A method for correcting relative error between AGV and pallet and AGV

Abstract

The present invention provides a method for correcting the relative error between an AGV and a pallet and an AGV, the method comprising the following steps: Step 1: pre-setting a correction cargo location point B and a temporary storage point A, and storing the position information of the correction cargo location point B and the temporary storage point A in an AGV controller; wherein the distance between the correction cargo location point B and the temporary storage point A is the correction distance on the Y axis, and the temporary storage point A is set on the trajectory of the AGV running to the correction cargo location point B; Step 2: the AGV controller controls the AGV to go to the temporary storage point A and put down the pallet; Step 3: the AGV controller controls the AGV to go to the correction cargo location point B and obtain the pallet. The present invention uses the method of setting the temporary storage point in advance, so that the AGV first stores the pallet at a relatively close position, and then moves to a relatively far correction cargo location point to take down the pallet, thereby eliminating the deviation distance between the pallet and the AGV.

Description

Technical Field

[0001] The present invention relates to the technical field of warehouse management systems, and in particular to a method for correcting a relative error between an AGV and a pallet and an AGV. Background Art

[0002] As an important part of smart warehousing, AGV has a high degree of automation, but compared with other non-mobile equipment, there are more uncertainties. AGV has more stringent requirements on the location of goods. Although AGV will undergo relatively complex physical parameter calibration tests before leaving the factory, due to various reasons (such as machining errors, relative positioning errors between vehicles, bumps caused by uneven ground at the customer's site, and the circulation of pallets in the system, etc.), errors always exist and have a certain degree of accumulation during actual implementation.

[0003] In order to eliminate the relative error between AGV and goods, the current general projects include: adding ground positioning pins, manufacturing special pallet correction equipment, relying on visual positioning correction or increasing the accuracy of AGV positioning, etc.

[0004] Among them, adding ground positioning pins and manufacturing pallet correction equipment are mechanical means of correction, which increases costs and creates intermediate links, affecting the operating efficiency of the AGV. Relying on visual positioning correction is costly and has high requirements for equipment performance and software algorithms. In addition, increasing the positioning accuracy of the AGV through the above means can only reduce the error range of the AGV relative positioning point. However, the position of the pallet will inevitably shift during placement and transportation, and the error caused by the shift will continue to increase after multiple accumulations, directly affecting the AGV's handling of the pallet. The above means do not solve the problem of relative error between the AGV and the pallet. Summary of the invention

[0005] The present invention aims to provide a method for correcting the relative error between an AGV and a pallet and an AGV, wherein the method and the AGV can solve the problem of an error between the AGV and the pallet during operation.

[0006] In order to achieve the above object, the technical solution of the present invention is:

[0007] A method for correcting the relative error between an AGV and a pallet, characterized in that the method comprises the following steps:

[0008] Step 1: pre-set a calibration cargo location and a temporary storage point, and store the position information of the calibration cargo location and the temporary storage point in the AGV controller; wherein the distance between the calibration cargo location and the temporary storage point is the calibration distance on the Y axis, and the temporary storage point is set on the trajectory of the AGV running to the calibration cargo location;

[0009] Step 2: The AGV controller controls the AGV to go to the temporary storage point and put down the pallet;

[0010] Step 3: The AGV controller controls the AGV to go to the correction cargo location and obtain the pallet.

[0011] The present invention sets a temporary storage point in advance, so that the AGV first stores the pallet at a relatively close position, and then moves to a relatively far correction cargo position to take down the pallet, which is equivalent to pushing the pallet on the AGV towards the AGV for a distance, thereby eliminating the deviation distance between the pallet and the AGV.

[0012] Furthermore, the correction distance is greater than an actual error distance between the pallet and the AGV vehicle.

[0013] Furthermore, the actual error distance is obtained according to manual measurement.

[0014] Furthermore, step 2 and step 3 are performed when the AGV is running within the running track, wherein one of the empty cargo location points on the running track serves as the correction cargo location point.

[0015] Furthermore, step 2 and step 3 are performed after the AGV returns to the warehouse with the empty pallet, wherein the cargo location in the warehouse serves as the correction cargo location.

[0016] Furthermore, the AGV is provided with an X-axis correction mechanism, which is linked to the lifting mechanism of the AGV. When the lifting mechanism is lifted, the X-axis correction mechanism is activated to correct the relative error between the pallet and the AGV in the X-axis direction.

[0017] The present invention also provides an AGV, the AGV applying the above-mentioned method for correcting the relative error between the AGV and the pallet, the AGV comprising a back plate and a carrying body;

[0018] The load-bearing vehicle body is connected to the front of the back plate, a cargo detection device is provided on the back plate, and a lifting mechanism is provided on the load-bearing vehicle body;

[0019] The AGV further comprises an X-axis correction mechanism and a Y-axis correction mechanism, wherein the X-axis correction mechanism is arranged on the lifting mechanism;

[0020] The Y-axis correction mechanism comprises an anti-collision block, and the anti-collision block is arranged on the back plate.

[0021] Furthermore, the X-axis correction mechanism is arranged at the four corners of the carrier body, and the X-axis correction mechanism includes a push block that is telescopic along the X-axis direction, and the push block is used to abut against the inner side of the support foot of the pallet.

[0022] Furthermore, the push block includes a buffer portion, the buffer portion is arranged on a side of the push block, and the material of the buffer portion is rubber or silicone.

[0023] Furthermore, the X-axis correction mechanism also includes a roller, the rolling plane of the roller is parallel to the X-axis direction; the roller is arranged on the lifting mechanism, and the top surface of the roller is higher than the upper surface of the lifting mechanism.

[0024] The present invention sets a temporary storage point in advance, so that the AGV first stores the pallet at a relatively close position, and then moves to a relatively far calibration cargo point to take the pallet, thereby eliminating the deviation distance between the pallet and the AGV in the Y-axis direction. At the same time, the relative position of the pallet and the AGV in the X-axis direction is maintained by a push block during operation. The AGV of the present invention is safe and efficient, and does not require additional mechanical mechanisms or visual recognition equipment for calibration, thus saving costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The drawings described herein are used to provide a further understanding of the present invention and constitute a part of this application. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0026] Figure 1 A method for correcting the relative error between an AGV and a pallet and a flow chart of the AGV of the present invention;

[0027] Figure 2 It is a schematic diagram of the operation of step 2 of the present invention;

[0028] Figure 3 It is a schematic diagram of the operation of step 3 of the present invention;

[0029] Figure 4 It is a partial schematic diagram of the AGV of the present invention.

[0030] Among them, 1. AGV, 2. pallet, 11. back plate, 12. load-bearing vehicle body, 13. cargo detection device, 14. lifting mechanism, 15. anti-collision block, 16. push block, 17. roller. DETAILED DESCRIPTION

[0031] Combine the following Figure 1-4 The technical solution provided by the present invention is described in more detail.

[0032] like Figures 1 to 3 As shown, the method of correcting the relative error between the AGV and the pallet of the present invention is characterized in that the method comprises the following steps:

[0033] Step 1: pre-set the calibration cargo point B and temporary storage point A, and store the position information of the calibration cargo point B and temporary storage point A in the AGV controller; wherein the distance between the calibration cargo point B and the temporary storage point A is the calibration distance on the Y axis, and the temporary storage point A is set on the track of the AGV running to the calibration cargo point B;

[0034] Step 2: The AGV controller controls the AGV to go to temporary storage point A and put down tray 2;

[0035] Step 3: The AGV controller controls the AGV to go to the correction cargo location B and obtain the pallet 2.

[0036] exist Figure 2 and Figure 3 In the figure, the Y-axis direction is the front and rear direction of the AGV; the X-axis direction is the left and right direction of the AGV.

[0037] The inventor found during use that after the AGV has been picking up and placing pallets between multiple cargo locations for a period of time, the pallets gradually move away from the AGV, until the AGV places the pallet at a cargo location one time, and the pallet is too far away from the AGV, causing the AGV to pick up the pallet from the cargo location again. The detection device on the AGV cannot detect the pallet, and then the AGV cannot pick up the pallet, causing it to stop running and alarm. Therefore, the present invention sets a temporary storage point A in advance, so that the AGV first stores the pallet 2 at a relatively close position, and then moves to the relatively far calibration cargo location B to take the pallet, which is equivalent to pushing the pallet 2 on the AGV towards the AGV for a distance, thereby eliminating the deviation distance between the pallet 2 and the AGV.

[0038] After the position deviation of the AGV and the pallet is corrected, when the AGV continues to run to the next cargo location to place the pallet, the position error of the pallet at the cargo location is smaller than the position error of the uncorrected pallet.

[0039] In order to fully correct the position error between the AGV and the pallet, the correction distance is greater than the actual error distance between the pallet and the AGV. That is, after the AGV stores the pallet at the temporary storage point A, when it goes to the correction storage point B to pick up the goods, because the pallet is too close to the AGV, when the pallet is transferred to the AGV and touches the back plate of the AGV, it will be pushed forward by the AGV for a distance to ensure that the pallet is close enough to the back plate of the AGV to eliminate the error between the AGV and the pallet in the Y-axis direction. Among them, the AGV includes a back plate and a carrier body for carrying the pallet, and the carrier body is connected to the rear of the back plate. For easy understanding, Figure 2 Where d1 represents the actual error distance, and d2 represents the correction distance.

[0040] According to the actual experience of the inventors, when d2-d1<5 mm, the position error between the AGV and the tray 2 can be fully corrected without pushing the tray 2 too far.

[0041] Wherein, the actual error distance is obtained according to manual measurement.

[0042] In the warehouse automation system of ceramic enterprises, AGV generally starts from the warehouse, performs a series of pick-up and put-down actions according to the prescribed running track, and then returns to the warehouse. Among them, multiple cargo points are set on the running track, some of which need to place goods on pallets, and some cargo points do not need to place goods on pallets, and serve as a temporary storage transfer point.

[0043] In this embodiment, the cargo spots where no cargo is required to be placed on the pallet are preferably used as the correction cargo spots B. When performing step 3, the AGV needs to push the pallet 2 forward. If there are cargo on the pallet 2, the friction between the pallet and the AGV will increase, and the cargo on the pallet 2 will be easily damaged. Therefore, an empty pallet should be selected to perform steps 2 and 3.

[0044] In the case where there is no running trajectory for a cargo location where goods do not need to be placed on the pallet, steps 2 and 3 should be performed after the AGV returns to the warehouse with an empty pallet, wherein the cargo location in the warehouse serves as the correction cargo location to ensure that there is no goods on the pallet when performing steps 2 and 3.

[0045] Therefore, when the AGV starts from the warehouse, performs a series of pick-up and drop-off actions according to the specified running track, and then returns to the warehouse, it will be calibrated once. The operator only needs to measure the error distance between the pallet and the AGV when the AGV first runs to the calibration cargo point B to obtain the actual error distance.

[0046] The AGV is provided with an X-axis correction mechanism, which is linked to the AGV's lifting mechanism. When the lifting mechanism is lifted, the X-axis correction mechanism is activated to correct the relative error between the pallet and the AGV in the X-axis direction. That is, the X-axis correction mechanism is always kept activated during the operation of the AGV to prevent the AGV from shifting in the X-axis direction with the pallet due to bumps or slopes on the road during driving.

[0047] The present invention also provides an AGV, wherein the AGV applies the above-mentioned method for correcting the relative error between the AGV and the pallet, such as Figure 4As shown, the AGV includes a back plate 11 and a carrying body 12; the carrying body 12 is connected to the front of the back plate 11, a cargo detection device 13 is provided on the back plate 11, and a lifting mechanism 14 is provided on the carrying body 12; the AGV also includes an X-axis correction mechanism and a Y-axis correction mechanism, the X-axis correction mechanism is provided on the lifting mechanism; the Y-axis correction mechanism includes an anti-collision block, and the anti-collision block 15 is provided on the back plate 11.

[0048] The goods carried by pallets in ceramic enterprises are mostly heavy goods such as tiles and marble. Pallets are generally made of steel structures with high hardness and weight. Since the AGV needs to push the pallet 2 forward during step 3, it is necessary to set the anti-collision block 15 on the back plate 11 to prevent the pallet 2 from colliding with the back plate 11. The anti-collision block 15 is preferably made of rubber.

[0049] The X-axis correction mechanism is arranged at the four corners of the carrier body 12, and includes a push block 16 that is telescopic along the X-axis direction, and the push block is used to abut against the inner side of the support legs of the pallet. When the jacking mechanism 14 is lifted, the push block 16 is pushed outward from the carrier body 11 until it abuts against the four support legs of the pallet 2. Since the extension length of the push block 16 is consistent, the push block 16 pushes the pallet 2 to the left or right by pushing the support legs of the pallet, thereby aligning the pallet 2 with the carrier body 11.

[0050] The push block includes a buffer portion, which is arranged on the side of the push block and is made of rubber or silicone. The buffer portion not only acts as a buffer when pushing the pallet, but the friction between the buffer portion and the supporting feet of the pallet also acts to stabilize the pallet when the AGV is running. It should be noted that without affecting understanding, the attached Figure 4 A schematic diagram of the buffer portion is not shown.

[0051] Wherein, the lifting mechanism 14 and the pushing block 16 are both pushed by oil cylinders.

[0052] In order to reduce the friction between the tray 2 and the carrier body 12, the X-axis correction mechanism further includes a roller 17, the rolling plane of the roller 17 is parallel to the X-axis direction, the roller 17 is arranged on the lifting mechanism 14, and the top surface of the roller 17 is higher than the upper surface of the lifting mechanism 14. In this embodiment, the lifting mechanism 14 is arranged at both the front and rear ends of the carrier body 12, and the rollers 17 are arranged at both ends of each lifting mechanism 14, so that the sliding friction between the tray 2 and the lifting mechanism 14 is converted into rolling friction between the tray 2 and the rollers 17.

[0053] In the description of the present invention, it is necessary to understand that the terms "vertical", "lateral", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship are based on the orientation or position relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the protection content of the present invention.

[0054] If the words "first", "second", etc. are used in this document to limit components, those skilled in the art should know that the use of "first" and "second" is only to facilitate the description of the present invention and simplify the description. Unless otherwise stated, the words have no special meaning.

[0055] The present invention is not limited to the described embodiments. If various changes or modifications to the present invention do not depart from the spirit and scope of the present invention, and if these changes and modifications fall within the scope of the claims and equivalent technologies of the present invention, the present invention is also intended to include these changes and modifications.

Claims

1. A method for correcting the relative error between an AGV and a pallet, characterized in that: The method comprises the following steps: Step 1: pre-set a calibration cargo point and a temporary storage point, and store the position information of the calibration cargo point and the temporary storage point in the AGV controller; wherein the distance between the calibration cargo point and the temporary storage point is the calibration distance on the Y axis, and the temporary storage point is set on the trajectory of the AGV running to the calibration cargo point; the calibration distance is greater than the actual error distance between the pallet and the AGV vehicle; Step 2: The AGV controller controls the AGV to go to the temporary storage point and put down the pallet; Step 3: The AGV controller controls the AGV to go to the calibration cargo location and obtain the pallet; The steps 2 and 3 are performed when the AGV is running within the running track, wherein one of the empty cargo location points on the running track serves as the correction cargo location point.

2. The method for correcting the relative error between the AGV and the pallet according to claim 1, characterized in that: The actual error distance is obtained according to manual measurement.

3. The method for correcting the relative error between the AGV and the pallet according to claim 1, characterized in that: The steps 2 and 3 are performed after the AGV returns to the warehouse with the empty pallet, wherein the cargo location in the warehouse serves as the correction cargo location.

4. The method for correcting the relative error between the AGV and the pallet according to claim 1, characterized in that: The AGV is provided with an X-axis correction mechanism, which is linked with the lifting mechanism of the AGV. When the lifting mechanism is lifted, the X-axis correction mechanism is activated to correct the relative error between the pallet and the AGV in the X-axis direction.

5. An AGV, characterized in that: The AGV applies the method for correcting the relative error between the AGV and the pallet as described in any one of claims 1 to 4, and the AGV includes a back plate and a carrying body; The load-bearing vehicle body is connected to the front of the back plate, a cargo detection device is provided on the back plate, and a lifting mechanism is provided on the load-bearing vehicle body; The AGV further comprises an X-axis correction mechanism and a Y-axis correction mechanism, wherein the X-axis correction mechanism is arranged on the lifting mechanism; The Y-axis correction mechanism comprises an anti-collision block, and the anti-collision block is arranged on the back plate.

6. The AGV according to claim 5, characterized in that: The X-axis correction mechanism is arranged at the four corners of the carrier body, and the X-axis correction mechanism includes a push block that is telescopic along the X-axis direction, and the push block is used to abut against the inner side of the support foot of the tray.

7. The AGV according to claim 6, characterized in that: The push block comprises a buffer portion, the buffer portion is arranged on the side of the push block, and the material of the buffer portion is rubber or silicone.

8. The AGV according to claim 5, characterized in that: The X-axis correction mechanism also includes a roller, and the rolling plane of the roller is parallel to the X-axis direction; The roller is arranged on the lifting mechanism, and the top surface of the roller is higher than the upper surface of the lifting mechanism.

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