Package single-piece separation control method and system of single-piece separation device

Abstract

The invention provides a parcel single-piece separation control method and system of a single-piece separation device, the single-piece separation device comprises a plurality of parallel conveying belts, and the conveying speeds of the parallel conveying belts are the same or different. Comprising the following steps that S1, position coordinates of packages on a single-piece separation device and the corresponding package conveying speed are obtained; s2, according to the position coordinates of the parcels and the parcel conveying speed, the distance between the parcels and an outlet of a single-piece separation device in the conveying direction is determined, and the priority processing levels of the parcels are sequenced according to the principle that the closer the distance is, the higher the priority processing level is; s3, the processing sequence of the packages is determined according to the priority processing levels, the target conveying speed of each package is determined according to a separation distance threshold value, and the separation distance threshold value is the preset minimum distance between every two adjacent packages; and the running speed of the conveyor belt is determined according to the conveying speeds corresponding to all the packages on each conveyor belt.

Description

Technical Field

[0001] The present invention relates to the technical field of logistics sorting, and in particular to a package single-piece separation control method and system of a single-piece separation device. Background Art

[0002] With the booming development of e-commerce, global express parcel volume has seen rapid annual growth exceeding 20%. In major e-commerce markets like China, the average daily parcel processing volume has exceeded 100 million pieces. In modern logistics sorting systems, the loading process of parcels from containers to sorting machines is the front-end input link, and its processing efficiency directly affects the throughput of the entire sorting system.

[0003] Currently, this front-end link still relies heavily on manual operations to complete the destacking and individual separation of packages, which has many limitations: manual processing speed is limited, making it difficult to meet the efficient sorting needs of large-scale packages; manual operations are less consistent, and fatigue, operational differences, and other factors can easily lead to unstable package separation spacing, affecting the normal operation of subsequent sorting equipment; in addition, labor costs increase significantly with the growth of package volume, further squeezing the profit margins of logistics companies.

[0004] Existing automated de-stacking and piece separation technologies suffer from issues such as insufficient accuracy in package location detection, inaccurate speed calculation (especially when packages cover multiple conveyor belt sections), delayed position prediction, lack of tracking for packages leaving the separation area, and inefficient handling of abnormal situations (such as stacked or stuck packages). These issues result in poor piece separation and the inability to achieve single-sequence output with preset or dynamic spacing, severely restricting the overall efficiency of the logistics sorting system. Summary of the Invention

[0005] In response to the shortcomings of the existing technology, the present invention proposes a package single-piece separation control method and system for a single-piece separation device to solve the technical problems in the existing technology that the single-piece separation effect is poor, the single sequence output with preset spacing or dynamic spacing cannot be achieved, and the overall efficiency of the logistics sorting system is seriously restricted.

[0006] To solve the above technical problems, in a first aspect, the present invention provides a method for controlling the separation of individual packages of a single-package separation device, wherein the single-package separation device includes a plurality of parallel conveyor belts, and the conveying speeds of the plurality of parallel conveyor belts are the same or different, comprising the following steps:

[0007] S1. Obtain the position coordinates of the package on the single-piece separation device and the corresponding package conveying speed;

[0008] S2. Determining the distance of the parcel from the exit of the single-piece separation device in the conveying direction based on the position coordinates of the parcel and the parcel conveying speed, and sorting the parcels by priority based on the principle that the closer the distance, the higher the priority;

[0009] S3. Determine the processing order of the packages based on the priority processing level, determine the target conveying speed of each package based on the separation distance threshold, wherein the separation distance threshold is a preset minimum distance that should be maintained between two adjacent packages; and determine the operating speed of the conveyor belt based on the conveying speed corresponding to all packages on each section of the conveyor belt.

[0010] Preferably, the S1 specifically includes:

[0011] S11. Acquire an image of each conveyor belt on the single-piece separation device, perform package position detection on the image based on a trained position detection model, determine the initial position coordinates of each package, and determine an initial package conveying speed based on the initial position coordinates;

[0012] S12. Determine the time difference between acquiring the image and determining the initial position coordinates, the average processing time of the position detection model, and the control delay time of the single-piece separation device; determine a delay offset based on the time difference, the average processing time, and the control delay time; determine a position compensation offset according to the initial package conveying speed and the delay offset; and determine a corrected position coordinate after the offset is compensated based on the position compensation offset and the initial position coordinates.

[0013] Preferably, in S12, the delay offset is:

[0014] D x_offset =V last *(T handle -T frame +T avgDelay +T plcDelay )

[0015] Among them, D x_offset is the delay offset of package x, T handle The time to obtain the initial position coordinates determined by the position detection model, T frame is the time to acquire the image, T avgDelay is the average processing time of the location detection model, T plcDelay To control the delay time, V last is the initial package delivery speed;

[0016] The position coordinates after compensation offset are determined as:

[0017] D x_new =D x +Dx_offset

[0018] Among them, D x_new To compensate for the offset, D x The initial position coordinate of the package x.

[0019] Preferably, in S11, determining the initial package delivery speed according to the initial position coordinates specifically includes:

[0020] If the package is determined to cover only a single section of the conveyor belt based on the initial position coordinates, the package speed is consistent with the operating speed of the corresponding conveyor belt;

[0021] If the package covers multiple conveyor belt sections according to the initial position coordinates, then the area value of the package on each conveyor belt is obtained, and the center of mass speed of the package is determined based on the area value of the package on each conveyor belt and the operating speed of the corresponding conveyor belt, and the center of mass speed is used as the initial package conveyance speed;

[0022] V last =(V b1 *A1+V bi *A n ,…,+V bn *A n ) / (A1+…+A n )

[0023] Among them, V last is the velocity of the center of mass, n represents the number of conveyor belts covered by a single package, V bi is the running speed of the conveyor belt section i, 1≤i≤n, A n The area covered by a single package on the nth conveyor belt.

[0024] Preferably, in S3, determining the processing order of the packages according to the priority processing level and determining the target transmission speed of each package according to the separation distance threshold specifically includes:

[0025] For the parcel with the highest priority level, if it is determined that there is no parcel ahead in the conveying direction, or there is no parcel within the separation distance threshold range ahead along the conveying direction, the parcel with the highest priority level will be set to be conveyed at the highest speed;

[0026] For packages of the other priority levels except the highest priority level, if it is determined that there is no package within the front separation distance threshold range along the conveying direction, it is set to be conveyed at the highest speed.

[0027] Preferably, in S3, determining the processing order of the packages according to the priority processing level and determining the target transmission speed of each package according to the separation distance threshold specifically includes:

[0028] For the highest priority parcel, if it is determined that there is a parcel ahead along the conveying direction and the actual distance is less than the separation distance threshold, the parcel conveying speed is determined as:

[0029]

[0030] In the above formula, D toExit The distance between the highest priority parcel and the exit of the single piece separation device, D iLeft is the remaining draw length, V out is the speed of the single-piece outer conveyor belt connected to the outlet of the single-piece separation device; wherein, the remaining pulling distance = separation distance threshold - actual distance.

[0031] Preferably, in S3, determining the processing order of the packages according to the priority processing level and determining the target transmission speed of each package according to the separation distance threshold specifically includes:

[0032] For packages of other priority levels except the highest priority level, if it is determined that there is a package ahead along the conveying direction and the actual distance is less than the separation distance threshold, the conveying speed of the package is determined to be:

[0033]

[0034] Among them, D lastToExit V is the distance between the previous package and the exit of the single-piece separation device, n+1 is the delivery speed of the previous package, D i is the separation distance threshold, and β is a preset fixed value related to the conveyor belt and package type.

[0035] Preferably, in S3, the running speed of the conveyor belt is determined according to the conveying speed corresponding to all packages on each section of the conveyor belt, specifically including:

[0036] If there is only one package on a conveyor belt section, make sure the conveyor belt runs at the same speed as the target package delivery speed;

[0037] If there are multiple packages on a conveyor belt section, determine the coverage area of ​​each package on the conveyor belt and determine the first ratio r of the coverage area to the total area of ​​the conveyor belt. A , determine the first positive correlation coefficient W according to the first proportion A ; Determine the second ratio r of the coverage area to the package area S , determine the second normal relationship number W according to the second proportion S ; Sort by priority level to determine the priority weight coefficient W of each package on the conveyor belt P ;

[0038] Determine the speed limit coefficient K based on the maximum and minimum operating speeds of the conveyor belt lim ;

[0039] Determining an empirical weight of the first positive correlation coefficient, the second positive correlation coefficient, and the priority weight coefficient;

[0040] A weighted average is performed on all packages based on the speed limit coefficient, the first positive correlation coefficient, the second positive correlation coefficient, the priority weight coefficient, and the corresponding empirical weight:

[0041] V belt =K lim ×∑(V n ×(W A ×β1+W S ×β2+W P ×β3))

[0042] In the above formula, V belt is the running speed of the conveyor belt, n is the number of packages on the same section of the conveyor belt, β1, β2, and β3 are the first positive correlation coefficient, the second positive correlation coefficient, the priority weight coefficient, and the corresponding empirical weight, respectively.

[0043] In a second aspect, the present invention provides a parcel single piece separation control system for a single piece separation device, wherein the single piece separation device includes a plurality of parallel conveyor belts, wherein the conveying speeds of the plurality of parallel conveyor belts are the same or different, and comprises:

[0044] The package position and speed determination module is used to obtain the position coordinates of the package on the single-piece separation device and the corresponding package conveying speed;

[0045] a priority processing level sorting module, configured to determine the distance of the parcel from the exit of the single piece separation device in the conveying direction based on the position coordinates of the parcel and the parcel conveying speed, and sort the parcels by priority level based on the principle that the closer the distance, the higher the priority level;

[0046] The conveyor belt speed calculation module determines the processing order of the packages based on the priority processing level, and determines the target conveying speed of each package based on the separation distance threshold, where the separation distance threshold is a preset minimum distance that should be maintained between two adjacent packages; and determines the conveyor belt operating speed based on the conveying speed corresponding to all packages on each conveyor belt section.

[0047] Compared with the prior art, the present invention has the following advantages:

[0048] 1. Through YOLOv5 real-time detection and dynamic speed control, the system automatically processes packages from "unordered" to "single-sequence, orderly output," breaking through the speed bottleneck of manual operations (the background technology mentioned the daily demand for hundreds of millions of packages) and significantly increasing the processing volume per unit time. Priority-based speed scheduling (packages near the exit are given priority) and conveyor belt speed prediction (predicting covered conveyor belts and adjusting speeds in advance) reduce package waiting or congestion time and improve the flow efficiency of the single-exit area.

[0049] 2. The position correction formula eliminates position deviations caused by delays in image acquisition and inference. Combined with the centroid speed calculation (when covering multiple conveyor belt sections), it ensures the accuracy of package position and speed detection, providing an accurate data basis for spacing control. The dynamic adaptation of the preset separation spacing and the remaining pull distance keeps the spacing error between adjacent packages within a reasonable range, avoiding overlap and congestion, and ensuring the stability of subsequent sorting links.

[0050] 3. Special handling of abnormal situations such as overlapping and sticking reduces system downtime or efficiency drops caused by abnormalities, and improves the adaptability to complex package shapes; it replaces the de-stacking and separation operations in the traditional manual loading process, reduces labor costs and errors caused by manual fatigue, and realizes full automation of the logistics sorting front end, which meets the scale requirements under the rapid development of e-commerce. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0052] Figure 1 Schematic diagram of the structure of the automatic parcel separation system according to an embodiment of the present invention;

[0053] Figure 2 Schematic diagram of a method for controlling the separation of individual packages by a single-package separation device according to an embodiment of the present invention;

[0054] Figure 3 Schematic diagram of a package single piece separation control system of a single piece separation device according to an embodiment of the present invention. DETAILED DESCRIPTION

[0055] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0056] In the description of the present invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings and are intended solely to facilitate and simplify the description of the present invention. They are not intended to indicate or imply that the devices or components referred to must have, be constructed, or operate in a specific orientation, and therefore should not be construed as limiting the present invention. Furthermore, the terms "first," "second," "third," and "fourth," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0057] In the description of the present invention, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood in a broad sense. For example, they may refer to fixed, detachable, or integral connections; mechanical or electrical connections; direct or indirect connections through an intermediate medium; and internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on the specific circumstances.

[0058] See also Figures 1 to 3 The embodiment of the present invention discloses a method for controlling the separation of individual packages of a single-piece separation device, which is applied to an automatic package separation system, such as Figure 2 As shown in , the automatic parcel separation system includes an inlet section, a de-duplication section (corresponding to a de-duplication device), a single separation section (single separation device), and an outlet section. The de-duplication section is used to separate stacked parcels, that is, to separate the stacked parcels into parcels that are normally placed flat on the automatic parcel feeding line. The single separation device includes multiple parallel conveyor belts, and the conveying speeds of the multiple parallel conveyor belts are the same or different. The system includes the following steps:

[0059] S1. Obtaining the position coordinates of the package on the single-piece separation device and the corresponding package conveying speed; specifically including:

[0060] S11. Acquire an image of each conveyor belt on the single-piece separation device, perform package position detection on the image based on a trained position detection model, determine the initial position coordinates of each package, and determine an initial package conveying speed based on the initial position coordinates;

[0061] Specifically, by deploying target cameras (such as industrial area array cameras with a resolution of not less than 1920×1080 and a frame rate of 30 frames per second) at key positions of the single-piece separation device, the camera installation height and angle must be pre-calibrated to ensure that the image can completely cover the entire conveyor belt area of ​​the single-piece separation device (such as the physical range of a 4×6 matrix conveyor belt), and that the direction of movement of the conveyor belt in the image is parallel to the x-axis of the pixel coordinate system (to facilitate subsequent coordinate conversion). Images of each section of the conveyor belt are collected in real time to ensure that the operating area of ​​all conveyor belts is covered; a pre-trained YOLOv5 model is used as a position detection model. This model is trained with a large number of package image samples and can quickly identify the outline of the package in the image and select the position, outputting the initial position coordinates (such as the x-axis and y-axis coordinates) of each package in the image coordinate system, that is, the initial position information; the initial position information only reflects the position of the package in the image at the moment the camera is shot, and does not take into account factors such as conveyor belt operation delay, and requires subsequent compensation and correction.

[0062] Furthermore, the model outputs the bounding box coordinates (the visual algorithm in this embodiment infers the minimum enclosing rectangle of the package, and outputs the coordinates of 4 vertices for each package, starting from the leftmost vertex on the X-axis and sorted clockwise; the output coordinates are pixel coordinates (unit px), which need to be converted according to the ratio configured during debugging (pixels / actual distance) to obtain world coordinates (unit mm)). The initial position coordinates take the entrance end of the separation device as the origin, the direction of movement along the conveyor belt as the x-axis, and the direction perpendicular to the movement as the y-axis. The front end point of the package bounding box in the x-axis direction (the x value of the vertex on the leftmost end of the package) is taken as the core position coordinate (reflecting the real-time position of the package along the direction of movement).

[0063] Furthermore, if the package covers multiple conveyor belts according to the initial position coordinates, the area value of the package on each conveyor belt is obtained, and the center of mass speed of the package is determined based on the area value of the package on each conveyor belt and the running speed of the corresponding conveyor belt, and the center of mass speed is used as the initial package conveying speed;

[0064] V last =(V b1 *A1+V bi *A n ,…,+V bn *A n ) / (A1+…+A n )

[0065] Among them, V last is the velocity of the center of mass, n represents the number of conveyor belts covered by a single package, V bi is the running speed of the conveyor belt section i, 1≤i≤n, A n The area covered by a single package on the nth conveyor belt.

[0066] S12. Determine the time difference between acquiring the image and determining the initial position coordinates, the average processing time of the position detection model, and the control delay time of the single-piece separation device; determine a delay offset based on the time difference, the average processing time, and the control delay time; determine a position compensation offset according to the initial package conveying speed and the delay offset; and determine a corrected position coordinate after the offset is compensated based on the position compensation offset and the initial position coordinates.

[0067] Furthermore, the delay offset is:

[0068] D x_offset =V last *(T handle -T frame +T avgDelay +T plcDelay )

[0069] Among them, D x_offset is the delay offset of package x, T handle The time to obtain the initial position coordinates determined by the position detection model, T frame is the time to acquire the image, T avgDelay is the average processing time of the location detection model, T plcDelay To control the delay time, V last is the initial package delivery speed;

[0070] The position coordinates after compensation offset are determined as:

[0071] D x_new =D x +D x_offset

[0072] Among them, D x_new To compensate for the offset, D x The initial position coordinate of the package x.

[0073] Specifically, the time difference between acquiring the image and determining the initial position coordinates (T diff ): Refers to the camera image acquisition time (T frame , that is, the time when the image is generated, recorded by the camera timestamp) and the time when the position detection model outputs the initial position coordinates (T handle ), that is, the time when the system receives the coordinates, which is recorded by the host computer), the difference, that is, (T diff =T handle -T frame ). This time difference mainly includes model inference delay (the time it takes for YOLOv5 to process images) and data transmission delay.

[0074] Average processing time of the location detection model (T avgDelay): Refers to the average time taken by the location detection model from receiving an image to outputting coordinates for the last N times (e.g., the last 100 times), calculated using system log statistics:

[0075]

[0076] Control delay time of single piece separation device (T plcDelay ) refers to the delay time from the host computer of the single-piece separation device issuing a control command to the conveyor belt executing speed adjustment (determined by the PLC hardware and communication protocol, such as the typical delay of the EtherCAT protocol is 5-10ms), obtained through pre-calibration.

[0077] Furthermore, in S11, determining the initial package delivery speed according to the initial position coordinates specifically includes:

[0078] If the package is determined to cover only a single section of the conveyor belt based on the initial position coordinates, the package speed is consistent with the operating speed of the corresponding conveyor belt;

[0079] Specifically, in a single conveyor belt coverage scenario, if the physical coordinates of the package's bounding box only fall within the physical range of a single conveyor belt segment (e.g., a package's x-axis range is 1.2-1.5 meters, and it only covers the third conveyor belt segment, with a physical range of 1.0-1.6 meters), the initial conveying speed is equal to the current operating speed of that conveyor belt segment (feedback in real time by the PLC of the single-piece separation device, denoted as V b ).

[0080] S2. Determining the distance of the parcel from the exit of the single-piece separation device in the conveying direction based on the position coordinates of the parcel and the parcel conveying speed, and sorting the parcels by priority based on the principle that the closer the distance, the higher the priority;

[0081] Specifically, the new package location coordinates (corrected location coordinates) can be used to calculate the actual location covered by the package and the location to be covered. Through the dual dimensions of "real-time location + movement trend prediction", the "dynamic distance" of the package to the exit is calculated, achieving accurate sorting of "whoever arrives at the exit first gets priority". The core logic is:

[0082] Basic dimension: the current corrected position coordinate D x_new Reflects the real-time physical location of the package; Trend dimension: package delivery speed V last To reflect its movement trend, it is necessary to combine the speed after delay compensation to predict the future position;

[0083] Sorting basis: Comprehensively consider the "remaining distance from the real-time position to the exit" and the "arrival time under the movement trend" to ensure that the sorting is strictly consistent with the actual order of arrival at the exit.

[0084] Furthermore, assume that the coordinate of the exit of the single-piece separation device in the x-axis direction is Dexit (fixed value, such as the exit is located at x = 5.0m), and there are m packages in the single separation area (denoted as Obj1, Obj2, ..., Obj m ), the specific sorting steps are as follows:

[0085] Step 1: Calculate the "static remaining distance" of the package to the exit

[0086] The corrected real-time coordinates of each package are D x_new,i (i = 1 ~ m), then the static remaining distance (not considering speed, based only on the current position) is:

[0087] D static,i =D exit -D x_new,i

[0088] Example: If D exit =5.0m, package O bj1 D x_new,1 =3.2m, then D static,1 =1.8m; Package O bj2 D x_new,2 =3.5m, then D static,2 =1.5m→O bj2 The static distance is closer.

[0089] Step 2: Calculate the “dynamic arrival time” of the package to the exit combined with the package delivery speed V last,i (the center of mass speed or single conveyor belt speed determined in S1), calculate the theoretical arrival time of the package from the current location to the exit:

[0090]

[0091] Supplementary logic: If the package speed V last,i = 0 (if the package is not yet driven by the conveyor belt), then T arrive,i Set to the maximum value (considered as a "static package", the lowest priority). Example: O bj1 V last,1 =0.8m / s, then T arrive,1 =1.8 / 0.8=2.25s; O bj2 V last,2 =1.0m / s, then T arrive,2 =1.5 / 1.0=1.5s→O bj2 The arrival time is shorter.

[0092] Step 3: Prioritize using both dimensions. The sorting rule is based on the principle of "the shorter the dynamic arrival time, the higher the priority", while also being compatible with the special scenario of "the same static distance":

[0093] Basic sorting: by T arrive,i Sort from small to large, T arrive,i The smaller the value, the higher the priority.

[0094] Conflict handling: If two packages of T arrive,i If the difference is less than the threshold (such as ΔT≤0.1s, which can be set through on-site debugging), the “static remaining distance” D static,i , the shorter distance has higher priority; if they are still the same, compare the "package length" (calculated by bounding box, shorter packages are given priority to avoid long packages getting stuck).

[0095] Special adaptation of the sorting logic is required for scenarios such as packages covering multiple conveyor belts in the single-separation area, dynamic changes in conveyor belt speed, and abnormal packages (such as overlapped or stuck packages):

[0096] The center of mass velocity V of a package covered by multiple conveyor belts last It will change in real time with the conveyor belt speed adjustment (for example, a section of the conveyor belt slows down due to upstream congestion), and the sorting needs to be updated dynamically.

[0097] Implementation method: When each frame image is detected (30 frames / second), recalculate V last,i (According to the center of mass velocity formula of S1); Synchronously update T arrive,i and priority sorting to ensure that the sorting is adjusted in real time as the speed changes.

[0098] Some packages have left the single-exit conveyor belt and entered the virtual field of view after the exit (such as the area with x>5.0m). It is necessary to distinguish and sort the packages that are "on the conveyor belt" and "have left the conveyor belt".

[0099] For packages in the virtual field of view, the “distance to the exit” D static,i Set to a negative number (reached the exit), T arrive,i = 0 (arrived); when sorting, the parcels in the virtual field of view have higher priority than the parcels in the single-leaving area (parcels that have left the conveyor belt are prioritized to enter the sorting link).

[0100] For overlapping packages, if the overlap is serious (two packages overlap to a large extent, or completely overlap), such as IOU greater than 0.4 (can be set), it will be detected as a "single large package", and there will be errors in the calculation of its centroid speed and position, requiring special sorting; the "number of covered conveyor belts" of the overlapping packages is calculated according to the merged bounding box, and A in the centroid speed formula is n The combined area is marked as "abnormal package" and sent out directly to avoid affecting the overall efficiency.

[0101] If the overlap is light (two packages only partially overlap), such as IOU ≤ 0.4, the original speed strategy is used for separation. If separation is still not possible after a certain period of time (which can be set, such as 0.5s), the "quick delivery" logic will be triggered to avoid jams that affect overall efficiency.

[0102] Through the above steps of this embodiment, errors caused by sorting based solely on "current position" (e.g., a low-speed package may be positioned earlier, but a high-speed package actually arrives at the exit first) are avoided, ensuring that the sorting is consistent with the actual arrival order. Priority can be adjusted in real time based on changes in package and conveyor speed to adapt to complex logistics scenarios. Through conflict resolution (time difference threshold, package length verification) and exception adaptation (overlapping piece marking, rapid delivery), the system ensures sorting efficiency in extreme scenarios.

[0103] S3. Determine the processing order of the packages based on the priority processing level, determine the target conveying speed of each package based on the separation distance threshold, wherein the separation distance threshold is a preset minimum distance that should be maintained between two adjacent packages; and determine the operating speed of the conveyor belt based on the conveying speed corresponding to all packages on each section of the conveyor belt.

[0104] Furthermore, in S3, the processing order of the packages is determined according to the priority processing level, and the target transmission speed of each package is determined according to the separation distance threshold, which specifically includes:

[0105] For the highest priority parcel, if it is determined that there is no parcel ahead in the conveying direction, or there is no parcel within the separation distance threshold ahead along the conveying direction, the parcel with the highest priority will be set to be conveyed at the highest speed;

[0106] For packages of the other priority levels except the highest priority level, if it is determined that there is no package within the front separation distance threshold range along the conveying direction, it is set to be conveyed at the highest speed.

[0107] Specifically, the distance between the current package and the preceding package along the conveying direction is calculated by combining the real-time position coordinates of the package on the conveyor belt (the coordinates corrected in step S1, accurate to the millimeter level), as well as the length and layout information of the conveyor belt (for example, the conveyor belt is multi-sectioned, and the length, start and end coordinates of each section are pre-calibrated). For example, if the conveyor belt is conveyed along the x-axis, the current package position coordinates are x curr , the coordinate of the front package position is x front , spacing d = x front -x curr , when d ≥ separation distance threshold or x front When it does not exist (i.e. there is no package ahead), the condition is met.

[0108] The maximum speed is determined based on the hardware performance of the single-piece separation device, the characteristics of the package (such as the maximum load-bearing capacity and impact resistance of the package, as determined by extensive experimental testing of the safe maximum speed of different package types on the conveyor belt, and the establishment of a mapping table between package type and maximum speed), and the upper limit of the receiving speed of the downstream sorting equipment. The maximum speed for single separation is generally 1.5-2.2m / s, and the equipment that connects to the single separation is generally a narrow belt or a swing wheel automatic package feeder.

[0109] When the conditions for transmitting at the highest speed are met, it does not switch to the highest speed instantly, but adopts a linear acceleration strategy. In the speed calculation strategy of the package, the acceleration process of other packages will be kept as smooth as possible while ensuring that the package with the highest priority runs at the highest speed, so as to reduce the impact of sudden speed changes on the package's running status, such as rolling, slipping, etc. In addition to detecting the distance between adjacent packages in front, the distribution of multiple packages in front is also considered. All packages within a certain range in front of the transmission direction (such as 3 meters, covering multiple separation distance threshold lengths) are identified through the target detection algorithm, and the package position sequence [x1, x2, ..., x n ](x i is the position coordinate of the i-th package). Calculate the distance d between the current package and each package in front. i =x i -x curr , determine whether the distance between packages is less than the separation distance threshold. If so, further analysis is needed of the priority level and motion status (speed, acceleration) of these packages to provide a more comprehensive basis for subsequent speed adjustments. For example, if there are two packages ahead, the first package is 0.3 meters apart (less than the 0.5-meter threshold), but this package has a low priority level and is moving slowly. The current package's speed strategy can be appropriately adjusted. The second package is 0.6 meters apart (greater than the threshold), and a comprehensive assessment is needed to determine whether the overall spacing meets the requirements.

[0110] Furthermore, the separation distance threshold is not a fixed value, but can be adjusted dynamically according to the package flow and type. For some scenarios with limited processing capabilities, or scenarios where flow needs to be controlled, the real-time flow can be calculated by the number of packages passing through within a specified time. By comparing this real-time flow with the preset flow, if the flow is low, the separation distance is reduced. If the flow is high, the separation distance is increased. This method is used to achieve flow control and improve transmission efficiency. When the package type is fragile or overweight, the separation distance threshold is increased (such as adjusted to 0.8 meters) to ensure the safety of the package. The adjustment logic is implemented through a preset rule engine, which matches the corresponding threshold adjustment strategy based on the package flow, type and other data collected in real time.

[0111] Furthermore, in S3, the processing order of the packages is determined according to the priority processing level, and the target transmission speed of each package is determined according to the separation distance threshold, which specifically includes:

[0112] For the highest priority parcel, if it is determined that there is a parcel ahead along the conveying direction and the actual distance is less than the separation distance threshold, the parcel conveying speed is determined as:

[0113]

[0114] In the above formula, D toExit The distance between the highest priority parcel and the exit of the single piece separation device, D iLeft is the remaining draw length, V out is the speed of the single-piece outer conveyor belt connected to the outlet of the single-piece separation device; wherein, the remaining pulling distance = separation distance threshold - actual distance.

[0115] Specifically, the actual distance is obtained through visual detection. An industrial camera (e.g., resolution 1920×1080, frame rate 30fps) above the isolation area is used in combination with a target detection algorithm (YOLOv5 optimized version, adapted to package overlap and deformation scenarios) to calculate the distance D between the current package and the preceding package along the conveying direction in real time. real .

[0116] Separation distance threshold D th Dynamically adjustable: The separation spacing setting generally depends on the docking equipment. For example, for a 200-pitch narrow belt, the separation spacing must be above 200mm, and for a 300-pitch narrow belt, it must be above 300mm. If code reading is required, the setting depends on the code reading camera's requirements for package spacing (usually 300-500mm). If a weighing function is used, the setting also needs to be based on the length of the weighing belt.

[0117] The core idea behind formula V1 is to ensure that the distance between the current package and the preceding package just meets the separation threshold when the current package arrives at the exit. By dynamically reducing the speed based on the ratio of the current remaining distance to the exit to the required additional distance (remaining distance), the package arrives within the required time and distance to the exit.

[0118] The calculated V1 must be ≥ the minimum conveyor belt speed (e.g., 0.2 m / s to prevent package accumulation and equipment jamming). If the calculated V1 = 0.15 m / s, it is forcibly set to 0.2 m / s. At the same time, V1 must be ≤ the maximum conveyor belt speed (e.g., 1.8 m / s to prevent packages from exceeding the speed limit and causing the docking equipment to be unable to process them). If the calculated V1 = 1.9 m / s, it is forcibly set to 1.8 m / s.

[0119] Furthermore, in S3, the processing order of the packages is determined according to the priority processing level, and the target transmission speed of each package is determined according to the separation distance threshold, which specifically includes:

[0120] For packages of other priority levels except the highest priority level, if it is determined that there is a package ahead along the conveying direction and the actual distance is less than the separation distance threshold, the conveying speed of the package is determined to be:

[0121]

[0122] Among them, D lastToExit V is the distance between the previous package and the exit of the single-piece separation device, n+1 is the delivery speed of the previous package, D i is the separation distance threshold, and β is a preset fixed value related to the conveyor belt and package type.

[0123] Specifically, the above solution is used for the scenario where non-highest priority packages are in "front congestion (actual distance < separation threshold)". The essence is to make the distance between the current package and the previous package meet the separation threshold when reaching the exit. The remaining distance of the previous package, the distance threshold, and the adaptation coefficient are used to constrain the speed and ensure the distance coordination when multiple packages are congested. i Dynamic adjustment to adapt to different conveyor belts and package types (for example, when the friction coefficient of the conveyor belt decreases in winter, β is automatically increased by +0.1), improving the robustness of the system.

[0124] Furthermore, in S3, the running speed of the conveyor belt is determined according to the conveying speed corresponding to all packages on each section of the conveyor belt, specifically including:

[0125] If there is only one package on a conveyor belt section, make sure the conveyor belt runs at the same speed as the target package delivery speed;

[0126] If there are multiple packages on a conveyor belt section, determine the coverage area of ​​each package on the conveyor belt and determine the first ratio r of the coverage area to the total area of ​​the conveyor belt. A , determine the first positive correlation coefficient W according to the first proportion A ; Determine the second ratio r of the coverage area to the package area S , determine the second normal relationship number W according to the second proportion S ; Sort by priority level to determine the priority weight coefficient W of each package on the conveyor belt P ;

[0127] Specifically, calculate the area A that each package covers on the conveyor belt b , obtained by mapping the bounding box detected by the image to the physical coordinates of the conveyor belt, and its total area of ​​the conveyor belt (A bel, fixed value, such as the ratio of the area of ​​a single conveyor belt to L×W):

[0128] r A =A b / A belt

[0129] This ratio reflects the "physical occupancy intensity" of the package on the conveyor belt. The higher the ratio, the greater the impact of the package on the conveyor belt speed. The weight W A With r A Positive correlation (such as W A =r A / ∑r A ), ensure that all packages W A The sum is 1).

[0130] Calculate the area of ​​the belt covered by each package (A b ) accounts for its own total area (A obj , the ratio of the physical area of ​​the complete bounding box):

[0131] r S =A b / A obj

[0132] This ratio reflects the degree to which the package "depends on the belt for transmission". If only a small part of the package covers the belt (such as only the edge of the belt), its dependence on the belt speed is low; if most of the area covers the belt, the dependence is higher. Weight W S With r S Positive correlation (such as W S =r S / ∑r S ).

[0133] Based on the sorting results of step S3, a priority coefficient is assigned to each package (e.g., the highest priority package has a coefficient of 1.2, the second highest is 1.0, and the lowest priority is 0.8), reflecting the "processing urgency" of the package. The higher the priority of the package, the more significant the impact of its speed demand on the belt, and the weight W P Directly use the priority coefficient normalization process (such as W P =P i / ∑P i , P i is the priority coefficient of the package).

[0134] Determine the speed limit coefficient K based on the maximum and minimum operating speeds of the conveyor belt lim ; Combined with the mechanical properties of the belt (such as the maximum speed V max , minimum speed V min ), constrain the weighted average result: if the calculated speed exceeds V max , then Vmin As the upper limit; if it is lower than V max , then V min This is the lower limit (to prevent subsequent objects from piling up due to the belt speed being too low).

[0135] Determining an empirical weight of the first positive correlation coefficient, the second positive correlation coefficient, and the priority weight coefficient;

[0136] A weighted average is performed on all packages based on the speed limit coefficient, the first positive correlation coefficient, the second positive correlation coefficient, the priority weight coefficient, and the corresponding empirical weight:

[0137] V belt =K lim ×∑(V n ×(W A ×β1+W S ×β2+W P ×β3))

[0138] In the above formula, V belt is the running speed of the conveyor belt, n is the number of packages on the same section of the conveyor belt, β1, β2, and β3 are the first positive correlation coefficient, the second positive correlation coefficient, the priority weight coefficient, and the corresponding empirical weight, respectively.

[0139] Specifically, β1, β2, and β3 can be 0.4, 0.3, and 0.3, respectively (which can be adjusted according to actual scenarios).

[0140] Furthermore, the posture of the individually output package (suitable for large package separation scenarios) can be adjusted (for example, adjusted to the short side facing forward). Based on the package coordinates obtained by the visual recognition algorithm, the package's tilt angle θ (the angle between the short side and the Y-axis) can be calculated. When the angle θ = 0°, the package posture has been adjusted to the short side leading. The package can be rotated by using the speed difference between the upper and lower parts of the belt in the X-axis direction to achieve the effect of posture adjustment.

[0141] The specific speed value V of the package can be calculated from S3. The distance of the package from the exit can be obtained by vision, and the time T required for the package to leave the unit can be calculated. The angular velocity ω required for the package to rotate can be calculated based on the angle θ and the time T (ω=θ / T). Based on the length W of the short side of the package, the speed difference ΔV=ω×W can be calculated. Then the belt speed on both sides can be corrected to V new =V±ΔV / 2. In a second aspect, the present invention provides a control system for separating individual packages of an individual package separation device, wherein the individual package separation device comprises a plurality of parallel conveyor belts, wherein the conveying speeds of the plurality of parallel conveyor belts are the same or different. Based on the control method for separating individual packages of the individual package separation device described in the above embodiment, as Figure 3As shown in , the system includes:

[0142] The package position and speed determination module 310 is used to obtain the position coordinates of the package on the single piece separation device and the corresponding package conveying speed;

[0143] a priority sorting module 320 for determining the distance of the parcel from the exit of the single-piece separation device in the conveying direction based on the parcel's location coordinates and the parcel conveying speed, and sorting the parcels by priority based on the principle that the closer the distance, the higher the priority;

[0144] The conveyor belt speed calculation module 330 is used to determine the processing order of the packages based on the priority processing level, determine the target conveying speed of each package based on the separation distance threshold, wherein the separation distance threshold is a preset minimum distance that should be maintained between two adjacent packages; and determine the conveyor belt operating speed based on the conveying speed corresponding to all packages on each conveyor belt section.

[0145] 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 in the scope of protection of the present invention.

Claims

1. A method for controlling the separation of individual packages of a package separation device, wherein the package separation device comprises a plurality of parallel conveyor belts, wherein the conveying speeds of the plurality of parallel conveyor belts are the same or different, and wherein: The following steps are involved: S1. Obtain the position coordinates of the package on the single-piece separation device and the corresponding package conveying speed; S2. Determining the distance of the parcel from the exit of the single-piece separation device in the conveying direction based on the position coordinates of the parcel and the parcel conveying speed, and sorting the parcels by priority based on the principle that the closer the distance, the higher the priority; S3. Determine the processing order of the packages based on the priority processing level, determine the target conveying speed of each package based on the separation distance threshold, wherein the separation distance threshold is a preset minimum distance that should be maintained between two adjacent packages; and determine the operating speed of the conveyor belt based on the conveying speed corresponding to all packages on each section of the conveyor belt.

2. The method for controlling the separation of individual packages of a single-piece separation device according to claim 1, characterized in that: Said S1 specifically includes: S11. Acquire an image of each conveyor belt on the single-piece separation device, perform package position detection on the image based on a trained position detection model, determine the initial position coordinates of each package, and determine an initial package conveying speed based on the initial position coordinates; S12. Determine the time difference between acquiring the image and determining the initial position coordinates, the average processing time of the position detection model, and the control delay time of the single-piece separation device; determine a delay offset based on the time difference, the average processing time, and the control delay time; determine a position compensation offset according to the initial package conveying speed and the delay offset; and determine a corrected position coordinate after the offset is compensated based on the position compensation offset and the initial position coordinates.

3. The method for controlling the separation of individual packages of a single package separation device according to claim 2, characterized in that: In S12, the delay offset is: D x_offset =V last *(T handle -T frame +T avgDelay +T plcDelay ) Among them, D x_offset is the delay offset of package x, T handle The time to obtain the initial position coordinates determined by the position detection model, T frame is the time to acquire the image, T avgDelay is the average processing time of the location detection model, T plcDelay To control the delay time, V last is the initial package delivery speed; The position coordinates after compensation offset are determined as: D x_new =D x +D x_offset Among them, D x_new To compensate for the offset, D x The initial position coordinate of the package x.

4. The method for controlling the separation of individual packages of a single-piece separation device according to claim 2, characterized in that: In S11, determining the initial package delivery speed according to the initial position coordinates specifically includes: If the package is determined to cover only a single section of the conveyor belt based on the initial position coordinates, the package speed is consistent with the operating speed of the corresponding conveyor belt; If the package covers multiple conveyor belt sections according to the initial position coordinates, then the area value of the package on each conveyor belt is obtained, and the center of mass speed of the package is determined based on the area value of the package on each conveyor belt and the operating speed of the corresponding conveyor belt, and the center of mass speed is used as the initial package conveyance speed; In last =(V b1 *A1+V bi *A n ,…,+V bn *A n ) / (A1+…+A n ) Among them, V last is the velocity of the center of mass, n represents the number of conveyor belts covered by a single package, V bi is the running speed of the conveyor belt section i, 1≤i≤n, A n The area covered by a single package on the nth conveyor belt.

5. The method for controlling the separation of individual packages of a single-piece separation device according to claim 1, characterized in that: In S3, the processing order of the packages is determined according to the priority processing level, and the target transmission speed of each package is determined according to the separation distance threshold, which specifically includes: For the highest priority parcel, if it is determined that there is no parcel ahead in the conveying direction, or there is no parcel within the separation distance threshold ahead along the conveying direction, the parcel with the highest priority will be set to be conveyed at the highest speed; For packages of the other priority levels except the highest priority level, if it is determined that there is no package within the front separation distance threshold range along the conveying direction, it is set to be conveyed at the highest speed.

6. The method for controlling the separation of individual packages of a single package separation device according to claim 1, characterized in that: In S3, the processing order of the packages is determined according to the priority processing level, and the target transmission speed of each package is determined according to the separation distance threshold, which specifically includes: For the highest priority parcel, if it is determined that there is a parcel ahead along the conveying direction and the actual distance is less than the separation distance threshold, the parcel conveying speed is determined as: In the above formula, D toExit The distance between the highest priority parcel and the exit of the single piece separation device, D iLeft is the remaining draw length, V out is the speed of the single-piece outer conveyor belt connected to the outlet of the single-piece separation device; wherein, the remaining pulling distance = separation distance threshold - actual distance.

7. The method for controlling the separation of individual packages of a single-piece separation device according to claim 1, characterized in that: In S3, the processing order of the packages is determined according to the priority processing level, and the target transmission speed of each package is determined according to the separation distance threshold, which specifically includes: For packages of other priority levels except the highest priority level, if it is determined that there is a package ahead along the conveying direction and the actual distance is less than the separation distance threshold, the conveying speed of the package is determined to be: Among them, D lastToExit V is the distance between the previous package and the exit of the single-piece separation device, n+1 is the delivery speed of the previous package, D i is the separation distance threshold, and β is a preset fixed value related to the conveyor belt and package type.

8. The method for controlling the separation of individual packages of a single package separation device according to claim 1, characterized in that: In S3, the running speed of the conveyor belt is determined according to the conveying speed corresponding to all packages on each section of the conveyor belt, specifically including: If there is only one package on a conveyor belt section, make sure the conveyor belt runs at the same speed as the target package delivery speed; If there are multiple packages on a conveyor belt section, determine the coverage area of ​​each package on the conveyor belt and determine the first ratio r of the coverage area to the total area of ​​the conveyor belt. A , determine the first positive correlation coefficient W according to the first proportion A ; Determine the second ratio r of the coverage area to the package area S , determine the second normal relationship number W according to the second proportion S ; Sort by priority level to determine the priority weight coefficient W of each package on the conveyor belt P ; Determine the speed limit coefficient K based on the maximum and minimum operating speeds of the conveyor belt lim ; Determining an empirical weight of the first positive correlation coefficient, the second positive correlation coefficient, and the priority weight coefficient; A weighted average is performed on all packages based on the speed limit coefficient, the first positive correlation coefficient, the second positive correlation coefficient, the priority weight coefficient, and the corresponding empirical weight: V belt =K lim ×∑(V n ×(W A ×β1+W S ×β2+W P ×β3)) In the above formula, V belt is the running speed of the conveyor belt, n is the number of packages on the same section of the conveyor belt, β1, β2, and β3 are the first positive correlation coefficient, the second positive correlation coefficient, the priority weight coefficient, and the corresponding empirical weight, respectively.

9. A package separation control system for a single piece separation device, wherein the single piece separation device comprises a plurality of parallel conveyor belts, wherein the conveying speeds of the plurality of parallel conveyor belts are the same or different, and wherein: include: The package position and speed determination module is used to obtain the position coordinates of the package on the single-piece separation device and the corresponding package conveying speed; a priority processing level sorting module, configured to determine the distance of the parcel from the exit of the single piece separation device in the conveying direction based on the position coordinates of the parcel and the parcel conveying speed, and sort the parcels by priority level based on the principle that the closer the distance, the higher the priority level; The conveyor belt speed calculation module determines the processing order of the packages based on the priority processing level, and determines the target conveying speed of each package based on the separation distance threshold, where the separation distance threshold is a preset minimum distance that should be maintained between two adjacent packages; and determines the conveyor belt operating speed based on the conveying speed corresponding to all packages on each conveyor belt section.

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