Parcel stack removing method and system on stack removing device

Abstract

According to the parcel stack removing method and system on the stack removing device, the positions of parcels are detected on the basis of multiple sets of conveying belts with height differences, the positions of the parcels are corrected in combination with a compensation offset formula, and the positions of the parcels on the belts and corresponding speed information are accurately obtained; key indexes such as area distribution, number and positions (front section / middle section / tail section) of the packages on each section of conveyor belt are calculated; on the basis of key indexes, the speed of each section of belt is dynamically adjusted according to inverted-order calculation logic, and a targeted strategy is formulated by combining the parcel position (whether the parcel reaches the tail section or not), the downstream belt state (the number and area threshold) and the like; through accurate position compensation and correction, the problem of detection deviation caused by belt operation delay is solved; by means of reverse-order calculation and multi-gear speed control, dynamic matching of the speed of the upstream belt and the speed of the downstream belt is achieved, and secondary stacking is reduced; the cooperative operation strategy of the inlet conveyor belt avoids parcel slipping, and the delay starting rule of the fall belt reduces the overlapping risk.

Description

Technical Field

[0001] The present invention relates to the field of logistics sorting, and in particular to a package destacking method and system on a destacking device. Background Art

[0002] With the rapid development of e-commerce and smart logistics industries, the global express parcel volume has shown explosive growth, with an average annual growth rate of more than 20%. The average daily parcel processing volume in major markets such as China has exceeded 100 million pieces. Destacking refers to when the automatic parcel separation system starts to operate, a large number of unsorted parcels enter the destacking device from the inlet section, and the stacked pieces are separated in the destacking device, that is, the stacked parcels are separated into parcels that are normally placed flat on the automatic feeding line. In the logistics sorting system, "destacking" at the front end is a key link that determines the overall efficiency. This link requires separating a large number of stacked and messy objects (such as packaging bags, boxes, etc.) unloaded from the container, so that they can smoothly enter the subsequent sorting equipment at a preset spacing or dynamic spacing, which directly affects the processing speed and accuracy of the sorting system.

[0003] In the existing technology, the destacking and single-piece separation links have long had problems with low automation and limited efficiency; traditional manual operations rely on human sorting, which is not only costly and labor-intensive, but also difficult to adapt to the flow demand during peak hours, and is prone to unstable separation effects due to human errors; early automated equipment mostly used fixed-speed belt conveyors, and only achieved simple separation through mechanical structures (such as baffles and drops), and was unable to dynamically adjust strategies according to the real-time distribution of objects. Problems such as "secondary stacking" and "uneven spacing" often occurred, causing subsequent sorting equipment to become stuck or inefficient. Summary of the Invention

[0004] In response to the shortcomings of the existing technology, the present invention proposes a package destacking method and system on a destacking device to solve the technical problems in the existing technology that the strategy cannot be dynamically adjusted according to the real-time distribution of objects, and problems such as "secondary stacking" and "uneven spacing" often occur, resulting in blockage of subsequent sorting equipment or reduced efficiency.

[0005] To solve the above technical problems, in a first aspect, the present invention provides a method for destacking packages on a destacking device, wherein the destacking device includes a plurality of conveyor belt sections, the plurality of conveyor belt sections being arranged in a stepped manner and arranged in descending order along a conveying direction. The method comprises the following steps:

[0006] S1. Obtaining location information of packages on each section of the conveyor belt of the destacking device;

[0007] S2. Determine key indicator information for each section of the conveyor belt based on the location information; the key indicator information includes parcel area distribution and the number of parcels, the parcel area distribution including total area ratio and regional area ratio; the total area ratio is the area ratio of all parcels on a single section of the conveyor belt, and the regional area ratio is the sub-area ratio of parcels within a preset area on the conveyor belt;

[0008] S3. Starting from the last section of the conveyor belt in the conveying direction of the de-stacking device, determine whether each section of the conveyor belt has a stacking risk in turn according to the key indicator information along the reverse conveying direction; if it is determined that the current section of the conveyor belt has a stacking risk, reduce the conveying speed of the adjacent previous section of the conveyor belt according to the preset rules.

[0009] Preferably, in S3, judging in sequence whether there is a stacking risk in each section of the conveyor belt according to the key indicator information specifically includes:

[0010] If the total area ratio of the current section of the conveyor belt exceeds the preset first ratio threshold; or

[0011] If the number of packages on the current conveyor belt exceeds the preset quantity accumulation threshold; or

[0012] Determining, based on the sub-area proportions, that the parcels are concentrated in a preset front section of the current conveyor belt;

[0013] It is determined that there is a risk of stacking in the current section of the conveyor belt.

[0014] Preferably, the S1 specifically includes:

[0015] S11, acquiring an image of each conveyor belt on the destacking device, performing package position detection on the image based on a trained position detection model, and determining initial position information of each package;

[0016] S12. Obtain the conveying speed of the conveyor belt when the previous frame of image is captured, the time difference between acquiring the image and determining the position information, the average processing time of the position detection model, and the control delay time of the de-stacking device; determine the delay offset based on the time difference, the average processing time and the control delay time; determine the position compensation offset according to the conveying speed of the conveyor belt when the previous frame of image is captured and the delay offset; and determine the position information after the offset compensation according to the position compensation offset and the initial position information.

[0017] Preferably, in S12, the delay offset is:

[0018] D x_offset =V last *(T handle -T frame +TavgDelay +T plcDelay )

[0019] Among them, D x_offset is the delay offset of package x, T handle The time to obtain the initial position information 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 conveying speed of the conveyor belt when the last frame of image is captured;

[0020] The position information after offset compensation is determined as:

[0021] D x_new =D x +D x_offset

[0022] Among them, D x_new To compensate for the offset position information, D x The initial position information of package x determined in the current frame image.

[0023] Preferably, in S3, each section of the conveyor belt is divided into a preset front section area, a preset middle section area and a preset rear section area according to a preset ratio; wherein the preset front section area is close to the previous section of the conveyor belt, and the preset rear section area is close to the next section of the conveyor belt;

[0024] The quantity accumulation threshold includes a first quantity accumulation threshold, a second quantity accumulation threshold, a first proportion threshold and a second proportion threshold; the first quantity accumulation threshold is less than the second quantity accumulation threshold;

[0025] Each section of the conveyor belt includes a plurality of speed gears, and along the conveying direction, the conveying speed of the same speed gear of each conveyor belt increases in sequence.

[0026] Preferably, in S3, if it is determined that there is a risk of stacking in the current section of the conveyor belt, the conveying speed of the adjacent previous section of the conveyor belt is reduced according to a preset rule, specifically including:

[0027] When there are packages that have not yet reached the preset rear section of the conveyor belt, the number of packages currently on the conveyor belt is compared with a first accumulation threshold. If the number of packages is not less than the first accumulation threshold, the conveyor belt is in a high speed gear, which includes the highest speed gear and one or more speed gears sequentially adjacent to the highest speed gear.

[0028] When a package arrives at a preset rear section of the conveyor belt, the number of packages on the current conveyor belt is compared with a first accumulation threshold. If the number of packages is greater than the first accumulation threshold, the current conveyor belt adopts a low speed gear, wherein the low speed gear includes the lowest speed gear and one or more speed gears sequentially adjacent to the lowest speed gear.

[0029] When the next conveyor belt adjacent to the current conveyor belt switches from a stopped state to a moving state, if the state of the current belt also needs to switch from a stopped state to a moving state, and there is a package in the preset front area of ​​the next conveyor belt, the current conveyor belt will be delayed for the preset delay start time;

[0030] When a package arrives at the preset rear section of the conveyor, if the number of packages on the next or next two conveyor belts exceeds the second quantity accumulation threshold, or the total area ratio exceeds the preset first ratio threshold, the current conveyor belt stops conveying.

[0031] Preferably, the S3 further includes:

[0032] If there is a package in the preset rear section of the adjacent conveyor belt, the adjacent next section will run at least at the lowest speed gear;

[0033] If it is known that there is a risk of stacking of equipment adjacent to the last conveyor section of the de-stacking device, the last conveyor section is stopped;

[0034] If it is known based on the parcel area distribution that there are parcels on one or more conveyor belts upstream of the de-duplication device, and there are no parcels on all conveyor belts downstream of the de-duplication device, it is determined that there is abnormal slippage or jamming, and the induction section is controlled to deliver the parcels, and the slipping or jammed parcels are pushed by delivering the parcels; if it is known based on the parcel area distribution that one or more conveyor belts upstream of the de-duplication device cannot reach the set parcel area distribution threshold within the set time, it is determined that the flow of the de-duplication device is insufficient, and the induction section is controlled to deliver the parcels.

[0035] If it is determined based on the parcel area distribution that there are no parcels in the preset front section of the first conveyor belt on the de-stacking device, or the number of parcels does not reach the first quantity accumulation threshold, or the sub-area ratio does not reach the set parcel area ratio threshold, the induction section is controlled to start delivering the parcels.

[0036] In a second aspect, the present invention provides a package destacking system for a destacking device, the destacking device comprising a plurality of conveyor belt sections, the plurality of conveyor belt sections being arranged in a stepped manner and arranged in descending order along a conveying direction. The package destacking system comprises:

[0037] a package position and speed determination module for obtaining the position information of the package on each section of the conveyor belt of the de-stacking device and the speed information of the conveyor belt;

[0038] a key indicator determination module for determining key indicator information on each section of the conveyor belt based on the location information; the key indicator information includes parcel area distribution and the number of parcels, the parcel area distribution including total area ratio and regional area ratio; the total area ratio is the area ratio of all parcels on a single section of the conveyor belt, and the regional area ratio is the sub-area ratio of parcels within a preset area on the conveyor belt;

[0039] The conveyor belt running speed calculation module starts with the last section of the conveyor belt in the conveying direction of the de-stacking device, and judges whether there is a stacking risk for each section of the conveyor belt in turn according to the key indicator information along the reverse conveying direction; if it is judged that there is a stacking risk for the current section of the conveyor belt, the conveying speed of the adjacent previous section of the conveyor belt is reduced according to the preset rules.

[0040] In summary, the present invention provides a package de-stacking method and system on a de-stacking device. The system uses multiple sets of conveyor belts with height differences as the hardware basis to detect the package position, and corrects the package position in combination with a compensation offset formula (taking into account delay parameters such as the coordinate receiving time and the image acquisition time), accurately obtaining the package position and corresponding speed information on the belt; calculating key indicators such as the area distribution, quantity, and location (front section / middle section / end section) of the packages on each conveyor belt section; based on the key indicators, dynamically adjusting the speed of each belt section according to the reverse calculation logic, taking into account the package position (whether it has reached the end section), the downstream belt status (quantity, area threshold), etc. Formulate targeted strategies; solve the detection deviation problem caused by belt operation delay through precise position compensation correction; reverse calculation and multi-gear speed control realize dynamic matching of upstream and downstream belt speeds, reducing secondary stacking; the coordinated operation strategy of the entrance conveyor belt avoids package slippage, and the delayed start rule of the drop belt reduces the risk of overlap; the multi-threshold judgment mechanism (quantity, area) improves the ability to handle abnormal situations such as overlapped parts and insufficient flow, effectively improving the separation accuracy and operation stability of the de-stacking device, providing reliable input for the subsequent single-piece separation link, and adapting to the needs of high-flow logistics scenarios. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] 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.

[0042] Figure 1 is a flow chart of a package destacking method on a destacking device according to an embodiment of the present invention;

[0043] Figure 2Schematic diagram of the structure of the automatic parcel separation system according to an embodiment of the present invention;

[0044] Figure 3 FIG. 4 is a structural schematic diagram of a package destacking system on a destacking device according to an embodiment of the present invention. DETAILED DESCRIPTION

[0045] 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.

[0046] See also Figure 1-Figure 3 An embodiment of the present invention provides a method for destacking packages on a destacking device. The method comprises: the destacking device comprising a plurality of conveyor belt sections, the plurality of conveyor belt sections being arranged in a stepped manner, adjacent conveyor belt sections having a height difference, and the plurality of conveyor belt sections being arranged in descending order along a conveying direction. The method comprises the following steps:

[0047] S1. Obtaining location information of packages on each section of the conveyor belt of the destacking device;

[0048] Among them, Figure 2 As shown in the figure, the core function of the de-stacking device is to separate the stacked and disordered packages entering from the induction section into single, smoothly arranged packages through the coordinated operation of the conveyor belt (speed adjustment, drop coordination, etc.), providing qualified input for the subsequent single-piece separation equipment. Specifically, it includes:

[0049] Receiving and conveying packages: Through the continuous operation of multiple-section belts, the packages in the inlet section are gradually conveyed to the downstream;

[0050] Eliminate stacking: Utilize speed and height differences between belts, combined with visual inspection and dynamic speed control, to separate stacked packages into single layers.

[0051] Adapt to downstream needs: By calculating the belt speed in reverse order and adjusting the output rhythm according to the status of the single-piece separation equipment, downstream congestion or insufficient flow can be avoided.

[0052] Said S1 specifically includes:

[0053] S11, acquiring an image of each conveyor belt on the destacking device, performing package position detection on the image based on a trained position detection model, and determining initial position information of each package;

[0054] Specifically, by deploying target cameras at key positions of the de-stacking device, images of each section of the conveyor belt are collected in real time to ensure that the operating areas of all conveyor belts are 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, and output the initial coordinates of each package in the image coordinate system (such as the x-axis and y-axis coordinates), 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 shooting, and does not take into account factors such as belt operation delay, and requires subsequent compensation and correction.

[0055] S12. Obtain the conveying speed of the conveyor belt when the previous frame of image is captured, the time difference between acquiring the image and determining the position information, the average processing time of the position detection model, and the control delay time of the de-stacking device; determine the delay offset based on the time difference, the average processing time and the control delay time; determine the position compensation offset according to the conveying speed of the conveyor belt when the previous frame of image is captured and the delay offset; and determine the position information after the offset compensation according to the position compensation offset and the initial position information.

[0056] Because the conveyor belt is constantly running, the package moves along the belt during the process from image acquisition to position information being used for control. This can cause a deviation between the "initial position information" and the actual position. This step corrects this deviation by calculating the offset.

[0057] The time difference between the image and the determined position information is the difference between the time when the camera captures the current frame image and the time when the control unit of the de-stacking device receives the initial position information output by the position detection model.

[0058] The average processing time of the location detection model refers to the average time it takes for the location detection model (such as YOLOv5) to process a single frame of image and output package location information. It is calculated by the system based on recent processing time statistics and reflects the model's computational latency.

[0059] The control delay time of the de-stack device refers to the delay time from the control unit (such as a PLC) receiving the position information and issuing the control command to the actuator (such as a motor) responding, including the time consumed by signal transmission and mechanical response.

[0060] Among them, the conveying speed of the conveyor belt when the previous frame of image is captured refers to the current running speed of the conveyor belt (unit: mm / s) when the camera captures the previous frame of image, which is fed back in real time by the belt speed sensor and is used to calculate the moving distance of the belt during the delay time.

[0061] In S12, the delay offset is:

[0062] D x_offset =V last *(Thandle -T frame +T avgDelay +T plcDelay )

[0063] Among them, D x_offset is the delay offset of package x, T handle The time to obtain the initial position information 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 conveying speed of the conveyor belt when the last frame of image is captured;

[0064] The position information after offset compensation is determined as:

[0065] D x_new =D x +D x_offset

[0066] Among them, D x_new To compensate for the offset position information, D x The initial position information of package x determined in the current frame image.

[0067] S2. Determine key indicator information for each section of the conveyor belt based on the location information; the key indicator information includes parcel area distribution and the number of parcels, the parcel area distribution including total area ratio and regional area ratio; the total area ratio is the area ratio of all parcels on a single section of the conveyor belt, and the regional area ratio is the sub-area ratio of parcels within a preset area on the conveyor belt;

[0068] Specifically, first determine the physical dimensions of a single conveyor belt section (such as length and width) and calculate its total area (belt length × width);

[0069] Divide the single-section belt into three preset areas according to the preset ratio (usually 1:2:1, which can be adjusted according to the effect):

[0070] Preset front section area: the area close to the upstream (introduction section) of the assembly line;

[0071] Preset middle area: the area between the front and end sections (largest proportion);

[0072] Preset rear section area: the area close to the downstream of the assembly line (the next section of the belt).

[0073] Based on the compensated parcel location information from S1, the system determines whether each parcel's coordinates fall within the physical range of the current belt section (using a coordinate threshold). The system then counts the total number of parcels within this range, representing the "number of parcels on a single conveyor belt section." This includes area distribution, which quantifies the space occupied by parcels on the belt, including "total area share" and "regional area share," reflecting both the overall and local distribution density of parcels.

[0074] Parcel Area Distribution is quantified by Total Area Share and Regional Area Share, and is calculated as follows:

[0075] According to the package bounding box output by the location detection model (such as the package outline selected by the YOLOv5 algorithm), combined with the ratio between the image and the actual physical size (such as pixels / mm), the pixel area of ​​the bounding box is converted into the actual physical area (such as mm). 2 ).

[0076] Calculate the “total area share”:

[0077] Sum up the actual physical area of ​​all packages on a single section of conveyor belt to get the "total package area of ​​a single section of belt";

[0078] Total area ratio = (total wrapped area of ​​a single belt section ÷ total area of ​​a single belt section) × 100%, reflecting the overall load level of a single belt section.

[0079] Calculate the “regional area share”:

[0080] Count the actual physical area of ​​all packages in each preset area (front, middle, and end) to obtain the "total package area of ​​the area";

[0081] Regional area ratio = (total parcel area of ​​the region ÷ area of ​​the region) × 100% (or ÷ total area of ​​a single belt section, focusing on reflecting regional distribution, usually based on the area of ​​the region itself), reflecting the local concentration of parcels on a single belt section (for example, a high ratio of the front section area indicates that the parcels are concentrated on the entrance side).

[0082] Through the above steps, the system can convert the location information of the package into quantitative key indicators, providing a clear and executable basis for the subsequent "reverse calculation of belt speed based on key indicators".

[0083] S3. Starting from the last section of the conveyor belt in the conveying direction of the de-stacking device, determine whether each section of the conveyor belt has a stacking risk in turn according to the key indicator information along the reverse conveying direction; if it is determined that the current section of the conveyor belt has a stacking risk, reduce the conveying speed of the adjacent previous section of the conveyor belt according to the preset rules.

[0084] The key indicator information is used to determine whether each section of the conveyor belt has a stacking risk, specifically including:

[0085] If the total area ratio of the current section of the conveyor belt exceeds the preset first ratio threshold; or

[0086] If the number of packages on the current conveyor belt exceeds the preset quantity accumulation threshold; or

[0087] Determining, based on the sub-area proportions, that the parcels are concentrated in a preset front section of the current conveyor belt;

[0088] It is determined that there is a risk of stacking in the current section of the conveyor belt.

[0089] To facilitate understanding of the implementation logic of step S3, this embodiment specifically illustrates the stacking risk assessment and speed adjustment process based on a typical structure of a de-stacking device (e.g., a total of six belt sections, each group including upper and lower belt sections with a drop, numbered sequentially as belt 1 to belt 6, with belt 6 being the downstreammost exit belt that interfaces with a single-piece separation device):

[0090] The 6 belt sections are arranged in the following order according to the transmission direction: belt 1 (entry belt, upstream) → belt 2 → belt 3 → belt 4 → belt 5 → belt 6 (exit belt, downstream); each belt section is divided into a preset front section (25%, close to the upstream), middle section (50%), and end section (25%, close to the downstream) in a ratio of 1:2:1.

[0091] Key threshold presets (adjustable based on debugging experience):

[0092] First percentage threshold: 60% (if the total area of ​​a single belt section exceeds this value, it is judged to be overloaded);

[0093] Quantity accumulation threshold: 5 (if the number of packages on a single belt exceeds this value, it will be considered as excessive);

[0094] Regional concentration judgment standard: the sub-area ratio of the preset front section area is ≥50% (that is, the area of ​​the front section package accounts for more than 50% of the area of ​​the front section area, and it is judged that the package is concentrated in the front section).

[0095] Taking "starting from the last belt section (belt 6) and moving in the reverse direction to belt 1" as an example, the specific steps are as follows:

[0096] Step 1: Determine the stacking risk of belt 6 (export belt, docking single-disconnect equipment)

[0097] Get key metrics:

[0098] Total area ratio: total area of ​​all packages on belt 6 ÷ area of ​​belt 6 = 55%;

[0099] Number of packages: 4;

[0100] Area ratio (front section): belt 6 front section wrapping area ÷ front section area = 30%.

[0101] Risk Assessment:

[0102] The total area ratio (55%) is less than the first ratio threshold (60%), the number (4) is less than the number accumulation threshold (5), and the area ratio of the front segment (20%) is less than 30%, so it is determined that there is no stacking risk.

[0103] Impact on upstream belt 5: Belt 6 has no risk, and belt 5 does not need to reduce its speed due to the risk of belt 6 (it will be adjusted according to its own indicators later).

[0104] Step 2: Determine the stacking risk of belt 5 (the lower belt with a drop, and belt 4 upstream)

[0105] Get key metrics:

[0106] Total area share: 70% (>60%);

[0107] Number of packages: 6 (>5);

[0108] Regional area share (front section): 50% (>30%, packages are concentrated in the front section).

[0109] Risk assessment: If the three conditions of "total area percentage exceeds the threshold", "number exceeds the threshold" and "concentration in the front section" are met, it is determined that there is a high stacking risk.

[0110] When there is a high risk of stacking, belt No. 4 will stop after delivering the packages on it to the rear section instead of slowing down. It will not start until the high risk of stacking on belt No. 5 is eliminated due to the movement of the packages. The starting speed is determined by the package quantity threshold 1 and whether the packages have reached the rear section.

[0111] For example, if the package on belt No. 4 has not reached the rear section, and the package quantity threshold 1 is set to 3, then if there are 4 packages, the third speed (1200) is used, and if there are 2 packages, the fourth speed (1500) is used; if the package on belt No. 4 has reached the rear section, it is necessary to check whether there is a high-risk overlap on belt No. 5. If so, stop belt No. 4 directly. If there is no high risk, still check the package quantity threshold 1 and run at the first speed (500) and the second speed (700) respectively.

[0112] Step 3: Determine the stacking risk of belt 4 (the upper belt of the drop, and belt 5 downstream)

[0113] Get key metrics:

[0114] Total area share: 40% (<60%);

[0115] Number of packages: 3 (<5);

[0116] Regional area share (front part): 20% (<50%).

[0117] Risk assessment: No stacking risk.

[0118] Impact on upstream belt 3: Belt 4 has no risk, and belt 3 does not need to reduce its speed due to the risk of belt 4. However, it needs to be indirectly adjusted based on the risk of belt 5 (because belt 5 has a risk, belt 4 has reduced its speed, and belt 3 can maintain its current speed or make fine adjustments).

[0119] Step 4: Determine the stacking risk of belt 3 (and so on)

[0120] If the total area of ​​belt 3 accounts for 50%, the number is 4, and the front section accounts for 30%, there is no risk and belt 2 does not need to be reduced in speed;

[0121] If the total area of ​​belt 3 accounts for 65% (exceeding the threshold), it is determined that there is a risk, and belt 2 needs to be reduced from the current fourth speed (1500 units) to the third speed (1200 units).

[0122] Step 5: Determine the stacking risk of belt 2 and belt 1

[0123] According to the above logic, if there is a risk in belt 2, the speed of belt 1 will be reduced; if there is a risk in belt 1 (such as the total area accounts for 70% and the number is 6), the speed of the upstream inlet section needs to be controlled to reduce the amount of parts delivered to belt 1.

[0124] Based on the above embodiment, as a preferred implementation, in S3, each section of the conveyor belt is divided into a preset front section area, a preset middle section area, and a preset rear section area according to a preset ratio; wherein the preset front section area is close to the previous section of the conveyor belt, and the preset rear section area is close to the next section of the conveyor belt;

[0125] The quantity accumulation threshold includes a first quantity accumulation threshold, a second quantity accumulation threshold, a first proportion threshold and a second proportion threshold. The first proportion threshold represents the upper limit of the area proportion of the total packages on the conveyor belt. If it is greater than the first proportion threshold, it means that there are too many packages on the corresponding conveyor belt and there is a risk of stacking. The second proportion threshold represents the upper limit of the area proportion of the packages in the area to the preset (front section, middle section, and rear section) area. If it is greater than the second proportion threshold, it means that there are too many packages in the preset (front section, middle section, and rear section) area. The first quantity accumulation threshold is less than the second quantity accumulation threshold.

[0126] Each section of the conveyor belt includes multiple speed gears, and along the conveying direction, the conveying speed of the same speed gear of the next conveyor belt is not lower than the conveying speed of the same speed gear of the adjacent previous conveyor belt. In the entire de-duplication device, the speeds of the corresponding gears of the belts at different positions (from the upstream belt near the introduction section to the downstream belt near the separation device) show an increasing trend. For example, assuming that the de-duplication device has 6 belt sections (from upstream to downstream, belt A, belt B, belt C, belt D, belt E, belt F), then:

[0127] The first speed of belt A (upstream) may be 250, the second speed 550, the third speed 1000, and the fourth speed 1300; the first quantity threshold is 4, the second quantity threshold is 8, the first area threshold is 0.8, and the second area threshold is 0.5;

[0128] The first speed of belt B (upstream) is 250, the second speed is 600, the third speed is 1000, and the fourth speed is 1200; the first quantity threshold is 4, the second quantity threshold is 7, the first area threshold is 0.7, and the second area threshold is 0.4;

[0129] The first speed of belt C (midstream) is 350, the second speed is 600, the third speed is 1200, and the fourth speed is 1350; the first quantity threshold is 4, the second quantity threshold is 7, the first area threshold is 0.6, and the second area threshold is 0.3;

[0130] The first speed of belt D (midstream) is 350, the second speed is 650, the third speed is 1200, and the fourth speed is 1350; the first quantity threshold is 4, the second quantity threshold is 6, the first area threshold is 0.5, and the second area threshold is 0.2;

[0131] The first speed of belt E (downstream) is 450, the second speed is 650, the third speed is 1500, and the fourth speed is 1500; the first quantity threshold is 3, the second quantity threshold is 6, the first area threshold is 0.5, and the second area threshold is 0.2;

[0132] The first speed of belt F (downstream) is 450, the second speed is 700, the third speed is 1500, and the fourth speed is 1500; the first quantity threshold is 3, the second quantity threshold is 5, the first area threshold is 0.4, and the second area threshold is 0.1.

[0133] It can be seen that no matter the first speed, the second speed, or the third and fourth speeds, they all show the rule of "upstream belt gear speed < midstream belt gear speed < downstream belt gear speed".

[0134] Based on the above embodiment, as a preferred implementation, in S3, if it is determined that there is a risk of stacking in the current section of the conveyor belt, the conveying speed of the adjacent previous section of the conveyor belt is reduced according to a preset rule, specifically including:

[0135] If packages have not yet reached the preset rear section of the conveyor belt, the number of packages on the current conveyor belt is compared with a first accumulation threshold. If the number of packages is not less than the first accumulation threshold, the current conveyor belt uses a high speed gear, which includes the highest speed gear and one or more speed gears adjacent to the highest speed gear. The "preset rear section" refers to the last section of the single belt divided in a 1:2:1 ratio (accounting for 25%, close to the downstream). "Has not yet reached the rear section" means that the packages are concentrated in the front section (25%) or middle section (50%). At this time, the belt needs to run at high speed to quickly transport the packages to the last section to avoid accumulation in the front / middle section.

[0136] Assume that belt 4 is an upper drop belt, and its preset rear section is the end section (25% of the length). If all packages on belt 4 are in the middle section (not at the end section):

[0137] When the number of packages is 4 (≥ threshold 3), the third speed of 1200 is used to transport the packages to the end section at a higher speed while avoiding collisions with other packages due to excessive speed.

[0138] When the number of packages is 2 (<threshold 3), the fourth speed 1500 (highest gear) is used to quickly clear the front / middle space at high speed to make room for new packages and reduce the risk of accumulation.

[0139] When a package arrives at the preset rear section of the conveyor belt, the number of packages on the current conveyor belt is compared with a first accumulation threshold. If the number of packages exceeds the first accumulation threshold, the current conveyor belt adopts a low speed gear, which includes the lowest speed gear and one or more speed gears adjacent to the lowest speed gear. The "preset rear section" is the last section, at which time the package is about to enter the next section of the belt. The speed needs to adapt to the downstream state to avoid stacking in the next section due to excessively fast delivery.

[0140] When the number of packages at the last section is too large (exceeding the first threshold), it needs to be transported at a low speed to reduce the frequency of delivery to the next section; if the number is moderate, a slightly higher speed is used to ensure stable flow.

[0141] Example scenario:

[0142] Assume that belt 5 is the lower section of the belt with a drop, and there are packages at the end of the belt (about to enter belt 6). The first accumulation threshold is set to 5:

[0143] When the number of packages on belt 5 reaches 6 (> threshold 5), the first speed of 600 (lowest gear) is used to slowly deliver the last package to belt 6 to prevent belt 6 from stacking due to receiving packages too quickly;

[0144] When the number of packages is 4 (≤ threshold 5), the second speed of 800 is used to deliver the packages at a moderate speed, ensuring that there are enough packages downstream without causing congestion.

[0145] When the next section of the conveyor belt adjacent to the current conveyor belt changes from a stopped state to a moving state, if the state of the current belt also needs to change from a stopped state to a moving state, and there is a package in the preset front area of ​​the next section of the conveyor belt, the current conveyor belt will be delayed according to the preset delayed start time; the delay is used to avoid overlapping of packages at the drop. Due to the height difference between the upper and lower sections of the drop, if there is a package in front of the lower section, the package in the upper section will fall directly and stack on top of it.

[0146] Preset front section area: the front section of the next belt section (lower section of drop) (25% length, close to the drop point of the upper belt section).

[0147] Default delay start time: As described in the document, it is set to 100ms (adjustable and modifiable), which is enough for the front package of the lower section to move to the middle section, making room for the packages of the upper section.

[0148] Example scenario:

[0149] Belt 3 is the upper section of the drop belt, and the adjacent next section of belt 4 is the lower section of the drop belt (there is a height difference). Previously, both of them stopped running due to downstream congestion. Now that the downstream has recovered, both need to be put into motion:

[0150] The system detects a package in the preset front section of belt 4 (not moved to the middle section);

[0151] Belt 3 needs to be started with a delay of 100ms. After belt 4 has transported the packages in the front section to the middle section, belt 3 can be started again. When the packages on belt 3 fall, there will be no packages in the front section of belt 4 to avoid overlap.

[0152] When a package reaches the pre-set rear section of a conveyor, if the number of packages on the next or next two conveyor sections exceeds the second accumulation threshold, or if the total area exceeds the pre-set first percentage threshold, the current conveyor stops. By monitoring the load on the downstream belt, the current belt is controlled to stop delivering packages to avoid further accumulation downstream. The monitoring range varies depending on the type of belt.

[0153] Second accumulation threshold: a higher threshold than the first threshold (e.g., set to 8), used to determine whether the downstream is "saturated";

[0154] The first percentage threshold: as stated in the document, it is set to 60% (if the proportion of the total area of ​​the downstream belt exceeds this value, it is judged to be overloaded);

[0155] Monitoring scope:

[0156] Except for the overlapping entrance belt and the lower section belt of the drop: monitor the next adjacent section of the belt;

[0157] Upper belt section with drop: monitor the next section and the next two sections of belt (the document states that it is necessary to monitor one more section because the drop is prone to misjudgment);

[0158] Example scenario:

[0159] Belt 2 is the belt for removing the stacking entrance, with a wrap at the end. The next section is belt 3:

[0160] If the number of packages on belt 3 reaches 9 (> the second threshold of 8), or the total area accounts for 65% (> the first threshold of 60%), belt 2 stops conveying and avoids sending further packages to belt 3;

[0161] Belt 3 is the upper section of the belt with a drop, and the end section is wrapped. The next section is belt 4, and the next section is belt 5:

[0162] If the number of belts 4 is 7 (≤8) but the total area of ​​belt 5 accounts for 70% (>60%), belt 3 still needs to be stopped because the next two sections are monitored to ensure that there is no congestion downstream of the drop.

[0163] Based on the above embodiment, as a preferred implementation, S3 further includes:

[0164] If there are packages in the preset rear section of the adjacent conveyor belt, the next section will run at least at the lowest speed. The coordinated operation of the two adjacent belt sections can avoid "packages waiting to be transported at the end of the previous section, while the speed of the next section is too low, resulting in package accumulation." Take the upper drop belt (belt 3) and the lower drop belt (belt 4) as an example (there is a height difference between the two):

[0165] If there are two packages at the end of belt 3 (preset rear section) (about to fall into belt 4 through the drop), belt 4 must run at least at the first speed (600), and cannot stop or fall below 600 even if the number of packages on belt 4 is small (such as 1);

[0166] If belt 4 needs to slow down due to congestion downstream, it must maintain the first speed at least to ensure that the packages at the end of belt 3 can be transported to the middle section of belt 4 in time after falling, to avoid accumulation at the drop point (especially round packages are easily stuck due to the stationary state of the next section).

[0167] If it is known that there is a risk of stacking in the equipment adjacent to the last section of the conveyor belt of the de-stacking device, the last section of the conveyor belt will stop; the exit belt will stop to avoid further delivery of parts to the congested separation equipment.

[0168] If it is known based on the parcel area distribution that there are parcels on one or more conveyor belts upstream of the de-duplication device, and there are no parcels on all conveyor belts downstream of the de-duplication device, it is determined that there is abnormal slippage or jamming, and the induction section is controlled to deliver the parcels, and the slipping or jammed parcels are pushed by delivering the parcels; if it is known based on the parcel area distribution that one or more conveyor belts upstream of the de-duplication device cannot reach the set parcel area distribution threshold within the set time, it is determined that the flow of the de-duplication device is insufficient, and the induction section is controlled to deliver the parcels.

[0169] Scenario 1: Abnormal slippage or jamming

[0170] If visual inspection shows that the three upstream belt sections (such as belts 1-3) have a parcel (area distribution ≠ 0), but the area distribution of the downstream belts (4-6) is 0 (no parcel), it means that the parcel is slipping (not moving with the belts) or is stuck (stuck by the mechanical structure) between the upstream and downstream belts;

[0171] At this time, the inlet section (the upstream feeding section connected to the de-stacking device) is controlled to start feeding, and the slipped / stuck packages are driven to continue to move downstream by the thrust of the new packages (for example, the inlet section feeds at the third speed of 1200, pushing the stuck packages on belt 1 onto belt 2).

[0172] Scenario 2: Determined to have insufficient flow in the de-stacking device

[0173] Set a preset "set time" (e.g., 30 seconds) and a preset threshold (e.g., the total number of packages on the three upstream belt sections is ≥ 5). If the number of packages on the three upstream belt sections does not reach 5 within 30 seconds (the total number is insufficient), it indicates that the induction section is under-supplied, causing the subsequent links of the de-duplication device (e.g., the separation device) to run idle due to lack of packages.

[0174] At this time, the inlet section is controlled to start feeding (e.g., feeding at the fourth speed of 1500) to replenish the number of upstream packages, ensure that the de-stacking device has enough packages to separate, and maintain the operating efficiency of the downstream separation equipment.

[0175] If it is determined based on the parcel area distribution that there are no parcels in the preset front section of the first conveyor belt on the de-stacking device, or the number of parcels does not reach the first quantity accumulation threshold, or the sub-area ratio does not reach the set parcel area ratio threshold, the induction section is controlled to start delivering the parcels.

[0176] In a second aspect, the present invention provides a package destacking system on a destacking device, wherein the destacking device includes a plurality of conveyor belt sections, wherein the plurality of conveyor belt sections are arranged in a stepped manner and arranged in descending order along the conveying direction. Based on the package destacking method on the destacking device in the above embodiment, as Figure 3 As shown in , the package destacking system includes:

[0177] The package position and speed determination module 310 obtains the position information of the package on each section of the conveyor belt of the de-stacking device and the speed information of the conveyor belt;

[0178] A key indicator determination module 320 determines key indicator information for each section of the conveyor belt based on the location information; the key indicator information includes parcel area distribution and the number of parcels, the parcel area distribution includes a total area ratio and a regional area ratio; the total area ratio is the area ratio of all parcels on a single section of the conveyor belt, and the regional area ratio is the sub-area ratio of parcels within a preset area on the conveyor belt;

[0179] The conveyor belt running speed calculation module 330 starts with the last section of the conveyor belt in the conveying direction of the de-stacking device, and judges whether there is a stacking risk for each section of the conveyor belt in turn according to the key indicator information along the reverse conveying direction; if it is determined that there is a stacking risk for the current section of the conveyor belt, the conveying speed of the adjacent previous section of the conveyor belt is reduced according to the preset rules.

[0180] 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 package destacking method on a destacking device, characterized in that: The destacking device includes a plurality of conveyor belt sections, the plurality of conveyor belt sections are arranged in a stepped manner, and the plurality of conveyor belt sections are arranged in sequence from high to low along the conveying direction. The package destacking method includes the following steps: S1. Obtaining location information of packages on each section of the conveyor belt of the destacking device; S2. Determine key indicator information for each section of the conveyor belt based on the location information; the key indicator information includes parcel area distribution and the number of parcels, the parcel area distribution including total area ratio and regional area ratio; the total area ratio is the area ratio of all parcels on a single section of the conveyor belt, and the regional area ratio is the sub-area ratio of parcels within a preset area on the conveyor belt; S3. Starting from the last section of the conveyor belt in the conveying direction of the de-stacking device, determine whether each section of the conveyor belt has a stacking risk in turn according to the key indicator information along the reverse conveying direction; if it is determined that the current section of the conveyor belt has a stacking risk, reduce the conveying speed of the adjacent previous section of the conveyor belt according to the preset rules.

2. The package destacking method on the destacking device according to claim 1, characterized in that: In S3, whether there is a stacking risk in each section of the conveyor belt is determined in sequence based on the key indicator information, specifically including: If the total area ratio of the current section of the conveyor belt exceeds the preset first ratio threshold; or If the number of packages on the current conveyor belt exceeds the preset quantity accumulation threshold; or Determining, based on the sub-area proportions, that the parcels are concentrated in a preset front section of the current conveyor belt; It is determined that there is a risk of stacking in the current section of the conveyor belt.

3. The package destacking method on the destacking device according to claim 1, characterized in that: Said S1 specifically includes: S11, acquiring an image of each conveyor belt on the destacking device, performing package position detection on the image based on a trained position detection model, and determining initial position information of each package; S12. Obtain the conveying speed of the conveyor belt when the previous frame of image is captured, the time difference between acquiring the image and determining the position information, the average processing time of the position detection model, and the control delay time of the de-stacking device; determine the delay offset based on the time difference, the average processing time and the control delay time; determine the position compensation offset according to the conveying speed of the conveyor belt when the previous frame of image is captured and the delay offset; and determine the position information after the offset compensation according to the position compensation offset and the initial position information.

4. The package destacking method on the destacking device according to claim 3, 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 information 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 conveying speed of the conveyor belt when the last frame of image is captured; The position information after offset compensation is determined as: D x_new =D x +D x_offset Among them, D x_new To compensate for the offset position information, D x The initial position information of package x determined in the current frame image.

5. The package destacking method on the destacking device according to claim 2, characterized in that: In S3, each section of the conveyor belt is divided into a preset front section area, a preset middle section area, and a preset rear section area according to a preset ratio; wherein the preset front section area is close to the previous section of the conveyor belt, and the preset rear section area is close to the next section of the conveyor belt; The quantity accumulation threshold includes a first quantity accumulation threshold, a second quantity accumulation threshold, a first proportion threshold and a second proportion threshold; the first quantity accumulation threshold is less than the second quantity accumulation threshold; Each section of the conveyor belt includes a plurality of speed gears, and along the conveying direction, the conveying speed of the same speed gear of each conveyor belt increases in sequence.

6. The package destacking method on the destacking device according to claim 5, characterized in that: In S3, if it is determined that there is a risk of stacking in the current section of the conveyor belt, the conveying speed of the adjacent previous section of the conveyor belt is reduced according to a preset rule, specifically including: When there are packages that have not yet reached the preset rear section of the conveyor belt, the number of packages currently on the conveyor belt is compared with a first accumulation threshold. If the number of packages is not less than the first accumulation threshold, the conveyor belt is in a high speed gear, which includes the highest speed gear and one or more speed gears sequentially adjacent to the highest speed gear. When a package arrives at a preset rear section of the conveyor belt, the number of packages on the current conveyor belt is compared with a first accumulation threshold. If the number of packages is greater than the first accumulation threshold, the current conveyor belt adopts a low speed gear, wherein the low speed gear includes the lowest speed gear and one or more speed gears sequentially adjacent to the lowest speed gear. When the next conveyor belt adjacent to the current conveyor belt switches from a stopped state to a moving state, if the state of the current belt also needs to switch from a stopped state to a moving state, and there is a package in the preset front area of ​​the next conveyor belt, the current conveyor belt will be delayed for the preset delay start time; When a package arrives at the preset rear section of the conveyor, if the number of packages on the next or next two conveyor belts exceeds the second quantity accumulation threshold, or the total area ratio exceeds the preset first ratio threshold, the current conveyor belt stops conveying.

7. The package destacking method on the destacking device according to claim 6, characterized in that: Said S3 further comprises: If there is a package in the preset rear section of the adjacent conveyor belt, the adjacent next section will run at least at the lowest speed gear; If it is known that there is a risk of stacking of equipment adjacent to the last conveyor section of the de-stacking device, the last conveyor section is stopped; If it is known based on the parcel area distribution that there are parcels on one or more conveyor belts upstream of the de-duplication device, and there are no parcels on all conveyor belts downstream of the de-duplication device, it is determined that there is abnormal slippage or jamming, and the induction section is controlled to deliver the parcels, and the slipping or jammed parcels are pushed by delivering the parcels; if it is known based on the parcel area distribution that one or more conveyor belts upstream of the de-duplication device cannot reach the set parcel area distribution threshold within the set time, it is determined that the flow of the de-duplication device is insufficient, and the induction section is controlled to deliver the parcels. If it is determined based on the parcel area distribution that there are no parcels in the preset front section of the first conveyor belt on the de-stacking device, or the number of parcels does not reach the first quantity accumulation threshold, or the sub-area ratio does not reach the set parcel area ratio threshold, the induction section is controlled to start delivering the parcels.

8. A package destacking system on a destacking device, characterized in that: The destacking device includes a plurality of conveyor belt sections, the plurality of conveyor belt sections are arranged in a stepped manner, and the plurality of conveyor belt sections are arranged in sequence from high to low along the conveying direction. The package destacking system includes: a package position and speed determination module for obtaining the position information of the package on each section of the conveyor belt of the de-stacking device and the speed information of the conveyor belt; A key indicator determination module determines the key indicator information on each section of the conveyor belt based on the position information; the key indicator information includes the area distribution of packages and the number of packages, and the area distribution of packages includes the total area ratio and the regional area ratio; the total area ratio is the area ratio of all packages on a single section of the conveyor belt, and the regional area ratio is the sub-area ratio of packages in a preset area on the conveyor belt; a conveyor belt running speed calculation module starts with the last section of the conveyor belt in the conveying direction of the de-stacking device, and judges in turn whether there is a stacking risk for each section of the conveyor belt based on the key indicator information along the reverse conveying direction; if it is determined that there is a stacking risk in the current section of the conveyor belt, the conveying speed of the adjacent previous section of the conveyor belt is reduced according to the preset rules.

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