Four-degree-of-freedom dual-ho path planning method, system, device and medium

Abstract

The application provides a four-degree-of-freedom double-sling path planning method, system, device and medium, the method comprising: analyzing the degree-of-freedom system of a double-Crane according to kinematics, and constructing a four-degree-of-freedom model of the double-Crane; obtaining hoisting task information, determining a target task and a target path type; calculating the motion parameters of a target path based on the kinematics of the four-degree-of-freedom model, generating a simplest target path and a shortest target path according to the motion parameters; and determining an optimal path in the target path according to span constraints and collision constraints.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of heavy lift ship, in particular to a four-degree-of-freedom double-crane path planning method, system, device and medium. BACKGROUND

[0002] When the heavy lift ship carries oversized, special and heavy goods, the double-crane linkage is needed to complete the loading and unloading of the goods. The loading and unloading of heavy goods is dangerous, the load of the crane is high, and a large space range is needed during loading, otherwise the goods are easy to collide with fixed objects, other goods and the crane on the ship. Therefore, path planning is particularly important for the loading and unloading of heavy goods on the heavy lift ship.

[0003] In the existing research on automatic path planning, kinematics principle is used to calculate the path and automatic path search algorithm is used to generate the path. However, in the actual simulation process of the lifting path, the data of the actual wharf, goods, ship and crane are still needed to generate a lifting path that can be used to complete the lifting task. The lifting path should meet the requirements of safety, stability and operation specification.

[0004] Therefore, there is an urgent need for a four-degree-of-freedom double-crane path planning method to meet the current demand for lifting path planning. SUMMARY

[0005] In view of the deficiencies of the prior art, the present application provides a four-degree-of-freedom double-crane path planning method, system, device and medium.

[0006] The first aspect of the present application discloses a four-degree-of-freedom double-crane path planning method, comprising:

[0007] analyzing the degree-of-freedom system of the double crane based on kinematics principle, and constructing a four-degree-of-freedom model of the double crane;

[0008] obtaining lifting task information, determining target tasks and target path types;

[0009] calculating the motion parameters of the target path based on the kinematics of the four-degree-of-freedom model, and generating the simplest target path and the shortest target path according to the motion parameters;

[0010] determining the optimal path in the target path according to the span constraint and the collision constraint.

[0011] In an optional embodiment, the analysis of the degree-of-freedom system of the double crane based on kinematics principle comprises:

[0012] The span of the crane is coupled with the inclination angle as a pair of coupling parameters, and a sub-degree of freedom is set for the process of changing the span or the inclination angle, which is used to constrain the hook head height of the main crane and the auxiliary crane to always keep dynamic balance under the change of the boom movement parameter.

[0013] In an optional embodiment, a four-degree-of-freedom model of the double crane is built, including:

[0014] According to the constraint of the sub-degree of freedom, the six-degree-of-freedom system of the double crane is projected on a two-dimensional plane to form a four-bar linkage mechanism, the first boom is defined as a driving link, and the second boom, the hook point connecting line and the rotation center connecting line are defined as driven links, and the driving link and the driven link are controlled according to the driving parameter and the driven parameter to simulate the double crane system and build a four-degree-of-freedom model.

[0015] In an optional embodiment, the hoisting task information is obtained, and the target task and the target path type are determined, including:

[0016] The cargo information, the ship information and the crane information are obtained, the target task is determined according to the lifting point and the landing point position of the cargo information, and the target task includes the loading task and the unloading task;

[0017] The target path type is determined according to the cargo information, the ship information and the crane span information, and the target path type includes the same side hoisting path, the different side hoisting path and the cabin hoisting path.

[0018] In an optional embodiment, the kinematics of the double crane is calculated based on the four-degree-of-freedom model to obtain the motion parameters of the target path, and the simplest target path is generated according to the motion parameters, including:

[0019] The four-degree-of-freedom model parameters are initialized, and the hoisting task information, the target task and the target path type are imported;

[0020] The driving link and the driven link in the four-degree-of-freedom model are determined according to the imported information;

[0021] The lifting position of the target path is determined by adjusting the crane span;

[0022] The first rotation parameter of the first boom is calculated according to the driving link and the target path type, and the first driven parameter of the driven link is calculated in the four-degree-of-freedom model according to the first rotation parameter;

[0023] The crane span corresponding to the second rotation parameter is determined, the second rotation parameter of the second boom is calculated by reselecting the driving link, and the second driven parameter of the driven link is calculated in the four-degree-of-freedom model according to the second rotation parameter;

[0024] According to the first rotation parameter, the first driven parameter, the second rotation parameter and the second driven parameter, the movement trajectory of the first and second jibs is obtained, the center point of the connecting line of the lifting points in the movement trajectory is calculated to generate the shortest target path.

[0025] In an optional embodiment, the four-degree-of-freedom model is used to calculate the kinematics of the double-Crane to obtain the movement parameters of the target path, and the shortest target path is generated according to the movement parameters, comprising:

[0026] The four-degree-of-freedom model parameters are initialized, and the lifting task information, target task and target path type are imported;

[0027] The intermediate point position of the cargo through the connecting line of the rotation center is calculated according to the imported information, and the driving link and the driven link in the four-degree-of-freedom model are determined according to the intermediate point position;

[0028] The first movement parameter of the first driving link is calculated according to the intermediate point by using a spiral curve, and the second movement parameter of the second driving link satisfying the movement of the four-degree-of-freedom model is calculated according to the distance between the lifting points;

[0029] The shortest target path is solved according to the first and second movement parameters.

[0030] In an optional embodiment, the optimal path in the target path is determined according to the span constraint and the collision constraint, comprising:

[0031] The span-load curve of the double-Crane under the four-degree-of-freedom model is constructed according to the ship information associated with the sub-freedom degree;

[0032] The maximum span and the minimum span are determined according to the projection of the jib on the four-degree-of-freedom plane to determine the span range;

[0033] The target path satisfying the span constraint condition is screened according to the span range and the span-load curve;

[0034] The lifting associated entity is created according to the cargo information and the ship information, and the target path is screened by using the collision detection algorithm combined with the span constraint until the distance between the cargo and the collision body is minimum, and the optimal path is output.

[0035] The second aspect of the present application discloses a four-degree-of-freedom double-lifting path planning system, comprising:

[0036] The model construction module is used to analyze the freedom degree system of the double-Crane according to the kinematics principle, and construct the four-degree-of-freedom model of the double-Crane;

[0037] The task confirmation module is used to obtain the lifting task information, determine the target task and the target path type;

[0038] a path solving module, configured to calculate motion parameters of a target path based on a four-degree-of-freedom model for kinematic solution of the double-krillen crane, and generate a shortest target path and a most simple target path according to the motion parameters;

[0039] a path output module, configured to determine an optimal path in the target path according to the span constraint and the collision constraint.

[0040] In an optional embodiment, the analysis of the degree-of-freedom system of the double-krillen crane in the model construction module according to the kinematic principle comprises:

[0041] the span and the pitch angle of the krillen crane are set as a pair of coupled parameters, and a sub-degree-of-freedom is set for the process of changing the span or the pitch angle, the sub-degree-of-freedom is used to constrain the hook head heights of the main crane and the auxiliary crane to keep dynamic balance at all times under the change of the motion parameters of the crane arms.

[0042] In an optional embodiment, the construction of the four-degree-of-freedom model of the double-krillen crane in the model construction module comprises:

[0043] the six-degree-of-freedom system of the double-krillen crane is projected on a two-dimensional plane to form a four-bar linkage motion mechanism according to the constraint of the sub-degree-of-freedom, the first crane arm is defined as a driving link, and the second crane arm, the crane point connecting line and the rotation center connecting line are defined as driven links, and the driving link and the driven link are controlled according to the driving parameters and the driven parameters to simulate the motion of the double-krillen crane system and construct the four-degree-of-freedom model.

[0044] In an optional embodiment, the task confirmation module comprises:

[0045] obtaining cargo information, ship information and krillen crane information, determining a target task according to the lifting point and the landing point positions of the cargo information, the target task comprising a loading task and an unloading task;

[0046] determining the target path type according to the cargo information, the ship information and the krillen crane span information, the target path type comprising a same-side hoisting path, a different-side hoisting path and an in-cabin hoisting path.

[0047] In an optional embodiment, the path solving module comprises:

[0048] initializing the four-degree-of-freedom model parameters, importing the hoisting task information, the target task and the target path type;

[0049] determining the driving link and the driven link in the four-degree-of-freedom model according to the imported information.

[0050] Adjusting the span of the crane to determine the lifting position of the target path;

[0051] According to the type of the target path, determine the first rotation parameter of the first lifting arm calculated by the driving link, and calculate the first driven parameter of the driven link under the four-degree-of-freedom model according to the first rotation parameter;

[0052] Determine the span of the crane corresponding to the second rotation parameter, reselect the driving link to calculate the second rotation parameter of the second lifting arm, and calculate the second driven parameter of the driven link under the four-degree-of-freedom model according to the second rotation parameter;

[0053] According to the first rotation parameter, the first driven parameter, the second rotation parameter, and the second driven parameter, obtain the motion trajectory of the first lifting arm and the second lifting arm, and calculate the motion trajectory of the cargo according to the center point of the connecting line of the lifting point in the motion trajectory to generate the shortest target path.

[0054] In an optional embodiment, the path solving module calculates the motion parameters of the target path based on the four-degree-of-freedom model for kinematics solving of the double-crane, and generates the shortest target path according to the motion parameters, comprising:

[0055] Initialize the parameters of the four-degree-of-freedom model, import the lifting task information, target task, and target path type;

[0056] According to the imported information, calculate the intermediate point position of the cargo through the center connecting line of the rotation, and determine the driving link and the driven link in the four-degree-of-freedom model according to the intermediate point position;

[0057] According to the intermediate point, calculate the first motion parameter of the first driving link by using a spiral curve, and calculate the second motion parameter of the second driving link that satisfies the motion of the four-degree-of-freedom model according to the distance between the lifting points;

[0058] Solve the shortest target path according to the first motion parameter and the second motion parameter.

[0059] In an optional embodiment, the path output module determines the optimal path in the target path according to the span constraint and the collision constraint, comprising:

[0060] According to the ship information, associate the sub-freedom to construct the span-load curve of the double-crane under the four-degree-of-freedom model;

[0061] According to the projection of the lifting arm on the four-degree-of-freedom plane, determine the maximum span and the minimum span, and determine the span range;

[0062] According to the span range and the span-load curve, screen the target path that satisfies the span constraint condition;

[0063] According to the cargo information and the ship information, a lifting association entity is created, a collision detection algorithm is used to screen the target path in combination with the span constraint until the distance between the cargo and the collision body is minimum, and an optimal path is output.

[0064] The third aspect of the present application discloses a four-degree-of-freedom double-crane path planning device, comprising:

[0065] at least one processor, and

[0066] a memory in communication connection with the at least one processor; wherein

[0067] The memory stores instructions executable by the at least one processor, and the instructions are executed by the at least one processor to enable the at least one processor to perform the four-degree-of-freedom double-crane path planning method according to any one of the first aspect of the present application.

[0068] The fourth aspect of the present application discloses a computer readable storage medium, which stores computer executable instructions for causing a computer to execute the four-degree-of-freedom double-crane path planning method according to any one of the first aspect of the present application.

[0069] Compared with the prior art, the present application has the following advantages:

[0070] The method for automatically searching for feasible paths by kinematics and mechanism calculation can generate various paths by changing initial parameters and rotation angles and span parameters at each intermediate stage, so as to obtain paths that meet actual operation requirements and specifications more, and select an optimal path from the generated various paths by calculating and evaluating indexes such as operation transformation steps, total moving distance, and closest distance between the cargo and other objects, which can be integrated into a double-crane simulation training system of a heavy crane ship, and can realize lifting of cargos such as RTG, cruise ship, high-speed train, and wind power blade through examples, and can also meet safety and stability of lifting tasks in actual operation of the heavy crane ship. BRIEF DESCRIPTION OF DRAWINGS

[0071] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings needed in the embodiments or prior art description will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor.

[0072] Figure 1 The flowchart of the four-degree-of-freedom double-crane path planning method of the present application;

[0073] Figure 2 Fig. 1 is a schematic diagram of a four-degree-of-freedom dual-ho path planning system of the present application. DETAILED DESCRIPTION

[0074] In order to make the objects, technical solutions and advantages of the present application clearer, the present application will be described and illustrated below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and should not be used to limit the present application. Based on the embodiments provided by the present application, all other embodiments obtained by those of ordinary skill in the art without creative effort belong to the scope of the present application.

[0075] Obviously, the accompanying drawings in the following description are only some examples or embodiments of the present application, and for those of ordinary skill in the art, the present application can be applied to other similar scenarios without creative effort based on these drawings. In addition, it can be understood that although the efforts made in this development process can be complex and lengthy, for those of ordinary skill in the art related to the content disclosed in the present application, some design, manufacture or production changes based on the technical content disclosed in the present application are only routine technical means and should not be understood as insufficient disclosure of the present application.

[0076] In the present application, the phrase "embodiment" means that the specific features, structures or characteristics described in conjunction with the embodiment can be included in at least one embodiment of the present application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment to other embodiments. It is explicitly and implicitly understood by those of ordinary skill in the art that the embodiments described in the present application can be combined with other embodiments without conflict.

[0077] Unless otherwise defined, the technical or scientific terms used in this application shall have the ordinary meaning understood by one of ordinary skill in the art to which this application pertains. The terms “a,” “an,” “an,” “the,” and similar words used in this application do not indicate quantity limitation and may indicate singular or plural. The terms “comprising,” “including,” “having,” and any variations thereof used in this application are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or device that includes a series of steps or modules (units) is not limited to the listed steps or units, but may also include steps or units not listed, or may include other steps or units inherent to these processes, methods, products, or devices. The terms “connected,” “linked,” “coupled,” and similar words used in this application are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. “Multiple” used in this application refers to two or more. “And / or” describes the relationship between related objects, indicating that three relationships may exist; for example, “A and / or B” can represent: A alone, A and B simultaneously, and B alone. The character " / " generally indicates that the preceding and following objects are in an "or" relationship. The terms "first," "second," and "third" used in this application are merely to distinguish similar objects and do not represent a specific ordering of the objects.

[0078] Example 1

[0079] See Figure 1 This invention discloses a four-degree-of-freedom dual-crane path planning method, comprising:

[0080] 101. Analyze the degree-of-freedom system of the double crane based on the principles of kinematics, and construct a four-degree-of-freedom model of the double crane;

[0081] In an optional embodiment, the kinematic analysis of the degrees of freedom of the double crane includes:

[0082] The span and pitch angle of the crane are set as a pair of coupled parameters. Sub-degrees of freedom are set for the process of changing the span or pitch angle. The sub-degrees of freedom are used to constrain the hook height of the main crane and the auxiliary crane to always maintain dynamic balance under the change of boom motion parameters.

[0083] Specifically, several conditions must be met when planning loading and unloading routes. The loads of the two cranes should be within their operating range. At the loading and unloading points and throughout the entire process, the span of the cranes must not exceed the maximum span determined by their load-span curve. To ensure the stability of the loading and unloading process, the slings of the two cranes should be kept as vertical as possible.

[0084] Further, in the path planning, the single crane and double crane cases need to be considered. A single crane can be regarded as a three-degree-of-freedom system, and the position of the hook is controlled by the rotation, pitch and hook height. When the double cranes are operated, the hooks of the cranes are bound to the cargo hoisting points, and the cargo will not be lifted after the cargo is hoisted to the predetermined hoisting height. Therefore, the double crane system forms a six-degree-of-freedom system through the connection of the cargo. In the path planning, since the cargo hoisting height is constant and the hook heights of the two cranes remain fixed, the system formed by the double cranes and the cargo can be regarded as a four-degree-of-freedom system controlled by the rotation angle of the crane and the pitch angle (i.e. changing the pitch angle of the crane boom will change the span of the boom), which can reduce the number of variable parameters in the path planning and increase the feasibility and accuracy of the generated path in the simulation of the actual lifting process in the case where some parameters have little effect on the path planning result.

[0085] In an optional embodiment, the four-degree-of-freedom model of the double crane is constructed, including:

[0086] According to the constraints of the sub-freedom degrees, the six-degree-of-freedom system of the double crane is projected onto a two-dimensional plane to form a four-bar linkage mechanism. The first boom is defined as the driving link, and the second boom, the hoisting point connecting line and the rotation center connecting line are defined as the driven links. The motion of the driving link and the driven link is controlled according to the driving parameters and the driven parameters to simulate the double crane system and construct the four-degree-of-freedom model.

[0087] Specifically, the tail of the ship body is set as the origin, the bow direction is set as the X-axis and the port side direction is set as the Y-axis, thereby establishing the coordinate system of the crane in the two-dimensional plane. The crane is controlled by the rotation, pitch and hook height of the two booms. When the boom is pitched, the pitch handle and the hoisting rope lifting handle need to be operated simultaneously to ensure the constant hook height. The double crane, the cargo and the ship body form a four-degree-of-freedom planar linkage mechanism. The motion control parameters of the mechanism include the rotation angle and the span of the double crane, wherein the span and the pitch angle are a pair of coupled parameters. In the mechanism control and path planning, the parameters are calculated as a mechanism parameter.

[0088] Further, in the actual lifting operation, in order to generate a more accurate and safe path, the rotation and pitch operations of the crane should be performed independently as much as possible according to the operation specifications of the crane. The generated path can be represented by the projections of the hooks of the two cranes on the horizontal XY plane. The motion trajectory of each crane hook on the plane is composed of a circular arc formed by the rotation of the crane and a straight line formed by the pitch. The motion trajectory of the cargo is determined by the coordinates of the center point of the cargo and the rotation angle of the cargo around its center.

[0089] Further, the double-hoisting four-degree-of-freedom model takes the quadrangle formed by the connection line of ABCD four points as an example, wherein A and B are the rotation centers of the main and auxiliary cranes, AD and BC are the hoisting arms of the double crane, and CD is the connection line of the cargo hoisting points. In the double-crane movement with the planned path, the BC edge (the second hoisting arm) rotates, the BC edge (the second hoisting arm) and the AD edge (the first hoisting arm) remain unchanged, and the AD edge (the first hoisting arm) rotates, forming the double-crane rotation movement. If the length of BC (the second hoisting arm) changes (that is, the change of the hoisting arm pitch angle leads to the change of the projection length of the hoisting arm in the two-dimensional plane), the ∠ABC (the angle between the connection line of the rotation centers and the second hoisting arm) remains unchanged, and AD (the first hoisting arm) rotates, forming the main hoist pitch and the auxiliary hoist rotation. In the double-crane operation, the four-bar linkage mechanism is simplified as one driving pair and three driven pairs, and the movement of the entire mechanism is driven according to the driving parameters: the rotation angle and the pitch angle.

[0090] Further, in the four-degree-of-freedom model, the movement parameters of the double-crane are calculated, the double-crane cooperates in hoisting, and the rotation angle, the pitch angle (span), and the hoisting rope length of the double-crane need to be controlled. Each crane has three parameters to describe the state in the movement. In the hoisting path planning, the actual control is the position of the hook in the space, including the X, Y, and Z coordinates. If the large hook (main hook) or the auxiliary hook used on the crane is selected, the length of the hoisting arm of the crane can be determined. The inherent parameters of the crane include the hoisting arm length L B , and the movement parameters of the crane as variables include the rotation angle θ, the pitch angle β, and the hoisting rope length S. The coordinate position of the hook head can be calculated in the four-degree-of-freedom model coordinate system through the above parameters, wherein the X coordinate HK x =C x +L B *cosθ, C x is the coordinate of the crane rotation center in the x-axis direction, the Y coordinate HK y =C y +L B *sinθ, wherein C y is the coordinate of the crane rotation center in the y-axis direction, and the Z coordinate HK z =C z +L B *sinβ-S, wherein C z is the coordinate of the crane rotation center in the Z-axis, and S is the hoisting rope length.

[0091] Further, in the hoisting of a large piece, the cargo needs to be kept at the hoisting height after being hoisted. Therefore, the hoisting rope length and the pitch are coupled and controlled. When the hoisting arm is lifted to reduce the span, the hook needs to be lowered to keep the hook height unchanged. Therefore, the calculation of the crane movement parameters can be represented as:

[0092] Solving slewing angle of the crane:

[0093] Solving span:

[0094] Solving luffing angle:

[0095] 102, obtaining hoisting task information, determining target task and target path type;

[0096] In an optional embodiment, the obtaining hoisting task information, determining target task and target path type, comprises:

[0097] obtaining cargo information, ship information and crane information, determining target task according to the lifting point and the landing point position of the cargo information, the target task including loading task and unloading task;

[0098] determining the target path type according to the cargo information, ship information and crane span information, the target path type including same-side hoisting path, different-side hoisting path and in-cabin hoisting path.

[0099] Specifically, the division of hoisting tasks is made by analyzing the actual hoisting process of cargos of different sizes, shapes and weights, and the planning tasks are classified in the automatic path planning algorithm. Specifically, according to the position of the cargo lifting point and the landing point, it is determined whether to load or unload the cargo. For same-side hoisting and different-side hoisting, the position of the cargo on the ship can be calculated, wherein the same-side hoisting (the cargo and the crane are on the left side of the ship) and the different-side hoisting (the crane is on the left side, and the cargo is hoisted on the ship from the right side). The same-side hoisting cargo needs to pass through the middle area of the two cranes, the movement trajectory is short, the cargo is close to the centerline of the ship, and a smaller span can be used to complete the hoisting, which is suitable for most cargos and yachts, tugboats and other cargos that need to be hoisted from the water surface. When the same-side hoisting is performed, the cargo needs to pass through the middle of the two cranes. For large cargos, the hoisting trajectory is relatively complex. Different-side hoisting is mainly applied to super large cargos such as wind power blades, which requires a larger span and a relatively simple hoisting path.

[0100] Further, if the cargo falls on the hatch cover or in the cabin: according to the position and height of the landing point, it is determined whether the cargo falls on the hatch cover or in the cabin (the bottom of the cabin or the bypass plate of the cabin). The task of falling in the cabin needs to calculate the position and angle of the cargo entering the cabin. After the cargo completely enters the cabin, the path planning of the in-cabin movement needs to be performed.

[0101] Further, after the simulation platform completes the selection of the cargo lifting point and the cargo dropping point, the data of the ship body, the ship cabin, the cargo winch, and the cargo are imported into the path planning algorithm module through a data file. Before lifting, the path planning module imports data, initializes the double-lifting system, completes the lifting task type calculation, such as loading, unloading, same side, and opposite side, performs double-cargo winch load calculation, verifies that the load is within the cargo winch load range, calculates the initial lifting position and the cargo dropping position, and determines whether the lifting task is within the cargo winch working range according to the cargo winch parameters and the load-span curve. The collision between the cargo at the lifting and dropping positions and the cargo winch, the fixed objects on the ship, and other obstacles is calculated.

[0102] 103. calculating the motion parameters of the target path based on the kinematics of the double cargo winch according to the four-degree-of-freedom model, and generating the simplest target path and the shortest target path according to the motion parameters;

[0103] Specifically, after the lifting task data is imported, the algorithm first checks the state of the cargo at the lifting and dropping points, including the cargo winch load, span, collision, and the like. In double-lifting cooperative lifting, one cargo winch is usually used as the main lifting winch, and the other cargo winch cooperates with the main lifting winch to complete lifting. The algorithm determines the main lifting winch according to the cargo lifting point position, the cargo shape, the obstacle distribution, and the like, and then starts the path automatic planning.

[0104] Further, when planning the path, it is generally divided into the simplest operation path (i.e., the lifting path with the optimal simplified cargo winch operation amount) and the shortest operation path (i.e., the lifting path with the shortest cargo movement distance). Specifically, in the simplest operation path (the simplest target path), the cargo winch only performs a single operation such as rotation or pitching at one time during the movement process, and does not simultaneously perform rotation or pitching. The pitching and the lifting of the lifting hook are compound operations, which require lifting the lifting arm while lowering the lifting hook. The shortest operation path (i.e., the shortest target path) requires that the key position points in the path should meet the movement law of the four-degree-of-freedom system formed by the cargo winch, and the rotation and pitching angle (span) of the driving mechanism is calculated to calculate the key path points.

[0105] In an optional embodiment, the calculating the motion parameters of the target path based on the kinematics of the double cargo winch according to the four-degree-of-freedom model, and generating the simplest target path according to the motion parameters, comprises:

[0106] initializing the four-degree-of-freedom model parameters, importing the lifting task information, the target task, and the target path type;

[0107] determining the driving link and the driven link in the four-degree-of-freedom model according to the imported information;

[0108] adjusting the cargo winch span to determine the lifting position of the target path;

[0109] determining a first slewing parameter of the first crane boom according to the target path type, and calculating a first driven parameter of the driven link under a four-degree-of-freedom model according to the first slewing parameter;

[0110] determining a second slewing parameter of the second crane boom according to the target path type, and calculating a second driven parameter of the driven link under the four-degree-of-freedom model according to the second slewing parameter;

[0111] acquiring a motion trajectory of the first crane boom and the second crane boom according to the first slewing parameter, the first driven parameter, the second slewing parameter and the second driven parameter, and generating the simplest target path according to a center point of a connecting line of the two lifting points in the motion trajectory.

[0112] Specifically, the automatic path planning algorithm divides the hoisting process into five stages to complete. Taking the simplest target path as an example, in the first stage, the positions of the two lifting points of the cargo in the ship coordinate system are calculated according to the cargo lifting and placing position, so as to calculate the slewing angle and the pitch angle of the two crane booms at the lifting position and the length of the sling according to the coordinates of the hooks. Further, in the first stage, the span of the double crane, the distance from the cargo to the ship side and the slewing angle of the two crane booms are checked when the cargo is at the lifting position. During the cargo hoisting process, the cargo will make slewing motion relative to the crane around the hook as the slewing center, and it is required to ensure that no collision occurs in the slewing. The span of the lifting should be greater than the length from the lifting point of the cargo to the boundary position of the cargo and less than the slewing span. If the requirement is not met, the lifting position can be adjusted or the span of the double crane can be changed after lifting to the hoisting height to meet the requirements of subsequent slewing.

[0113] Further, in the second stage, the main crane (first crane arm) rotates to move the cargo end lifting point to the inside of the ship. When loading the cargo, the main crane (first crane arm) should rotate at an angle such that the hook of the main crane (first crane arm) enters the inside of the ship, and the cargo end passes through the double crane X center line. The rotation angle is calculated according to the double crane span, cargo lifting point distance, etc. to ensure that the rotation angle is within the permitted range of the four-degree-of-freedom model planar mechanism. Specifically, during hoisting, the projection of the hook on the horizontal plane should always be within the range of two concentric circles. The outer circle is the maximum span determined by the actual load of a single crane, which is determined by the crane load-span curve. The inner circle is the minimum span of the crane itself. At different relative angles of the cargo and the crane arm, the closest distance between the cargo and the arm also needs to be calculated, which should always be greater than the minimum safe distance of collision, and the minimum span range of the crane should be controlled. According to the shape, size of the cargo, double crane distance, lifting point distance, etc. parameters, the first rotation angle of the main crane is calculated to ensure that the cargo enters the inside of the ship and does not collide with the crane base, arm, etc. Assuming that the horizontal projection shape of the cargo is a rectangle, it should be ensured that the two endpoints of the rectangle near the main crane side move through the double crane line, thereby determining the angle at which the cargo has passed the closest position to the main crane.

[0114] Further, in the third to fifth stages, the double crane span is adjusted to prepare for the second crane rotation. Especially for super large cargo, before the second rotation, the double crane span needs to be adjusted according to the cargo size and collision situation to ensure that the second rotation crane has the minimum span and the first crane span meets the requirements of the four-degree-of-freedom model planar linkage mechanism. It should be noted that (the second span adjustment ensures that the cargo at one end of the secondary crane can pass through the closest distance to the second crane. The previous main crane adjusts the span to ensure that it does not collide with the existing cargo on the ship); then the fourth stage of the secondary crane rotation is performed. Through the rotation of the secondary crane, the cargo is completely hoisted to the cargo platform range. The rotation angle is calculated according to the crane rotation angle when the cargo is dropped, the cargo drop position and angle, etc.; finally, the fifth stage is performed, and the cargo is adjusted to the drop position to complete the hoisting. The cargo is moved to the final drop position through translation, rotation, etc.

[0115] In an optional embodiment, the four-degree-of-freedom model is used to calculate the kinematics of the double crane to obtain the motion parameters of the target path, and a shortest target path is generated according to the motion parameters, comprising:

[0116] The four-degree-of-freedom model parameters are initialized, and the hoisting task information, target task and target path type are imported;

[0117] According to the imported information, the intermediate point position of the cargo passing through the rotation center line is calculated, and the driving link and driven link in the four-degree-of-freedom model are determined according to the intermediate point position.

[0118] According to the intermediate point, the first movement parameter of the first driving link is calculated by using a spiral curve, and the second movement parameter of the second driving link satisfying the four-degree-of-freedom model movement is calculated according to the distance between the two lifting points;

[0119] The shortest target path is solved according to the first movement parameter and the second movement parameter.

[0120] Specifically, the shortest target path part step can be solved by referring to the simplest target path, and the main steps include calculating the positions of the goods capable of passing through the goods, determining which crane to drive the four-degree-of-freedom mechanism movement according to the slewing angle and span length of the two cranes corresponding to the intermediate point position, calculating the span and slewing angle satisfying the mechanism configuration condition according to the distance between the lifting points of the secondary crane, and realizing the solution of the four-degree-of-freedom model link mechanism, wherein the double-crane system drives movement according to the generated two slewing angles and two span lengths.

[0121] 104. Determine the optimal path in the target path according to the span constraint and the collision constraint.

[0122] In an optional embodiment, the determination of the optimal path in the target path according to the span constraint and the collision constraint comprises:

[0123] According to the ship information, the span-load curve of the double crane under the four-degree-of-freedom model is constructed according to the sub-degree-of-freedom.

[0124] According to the projection of the lifting arm on the four-degree-of-freedom plane, the maximum span and the minimum span are determined to determine the span range.

[0125] According to the span range and the span-load curve, the target path satisfying the span constraint condition is screened.

[0126] According to the cargo information and the ship information, a lifting-related entity is created, and a collision detection algorithm is used in combination with the span constraint to screen the target path until the distance between the goods and the collision body is minimized, and the optimal path is output.

[0127] Specifically, in the automatic path planning, real-time collision checking between the cargo and the ship body, the crane, other cargos needs to be carried out. In view of the efficiency and accuracy of the collision checking, the application adopts two kinds of algorithms, the fast collision checking based on OBB and the GJK collision checking based on convex polyhedron grid. For the cargo, the crane base, the crane boom, the cargo on the ship, the fixed objects on the ship and the like, the OBB describing the maximum shape and the convex polyhedron unit describing the internal details are constructed. The fast collision checking of the collision body is carried out through the OBB, and if the OBB collides, the GJK algorithm is called to carry out the accurate collision checking. In order to ensure that the cargo and other objects have a certain safety distance during the hoisting process, the minimum distance algorithm of the GJK is adopted here, and the accurate collision judgment is carried out by calculating the minimum distance between the collision bodies.

[0128] The application can generate various paths by changing the initial parameters and the rotation angle and span parameters of each intermediate stage, so as to obtain a path more in line with the actual operation requirements and specifications, and calculate and evaluate the operation transformation steps, the total moving distance, and the closest distance between the cargo and other objects, so as to select the optimal path from the multiple paths, which can be integrated into the double-crane simulation training system of the heavy-lift ship, and can realize the hoisting of RTG, cruise ship, high-speed train, wind power blade and the like through examples, and can also meet the safety and stability of the hoisting task in the actual operation of the heavy-lift ship.

[0129] As shown in Figure 2 The second aspect of the application discloses a four-degree-of-freedom double-crane path planning system, which comprises:

[0130] A model construction module is configured to analyze the degree-of-freedom system of the double crane based on the kinematics principle and construct a four-degree-of-freedom model of the double crane.

[0131] A task confirmation module is configured to obtain hoisting task information and determine a target task and a target path type.

[0132] A path solving module is configured to calculate the motion parameters of the target path based on the kinematics of the four-degree-of-freedom model of the double crane, and generate a simplest target path and a shortest target path according to the motion parameters.

[0133] A path output module is configured to determine the optimal path in the target path according to the span constraint and the collision constraint.

[0134] In an optional embodiment, the model construction module comprises:

[0135] The span of the crane is coupled with the pitch angle as a pair of coupling parameters, and a sub-degree of freedom is set for the process of changing the span or the pitch angle, which is used to constrain the hook height of the main crane and the auxiliary crane to always keep dynamic balance under the change of the boom movement parameter.

[0136] In an optional embodiment, a four-degree-of-freedom model of the double crane is constructed in the model construction module, including:

[0137] According to the constraint of the sub-degree of freedom, the six-degree-of-freedom system of the double crane is projected on a two-dimensional plane to form a four-bar linkage mechanism, the first boom is defined as a driving link, and the second boom, the hook point connecting line and the rotation center connecting line are defined as driven links, and the driving link and the driven link are controlled according to the driving parameter and the driven parameter to simulate the double crane system and construct a four-degree-of-freedom model.

[0138] In an optional embodiment, the task confirmation module obtains the lifting task information, determines the target task and the target path type, including:

[0139] The cargo information, the ship information and the crane information are obtained, the target task is determined according to the lifting point and the landing point position of the cargo information, and the target task includes the loading task and the unloading task;

[0140] The target path type is determined according to the cargo information, the ship information and the crane span information, and the target path type includes the same side lifting path, the different side lifting path and the cabin lifting path.

[0141] In an optional embodiment, the path solving module calculates the motion parameters of the target path based on the four-degree-of-freedom model for the kinematics of the double crane, and generates the simplest target path according to the motion parameters, including:

[0142] The four-degree-of-freedom model parameters are initialized, and the lifting task information, the target task and the target path type are imported;

[0143] The driving link and the driven link in the four-degree-of-freedom model are determined according to the imported information;

[0144] The lifting position of the target path is determined by adjusting the crane span;

[0145] The first rotation parameter of the first boom is calculated according to the driving link and the target path type, and the first driven parameter of the driven link is calculated in the four-degree-of-freedom model according to the first rotation parameter;

[0146] The crane span corresponding to the second rotation parameter is determined, the second rotation parameter of the second boom is calculated by reselecting the driving link, and the second driven parameter of the driven link is calculated in the four-degree-of-freedom model according to the second rotation parameter;

[0147] According to the first rotation parameter, the first driven parameter, the second rotation parameter and the second driven parameter, the movement trajectory of the first and second hoists is obtained, the center point of the hoist point connecting line in the movement trajectory is calculated to generate the shortest target path.

[0148] In an optional embodiment, the path solving module calculates the movement parameters of the target path based on the four-degree-of-freedom model for the kinematics of the double-Crane hoist, and generates the shortest target path according to the movement parameters, including:

[0149] The four-degree-of-freedom model parameters are initialized, and the hoisting task information, target task and target path type are imported;

[0150] The intermediate point position of the cargo passing through the rotation center connecting line is calculated according to the imported information, and the driving link and driven link in the four-degree-of-freedom model are determined according to the intermediate point position;

[0151] The first movement parameter of the first driving link is calculated according to the intermediate point by using a spiral curve, and the second movement parameter of the second driving link satisfying the movement of the four-degree-of-freedom model is calculated according to the hoist point spacing;

[0152] The shortest target path is solved according to the first and second movement parameters.

[0153] In an optional embodiment, the path output module determines the optimal path in the target path according to the span constraint and the collision constraint, including:

[0154] The span-load curve of the double-Crane hoist under the four-degree-of-freedom model is constructed according to the ship information associated with the sub-freedom degree;

[0155] The maximum span and the minimum span are determined according to the projection of the hoist in the four-degree-of-freedom plane to determine the span range;

[0156] The target path satisfying the span constraint condition is screened according to the span range and the span-load curve;

[0157] The hoisting associated entity is created according to the cargo information and the ship information, and the target path is screened by using a collision detection algorithm combined with the span constraint until the distance between the cargo and the collision body is the smallest, and the optimal path is output.

[0158] The third aspect of the present application discloses a four-degree-of-freedom double-hoist path planning device, including:

[0159] At least one processor, and

[0160] The memory in communication connection with the at least one processor; wherein

[0161] The memory stores instructions executable by the at least one processor, and the instructions are executed by the at least one processor to enable the at least one processor to perform the four-degree-of-freedom double-hoist path planning method according to any one of the first aspect of the application.

[0162] The computer device can be a terminal, and the computer device includes a processor, a memory, a network interface, a display screen and an input device connected through a system bus. The processor of the computer device is configured to provide computing and control capabilities. The memory of the computer device includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system and a computer program. The internal memory provides an environment for running the operating system and the computer program in the non-volatile storage medium. The network interface of the computer device is configured to communicate with external terminals through network connection. The computer program is executed by the processor to implement the four-degree-of-freedom double-hoist path planning method. The display screen of the computer device can be a liquid crystal display screen or an electronic ink display screen. The input device of the computer device can be a touch layer overlaid on the display screen, or can be a key, a trackball or a touchpad arranged on the shell of the computer device, or can be an external keyboard, a touchpad or a mouse, etc.

[0163] The fourth aspect of the application discloses a computer readable storage medium, and the computer readable storage medium stores computer executable instructions. The computer executable instructions are configured to enable a computer to perform the four-degree-of-freedom double-hoist path planning method according to any one of the first aspect of the application.

[0164] Those skilled in the art can understand that all or part of the processes in the above-mentioned embodiment methods can be completed by instructing the relevant hardware through a computer program. The computer program can be stored in a non-volatile computer readable storage medium, and when executed, can include the processes of the above-mentioned embodiments of the double-hanging path planning method through four degrees of freedom. In the embodiments provided in the present application, any reference to memory, storage, database or other medium can include non-volatile and / or volatile memory. Non-volatile memory can include read-only memory (ROM), programmable ROM (PROM), electrically programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM) or flash memory. Volatile memory can include random access memory (RAM) or external cache memory. As an illustration but not limitation, RAM is available in various forms, such as static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), double data rate SDRAM (DDR SDRAM), enhanced SDRAM (ESDRAM), synchronous link (Synchlink) DRAM (SLDRAM), memory bus (Rambus) direct RAM (RDRAM), direct memory bus dynamic RAM (DRDRAM), and memory bus dynamic RAM (RDRAM), etc.

[0165] Alternatively, the above-mentioned modules of the present application, if realized in the form of software function modules and sold or used as independent products, can also be stored in a computer readable storage medium. Based on this understanding, the technical solutions of the embodiments of the present application can be embodied in the form of software products, and the computer software products are stored in a storage medium, including a plurality of instructions for causing a computer device (which can be a personal computer, terminal, or network device, etc.) to execute all or part of the embodiments of the present application. The above-mentioned storage medium includes mobile storage devices, RAM, ROM, magnetic or optical disks, and various media that can store program codes.

[0166] The above-mentioned is only the preferred embodiment of the present application, and is not used to limit the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A four-degree-of-freedom dual-crane path planning method, characterized in that, The method includes: Based on the principles of kinematics, the degree-of-freedom system of the double crane is analyzed, and a four-degree-of-freedom model of the double crane is constructed. Obtain hoisting task information and determine the target task and target path type; The kinematic parameters of the target path are calculated by solving the kinematics of the double crane based on the four-degree-of-freedom model, and the simplest target path and the shortest target path are generated based on the kinematic parameters. The optimal path in the target path is determined based on the span constraint and the collision constraint.

2. The four-degree-of-freedom dual-crane path planning method according to claim 1, characterized in that, The kinematic analysis of the double-clinch suspension system includes: The span and pitch angle of the crane are set as a pair of coupled parameters. Sub-degrees of freedom are set for the process of changing the span or pitch angle. These sub-degrees of freedom are used to constrain the hook height of the main crane and the auxiliary crane to always maintain dynamic balance under the change of boom motion parameters.

3. The four-degree-of-freedom dual-crane path planning method according to claim 2, characterized in that, The construction of the four-degree-of-freedom model of the dual-clinch crane includes: Based on the constraints of the sub-degrees of freedom, the six-degree-of-freedom system of the double crane is projected onto a two-dimensional plane to form a four-bar linkage. The first boom is defined as the driving link, and the second boom, the line connecting the lifting point and the line connecting the rotation center are defined as the driven link. The driving link and the driven link are controlled according to the driving parameters and the driven parameters to simulate the movement of the double crane system and construct a four-degree-of-freedom model.

4. The four-degree-of-freedom dual-crane path planning method according to claim 1, characterized in that, The process of obtaining hoisting task information and determining the target task and target path type includes: Obtain cargo information, ship information, and crane information; determine the target task based on the lifting point and unloading point of the cargo information; the target task includes loading task and unloading task. The target path type is determined based on the cargo information, ship information, and crane span information. The target path type includes same-side lifting path, opposite-side lifting path, and in-cabin lifting path.

5. The four-degree-of-freedom dual-crane path planning method according to claim 1, characterized in that, The kinematic solution of the double crane based on the four-degree-of-freedom model calculates the motion parameters of the target path, and generates the simplified target path based on the motion parameters, including: Initialize the parameters of the four-degree-of-freedom model, and import the hoisting task information, target task, and target path type; The driving and driven links in the four-degree-of-freedom model are determined based on the imported information. Adjust the span of the crane to determine the lifting position for the target path; Based on the target path type, the first rotation parameter of the first boom is calculated by determining the driving link, and the first driven parameter of the driven link is calculated in a four-degree-of-freedom model based on the first rotation parameter. Determine the span of the crane corresponding to the second rotation parameter, reselect the drive link and calculate the second rotation parameter of the second boom, and calculate the second driven parameter of the driven link under the four-degree-of-freedom model based on the second rotation parameter. The motion trajectories of the first boom and the second boom are obtained based on the first slewing parameter, the first driven parameter, the second slewing parameter, and the second driven parameter. The simplest target path is generated by calculating the cargo motion trajectory based on the center point of the line connecting the lifting points in the motion trajectory.

6. The four-degree-of-freedom dual-crane path planning method according to claim 1, characterized in that, The process of calculating the kinematic parameters of the target path based on the kinematic solution of the double crane using a four-degree-of-freedom model, and generating the shortest target path based on the kinematic parameters, includes: Initialize the parameters of the four-degree-of-freedom model, and import the hoisting task information, target task, and target path type; Calculate the midpoint position of the line connecting the cargo through the center of rotation based on the imported information, and determine the driving link and driven link in the four-degree-of-freedom model based on the midpoint position; The first motion parameters of the first drive link are calculated using a spiral curve based on the midpoint, and the second motion parameters of the second drive link satisfying the four-degree-of-freedom model motion are calculated based on the distance between the suspension points. The shortest target path is determined based on the first motion parameters and the second motion parameters.

7. The four-degree-of-freedom dual-crane path planning method according to claim 1, characterized in that, Determining the optimal path in the target path based on span constraints and collision constraints includes: Based on the ship information, the span-load curve of the dual-Cring crane under the four-degree-of-freedom model is constructed by associating the sub-degrees of freedom. The maximum and minimum spans are determined based on the projection of the boom onto the four-degree-of-freedom plane, thus defining the span range. Target paths that meet the span constraints are selected based on the span range and the span-load curve. Based on cargo and ship information, a lifting-related entity is created. A collision detection algorithm is used in conjunction with the span constraint to filter the target path until the distance between the cargo and the collision object is minimized, and the optimal path is output.

8. A four-degree-of-freedom dual-crane path planning system, characterized in that, The system includes: The model building module is used to analyze the degree-of-freedom system of the double crane based on kinematic principles and build a four-degree-of-freedom model of the double crane. The task confirmation module is used to obtain hoisting task information and determine the target task and target path type; The path solving module is used to calculate the motion parameters of the target path based on the kinematic solution of the double crane using a four-degree-of-freedom model, and generate the simplest target path and the shortest target path based on the motion parameters. The path output module is used to determine the optimal path among the target paths based on the span constraint and the collision constraint.

9. A four-degree-of-freedom dual-crane path planning device, characterized in that, include: At least one processor, and, A memory communicatively connected to the at least one processor; wherein, The memory stores instructions that can be executed by the at least one processor to enable the at least one processor to perform the four-degree-of-freedom dual-suspension path planning method as described in any one of claims 1 to 7.

10. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores computer-executable instructions for causing a computer to perform the four-degree-of-freedom dual-crane path planning method as described in any one of claims 1 to 7.

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