Transfer robot tray stacking method, electronic equipment and storage medium

Abstract

The invention provides a carrying robot tray stacking method, electronic equipment and a storage medium, and the method comprises the steps: responding to a tray stacking instruction, and dispatching a carrying trolley to carry empty trays; a target tray stacking position is selected, the tray stacking height or the number of layers is determined according to the current height or the number of layers of the target tray stacking position, and the carrying trolley is controlled to convey the empty trays to the target tray stacking position to be stacked; and if the carrying trolley responding to the later disc stacking instruction arrives at the target disc stacking station at the same disc stacking station, the disc stacking height or the number of layers of the carrying trolley which should arrive at present is exchanged to the carrying trolley which arrives at first. According to the method, the first-arriving carrying trolley puts down the empty tray to move first, and the situation that the first-arriving vehicle cannot place the empty tray and needs to carry the empty tray for waiting is prevented.

Description

Technical Field

[0001] This application relates to the technical field of warehousing equipment, and in particular, to a method for stacking pallets by a handling robot, an electronic device, and a storage medium. Background Art

[0002] AGV (Automated Guided Vehicles), also known as automated guided vehicle or laser guided vehicle, is characterized by driverless operation. It is equipped with an automatic guidance system, which can ensure that the system can automatically drive along a predetermined route without manual navigation and automatically transport goods or materials from the starting point to the destination.

[0003] In the prior art, goods are generally placed on pallets, and the AGV transports the goods by fork-lifting the pallets. However, during the frequent inbound and outbound processes of goods, many empty pallets will be generated. Especially during picking and outbound operations, as the goods are picked and placed into the order boxes for packing and outbound, many empty pallets will be scattered and randomly stacked. Summary of the Invention

[0004] In view of the above problems, this application provides a method for stacking pallets by a handling robot, an electronic device, and a storage medium, which can perform the task of stacking empty pallets during the gap of executing the handling task.

[0005] In a first aspect, this application provides a method for stacking pallets by a handling robot, which is used to stack empty pallets into a pallet stack. The method includes: In response to a pallet stacking instruction, dispatch a handling cart to transport an empty pallet; select a target pallet stacking position, determine the stacking height or number of layers according to the current height or number of layers of the target pallet stacking position, and control the handling cart to transport the empty pallet to be stacked to the target pallet stacking position for stacking; At the same pallet stacking position, if the handling cart responding to the subsequent pallet stacking instruction arrives at the target pallet stacking station first, exchange the stacking height or number of layers of the handling cart that should arrive currently with the handling cart that arrives first.

[0006] In one implementation, dispatching the handling cart to transport an empty pallet includes selecting an idle cart to transport the empty pallet. Select the idle cart with the shortest driving distance to the position of the empty pallet to be stacked as the target handling cart to transport the empty pallet.

[0007] In one implementation, dispatching the handling cart to transport an empty pallet includes selecting an idle cart to transport the empty pallet. If there are multiple idle trolleys, select one of the idle trolleys as the first idle trolley, and compare the driving distances of other idle trolleys to the empty pallet to be stacked. If there is a second idle trolley with a closer driving distance to the empty pallet to be stacked than the first idle trolley, then compare the driving distances of the remaining idle trolleys to the empty pallet to be stacked with the driving distance of the second idle trolley to the empty pallet to be stacked, until there is no idle trolley with a closer driving distance to the empty pallet to be stacked than the Nth idle trolley. Then select the Nth idle trolley as the target handling trolley to handle the empty pallet.

[0008] In one implementation, the selection of the target stacking position includes: Select the stacking position with the minimum current pallet height or number of layers for the stacking instruction as the target stacking position.

[0009] In one implementation, the selection of the target stacking position includes: Select the stacking position with the maximum current pallet height or number of layers for the stacking instruction as the target stacking position.

[0010] In one implementation, the current pallet height or number of layers includes the height or number of layers of the pallets already placed on the stacking position, or includes the stacking height or number of layers obtained by adding the height or number of layers in the stacking instruction with the stacking position as the target stacking position.

[0011] In one implementation, the pallet stacking method further includes: adding the height or number of layers of the pallet to be stacked in the stacking instruction to the target stacking position, and updating the current stacking height or number of layers of the target stacking position.

[0012] In one implementation, the method includes, after the handling trolley reaches the target stacking position, determining whether the actual occupancy situation on the stacking position matches the stacking height or number of layers of the handling trolley. If it matches, perform the stacking action; if it does not match, determine the handling trolley that should execute the stacking height or number of layers according to the actual occupancy situation of the target stacking position, and exchange the stacking heights or numbers of layers of the two handling trolleys.

[0013] In one implementation, the selection of the target stacking position includes: obtaining the height or number of layers of the pallet to be stacked in the stacking instruction, selecting the stacking position with the minimum or maximum current pallet height or number of layers for the stacking instruction as the target stacking position, and the target stacking position needs to satisfy that the current height or number of layers plus the height or number of layers of the pallet to be stacked in the stacking instruction does not exceed the preset height or number of layers of the stacking position.

[0014] In one implementation, the method includes exchanging the stack height or number of layers that the current arriving transfer cart should reach with the earlier arriving transfer cart, updating the current height or number of layers of this stack position, and updating the stack heights and numbers of layers of the remaining transfer carts that have not arrived based on the updated current height or number of layers of this stack position.

[0015] It is equivalent to exchanging the stack height or number of layers that the current arriving transfer cart should reach with the earlier arriving transfer cart, updating the current height or number of layers of this stack position. After that, after eliminating the task of the earlier arriving transfer cart, update all the remaining transfer carts that have not arrived. Here, the remaining transfer carts that have not arrived include the transfer cart that should arrive.

[0016] In one implementation, it includes: Exchanging the stack height or number of layers that the current arriving transfer cart should reach with the earlier arriving transfer cart, and the remaining transfer carts that have not arrived still follow the generation order of the stack commands as the arrival order. Based on the updated current height or number of layers of this stack position, sequentially update the stack heights and numbers of layers of the transfer carts; or, Exchanging the stack height or number of layers that the current arriving transfer cart should reach with the earlier arriving transfer cart, and returning the arrival order of the earlier arriving transfer cart to the current arriving transfer cart, while keeping the arrival orders of the other transfer carts unchanged.

[0017] Exchanging the stack height or number of layers that the current arriving transfer cart should reach with the earlier arriving transfer cart is equivalent to the stack command of the earlier arriving transfer cart being completed earlier than its original stack order. The remaining transfer carts that have not arrived still sequentially determine the arrival order according to the generation order of the stack commands, and sequentially update the stack heights and numbers of layers of the transfer carts; or, exchange the stack orders of the current arriving transfer cart and the earlier arriving transfer cart, while keeping the arrival orders of the other transfer carts that have not arrived unchanged.

[0018] In one implementation, exchanging the stack height or number of layers that the current arriving transfer cart should reach with the earlier arriving transfer cart includes: Exchanging the task orders of the current arriving transfer cart and the earlier arriving transfer cart, while keeping the arrival orders of the remaining transfer carts that have not arrived unchanged; the remaining transfer carts that have not arrived here do not include the current arriving transfer cart because the new arrival order of the current arriving cart has been determined, and its new arrival order is the original order of the earlier arriving transfer cart; Alternatively, the stack height or number of layers that should currently reach the handling trolley is exchanged with the handling trolley that arrives first, and the remaining handling trolleys that have not arrived yet still determine the order of arrival in sequence according to the generation order of the stack commands. The remaining handling trolleys that have not arrived here include the handling trolley that should currently arrive because only the stack order of the handling trolley that should currently arrive, that is, the stack height or number of layers, is given to the handling trolley that arrives first, and the handling trolley that should currently arrive is still the first handling trolley that should arrive after the handling trolley that arrives first stacks the trays. In principle, its order remains unchanged, but the handling trolley that arrives first cuts in front of it and completes the stacking.

[0019] In one implementation, the stacking position is provided with a preset height or number of layers. When the current stacking height or number of layers reaches the preset height or number of layers, this stacking position is set to a state where it cannot be used as a target stacking position. When the actual occupied height or number of layers of the stacking position that cannot be used as a target stacking position reaches the preset height or number of layers, the scheduling handling trolley moves the stacked pallet stack away from this stacking position, and this stacking position resumes the state of being available as a target stacking position.

[0020] A third aspect of the present application provides an electronic device, including: a processor, a storage medium, and a bus. The storage medium stores machine-readable instructions executable by the processor. When the electronic device runs, the processor communicates with the storage medium through the bus, and the processor executes the machine-readable instructions to perform the steps of the pallet handling method.

[0021] A fourth aspect of the present application provides a computer-readable storage medium, on which a computer program is stored. When the computer program is executed by a processor, the steps of the pallet handling method are implemented.

[0022] Beneficial effects: When responding to the stack command, the present application determines the stack height or number of layers according to the current height or number of layers of the target stacking position. Since tasks generated earlier often have a higher probability of arriving first, the present application determines the stack height or number of layers when responding to the stack command. Under normal circumstances, when tasks generated earlier arrive first, each handling trolley can quickly complete the action of placing the pallet when it reaches the stacking position and drive away from the stacking position, without having to wait for the upper system to issue the stack height or number of layers, nor upload the actual occupied height and number of layers of the stacking position detected after arrival to the upper system, and then further wait for the upper system to analyze the stack height or number of layers and then issue the stack height or number of layers command to this trolley, which makes the scheduling complex or the stacking efficiency not high.

[0023] When multiple handling carts simultaneously execute the pallet stacking task towards the same target pallet stacking position in this application, if the handling cart that responds to the subsequent pallet stacking instruction arrives at the target pallet stacking station first, the pallet stacking height or number of layers of the handling cart that should arrive currently will be exchanged with the handling cart that arrives first. This is to enable the handling cart that arrives first to put down the empty pallet and leave first, preventing the situation where the vehicle that arrives first cannot place the empty pallet and needs to wait while carrying the empty pallet. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] To describe the embodiments of the above and other features of the present invention, a more specific description of the present invention briefly described above will be presented with reference to the exemplary embodiments of the present invention shown in the accompanying drawings. It can be understood that these drawings only depict the exemplary embodiments of the present invention and should not be considered as limiting its scope. The present invention will be described and explained by using the drawings and additional features and details. In the drawings: Figure 1 is a flowchart of pallet stacking provided by this application; Figure 2 is a flowchart of the pallet stacking order for the same target pallet stacking position provided by this application; Figure 3 is a flowchart of a method for updating the pallet stacking order provided by this application; Figure 4 is a flowchart of the pallet stacking order exchange for the same target pallet stacking position provided by this application; Figure 5 is another flowchart of the pallet stacking order for the same target pallet stacking position provided by this application; DETAILED DESCRIPTION OF THE EMBODIMENTS

[0025] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings in the embodiments of this application. Obviously, the described embodiments are only some of the embodiments of this application, rather than all the embodiments. Usually, the components of the embodiments of this application described and shown in the drawings here can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of this application provided in the drawings is not intended to limit the scope of this application that is required to be protected, but only represents the selected embodiments of this application. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative efforts belong to the scope of protection of this application.

[0026] In the first aspect of this application, a method for a handling robot to stack pallets is disclosed, as Figure 1As shown, when an empty tray is generated, a tray stacking instruction will be generated accordingly. The tray stacking instruction includes the position information and quantity information of the empty tray. It is also possible to generate a tray stacking instruction for each empty tray. In this case, the tray stacking instruction includes the position information of the tray and does not necessarily include the quantity information of the tray, or the quantity information of the tray is always 1. In response to the tray stacking instruction, the scheduling and handling trolley is commanded to handle the empty tray. After generating the tray stacking instruction, an idle trolley is selected to handle the empty tray. First, check if there is an idle trolley. If there is no idle trolley, the tray stacking instruction is not executed. This allows for tray stacking during the intervals when the handling trolley is carrying out cargo handling tasks, maximizing the utilization of the handling trolley without affecting the execution of normal handling tasks. Additionally, there is no need to set up dedicated personnel or vehicles to handle the continuously scattered empty trays, saving manpower and vehicles. When there is only one idle trolley, that idle trolley executes the tray stacking task. When there are multiple idle trolleys, the idle trolley with the shortest driving distance to the position of the empty tray to be stacked is selected as the target handling trolley to handle the empty tray. It is necessary to first compare the driving distances of all idle trolleys to the position of the empty tray to be stacked and select the idle trolley with the shortest driving distance to execute the tray stacking task. It is also possible to select the trolley that takes the shortest time to reach the position of the empty tray to be stacked to execute the task. Generally, the trolley with the shortest driving distance also has the shortest driving time. When there are multiple idle trolleys, the target handling trolley for executing the tray stacking task can also be determined by means of traversal and comparison. Specifically, first select one of the idle trolleys as the first idle trolley and compare the driving distances of the other idle trolleys to the empty tray to be stacked. This comparison of the driving distances of the other idle trolleys to the empty tray to be stacked is carried out one by one, which can be in a certain order, such as in the order of vehicle serial numbers, or can be carried out one by one without any order. If, after the traversal comparison, no idle trolley closer to the empty tray to be stacked than the first idle trolley is found, then the first idle trolley is used as the target handling trolley to handle the empty tray. If a second idle trolley with a shorter driving distance than the first idle trolley appears, then the first idle trolley is eliminated, and the remaining idle trolleys are compared with the second idle trolley. If, after the traversal comparison, no idle trolley closer to the empty tray to be stacked than the second idle trolley is found, then the second idle trolley is used as the target handling trolley to handle the empty tray. If a third idle trolley with a shorter driving distance than the second idle trolley appears, then the second idle trolley is eliminated, and the remaining idle trolleys are compared one by one with the third idle trolley until no idle trolley with a shorter driving distance to the empty tray to be stacked than the Nth idle trolley is found, and then the Nth idle trolley is selected as the target handling trolley to handle the empty tray. Selecting the nearest idle trolley can improve the efficiency of tray stacking. When there are multiple tray stacking instructions, each tray stacking instruction selects the idle trolley with the shortest driving distance to the empty tray to be stacked to execute the task, which greatly improves the tray stacking efficiency and also helps the trolley to quickly complete the tray stacking task and then promptly receive the handling task, thereby enhancing the operating efficiency of the entire warehouse.

[0027] Select the target stacking position. When there is only one stacking position, this stacking position will always be the target stacking position. When there are multiple stacking positions, a selection needs to be made to select one of the multiple stacking positions as the target stacking position for the stacking task of this stacking instruction.

[0028] In one embodiment, select the stacking position with the smallest pallet height or number of layers as the target stacking position. This helps to balance the tasks of each stacking position and avoid a situation where when multiple handling vehicles perform stacking tasks with the same stacking position as the target stacking position, multiple vehicles reach the target stacking position and need to wait for the previous vehicle to complete stacking before the next vehicle can perform the stacking task, resulting in congestion and waiting of many vehicles. Specifically, the stacking position with the smallest height or number of layers of the pallets actually placed on the stacking position can be selected, or the stacking position with the smallest stacking height or number of layers obtained by adding the height or number of layers in the stacking instruction with this stacking position as the target stacking position can be selected.

[0029] In another embodiment, select the stacking position with the largest pallet height or number of layers as the target stacking position. This helps to quickly release the stacking position. By selecting the target stacking position based on the principle of filling one stacking position first, the number of stacking positions that can hold empty pallets can be kept at the maximum release in real time, and it is not easy to have a situation where multiple pallets are filled at the same time and there are only a few or no stacking positions available for stacking empty pallets. Because every time a stacking position is filled, the stacked empty pallet stack can be quickly transferred away from the stacking position to achieve the release of the stacking position. If the distribution is balanced among the stacking positions, it is very likely that multiple stacking positions will be filled at the same time, resulting in no or very few available stacking positions. Specifically, the stacking position with the largest height or number of layers of the pallets actually placed on the stacking position can be selected, or the stacking position with the largest stacking height or number of layers obtained by adding the height or number of layers in the stacking instruction with this stacking position as the target stacking position can be selected.

[0030] Determine the stacking height or number of layers according to the current height or number of layers of the target stacking position. Specifically, when there has been no stacking instruction bound to the target stacking position before this stacking instruction, that is, this stacking task is the first task for this stacking position, the current height or number of layers of the target stacking position is zero at this time, and the determined stacking height or number of layers is based on zero height and zero number of layers for stacking. After the target stacking position is selected, that is, this stacking instruction has been bound to the target stacking position, add the height or number of layers of the trays to be stacked in this stacking instruction to the target stacking position, and update the current stacking height or number of layers of the target stacking position for the next stacking instruction to obtain. When there has already been a stacking instruction bound to the target stacking position before this stacking instruction, for the sake of easy understanding, define the already bound stacking instruction as the first instruction, and define the above-mentioned stacking instruction that is about to be bound as the second instruction. At this time, the current height or number of layers of the target stacking position is the height or number of layers after adding the height or number of layers of the trays to be stacked in the first instruction to the target stacking position. Although sometimes when binding the second instruction, the empty trays of the first instruction have not yet been delivered to the stacking position or the stacking has not been completed, the current height or number of layers of the target stacking position is still the height or number of layers after adding the height or number of layers of the trays to be stacked in the first instruction to the target stacking position. For example, there are 4 empty trays that all need to be stacked on stacking position A. The first instruction: Tray 1 is stacked on the first layer above the zero layer; the second instruction: Tray 2 is stacked on the second layer; the third instruction: Tray 3 is stacked on the third layer; it is necessary to execute the fourth instruction to obtain the current height or number of layers of the target stacking position. Although it is possible that the empty trays of the second instruction and the third instruction have not yet reached the target stacking position, that is, at this time, the only empty tray that actually occupies the position at the target stacking position is the empty tray of the first instruction, then the current height or number of layers obtained for the target stacking position is still the height or number of layers after adding the third instruction, that is, the fourth instruction needs to be placed at the position of the fourth layer above the third layer. It is convenient for management and to obtain the stacking height of the stacking position in real time, preventing the situation where when multiple handling trolleys all use this stacking position as the target stacking position, due to not knowing the height after each instruction is completed, multiple handling trolleys that have bound multiple stacking instructions drive to the target stacking position, and the stacking is full or the height has reached the maximum upper limit value before all stacking is completed, resulting in congestion or the need to reselect the target stacking position.

[0031] If there is only one stacking instruction, then the handling cart corresponding to this one stacking instruction will stack at the target stacking position without any congestion or any complex situation. When there are a small number of stacking instructions and each stacking instruction can be docked with a different stacking position, that is, there is only one handling cart corresponding to each stacking instruction at the current stacking position stacking at the target stacking position, there will also be no congestion or any complex situation. However, in actual applications, there will be many stacking instructions and a limited number or a small number of stacking positions, that is, there will be a situation where multiple handling carts simultaneously perform stacking tasks to the same target stacking position.

[0032] As Figure 2 shown, when multiple handling carts simultaneously perform stacking tasks to the same target stacking position, if the handling cart responding to the later stacking instruction arrives at the target stacking workstation first, then exchange the stacking height or number of layers of the handling cart that should arrive currently with the handling cart that arrived first. In order to enable the handling cart that arrived first to put down the empty pallet and leave first, preventing the situation where the vehicle that arrived first cannot place the empty pallet and needs to wait while carrying the empty pallet.

[0033] Specifically, for the sake of easy understanding, the above situation is explained by way of example. For example, currently there are 4 empty pallets and 4 instructions are generated. All these 4 instructions need to be stacked on stacking position A. The first instruction: empty pallet 1 is stacked on the first layer above the zero layer; the second instruction: empty pallet 2 is stacked on the second layer; the third instruction: empty pallet 3 is stacked on the third layer; the fourth instruction: empty pallet 4 is stacked on the fourth layer. If the trolley carrying empty pallet 4 reaches stacking position A first, and at this time the trolleys carrying empty pallet 1, empty pallet 2, and empty pallet 3 have not reached stacking position A yet, then the trolley carrying empty pallet 4 belongs to the trolley for handling the stacking instruction that comes later, and the trolley carrying empty pallet 1 belongs to the trolley that should arrive currently. Then, the height or layer number of the first layer above the zero layer is returned to the trolley carrying empty pallet 4, that is to say, let the trolley carrying empty pallet 4 place empty pallet 4 on the first layer above the zero layer. In one embodiment, the height or layer number of the first layer above the zero layer is returned to the trolley carrying empty pallet 4, that is to say, let the trolley carrying empty pallet 4 place empty pallet 4 on the first layer above the zero layer. After that or simultaneously, the original stacking height or layer number of empty pallet 4 is exchanged with the trolley carrying empty pallet 1, that is to say, after the exchange, the stacking height or layer number of empty pallet 1 is stacked on the fourth layer. However, the specific stacking height or layer number of empty pallet 1 is subject to the time sequence of reaching the target stacking position. If after empty pallet 4 is placed on the first layer, immediately the trolley carrying empty pallet 1 reaches the target stacking position, and at this time the trolley carrying empty pallet 1 belongs to the trolley for handling the stacking instruction that comes later, and the trolley carrying empty pallet 2 belongs to the trolley that should arrive currently, then continue the exchange, let empty pallet 1 be placed on the second layer, and let empty pallet 2 be placed on the fourth layer, and so on, to perform the stacking operation.

[0034] In one of the embodiments, the pallet stacking method further includes confirming the actual occupancy status of the target stacking position after the transport cart arrives at the target stacking position, and determining whether the actual occupancy status of the stacking position matches the stacking height or number of layers of the transport cart. If the transport cart arrives at the target stacking position without first determining the actual occupancy status, when the transport cart places the pallet according to the stacking height or number of layers determined by the current height or number of layers of the target stacking position when the original stacking instruction is issued, the following two situations may occur. In the first situation, the transport cart arrives relatively early, and the carts of its previous stacking instruction have not arrived yet. At this time, the height or number of pallets on the stacking position have not reached the height or number of layers that the transport cart should be placed. The transport cart places the pallet according to its predetermined stacking height or number of layers. When placing pallets in layers, the pallets will fall from a high place, and it is very easy to cause the pallets to be tilted or fall, or the entire stack of empty pallets to collapse when they fall on the stacking position. In the second case, the transport cart arrives late, and many transport carts that were originally arranged behind it in the stacking order have already completed the stacking. At this time, the height or number of pallets on the stacking position is higher than the height or number of layers that the transport cart should be placed. When the transport cart places the pallets according to its predetermined stacking height or number of layers, it will push the stacked empty pallets away from the stacking position, causing the empty pallets to fall to the ground in a scattered manner.

[0035] Specifically, when the transport cart carries the pallets to be stacked to the target stacking position, it is necessary to first determine whether the actual occupancy on the stacking position is consistent with the stacking height or number of layers of the transport cart, and detect the actual occupancy on the target stacking position. The actual occupancy on the stacking position includes sensor detection or acquisition by the upper system; regarding sensor detection, the radar, camera and other sensors built into the vehicle body can be used to detect the height or number of layers of the stacked pallets on the target stacking position; the radar can detect the total height of the stacked pallets on the stacking position. When all the pallets are standard pallets with the same height, the number of pallet layers on the stacking position can also be further determined based on the total height and the height of a single pallet. If the stacking height is determined based on the height of the actual occupancy, there is no need to further confirm the number of layers. Ordinary cameras or depth cameras can determine the height or number of layers of the actual occupancy.

[0036] Regarding obtaining information from the upper-level system, for each transfer cart that executes the pallet stacking task, after transporting an empty pallet to the pallet stacking position and completing the pallet stacking, it uploads a task completion signal to the upper-level system. The upper-level system issues the actual occupancy situation of the pallet stacking position based on the task completion signal. For example: when the first transfer cart that needs to place the pallet on the first layer arrives at the pallet stacking position with an empty pallet and obtains a signal from the upper-level system indicating that the pallet stacking position is not occupied, it is considered that the first layer is exactly empty. The first transfer cart places the empty pallet on the first layer and further uploads the task completion signal. After receiving the task completion signal from the first cart, the upper-level system determines that the first layer of the pallet stacking position has been actually occupied. Then, the second transfer cart that needs to place the pallet on the second layer should be the next to arrive at the pallet stacking position. However, before the second cart reaches the pallet stacking position, the third cart that needs to place the pallet on the third layer arrives at the pallet stacking position first. At this time, the information obtained by the third cart from the upper-level system about the actual occupancy situation of the pallet stacking position is that the first layer has been occupied and the second layer has not been occupied. Since the pallets are stacked one by one, only the second layer can be stacked at the pallet stacking position at this time. There is a situation where the actual occupancy situation of the pallet stacking position does not match the stacking height or layer number of the third transfer cart that has arrived. The upper-level system queries that the transfer cart that should be placed on the second layer and is currently executing the task is the second cart, and asks the second cart that has not arrived to exchange the stacking height or layer number with the third cart that has arrived. That is, let the third cart that has arrived place the empty pallet on the second layer, and change the stacking height or layer number of the second cart that has not arrived to stack on the third layer. If the second cart arrives immediately after the third cart has placed the empty pallet, then the actual occupancy situation of the pallet stacking position matches the stacking height or layer number of the second cart, and the second cart executes the pallet stacking action. However, if the Nth cart arrives before the second cart, and at this time the actual occupancy situation of the pallet stacking position does not match the stacking height or layer number of the Nth cart, further exchanges are needed.

[0037] In the actual warehousing environment, during processes such as outbound, inbound, and picking, empty pallets are generally not generated all at once. For example, when the goods on a pallet are completely picked, an empty pallet that needs to be stacked is generated, and a stacking instruction is formed. The order in which the stacking instructions are generated is the same as the order in which the empty pallets are generated. Generally, empty pallets are generated one by one, but sometimes more than two empty pallets may appear simultaneously. For example, at the same picking station, multiple pallets are picked simultaneously and become empty pallets. To save space, these several empty pallets may be stacked together and wait for the handling cart to move them to the stacking position. In practical applications, for convenient scheduling, a stacking instruction can be formed for each empty pallet. Even if two already stacked empty pallets appear, two stacking instructions are respectively formed at this time, and two handling carts are respectively dispatched to perform the stacking task; alternatively, a stacking instruction can be generated for several already stacked empty pallets, and one handling cart is dispatched to move multiple stacked pallets to the stacking position at one time.

[0038] As Figure 3 shown, in one embodiment, after exchanging the stacking height or number of layers of the handling cart that should currently arrive at the stacking position to the handling cart that arrives first, the current height or number of layers of this stacking position is updated, and then the stacking heights and layers of the remaining handling carts are updated in sequence. The stacking heights and layers of the remaining handling carts are updated in sequence according to the updated current height or number of layers of this stacking position.

[0039] Generally speaking, the stacking order is the same as the order in which the tasks are generated. For example, when the first task is generated, if there is an idle cart, the idle cart will be immediately dispatched to pick up the empty pallet and quickly move the empty pallet to the stacking position for stacking. Therefore, in principle, for the tasks generated earlier, the probability of arriving at the stacking position first is also relatively high. So the stacking order of this application is determined according to the generation order of the stacking instructions. For the earlier stacking instructions, the corresponding empty pallets are placed below the target stacking position. That is to say, if sorted by digital serial numbers, the empty pallets of the stacking instructions with smaller serial numbers will be arranged below the empty pallets of the stacking instructions with larger serial numbers. The target stacking position is selected for each stacking instruction in sequence, and the stacking height or number of layers is determined. The quantity and number of layers of the empty pallets picked each time are different, which is conducive to reducing the number of trips of the handling cart. That is to say, when multiple pallets are generated simultaneously somewhere, one idle cart can be used to make one trip to move multiple generated empty pallets to the stacking position at one time.

[0040] The following is an example to illustrate how to update the stacking heights and layers of the subsequent handling carts. The following table shows the stacking instructions and the original order. In the actual working process, the order of arriving at the stacking position may be different from the original order.

[0041] Instruction sequence Number of pallets Number of layers to be placed Instruction 1 1 The first layer Instruction 2 2 The second layer Instruction 3 1 The fourth layer Instruction 4 3 The fifth layer For example, the actual arrival order is as follows: Instruction 1 arrives first, and the actual occupancy situation on the stacking position conforms to the stacking height or number of layers of the handling trolley, and the stacking action is completed; then Instruction 2 should arrive at the stacking position, but the trolley executing Instruction 4 arrives first. At this time, the number of layers that should be placed by Instruction 2 needs to be returned to Instruction 4, that is, the number of layers that should be placed by Instruction 4 is changed to the second layer. Instruction 4 includes 3 pallets. The actual situation of the updated stacking position is that the first layer is occupied by Instruction 1, and the second to fourth layers are occupied by Instruction 4. When another pallet arrives, it needs to be placed on the fifth layer.

[0042] There are two schemes for updating the stacking height and number of layers of the subsequent handling trolleys in sequence: The first one is equivalent to inserting the prematurely arrived Instruction 4 between Instruction 1 and Instruction 2, and other instructions still follow the original order of generation as their arrival order. The updated order and the number of layers to be placed are shown in the following table: Instruction sequence Number of pallets Number of layers to be placed Instruction 1 1 The first layer Instruction 4 3 The second layer Instruction 2 2 The fifth layer Instruction 3 1 The seventh layer The second one is equivalent to exchanging the order of the prematurely arrived Instruction 4 and the Instruction 2 that should arrive, and other instructions still follow the original order of generation as their arrival order. The updated order and the number of layers to be placed are shown in the following table: Instruction sequence Number of pallets Number of layers to be placed Instruction 1 1 The first layer Instruction 4 3 The second layer Instruction 3 1 The fifth layer Instruction 2 2 The sixth layer As Figure 4 - Figure 5 shown, in one embodiment, the height or number of layers of the pallets included in each stacking instruction is the same. When multiple handling trolleys simultaneously execute the stacking task towards the same target stacking position, if the handling trolley of the stacking instruction with a later response arrives at the target stacking station first, then the stacking height or number of layers of the currently arriving handling trolley is exchanged with the handling trolley that arrived first, including exchanging the task order between the currently arriving handling trolley and the handling trolley that arrived first. Specifically, since the height or number of layers of the pallets in each instruction is the same, the height or number of layers increased on the stacking position is the same for each stacking. When the handling trolley of the stacking instruction with a later response arrives at the stacking position first, only the task order between the currently arriving handling trolley and the handling trolley that arrived first needs to be exchanged. The following takes the example where each stacking instruction only includes one layer of pallet. The height or number of layers of the empty pallets taken and stacked each time is the same, making the stacking task easier to schedule. The stacking height or number of layers is in an equal proportion multiple of the height or number of layers of the empty pallets taken and stacked each time, which is easy to calculate. And when exchanging the stacking order, there is no need to calculate the height or number of layers, and the order and the stacking height or number of layers can be directly exchanged. The following example shows the situation where only one pallet is stacked each time. Specifically, two pallets can also be stacked each time, that is, a stacking instruction is generated when two empty pallets are produced, and an idle trolley is scheduled to pick up the empty pallets.

[0043] The order of instruction generation is shown in the following table: Instruction sequence Number of pallets Number of layers to be placed Instruction 1 1 The first layer Instruction 2 1 The second layer Instruction 3 1 The third layer Instruction 4 1 The fourth layer The actual arrival order is that the transfer cart for Instruction 1 arrives first and completes pallet stacking. Immediately following is the transfer cart for Instruction 4. In fact, the transfer cart that should arrive currently is for Instruction 2. It is possible to only exchange the execution order of Instruction 2 and Instruction 4, as shown in the following table: Instruction sequence Number of pallets Number of layers to be placed Instruction 1 1 The first layer Instruction 4 1 The second layer Instruction 3 1 The third layer Instruction 2 1 The fourth layer After Instruction 4 completes pallet stacking, if the transfer cart for Instruction 2 arrives at the pallet stacking position before the transfer cart for Instruction 3, at this time, it is necessary to continue to exchange the task order of Instruction 3 and Instruction 2.

[0044] Or, the pallet stacking height or number of layers of the transfer cart that should arrive currently is exchanged to the transfer cart that arrives first, and the remaining transfer carts that have not arrived still determine the arrival order in sequence according to the generation order of the pallet stacking instructions. As shown in the following table: Instruction sequence Number of pallets Number of layers to be placed Instruction 1 1 The first layer Instruction 4 1 The second layer Instruction 2 1 The third layer Instruction 3 1 The fourth layer It is equivalent to advancing the pallet stacking task of Instruction 4 before the pallet stacking task of Instruction 2.

[0045] The pallet stacking position is provided with a preset height or number of layers. When the pallet stacking height or number of layers reaches the preset height or number of layers, this pallet stacking position is set to the state of being unavailable as a target pallet stacking position. When the actual occupied height or number of layers of the pallet stacking position that is unavailable as a target pallet stacking position reaches the preset height or number of layers, the scheduling transfer cart moves the stacked pallet stack away from this pallet stacking position, and this pallet stacking position resumes the state of being available as a target pallet stacking position. Specifically, the height or number of layers of the empty pallets stacked on the pallet stacking position cannot be infinitely high or unlimited in number. Generally, the upper limit height or number of layers of the pallet stacking position can be set according to the lifting height of the transfer cart or considering the stability of transferring the empty pallet stack, or the upper limit height or number of layers of the pallet stacking position can also be set according to other factors such as the storage space for empty pallets. When the current pallet stacking height or number of layers reaches the preset height or number of layers, that is, when the Nth pallet stacking instruction selects the target pallet stacking position and adds the height or number of layers of the pallet to be stacked in the Nth pallet stacking instruction after the target pallet stacking position, and the height or number of layers of the pallets on the target pallet stacking position reaches the preset height or number of layers, then this pallet stacking position can no longer receive any empty pallets, even though it is possible that not all the transfer carts bound to this pallet stacking position have been delivered, that is, the actual occupancy situation on this pallet stacking position may not have reached the preset height or number of layers, this pallet stacking position still remains in the state of being unavailable as a target pallet stacking position and cannot receive any empty pallets. When all the transfer carts bound to this pallet stacking position have actually been delivered, at this time, the actual occupied height or number of layers of this pallet stacking position reaches the preset height or number of layers, so the scheduling transfer cart moves the stacked pallet stack away from this pallet stacking position, and this pallet stacking position resumes the state of being available as a target pallet stacking position. And update the current height and number of layers. Since the stacked ones have just been transferred away, at this time, the height of the empty pallets on this pallet stacking position is zero and the number of layers is zero.

[0046] The stacking position can be designated as any position in the storage warehouse. For the handling cart with QR code navigation, any QR code position can be selected as the stacking position. The pallet has four sides, and the handling cart can empty the pallet from four directions on the four sides of the pallet, or can also empty the pallet from two directions on the two opposite sides of the pallet. When emptying from two directions on the two opposite sides, it can ensure that the forkable directions of all pallets are the same. If emptying the pallet from four directions, then the forkable directions of the pallets on the stacked empty pallet stack will appear in the vertical direction. For example, for the pallets placed on the two intersecting sides of the pallet, their forkable directions are intersecting and perpendicular or almost perpendicular. According to actual needs, it is also possible to only allow emptying the pallet from 1 direction on one side of the pallet. Only allowing emptying the pallet from 1 direction on one side of the pallet, there will be no situation where multiple handling carts arrive at the same stacking position and place pallets simultaneously. If the stacking position allows emptying the pallet from directions on multiple sides of the pallet, when multiple handling carts arrive at different side directions simultaneously, the empty pallets will be placed in the order of generation of the stacking instructions. The stacking position does not specifically have any equipment or facilities, etc. It can be any empty area on the map, it can be a ground marked area, it can also be any area designated by the upper system in the system map, or it can be any QR code in the storage warehouse.

[0047] The second aspect of this application also discloses an electronic device, including: a processor, a storage medium, and a bus. The storage medium stores machine-readable instructions executable by the processor. When the electronic device runs, the processor communicates with the storage medium through the bus. The processor executes the machine-readable instructions to perform the steps of the pallet handling method.

[0048] The third aspect of this application also discloses a computer-readable storage medium, on which a computer program is stored. When the computer program is executed by a processor, the steps of the pallet handling method are implemented.

[0049] This application simultaneously sets a first detection component and a second detection component on the handling robot. The first detection component is set at the bottom of the chassis and can identify the ground pallet and can also identify the edge of the cross-shaped pallet, so that the picking component can be adjusted to accurately insert into the pallet jack; the second detection component can detect non-ground pallets. In the same device, it can both detect ground pallets and non-ground pallets, and can detect both cross-shaped pallets and channel-shaped pallets, improving the accuracy and compatibility of pallet detection.

[0050] Certainly, this application can also have many other embodiments. Without departing from the spirit and essence of this application, those skilled in the art can make various corresponding changes and deformations according to this application. However, these corresponding changes and deformations should all fall within the protection scope of the appended claims of this application.

Claims

1. A method for stacking pallets by a handling robot, which is used to stack empty pallets into a pallet stack, characterized in that, The method includes: In response to a pallet stacking instruction, scheduling a handling cart to carry an empty pallet; selecting a target pallet stacking position, determining the stacking height or number of layers according to the current height or number of layers of the target pallet stacking position, and controlling the handling cart to transport the empty pallet to be stacked to the target pallet stacking position for stacking; At the same pallet stacking position, if a handling cart responding to a subsequent pallet stacking instruction arrives at the target pallet stacking station first, exchange the stacking height or number of layers of the handling cart that should currently arrive with the handling cart that arrives first.

2. The method for a handling robot to stack pallets according to claim 1, wherein, Scheduling the handling cart to carry an empty pallet includes selecting an idle cart to carry the empty pallet, Selecting the idle cart with the shortest driving distance to the position of the empty pallet to be stacked as the target handling cart to carry the empty pallet.

3. The method for a handling robot to stack pallets according to claim 1, wherein, Scheduling the handling cart to carry an empty pallet includes selecting an idle cart to carry the empty pallet, If there are multiple idle carts, select one of the idle carts as the first idle cart, compare the driving distances of the other idle carts to the empty pallet to be stacked. If there is a second idle cart with a closer driving distance than the first idle cart, compare the driving distances of the remaining idle carts to the empty pallet to be stacked with the driving distance of the second idle cart to the empty pallet to be stacked until there is no idle cart with a closer driving distance than the Nth idle cart to the empty pallet to be stacked, and then select the Nth idle cart as the target handling cart to carry the empty pallet.

4. The method for a handling robot to stack pallets according to claim 1, wherein Selecting the target pallet stacking position includes: Selecting the pallet stacking position with the minimum current pallet height or number of layers for the pallet stacking instruction as the target pallet stacking position.

5. The method for a handling robot to stack pallets according to claim 1, characterized in that, Selecting the target pallet stacking position includes: Selecting the pallet stacking position with the maximum current pallet height or number of layers for the pallet stacking instruction as the target pallet stacking position.

6. The method for a handling robot to stack pallets according to claim 4 or 5, characterized in that, The current pallet height or number of layers includes the height or number of layers of the pallets already placed on the pallet stacking position, or includes the stacking height or number of layers obtained by adding the height or number of layers in the pallet stacking instruction with this pallet stacking position as the target pallet stacking position.

7. The method for a handling robot to stack pallets according to claim 1, wherein The pallet stacking method further includes: adding the height or number of layers of the pallet to be stacked in the pallet stacking instruction to the target pallet stacking position, and updating the current stacking height or number of layers of the target pallet stacking position.

8. The method for stacking pallets by a handling robot according to claim 1, characterized in that, The method includes, after the handling cart arrives at the target pallet stacking position, determining whether the actual occupancy situation on the pallet stacking position matches the stacking height or number of layers of the handling cart. If it matches, perform the stacking action; if it does not match, determine the handling cart that should execute the stacking height or number of layers according to the actual occupancy situation of the target pallet stacking position, and exchange the stacking heights or numbers of layers of the two handling carts.

9. The method for stacking pallets by a handling robot according to claim 1, wherein Selecting the target pallet stacking position includes: obtaining the height or number of layers of the pallet to be stacked in the pallet stacking instruction, selecting the pallet stacking position with the minimum or maximum current pallet height or number of layers for the pallet stacking instruction as the target pallet stacking position, and the target pallet stacking position needs to satisfy that the current height or number of layers plus the height or number of layers of the pallet to be stacked in the pallet stacking instruction does not exceed the preset height or number of layers of the pallet stacking position.

10. The method for a handling robot to stack pallets according to claim 1, characterized in that, The method includes exchanging the stacking height or number of layers of the handling cart that should currently arrive with the handling cart that arrives first, updating the current height or number of layers of this pallet stacking position, and updating the stacking heights and numbers of layers of the remaining handling carts that have not arrived according to the updated current height or number of layers of this pallet stacking position.

11. The method for stacking pallets by a handling robot according to claim 10, characterized in that, Includes: The stacking tray height or number of layers that should currently reach the handling cart is exchanged with the handling cart that arrives first. For the remaining handling carts that have not arrived, the order in which they should arrive remains the same as the order in which the stacking tray instructions are generated. Based on the current height or number of layers of this stacking tray position after the update, the stacking tray height and number of layers of the handling cart are updated in sequence; or, The stacking tray height or number of layers that should currently reach the handling cart is exchanged with the handling cart that arrives first, and the arrival order of the handling cart that arrives first is returned to the handling cart that should currently arrive, while the arrival orders of other handling carts remain unchanged.

12. The method for stacking pallets by the handling robot according to claim 1, wherein, Exchanging the stacking tray height or number of layers that should currently reach the handling cart with the handling cart that arrives first includes: The handling cart that should currently arrive exchanges the task order with the handling cart that arrives first, and the arrival orders of the remaining handling carts that have not arrived remain unchanged; or, The stacking tray height or number of layers that should currently reach the handling cart is exchanged with the handling cart that arrives first, and for the remaining handling carts that have not arrived, the arrival order is determined in sequence according to the order in which the stacking tray instructions are generated.

13. The method for a handling robot to stack pallets according to claim 1, wherein, The stacking tray position is provided with a preset height or number of layers. When the current stacking tray height or number of layers reaches the preset height or number of layers, this stacking tray position is set to the state of being unavailable as a target stacking tray position. When the actual occupied height or number of layers of the stacking tray position that is unavailable as a target stacking tray position reaches the preset height or number of layers, the scheduling handling cart moves the stacked pallet stack away from this stacking tray position, and this stacking tray position resumes the state of being available as a target stacking tray position.

14. An electronic device, characterized in that, Including: A processor, a storage medium, and a bus. The storage medium stores machine-readable instructions executable by the processor. When the electronic device runs, the processor communicates with the storage medium through the bus, and the processor executes the machine-readable instructions to perform the steps of the pallet stacking method for a handling robot as described in any one of claims 1-13.

15. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by the processor, it implements the steps of the pallet stacking method for a handling robot as described in any one of claims 1-13.

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