circle in meters, respectively, and the time shown above the x-axis and to the left of the y-axis represents the turning time (t).

The ship (0,0) represents the x-y coordinate origin (0,0), and this origin represents the ship's position when receiving the control rudder angle at T4(n+1).

The turning time and space indicates the position of the turning circle that may appear at a time after T4(n+1).

The ship's course is indicated by fixing the y-axis direction to the heading zero (0) degrees, regardless of the actual course.

Based on the main ship (0,0), the turning circle (TC) according to the increase in time is displayed as a curve with 8 dotted lines for the combination of x-y positions, and the turning circle's time-distance line (Time-Distance) is a combination of time and distance. Line, TDL) is displayed as six solid lines.

The number shown in the outermost semicircle represents the rudder angle (deg.). The rudder angle used on the starboard side is from 0 degrees to 35 degrees, and the rudder angle used on the port side is only a portion of the range from 0 degrees to 10 degrees. indicates.

As another preferred feature of the present invention, in the process of constructing the turning time-space domain, the turning time-space domain (TC-domain) is established in advance using the turning circle (TC) of the ship before remote control is performed, but the TC The conditions of Equation (1) below are given to the ship's ship control model (Ship-model) and obtained in the x-y plane coordinate system, and the TC obtained when the conditions of Equation (2) below are given to Equation (1) is used. It is about building it.

Formula (1) TC(x,y,v,d) = [Ship-model | v,d]

Here, v represents the allowable speed of the ship, v = v-min,… v-max (v-min is the minimum speed, v-max is the maximum speed), and d represents the allowable rudder angle of the ship, d = 1,2,… d-max (d-max is the maximum allowable steering angle, generally around 30 degrees).

Formula (2) TC-domain(x,y,v,d,t) = [TC(x,y,v,d) | t]

Here, t represents the turning time of the ship, t = 0,… TC-time (TC-time is the time required for one turn).

As another preferred feature of the present invention, in the process of acquiring control point data in the current control state, the control point data is obtained by using time data (T-data) among the three types of data stored in the database at any time during the remote control process. In the n control state, the time data (T2-data(n,m)) based on the time (T2(n)) at which the remote controller received the ship data is obtained by configuring it in the form of an n×m matrix as follows. It's in the thing.

T2-data(n,m) ∈ {T2(n-1), T3(n), T4(n), T1(n), T2(n)}

Here, n is the control state identification number, where n = 1, 2,… N (N is the final control state), and m is the data number, where m=1,2,... M (M is the total number of data, M=5), and each time is measured using GPS time for time synchronization between the ship and the remote controller.

As another preferred feature of the present invention, in the estimation process of the collision avoidance start time, the collision avoidance start time T1 (n+1) is calculated from T2 (n-1) occurring in the n-1 control state and the n control state to T2 ( It is estimated using the following equations (3) to (8) using the delay time (DT) between n).

Formula (3) T1(n+1) = T1(n) + DT

Here, DT is calculated using equation (4) below.

Formula (4) DT = DT-T12 + DT-T23 + DT-T34 + DT-T41

Here, the four terms on the right represent the delay time (DT) calculated using equations (5) to (8) below.

Formula (5) DT-T12 = T2(n) - T1(n)

Formula (6) DT-T23 = T3(n) - T2(n-1)

Formula (7) DT-T34 = T4(n) - T3(n)

Formula (8) DT-T41 = T1(n) - T4(n)

As another preferred feature of the present invention, the process of calculating the ship position at the collision avoidance start time includes the own ship position OS-T1 (n+1) and the other ship position TS-T1 ( n+1) is calculated using equations (9) to (12) below.

Formula (9) OS-T1(n+1) = OS-T1(n)) + OS-del(x,y)

Formula (10) TS-T1(n+1) = TS-T1(n)) + TS-del(x,y)

Here, OS-T1(n) and TS-T1(n) represent the positions obtained by converting the home ship position and the other ship position measured using GPS at time T1(n) into an x-y plane coordinate system with meter units, respectively, and OS -del(x,y) and TS-del(x,y) indicate the position to which the main ship or other ships moved during the delay time (DT), and their x-axis and y-axis values are expressed in the following equation (11) ) and equation (12).

Formula (11 x = v×sin(course)×DT)

Formula (12 y = v×cos(course)×DT

Here, v and course represent the speed and heading of the main line (or other line), respectively.

As another desirable feature of the present invention, the process of determining the need for collision avoidance is that the need for collision avoidance is determined when the relative distance (DT) between the two ships at T1 (n+1) is small compared to the reference relative distance (RD-ref). However, the determination of collision avoidance is made by using the algorithm (1) below to determine that collision avoidance is necessary if Col = 1, and that collision avoidance is not necessary if Col = 0.

Algorithm (1) if (RD ≤ RD-ref) then, Col = 1 else, Col = 0

Here, RD-ref is a value determined through experiment and statistics, and is generally set at 3.25 times the ship length, and RD is calculated using the formula (13) below.

Formula (13) RD = sqrt[ (OS-x - TS-x)^2 + (OS-y - TS-y)^2 ]

Here, sqrt represents the square root, and OS-x, TS-x, OS-y, and TS-y are the x-axis value of OS, the x-axis value of TS, the y-axis value of OS, and TS. Indicates the y-axis values of .

As another preferred feature of the present invention, the process of calculating the collision time due to the main ship turning is that, when the main ship turns using the control rudder angle of the remote controller at T1 (n+1), the time of collision with the other ship uses the turning time-space domain. The collision time is derived by calculating the TC-domain(x,y,v,d,t) and TS(x ,y,t) are set as the turning time (t) that coincides with each other. Collision time (Col-time) is calculated using the conditional formula (14) below.

Formula (14) Col-time = [t|TC-domain(x,y,v,d,t)-TS(x,y,t)=0], (0≤t< TC-time)

Here, TS(x,y,t) represents the position the other ship moved during the turning time (t), and the x-axis and y-axis values are calculated using the following equations (15) and (16), respectively. Calculate.

Formula (15) x = v×sin(course)×t

Formula (16) y = v×cos(course)×t

As another preferred feature of the present invention, in the collision position calculation process, the collision position (PSN-Col) is determined as a position corresponding to the collision time (Col-time) in the turning time-space domain, using the following conditional equation (17) It is calculated using .

Formula (17) PSN-Col(x,y) = [(x,y) | TC-domain(x,y,v,d,t)(t=Col-time)]

As another preferred feature of the present invention, in the process of calculating the range of the collision angle, the range of the collision angle is determined by the radius (r) and theta (theta = 0, 1.2,... 2×3.14) at the collision location (PSN-Col). It is obtained using a collision circle (CC) with an arc angle. First, calculate x(theta) and y(theta) of CC(x,y,theta) using Equation (18) and Equation (19) below, respectively, and calculate the range of collision angle (Col-RA-range) is determined using all steering angles (d) included in CC, and these steering angles are calculated using the conditional formula (20) below.

Formula (18) x(theta) = [r×sin(theta)] + [x | Col-psn(x,y)]

Formula (19) y(theta) = [r×cos(theta)] + [y | Col-psn(x,y)]

Here, the radius r is determined through experiment and statistics, and is generally set as the radius of a circle that can be secured from 3.25 times the length of the ship to 1.0 times the width of the ship. In addition, the radius r varies depending on delay time, navigation environment, ship specifications, etc.

Formula (20) Col-RA-range(theta) = [d(theta) | TC-domain(x,y,v,d,t) ≤ CC(x,y,theta)]

And the upper limit (RA-Upper) and lower limit (RA-Lower) of the collision angle range are determined by the maximum and minimum values, respectively, of the Col-RA-range (theta).

As another preferred feature of the present invention, in the process of determining the collision risk with respect to the control angle of the remote controller, the collision risk with respect to the control angle (C-rudder-angle) of the remote controller is determined using the following algorithm (2). It's about deciding.

Algorithm (2) if (RA-Lower ≤ C-rudder-angle ≤ RA-Upper) then, RW = 1,else RW = 0

Here, RW indicates whether there is a collision risk warning (Rudder Warning) of the control rudder angle. If RW = 1, it is dangerous because the control rudder angle (C-rudder-angle) is within the range of the collision angle (RA-Lower, RA-Upper). and RW=0 indicates safety.

As another preferred feature of the present invention, in the visualization step of the collision angle range,

A display area that visualizes the remote controller's control angle and estimated collision angle range, a display area that visualizes only the remote controller's control angle, and the lower and upper limits of the collision angle (Lower) and starboard (S, starboard). Or, it is configured to include a visualization window consisting of one or more of the port (P, port) angles.

The method for estimating and visualizing the collision risk range using the turning space-time domain in the remote control of an autonomous ship according to the present invention prevents collisions by preventing the remote controller from using an incorrect rudder angle due to control delay in the remote control of an autonomous ship. By doing so, safe navigation of autonomous ships can be secured, source technology can be secured using turning time and space to evaluate the range of rudder angles that should be prohibited from being used to prevent collisions at the delayed ship's location, and The advantage of securing commercialization technology for the remote control system of autonomous navigation ships (MASS) that can estimate and visualize the range of collision risk is expected.

In addition, the advantage of high freedom of application of the technology is expected as it is possible to estimate and visualize the range of collision risk by converting ships currently in operation into autonomous ships or applying it to ships defined as autonomous ships in the future.

In addition, it is expected to have a useful effect in preventing serious damage caused by maritime accidents (collision, stranding, contact, etc.) of autonomous ships and the resulting environmental pollution and economic losses.

In addition, the method of estimating and visualizing the range of collision risk angle in the remote control of autonomous ships of the present invention uses the data itself obtained during the remote control process to eliminate unexpected risks that may occur in autonomous ships without adding additional equipment. It is expected to have a useful effect that can significantly reduce reliability and ensure reliability.

The features and advantages of the present invention will become more apparent from the following detailed description based on the accompanying drawings. Prior to this, terms or words used in this specification and claims should not be interpreted in their usual, dictionary meaning, and the inventor may appropriately define the concept of the term in order to explain his or her invention in the best way. It must be interpreted with meaning and concept consistent with the technical idea of the present invention based on the principle that it is.

1 is a schematic diagram illustrating a remote controller's control angle collision risk warning method in remote control of an autonomous ship according to the present invention;
Figure 2 is a schematic diagram illustrating the collision avoidance start time estimation method according to the present invention;
Figure 3 is a configuration diagram for explaining the configuration of the orbital space-time domain according to the present invention;
Figure 4 is a diagram illustrating a method for estimating the range of collision angle in the turning space-time domain according to the present invention;
Figure 5 is a diagram showing the configuration of a collision angle range visualization window according to the present invention;
Figure 6 is a schematic diagram showing an example of visualization of the impact angle range according to the present invention.

Hereinafter, the configuration and operation of an embodiment of the present invention will be described in detail with reference to the attached drawings. However, it is not intended to limit the present invention to a specific disclosed form, and should be understood to include all changes, equivalents, and substitutes included in the spirit and technical scope of the present invention.

In this application, terms such as “include” or “have” are intended to designate the presence of features, steps, operations, components, parts, or combinations thereof described in the specification, but not one or more other features, steps, or operations. , it should be understood that it does not exclude in advance the possibility of the existence or addition of components, parts, or combinations thereof. That is, throughout the specification, when a part "includes" a certain component, this means that it does not exclude other components but may further include other components, unless specifically stated to the contrary.

Additionally, unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as generally understood by those skilled in the art to which the present invention pertains. Terms defined in commonly used dictionaries should be interpreted as having a meaning consistent with the meaning in the context of the related technology, and unless clearly defined in the present application, should not be interpreted in an ideal or excessively formal sense. No.

Here, repeated descriptions, known functions that may unnecessarily obscure the gist of the present invention, and detailed descriptions of configurations are omitted in order to not obscure the gist of the present invention. Embodiments of the present invention are provided to more completely explain the present invention to those skilled in the art. Accordingly, the shapes and sizes of elements in the drawings may be exaggerated for clearer explanation.

First, Figures 1 to 6 are diagrams to explain a method for estimating and visualizing the collision risk angle range using the turning space-time domain to prevent collisions in remote control of autonomous ships according to the present invention.

Figure 1 is a schematic diagram illustrating a remote controller's control angle collision risk warning method in remote control of an autonomous ship according to the present invention.

The drawing shows a warning method of collision risk for the control angle commanded by the remote controller to avoid collision during the remote control process of an autonomous ship, including the remote control procedure shown in (A) and the range estimation of the collision angle shown in (B). The composition of the visualization procedure is shown.

Figure 2 is a schematic diagram for explaining the collision avoidance start time estimation method according to the present invention.

The drawing shows three types of control states that can occur over time in the remote control procedure (A) shown in Figure 1.

Figure 3 is a configuration diagram for explaining the configuration of the turning space-time domain according to the present invention. In the figure, the x-axis and y-axis represent the x-axis and y-axis distance of the turning circle in meters, respectively, and x- The time shown above the axis and to the left of the y-axis represents the turning time (t), and OS(0,0) represents the x-y coordinate origin (0,0), which is the control angle at T4(n+1). The vessel's position at the time of reception is shown.

Figure 4 is a diagram illustrating a method of estimating the range of collision angle in the turning space-time domain according to the present invention. The other ship (TS) is oriented 270 degrees with respect to the main ship (OS) (i.e., from starboard to port based on the coordinate origin). ) A configuration assuming a sailing situation is shown.

Figure 5 is a diagram illustrating the configuration of a visualization window for the collision angle range according to the present invention. In the drawing, the upper semicircle (RUDDER ANGLE RANGE (degree)) visualizes the control angle of the remote controller and the estimated collision angle range. This is the part where the long square box below (RUDDER ANGLE RANGE (Order)(degree)) shows the part that only visualizes the control angle of the remote controller.

Figure 6 is a schematic diagram showing an example of visualization of the collision angle range according to the present invention. In the drawing, the control angle of the remote controller is 25.0 degrees starboard, and 25.0 degrees starboard corresponds to the collision angle range between 19.6 degrees starboard and 31.5 degrees starboard, Therefore, the rudder warning is displayed in red to warn that a collision may occur if the remote controller applies the current control rudder angle to collision avoidance. On the contrary, if the control rudder angle does not fall within the collision angle range, a rudder warning is displayed in blue to indicate that it is safe.

The present invention is intended to implement a method for estimating and visualizing the collision risk range using the turning time-space domain to prevent collisions in remote control of autonomous ships. Remote control of autonomous ships involves three remote control elements (ship, control system, It is composed of a remote controller) and various delays occur as it is executed by circular and repetitive control between these three elements. In addition to fundamental delays that inevitably occur due to technical limitations or natural phenomena, these delays include delays in control response due to the remote controller's lack of control technology, delays in ship control response due to typhoons and bad weather, and large amounts of data. Communication delays due to transmission and reception appear collectively.

Excessive delays beyond the standard in remote control can act as a major cause of situational awareness failure and remote control failure, causing various maritime accidents. In particular, when a delay occurs, it is difficult for the remote controller to know what rudder angle should be applied to the ship at the time of the delay to avoid collision, and furthermore, it is difficult to determine whether the rudder angle to be applied for collision avoidance is suitable for collision avoidance or will actually cause a collision. do.

In other words, the main technical feature of the present invention is to estimate the start time of collision avoidance in remote control of an autonomous ship, estimate the range of collision angle at which a collision can occur from the estimated collision avoidance start time, and visualize it to the remote controller. This is to prevent collisions by notifying the use of collision risk due to delay.

Below, the range estimation and visualization method of the collision risk angle will be explained in the following order. First, 1.1 explains the collision risk warning method of the control angle, 1.2 explains the remote control data acquisition method, 1.3 explains the collision avoidance start time estimation method, and then 1.4 explains the estimation method of the collision angle range. Then, 2. We explain the implementation means of estimating the impact angle range, and finally, 3. We explain the visualization method of the impact angle range.

1.1. Control angle collision risk warning method

The collision risk warning method for the remote controller's control angle is explained using FIG. 1.

Figure 1 shows a warning method of collision risk for the control angle commanded by the remote controller to avoid collision during the remote control process of an autonomous ship. The remote control procedure shown in (A) and the range estimation of the collision angle shown in (B) are shown. and visualization procedures.

Hereinafter, the collision risk warning procedure of the control angle is explained as follows.

First, in (A) the remote control procedure, the remote controller (Operator) uses a remote control device (Auto-Remote Controller), a transceiver device (STx, CRx, CTx, SRx), and a communication network (LTE, LTE-M, V-SAT). The ship (MASS) is continuously and repeatedly controlled using a remote control system consisting of (e.g., etc.), and all remote control data generated during the control process is stored in the database (D/B).

Next, in the (B) collision avoidance range estimation and visualization procedure, the remote control data stored in D/B is called to estimate the collision avoidance start time, and the main ship (meaning MASS) is connected at the estimated collision avoidance start time. Determine whether collision avoidance is necessary by calculating the relative distance between other ships (meaning other ships or objects subject to collision avoidance). If it is determined that collision avoidance is necessary, the location where the ship may collide with another ship when turning according to the control rudder angle is determined using the turning time-space domain, and the range of the collision angle and the collision risk level of the control rudder angle are evaluated and determined. Visualizes and warns of collision risk.

Through the above process, the remote controller can prevent collisions by recognizing the risk of collision at the control angle. Here, when avoiding a collision by complying with the International Collision Prevention Rules at Sea (COLREGs), it is specified that this is done by either the speed or the rudder angle of the ship, or both the speed and the rudder angle. In the present invention, collision is avoided using only the rudder angle. Decide to avoid it.

1.2. How to acquire remote control data

Remote control data is obtained in the following five steps using the remote control procedure in Figure 1 (A).

Step 1: Ship control data (S-data) including ship control results and navigation conditions is transmitted to the transmitter (STx) at time T1 and received by the receiver (CRx) at time T2. Delay occurs during this data transmission and reception process.

Step 2: Enter the S-data received at time T2 into the remote control device to visualize the navigation situation at time T1, and the remote controller performs remote control while viewing the navigation situation at T1 to generate control data (C-data). After that, input it to the transmitter (CTx) at time T2. During this control process, a response delay of the remote controller occurs.

Step 3: At time T3, C-data is transmitted through the transmitter (CTx) and at time T4, the ship receives C-data. Delay occurs during this data transmission and reception process.

Step 4: The ship is controlled using the C-data input at time T4, and the ship control data (S-data) including the control result and navigation situation is input to the transmitter (STx) at time T1. During this ship control process, ship response delays occur.

Step 5: As in Step 1, S-data is transmitted to the transmitter (STx) at time T1 and received by the receiver (CRx) at time T2.

Remote control data is stored in the DB in the form of three types of data {S-data, C-data, T-data} that are generated from time to time while continuously repeating the above 5-step process, where T-data is time It represents data, and the times included in the time data are times measured using GPS (Global Positioning System) during the transmission and reception of S-data and C-data.

S-data is composed of the following set of information. The OS (Own Ship) and TS (Target Ship) preceding the English letters are used to identify the own ship and other ships, respectively.

S-data{OS-MMSI, ship identification number; OS-time, main line time; OS-position, ship position; OS-heading, final heading; OS-speed, own ship speed; OS-rudder-angle, main line angle; OS-Radar, own ship radar image data; OS-ECDIS, main line ECDIS video information; OS-CCTV, main line CCTV video data; TS-MMSI, batting line identification number; TS-time, batting time; TS-position, batting line position; TS-heading, batting line direction; TS-speed, batting line speed}.

In addition, C-data consists of the following set of information.

C-data{C-time, control command occurrence time; C-speed, control speed; C-heading, controlled heading; C-rudder-angle, control angle}.

And T-data consists of the following set of information.

T-data{T1, vessel data transmission time; T2, vessel data reception time; T3, control data transmission time; T4, control data reception time}.

Here, delays occur in the remote control process of autonomous ships, and these delays include changes in hull response delay due to changes in the navigation environment (wind, waves, sailing, etc.), communication network status (communication speed, communication time depending on data capacity) etc.) and changes in the remote controller's response delay depending on the navigation situation, etc., fluctuate over time at each stage.

If a delay that varies over time occurs during the remote control process, the remote controller fails to recognize the navigation situation and remote control fails. For example, if the navigation situation of a ship transmitted at time T1 is delayed and becomes visible at time T2, the remote controller may fail to recognize the navigation situation because it sees the navigation situation at T1. In addition, taking remote control failure as an example, if the control command of the remote controller transmitted at time T3 is delayed and is delivered to the ship at time T4, control may fail because the ship receives the control command at time T3.

In addition, if a collision situation occurs due to the above delay during the remote control process, a problem arises in which the remote controller must use the situation at time T1 to avoid collision by considering the control command delivered to the ship at time T4. To solve the problem, the collision avoidance start time must first be estimated.

1.3. How to estimate the start time of collision avoidance

If a delay occurs in remote control, the remote controller's control angle for collision avoidance must also be determined considering the navigation situation expected to change after the delayed time. To do this, first, it is necessary to know the time at which the control rudder angle is effectively applied to ship control and collision avoidance begins after the delayed time.

The method of estimating the start time of collision avoidance is explained using FIG. 2. Figure 2 shows three types of control states that can occur depending on time in the (A) remote control procedure shown in Figure 1 above. The three types of control states are a control state of n-1, which means a certain point in the past, The control state of n refers to the present time and the control state of n+1 refers to some point in the future. The upper part of the diagram shows the movement of a ship in each control state as it moves along the planned course, the lower part shows the time of remote control data transmission and reception and the remote operator (operator) at that time, and the first part of the diagram shows the movement of each control state when the ship moves along the planned course. The part below divides the remote controller (Operator(n)) into n control states into known states and unknown states.

First, the collision avoidance process will be explained using the control states shown in [Control target area] of FIG. 2. Collision avoidance occurs when the remote controller recognizes the navigation situation (Situation(n)) of the vessel at T1(n) in n control state and then transmits the control rudder angle to the vessel estimated to be at T4(n+1). It is performed when the ship response starts at (n+1). Therefore, the start time of collision avoidance is T1(n+1). Based on the remote controller (Operator(n)), T1(n) and T2(n) can be known, but from T2(n) to T1( n+1) are times that have not occurred yet, so we do not know.

The collision avoidance start time is based on the operator (n) in the n control state and is based on five types of times (T2 (n-1), T3 (n), T4 (n), T1 (n) measured using GPS in the past. ), T2(n)) is used to estimate. The meaning of the 5 types of time is as follows.

T2(n-1): Time when the remote controller receives ship data (S-data) in n-1 state

T3(n): Time when the remote controller transmits control data (C-data) in n state

T4(n): Time when control data (C-data) is received from the ship in n state

T1(n): Time when ship data (S-data) is transmitted from the ship in n state

T2(n): Time when the remote controller receives ship data (S-data) in n state

1.4. How to estimate the collision angle range

After the collision avoidance start time T1(n+1) is estimated using 5 types of times (T2(n-1), T3(n), T4(n), T1(n), T2(n)), The control angle at which collision avoidance can be successfully avoided at T1(n+1) must be determined at T2(n), and this control angle is other than the steering angle at which collision avoidance can fail (i.e., the collision angle). Here, the rudder angle for collision avoidance (collision avoidance rudder angle) is determined by the remote controller within the range of rudder angles allowed by the ship. This is because the rudder angle for collision avoidance varies depending on navigation conditions, control delays, etc., so optimal collision avoidance is achieved. This is because the angle of attack cannot be determined.

Therefore, the important thing in remote control is not to provide the remote controller with a steering angle for collision avoidance, but to provide a collision angle at which collision avoidance may fail as well as a range of collision angles that reflect the navigation situation and control delay.

The range of collision attack angle is estimated using a previously constructed turning circle domain in a time and space (TC-domain). Here, the turning time-space domain is implemented using the ship's turning circle. The turning circle refers to the traces of the position that appears when the ship turns in response to the control rudder angle, and the turning time-space domain is the rudder angle ( It refers to the space-time expressed in x-y plane coordinates of the turning circle for the combination of rudder angle and time.

The method of constructing the orbital space-time domain is explained using FIG. 3. Figure 3 shows the configuration of the turning space-time domain, where the x-axis and y-axis represent the x-axis and y-axis distance of the turning circle in meters, respectively, and the time shown above the x-axis and to the left of the y-axis represents the turning time (t). OS(0,0) represents the x-y coordinate origin (0,0), and this origin represents the ship's position when receiving the control rudder angle at T4(n+1). Therefore, the turning time and space represents the position of the turning circle that may appear at a time after T4(n+1). In addition, the ship's course is shown by fixing the y-axis direction to the heading zero (0) degrees, regardless of the actual course. The reason is that the positional relationship between the ship and other ships that meet each other in various ways is simplified by fixing the ship's course. To indicate clearly, the position of the batting line is displayed relative to the home line.

The curves indicated by eight dotted lines represent the turning circle (TC) according to time increase based on OS(0,0) as a combination of x-y positions, and the semicircle shown by six solid lines represents the turning circle (TC) in combination with time and distance. It represents the Time-Distance Line (TDL). In addition, the number shown in the outermost semicircle represents the rudder angle (deg.), which indicates the rudder angle used on the starboard side from 0 degrees to 35 degrees, and the rudder angle used on the port side is a portion of 0 degrees to 10 degrees. This is intended to reflect the International Collision Prevention Regulations at Sea (COLREGs), which mainly apply the starboard rudder angle for collision avoidance.

Figure 4 illustrates a method of estimating the collision angle range using the turning space-time domain, in which the other ship (TS) sails in a direction of 270 degrees (i.e., from starboard to port based on the coordinate origin) with respect to the main ship (OS). It is assumed that

The range of impact angle is calculated as follows. (1) At the collision avoidance start time (T1(n+1)) of the own ship, set the own ship's position as OS(0,0), calculate the relative position of the other ship at this time and set it as TS(x,y), (2) ) Using the control rudder angle commanded by the remote controller, calculate the position that the other ship moved along the course (TS-course) during the turn time (t) of the main ship, and (3) according to the control rudder angle (d) of the remote controller. After finding the turning circle (TC(d)) and the location where the rudder collides (PSN-Col), all rudder angles included within the collision circle (CC) with radius r are derived from (4) PSN-Col. Then, the maximum and minimum values among these are determined as the upper limit (RA-Upper) and lower limit (RA-Lower) of the collision angle range.

2. Implementation means for estimating the impact angle range

Estimation of the collision angle range is implemented through the following nine steps.

Step 1: Construction of orbital space-time domain

The turning time-space domain (TC-domain) is established in advance using the ship's turning circle (TC) before conducting remote control. First, TC gives the conditions of the following equation (1) to the ship's ship-model and obtains it in the x-y plane coordinate system.

TC(x,y,v,d) = [Ship-model | v,d] ---------------------------------- (1)

Here, v represents the allowable speed of the ship, v = v-min,… v-max (v-min is the minimum speed, v-max is the maximum speed), and d represents the allowable rudder angle of the ship, d = 1,2,… d-max (d-max is the maximum allowable steering angle, generally around 30 degrees).

The TC-domain is constructed using the TC when the conditions of the following equation (2) are given in the above equation (1).

TC-domain(x,y,v,d,t) = [TC(x,y,v,d) | t] -------------------------- (2)

Here, t represents the turning time of the ship, t = 0,… TC-time (TC-time is the time required for one turn).

Step 2: Acquire control point data in the current control state

The control time data is the time (T2(n)) when the remote controller received the ship data in n control state using time data (T-data) among the three types of data stored in DB from time to time during the remote control process. The time data (T2-data(n,m)) based on is obtained by configuring it in the form of an n×m matrix as follows.

T2-data(n,m) ∈ {T2(n-1), T3(n), T4(n), T1(n), T2(n)}

Here, n is the control state identification number, where n = 1, 2,… N (N is the final control state), and m is the data number, where m=1,2,... M (M is the total number of data, M=5), and each time is measured using GPS time for time synchronization between the ship and the remote controller.

Step 3: Estimation of collision avoidance start time

The collision avoidance start time T1(n+1) is calculated using the delay time (DT) between T2(n-1) and T2(n) occurring in the n-1 control state and the n control state, using the following equation (3) ) is estimated.

T1(n+1) = T1(n) + DT ------------------------------------- --------- (3)

Here, DT is calculated using the following equation (4).

DT = DT-T12 + DT-T23 + DT-T34 + DT-T41 ---------------------------- (4)

Here, the four terms on the right represent the delay time (DT) calculated using equations (5) to (8) below.

DT-T12 = T2(n) - T1(n) ------------------------------------- ------- (5)

DT-T23 = T3(n) - T2(n-1) -------------------- ------- (6)

DT-T34 = T4(n) - T3(n) ------------------------------------- ------- (7)

DT-T41 = T1(n) - T4(n) ------------------------------------- ------- (8)

Step 4: Calculate vessel position from collision avoidance start time

At the collision avoidance start time T1(n+1), the own ship position OS-T1(n+1) and the other ship position TS-T1(n+1) are calculated using the following equations (9) and (10), respectively. .

OS-T1(n+1) = OS-T1(n)) + OS-del(x,y) ------------------------- ----- (9)

TS-T1(n+1) = TS-T1(n)) + TS-del(x,y) ------------------------- ---- (10)

Here, OS-T1(n) and TS-T1(n) represent the positions obtained by converting the home ship position and the other ship position measured using GPS at time T1(n) into an x-y plane coordinate system with meter units, respectively, and OS -del(x,y) and TS-del(x,y) indicate the position to which the main ship or other ships moved during the delay time (DT), and their x-axis and y-axis values are expressed in the following equation (11) ) and equation (12).

x = v×sin(course)×DT ---------------------------------------- --- (11)

y = v×cos(course)×DT ---------------------------------------- --- (12)

Here, v and course represent the speed and heading of the main line (or other line), respectively.

Step 5: Determination of need for collision avoidance

The need for collision avoidance is determined when the relative distance (DT) between two ships at T1(n+1) is small compared to the reference relative distance (RD-ref). Collision avoidance is determined using the following algorithm: if Col = 1, collision avoidance is necessary, and if Col = 0, collision avoidance is not necessary.

if (RD ≤ RD-ref) then, Col = 1 else, Col = 0

Here, RD-ref is a value determined through experiment and statistics, and is generally set at 3.25 times the ship length, and RD is calculated using the following equation (13).

RD = sqrt[ (OS-x - TS-x)^2 + (OS-y - TS-y)^2 ] ----------------- (13)

Here, sqrt represents the square root, and OS-x, TS-x, OS-y, and TS-y are the x-axis value of OS, the x-axis value of TS, the y-axis value of OS, and TS. Indicates the y-axis values of .

Step 6: Calculate collision time by vessel turn

At T1(n+1), when the ship turns using the remote controller's control angle, the collision time with the other ship is obtained using the turning time-space domain. The collision time is when the main ship moves during the turning time (t) using the control rudder angle of d in the turning time and space, TC-domain(x,y,v,d,t) and TS(x,y,t) is set as the turning time (t) that coincides with each other. Collision time (Col-time) is calculated using the following conditional equation (14).

Col-time = [t|TC-domain(x,y,v,d,t)-TS(x,y,t)=0], (0≤t< TC-time) - (14)

Here, TS(x,y,t) represents the position the other ship moved during the turning time (t), and the x-axis and y-axis values are calculated using the following equations (15) and (16), respectively. do.

x = v×sin(course)×t ---------------------------------------- ---- (15)

y = v×cos(course)×t ---------------------------------------- ---- (16)

Step 7: Calculate collision location

The collision location (PSN-Col) is determined as the location corresponding to the collision time (Col-time) in the orbit time-space domain, and is calculated using the following conditional equation (17).

PSN-Col(x,y) = [(x,y) | TC-domain(x,y,v,d,t)(t=Col-time)] -------- (17)

Step 8: Calculate the range of impact angle

The range of the collision angle is obtained from the collision location (PSN-Col) using a collision circle (CC) with a radius (r) and an arc angle of theta (theta = 0,1.2,… 2×3.14). First, calculate x(theta) and y(theta) of CC(x,y,theta) using the following equations (18) and (19), respectively.

x(theta) = [r×sin(theta)] + [x | Col-psn(x,y)] ------------------ (18)

y(theta) = [r×cos(theta)] + [y | Col-psn(x,y)] ------------------ (19)

Here, the radius r is determined through experiment and statistics, and is generally set as the radius of a circle that can be secured from 3.25 times the length of the ship to 1.0 times the width of the ship. In addition, the radius r varies depending on delay time, navigation environment, ship specifications, etc.

Then, the range of the collision angle (Col-RA-range) is determined using all the steering angles (d) included in CC, and this steering angle is calculated using the following conditional equation (20).

Col-RA-range(theta)=[d(theta)|TC-domain(x,y,v,d,t)≤CC(x,y,theta)]-(20)

And the upper limit (RA-Upper) and lower limit (RA-Lower) of the collision angle range are determined by the maximum and minimum values, respectively, of the Col-RA-range (theta).

Step 9: Determination of collision risk based on remote controller's control angle

The collision risk for the remote controller's control rudder angle (C-rudder-angle) is determined using the following algorithm.

if (RA-Lower ≤ C-rudder-angle ≤ RA-Upper) then, RW = 1, else RW = 0

Here, RW indicates whether there is a collision risk warning (Rudder Warning) of the control rudder angle. If RW = 1, it is dangerous because the control rudder angle (C-rudder-angle) is within the range of the collision angle (RA-Lower, RA-Upper). and RW=0 indicates safety.

3. How to visualize the impact angle range

A method of visualizing the range of collision angles (RA-Lower, RA-Upper) is explained using FIGS. 5 and 6. Figure 5 shows a configuration diagram of a collision angle range visualization window, and Figure 6 shows an example of impact impact angle range visualization.

In Figure 5, the upper semicircle (RUDDER ANGLE RANGE (degree)) is a part that visualizes the control angle of the remote controller and the estimated collision angle range, and the long rectangular box below (RUDDER ANGLE RANGE (Order) (degree)) is the part that visualizes the remote controller's control angle and the estimated collision angle range. This is the part that visualizes only the controller's control angle. Through this screen, the remote controller can easily see the collision risk of the control angle he or she is applying.

In more detail, (1) is a display box for the lower and upper limits of the collision angle, where S/P indicates starboard (S, starboard) or port (P, port), and DD.d ( DD represents 2 degrees, and d represents 1/10 of a degree. (2) is a visualization window of the collision angle range, and the numbers from 0 to 35 represent the starboard or port rudder angle. (3) represents the range of the collision angle visualized in orange, (4) represents the control angle of the remote controller visualized in blue, (5) is the control angle display box expressed in degrees (DD.d), ( 6) is a control angle display window shown in the form of a bar graph, and (7) is a box to warn of the risk of collision at the control angle in two colors (blue and red), with blue indicating safety and red indicating danger.

Figure 6 shows an example of visualization of the impact angle range, which assumes the following situation. The remote controller's control rudder angle is 25.0 degrees to starboard, and 25.0 degrees to starboard corresponds to the collision angle range between 19.6 degrees to starboard and 31.5 degrees to starboard, so the rudder warning is displayed in red to alert the remote controller to the current control rudder angle. It is a warning that a conflict may occur if applied to avoidance. Conversely, if the control rudder angle does not fall within the collision angle range, the rudder warning is displayed in blue to indicate that it is safe.

Through visualization of this collision angle range, the remote controller can easily recognize the collision risk of the control angle that he or she is applying for collision avoidance, as well as prevent collisions by identifying the range of control angle where a collision can occur. .

Meanwhile, the present invention is not limited to the described embodiments, and can be used by changing the application area, and various modifications and variations can be made without departing from the spirit and scope of the present invention. It is self-evident to those with knowledge. Accordingly, such variations or modifications should fall within the scope of the claims of the present invention.

Claims (17)

Obtaining and storing all remote control data generated during the control process, the remote controller is a remote control device consisting of a remote control device, a transmitting and receiving device (STx, CRx, CTx, SRx), and a communication network (LTE, LTE-M, V-SAT). A remote control procedure that continuously and repeatedly controls a ship (MASS) using a control system and stores all remote control data generated during this control process in a database, and estimates collision avoidance time by calling the obtained remote control data. A collision risk warning step of the control angle, which is performed through a process of estimating and visualizing the range of the collision angle to determine whether collision avoidance is necessary;
A remote control data acquisition step due to delays occurring in the data transmission and reception process, response delays of the remote controller in the control process, and response delays of the ship in the ship control process;
A collision avoidance start time estimation step for estimating the time at which the control rudder angle is effectively applied to ship control after the delayed time and collision avoidance starts;
An estimation step of the collision angle range for estimating the range of the collision angle that reflects the collision angle at which collision avoidance may fail and the navigation situation and control delay;
A process of constructing a turning time-space domain, a process of acquiring control point data in the current control state, a process of estimating the collision avoidance start time, a process of calculating the ship position at the start time of collision avoidance, a process of determining the need for collision avoidance, and turning the ship. An implementation step of collision angle range estimation consisting of a collision time calculation process, a collision position calculation process, a collision radius calculation process, and a collision risk determination process for the remote controller's control angle;
Estimation of the collision risk angle range using the turning time-space domain for collision prevention in remote control of autonomous ships, characterized in that it consists of a visualization step of the collision angle range consisting of the control angle, the estimated collision angle range, and the remote controller's control angle. and visualization methods. delete The method of claim 1, wherein the process of estimating and visualizing the range of the collision avoidance angle includes estimating the collision avoidance start time by calling remote control data from a database storing remote control data generated during the control process; and the estimated collision avoidance start time. The relative distance between the main ship (MASS) and other ships (other ships or objects subject to collision avoidance) is calculated to determine whether collision avoidance is necessary; if it is determined that collision avoidance is necessary, the ship turns according to the control rudder angle. In this case, the location where a collision may occur with another ship is determined using the turning space-time domain; the range of the collision rudder angle and the collision risk level of the control rudder angle are evaluated and determined, and then visualized to warn of the risk of collision. A method of estimating and visualizing the collision risk angle range using the turning space-time domain to prevent collisions in remote control of autonomous ships. The method of claim 1, wherein the remote control data acquisition step is performed using the following (method 1): Estimation of the collision risk angle range using the turning space-time domain to prevent collision in remote control of autonomous ships, and Visualization method.
(method 1)
1) At time T1, ship control data (S-data) including ship control results and navigation status is transmitted to the transmitter (STx) and received at time T2 by the receiver (CRx).
2) The S-data received at time T2 is input to the remote control device to visualize the navigation situation at time T1, and the remote controller performs remote control while viewing the navigation situation at T1 to generate control data (C-data). After input to the transmitter (CTx) at time T2.
3) At time T3, C-data is transmitted through the transmitter (CTx), and at time T4, the ship receives C-data.
4) The ship is controlled using C-data input at time T4, and ship control data (S-data) including the control results and navigation status is input to the transmitter (STx) at time T1.
5) Similar to 1) above, S-data is transmitted to the transmitter (STx) at time T1 and received by the receiver (CRx) at time T2. According to claim 4, the remote control data is stored in the DB in the form of three types of data {S-data, C-data, T-data} that are generated from time to time while continuously repeating the above 5 processes; ,
The T-data includes T1, ship data transmission time; T2, vessel data reception time; T3, control data transmission time; T4 indicates time data consisting of control data reception time. The times included in the time data are times measured using GPS during the transmission and reception of S-data and C-data.
The S-data includes OS-MMSI, ship identification number; OS-time, main line time; OS-position, ship position; OS-heading, final heading; OS-speed, own ship speed; OS-rudder-angle, main line angle; OS-Radar, own ship radar image data; OS-ECDIS, main ship ECDIS video information; OS-CCTV, main line CCTV video data; TS-MMSI, batting line identification number; TS-time, batting time; TS-position, batting line position; TS-heading, batting line direction; Includes one or more of TS-speed and batting line speed,
The C-data is C-time, control command generation time; C-speed, control speed; C-heading, controlled heading; A method for estimating and visualizing the collision risk rudder angle range using the turning space-time domain to prevent collisions in remote control of autonomous ships, which includes one or more of C-rudder-angle and control rudder angle. The method of claim 1, wherein in the collision avoidance start time estimation step, the collision avoidance start time is measured in the past using GPS based on Operator (n) in the n control state,
T2(n-1): Time when the remote controller receives ship data (S-data) in n-1 state;,
T3(n): Time when the remote controller transmits control data (C-data) in n state;,
T4(n): Time when control data (C-data) is received from the ship in n state;,
T1(n): Time when ship data (S-data) is transmitted from the ship in n state;,
T2(n): Time when the remote controller receives ship data (S-data) in n state;,
Collision in remote control of autonomous ships, characterized in that it is estimated using five types of times (T2(n-1), T3(n), T4(n), T1(n), T2(n)). For prevention purposes, a method of estimating and visualizing the collision risk range using the turning space-time domain. According to claim 1, in the step of estimating the collision angle range, the collision angle range is a turn implemented using the ship's turning circle (trajectory of the position that appears when the ship turns in response to the control rudder angle) established in advance. It is estimated by applying the space-time domain (space-time showing the turning circle in xy plane coordinates for the combination of rudder angle and time), and the method of constructing the turning space-time domain is using (method 2) below. A method for estimating and visualizing the collision risk angle range using the turning space-time domain to prevent collisions in remote control of autonomous ships, characterized by:
(method 2)
The x-axis and y-axis represent the x- and y-axis distances of the turning circle in meters, respectively, and the time shown above the x-axis and to the left of the y-axis represents the turning time (t).
The ship (0,0) represents the xy coordinate origin (0,0), and this origin represents the ship's position when receiving the control rudder angle at T4(n+1).
The turning time and space indicates the position of the turning circle that may appear at a time after T4(n+1).
The ship's course is indicated by fixing the y-axis direction to the heading zero (0) degrees, regardless of the actual course.
Based on the main ship (0,0), the turning circle (TC) according to the increase in time is displayed as a curve with 8 dotted lines for the combination of xy positions, and the turning circle's time-distance line is a combination of time and distance. Line, TDL) is displayed as six solid lines.
The number shown in the outermost semicircle represents the rudder angle (deg.). The rudder angle used on the starboard side is from 0 degrees to 35 degrees, and the rudder angle used on the port side is only a portion of the range from 0 degrees to 10 degrees. indicates. According to claim 1, in the process of constructing the turning time-space domain, the turning time-space domain (TC-domain) is established in advance using the turning circle (TC) of the ship before remote control is performed, and the TC is The conditions of Equation (1) below are given to the ship's ship control model (Ship-model), obtained in the xy plane coordinate system, and the conditions of Equation (2) below are given to Equation (1). Constructed using TC A method for estimating and visualizing the collision risk angle range using the turning space-time domain to prevent collisions in remote control of autonomous ships, characterized by:
Formula (1) TC(x,y,v,d) = [Ship-model | v,d]
Here, v represents the allowable speed of the ship, v = v-min,… v-max (v-min is the minimum speed, v-max is the maximum speed), and d represents the allowable rudder angle of the ship, d = 1,2,… d-max (d-max is the maximum allowable steering angle, generally around 30 degrees).
Formula (2) TC-domain(x,y,v,d,t) = [TC(x,y,v,d) | t]
Here, t represents the turning time of the ship, t = 0,… TC-time (TC-time is the time required for one turn). According to claim 1, in the process of acquiring control point data in the current control state, the control point data is n-controlled using time data (T-data) among three types of data stored in the database from time to time during the remote control process. In this state, the time data (T2-data(n,m)) based on the time (T2(n)) at which the remote controller received the ship data is obtained by configuring it in the form of an n×m matrix as follows. A method of estimating and visualizing the collision risk angle range using the turning space-time domain to prevent collisions in remote control of autonomous ships.
T2-data(n,m) ∈ {T2(n-1), T3(n), T4(n), T1(n), T2(n)}
Here, n is the control state identification number, where n = 1, 2,… N (N is the final control state), and m is the data number, where m=1,2,... M (M is the total number of data, M=5), and each time is measured using GPS time for time synchronization between the ship and the remote controller. The method of claim 1, wherein in the estimation process of the collision avoidance start time, the collision avoidance start time T1(n+1) is calculated from T2(n-1) occurring in the n-1 control state and the n control state. Collision risk using the turning time-space domain to prevent collision in remote control of autonomous ships, which is characterized by estimating using the following equation (3) to (8) using the delay time (DT) between Method for estimating and visualizing the steering angle range.
Formula (3) T1(n+1) = T1(n) + DT
Here, DT is calculated using equation (4) below.
Formula (4) DT = DT-T12 + DT-T23 + DT-T34 + DT-T41
Here, the four terms on the right represent the delay time (DT) calculated using equations (5) to (8) below.
Formula (5) DT-T12 = T2(n) - T1(n)
Formula (6) DT-T23 = T3(n) - T2(n-1)
Formula (7) DT-T34 = T4(n) - T3(n)
Formula (8) DT-T41 = T1(n) - T4(n) The method of claim 1, wherein the vessel position calculation process at the collision avoidance start time is: the own ship position OS-T1(n+1) and the other ship position TS-T1(n+) at the collision avoidance start time T1(n+1). 1) is a method for estimating and visualizing the collision risk angle range using the turning space-time domain for collision prevention in remote control of autonomous ships, which is calculated using the following equations (9) to (12).
Formula (9) OS-T1(n+1) = OS-T1(n)) + OS-del(x,y)
Formula (10) TS-T1(n+1) = TS-T1(n)) + TS-del(x,y)
Here, OS-T1(n) and TS-T1(n) represent the positions obtained by converting the main ship position and the other ship position measured using GPS at time T1(n) into the xy plane coordinate system with meter units, respectively, and OS -del(x,y) and TS-del(x,y) indicate the position to which the main ship or other ships moved during the delay time (DT), and their x-axis and y-axis values are expressed in the following equation (11) ) and equation (12).
Formula (11) x = v×sin(course)×DT)
Formula (12) y = v×cos(course)×DT
Here, v and course represent the speed and heading of the main line (or other line), respectively. According to claim 1, in the process of determining the need for collision avoidance, the need for collision avoidance is determined when the relative distance (DT) between the two ships at T1 (n+1) is smaller than the reference relative distance (RD-ref). However, collision avoidance is determined using the algorithm (1) below to determine that collision avoidance is necessary if Col = 1, and that collision avoidance is not necessary if Col = 0. Collision prevention in remote control of autonomous ships For this purpose, a method for estimating and visualizing the collision risk range using the turning space-time domain.
Algorithm (1) if (RD ≤ RD-ref) then, Col = 1 else, Col = 0
Here, RD-ref is a value determined through experiment and statistics, and is generally set at 3.25 times the ship length, and RD is calculated using the formula (13) below.
Formula (13) RD = sqrt[ (OS-x - TS-x)^2 + (OS-y - TS-y)^2 ]
Here, sqrt represents the square root, and OS-x, TS-x, OS-y, and TS-y are the x-axis value of OS, the x-axis value of TS, the y-axis value of OS, and TS. Indicates the y-axis values of . According to claim 1, in the process of calculating the collision time due to the main ship turning, when the main ship turns using the control rudder angle of the remote controller at T1(n+1), the collision time with the other ship is derived using the turning time-space domain. In other words, the collision time is the TC-domain(x,y,v,d,t) and TS(x,y) when the main ship moves during the turning time (t) using the control rudder angle of d in the turning time and space. ,t) is set as the turning time (t) that coincides with each other. Collision time (Col-time) is calculated using the conditional formula (14) below.
Formula (14) Col-time = [t | TC-domain(x,y,v,d,t) - TS(x,y,t) = 0], (0≤t< TC-time)
Here, TS(x,y,t) represents the position the other ship moved during the turning time (t), and the x-axis and y-axis values are calculated using the following equations (15) and (16), respectively. Calculate.
Formula (15) x = v×sin(course)×t
Formula (16) y = v×cos(course)×t According to claim 1, in the process of calculating the collision position, the collision position (PSN-Col) is determined as a position corresponding to the collision time (Col-time) in the turning time-space domain, using the following conditional equation (17). A method for estimating and visualizing the collision risk angle range using the turning space-time domain for collision prevention in remote control of autonomous ships, which is characterized by calculating.
Formula (17) PSN-Col(x,y) = [(x,y) | TC-domain(x,y,v,d,t)(t=Col-time)] According to claim 1, in the process of calculating the range of the collision angle, the range of the collision angle is the arc angle of the radius (r) and theta (theta = 0, 1.2,... 2×3.14) at the collision location (PSN-Col). It is obtained using a collision circle (CC) with . First, calculate x(theta) and y(theta) of CC(x,y,theta) using Equation (18) and Equation (19) below, respectively, and calculate the range of collision angle (Col-RA-range) is determined using all rudder angles (d) included in CC, and this rudder angle is calculated using the conditional formula (20) below. In order to prevent collisions in remote control of autonomous ships, the turning space-time domain is used. Estimation and visualization method of collision risk range.
Formula (18) x(theta) = [r×sin(theta)] + [x | Col-psn(x,y)]
Formula (19) y(theta) = [r×cos(theta)] + [y | Col-psn(x,y)]
Here, the radius r is determined through experiment and statistics, and is generally set as the radius of a circle that can be secured from 3.25 times the length of the ship to 1.0 times the width of the ship. In addition, the radius r varies depending on delay time, navigation environment, ship specifications, etc.
Formula (20) Col-RA-range(theta) = [d(theta) | TC-domain(x,y,v,d,t) ≤ CC(x,y,theta)]
And the upper limit (RA-Upper) and lower limit (RA-Lower) of the collision angle range are determined by the maximum and minimum values, respectively, of the Col-RA-range (theta). The method of claim 1, wherein in the process of determining the collision risk for the control angle of the remote controller, the collision risk for the control angle (C-rudder-angle) of the remote controller is determined using the following algorithm (2). A method for estimating and visualizing the collision risk angle range using the turning space-time domain to prevent collisions in remote control of autonomous ships, characterized by:
Algorithm (2) if (RA-Lower ≤ C-rudder-angle ≤ RA-Upper) then, RW = 1,else RW = 0
Here, RW indicates whether there is a collision risk warning (Rudder Warning) of the control rudder angle. If RW = 1, it is dangerous because the control rudder angle (C-rudder-angle) is within the range of the collision angle (RA-Lower, RA-Upper). and RW=0 indicates safety. The method of claim 1, wherein, in the step of visualizing the collision angle range, a display area that visualizes the control angle of the remote controller and the estimated collision angle range, a display area that visualizes only the control angle of the remote controller, and a lower limit value of the collision angle ( Collision prevention in remote control of autonomous ships, characterized in that it consists of one or more of the lower (Lower), upper limit (Upper), starboard (S, starboard) or port (P, port) angles and includes a visibility window. For this purpose, a method for estimating and visualizing the collision risk range using the turning space-time domain.