A three-dimensional safety situation awareness method and system based on ship motion response

Abstract

The application discloses a three-dimensional safety situation awareness method and system based on ship motion response, and the method comprises the following steps: acquiring ship data and environment data, wherein the ship data comprises distress ship data and rescue ship data, and inputting a ship motion model to acquire motion state parameters of the ship; inputting the motion state parameters into a three-dimensional dynamic ship field model, and outputting a final three-dimensional safety situation awareness result through coupling calculation of multidimensional danger degree factors. According to the four-degree-of-freedom nonlinear state space equation and the drift state space equation, the motion state parameters of the distress ship and the rescue ship are acquired, the motion state of the rescue ship and the distress ship in the three-dimensional space is accurately analyzed, the collision danger degree is calculated through the coupling calculation of the multidimensional danger degree factors, the collision danger degree calculation is fused with the time, space constraint and rolling influence, the collision risk in the rescue process can be accurately quantified, and the accuracy of risk assessment is provided.

Description

Technical Field

[0001] This invention relates to the field of maritime emergency rescue technology, and in particular to a three-dimensional safety situation cognition method and system based on ship motion response. Background Technology

[0002] Waterway transportation, as a core link in global trade and regional economic connectivity, plays a strategic role in national economic development through its safe and efficient operation. Maritime emergency rescue safety, a crucial component of waterway transportation safety assurance, heavily relies on accurate understanding of the situation at the rescue site. This requires analyzing the dynamic coupling relationship between environmental disturbances and ship motion responses, quantifying collision risks between ships, and dynamically analyzing the safety situation at the rescue site. It is an indispensable support link in the waterway transportation safety assurance system. Currently, mainstream technologies for safety situation assessment mostly employ two-dimensional planar models (such as the ship domain model proposed by Fujii and Goodwin), determining the planar safety domain through geometric relationships to quantify collision risks. While these models are widely used in conventional ship navigation, they simplify three-dimensional ship motion to a planar projection, ignoring vertical movements such as roll and pitch. This presents significant limitations in maritime emergency rescue scenarios—the roll motion of a distressed vessel can lead to significant changes in attitude and draft. Rescue vessels need to formulate rescue plans based on the vessel's real-time three-dimensional motion state, and traditional two-dimensional models cannot accurately quantify three-dimensional collision risks, failing to meet the high-precision requirements of rescue scenarios. In addition, existing three-dimensional situational awareness technologies are mostly static geometric superpositions of "planar + vertical" (such as three-dimensional ship domain models in bridge area waters), which do not fully consider the dynamic impact of ship motion on safety boundaries, and are also unable to adapt to the scenario requirements of close-range dynamic interaction between ships in emergency rescue. Summary of the Invention

[0003] To address the shortcomings of existing technologies in accurately quantifying collision risks in three-dimensional space and insufficient consideration of the dynamic impact of ship motion on safety boundaries, this invention provides a three-dimensional safety situation cognition method and system based on ship motion response, enabling precise analysis of the motion states of rescue vessels and distressed vessels in three-dimensional space and quantification of collision risks.

[0004] Therefore, the technical solution adopted by the present invention is as follows: A three-dimensional safety situation awareness method based on ship motion response is provided, the method comprising: The system acquires ship data and environmental data, including data on distressed vessels and rescue vessels, and inputs them into the ship motion model to obtain the ship's motion state parameters. Specifically, the ship motion model obtains the real-time motion vector of the rescue vessel through a four-degree-of-freedom nonlinear state-space equation and obtains the drift motion vector of the distressed vessel through a drift state-space equation. The motion state parameters are input into a three-dimensional dynamic ship domain model, and the final three-dimensional safety situation perception result is output through the coupled calculation of multi-dimensional hazard factors; among which the multi-dimensional hazard factors include time collision hazard, spatial collision hazard and roll collision hazard.

[0005] According to the above scheme, the distressed vessel data includes a distressed vessel state vector describing the vessel's position, attitude, speed, and angular velocity; the distressed vessel drift state space equation is specifically solved based on the distressed vessel data and environmental data to determine the rate of change of the distressed vessel's motion state over time.

[0006] According to the above scheme, the three-dimensional dynamic ship domain model is specifically constructed based on the three-dimensional ellipsoidal ship domain. The length of the horizontal semi-major axis of the three-dimensional ellipsoid is specifically calculated based on the fixed semi-major axis length, speed, and roll angle of the ship when it is stationary and without rolling. The length of the horizontal semi-minor axis of the three-dimensional ellipsoid is specifically calculated based on the fixed semi-minor axis length, speed, and roll angle of the ship when it is stationary and without rolling. The length of the vertical semi-axis of the three-dimensional ellipsoid is specifically calculated based on the ship's draft.

[0007] According to the above scheme, the results of three-dimensional security situation awareness are obtained in the following ways: Calculate the distance between the nearest points on the surface of the three-dimensional ellipsoidal vessel domain for distressed and rescue vessels; The time hazard factor, spatial hazard factor, and roll hazard factor are calculated based on the distance to the nearest point on the surface. The collision hazard is then calculated by multiplying the time hazard factor, spatial hazard factor, and roll hazard factor together to obtain the final safety situation assessment result.

[0008] According to the above scheme, the four-degree-of-freedom nonlinear state-space equations specifically calculate the rate of change of the rescue ship's motion state over time using the system matrix, control input matrix, disturbance input matrix, system state vector, control input vector, and environmental disturbance vector. The system status includes longitudinal and lateral velocities, bow and roll angular velocities, x-axis and y-axis accelerations, bow angular accelerations, and roll angular accelerations; the control input vectors are specifically the rudder angle and propeller speed of the rescue vessel.

[0009] According to the above scheme, the distressed vessel data specifically refers to the motion data of the distressed vessel in a completely out-of-control state. The drift state space equation is specifically calculated based on the ship system state matrix, input matrix, output matrix, distressed vessel state vector, and environmental disturbance input vector to calculate the output vector and the rate of change of the distressed vessel's motion state over time. The motion state of a distressed vessel includes its longitudinal velocity, lateral velocity, bow roll rate, roll rate, acceleration along the x-axis and y-axis, and bow turn acceleration. The distressed vessel's state vector includes the distressed vessel's roll angle, bow angle, longitudinal and lateral displacements in the geodetic coordinate system, and the distressed vessel's drift velocity and bow angular velocity along the x and y axes in the ship's coordinate system. The input vector includes the velocities of the flow, wind, and waves in the x and y directions.

[0010] According to the above scheme, the rate of change of the distressed vessel's motion state over time includes the rate of change of position, the rate of change of bow angle, the rate of change of roll angle, and the rates of change of drift speed and bow angle velocity.

[0011] A three-dimensional safety situation awareness system based on ship motion response is also provided, the system comprising: The ship motion state parameter calculation module is used to acquire ship data and environmental data, including data on distressed ships and rescue ships, and input them into the ship motion model to obtain the ship's motion state parameters. Specifically, the ship motion model obtains the real-time motion vector of the rescue ship through a four-degree-of-freedom nonlinear state-space equation and obtains the drift motion vector of the distressed ship through a drift state-space equation. The 3D safety situation awareness output module is used to input motion state parameters into a 3D dynamic ship domain model and output the final 3D safety situation awareness result through the coupled calculation of multi-dimensional hazard factors; among which, the multi-dimensional hazard factors include time collision hazard, spatial collision hazard, and roll collision hazard.

[0012] According to the above scheme, the three-dimensional security situation cognition result output module is specifically used to construct a three-dimensional dynamic ship domain model based on the three-dimensional ellipsoidal ship domain. The length of the horizontal semi-major axis of the three-dimensional ellipsoid is specifically calculated based on the fixed semi-major axis length, speed, and roll angle of the ship when it is stationary and without rolling. The length of the horizontal semi-minor axis of the three-dimensional ellipsoid is specifically calculated based on the fixed semi-minor axis length, speed, and roll angle of the ship when it is stationary and without rolling. The length of the vertical semi-axis of the three-dimensional ellipsoid is specifically calculated based on the ship's draft.

[0013] A computer storage medium is also provided, which stores a computer program that can be executed by a processor, the computer program executing the three-dimensional safety situation cognition method based on ship motion response described above.

[0014] The beneficial effects of this invention are as follows: This invention obtains the motion state parameters of distressed and rescue vessels based on the four-degree-of-freedom nonlinear state-space equation and the drift state-space equation, respectively, thereby achieving accurate analysis of the motion state of rescue and distressed vessels in three-dimensional space. Furthermore, by coupling multi-dimensional hazard factors to calculate the collision hazard, the collision hazard calculation incorporates time, space constraints, and roll effects, enabling precise quantification of collision risks during the rescue process and providing accuracy in risk assessment.

[0015] Furthermore, this invention constructs a three-dimensional dynamic ship domain model based on a three-dimensional ellipsoidal ship domain, extending the ship domain from a two-dimensional planar ellipse to a three-dimensional ellipsoid. It considers the influence of ship motion states such as speed and roll angle on the ship's safety boundary, and can more accurately describe the changes in the horizontal and vertical safety boundaries caused by speed and roll, thereby enhancing the accuracy of collision risk calculation and improving the accuracy of safety situation awareness results. Attached Figure Description

[0016] Figure 1 This is a flowchart illustrating the three-dimensional safety situation awareness method based on ship motion response according to an embodiment of the present invention. Figure 2 This is a schematic diagram of the coordinate system according to an embodiment of the present invention; Figure 3 This is a schematic diagram illustrating the calculation of the closest distance between two ships in the field of this invention. Figure 4 This is a schematic diagram of the hierarchical design framework of an embodiment of the present invention; Figure 5 This is a schematic diagram of the system structure of a three-dimensional safety situation awareness system based on ship motion response, according to an embodiment of the present invention. Detailed Implementation

[0017] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0018] Existing technologies suffer from insufficient understanding of ship safety situations. For example, existing two-dimensional ship safety situation assessment methods neglect three-dimensional motion responses such as roll and pitch, failing to accurately quantify collision risks in maritime emergency rescue scenarios, leading to biased collision risk assessments. Existing three-dimensional situation assessment models are mostly static geometric superpositions, unable to dynamically reflect the impact of ship motion on safety boundaries, and ill-suited for close-range interactions between rescue and distressed vessels. Furthermore, the lack of a three-dimensional safety situation assessment method based on ship motion responses fails to provide accurate collision risk quantification and situation characterization support for maritime emergency rescue. To address these shortcomings, this invention provides a three-dimensional safety situation assessment method based on ship motion responses, such as… Figure 1 As shown, the method includes: The system acquires ship data and environmental data, including data on distressed vessels and rescue vessels, and inputs them into the ship motion model to obtain the ship's motion state parameters. Specifically, the ship motion model obtains the real-time motion vector of the rescue vessel through a four-degree-of-freedom nonlinear state-space equation and obtains the drift motion vector of the distressed vessel through a drift state-space equation. The motion state parameters are input into a three-dimensional dynamic ship domain model, and the final three-dimensional safety situation perception result is output through the coupled calculation of multi-dimensional hazard factors; among which the multi-dimensional hazard factors include time collision hazard, spatial collision hazard and roll collision hazard.

[0019] First, this embodiment adopts the following... Figure 2 The coordinates shown are represented using the standard geodetic coordinate system OXYZ and the hull coordinate system oxyz in the field of marine engineering. The geodetic coordinate system OXYZ is an inertial coordinate system fixed to the Earth's surface, used to describe the ship's absolute position and attitude. The X, Y, and Z axes point to geographic north, east, and the Earth's center, respectively. The hull coordinate system oxyz is an appendage coordinate system with its origin located at the ship's center of gravity. It translates and rotates synchronously with the ship's motion and is used to describe the ship's velocity, angular velocity, and hydrodynamic forces / torques relative to the water. The X, Y, and Z axes point to the bow, starboard side, and keel, respectively.

[0020] Specifically, the four-degree-of-freedom nonlinear state-space equations in this embodiment are based on the three-degree-of-freedom Mathematical Modeling Group (MMG) model, with the addition of ship roll motion equations and consideration of coupling terms between degrees of freedom, to construct a four-degree-of-freedom MMG dynamic model, and then the equations are derived. The four-degree-of-freedom MMG dynamic model is specifically as follows:

[0021] In the formula: 'o' in all variable subscripts represents the rescue vessel. For ship quality; , The additional mass of the hull in the x-axis and y-axis directions; and These represent the ship's velocity and acceleration in the x-axis and y-axis directions, respectively. , For bow roll angular velocity and angular acceleration; For bow roll moment of inertia and additional moment of inertia; These are the roll angular velocity and angular acceleration. For the roll moment of inertia and the additional moment of inertia; and These represent the hydrodynamic forces acting on the hull along the x-axis, the control forces generated by the propeller and rudder, and the disturbance forces of wind and waves on the ship. and These represent the hydrodynamic forces acting on the hull along the y-axis, the control forces generated by the propeller and rudder, and the disturbance forces of wind and waves on the ship, respectively. and These represent the yaw moments about the z-axis generated by water, propeller, rudder, wind, and waves on the hull, respectively. and These represent the rolling moments about the x-axis exerted on the hull by the water, propeller, rudder, wind, and waves, respectively.

[0022] In addition, the location of the rescue ship in the geodetic coordinate system is defined as follows: The heading angle is The roll angle is Considering the effect of the roll on the projection of the sway velocity onto the horizontal plane, its kinematic relationship can be expressed as follows:

[0023] In the formula: , These are the rates of change of longitudinal and lateral displacement of the rescue vessel, and the rates of change of bow and roll angles, respectively.

[0024] Based on the above formula, the four-degree-of-freedom nonlinear state-space equation of the rescue vessel is derived. Specifically, the rate of change of the rescue vessel's motion state over time is calculated using the system matrix, control input matrix, disturbance input matrix, system state vector, control input vector, and environmental disturbance vector. Among them, the system state includes longitudinal and lateral velocities, yaw and roll angular velocities, x-axis and y-axis accelerations, bow angular acceleration, and roll angular acceleration. The control input vector specifically consists of the rudder angle and propeller speed of the rescue vessel.

[0025] Specifically, the four-degree-of-freedom nonlinear state-space equation can be expressed as follows:

[0026] In the formula: It is a vector-valued function used to describe the nonlinear changes between the state, control input, disturbance input, and state change rate of the four-degree-of-freedom maneuvering motion system of the rescue vessel; , , These are the control input vector, the environmental disturbance vector, and the output vector, respectively.

[0027] Specifically, its system state vector can be defined as:

[0028] in, It can be represented as: In the formula: , These are the rudder angle and the propeller speed, respectively.

[0029] It can be represented as: In the formula: This represents the wind and wave interference model, and its output is the equivalent force and torque generated by wind and waves on the ship hull.

[0030] It can be represented as: In the formula: For wind speed and wind direction; These are wave height, wavelength, and wave direction, respectively.

[0031] Unlike wind and waves, uniform currents do not act directly on the hull as independent external forces or torques. Instead, they affect the hydrodynamics and torques of the bare hull, rudder, and propeller by altering the relative motion between the hull and the surrounding water. The key to its modeling lies in understanding the input parameters of the ocean current (…). ) Calculate the relative speed between the ship and the water ( ).

[0032] In conclusion, It can be represented as follows:

[0033] Given an initial system state vector The control input and environmental disturbance input are used to numerically integrate the four-degree-of-freedom nonlinear state-space equations using the fourth-order Runge-Kutta method, which yields the eight motion state variables corresponding to the four degrees of freedom. value.

[0034] In this embodiment, the distressed vessel data specifically refers to the motion data of the distressed vessel in a completely out-of-control state. The drift state space equation is specifically calculated based on the ship system state matrix, input matrix, output matrix, distressed vessel state vector, and environmental disturbance input vector to calculate the output vector and the rate of change of the distressed vessel's motion state over time. The motion state of a distressed vessel includes its longitudinal velocity, lateral velocity, bow roll rate, roll rate, acceleration along the x-axis and y-axis, and bow turn acceleration. The distressed vessel's state vector includes the distressed vessel's roll angle, bow angle, longitudinal and lateral displacements in the geodetic coordinate system, and the distressed vessel's drift velocity and bow angular velocity along the x and y axes in the ship's coordinate system. The input vector includes the velocities of the flow, wind, and waves in the x and y directions.

[0035] Specifically, when a distressed vessel is completely out of control, all main and auxiliary engines fail, resulting in no propulsion or rudder effect. It is mainly affected by environmental forces and exhibits a drifting motion.

[0036] Specifically, the drift state-space equations are based on a four-degree-of-freedom MMG model to establish a four-degree-of-freedom drift motion model under completely runaway conditions, and are derived from the drift motion model; the four-degree-of-freedom drift motion model can be expressed as:

[0037] In the formula: 'd' in the variable subscript represents the distressed vessel; the physical meanings of the other parameters and symbols are the same as those for rescue vessels. The position of the distressed vessel in the geodetic coordinate system is defined as... The heading angle is The roll angle is Considering the effect of the roll on the projection of the sway velocity onto the horizontal plane, its kinematic relationship can be expressed as:

[0038] In the formula: , These are the rates of change of longitudinal and lateral displacement of the distressed vessel, and the rates of change of bow and roll angles, respectively.

[0039] Its drift state-space equation can then be expressed as:

[0040] In the formula: It is a vector-valued function used to describe the nonlinear changes between the state, disturbance input, and rate of change of the state of the distressed vessel's four-degree-of-freedom drift motion system. , These are the system environment disturbance input vector and output vector, respectively.

[0041] The system state vector can be specifically defined as follows:

[0042] in, It can be represented as: In the formula: This represents the wind and wave interference model, and its output is the equivalent force and torque generated by wind and waves on the ship hull.

[0043] in, It can be represented as: The impact of ocean currents on distressed vessels is also based on ocean current parameters ( ), calculate the relative speed between the ship and the water ( ).

[0044] In conclusion, It can be represented as follows:

[0045] Similarly, given the initial system state vector The control input and environmental disturbance input are used to numerically integrate the drift state space equations using the fourth-order Runge-Kutta method, which yields the eight motion state variables corresponding to the four degrees of freedom. value.

[0046] Furthermore, the ship's domain in existing technologies is typically defined as an area around the ship where other ships or obstacles should not enter. It can have shapes such as circular, elliptical, and fan-shaped. A two-dimensional elliptical ship domain can be represented in the ship's coordinate system as follows:

[0047] In the formula, a and b are the lengths of the semi-axis of the ellipse along the bow and starboard directions, which are determined by the ship's design parameters.

[0048] Transforming this field to a geodetic coordinate system, it can be represented as:

[0049] Two-dimensional static domain models assume the ship is always "upright," depicting safety boundaries only in the horizontal plane. Essentially, they are static projections of safety occupancy in three-dimensional space. While effective for calculating collision risks between the ship and other obstacles in a plane, in high-wave rescue operations, ship rolling causes the hull (and rescue equipment / contact interfaces) to tilt in space, changing the direction of safety occupancy. Therefore, they cannot accurately represent changes in horizontal and vertical safety boundaries caused by ship motion. This invention considers the influence of ship motion states such as speed and roll angle on the ship's safety boundaries, extending the ship domain from a planar ellipse to a three-dimensional ellipsoid. That is, using ship motion state variables as input and the ship domain radius as output, a three-dimensional dynamic ship domain model is constructed in the ship's coordinate system.

[0050] Specifically, the three-dimensional dynamic ship domain model is constructed based on a three-dimensional ellipsoidal ship domain. The length of the horizontal semi-major axis of the three-dimensional ellipsoid is calculated based on the fixed semi-major axis length, speed, and roll angle of a stationary ship without rolling. The length of the horizontal semi-minor axis of the three-dimensional ellipsoid is calculated based on the fixed semi-minor axis length, speed, and roll angle of a stationary ship without rolling. The length of the vertical semi-axis of the three-dimensional ellipsoid is calculated based on the ship's draft. This can be represented as follows:

[0051] In the formula: , , These are the radius lengths along the x-axis, y-axis, and z-axis directions in the ellipsoidal ship domain, respectively, and their dynamic changes are only related to motion state variables that have a direct impact on the safety boundary; , , These are the half-shaft lengths when the ship is stationary and not rolling (typically) > ); , For speed influence coefficient, , , This represents the roll effect coefficient. Specifically, the values ​​and calculations of the above parameters can be expressed as follows: Referring to the relationship between dimensions and length in classic shipbuilding models, and considering the characteristics of emergency rescue scenarios, this paper adopts... , , , These are the captain and draft, respectively. According to ship maneuverability theory, a ship's domain expands with increasing speed. For every 1 knot increase in speed, the long axis increases by 3.0% and the short axis increases by 1.0%, i.e. , ; Based on ship stability theory, rolling causes changes in the ship's hydrodynamic characteristics. It is assumed that for every 1 degree increase in the rolling angle, the length of the major, minor, and vertical axes increases by 1.5%, 3.0%, and 1.0%, respectively. , , .

[0052] Preferably, to calculate the spatial distance between the rescue area and the distressed vessel, the area is rotated to a geodetic coordinate system using real-time attitude angles, achieving synchronization between the area and the vessel's attitude, which can be expressed as:

[0053] In the formula: The displacement is in the vertical direction; since heave motion has not been considered, therefore... Substituting the above formula into the three-dimensional dynamic ship domain model, we can obtain the three-dimensional dynamic ship domain of the rescue vessel in the geodetic coordinate system:

[0054] Specifically, the results of the three-dimensional security situation awareness are obtained in the following ways: Calculate the distance between the nearest points on the surface of the three-dimensional ellipsoidal vessel domain for distressed and rescue vessels; The time hazard factor, spatial hazard factor, and roll hazard factor are calculated based on the distance to the nearest point on the surface. The collision hazard is then calculated by multiplying the time hazard factor, spatial hazard factor, and roll hazard factor together to obtain the final safety situation assessment result.

[0055] Among them, the surface nearest point distance in the three-dimensional ellipsoidal ship domain Specifically, the calculation is performed by subtracting the semi-axial projection of the two ellipsoids along the line connecting their centers from the distance between their centers. Figure 3 As shown, the specific calculation steps are as follows: Let the centers of the two ellipsoids be respectively The concentric vector is ; Calculate the unit direction vector ; For each ellipsoid, calculate its direction "Equivalent radius" , The calculation formula is as follows:

[0056] In the formula: , , and , , These are the lengths of the long, short, and vertical half-axis of the rescue vessel and the vessel in distress, respectively. , , Let be the components of the direction vector in the ship's coordinate system; then .

[0057] The spatial hazard factor, defined based on the monotonically negative correlation between distance and risk, can be expressed as:

[0058] In the formula, when At that time, the two domains are tangent or intersect. This indicates the highest risk of a space collision. When At that time, the risk of space collisions increases exponentially. Range variation, The smaller the value, the closer CRIS is to 1. When and When the exponential term approaches 0, This indicates that the risk of a space collision is the lowest. To represent a scale parameter, the average size of the two ellipsoids can be taken, and the calculation formula is as follows:

[0059] The time hazard factor, based on the monotonically negative correlation between time and hazard, and combined with the Time of Most Close Encounter (TCPA) definition, can be expressed as:

[0060]

[0061] in, , and , These represent the relative distance and speed along the X and Y axes, respectively. When TCPA ≥ 0, the two ships are approaching each other; the smaller the TCPA, the larger the CRIT, reflecting an increase in time urgency. When TCPA < 0, the two ships have passed their closest point and are moving away from each other; the larger |TCPA|, the smaller the CRIT, reflecting that the risk has gradually dissipated after the danger has passed. This is a time threshold, set to 600 seconds, when TCPA ≥ 0 and is much smaller than 0. When the exponent term approaches 0, CRIT 1. The time-sensitive risk level reaches its maximum; when TCPA... At that time, CRIT 0.37, which is at a moderate level, when TCPA is much greater than When the exponent term approaches negative infinity, CRIT 0, lowest risk in terms of time. The roll hazard factor, which considers the impact of roll on collision risk, is defined as follows:

[0062] In the formula, For reference purposes, this indicates that rescue operations will be significantly affected if the roll value is exceeded. Based on maritime rescue practice, 15° is used. This is the collision sensitivity coefficient, used to adjust the amplification of collision risk by roll. The physical meaning of this factor is: when any ship has a large roll angle, the ship's attitude is unstable, its collision avoidance ability decreases, and the collision risk increases; that is, under the same spatial distance and time urgency, the more violent the roll, the higher the final collision risk, reflecting the "amplification" effect of roll on risk.

[0063] Based on the above risk factors, the collision risk level can be expressed as: .

[0064] In summary, this embodiment adopts the following... Figure 4 The hierarchical design of the “ship motion modeling layer - safety situation cognition layer” shown revolves around the core logic of “motion state analysis - three-dimensional risk quantification”. The orderly transmission and deep coupling of data between layers are achieved through ship motion state variables, ensuring a closed-loop logic throughout the entire process from environmental disturbance input to safety situation output.

[0065] The ship motion modeling layer serves as the foundation of the entire framework. Using inherent ship parameters and environmental data such as wind, waves, and currents as input, it constructs motion models for rescue vessels and distressed vessels based on ship dynamics principles, ultimately analyzing the real-time motion states of both types of vessels. For rescue vessels with active maneuverability, a four-degree-of-freedom nonlinear state-space equation is constructed. By defining state vectors (characterizing dynamic information such as position, attitude, and velocity), control input vectors (active control quantities such as rudder angle and propeller speed), and disturbance input vectors (environmental disturbance forces / torques), key state variables such as position, attitude, and velocity are extracted after numerical solution using the fourth-order Runge-Kutta method. For distressed vessels that have lost control, the focus is on their drift motion characteristics, constructing a drift state-space equation to quantify the coupling effects of flow-induced drift, wind-induced drift, and wave drift, thereby accurately outputting the motion state parameters of the distressed vessel.

[0066] Furthermore, the safety situation awareness layer uses the motion state variables of the rescue vessel and the distressed vessel output from the ship motion modeling layer as input to complete the quantitative representation of the three-dimensional safety situation in stages. First, based on motion state parameters such as speed and roll angle, a three-dimensional dynamic ship domain model is constructed. By dynamically adjusting the ship domain radius, real-time adaptation to the ship's safety boundary is achieved. On this basis, a collision hazard assessment model integrating time collision hazard, spatial collision hazard, and roll collision hazard factors is established. Through the coupled calculation of multi-dimensional hazard factors, the collision risk of the two vessels in three-dimensional space is accurately quantified, and finally, a complete three-dimensional safety situation awareness result is output.

[0067] Furthermore, this embodiment of the invention also provides a three-dimensional safety situation awareness system based on ship motion response, used to implement the three-dimensional safety situation awareness method based on ship motion response described in this embodiment, such as... Figure 5 As shown, the system includes: The ship motion state parameter calculation module is used to acquire ship data and environmental data, including data on distressed ships and rescue ships, and input them into the ship motion model to obtain the ship's motion state parameters. Specifically, the ship motion model obtains the real-time motion vector of the rescue ship through a four-degree-of-freedom nonlinear state-space equation and obtains the drift motion vector of the distressed ship through a drift state-space equation. The 3D safety situation awareness output module is used to input motion state parameters into a 3D dynamic ship domain model and output the final 3D safety situation awareness result through the coupled calculation of multi-dimensional hazard factors; among which, the multi-dimensional hazard factors include time collision hazard, spatial collision hazard, and roll collision hazard.

[0068] The various modules or mechanisms of the system are mainly used to implement the various steps of the above method embodiments, and will not be described in detail here.

[0069] Finally, this embodiment of the invention also provides a computer storage medium storing a computer program that can be executed by a processor, the computer program executing the three-dimensional safety situation cognition method based on ship motion response described above.

[0070] This invention achieves accurate analysis of the motion state of the distressed and rescue vessels in three-dimensional space by obtaining the motion state parameters of the distressed and rescue vessels respectively based on the four-degree-of-freedom nonlinear state-space equation and the drift state-space equation. Furthermore, it calculates the collision risk by coupling multi-dimensional risk factors, which integrates time, space constraints, and roll effects, enabling precise quantification of collision risks during the rescue process and providing accuracy in risk assessment.

[0071] Furthermore, this embodiment of the invention constructs a three-dimensional dynamic ship domain model based on a three-dimensional ellipsoidal ship domain, extending the ship domain from a two-dimensional planar ellipse to a three-dimensional ellipsoid. It considers the influence of ship motion states such as speed and roll angle on the ship's safety boundary, and can more accurately describe the changes in the horizontal and vertical safety boundaries caused by speed and roll, thereby enhancing the accuracy of collision risk calculation and improving the accuracy of safety situation awareness results.

[0072] It should be noted that, depending on the implementation needs, the various steps / components described in this application can be broken down into more steps / components, or two or more steps / components or parts of the operation of steps / components can be combined into new steps / components to achieve the purpose of this invention.

[0073] The order of the steps in the above embodiments does not imply the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of this application.

[0074] It should be understood that those skilled in the art can make improvements or modifications based on the above description, and all such improvements and modifications should fall within the protection scope of the appended claims.

Claims

1. A three-dimensional safety situation awareness method based on ship motion response, characterized in that, The method includes: The system acquires ship data and environmental data, including data on distressed vessels and rescue vessels, and inputs them into the ship motion model to obtain the ship's motion state parameters. Specifically, the ship motion model obtains the real-time motion vector of the rescue vessel through a four-degree-of-freedom nonlinear state-space equation and obtains the drift motion vector of the distressed vessel through a drift state-space equation. The motion state parameters are input into a three-dimensional dynamic ship domain model, and the final three-dimensional safety situation perception result is output through the coupled calculation of multi-dimensional hazard factors; among which the multi-dimensional hazard factors include time collision hazard, spatial collision hazard and roll collision hazard.

2. The three-dimensional safety situation awareness method based on ship motion response according to claim 1, characterized in that, The distressed vessel data includes a distressed vessel state vector describing the vessel's position, attitude, speed, and angular velocity; the distressed vessel drift state space equation is specifically solved based on the distressed vessel data and environmental data to determine the rate of change of the distressed vessel's motion state over time.

3. The three-dimensional safety situation awareness method based on ship motion response according to claim 1, characterized in that, The three-dimensional dynamic ship domain model is specifically constructed based on the three-dimensional ellipsoidal ship domain. The length of the horizontal semi-major axis of the three-dimensional ellipsoid is specifically calculated based on the fixed semi-major axis length, speed, and roll angle of the ship when it is stationary and without rolling. The length of the horizontal semi-minor axis of the three-dimensional ellipsoid is specifically calculated based on the fixed semi-minor axis length, speed, and roll angle of the ship when it is stationary and without rolling. The length of the vertical semi-axis of the three-dimensional ellipsoid is specifically calculated based on the ship's draft.

4. The three-dimensional safety situation awareness method based on ship motion response according to claim 3, characterized in that, The results of the three-dimensional security situation awareness are obtained in the following ways: Calculate the distance between the nearest points on the surface of the three-dimensional ellipsoidal vessel domain for distressed and rescue vessels; The time hazard factor, spatial hazard factor, and roll hazard factor are calculated based on the distance to the nearest point on the surface. The collision hazard is then calculated by multiplying the time hazard factor, spatial hazard factor, and roll hazard factor together to obtain the final safety situation assessment result.

5. The three-dimensional safety situation awareness method based on ship motion response according to claim 1, characterized in that, The four-degree-of-freedom nonlinear state-space equations specifically calculate the rate of change of the rescue vessel's motion state over time using the system state vector, control input vector, and environmental disturbance vector. The system status includes longitudinal and lateral velocities, bow and roll angular velocities, x-axis and y-axis accelerations, bow angular accelerations, and roll angular accelerations; the control input vectors are specifically the rudder angle and propeller speed of the rescue vessel.

6. The three-dimensional safety situation awareness method based on ship motion response according to claim 1, characterized in that, The distressed vessel data specifically refers to the motion data of a distressed vessel in a completely out-of-control state. The drift state space equation is specifically calculated based on the distressed vessel's state vector and the environmental disturbance input vector to determine the output vector and the rate of change of the distressed vessel's motion state over time. The motion state of a distressed vessel includes its longitudinal velocity, lateral velocity, bow roll rate, roll rate, acceleration along the x-axis and y-axis, and bow turn acceleration. The distressed vessel's state vector includes the distressed vessel's roll angle, bow angle, longitudinal and lateral displacements in the geodetic coordinate system, and the distressed vessel's drift velocity and bow angular velocity along the x and y axes in the ship's coordinate system. The input vector includes the velocities of the flow, wind, and waves in the x and y directions.

7. The three-dimensional safety situation awareness method based on ship motion response according to claim 6, characterized in that, The rate of change of the motion state of a distressed vessel over time includes the rate of change of position, the rate of change of bow angle, the rate of change of roll angle, and the rates of change of drift speed and bow angular velocity.

8. A three-dimensional safety situation awareness system based on ship motion response, characterized in that, The system includes: The ship motion state parameter calculation module is used to acquire ship data and environmental data, including data on distressed ships and rescue ships, and input them into the ship motion model to obtain the ship's motion state parameters. Specifically, the ship motion model obtains the real-time motion vector of the rescue ship through a four-degree-of-freedom nonlinear state-space equation and obtains the drift motion vector of the distressed ship through a drift state-space equation. The 3D safety situation awareness output module is used to input motion state parameters into a 3D dynamic ship domain model and output the final 3D safety situation awareness result through the coupled calculation of multi-dimensional hazard factors; among which, the multi-dimensional hazard factors include time collision hazard, spatial collision hazard, and roll collision hazard.

9. The three-dimensional safety situation awareness system based on ship motion response according to claim 8, characterized in that, The 3D security situation awareness output module is specifically used to construct a 3D dynamic ship domain model based on a 3D ellipsoidal ship domain. Specifically, the length of the horizontal semi-major axis of the 3D ellipsoid is calculated based on the fixed semi-major axis length, speed, and roll angle of the ship when it is stationary and without rolling. The length of the horizontal semi-minor axis of the 3D ellipsoid is calculated based on the fixed semi-minor axis length, speed, and roll angle of the ship when it is stationary and without rolling. The length of the vertical semi-axis of the 3D ellipsoid is calculated based on the ship's draft.

10. A computer storage medium, characterized in that, It contains a computer program that can be executed by a processor, which performs the three-dimensional safety situation awareness method based on ship motion response as described in any one of claims 1-7.

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