Automatic packing method for narrow-band sorting machine

Abstract

The present invention discloses an automatic packing method for a narrow-band sorting machine; the method is as follows: 1. The parcel passes through a light curtain sensor at a uniform speed. 2. According to the detection result of the light curtain sensor, the coordinates and length of the center point of the occupied area of ​​the parcel are constructed; the occupied area of ​​the parcel is the circumscribed rectangle of the parcel; 3. The remaining packing conveying distance of the parcel, the distance between the actual packing point of the parcel and the starting point of the packing, is calculated; 4. The target car queue is matched for the parcel. 5. The parcel is speed-matched with the target car queue. The present invention uses the detection result of the light curtain sensor to solve the length, width and center point coordinates of the circumscribed rectangle of the parcel whose length side is parallel to the traveling direction of the car; the center point coordinates can determine the actual packing point of the parcel; the length of the circumscribed rectangle can help determine the number of cars in the target car queue; thereby, the best target car queue can be comprehensively obtained, and the speed matching of the parcel with the target car queue can be more accurately performed.

Description

Technical Field

[0001] The invention belongs to the technical field of logistics sorting, and in particular relates to an automatic packing method for a narrow-band sorting machine. Background Art

[0002] In the field of express delivery sorting, the requirements for sorting quality and accuracy are increasing day by day. The existing method of measuring package size is relatively simple, which basically uses a light curtain sensor or a photoelectric sensor group to determine the position of the object on the packaging table, and divides the maximum and minimum difference by two as the center point. This method is still applicable to standard objects, but when facing irregular objects, the calculation results are often inaccurate, which leads to a high rate of wrong packages.

[0003] At present, most sorting machines mainly load parcels by manual feeding. However, due to the high speed of narrow-band sorting machines, the small pitch of sorting carts, and the possibility of multiple carts for one package, multiple loading personnel are often required. This method requires high quality of loading personnel, and the on-site labor intensity of loading personnel is relatively high.

[0004] Compared with automatic packing, the sorting efficiency and capacity of manual packing are significantly lower. However, there are some difficulties in automatic packing. For example, if the parcel does not match the sorting machine trolley when it is transported to the sorting machine, the parcel will be disturbed during the movement of the sorting trolley, resulting in errors when the parcel is running or when it is packed after sorting.

[0005] At the same time, the existing automatic package loading method does not evaluate the status of the sorting cart coupled with the package, which may easily cause the package to enter the faulty sorting cart, thereby causing sorting errors; this greatly increases the timeliness of maintenance requirements when some carts of the sorting machine fail, which increases the maintenance cost of the sorting equipment. Summary of the invention

[0006] The object of the present invention is to provide an automatic packing method for a narrow-band sorting machine.

[0007] The present invention provides an automatic packing method for a narrow-band sorting machine, wherein a light curtain sensor is provided on a packing platform; the packing platform tilts from the side to the packing area of ​​the sorting machine to feed the parcel; the packing method comprises the following steps:

[0008] Step 1: Place the package on the upper packaging platform; the upper packaging platform drives the package to pass through the light curtain sensor at a uniform speed; a plane rectangular coordinate system is established with the length direction of the light curtain sensor as the X-axis and the conveying direction of the upper packaging platform as the Y-axis;

[0009] Step 2: After the package has completely passed through the light curtain sensor, the coordinates of the center point of the occupied area of ​​the package are constructed based on the detection results of the light curtain sensor ( x c ,y c ) and length L1; the area occupied by the package is the circumscribed rectangle of the package; the length side of the occupied area is parallel to the moving direction of the sorting cart in the upper package area.

[0010] Step 3: Calculate the remaining transport distance of the package L s , the distance between the actual packaging point and the starting point of the package L a as follows:

[0011] L s =L '- y c +x c / tan i

[0012] L a = x c / sin i

[0013] in, L ' is the starting point for loading the package on the sorting machine Y Axis coordinates: The starting point of the sorter loading is the intersection of the moving centerline of the sorting trolley and the Y axis of the plane rectangular coordinate system. θ is the angle between the conveying direction of the loading platform and the moving direction of the sorting trolley in the loading area.

[0014] Step 4: Determine the remaining transport distance of the package L s , match the package to the target car queue.

[0015] Step 5: By adjusting the delivery speed of the package, the speed of the package is matched with that of the target car queue, so that the center point of the occupied area of ​​the package and the center point of the target car queue arrive at the actual package point at the same time.

[0016] As a preferred embodiment, the process of step 4 is as follows:

[0017] Step 4-1. Determine the number of sorting carts in the target cart queue n as follows:

[0018]

[0019] in, P is the pitch of the sorting trolley.

[0020] Step 4-2. Calculate the standard distance L b The expression is as follows:

[0021]

[0022] Step 4-3. Based on standard distance L b Determine the first sorting trolley in the target trolley queue and obtain the target trolley queue.

[0023] As a preferred method, the specific process of obtaining the target car queue in step 4-3 is as follows: the distance from the center point to the starting point of the package is closest to the standard distance L b The sorting cart of is taken as the first candidate sorting cart; the sorting carts arranged in sequence starting from the first candidate sorting cart are selected. n The candidate trolley queue is composed of sorting trolleys. If all sorting trolleys in the candidate trolley queue are fault-free, the candidate trolley queue is used as the target trolley queue. Otherwise, the next sorting trolley after the last faulty sorting trolley in the candidate trolley queue is used as the first candidate sorting trolley and the candidate trolley queue is re-determined until the target trolley queue is obtained.

[0024] As a preferred method, the upper package travel distance of the target vehicle queue determined in step 4 L c The expression is as follows:

[0025]

[0026] in, is the distance from the center of the first sorting cart in the target cart queue to the starting point of the package loading. P is the pitch of the sorting trolley.

[0027] As a preferred embodiment, the specific process of step five is as follows:

[0028] Step 5-1. According to the delivery speed of the package v s Real-time update of remaining bag delivery distance L s ; According to the moving speed of the sorting cart v c Real-time update of the travel distance of the package L c ; Adjust the delivery speed of the package v s , until the remaining bag conveying distance L s Distance from upper package L c The following relationship is satisfied:

[0029]

[0030] Step 5-2. Increase the delivery speed of the package v s Adjust to , until the package enters the target car queue.

[0031] Preferably, the method for adjusting the delivery speed of the package in step 5-1 is: , then reduce the package delivery speed v s ; , then increase the package delivery speed v s .

[0032] Preferably, when the target trolley queue conveys the parcel to the target grid opening on the sorting machine, the conveyor belts of the sorting trolleys on the target trolley queue move simultaneously to convey the parcel into the target grid opening.

[0033] Preferably, the packaging platform comprises a package placing section, a conveying section and a packaging section which are connected in sequence; and there is only one package on the conveying section and the packaging section at the same time.

[0034] Preferably, when a sorting machine failure occurs, the bag placing section, the conveying section and the bag loading section reverse for a preset time and then stop moving.

[0035] As a preferred embodiment, the specific process of obtaining the occupied area in step 2 is as follows:

[0036] Step 2-1. Construct a plane rectangular coordinate system with the y-axis direction parallel to the conveying direction of the upper packaging platform; while the package passes through the light curtain sensor, continuously collect the coordinates of the contour points of the package.

[0037] Step 2-2. Calculate the intercepts b1 and b2 of the two straight lines y=x·tan(θ-90°)+b1 and y=x·tanθ+b2 when they are tangent to the package contour, and get a total of four solution values ​​b 1max 、b 1min 、b 2max 、b 2min θ is the angle between the loading platform and the moving direction of the sorting trolley in the loading area.

[0038] Step 2-3. Calculate the length L1 and width L2 of the occupied area of ​​the package as follows:

[0039] L 1=( b 1max - b 1min )×sin i

[0040] L 2=(b 2max - b 2min )×sin(90°- i )

[0041] Solve the coordinates of the center point of the occupied area according to the following set of equations ( x c , y c ):

[0042]

[0043] The present invention has the following beneficial effects:

[0044] The present invention uses the coordinates of the four extreme points of the package measured by the light curtain sensor to solve the length, width and center point coordinates of the circumscribed rectangle of the package with the length side parallel to the travel direction of the trolley; the center point coordinates can determine the actual packaging point of the package on the sorting machine; the length of the circumscribed rectangle can help determine the number of trolleys in the target trolley queue; thereby, the best target trolley queue can be comprehensively obtained, and the speed of the package and the target trolley queue can be matched more accurately, ensuring that the package can be automatically and accurately loaded.

[0045] When selecting the target trolley queue, the present invention determines whether the sorting trolley involved has a fault, so that the package automatically avoids the sorting trolley with the fault, avoiding the package from being damaged or falling off due to the fault of the sorting trolley or affecting the stable transportation of other packages on the sorting machine, thereby improving the accuracy of the sorting machine in sorting packages; and, the present invention enables the sorting machine to continue to stably perform sorting operations when some of the sorting trolleys fail, thereby improving the adaptability of the sorting machine to complex and high-intensity operations; and reducing the risk of unexpected downtime and maintenance costs of the sorting machine.

[0046] The present invention uses a circumscribed rectangle whose length side is parallel to the traveling direction of the trolley as the occupied area of ​​the package, so that the outline of the occupied area of ​​the package matches the outline of the sorting trolley, which is conducive to the accurate fitting of the package and the sorting trolley and greatly improves the accuracy of loading irregular packages. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] Figure 1 It is a flow chart of the present invention.

[0048] Figure 2 It is a top view schematic diagram of the bag loading platform and the bag loading area of ​​the narrow-band sorting machine used in the present invention. DETAILED DESCRIPTION

[0049] The present invention will be further described below in conjunction with the accompanying drawings.

[0050] like Figure 1As shown, an automatic packing method for a narrow-band sorting machine is used to select a sorting vehicle queue and load packs for a narrow-band cross-belt sorting machine. Figure 2 As shown, the packing platform used in the packing method includes a packing section 1, a conveying section 2 and a packing section 3 connected in sequence. The packing section 3 is composed of a plurality of conveyor belts arranged side by side and whose lengths increase in sequence along the arrangement direction. The ends of the conveyor belts are arranged in a straight line parallel to the travel direction of the sorting trolley 5. The conveying direction of the packing platform forms a certain angle with the travel direction of the sorting trolley. The packing section 1, the conveying section and the packing section 3 can all transport packages. A light curtain sensor 4 is provided between the packing section 1 and the conveying section. A camera or a barcode scanner is provided on the packing section 1.

[0051] In this embodiment, the pitch of the narrow-band sorting trolley is 200 mm to 300 mm.

[0052] The packaging method comprises the following steps:

[0053] Step 1: Turn on the power of the sorter and initialize the parameters of the sorter. Start the sorter and make the package placing section 1, the conveying section and the package loading section 3 move at a constant speed. Place the package on the front end of the package placing section 1; the package placing section 1 sends the package to the conveying section; the camera or barcode scanner collects and caches the package data, and the package passes through the light curtain sensor 4 at a constant speed. Before the package has completely passed the light curtain sensor 4, the package placing section 1 is prohibited from feeding other packages. In some embodiments, the package data includes barcodes, volumes, and pictures.

[0054] Step 2: After the package has completely passed through the light curtain sensor 4, a circumscribed rectangle of the package is constructed according to the detection result of the light curtain sensor 4. The length side of the obtained circumscribed rectangle is parallel to the moving direction of the sorting trolley in the sorting machine loading area.

[0055] In some embodiments, the specific process of obtaining the circumscribed rectangle is as follows:

[0056] 2-1. Establish the linear equations y=x·tan(θ-90°)+b1 and y=x·tanθ+b2 in the plane rectangular coordinate system; where θ is the angle between the conveying direction of the loading platform and the traveling direction of the sorting trolley in the loading area of ​​the sorting machine. b1 and b2 are the intercepts of the two linear equations, which are undetermined values ​​and are determined according to the shape and size of the package outline.

[0057] 2-2. When the package passes through the light curtain sensor 4, the contour points of the package are continuously collected. The package contour points are the two end points of the package interval detected by the light curtain sensor 4. The Y-axis coordinates of the package contour points are updated in real time according to the displacement of the conveyor belt. In the coordinates (x, y) of the package contour point, x is the detection value of the contour point by the light curtain sensor 4, and y is the displacement of the conveyor belt from the moment when the light curtain sensor 4 detects the contour point to the current moment.

[0058] 2-3. Use two straight line equations y=tan(θ-90°)x+b1 and y=tanθx+b2 to make the corresponding straight lines tangent to the package contour. The intercepts b1 and b2 of each straight line equation are obtained with two corresponding solution values, denoted as b 1max 、b 1min 、b 2max 、b 2min ; Some get four straight lines; the rectangle enclosed by the four straight lines is the circumscribed rectangle whose length side is parallel to the moving direction of the sorting trolley.

[0059] Calculate the length L1, width L2 and center point coordinates of the enclosed rectangle ( x c , y c ) is solved as follows:

[0060] L 1=( b 1max - b 1min )×sin i

[0061] L 2=( b 2max - b 2min )×sin(90°- i )

[0062]

[0063] Step 3: According to the center point coordinates of the enclosing rectangle ( x c , y c ) Calculate the remaining bag conveying distance L s as follows:

[0064] L s =L '- y c +x c / tan i

[0065] in, L ' is the Y-axis coordinate of the sorter loading starting point in the plane rectangular coordinate system; the sorter loading starting point is the intersection of the moving center line of the sorting trolley in the sorter loading area and the Y-axis of the plane rectangular coordinate system.

[0066] Calculate the distance traveled by the sorting cart between the actual packing point and the starting point of the package L a as follows:

[0067] L a = x c / sin i

[0068] Step 4: Match the package to the target vehicle queue. The specific process is as follows:

[0069] 4-1. Determine the number of sorting carts in the target cart queue n as follows:

[0070]

[0071] in, is the round-up symbol. P is the pitch of the sorting trolley.

[0072] 4-2. Calculate the standard distance L b The expression is as follows:

[0073]

[0074] 4-3. Traverse all sorting carts that have not matched goods before the starting point of the package (specifically, the sorting carts behind the target cart queue matched by the previous package), and take the distance from the center point to the starting point of the package that is closest to the standard distance L b The sorting cart of is taken as the first candidate sorting cart; the sorting carts arranged in sequence starting from the first candidate sorting cart are selected. n The sorting carts form a candidate cart queue.

[0075] If all the sorting carts in the candidate cart queue are normal, the candidate cart queue will be used as the target cart queue to match the package. Otherwise, the sorting cart after the last faulty sorting cart in the candidate cart queue will be used as the first candidate sorting cart and the candidate cart queue will be re-determined, and this cycle will be repeated until the target cart queue is obtained. Faults in sorting carts, such as failure of the electric roller causing the conveyor belt on the sorting cart to be unable to transport goods horizontally, etc. Whether the sorting cart is faulty can be determined by performing a fault self-check on the server of the sorting system. Collect the travel distance from the center point of the first sorting cart in the target cart queue to the starting point of the package. .

[0076] 4-4. Calculate the distance traveled by the target car queue L cas follows:

[0077] .

[0078] Among them, the travel distance of the package L c Specifically, it is the distance from the center point of the target car queue to the actual package point. It is the travel distance from the center point of the first sorting cart in the target cart queue to the starting point of loading the package.

[0079] Step 5: Match the speed of the package with the target vehicle queue.

[0080] 5-1. According to the delivery speed of the package v s Real-time update of remaining bag delivery distance L s ; According to the moving speed of the sorting cart v c Real-time update of the travel distance of the package L c ;

[0081] Adjust the package delivery speed until the remaining package delivery distance is reached L s Distance from upper package L c The following relationship is satisfied:

[0082]

[0083] The way to adjust the delivery speed of the package is: , then reduce the package delivery speed v s ; , then increase the package delivery speed v s .

[0084] 5-2. Adjust the delivery speed of the package v s , so that , the package is sent to the target car queue at a uniform speed, and the speed component of the package along the moving direction of the sorting car at the moment of loading is equal to the moving speed of the sorting car v c To prevent the parcel from sliding back and forth on the target trolley queue during loading.

[0085] When the target car queue delivers the package to the target grid, the conveyor belts of each sorting car on the target car queue move simultaneously to deliver the package to the target grid.

[0086] During the execution of the packing method, there is only one package in the packing section 3 at the same time; that is, the package after the package placing section 1 is sent to the conveying section only when the previous package leaves the conveying section; similarly, the package after the conveying section is sent to the packing section 3 only when the previous package leaves the packing section 3.

[0087] If there is a fault, the system will give a fault alarm and activate the reset button. The package placing section 1, conveying section and package loading section 3 will be forced to reverse for 1.5 seconds, clearing the fault, related data, and stopping related action instructions.

Claims

1. An automatic packing method for a narrow-band sorting machine, wherein a packing platform is provided with a light curtain sensor; the packing platform tilts from the side to the packing area of ​​the sorting machine to feed the parcel; the characteristics are: The packaging method comprises the following steps: Step 1: Place the package on the upper packaging platform; the upper packaging platform drives the package to pass through the light curtain sensor at a uniform speed; a plane rectangular coordinate system is established with the length direction of the light curtain sensor as the X-axis and the conveying direction of the upper packaging platform as the Y-axis; Step 2: After the package has completely passed through the light curtain sensor, the coordinates of the center point of the occupied area of ​​the package are constructed based on the detection results of the light curtain sensor ( x c , y c ) and length L1; the occupied area of ​​the package is the circumscribed rectangle of the package; the length side of the occupied area is parallel to the moving direction of the sorting trolley in the upper package area; Step 3: Calculate the remaining transport distance of the package L s , the distance between the actual packaging point and the starting point of the package L a as follows: L s =L '- y c +x c / tan θ L a = x c / sin θ in, L ' is the starting point for loading the package on the sorting machine Y Axis coordinates; the starting point of the sorting machine loading is the intersection of the moving center line of the sorting trolley and the Y axis of the plane rectangular coordinate system; θ is the angle between the conveying direction of the loading platform and the moving direction of the sorting trolley in the loading area; Step 4: Determine the remaining transport distance of the package L s , match the package to the target car queue; The process of step 4 is as follows: Step 4-1. Determine the number of sorting carts in the target cart queue n as follows: ； in, P is the pitch of the sorting trolley; Step 4-2. Calculate the standard distance L b The expression is as follows: ； Step 4-3. Based on standard distance L b Determine the first sorting trolley in the target trolley queue and obtain the target trolley queue; The specific process of the target car queue is as follows: take the distance from the center point to the starting point of the package that is closest to the standard distance L b The sorting cart of is taken as the first candidate sorting cart; the sorting carts arranged in sequence starting from the first candidate sorting cart are selected. n The candidate trolley queue is composed of sorting trolleys; if all the sorting trolleys in the candidate trolley queue are fault-free, the candidate trolley queue is used as the target trolley queue; otherwise, the next sorting trolley after the last faulty sorting trolley in the candidate trolley queue is used as the first candidate sorting trolley and the candidate trolley queue is re-determined until the target trolley queue is obtained; Step 5: By adjusting the delivery speed of the package, the speed of the package is matched with that of the target car queue, so that the center point of the occupied area of ​​the package and the center point of the target car queue arrive at the actual package point at the same time.

2. The automatic packing method for a narrow-band sorting machine according to claim 1, characterized in that: The package travel distance of the target car queue determined in step 4 L c The expression is as follows: ； in, is the distance from the center point of the first sorting trolley in the target trolley queue to the starting point of the package loading; P is the pitch of the sorting trolley.

3. The automatic packing method for a narrow-band sorting machine according to claim 2, characterized in that: The specific process of step five is as follows: Step 5-1. According to the delivery speed of the package v s Real-time update of remaining bag delivery distance L s ; According to the moving speed of the sorting cart v c Real-time update of the travel distance of the package L c ; Adjust the delivery speed of the package v s , until the remaining bag conveying distance L s Distance from upper package L c The following relationship is satisfied: ； Step 5-2. Increase the delivery speed of the package v s Adjust to , until the package enters the target car queue.

4. The automatic packing method for a narrow-band sorting machine according to claim 3, characterized in that: The method for adjusting the package delivery speed in step 5-1 is: , then reduce the package delivery speed v s ; , then increase the package delivery speed v s .

5. The automatic packing method for a narrow-band sorting machine according to claim 1, characterized in that: When the target trolley queue delivers the parcel to the target slot on the sorting machine, the conveyor belts of each sorting trolley on the target trolley queue move simultaneously to deliver the parcel to the target slot.

6. The automatic packing method for a narrow-band sorting machine according to claim 1, characterized in that: The packaging platform comprises a package placing section, a conveying section and a packaging section which are connected in sequence; and only one package exists on the conveying section and the packaging section at the same time.

7. The automatic packing method for a narrow-band sorting machine according to claim 1, characterized in that: The specific process of obtaining the occupied area in step 2 is as follows: Step 2-1. Construct a plane rectangular coordinate system with the y-axis direction parallel to the conveying direction of the upper package platform; while the package passes through the light curtain sensor, continuously collect the coordinates of the contour points of the package; Step 2-2. Calculate the intercepts b1 and b2 of the two straight lines y=x·tan(θ-90°)+b1 and y=x·tanθ+b2 when they are tangent to the package contour, and get a total of four solution values ​​b 1max , b 1min , b 2max , b 2min ; θ is the angle between the loading platform and the moving direction of the sorting trolley in the loading area; Step 2-3. Calculate the length L1 and width L2 of the occupied area of ​​the package as follows: L 1=( b 1max - b 1min )×sin θ L 2=( b 2max - b 2min )×sin(90°- θ ) Solve the coordinates of the center point of the occupied area according to the following set of equations ( x c , y c ): 。 8. The automatic packing method for a narrow-band sorting machine according to claim 1, characterized in that: When a sorter failure occurs, the bag placing section, conveying section and bag loading section will reverse for a preset time and then stop moving.

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