Three-dimensional boxing planning method based on dynamic grids

Abstract

The invention provides a three-dimensional boxing planning method based on a dynamic grid. The method comprises the following steps: defining constraint conditions of cargo loading; the method comprises the following steps: dispersing a cargo space into three-dimensional grids, and initializing the three-dimensional grids; goods preprocessing, wherein effective goods are screened, and the goods are sorted and grouped; carrying out iterative placement, namely carrying out iterative placement on the preprocessed goods in a three-dimensional grid space; and coordinate conversion: converting the grid coordinates of the placed cargoes into cargo hold space coordinates. According to the method, the cargo hold space is discretized through the dynamic grid, the constraint conditions are defined, and the problem that the applicability is poor due to the fact that an existing loading algorithm ignores actual physical constraints is solved by combining cargo preprocessing and an iterative placement mechanism. The dynamic grids can accurately track the space occupancy state, linkage from planning to execution is achieved in cooperation with coordinate conversion, the space utilization rate, loading stability and automation degree of boxing are remarkably improved, and a set of complete and landing solution is provided for box type goods loading.

Description

Technical Field

[0001] This invention relates to the field of automated loading technology, and in particular to a three-dimensional packing planning method based on dynamic grids. Background Technology

[0002] In the logistics and transportation sector, efficient cargo loading is a key issue for improving transportation efficiency and reducing costs. Currently, the loading of box cargo only involves using palletizers at the end of the assembly line, followed by forklifts, push-pull equipment, and other tools to transfer the goods to the warehouse or transport them to trucks for manual stacking. There is no complete automated loading solution for box cargo.

[0003] Chinese patent CN115367505A discloses an intelligent palletizing algorithm for a box-type loading system, specifically disclosing the following steps: S1, detecting the size of the goods and analyzing the state of the goods on the conveyor belt; S2, calculating how many forward or lateral goods are needed for a row using the algorithm; S3, adjusting the goods on the conveyor belt to the arrangement state required by the palletizing algorithm; S4, the loading robot pushes the fully loaded goods in the end effector.

[0004] However, this patent only detects the size of the goods and calculates how many goods, either facing forward or sideways, are needed in a row. It is the simplest and most basic palletizing solution, and it does not take into account the various constraints on the goods during the loading process (such as how much gap should be reserved between the goods and how to make it easy for the robot end gripper to load the goods into the target position). Its automatic loading algorithm is too idealistic and has very low applicability. Summary of the Invention

[0005] This invention proposes a three-dimensional packing planning method based on dynamic grids, which solves the problems of overly idealistic and poor applicability of existing automatic loading algorithms.

[0006] The technical solution of this invention is implemented as follows: This invention provides a three-dimensional packing planning method based on dynamic meshes, comprising the following steps: Define the constraints for cargo loading; Discretize the cargo hold space into a three-dimensional mesh and initialize the three-dimensional mesh; Cargo preprocessing includes screening valid cargo, sorting and grouping cargo; Iterative placement involves iteratively placing the pre-processed goods within a three-dimensional mesh space according to constraints. Coordinate transformation converts the grid coordinates of the placed cargo into cargo hold space coordinates.

[0007] Specifically, the constraints include: 1) Bottom clearance: The clearance reserved between the bottom of the cargo hold and the first layer of cargo. g f ; 2) Interlayer gap: A vertical gap is reserved between adjacent goods on upper and lower layers. g l ; 3) Horizontal clearance: A horizontal clearance is reserved between adjacent goods on the same floor. g b ; 4) Unusable area at the front: An unusable area is reserved at the front of the cargo hold. L h × W × H ,in W , H These are the width and height of the cargo hold, respectively. L h To reserve the length of unusable areas; 5) Cargo may extend beyond the rear of the cargo hold, provided that the length of the extended portion is proportional to the total length of the cargo. α ; 6) The order of placing cargo in the cargo hold is from bottom to top, from front to back, and from right to left.

[0008] Specifically, the cargo hold space is discretized into a three-dimensional grid. The grid cell size is 10×10×10, and the dimensions of the 3D grid are: , , ; in, L , W , H These are the length, width, and height of the cargo hold, respectively. Define the origin of the 3D mesh coordinate system as the bottom left corner mesh point; Define grid points in a 3D mesh ( r , c , q The state of ) is: G ( r , c , q ) = -1 indicates that the current grid point is in the front unavailable area or the bottom gap area; G ( r , c , q ) = 0 indicates that the current grid is in an empty area; G ( r , c ,q ) = 1 indicates that the current mesh is in the interlayer gap or horizontal gap region; G ( r , c , q ) = 2, indicating that the current grid point is in the cargo-occupied area; Initialize the state of all grid points in the 3D mesh: ; Initialize the corner point set P Starting corner of the cargo hold p 0 The starting corner point is used to place the bottom right corner of the first item.

[0009] Specifically, cargo pretreatment includes the following steps: Input the goods collection: ; No. i Each item is represented as: , i =1,2,…, n , n The total number of goods; in, s i For the first i A type label for each item, used to indicate the type of item; l i , w i , h i The first i The length, width, and height of each item; m i Indicates the first i The weight of each item; The set of valid goods is as follows: ; in, L , W , H These are the length, width, and height of the cargo hold, respectively. Goods are sorted according to the following priority: Cargo height priority > Cargo base area priority > Cargo length priority; The goods are grouped by type, and the resulting collection of goods is: ; in, S This is a collection of labels for all goods types.

[0010] Specifically, during the iterative placement process, if the set of corner points... P If the item is not empty and there are still goods to be placed, perform the following steps: From the corner point set P Selecting corner points ,in, Iterate through all cargo types, select the cargo with the largest volume, and check if the selected cargo can be placed in a corner. ; If possible, update the grid state and corner point set. P Then continue to select new corner points for placement; if not, select goods with a lower priority according to the order of goods priority, until the selected goods can be placed at the corner point.

[0011] Further, checking whether the goods can be placed in a corner includes: a) Spatial inspection: The space occupied by the goods is: ; in, r i = l i / 10, c i = w i / 10, q i = h i / 10; r i , c i , q i The length of the current cargo l i ,Width w i ,high h i Number of grid cells occupied; The inspection conditions are: ; b) Stability check: like q = g f If it is stable, then check the support layer below the cargo: ; Where II is the indicator function; c) Placement location validity check, including: Placement conflict detection: ; Check if there are any goods on the left side of the placement location: ; Check if there is any goods to the right of the placement location, and whether the length of the goods to the right is greater than 90% of the length of the current goods: ; ; in, This indicates the column index of the first detected item on the right. Check if the height of the goods on the right is higher than 80% of the height of the current goods: ; Check if the height of the adjacent item on the right is greater than 80% of the height of the current item: ; d) Weight check: ; in, M The total weight of the cargo already placed in the cargo hold. m i The current weight of the goods. M max This is the maximum load capacity of the cargo hold.

[0012] Furthermore, if the selected goods can be placed at a corner point, then: Update the grid status as follows: ; Set horizontal gap: ; Updated total weight: M = M + m i ; Record placement location: ; p i Let be the coordinates of the geometric center of the i-th item in the grid; Update the corner point collection: ; Each corner point must meet the following conditions: .

[0013] Preferably, after iterative placement, the goods are adjusted for symmetry: Calculate the column coordinates of the leftmost and rightmost cargo in the cargo hold: ; in, c min , c max These are the column coordinates of the leftmost and rightmost cargo in the cargo hold, respectively. Q A collection of goods that have already been placed; Get the width of the leftmost and rightmost cargo in the cargo hold: ; in, w min , w max These are the widths of the cargo on the far left and far right of the cargo hold, respectively. Calculate left and right space: ; in, s left This refers to the distance between the leftmost cargo and the left side panel of the cargo hold. s right The distance between the rightmost cargo and the right side panel of the cargo hold; Calculate the offset: ; If b ≥ 0, then adjust the coordinates: .

[0014] Specifically, the coordinate transformation formula is as follows: ; in, Let be the origin of the cargo hold spatial coordinate system. Z The positive direction of the axis points towards the ground; Indicates the first i The coordinates of the bottom center of each cargo within the cargo hold spatial coordinate system.

[0015] Compared with the prior art, the beneficial effects of the present invention are as follows: (1) This invention discretizes the cargo hold space using dynamic grids and strictly defines multi-dimensional constraints. Combined with cargo preprocessing and iterative placement mechanisms, it solves the problem of poor applicability caused by existing automatic loading algorithms ignoring actual physical constraints. Dynamic grid management can accurately track the space occupancy status and, with coordinate transformation, achieve the connection from planning to execution, significantly improving the space utilization, loading stability, and automation level of container loading, providing a complete and feasible solution for containerized cargo loading. (2) This invention ensures that the algorithm meets the actual loading requirements and improves the feasibility of the scheme by defining spatial constraints such as bottom gap, inter-layer gap, horizontal gap, and unusable area at the front of the cargo compartment; and optimizes the space utilization rate by finely modeling the available space and unusable area through grid state modeling. (3) This invention prioritizes and groups goods according to height, bottom area and length to improve loading density and efficiency; combined with corner point set dynamic update and stability check, it ensures loading safety and rationality; through symmetry adjustment mechanism, it balances the weight distribution in the width direction of the cargo hold and reduces the risk of off-center loading in transportation. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 This is a flowchart illustrating a three-dimensional packing planning method based on dynamic mesh according to the present invention. Figure 2 This is a schematic diagram of the cargo hold grid spatial coordinate system in an embodiment of the present invention. Detailed Implementation

[0018] The technical solution of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0019] Reference Figure 1 This invention provides a three-dimensional packing planning method based on dynamic meshes, comprising the following steps: S1 defines the constraints for loading cargo; The constraints include: 1) Bottom clearance: The clearance reserved between the bottom of the cargo hold and the first layer of cargo. g f (Unit: cm) 2) Interlayer gap: A vertical gap is reserved between adjacent goods on upper and lower layers. g l (Unit: cm) 3) Horizontal clearance: A horizontal clearance is reserved between adjacent goods on the same floor. g b (Unit: cm) 4) Unusable area at the front: An unusable area is reserved at the front of the cargo hold (front of the carriage). L h × W × H ,in W , H These are the width and height of the cargo hold, respectively (unit: millimeters). L h Length of the unusable area (unit: centimeters); 5) Cargo may extend beyond the rear end of the cargo hold (rear of the vehicle), provided that the length of the extended portion is proportional to the total length of the cargo. ; 6) The order of placing cargo in the cargo hold is from bottom to top, from front to back, and from right to left.

[0020] In addition, it is necessary to ensure that the equipment for placing goods is placed smoothly and does not interfere with other goods.

[0021] S2, discretize the cargo hold space into a three-dimensional mesh and initialize the three-dimensional mesh; Discretize the cargo hold space into a three-dimensional mesh. The mesh unit size is 10mm × 10mm × 10mm, and the dimensions of the 3D mesh are: , , ; in, L , W , H These are the length, width, and height of the cargo hold (unit: millimeters). Define the origin of the 3D mesh coordinate system as the bottom left corner mesh point; Define grid points in a 3D mesh ( r , c , q The state of ) is: G ( r , c , q ) = -1 indicates that the current grid point is in the unusable area at the front of the cargo hold or in the bottom gap area; G ( r , c , q ) = 0 indicates that the current grid is in an empty area; G ( r , c , q ) = 1 indicates that the current mesh is in the interlayer gap or horizontal gap region; G ( r , c , q ) = 2, indicating that the current grid point is in the cargo-occupied area; Initialize the state of all grid points in the 3D mesh: ; Initialize the corner point set P Starting corner of the cargo hold p 0 The starting corner point is used to place the bottom right corner of the first item.

[0022] S3, cargo preprocessing, including screening valid cargo, sorting and grouping cargo; Cargo pre-processing includes the following steps: Input the goods collection: ; No. i Each item is represented as: , i =1,2,…, n , n The total number of goods; in, s i For the first i A type label for each item, used to indicate the type of item; l i , w i , h i The first i The length, width, and height of each item (unit: millimeters); m i Indicates the first i Weight of each item (unit: kilograms); The set of valid goods is as follows: ; in, L , W , H These are the length, width, and height of the cargo hold, respectively. Goods are sorted according to the following priority: Cargo height priority > Cargo base area priority > Cargo length priority; Tall goods should be placed first, followed by goods with large base areas, and then long goods.

[0023] The goods are grouped by type, and the resulting collection of goods is: ; in, S This is a collection of labels for all goods types.

[0024] S4, Iterative Placement: The pre-processed goods are iteratively placed in the three-dimensional mesh space according to the constraints. During the iterative placement process, if the set of corner points... P If the item is not empty and there are still goods to be placed, perform the following steps: From the corner point set P Selecting corner points ,in, Iterate through all cargo types, select the cargo with the largest volume, and check if the selected cargo can be placed in a corner. ; Checking whether goods can be placed in a corner includes: a) Spatial inspection: The space occupied by the goods is: ; in, r i = l i / 10, c i = w i / 10, q i = h i / 10; r i , c i , q i The length of the current cargo l i ,Width w i ,high h i Number of grid cells occupied; The inspection conditions are: ; b) Stability check: like q = g f If it is stable, then check the support layer below the cargo: ; Where II is the indicator function; c) Placement location validity check, including: Placement conflict detection: ; Check if there are any goods on the left side of the placement location: ; If the space occupied by the goods on the left front overlaps with the space occupied by the current goods, it cannot be placed; if there is no overlap, it is determined whether the length of the goods protruding backward in the direction of length on the left front exceeds 20% of the length of the current goods (the specific value can be flexibly adjusted according to the actual situation). If it does not exceed 20%, it can be placed; the purpose is to ensure that the clamp can be smoothly withdrawn from the left side of the goods; in this embodiment, the clamp extends from the bottom left side of the goods to clamp the goods.

[0025] Check if there is any goods to the right of the placement location, and whether the length of the goods to the right is greater than 90% of the length of the current goods: ; ; in, This indicates the column index of the first detected item on the right. The purpose of this inspection step is to ensure that the clamp can be removed from the left side of the goods when placing the next column of goods.

[0026] Check if the height of the goods on the right is higher than 80% of the height of the current goods: ; Check if the height of the adjacent item on the right is greater than 80% of the height of the current item: ; The purpose of this inspection step is to ensure that the clamp can smoothly exit from the left side of the goods when placing the next layer of goods.

[0027] d) Weight check: ; in, M The total weight of the cargo already placed in the cargo hold. m i The current weight of the goods. M max This is the maximum load capacity of the cargo hold.

[0028] If possible, update the grid state and corner point set. P Then continue to select new corner points for placement; if not, select goods with a lower priority according to the order of goods priority, until the selected goods can be placed at the corner point.

[0029] If the selected goods can be placed at a corner point, then: Update the grid status as follows: ; Set horizontal gap: ; Updated total weight: M = M + m i ; Record placement location: ; p i Let be the coordinates of the geometric center of the i-th item in the grid; Update the corner point collection: ; Each corner point must meet the following conditions: .

[0030] S5, after iterative placement, perform symmetry adjustments on the goods: Calculate the column coordinates of the leftmost and rightmost cargo in the cargo hold: ; in, c min , c max These are the column coordinates of the leftmost and rightmost cargo in the cargo hold, respectively. Q A collection of goods that have already been placed; Get the width of the leftmost and rightmost cargo in the cargo hold: ; in, w min , w max These are the widths of the cargo on the far left and far right of the cargo hold, respectively. Calculate left and right space: ; in, s left This refers to the distance between the leftmost cargo and the left side panel of the cargo hold. s right The distance between the rightmost cargo and the right side panel of the cargo hold; Calculate the offset: ; If b ≥ 0, then adjust the coordinates: .

[0031] S6, coordinate transformation, converts the grid coordinates of the placed cargo into cargo hold space coordinates.

[0032] The coordinate transformation formula is as follows: ; in, Let be the origin of the cargo hold spatial coordinate system. Z The positive direction of the axis points towards the ground; Indicates the first i The coordinates of the bottom center of a cargo in the cargo hold space coordinate system; the above formula is used to convert the coordinates of the geometric center of the cargo in the grid coordinate system into the coordinates of the bottom center of the cargo in the cargo hold space coordinate system, which facilitates subsequent placement.

[0033] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A three-dimensional packing planning method based on dynamic mesh, characterized in that, Includes the following steps: Define the constraints for cargo loading; Discretize the cargo hold space into a three-dimensional mesh and initialize the three-dimensional mesh; Cargo preprocessing includes screening valid cargo, sorting and grouping cargo; Iterative placement involves iteratively placing the pre-processed goods within a three-dimensional mesh space according to constraints. Coordinate transformation converts the grid coordinates of the placed cargo into cargo hold space coordinates.

2. The three-dimensional packing planning method based on dynamic mesh as described in claim 1, characterized in that, The constraints include: 1) Bottom clearance: The clearance reserved between the bottom of the cargo hold and the first layer of cargo. g f ; 2) Interlayer gap: A vertical gap is reserved between adjacent goods on upper and lower layers. g l ; 3) Horizontal clearance: A horizontal clearance is reserved between adjacent goods on the same floor. g b ; 4) Unusable area at the front: An unusable area is reserved at the front of the cargo hold. L h × W × H ,in W , H These are the width and height of the cargo hold, respectively. L h To reserve the length of unusable areas; 5) Cargo may extend beyond the rear of the cargo hold, provided that the length of the extended portion is proportional to the total length of the cargo. α ; 6) The order of placing cargo in the cargo hold is from bottom to top, from front to back, and from right to left.

3. The three-dimensional packing planning method based on dynamic mesh as described in claim 2, characterized in that, Discretize the cargo hold space into a three-dimensional mesh. The grid cell size is 10×10×10, and the dimensions of the 3D grid are: ， ， ； in, L , W , H These are the length, width, and height of the cargo hold, respectively. Define the origin of the 3D mesh coordinate system as the bottom left corner mesh point; Define grid points in a 3D mesh ( r , c , q The state of ) is: G ( r , c , q ) = -1 indicates that the current grid point is in the front unavailable area or the bottom gap area; G ( r , c , q ) = 0 indicates that the current grid is in an empty area; G ( r , c , q ) = 1 indicates that the current mesh is in the interlayer gap or horizontal gap region; G ( r , c , q ) = 2, indicating that the current grid point is in the cargo-occupied area; Initialize the state of all grid points in the 3D mesh: ； Initialize the corner point set P Starting corner of the cargo hold p 0 The starting corner point is used to place the bottom right corner of the first item.

4. The three-dimensional packing planning method based on dynamic mesh as described in claim 3, characterized in that, Cargo pre-processing includes the following steps: Input the goods collection: ; No. i Each item is represented as: , i =1,2,…, n , n The total number of goods; in, s i For the first i A type label for each item, used to indicate the type of item; l i , w i , h i The first i The length, width, and height of each item; m i Indicates the first i The weight of each item; The set of valid goods is as follows: ； in, L , W , H These are the length, width, and height of the cargo hold, respectively. Goods are sorted according to the following priority: Cargo height priority > Cargo base area priority > Cargo length priority; The goods are grouped by type, and the resulting collection of goods is: ； in, S This is a collection of labels for all goods types.

5. The three-dimensional packing planning method based on dynamic mesh as described in claim 4, characterized in that, During the iterative placement process, if the set of corner points... P If the item is not empty and there are still goods to be placed, perform the following steps: From the corner point set P Selecting corner points ,in, Iterate through all cargo types, select the cargo with the largest volume, and check if the selected cargo can be placed in a corner. ; If possible, update the grid state and corner point set. P Then continue to select new corner points for placement; if not, select goods with a lower priority according to the order of goods priority, until the selected goods can be placed at the corner point.

6. The three-dimensional packing planning method based on dynamic mesh as described in claim 5, characterized in that, Checking whether goods can be placed in a corner includes: a) Spatial inspection: The space occupied by the goods is: ; in, r i = l i / 10, c i = w i / 10, q i = h i / 10; r i , c i , q i The length of the current cargo l i ,Width w i ,high h i Number of grid cells occupied; The inspection conditions are: ； b) Stability check: like q = g f If it is stable, then check the support layer below the cargo: ； Where II is the indicator function; c) Placement location validity check, including: Placement conflict detection: ； Check if there are any goods on the left side of the placement location: ； Check if there is any goods to the right of the placement location, and whether the length of the goods to the right is greater than 90% of the length of the current goods: ； ； in, This indicates the column index of the first detected item on the right. Check if the height of the goods on the right is higher than 80% of the height of the current goods: ； Check if the height of the adjacent item on the right is greater than 80% of the height of the current item: ； d) Weight check: ； in, M The total weight of the cargo already placed in the cargo hold. m i The current weight of the goods. M max This is the maximum load capacity of the cargo hold.

7. The three-dimensional packing planning method based on dynamic mesh as described in claim 6, characterized in that, If the selected goods can be placed at a corner point, then: Update the grid status as follows: ； Set horizontal gap: ； renew gross weight: M = M + m i ; Record placement location: ； p i Let be the coordinates of the geometric center of the i-th item in the grid; Update the corner point collection: ； Each corner point must meet the following conditions: 。 8. The three-dimensional packing planning method based on dynamic mesh as described in claim 7, characterized in that, After iterative placement, the goods are adjusted for symmetry: Calculate the column coordinates of the leftmost and rightmost cargo in the cargo hold: ； in, c min , c max These are the column coordinates of the leftmost and rightmost cargo in the cargo hold, respectively. Q A collection of goods that have already been placed; Get the width of the leftmost and rightmost cargo in the cargo hold: ； in, w min , w max These are the widths of the cargo on the far left and far right of the cargo hold, respectively. Calculate left and right space: ； in, s left This refers to the distance between the leftmost cargo and the left side panel of the cargo hold. s right The distance between the rightmost cargo and the right side panel of the cargo hold; Calculate the offset: ； If b ≥ 0, then adjust the coordinates: 。 9. The three-dimensional packing planning method based on dynamic mesh as described in claim 8, characterized in that, The coordinate transformation formula is as follows: ； in, Let be the origin of the cargo hold spatial coordinate system. Z The positive direction of the axis points towards the ground; Indicates the first i The coordinates of the bottom center of each cargo within the cargo hold spatial coordinate system.

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