Goods Position Verification Method Based on Visual Positioning and Stacker

Abstract

The present disclosure belongs to the technical field of warehouse logistics, and particularly relates to a method and a stacker for verifying the position of goods based on visual positioning, including: obtaining the current position of a warehouse stacker based on visual positioning; obtaining the target goods number of the goods position to determine the target goods position of the warehouse stacker; planning the moving path of the warehouse stacker based on the current position and the target goods position of the warehouse stacker; determining whether the warehouse stacker reaches the target goods position; when the warehouse stacker reaches the target goods position, verifying whether the goods at the target goods position are the target goods to complete the movement of the goods.

Description

Technical Field

[0001] The present disclosure belongs to the technical field of warehouse logistics, and particularly relates to a method for verifying the position of goods based on visual positioning and a stacker crane. Background Art

[0002] The statements in this part merely provide background technical information related to the present disclosure and do not necessarily constitute prior art.

[0003] With the rapid development of the economy, the circulation of goods is getting faster and faster, and the development of logistics warehousing technology is also becoming more and more rapid. Traditional manual warehouses can no longer meet the needs of modern warehousing, and logistics stacker crane warehouses with high transportation rates and high space utilization rates have gradually been widely sought after by enterprises.

[0004] The number of storage positions on each floor of the stacker crane warehouse aisle is usually over a hundred, and the aisle length is usually over dozens of meters. During the debugging process, each storage position requires manual operation of the stacker crane by personnel to align, which is time-consuming and laborious; the walking motor of the stacker crane is a servo motor. During the process of rapid acceleration and rapid deceleration, the driving wheel will slightly slip on the track, and the data recorded by the encoder on the servo motor will deviate from the actual walking distance, resulting in inaccurate positioning. After the positioning deviates, the controller will enter the fault mode and cannot execute normal tasks, requiring personnel to handle it, with low operating efficiency.

[0005] According to the inventor's understanding, the existing logistics stacker cranes have the following problems: during debugging, personnel need to manually operate the stacker crane to walk for each shelf positioning, which takes a long time to debug for large warehouses, and is highly dangerous and inefficient; when the stacker crane executes tasks, the positioning accuracy is low, often unable to align with the storage position correctly, requiring manual correction by personnel, with a high failure rate and low reliability; when picking up or placing goods, the stacker crane cannot verify whether the goods are correct, resulting in a low storage accuracy rate. Summary of the Invention

[0006] To solve the above problems, the present disclosure proposes a method for verifying the position of goods based on visual positioning and a stacker crane, which has the functions of self-learning and self-correcting the shelf position, can reduce the debugging time during the normal process of picking up and placing goods, make the walking positioning more accurate, self-check the correctness of the goods, make the access more efficient, improve the production operation efficiency, and reduce the operation failure rate.

[0007] According to some embodiments, the first solution of the present disclosure provides a method for verifying the position of goods based on visual positioning, and adopts the following technical solution:

[0008] A method for verifying the position of goods based on visual positioning, comprising:

[0009] Obtaining the current position of the warehouse stacker crane based on visual positioning;

[0010] Obtain the target goods number for the location of the goods, and determine the target goods location of the warehousing stacker;

[0011] Based on the current location and the target goods location of the warehousing stacker, plan the movement path of the warehousing stacker;

[0012] Judge whether the warehousing stacker has reached the target goods location;

[0013] When the warehousing stacker reaches the target goods location, verify whether the goods at the target goods location are the target goods, and complete the picking or placing of the goods.

[0014] As a further technical limitation, in the process of obtaining the current location of the warehousing stacker based on visual positioning, a vision sensor is used to collect the goods location at the location of the warehousing stacker to determine the current location of the warehousing stacker.

[0015] As a further technical limitation, the process of planning the movement path of the warehousing stacker based on the current location and the target goods location of the warehousing stacker includes determining the traveling position and the lifting position of the warehousing stacker according to the current location and the target goods location of the warehousing stacker, and planning the movement path of the warehousing stacker.

[0016] Specifically, the traveling position of the warehousing stacker refers to the position change of the warehousing stacker in the horizontal direction, and the lifting position of the warehousing stacker refers to the position change of the warehousing stacker in the vertical direction. Further, before judging whether the warehousing stacker has reached the target picking location, according to the planned movement path of the warehousing stacker, the traveling driver and the lifting driver inside the warehousing stacker act successively to complete the movement of the warehousing stacker in position.

[0017] As a further technical limitation, when the warehousing stacker reaches the target goods location, the process of verifying whether the goods at the target goods location are the target goods is as follows: when the warehousing stacker reaches the target goods location, combine the vision sensor to obtain the goods number at the target goods location, and judge whether the obtained goods number is the target goods number.

[0018] Further, in the process of judging whether the obtained goods number is the target goods number, obtain the picture of the goods number at the target goods location, compare the obtained picture of the goods number with the pre-stored preset picture of the goods number that meets the goods accuracy requirements, judge whether the accuracy of the obtained picture of the goods number at the target goods location meets the goods accuracy requirements. If it meets, directly judge that the obtained goods number is the target goods number; otherwise, perform adaptive adjustment of the warehousing stacker position according to the obtained picture of the goods location number, and update the adjusted warehousing stacker position to realize the adaptive learning of the warehousing stacker position.

[0019] Further, in the process of determining whether the accuracy of the picture of the goods number at the obtained target goods position meets the accuracy requirements of the goods, by comparing the position of the outer frame of the goods location number in the imaging of the obtained picture of the goods number, it is determined whether the obtained goods number meets the accuracy requirements of the goods; the accuracy requirements of the goods mean that in the picture of the goods number at the obtained target goods position, the outer edge of the outer frame of the goods location number does not exceed ±0.5% of the edge of the entire picture.

[0020] Further, in the process of adaptive learning of the position of the warehousing stacker, it is not necessary to calibrate the position coordinates of the goods. Based on the vision sensor, visual positioning of the goods is performed, and according to the obtained goods location number, combined with the control mechanism, adaptive learning of the position of the warehousing stacker is completed.

[0021] Specifically, the warehousing stacker is internally provided with a controller for controlling the lifting of the lifting platform and an actuator for executing the lifting of the lifting platform, and these both belong to the control mechanism of the warehousing stacker.

[0022] As a further technical limitation, when the warehousing stacker reaches the target goods position, based on the vision sensor, a photo check of the goods number is performed to verify whether there is a target goods at the target goods position. After confirmation, the warehousing stacker executes the task of picking up or placing goods.

[0023] According to some embodiments, the second solution of the present disclosure provides a stacker for executing the method for verifying the position of goods based on visual positioning provided in the first solution, and adopts the following technical solution:

[0024] A stacker,

[0025] including a warehousing stacker and a lifting platform provided on the warehousing stacker;

[0026] The lifting platform is vertically arranged on the warehousing stacker, and vision sensors are arranged on both sides thereof.

[0027] As a further technical limitation, the stacker further includes a pallet fork provided on the lifting platform for placing goods.

[0028] Compared with the prior art, the beneficial effects of the present disclosure are as follows:

[0029] The present disclosure solves the problems of difficult and inefficient picking up or placing goods in the prior art. Based on visual positioning, the acquisition of the target goods number, the planning of the goods path of the warehousing stacker, and the picking up of goods are carried out. It has the functions of self-learning and self-correction of the shelf position, can reduce the debugging time in the normal process of picking up and placing goods, make the walking positioning more accurate, self-check the correctness of the goods, and the access is more efficient, improve the production operation efficiency, and reduce the operation failure rate. Description of the Drawings

[0030] The accompanying drawings forming a part of this disclosure are used to provide a further understanding of the disclosure. The schematic embodiments and descriptions thereof of the disclosure are used to explain the disclosure and do not constitute an improper limitation of the disclosure.

[0031] Figure 1 is a flowchart of the method for verifying the position of goods based on visual positioning in the first embodiment of the disclosure;

[0032] Figure 2 is a schematic diagram of the goods number in the first embodiment of the disclosure;

[0033] Figure 3 is a schematic structural diagram of the stacker in the second embodiment of the disclosure;

[0034] Among them, 1. Warehouse stacker, 2. Vision sensor, 3. Lifting platform, 4. Plate fork, 5. Shelf. Detailed implementation manners

[0035] The disclosure will be further described below in conjunction with the accompanying drawings and embodiments.

[0036] It should be noted that the following detailed descriptions are all illustrative and are intended to provide a further description of the disclosure. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the technical field to which the disclosure belongs.

[0037] It should be noted that the terms used herein are only for describing specific implementation manners and are not intended to limit the exemplary implementation manners according to the disclosure. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0038] Without conflict, the embodiments in the disclosure and the features in the embodiments can be combined with each other.

[0039] Embodiment 1

[0040] Embodiment 1 of the disclosure introduces a method for verifying the position of goods based on visual positioning.

[0041] As Figure 1 shown. A method for verifying the position of goods based on visual positioning includes:

[0042] Step S01: Obtain the current position of the warehouse stacker based on visual positioning; obtain the target goods number of the goods position, and determine the target goods position of the warehouse stacker;

[0043] Step S02: Plan the moving path of the storage stacker based on the current position of the storage stacker and the target cargo position;

[0044] Step S03: Determine whether the storage stacker has reached the target cargo position;

[0045] Step S04: When the storage stacker reaches the target cargo position, verify whether there is the target cargo at the target cargo position, and complete the picking or placing of the cargo.

[0046] As one or more embodiments, in Step S01, the stacker can determine its current traveling position and lifting position by detecting the numbers on the storage locations using a vision sensor (specifically, since the numbers on the storage locations at different positions on the shelf are different, that is, the numbers on the storage locations can uniquely represent different positions on the shelf, so the position of the stacker, namely its traveling position and lifting position, can be determined by detecting the numbers on the storage locations); in the traditional stacker, both traveling and lifting are driven by servo motors. The controller of the stacker will record the current cargo position of the stacker. After receiving the task coordinates, the stacker can calculate the distances for traveling and lifting. The accuracy of each travel of the stacker is within ±5 mm. There is no way to verify the position before and after traveling, and the positioning completely relies on the reliability of the servo, resulting in cumulative errors and inaccurate positions over time. The current solution is that the stacker returns to the origin (origin coordinates 0, 0) regularly to verify the position through sensors. On the one hand, it is time-consuming, and on the other hand, there is no verification of the position before and after performing the task, posing a great risk; when moving goods, if the position is not verified, there is a possibility that the lifting position of the lifting platform of the stacker is not at the cargo position on the shelf. At this time, the fork is at the middle position of the cargo or the position of the shelf, which will cause the fork to directly insert into the cargo or the fork to insert into the shelf, resulting in damage to the cargo or the fork.

[0047] In this embodiment, the schematic diagram of the cargo numbers is as Figure 2 shown, and a detailed introduction is given taking the target cargo 000244825 as an example:

[0048] Obtain the current position of the stacker based on the vision sensor on the stacker; obtain the storage location number corresponding to the target goods 000244825, and the storage location number can be obtained as 0305, that is, the storage location number of the target goods position of the stacker is 0305; according to the obtained current position of the stacker and the target goods position, plan and determine the moving path of the warehouse stacker according to the controller and actuator inside the stacker; under the action of servo drive, realize the walking of the horizontal position of the stacker and the lifting and lowering of the vertical position of the lifting platform; the stacker first walks according to the planned goods path to the shelf position of the target goods, and then performs the lifting and lowering of the lifting platform position; during the lifting and lowering of the lifting platform, judge whether the lifting platform reaches the target goods position through the vision sensor. After reaching the target goods position, that is, reaching the position with the storage location number of 0305, the movement of the goods 000244825 is completed.

[0049] The moving process of the target goods at other positions is exactly the same as that of the target goods 000244825 with the storage location number of 0305, and will not be elaborated here.

[0050] In this embodiment, the vision stacker also uses servo drive technology. The difference is that the controller does not have to record the coordinates of the goods after the last task execution. Before executing the task, use vision technology to take a photo of the storage location number, and judge the position of the stacker at which goods through the storage location number.

[0051] As one or more implementation manners, in step S02, the upper computer issues task coordinates, the controller extracts the target goods position, compares it with the current position, and after calculation, the driving distances of walking and lifting can be known. The walking driver and the lifting driver execute simultaneously, and the approximate position of the target can be reached.

[0052] As one or more implementation manners, in step S03, the vision judges whether the target position is reached and uses vision for final positioning; after the stacker reaches the approximate position, the vision sensor takes a photo of the storage location number to check whether the storage location number is the target storage location number. At the same time, it is determined that the position meets the goods accuracy requirements when the outer frame of the storage location number is at a certain position in the picture (in this embodiment, it is set to not exceed ±0.5% of the outer frame edge), that is, a picture that meets the goods accuracy requirements is pre-stored in the processor of the vision sensor, and this picture is compared with the obtained picture. That is, compare the position of the outer frame of the storage location number in the imaging to determine whether the moving position of the stacker meets the goods accuracy requirements. If the goods accuracy requirements are not met, the position of the stacker is adaptively adjusted according to the picture, and the adjusted accurate position will be recorded and updated in the stacker controller to achieve the purpose of adaptive learning of the stacker.

[0053] As one or more embodiments, in step S04, after the stacker reaches the target position, it verifies whether the target goods are correct through a vision sensor. After the stacker reaches the approximate position, the vision sensor takes a photo of the storage location number. This photo is the same as the photo in step three. The target goods number is obtained from the photo, and this target goods number is verified with the target goods number in the warehouse management software. After confirmation, the stacker can perform the task of picking up or placing goods.

[0054] In addition, during the debugging phase of traditional stackers, it is necessary to calibrate each goods position, that is, obtain the coordinate values of each storage location, so that the stacker can obtain the driving distance for each task. For large warehouses, calibrating the coordinate values of each storage location is time-consuming and laborious; in this embodiment, it is not necessary to calibrate the coordinate values of the storage locations. It only needs to take pictures of the goods numbers under the action of the vision sensor, and adaptively adjust the position of the warehousing stacker according to the obtained pictures of the goods numbers, and update the position of the warehousing stacker after adjustment to achieve adaptive learning of the position of the warehousing stacker.

[0055] If due to external force, failure or at the start of debugging, the stacker is not at the goods moving position, that is, the stacker does not know where it is. At this time, the stacker can execute a program to find the coordinates of any nearby storage location. At this time, the stacker drives and lifts slowly, and one of the vision sensors on the left, right or middle starts the photo-taking function, continuously looking for and identifying the storage location number until any precise storage location number nearby is found. In particular, limit switches are installed at the extreme positions of the stacker's walking and lifting, so that no accidents will occur due to the execution of the coordinate search program.

[0056] In this embodiment, the stacker can determine the current walking and lifting position of the stacker by using a vision sensor to detect the number on the storage location. Even if the positioning deviates, the controller can perform secondary alignment through the self-correction function, improving the positioning accuracy and accuracy of the stacker; after the stacker reaches the target position, it verifies whether the bin is correct through the vision sensor, and then completes the goods moving operation. For the existing logistics stacker, it can effectively shorten the debugging time, reduce the debugging workload, reduce the positioning error of the stacker, improve the positioning accuracy, reduce the system error rate, and greatly improve the operation efficiency.

[0057] Embodiment Two

[0058] Embodiment Two of the present disclosure introduces a stacker.

[0059] As Figure 3A stacker as shown includes a warehousing stacker 1, a vision sensor 2, a lifting platform 3, and a fork 4 disposed on the warehousing stacker 1. Among them, the lifting platform 3 is vertically arranged on the warehousing stacker 1, and the lifting platform 3 can be lifted and lowered in the vertical position on the warehousing stacker 1. The vision sensors 2 are symmetrically arranged on both sides of the lifting platform 3. The fork 4 is placed on the lifting platform 3 and is lifted and lowered together with the lifting platform 3.

[0060] During the use process, the stacker is placed in the middle of adjacent shelves 5. The lifting platform 3 is lifted and lowered in the vertical direction. The vision sensors 2 arranged on both sides of the lifting platform 3 are used to identify whether there is a target cargo number at the current position. If the target cargo number cannot be identified by the vision sensors 2, the lifting and lowering of the lifting platform 3 need to continue until the target cargo number can be obtained and identified, and then the position lifting of the lifting platform 3 is stopped. After identifying the target cargo number, the target cargo position of the warehousing stacker 1 is determined. At this time, according to the position of the fork 4 on the warehousing stacker 1 and the identified target cargo position, the cargo path of the warehousing stacker 1 is planned. After planning the cargo path, the warehousing stacker 1 first moves horizontally. After reaching the horizontal position of the planned cargo path, the lifting platform 3 is lifted and lowered in the vertical direction, and then drives the fork 4 to be lifted and lowered. When reaching the vertical position of the planned cargo path, the lifting platform 3 stops lifting and lowering. At this time, the fork 4 extends to perform the cargo moving operation.

[0061] Although the specific embodiments of the present disclosure are described above in conjunction with the accompanying drawings, it is not a limitation on the protection scope of the present disclosure. Those skilled in the art should understand that based on the technical solutions of the present disclosure, various modifications or deformations that can be made without creative efforts by those skilled in the art are still within the protection scope of the present disclosure.

Claims

1. A method for verifying the position of goods based on visual positioning, characterized in that Including: Obtaining the current position of the storage stacker based on visual positioning; Obtaining the target location number of the goods location, and determining the target goods location of the storage stacker; Planning the movement path of the storage stacker based on the current position and the target goods location of the storage stacker; Judging whether the storage stacker reaches the target goods location; When the storage stacker reaches the target goods location, verifying whether there is a target good at the target goods location, and completing the task of picking up or putting down goods; When the storage stacker reaches the target goods location, the visual sensor takes a picture of the location number to obtain a location number picture, verifies the location number, compares the position of the outer frame of the location number picture in the imaging, and determines whether the movement position of the storage stacker meets the goods accuracy requirements; if it does not meet the goods accuracy requirements, adaptively adjust the position of the stacker, record and update the adjusted accurate position in the stacker controller, and complete the adaptive learning of the position of the storage stacker in combination with the control mechanism; The process of verifying whether there is a target good at the target goods location includes: obtaining the goods number picture at the target goods location from the location number picture, obtaining the target goods number from the goods number picture, and verifying it with the target goods number in the warehouse management software. After confirmation, the stacker can execute the task of picking up or putting down goods.

2. The method for verifying the position of goods based on visual positioning as described in claim 1, characterized in that In the process of obtaining the current position of the storage stacker based on visual positioning, a visual sensor is used to collect the goods position at the position of the storage stacker to determine the current position of the storage stacker.

3. A method for verifying the position of goods based on visual positioning as described in claim 1, characterized in that, In the process of planning the movement path of the storage stacker based on the current position and the target goods location of the storage stacker, it includes: determining the walking position and lifting position of the storage stacker according to the current position and the target goods location of the storage stacker, and planning the movement path of the storage stacker.

4. A method for verifying the position of goods based on visual positioning as described in claim 1, characterized in that The accuracy requirement for the goods means that in the picture of the storage location number at the obtained position of the target goods, the outer edge of the frame of the storage location number does not exceed the .

5. A stacker for executing the method for verifying the goods position based on visual positioning according to any one of claims 1-4, characterized in that It includes a storage stacker and a lifting platform arranged on the storage stacker; The lifting platform is arranged vertically on the storage stacker, and visual sensors are arranged on both sides thereof.

6. A stacker as described in claim 5, characterized in that, It further includes a fork plate arranged on the lifting platform for placing goods.

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