Dredger path planning method and device, dredger and storage medium

Abstract

The invention discloses a dredger path planning method and device, a dredger and a storage medium. The method comprises the following steps of: decomposing the current second-order force, wind force, flow force and pulling force of the dredger to obtain each subitem load under an external coordinate system, and carrying out vector superposition on the subitem loads to obtain the current external total external load; performing equal-interval sampling in an optional range of the ship thrust component under the internal coordinate system according to a preset sampling interval to obtain each candidate ship thrust component; calculating each candidate navigational speed under the external coordinate system based on the current external total external load, the rotation matrix, the mass matrix, the Coriolis force matrix, the damping force matrix and each candidate ship thrust component; calculating a path point corresponding to each candidate navigational speed at each time point based on a preset time sequence and each candidate navigational speed, and connecting the path points corresponding to the same candidate navigational speed at each time point to obtain candidate paths; and calculating the driving cost of each candidate path, and determining the candidate path with the minimum driving cost as the target path of the dredger.

Description

Technical Field

[0001] The embodiments of the present invention relate to the technical field of dredgers, and in particular, to a path planning method, device, dredger, and storage medium for a dredger. Background Art

[0002] As a key equipment for dredging projects, trailing suction hopper dredgers are widely used in fields such as channel excavation, port construction, and water area dredging. During the actual operation process, the path planning of trailing suction hopper dredgers plays a decisive role in improving operation efficiency, ensuring navigation safety, and reducing operation costs.

[0003] Currently, the path planning of dredgers mostly depends on the personal experience of operators and their understanding of the operation area to complete. However, this method is greatly affected by the personal experience and subjective judgment of operators, lacking precise calculation and scientific basis. Once encountering a complex operation environment or a new operation area, it is difficult to guarantee the accuracy of the planned path.

[0004] Therefore, there is an urgent need to propose a new method to solve the above problems. Summary of the Invention

[0005] The present invention provides a path planning method, device, dredger, and storage medium for a dredger, effectively improving the accuracy and precision of path planning.

[0006] In a first aspect, the embodiments of the present invention provide a path planning method for a dredger, the method comprising:

[0007] Decompose the current second-order force, current wind force, current flow force, and current pulling force of the dredger in the external coordinate system item by item to obtain each item load of the dredger in the external coordinate system, and perform vector superposition operation on the each item load to obtain the current external total external load of the dredger in the external coordinate system;

[0008] Perform equidistant sampling within the optional range of the ship thrust component in the internal coordinate system according to a preset sampling interval to obtain each candidate ship thrust component;

[0009] Based on the current external total external load, rotation matrix, dredger mass matrix, dredger Coriolis force matrix, dredger damping force matrix, and the each candidate ship thrust component, calculate the speed corresponding to each candidate ship thrust component to obtain each candidate speed of the dredger in the external coordinate system;

[0010] Based on a preset time series and the each candidate speed, calculate the path points corresponding to each candidate speed at each time point, and connect the path points corresponding to the same candidate speed at each time point to obtain each candidate path of the dredger;

[0011] Calculate the travel costs of the candidate paths, and determine the candidate path with the minimum travel cost as the target path of the dredger.

[0012] In the technical solution of the present invention, first, the current second-order force, current wind force, current flow force, and current pulling force of the dredger in the external coordinate system are decomposed item by item to obtain the itemized loads of the dredger in the external coordinate system. Then, a vector superposition operation is performed on the itemized loads to obtain the current external total external load of the dredger in the external coordinate system, providing a data basis for obtaining the candidate speeds of the dredger in the external coordinate system. Then, equidistant sampling is performed within the optional range of the ship thrust component in the internal coordinate system according to a preset sampling interval to obtain each candidate ship thrust component, providing a data basis for obtaining the candidate speeds of the dredger in the external coordinate system. Next, based on the current external total external load, rotation matrix, dredger mass matrix, dredger Coriolis force matrix, dredger damping force matrix, and each candidate ship thrust component, the speeds corresponding to each candidate ship thrust component are calculated to obtain the candidate speeds of the dredger in the external coordinate system, comprehensively considering the influence of various factors (such as complex external forces like wind, waves, and currents) on the movement of the dredger, greatly improving the accuracy of determining the candidate speeds, and providing basic data for subsequent path planning. Then, based on a preset time series and each candidate speed, the path points corresponding to each candidate speed at each time point are calculated, and the path points corresponding to the same candidate speed at each time point are connected to obtain the candidate paths of the dredger, providing a data basis for determining the target path of the dredger. Finally, calculate the travel costs of the candidate paths, and determine the candidate path with the minimum travel cost as the target path of the dredger, significantly improving the accuracy of determining the target path, greatly enhancing the rationality of determining the target path, and effectively ensuring the operation efficiency of the dredger. Therefore, the technical solution of the present invention improves the accuracy of determining the candidate paths and the target path by improving the accuracy of determining the candidate speeds, effectively solving the problem that it is difficult to guarantee the path planning accuracy in the prior art.

[0013] In a second aspect, an embodiment of the present invention further provides a path planning device for a dredger, and the device includes:

[0014] A total external load determination module, configured to decompose the current second-order force, current wind force, current flow force, and current pulling force of the dredger in the external coordinate system item by item to obtain the itemized loads of the dredger in the external coordinate system, and perform a vector superposition operation on the itemized loads to obtain the current external total external load of the dredger in the external coordinate system;

[0015] A candidate thrust determination module, configured to perform equidistant sampling within the optional range of the ship thrust component in the internal coordinate system according to a preset sampling interval to obtain each candidate ship thrust component;

[0016] A candidate speed determination module, configured to calculate the speeds corresponding to the respective candidate ship thrust components based on the current external total external load, rotation matrix, dredger mass matrix, dredger Coriolis force matrix, dredger damping force matrix, and the respective candidate ship thrust components, so as to obtain the respective candidate speeds of the dredger in the external coordinate system;

[0017] A candidate path determination module, configured to calculate the path points corresponding to each candidate speed at each time point based on a preset time series and the respective candidate speeds, and connect the path points corresponding to the same candidate speed at each time point to obtain the respective candidate paths of the dredger;

[0018] A target path determination module, configured to calculate the travel costs of the respective candidate paths, and determine the candidate path with the minimum travel cost as the target path of the dredger.

[0019] In a third aspect, an embodiment of the present invention further provides a dredger, where the dredger includes:

[0020] At least one processor; and a memory communicatively connected to the at least one processor;

[0021] Wherein, the memory stores a computer program executable by the at least one processor, and the computer program is executed by the at least one processor so that the at least one processor can execute the path planning method of the dredger according to any one of the first aspects.

[0022] In a fourth aspect, an embodiment of the present invention further provides a storage medium containing computer-executable instructions, and the computer-executable instructions implement the path planning method of the dredger according to any one of the first aspects when executed by a computer processor.

[0023] It should be noted that the above computer instructions may be stored in whole or in part on a computer-readable storage medium. Among them, the computer-readable storage medium may be packaged together with the processor of the path planning device of the dredger, or may be separately packaged from the processor of the path planning device of the dredger. This application does not make any limitations in this regard.

[0024] The descriptions of the second aspect, the third aspect, and the fourth aspect in this application may refer to the detailed description of the first aspect; and, for the beneficial effects of the descriptions of the second aspect, the third aspect, and the fourth aspect, reference may be made to the analysis of the beneficial effects of the first aspect, and details are not repeated here.

[0025] In this application, the names of the above path planning devices of the dredger do not limit the devices or functional modules themselves. In actual implementation, these devices or functional modules may appear under other names. As long as the functions of each device or functional module are similar to those of this application and fall within the scope of the claims of this application and their equivalent technologies.

[0026] These aspects or other aspects of the present application will be more clearly understood in the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings required for the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0028] Figure 1 It is a flowchart of a path planning method for a dredger provided by an embodiment of the present invention;

[0029] Figure 2a It is a flowchart of another path planning method for a dredger provided by an embodiment of the present invention;

[0030] Figure 2b It is an example diagram of the safety boundary distance and the warning boundary distance provided by an embodiment of the present invention;

[0031] Figure 2c It is an example diagram of the safe navigation area provided by an embodiment of the present invention;

[0032] Figure 2d It is an example diagram of the navigation warning area provided by an embodiment of the present invention;

[0033] Figure 2e It is an example diagram of the course deviation angle of the candidate path provided by an embodiment of the present invention;

[0034] Figure 3 It is a schematic structural diagram of a path planning device for a dredger provided by an embodiment of the present invention;

[0035] Figure 4 It is a schematic structural diagram of a dredger provided by an embodiment of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0036] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It can be understood that the specific embodiments described herein are only used to explain the present invention, rather than limiting the present invention. Additionally, it should be noted that for the sake of description, only the parts related to the present invention are shown in the accompanying drawings rather than all the structures.

[0037] The term "and / or" in this article is only a description of the association relationship of associated objects, indicating that there can be three relationships. For example, A and / or B can represent: A exists alone, A and B exist simultaneously, and B exists alone.

[0038] In the description of the present application and the accompanying drawings, terms such as "first" and "second" are used to distinguish different objects or different processes for the same object, rather than to describe a specific order of the objects.

[0039] In addition, the terms "include" and "have" and any variations thereof mentioned in the description of the present application are intended to cover non-exclusive inclusion. For example, a process, method, system, product or device that includes a series of steps or units is not limited to the listed steps or units, but optionally further includes other steps or units not listed, or optionally further includes other steps or units inherent to these processes, methods, products or devices.

[0040] Before discussing the exemplary embodiments in more detail, it should be mentioned that some exemplary embodiments are described as processes or methods depicted as flowcharts. Although the flowcharts describe the operations (or steps) as sequential processes, many of the operations can be implemented in parallel, concurrently or simultaneously. In addition, the order of the operations can be rearranged. The process can be terminated when its operations are completed, but can also have additional steps not included in the drawings. The process can correspond to a method, function, procedure, subroutine, subprogram, etc. In addition, without conflict, the embodiments in the present invention and the features in the embodiments can be combined with each other.

[0041] It should be noted that in the embodiments of the present application, words such as "exemplary" or "for example" are used to represent examples, illustrations or explanations. Any embodiment or design solution described as "exemplary" or "for example" in the embodiments of the present application should not be construed as being more preferred or having more advantages than other embodiments or design solutions. Rather, the use of words such as "exemplary" or "for example" is intended to present the relevant concepts in a specific manner.

[0042] In the description of the present application, unless otherwise specified, the meaning of "a plurality of" refers to two or more.

[0043] Figure 1 It is a flowchart of a path planning method for a dredger provided for an embodiment of the present invention. This embodiment is applicable to situations where path planning for a dredger is required. This method can be executed by a path planning device of the dredger, and the device can be implemented in software and / or hardware. Exemplarily, the device can be integrated in the dredger. Refer to Figure 1 , the path planning method for the dredger in this embodiment specifically includes the following steps:

[0044] Step 110: Decompose the current second-order force, current wind force, current current force, and current pulling force of the dredger in the external coordinate system item by item to obtain the respective itemized loads of the dredger in the external coordinate system, and perform vector superposition operations on the respective itemized loads to obtain the current total external load of the dredger in the external coordinate system.

[0045] Specifically, a dredger refers to an engineering ship used for excavating underwater soil, sand, and other materials. For example, the dredger includes a trailing suction hopper dredger. The external coordinate system refers to a reference coordinate system fixed outside the hull, used to describe the position, attitude, and force conditions of the dredger relative to the surrounding environment, usually based on the earth's surface or a certain fixed geographical reference point. For example, the external coordinate system can be a north-east-earth coordinate system established with the geometric center point of the dredger operation area or the initial operation starting point of the dredger as the origin. The second-order force refers to the non-linear hydrodynamic load received by the dredger in a wave environment. The wind force refers to the aerodynamic load acting on the hull and superstructure of the dredger. The current force refers to the hydrodynamic load generated by the water flow on the underwater part of the dredger (hull, drag arm, etc.). The pulling force refers to the traction force generated by the interaction between the drag head of the dredger and the seabed. The itemized load refers to the individual independent load components obtained by decomposing the various forces (such as second-order force, wind force, current force, pulling force, etc.) received by the dredger in the external coordinate system respectively. The current total external load refers to the resultant force of all external loads obtained by the dredger in the external coordinate system after itemized decomposition and vector superposition operations.

[0046] In specific implementation, the current second-order force, current wind force, current current force, and current pulling force of the dredger in the external coordinate system can be obtained first according to the anemometer, marine meteorological station, ship state observer, and drag head pulling force sensor, and then the obtained forces are decomposed according to the axis directions of the external coordinate system to obtain the respective itemized loads of the dredger in the external coordinate system. After that, the components in the same direction after decomposition are superimposed to obtain the current total external load.

[0047] In this embodiment, through the above steps, a data basis is provided for obtaining the respective candidate ship speeds of the dredger in the external coordinate system later.

[0048] Step 120: Perform equally spaced sampling within the optional range of the ship thrust component in the internal coordinate system according to the preset sampling interval to obtain the respective candidate ship thrust components.

[0049] Specifically, the preset sampling interval refers to the numerical interval between two adjacent candidate ship thrust components preset according to the actual situation or requirements. The internal coordinate system refers to the coordinate system established with the dredger itself as the reference. For example: The internal coordinate system can have the center of gravity of the dredger as the origin, the x-axis along the length direction of the dredger, with the bow as the positive direction; the y-axis perpendicular to the length direction of the dredger, with the right as the positive direction; and the z-axis perpendicular to the hull plane, with the upward direction as the positive direction. The internal coordinate system and the external coordinate system can be converted through a rotation matrix. The ship thrust component refers to each component of the thrust generated by the dredger propulsion system (i.e., the ship thrust) in the internal coordinate system. Since the movement of the dredger has multiple degrees of freedom, the thrust can be decomposed into components in different directions, such as longitudinal thrust components, lateral thrust components, and vertical thrust components, etc. In this embodiment, the ship thrust component refers to the vertical thrust component, and the optional range refers to the range of possible values of the ship thrust component in the internal coordinate system. The candidate ship thrust component refers to each possible value of the ship thrust component obtained during the equidistant sampling process.

[0050] Exemplarily, if in the z-axis direction of the internal coordinate system of the dredger, the optional range of the ship thrust component is [10, 50], with the unit of kilonewton (kN), and the preset sampling interval is 5 kN, then the candidate ship thrust components include 10 kN, 15 kN, 20 kN, 25 kN, 30 kN, 35 kN, 40 kN, 45 kN, and 50 kN.

[0051] In this embodiment, through the above steps, a data basis is provided for subsequently obtaining each candidate speed of the dredger in the external coordinate system.

[0052] Step 130: Based on the current external total external load, rotation matrix, dredger mass matrix, dredger Coriolis force matrix, dredger damping force matrix, and each candidate ship thrust component, calculate the speed corresponding to each candidate ship thrust component to obtain each candidate speed of the dredger in the external coordinate system.

[0053] Specifically, the rotation matrix refers to the matrix that transforms a vector in the internal coordinate system to the external coordinate system. For example: The rotation matrix can be , where ψ is the heading angle of the dredger. The dredger mass matrix refers to the matrix that describes the mass characteristics of the dredger. For example: The dredger mass matrix can be , where m(d) is the change in the dredger mass with the dredger draft depth d, and I Z (d) is the change in the rotational variable about the vertical axis with the dredger draft depth d. The dredger Coriolis force matrix refers to the matrix related to the rotational motion of the dredger. For example: The dredger Coriolis force matrix can be , where \(u\) is the velocity of the dredger along the longitudinal direction (x-axis direction) in the internal coordinate system, \(m\) is the mass of the dredger, and \(v\) is the internal speed of the dredger in the internal coordinate system. The dredger damping force matrix refers to the matrix that describes the damping force characteristics of the dredger when moving in water. For example, the dredger damping force matrix can be , \(X(d)\) is the longitudinal damping force coefficient, \(Y(d)\) is the lateral damping force coefficient, and \(N(d)\) is the yaw damping force coefficient. Each candidate speed refers to the speed value of the dredger in the external coordinate system calculated corresponding to each candidate ship thrust component.

[0054] In the specific implementation, first, based on the current external total external load, rotation matrix, dredger mass matrix, dredger Coriolis force matrix, dredger damping force matrix, and candidate ship thrust, the motion equation of the dredger is constructed (such as \(n = Rv\), \(Mv'+Cv + Dv=\tau+R -1 w. Where \(n\) is the candidate speed of the dredger in the external coordinate system, \(M\) is the dredger mass matrix, \(C\) is the dredger Coriolis force matrix, \(D\) is the dredger damping force matrix, \(\tau\) is the candidate ship thrust, \(R\) is the rotation matrix, \(w\) is the current external total external load, \(v\) is the internal speed of the dredger in the internal coordinate system, and \(v'\) is the first derivative of \(v\)). Then, based on the constructed motion equation, the speeds corresponding to each candidate ship thrust component are calculated to obtain the candidate speeds of the dredger in the external coordinate system. Specifically, for the current candidate ship thrust component, first, based on the current candidate ship thrust component, the current candidate ship thrust of the dredger in the internal coordinate system is determined, and then the product of the inverse matrix of the rotation matrix and the current external total external load is calculated to obtain the current internal total external load of the dredger in the internal coordinate system; the sum of the current internal total external load and the current candidate ship thrust is calculated to obtain the current combined thrust; based on the current combined thrust, dredger mass matrix, dredger Coriolis force matrix, and dredger damping force matrix, the current internal speed of the dredger in the internal coordinate system is calculated; according to the rotation matrix and the current internal speed, the speed corresponding to the current candidate ship thrust component is calculated to obtain the candidate speed of the dredger in the external coordinate system.

[0055] In this embodiment, through the above steps, various factors (such as complex external forces like wind, waves, and currents) affecting the motion of the dredger are comprehensively considered, greatly improving the accuracy of determining the candidate speeds and providing basic data for subsequent path planning.

[0056] Step 140: Based on the preset time series and each candidate speed, calculate the path points corresponding to each candidate speed at each time point, and connect the path points corresponding to the same candidate speed at each time point to obtain each candidate path of the dredger.

[0057] Specifically, the preset time series refers to a sequence of time points preset according to the actual situation or requirements. The path point refers to the position of the dredger at each time point calculated according to the candidate speed under the preset time series. The candidate path refers to the possible travel path of the dredger formed by connecting the path points corresponding to the same candidate speed at each time point.

[0058] In a specific implementation, for the current candidate speed, the current time and each time point in the preset time series are used to perform a time integration operation on the current candidate speed to obtain the displacement increment vector corresponding to each time point.

[0059] Adding the current position of the dredger to the displacement increment vectors corresponding to each time point, the path points corresponding to the current candidate speed at each time point are obtained.

[0060] In addition, in practical applications, the fourth-order Runge-Kutta method can also be used to process the preset time series and each candidate speed to obtain the path points corresponding to each candidate speed at each time point.

[0061] In this embodiment, through the above steps, a data basis is provided for determining the target path of the dredger later.

[0062] Step 150, calculate the travel costs of each candidate path, and determine the candidate path with the minimum travel cost as the target path of the dredger.

[0063] Specifically, the travel cost refers to a comprehensive index for measuring the costs such as resources, time, and energy consumed by the dredger when traveling along a certain candidate path. The target path refers to the path with the minimum travel cost selected from all candidate paths.

[0064] In a specific implementation, for the current candidate path, first calculate the risk degree of the obstacle corresponding to each path point in the current candidate path to obtain the obstacle risk value of each path point. The specific steps are as follows: calculate the spatial collision risk degree of each path point according to the safety boundary distance, warning boundary distance and closest encounter distance of the obstacle corresponding to each path point; calculate the time collision risk degree of each path point based on the slowest steering time, latest steering time and closest encounter time of the obstacle corresponding to each path point; perform non-linear fusion on the spatial collision risk degree of each path point and the time collision risk degree of each path point to obtain the obstacle risk value of each path point. Then sum the obstacle risk values of each path point to obtain the comprehensive risk degree of the current candidate path. At the same time, determine the path point corresponding to the time point with the largest timestamp in the preset time series as the path end point, and then calculate the course deviation angle of the current candidate path based on the path end point and the target navigation point; then perform weighted summation on the course deviation angle of the current candidate path and the comprehensive risk degree of the current candidate path to obtain the driving cost of the current candidate path. Finally, among all candidate paths, determine the path with the minimum driving cost as the target path of the dredger.

[0065] In this embodiment, through the above steps, the accuracy of target path determination is significantly improved, the rationality of target path determination is greatly enhanced, and the operation efficiency of the dredger is effectively guaranteed.

[0066] The path planning method for a dredger provided in an embodiment of the present invention first decomposes the current second-order force, current wind force, current flow force and current pulling force of the dredger in the external coordinate system into sub-items to obtain the sub-item loads of the dredger in the external coordinate system, and performs vector superposition operation on each sub-item load to obtain the current external total external load of the dredger in the external coordinate system, which provides a data basis for obtaining each candidate speed of the dredger in the external coordinate system. Then, sampling is performed at equal intervals within the optional range of the ship thrust component in the internal coordinate system according to a preset sampling interval to obtain each candidate ship thrust component, which provides a data basis for obtaining each candidate speed of the dredger in the external coordinate system. Then, based on the current total external load, rotation matrix, dredger mass matrix, dredger Coriolis force matrix, dredger damping force matrix and thrust components of each candidate ship, the speed corresponding to the thrust component of each candidate ship is calculated, and the candidate speeds of the dredger in the external coordinate system are obtained. The influence of various factors (such as wind, waves, currents and other complex external forces) on the movement of the dredger is fully considered, which greatly improves the accuracy of the candidate speed determination and provides basic data for subsequent path planning. Then, based on the preset time series and each candidate speed, the path points corresponding to each candidate speed at each time point are calculated, and the path points corresponding to the same candidate speed at each time point are connected to obtain the candidate paths of the dredger, which provides a data basis for determining the target path of the dredger later. Finally, the travel cost of each candidate path is calculated, and the candidate path with the smallest travel cost is determined as the target path of the dredger, which significantly improves the accuracy of the target path determination, greatly enhances the rationality of the target path determination, and effectively guarantees the operating efficiency of the dredger. Therefore, the technical solution of the present invention improves the accuracy of determining candidate speeds, thereby improving the accuracy of determining candidate paths and target paths, and effectively solves the problem of difficulty in ensuring path planning accuracy in the prior art.

[0067] Figure 2a A flowchart of another path planning method for a dredger provided in an embodiment of the present invention, which is specific based on the above embodiment. In this embodiment, the method may also include:

[0068] Step 210, decompose the current second-order force, current wind force, current flow force and current tension of the dredger in the external coordinate system into sub-items to obtain the sub-item loads of the dredger in the external coordinate system, perform vector superposition operation on the sub-item loads to obtain the current external total external load of the dredger in the external coordinate system.

[0069] Step 211: Perform equal-interval sampling within the optional range of the ship thrust component in the internal coordinate system according to a preset sampling interval to obtain candidate ship thrust components.

[0070] Further, before step 211, it further includes: determining a first optional set of the ship thrust component based on the maximum ship thrust component and the minimum ship thrust component of the dredger; calculating the product of the data sampling period of the dredger and the maximum change amplitude of the ship thrust component to obtain a moment change amount; calculating the difference between the current ship thrust component of the dredger and the moment change amount to obtain a ship thrust lower limit adjustment value, and calculating the sum of the maximum ship thrust component and the moment change amount to obtain a ship thrust upper limit adjustment value; determining a second optional set of the ship thrust component based on the ship thrust lower limit adjustment value and the ship thrust upper limit adjustment value; and determining the intersection of the first optional set and the second optional set as the optional range.

[0071] Specifically, the maximum ship thrust component refers to the maximum thrust value that the propulsion system of the dredger can provide in the vertical direction (Z-axis). The minimum ship thrust component refers to the minimum thrust value that the propulsion system of the dredger can provide in the vertical direction (Z-axis). The first optional set refers to a set of value ranges determined according to the maximum ship thrust component and the minimum ship thrust component of the dredger. This set contains all possible ship thrust component values and is a range defined based on the thrust capacity of the dredger itself. The data sampling period refers to the time interval for sampling the relevant data of the dredger determined in advance according to the actual situation or requirements. The maximum change amplitude refers to the maximum change amount that the ship thrust component can undergo per unit time. The second optional set refers to a set of value ranges of the ship thrust component determined based on the ship thrust lower limit adjustment value and the ship thrust upper limit adjustment value, and is a range defined based on the ship thrust change situation.

[0072] Exemplarily, if the maximum ship thrust component of the dredger is τzmax, the minimum ship thrust component is τzmin, the data sampling period of the dredger is , the maximum change amplitude of the ship thrust component is , and the current ship thrust component is τzc, then the first optional set of the ship thrust component is , the moment change amount is ; the ship thrust lower limit adjustment value is , the ship thrust upper limit adjustment value is ; the second optional set is ; the optional range is .

[0073] In this embodiment, through the above steps, the first optional set is first determined based on the maximum and minimum ship thrust components of the dredger, taking into account the capacity limitations of the equipment itself, and providing a basic feasible range for the ship thrust components. Then, the torque change amount is obtained by calculating the product of the data sampling period and the maximum change amplitude of the ship thrust components, and based on this, the lower limit adjustment value and the upper limit adjustment value of the ship thrust are obtained, and then the second optional set is determined, taking into account the rationality of the change of the ship thrust in the time series and avoiding too drastic changes in the thrust. Finally, the intersection of the two sets is taken as the optional range, comprehensively considering various factors such as equipment capacity and the smoothness of thrust change, improving the accuracy and rationality of the determination of the optional range.

[0074] Step 212: Based on the current external total external load, rotation matrix, dredger mass matrix, dredger Coriolis force matrix, dredger damping force matrix, and each candidate ship thrust component, calculate the speed corresponding to each candidate ship thrust component to obtain each candidate speed of the dredger in the external coordinate system.

[0075] Further, step 212 may specifically include: for the current candidate ship thrust component, determine the current candidate ship thrust of the dredger in the internal coordinate system based on the current candidate ship thrust component; calculate the product of the inverse matrix of the rotation matrix and the current external total external load to obtain the current internal total external load of the dredger in the internal coordinate system; calculate the sum of the current internal total external load and the current candidate ship thrust to obtain the current combined thrust; based on the current combined thrust, dredger mass matrix, dredger Coriolis force matrix, and dredger damping force matrix, calculate the current internal speed of the dredger in the internal coordinate system; according to the rotation matrix and the current internal speed, calculate the speed corresponding to the current candidate ship thrust component to obtain the candidate speed of the dredger in the external coordinate system.

[0076] Specifically, the current internal total external load refers to the total external load in the internal coordinate system obtained by multiplying the inverse matrix of the rotation matrix by the current external total external load, which represents the comprehensive effect of various external forces acting on the dredger in the internal coordinate system with the dredger itself as the reference. The current internal speed refers to the candidate speed of the dredger in the internal coordinate system calculated based on the current combined thrust, dredger mass matrix, dredger Coriolis force matrix, and dredger damping force matrix.

[0077] In specific implementation, for the current candidate ship thrust component, the current candidate ship thrust of the dredger in the internal coordinate system can be first determined based on the current candidate ship thrust component. For example, if the current candidate ship thrust component is τz, the current candidate ship thrust is τ = [τx, 0, τz], where τx is a constant representing the component of the ship thrust in the transverse direction. Then, calculate the product of the inverse matrix of the rotation matrix and the current external total external load to obtain the current internal total external load of the dredger in the internal coordinate system. Next, calculate the sum of the current internal total external load and the current candidate ship thrust to obtain the current combined thrust. Then, substitute the current combined thrust, the dredger mass matrix, the dredger Coriolis force matrix, and the dredger damping force matrix into the pre-established three-degree-of-freedom nonlinear motion equation of the dredger (such as Mv'+Cv+Dv=F, where M is the dredger mass matrix, C is the dredger Coriolis force matrix, D is the dredger damping force matrix, v is the internal speed of the dredger in the internal coordinate system, v' is the first derivative of v, and F is the current combined thrust) for solution to obtain the current internal speed of the dredger in the internal coordinate system. Finally, calculate the product of the rotation matrix and the current internal speed to obtain the candidate speed of the dredger in the external coordinate system.

[0078] In this embodiment, through the above steps, the accuracy and precision of the determined candidate speed are improved.

[0079] Step 213: Based on the preset time series and each candidate speed, calculate the path points corresponding to each candidate speed at each time point, and connect the path points corresponding to the same candidate speed at each time point to obtain each candidate path of the dredger.

[0080] Furthermore, based on the preset time series and each candidate speed, calculating the path points corresponding to each candidate speed at each time point includes: for the current candidate speed, performing a time integration operation on the current candidate speed using the current time and each time point in the preset time series to obtain the displacement increment vectors corresponding to each time point; adding the current position of the dredger to the displacement increment vectors corresponding to each time point to obtain the path points corresponding to the current candidate speed at each time point.

[0081] Specifically, the displacement increment vector refers to the vector obtained through the time integration operation, which represents the displacement change of the dredger relative to the current position at each time point, including the magnitude and direction of the displacement.

[0082] In specific implementation, for the current candidate speed, performing a time integration operation on the current candidate speed using the current time and each time point in the preset time series to obtain the displacement increment vectors corresponding to each time point; adding the current position of the dredger to the displacement increment vectors corresponding to each time point to obtain the path points corresponding to the current candidate speed at each time point.

[0083] Exemplarily, if the current candidate sailing speed is n = [u, p, r], where u represents the longitudinal speed of the dredger in the external coordinate system, p represents the lateral speed of the dredger in the external coordinate system, and r represents the yaw angular velocity of the dredger in the external coordinate system, the current time is t0, the preset time series includes time points t1 and t2, and the path point corresponding to the current candidate sailing speed at time point t0 is s0 = [x0, y0, ψ0], where (x0, y0) represents the position of the dredger in the external coordinate system at t0, and ψ0 represents the heading of the dredger in the external coordinate system at t0, then the displacement increment vector at time point t1 is , and the displacement increment vector at time point t2 is , and the path point corresponding to the current candidate sailing speed at time point t1 is , and the path point corresponding to the current candidate sailing speed at time point t2 is .

[0084] In this embodiment, through the above steps, the accuracy of the determined path points is improved.

[0085] Step 214: For the current candidate path, calculate the risk degree of the obstacles corresponding to each path point in the current candidate path to obtain the obstacle risk value of each path point, and sum the obstacle risk values of each path point to obtain the comprehensive risk degree of the current candidate path.

[0086] Specifically, the obstacles refer to the objects that may pose a threat to the safety of the dredger during its sailing path, such as other ships, reefs, shoals, etc. The obstacle risk value refers to the value used to quantify the risk degree of the path point. The comprehensive risk degree refers to the value used to quantify the risk degree of the candidate path.

[0087] In specific implementation, for the current candidate path, the spatial collision risk degree of each path point can be calculated according to the safety boundary distance, warning boundary distance, and closest encounter distance of the obstacles corresponding to each path point; based on the slowest steering time, latest steering time, and closest encounter time of the obstacles corresponding to each path point, calculate the time collision risk degree of each path point; weight the spatial collision risk degree of each path point and the time collision risk degree of each path point to obtain the obstacle risk value of each path point. Finally, sum the obstacle risk values of each path point to obtain the comprehensive risk degree of the current candidate path.

[0088] In this embodiment, through the above steps, a data basis is provided for calculating the driving cost of the current candidate path in the subsequent stage.

[0089] Further, calculate the risk degree of the obstacles corresponding to each path point in the current candidate path to obtain the obstacle risk value of each path point, including: for the current path point, calculate the spatial collision risk degree of the current path point according to the safety boundary distance, warning boundary distance, and closest encounter distance of the obstacle corresponding to the current path point; based on the slowest steering time, latest steering time, and closest encounter time of the obstacle corresponding to the current path point, calculate the time collision risk degree of the current path point; perform non-linear fusion on the spatial collision risk degree and the time collision risk degree of the current path point to obtain the obstacle risk value of the current path point.

[0090] Specifically, the safety boundary distance of the obstacle refers to the straight-line distance between the current position of the dredger during navigation and the intersection point of the straight line connecting the current position and the closest encounter point of the obstacle with the boundary of the safe navigation area (select the intersection point closest to the closest encounter point). The warning boundary distance of the obstacle refers to the straight-line distance between the current position of the dredger during navigation and the intersection point of the straight line connecting the current position and the closest encounter point of the obstacle with the boundary of the navigation warning area (select the intersection point closest to the closest encounter point) to the current position of the dredger (such as the current position of the geometric center of the dredger). The closest encounter point refers to the spatial point with the smallest relative distance on the movement trajectories of the dredger and the obstacle under the condition of maintaining the current motion state. Exemplarily, as Figure 2b shown, the gray polygon represents the dredger, the black dot represents the closest encounter point, the inner elliptical area is the safe navigation area, the outer elliptical area is the navigation warning area, D1 is the safety boundary distance, and D2 is the warning boundary distance. The safe navigation area refers to the water area range that should be maintained for safe passage by the dredger during navigation determined in advance according to the actual situation or requirements. For example: as Figure 2cAs shown, the gray polygon represents the dredger. L is the corrected length of the dredger, and its calculation formula is L = L0×(d / dmin). Among them, L0 is the actual length of the dredger; d is the real-time average draft of the dredger, that is, the average depth at which the hull of the dredger is immersed in water at the current moment during navigation; dmin is the average draft of the dredger in light load condition, that is, the average depth at which the hull of the dredger is immersed in water in the light load state (such as when there is no cargo, equipment or only a small amount of necessary items on the ship). The safe navigation area is an elliptical area. The major semi-axis of this ellipse is a, and its length is 5 times that of L; the minor semi-axis of this ellipse is b, and its length is 2.5 times that of L; Δa is the increment of the major semi-axis, and its length is 1.1 times that of L, that is, the additional length on the basis of the major semi-axis is 1.1 times that of L; Δb is the increment of the minor semi-axis, and its length is 0.75 times that of L, that is, the additional length on the basis of the minor semi-axis is 0.75 times that of L; the length of the major axis of this ellipse is 10 times that of L, and the length of the minor axis of this ellipse is 5 times that of L. The navigation warning area refers to a warning area delimited in advance according to the actual situation or needs to ensure the safe operation of the dredger. For example: as Figure 2d As shown, the gray polygon represents the dredger. L is the corrected length of the dredger, and its calculation formula is L = L0×(d / dmin). Among them, L0 is the actual length of the dredger; d is the real-time average draft of the dredger. The inner elliptical area is the safe navigation area, and its parameter information is the same as that of the safe navigation area in Figure 2c . The outer elliptical area is the navigation warning area. The length of the major axis of the outer ellipse is 10 times that of Lα, and the length of the minor axis of the outer ellipse is 5 times that of Lβ. Among them, α and β are parameters set in advance according to the actual situation or needs for determining the navigation warning area. The closest point of approach of the obstacle refers to the minimum spatial interval that the dredger is expected to reach in the future relative movement trajectory when navigating and the obstacle (such as other ships, buoys, reefs, etc.). The spatial collision risk degree of the obstacle refers to an index used to quantify the possibility of the dredger colliding with the obstacles in the operation area during operation or navigation. The slowest steering time refers to the time theoretically required for the dredger to travel from the current position to the position where the mildest steering method can be adopted to avoid collision. The latest steering time refers to the theoretical time required for the dredger to travel from the current position to the position where it must steer to avoid collision. The closest time of approach refers to the time required for the dredger and the obstacle to reach the closest point of approach under the condition of maintaining the current course and speed. The time collision risk degree refers to a numerical value for quantitatively evaluating the possibility of the dredger and the obstacle colliding in the time dimension.

[0091] In specific implementation, the obstacle corresponding to the current path point is identified from the target obstacle list of the current path point. Then, relevant information about the obstacle corresponding to the current path point (such as position information, safe boundary distance, warning boundary distance, closest distance of approach, closest time of approach, closest point of approach, angle of the closest point of approach relative to the dredger, etc.) is obtained through detection devices installed on the dredger (such as automatic identification systems, vision enhancement systems, marine radars, electronic nautical charts, lasers, etc.). Then, according to the safe boundary distance, warning boundary distance, and closest distance of approach of the obstacle corresponding to the current path point, the spatial collision risk degree of the obstacle corresponding to the current path point is calculated. Specifically, for the current obstacle, when the closest distance of approach of the current obstacle is less than the safe boundary distance of the current obstacle, the spatial collision risk degree of the current obstacle can be determined as a preset first spatial risk degree (such as 1, 0.99, 0.98, etc.). When the closest distance of approach of the current obstacle is not less than the safe boundary distance of the current obstacle and not greater than the warning boundary distance of the current obstacle, it is determined that the spatial collision risk degree of the current obstacle = , where DCPA is the closest distance of approach of the current obstacle, D1 is the safe boundary distance of the current obstacle, and D2 is the warning boundary distance of the current obstacle; when the closest distance of approach of the current obstacle is greater than the warning boundary distance of the current obstacle, the spatial collision risk degree of the current obstacle can be determined as a preset second spatial risk degree (such as 0, 0.01, 0.1, etc.). Then, the spatial collision risk degrees of the obstacles corresponding to the current path point are summed to obtain the spatial collision risk degree of the current path point.

[0092] Next, based on the gentlest steering time, latest steering time, and closest encounter time of the obstacle corresponding to the current waypoint, calculate the time collision risk degree of the current waypoint. Specifically, for the current obstacle, first calculate the square difference between the latest steering distance and the closest encounter distance of the current obstacle to obtain the first intermediate distance; perform a square root operation on the first intermediate distance to obtain the first target distance; calculate the ratio of the first target distance to the relative speed of the current obstacle to the dredger to obtain the latest steering time of the dredger and the current obstacle; calculate the square difference between the gentlest steering distance and the closest encounter distance of the current obstacle to obtain the second intermediate distance; perform a square root operation on the second intermediate distance to obtain the second target distance; calculate the ratio of the second target distance to the relative speed of the current obstacle to the dredger to obtain the gentlest steering time of the dredger and the current obstacle. Then, when the closest encounter time of the dredger and the current obstacle is less than the latest steering time of the dredger and the current obstacle, determine that the time collision risk degree of the current obstacle is a preset first time risk degree (such as 1, 0.9, 0.98, etc.); when the closest encounter time of the dredger and the current obstacle is not less than the latest steering time of the dredger and the current obstacle and not greater than the gentlest steering time of the dredger and the current obstacle, determine that the time collision risk degree of the current obstacle = , TCPA is the closest encounter time of the current obstacle, t3 is the latest steering time of the current obstacle, and t4 is the gentlest steering time of the current obstacle. When the closest encounter time of the current obstacle is greater than the gentlest steering time of the current obstacle, determine that the time collision risk degree of the current obstacle is a preset second time risk degree (such as 0, 0.01, 0.1, etc.). Then sum up the time collision risk degrees of the obstacles corresponding to the current waypoint to obtain the time collision risk degree of the current waypoint. Among them, the gentlest steering distance refers to the critical distance between the steering operation position and the obstacle when the dredger safely avoids the obstacle by adopting the gentlest steering method according to the actual situation or requirements. For example, the gentlest steering distance can be 12 nautical miles. The latest steering distance refers to the critical distance between the latest steering operation position where the dredger can safely avoid the obstacle and the obstacle determined according to the longitudinal moment of the ship and the adjustment parameter. For example: the latest steering distance = adjustment parameter × longitudinal moment of the ship, where the adjustment parameter is greater than one, and the longitudinal moment of the ship refers to the straight-line distance between the original position and the current position after the dredger rotates 180 degrees. The gentlest steering distance is greater than the latest steering distance.

[0093] Finally, perform non-linear fusion on the spatial collision risk degree and the time collision risk degree of the current waypoint to obtain the obstacle risk value of the current waypoint. Exemplarily, if the time collision risk degree of the current waypoint is TCR and the spatial collision risk degree of the current waypoint is DCR, then the obstacle risk value of the current waypoint is , where is the risk coupling coefficient, which refers to the coefficient used to balance the contribution ratio of the spatial collision risk and the temporal collision risk set according to the actual situation or requirements, and the range is between 0 and 1.

[0094] Optionally, for the current path point, the spatial risk of the obstacle corresponding to the current path point can be calculated based on the safety boundary distance, warning boundary distance, and closest encounter distance of the obstacle corresponding to the current path point; the temporal risk of the obstacle corresponding to the current path point can be calculated based on the slowest steering time, latest steering time, and closest encounter time of the obstacle corresponding to the current path point; the spatial risk and temporal risk of the obstacle corresponding to the current path point are non-linearly fused to obtain the target risk value of the obstacle corresponding to the current path point, and finally, the target risk values of the obstacles corresponding to the current path point are summed to obtain the obstacle risk value of the current path point.

[0095] It should be noted that the target obstacle list can be determined in advance according to the actual situation or requirements, or can be generated according to the real-time obstacle information detected by the detection equipment of the dredger. The embodiments of the present invention do not limit this.

[0096] In this embodiment, through the above steps, the risk is calculated from the spatial dimension and the temporal dimension respectively, avoiding the one-sidedness of evaluating the collision risk from only a single angle, comprehensively covering the spatial position relationship between the dredger and the obstacle and the dynamic evolution relationship in time, being able to more accurately reflect the actual collision risk situation, effectively evaluating the obstacle risk, improving the accuracy of the subsequent determined driving cost, thereby helping the dredger to more reasonably plan the navigation path, avoid high-risk areas, reduce the probability of collision accidents, and ensure the safe and smooth progress of the operation.

[0097] Step 215: Determine the path end point as the path point corresponding to the time point with the largest time stamp in the preset time series.

[0098] Specifically, the path end point refers to the path point corresponding to the time point with the largest time stamp in the preset time series.

[0099] Step 216: Calculate the vector pointing from the path end point to the target navigation point based on the path end point and the target navigation point to obtain the target pointing vector.

[0100] Specifically, the target navigation point refers to the target position point that the dredger expects to reach determined in advance according to the actual situation or requirements. The target pointing vector refers to the vector pointing from the path end point to the target navigation point.

[0101] Exemplarily, if the path end point is [3, 4, π / 4] and the target navigation point is [7, 9, π / 4], then the target pointing vector is [4, 5]. It should be noted that when calculating the target pointing vector, the effect of the heading angle in the vector calculation is not considered, and the position coordinate difference is mainly calculated.

[0102] In this embodiment, through the above steps, a data basis is provided for obtaining the heading deviation angle of the current candidate path subsequently.

[0103] Step 217: Based on the heading vector corresponding to the path end point and the target pointing vector, calculate the angle between the heading vector and the target pointing vector to obtain the heading deviation angle of the current candidate path.

[0104] Specifically, the heading vector refers to the vector corresponding to the heading of the dredger at the path end point. The heading deviation angle refers to the angle between the heading vector and the target pointing vector. For example: as Figure 2e shown, the gray pentagon represents the dredger, the three black dots are all path points, the lines formed by connecting the dredger with each path point are a candidate path, the black dot farthest from the dredger is the path end point, the gray triangle is the target navigation point, the ray pointing from the path end point to the target navigation point is the target pointing vector, the ray along the extension direction of the candidate path starting from the path end point is the heading vector, and θ is the heading deviation angle.

[0105] Exemplarily, if the path end point is [3, 4, π / 4] and the target pointing vector is [4, 5], then the heading vector is [3, 4], and the heading deviation angle is arccos[4 / (41) 1 / 2 .

[0106] In this embodiment, through the above steps, the accuracy of the subsequent calculated driving cost is improved.

[0107] Step 218: Perform a weighted sum of the heading deviation angle of the current candidate path and the comprehensive risk degree of the current candidate path to obtain the driving cost of the current candidate path.

[0108] In specific implementation, the driving cost of the current candidate path = deviation weight × the heading deviation angle of the current candidate path + risk degree weight × the comprehensive risk degree of the current candidate path. Among them, the deviation weight and the risk degree weight are set in advance according to the actual situation or requirements.

[0109] In one embodiment, after obtaining the course deviation angle and the comprehensive risk degree of each candidate path, the course deviation angles of each candidate path can be summed to obtain the total course deviation angle. Then, the course deviation angle of each candidate path is divided by the total course deviation angle respectively to complete the normalization of the course deviation angle, and the updated course deviation angles of each candidate path are obtained. Similarly, the comprehensive risk degrees of each candidate path are summed to obtain the total comprehensive risk degree. Subsequently, the comprehensive risk degree of each candidate path is divided by the total comprehensive risk degree respectively to realize the normalization of the comprehensive risk degree, and the updated comprehensive risk degrees of each candidate path are obtained. Finally, the weighted sum of the updated course deviation angles and comprehensive risk degrees of each candidate path is calculated to obtain the driving cost of each candidate path.

[0110] In this embodiment, through the above steps, the accuracy of the determined driving cost is improved.

[0111] Step 219: Determine the candidate path with the minimum driving cost as the target path of the dredger.

[0112] The path planning method for a dredger provided by an embodiment of the present invention first performs itemized decomposition on the current second-order force, current wind force, current flow force, and current pulling force of the dredger in an external coordinate system to obtain the itemized loads of the dredger in the external coordinate system, and performs vector superposition operations on the itemized loads to obtain the current external total external load of the dredger in the external coordinate system, providing a data basis for obtaining the candidate speeds of the dredger in the external coordinate system later. Then, equidistant sampling is performed within the selectable range of the ship thrust component in the internal coordinate system according to a preset sampling interval to obtain each candidate ship thrust component, providing a data basis for obtaining the candidate speeds of the dredger in the external coordinate system later. Next, based on the current external total external load, rotation matrix, dredger mass matrix, dredger Coriolis force matrix, dredger damping force matrix, and each candidate ship thrust component, the speeds corresponding to each candidate ship thrust component are calculated to obtain the candidate speeds of the dredger in the external coordinate system, comprehensively considering the influence of various factors (such as complex external forces like wind, waves, and currents) on the movement of the dredger, greatly improving the accuracy of determining the candidate speeds, and providing basic data for subsequent path planning. Then, based on a preset time series and each candidate speed, the path points corresponding to each candidate speed at each time point are calculated, and the path points corresponding to the same candidate speed at each time point are connected to obtain the candidate paths of the dredger, providing a data basis for determining the target path of the dredger later. After that, for the current candidate path, the risk degree of the obstacle corresponding to each path point in the current candidate path is calculated to obtain the obstacle risk value of each path point, and the sum of the obstacle risk values of each path point is obtained as the comprehensive risk degree of the current candidate path, providing a data basis for calculating the driving cost of the current candidate path later. The path point corresponding to the time point with the largest timestamp in the preset time series is determined as the path end point. Based on the path end point and the target navigation point, the vector pointing from the path end point to the target navigation point is calculated to obtain the target pointing vector. Based on the heading vector corresponding to the path end point and the target pointing vector, the included angle between the heading vector and the target pointing vector is calculated to obtain the heading deviation angle of the current candidate path, improving the accuracy of the driving cost calculated later. The weighted sum of the heading deviation angle of the current candidate path and the comprehensive risk degree of the current candidate path is obtained as the driving cost of the current candidate path, realizing the determination of the driving cost from two key dimensions of heading deviation and collision risk, effectively improving the accuracy of determining the driving cost, and further enhancing the rationality of the finally determined target path. Finally, the candidate path with the minimum driving cost is determined as the target path of the dredger, effectively ensuring the navigation safety and operation efficiency of the dredger. Therefore, the technical solution of the present invention improves the accuracy of determining the target path by enhancing the accuracy of determining the candidate speeds and driving costs, effectively solving the problem that it is difficult to guarantee the path planning accuracy in the prior art.

[0113] Figure 3The structural schematic diagram of a path planning device for a dredger provided by an embodiment of the present invention. This device and the path planning method of the dredger in the above embodiments belong to the same inventive concept. For the details not described in detail in the embodiment of the path planning device of the dredger, reference can be made to the embodiment of the path planning method of the dredger above.

[0114] As Figure 3 shown, the device includes:

[0115] A total external load determination module 310, configured to perform component decomposition on the current second-order force, current wind force, current flow force, and current pulling force of the dredger in the external coordinate system to obtain each component load of the dredger in the external coordinate system, and perform vector superposition operation on the each component load to obtain the current external total load of the dredger in the external coordinate system;

[0116] A candidate thrust determination module 320, configured to perform equidistant sampling within the optional range of the ship thrust component in the internal coordinate system according to a preset sampling interval to obtain each candidate ship thrust component;

[0117] A candidate speed determination module 330, configured to calculate the speed corresponding to each candidate ship thrust component based on the current external total load, rotation matrix, dredger mass matrix, dredger Coriolis force matrix, dredger damping force matrix, and the each candidate ship thrust component to obtain each candidate speed of the dredger in the external coordinate system;

[0118] A candidate path determination module 340, configured to calculate the path points corresponding to each candidate speed at each time point based on a preset time series and the each candidate speed, and connect the path points corresponding to the same candidate speed at each time point to obtain each candidate path of the dredger;

[0119] A target path determination module 350, configured to calculate the driving cost of the each candidate path and determine the candidate path with the minimum driving cost as the target path of the dredger.

[0120] Based on the above embodiments, the device further includes:

[0121] An optional range determination module, configured to determine a first optional set of ship thrust components based on the maximum ship thrust component and the minimum ship thrust component of the dredger before equally spaced sampling within the optional range of the ship thrust components in the internal coordinate system according to a preset sampling interval to obtain each candidate ship thrust component; calculate the product of the data sampling period of the dredger and the maximum change amplitude of the ship thrust component to obtain a moment change amount; calculate the difference between the current ship thrust component of the dredger and the moment change amount to obtain a ship thrust lower limit adjustment value, and calculate the sum of the maximum ship thrust component and the moment change amount to obtain a ship thrust upper limit adjustment value; determine a second optional set of ship thrust components based on the ship thrust lower limit adjustment value and the ship thrust upper limit adjustment value; and determine the intersection of the first optional set and the second optional set as the optional range.

[0122] Based on the above embodiments, the candidate speed determination module 330 is specifically configured to:

[0123] For the current candidate ship thrust component, determine the current candidate ship thrust of the dredger in the internal coordinate system based on the current candidate ship thrust component;

[0124] Calculate the product of the inverse matrix of the rotation matrix and the current external total external load to obtain the current internal total external load of the dredger in the internal coordinate system;

[0125] Calculate the sum of the current internal total external load and the current candidate ship thrust to obtain the current comprehensive thrust;

[0126] Based on the current comprehensive thrust, the dredger mass matrix, the dredger Coriolis force matrix, and the dredger damping force matrix, calculate the current internal speed of the dredger in the internal coordinate system;

[0127] According to the rotation matrix and the current internal speed, calculate the speed corresponding to the current candidate ship thrust component to obtain the candidate speed of the dredger in the external coordinate system.

[0128] Based on the above embodiments, the candidate path determination module 340 calculates the path points corresponding to each candidate speed at each time point based on a preset time series and the candidate speeds, including:

[0129] For the current candidate speed, perform a time integration operation on the current candidate speed using the current time and each time point in the preset time series to obtain a displacement increment vector corresponding to each time point;

[0130] Add the current position of the dredger to the displacement increment vector corresponding to each time point to obtain the path points corresponding to the current candidate speed at each time point.

[0131] Based on the above embodiments, the target path determination module 350 calculates the driving costs of the candidate paths, including:

[0132] For the current candidate path, calculate the risk levels of the obstacles corresponding to each path point in the current candidate path to obtain the obstacle risk values of each path point, and sum the obstacle risk values of each path point to obtain the comprehensive risk level of the current candidate path;

[0133] Determine the path point corresponding to the time point with the largest time stamp in the preset time series as the path end point, and calculate the course deviation angle of the current candidate path based on the path end point and the target navigation point;

[0134] Perform a weighted sum of the course deviation angle of the current candidate path and the comprehensive risk level of the current candidate path to obtain the driving cost of the current candidate path.

[0135] Based on the above embodiments, the target path determination module 350 calculates the risk levels of the obstacles corresponding to each path point in the current candidate path to obtain the obstacle risk values of each path point, including:

[0136] For the current path point, calculate the spatial collision risk level of the current path point according to the safety boundary distance, warning boundary distance, and closest encounter distance of the obstacle corresponding to the current path point;

[0137] Based on the slowest steering time, latest steering time, and closest encounter time of the obstacle corresponding to the current path point, calculate the time collision risk level of the current path point;

[0138] Perform a non-linear fusion of the spatial collision risk level and the time collision risk level of the current path point to obtain the obstacle risk value of the current path point.

[0139] Based on the above embodiments, the target path determination module 350 calculates the course deviation angle of the current candidate path based on the path end point and the target navigation point, including:

[0140] Based on the path end point and the target navigation point, calculate the vector pointing from the path end point to the target navigation point to obtain the target pointing vector;

[0141] Based on the course vector corresponding to the path end point and the target pointing vector, calculate the angle between the course vector and the target pointing vector to obtain the course deviation angle of the current candidate path.

[0142] The path planning device of the dredger provided by the embodiments of the present invention can execute the path planning method of the dredger provided by any embodiment of the present invention, and has the corresponding functional modules and beneficial effects for executing the method.

[0143] It should be noted that in the embodiments of the path planning device of the above dredger, the various units and modules included are only divided according to functional logic, but are not limited to the above division, as long as the corresponding functions can be realized; in addition, the specific names of the functional units are only for the convenience of mutual distinction and do not limit the protection scope of the present invention.

[0144] Figure 4 FIG. 5 is a schematic structural diagram of a dredger provided by an embodiment of the present invention. Figure 4 FIG. 6 shows a block diagram of an exemplary dredger 4 suitable for use in implementing an embodiment of the present invention. Figure 4 The dredger 4 shown is merely an example and should not impose any limitation on the functions and usage scope of the embodiments of the present invention.

[0145] As Figure 4 shown, the dredger 4 is presented in the form of a general-purpose computing electronic device. The components of the dredger 4 may include, but are not limited to: one or more processors or processing units 16, a system memory 28, and a bus 18 connecting different system components (including the system memory 28 and the processing unit 16).

[0146] The bus 18 represents one or more of several types of bus structures, including a memory bus or memory controller, a peripheral bus, a graphics acceleration port, a processor, or a local bus using any of the multiple bus structures. By way of example, these architectures include, but are not limited to, Industry Standard Architecture (ISA) bus, Micro Channel Architecture (MAC) bus, Enhanced ISA bus, Video Electronics Standards Association (VESA) local bus, and Peripheral Component Interconnect (PCI) bus.

[0147] The dredger 4 typically includes a variety of computer system-readable media. These media can be any available media accessible by the dredger 4, including volatile and non-volatile media, removable and non-removable media.

[0148] The system memory 28 may include computer system-readable media in the form of volatile memory, such as RAM 30 and / or cache 32. The dredger 4 may further include other removable / non-removable, volatile / non-volatile computer system storage media. By way of example only, the storage system 34 may be used for reading and writing non-removable, non-volatile magnetic media ( Figure 4 not shown, typically referred to as a "hard disk drive"). Although Figure 4Not shown in the figure, a disk drive for reading and writing a removable non-volatile disk (such as a "floppy disk") and an optical disk drive for reading and writing a removable non-volatile optical disk (such as a CD-ROM, DVD-ROM or other optical medium) can be provided. In these cases, each drive can be connected to the bus 18 through one or more data medium interfaces. The system memory 28 may include at least one program product having a set (such as at least one) of program modules configured to perform the functions of the embodiments of the present invention.

[0149] A program / utility 40 having a set (at least one) of program modules 42 can be stored, for example, in the system memory 28. Such program modules 42 include, but are not limited to, an operating system, one or more application programs, other program modules, and program data. Each or some combination of these examples may include the implementation of a network environment. The program modules 42 generally perform the functions and / or methods in the embodiments described in the present invention.

[0150] The dredger 4 can also communicate with one or more external devices 14 (such as a keyboard, a pointing device, a display 24, etc.), and can also communicate with one or more devices that enable a user to interact with the dredger 4, and / or communicate with any device that enables the dredger 4 to communicate with one or more other computing devices (such as a network card, a modem, etc.). Such communication can be carried out through the I / O interface 22. Moreover, the dredger 4 can also communicate with one or more networks (such as a local area network (LAN), a wide area network (WAN) and / or a public network, such as the Internet) through the network adapter 20. As Figure 4 shown, the network adapter 20 communicates with other modules of the dredger 4 through the bus 18. It should be understood that although Figure 4 not shown in the figure, other hardware and / or software modules can be used in combination with the dredger 4, including but not limited to: microcode, device drivers, redundant processing units, external disk drive arrays, RAID systems, tape drives, and data backup storage systems, etc.

[0151] The processing unit 16 executes various functional applications and page displays by running the programs stored in the system memory 28, for example, implementing the path planning method of the dredger provided by the embodiments of the present invention. The method includes:

[0152] Performing sub-item decomposition on the current second-order force, current wind force, current flow force, and current pulling force of the dredger in the external coordinate system to obtain the sub-item loads of the dredger in the external coordinate system, and performing vector superposition operation on the sub-item loads to obtain the current external total external load of the dredger in the external coordinate system;

[0153] Perform equidistant sampling within the optional range of the ship thrust components in the internal coordinate system according to a preset sampling interval to obtain each candidate ship thrust component;

[0154] Based on the current external total external load, rotation matrix, dredger mass matrix, dredger Coriolis force matrix, dredger damping force matrix, and each candidate ship thrust component, calculate the speed corresponding to each candidate ship thrust component to obtain each candidate speed of the dredger in the external coordinate system;

[0155] Based on a preset time series and each candidate speed, calculate the path points corresponding to each candidate speed at each time point, and connect the path points corresponding to the same candidate speed at each time point to obtain each candidate path of the dredger;

[0156] Calculate the travel cost of each candidate path, and determine the candidate path with the minimum travel cost as the target path of the dredger.

[0157] Of course, those skilled in the art can understand that the processor can also implement the technical solutions of the path planning method of the dredger provided in any embodiment of the present invention.

[0158] An embodiment of the present invention provides a computer-readable storage medium, on which a computer program is stored. When the program is executed by a processor, it implements, for example, the path planning method of the dredger provided in the embodiment of the present invention. The method includes:

[0159] Perform itemized decomposition on the current second-order force, current wind force, current flow force, and current pulling force of the dredger in the external coordinate system to obtain each itemized load of the dredger in the external coordinate system, and perform vector superposition operation on each itemized load to obtain the current external total external load of the dredger in the external coordinate system;

[0160] Perform equidistant sampling within the optional range of the ship thrust components in the internal coordinate system according to a preset sampling interval to obtain each candidate ship thrust component;

[0161] Based on the current external total external load, rotation matrix, dredger mass matrix, dredger Coriolis force matrix, dredger damping force matrix, and each candidate ship thrust component, calculate the speed corresponding to each candidate ship thrust component to obtain each candidate speed of the dredger in the external coordinate system;

[0162] Based on a preset time series and each candidate speed, calculate the path points corresponding to each candidate speed at each time point, and connect the path points corresponding to the same candidate speed at each time point to obtain each candidate path of the dredger;

[0163] Calculate the travel cost of each candidate path, and determine the candidate path with the minimum travel cost as the target path of the dredger.

[0164] The computer storage medium of the embodiments of the present invention may adopt any combination of one or more computer-readable media. The computer-readable medium may be a computer-readable signal medium or a computer-readable storage medium. The computer-readable storage medium may be, for example, but not limited to, an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any combination of the above. More specific examples (non-exhaustive list) of the computer-readable storage medium include: an electrical connection having one or more wires, a portable computer disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the above. In this document, the computer-readable storage medium may be any tangible medium that contains or stores a program that can be used by or in conjunction with an instruction execution system, apparatus, or device.

[0165] The computer-readable signal medium may include a data signal propagated in a baseband or as part of a carrier wave, which carries the computer-readable program code. Such a propagated data signal may take various forms, including but not limited to electromagnetic signals, optical signals, or any suitable combination of the above. The computer-readable signal medium may also be any computer-readable medium other than the computer-readable storage medium, which can send, propagate, or transmit a program for use by or in conjunction with an instruction execution system, apparatus, or device.

[0166] The program code contained on the computer-readable medium may be transmitted using any appropriate medium, including but not limited to: wireless, wire, optical fiber cable, RF, etc., or any suitable combination of the above.

[0167] The computer program code for performing the operations of the present invention may be written in one or more programming languages or combinations thereof. The programming languages include object-oriented programming languages such as Java, Smalltalk, C++, and also include conventional procedural programming languages such as the "C" language or similar programming languages. The program code may be executed entirely on the user's computer, partially on the user's computer, executed as a stand-alone software package, partially on the user's computer and partially on a remote computer, or entirely on a remote computer or server. In the case of a remote computer, the remote computer may be connected to the user's computer through any type of network, including a local area network (LAN) or a wide area network (WAN), or may be connected to an external computer (e.g., by using an Internet service provider to connect through the Internet).

[0168] Those of ordinary skill in the art should understand that the various modules or steps of the present invention described above can be implemented using a general-purpose computing device. They can be concentrated on a single computing device or distributed across a network composed of multiple computing devices. Optionally, they can be implemented using program code executable by a computer device, so that they can be stored in a storage device and executed by the computing device, or they can be separately fabricated into individual integrated circuit modules, or multiple modules or steps among them can be fabricated into a single integrated circuit module for implementation. Thus, the present invention is not limited to any specific combination of hardware and software.

[0169] In addition, in the technical solution of the present invention, the acquisition, storage, use, processing, etc. of data all comply with the relevant provisions of laws and regulations.

[0170] Note that the above is only the preferred embodiment of the present invention and the technical principles applied. Those skilled in the art will understand that the present invention is not limited to the specific embodiments here. Various obvious changes, re-adjustments, and substitutions can be made by those skilled in the art without departing from the protection scope of the present invention. Therefore, although the present invention has been described in more detail through the above embodiments, the present invention is not limited to the above embodiments. Without departing from the concept of the present invention, it can also include more other equivalent embodiments, and the scope of the present invention is determined by the scope of the appended claims.

Claims

1. A path planning method for a dredger, characterized in that: include: The current second-order force, current wind force, current flow force and current pulling force of the dredger in the external coordinate system are decomposed into sub-items to obtain the sub-item loads of the dredger in the external coordinate system, and the vector superposition operation is performed on the sub-item loads to obtain the current external total external load of the dredger in the external coordinate system; Based on the maximum ship thrust component and the minimum ship thrust component of the dredger, a first optional set of ship thrust components is determined; the product of the data sampling period of the dredger and the maximum change amplitude of the ship thrust component is calculated to obtain the torque change; the difference between the current ship thrust component of the dredger and the torque change is calculated to obtain the ship thrust lower limit adjustment value, and the sum of the maximum ship thrust component and the torque change is calculated to obtain the ship thrust upper limit adjustment value; based on the ship thrust lower limit adjustment value and the ship thrust upper limit adjustment value, a second optional set of ship thrust components is determined; the intersection of the first optional set and the second optional set is determined as the optional range of the ship thrust component; Performing equal-interval sampling within an optional range of the ship thrust component in the internal coordinate system according to a preset sampling interval to obtain each candidate ship thrust component; Based on the current external total external load, the rotation matrix, the dredger mass matrix, the dredger Coriolis force matrix, the dredger damping force matrix and the thrust components of the candidate ships, the speed corresponding to the thrust components of the candidate ships is calculated to obtain the candidate speeds of the dredger in the external coordinate system; Based on the preset time series and the candidate speeds, the path points corresponding to each candidate speed at each time point are calculated, and the path points corresponding to the same candidate speed at each time point are connected to obtain the candidate paths of the dredger; The travel costs of the candidate paths are calculated, and the candidate path with the minimum travel cost is determined as the target path of the dredger.

2. The path planning method for a dredger according to claim 1, characterized in that: Based on the current total external load, the rotation matrix, the dredger mass matrix, the dredger Coriolis force matrix, the dredger damping force matrix and the thrust components of the candidate ships, the speed corresponding to the thrust components of the candidate ships is calculated to obtain the candidate speeds of the dredger in the external coordinate system, including: For the current candidate ship thrust component, determining the current candidate ship thrust of the dredger in the internal coordinate system based on the current candidate ship thrust component; Calculate the product of the inverse matrix of the rotation matrix and the current total external load to obtain the current total internal external load of the dredger in the internal coordinate system; Calculating the sum of the current total internal external load and the current candidate ship thrust to obtain the current comprehensive thrust; Calculating the current internal speed of the dredger in the internal coordinate system based on the current comprehensive thrust, the dredger mass matrix, the dredger Coriolis force matrix and the dredger damping force matrix; The speed corresponding to the thrust component of the current candidate ship is calculated according to the rotation matrix and the current internal speed, so as to obtain the candidate speed of the dredger in the external coordinate system.

3. The path planning method for a dredger according to claim 1, characterized in that: Based on the preset time series and the candidate speeds, the path point corresponding to each candidate speed at each time point is calculated, including: For the current candidate speed, use the current time and each time point in the preset time sequence to perform a time integration operation on the current candidate speed to obtain a displacement increment vector corresponding to each time point; The current position of the dredger is added with the displacement increment vector corresponding to each time point to obtain the path point corresponding to the current candidate speed at each time point.

4. The path planning method for a dredger according to claim 1, characterized in that: Calculating the travel cost of each candidate path includes: For the current candidate path, calculate the danger level of the obstacle corresponding to each path point in the current candidate path, obtain the obstacle danger value of each path point, and sum up the obstacle danger values ​​of each path point to obtain the comprehensive danger level of the current candidate path; Determine the path point corresponding to the time point with the largest timestamp in the preset time sequence as the path end point, and calculate the heading deviation angle of the current candidate path based on the path end point and the target navigation point; The heading deviation angle of the current candidate path and the comprehensive risk level of the current candidate path are weightedly summed to obtain the travel cost of the current candidate path.

5. The path planning method for a dredger according to claim 4, characterized in that: Calculate the danger level of the obstacle corresponding to each path point in the current candidate path, and obtain the obstacle danger value of each path point, including: For the current path point, the spatial collision risk of the current path point is calculated according to the safety boundary distance, warning boundary distance and closest encounter distance of the obstacle corresponding to the current path point; Calculating the time collision risk of the current path point based on the slowest steering time, the latest steering time and the closest encounter time of the obstacle corresponding to the current path point; The spatial collision risk of the current path point and the temporal collision risk of the current path point are nonlinearly fused to obtain the obstacle risk value of the current path point.

6. The path planning method for a dredger according to claim 4, characterized in that: Based on the path endpoint and the target navigation point, calculating the heading deviation angle of the current candidate path includes: Based on the path endpoint and the target navigation point, a vector pointing from the path endpoint to the target navigation point is calculated to obtain a target pointing vector; Based on the heading vector corresponding to the path endpoint and the target pointing vector, an angle between the heading vector and the target pointing vector is calculated to obtain a heading deviation angle of the current candidate path.

7. A path planning device for a dredger, characterized in that: include: The total external load determination module is used to decompose the current second-order force, current wind force, current flow force and current tension of the dredger in the external coordinate system, obtain the sub-item loads of the dredger in the external coordinate system, and perform vector superposition operation on the sub-item loads to obtain the current external total external load of the dredger in the external coordinate system; An optional range determination module is used to perform equal-interval sampling within an optional range of the ship thrust component in the internal coordinate system according to a preset sampling interval, and determine a first optional set of ship thrust components based on the maximum ship thrust component and the minimum ship thrust component of the dredger before obtaining each candidate ship thrust component; calculate the product of the data sampling period of the dredger and the maximum change amplitude of the ship thrust component to obtain a torque change; calculate the difference between the current ship thrust component of the dredger and the torque change to obtain a ship thrust lower limit adjustment value, and calculate the sum of the maximum ship thrust component and the torque change to obtain a ship thrust upper limit adjustment value; determine a second optional set of ship thrust components based on the ship thrust lower limit adjustment value and the ship thrust upper limit adjustment value; determine the intersection of the first optional set and the second optional set as the optional range of the ship thrust component; A candidate thrust determination module is used to perform equal-interval sampling within an optional range of the ship thrust component in the internal coordinate system according to a preset sampling interval to obtain each candidate ship thrust component; A candidate speed determination module is used to calculate the speed corresponding to the thrust component of each candidate ship based on the current external total external load, the rotation matrix, the dredger mass matrix, the dredger Coriolis force matrix, the dredger damping force matrix and the thrust components of each candidate ship, so as to obtain each candidate speed of the dredger in the external coordinate system; A candidate path determination module is used to calculate the path points corresponding to each candidate speed at each time point based on a preset time sequence and the candidate speeds, and connect the path points corresponding to the same candidate speed at each time point to obtain candidate paths for the dredger; The target path determination module is used to calculate the travel costs of the candidate paths and determine the candidate path with the minimum travel cost as the target path of the dredger.

8. A dredging vessel, characterized in that: The dredger comprises: at least one processor; and a memory communicatively coupled to the at least one processor; Wherein, the memory stores a computer program executable by the at least one processor, and the computer program is executed by the at least one processor so that the at least one processor can execute the path planning method for a dredger as described in any one of claims 1-6.

9. A storage medium containing computer executable instructions, characterized in that: The computer executable instructions are used to execute the path planning method for a dredging vessel as described in any one of claims 1-6 when executed by a computer processor.

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