CN112623592A

CN112623592A - Method for correcting relative error between AGV and tray and AGV

Info

Publication number: CN112623592A
Application number: CN202011581202.1A
Authority: CN
Inventors: 刘瑞; 王忠岐; 卢振威
Original assignee: Keda Industrial Group Co Ltd
Current assignee: Keda Industrial Group Co Ltd
Priority date: 2020-12-28
Filing date: 2020-12-28
Publication date: 2021-04-09

Abstract

The invention provides a method for correcting relative errors of an AGV and a tray and the AGV, wherein the method comprises the following steps: step 1: presetting a corrected goods position point B and a temporary storage point A, and storing the position information of the corrected goods position point B and the temporary storage point A in an AGV controller; the distance between the corrected goods position point B and the temporary storage point A is a correction distance on the Y axis, and the temporary storage point A is arranged on a track from the AGV to the corrected goods position point B; step 2: the AGV controller controls the AGV to go to the temporary storage point A and puts down the tray; and step 3: and the AGV controller controls the AGV to go to a corrected goods position point B and acquires the tray. According to the method for setting the temporary storage point in advance, the AGV firstly stores the tray at a relatively close position, then moves to a relatively far correction goods position point to take off the tray, and the deviation distance between the tray and the AGV is eliminated.

Description

Method for correcting relative error between AGV and tray and AGV

Technical Field

The invention relates to the technical field of storage management systems, in particular to a method for correcting relative errors between an AGV and a tray and the AGV.

Background

The AGV is an important part of the smart storage, and has a high degree of automation and more uncertainty compared to other non-mobile devices. The AGV has a relatively strict requirement on the position of taking and placing the goods. Although the AGV is subjected to a complicated calibration test of physical parameters before leaving the factory, due to various reasons (e.g., machining errors, relative errors in positioning between vehicles, jolts caused by uneven ground at a customer site, circulation of trays in the system, etc.), errors are always present and accumulated in practice.

In order to eliminate the relative error between the AGV and the goods, the method of the general project at the present stage comprises the following steps: the method comprises the steps of adding a ground positioning pin, manufacturing a special tray correcting device, depending on visual positioning for correcting or increasing the positioning precision of the AGV and the like.

The ground positioning pin and the manufacturing tray correction equipment are added, correction is performed by a mechanical means, the cost is increased, intermediate links are generated, and the operation efficiency of the AGV is influenced. Depending on the vision positioning correction, the cost is higher, and the software algorithm has higher requirements on the performance of the equipment. And through the means, the positioning accuracy of the AGV is improved, and the error range of the AGV relative to the positioning point can only be reduced. And the skew of position inevitably takes place for the tray in placing and transportation, and the error that the skew produced can constantly increase after accumulational many times, directly influences AGV transport tray. The above approaches do not address the problem of relative errors between the AGV and the pallet.

Disclosure of Invention

The invention aims to provide a method for correcting relative errors between an AGV and a tray and the AGV.

In order to achieve the purpose, the technical scheme of the invention is as follows:

a method of correcting relative errors between an AGV and a pallet, the method comprising the steps of:

step 1: presetting a corrected goods position point and a temporary storage point, and storing the position information of the corrected goods position point and the temporary storage point in an AGV controller; the distance between the corrected goods position point and the temporary storage point is the correction distance on the Y axis, and the temporary storage point is arranged on the track from the AGV to the corrected goods position point;

step 2: the AGV controller controls the AGV to go to the temporary storage point and puts down the tray;

and step 3: and controlling the AGV to go to the corrected goods site by the AGV controller, and acquiring the tray.

According to the method for setting the temporary storage point in advance, the AGV firstly stores the tray at a relatively close position, then moves to a relatively far correction goods position point to take off the tray, namely, the tray is pushed towards the AGV for a certain distance on the AGV, and further the deviation distance between the tray and the AGV is eliminated.

Further, the correction distance is greater than the actual error distance between the pallet and the AGV car.

Further, the actual error distance is obtained from manual measurements.

Further, the steps 2 and 3 are executed when the AGV runs in the running track, wherein one of the empty cargo positions on the running track is used as the corrected cargo position.

Further, the steps 2 and 3 are executed after the AGV carries the empty pallet back to the warehouse, wherein the cargo space point in the warehouse is used as the corrected cargo space.

Further, be provided with X axle correction mechanism on the AGV, X axle correction mechanism links with AGV's climbing mechanism, works as when climbing mechanism jacks up, X axle correction mechanism starts in order to rectify tray and AGV relative error in X axle direction.

The invention also provides an AGV, which applies the method for correcting the relative error between the AGV and the tray, wherein the AGV comprises a back plate and a bearing vehicle body;

the bearing vehicle body is connected in front of the back plate, a cargo detection device is arranged on the back plate, and a jacking mechanism is arranged on the bearing vehicle body;

the AGV further comprises an X-axis correcting mechanism and a Y-axis correcting mechanism, wherein the X-axis correcting mechanism is arranged on the jacking mechanism;

the Y-axis correcting mechanism comprises an anti-collision stop block, and the anti-collision stop block is arranged on the back plate.

Further, X axle aligning gear sets up bear four angles of automobile body, X axle aligning gear includes the ejector pad that stretches out and draws back along the X axle direction, the ejector pad is used for propping up with the inboard of the supporting legs of tray.

Further, the ejector pad includes buffering portion, buffering portion sets up the side at the ejector pad, just the material of buffering portion is rubber or silica gel.

Furthermore, the X-axis correcting mechanism also comprises a roller, and the rolling plane of the roller is parallel to the X-axis direction; the roller is arranged on the jacking mechanism, and the top surface of the roller is higher than the upper surface of the jacking mechanism.

According to the method for setting the temporary storage point in advance, the AGV firstly stores the tray at a relatively close position, then moves to a relatively far correction goods position point to take off the tray, and the deviation distance between the tray and the AGV in the Y-axis direction is eliminated. While maintaining the relative position of the pallet and AGV in the X-axis direction during operation by the pushers. The AGV is safe and efficient, does not need to add an additional mechanical mechanism or vision recognition equipment for correction, and saves cost.

Drawings

The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this application, illustrate embodiment(s) of the invention and together with the description serve to explain the invention without limiting the invention. In the drawings:

FIG. 1 is a flowchart of a method of correcting relative errors of an AGV and a tray and an AGV of the present invention;

FIG. 2 is a schematic diagram of the operation of step 2 of the present invention;

FIG. 3 is a schematic diagram of the operation of step 3 of the present invention;

FIG. 4 is a partial schematic view of an AGV of the present invention.

The automatic loading and unloading device comprises an AGV (automatic guided vehicle), a pallet, a back plate, a bearing vehicle body, a pallet, 11, a back plate, 12, a loading vehicle body, 13, a cargo detection device, 14, a jacking mechanism, 15, an anti-collision stop block, 16, a push block, 17 and rollers.

Detailed Description

The technical solution provided by the present invention is explained in more detail below with reference to fig. 1-4.

As shown in fig. 1 to 3, the method of the present invention for correcting relative errors between an AGV and a pallet includes the steps of:

step 1: presetting a corrected goods position point B and a temporary storage point A, and storing the position information of the corrected goods position point B and the temporary storage point A in an AGV controller; the distance between the corrected goods position point B and the temporary storage point A is a correction distance on the Y axis, and the temporary storage point A is arranged on a track from the AGV to the corrected goods position point B;

step 2: the AGV controller controls the AGV to go to the temporary storage point A and puts down the tray 2;

and step 3: and the AGV controller controls the AGV to go to a corrected goods site B and acquires the tray 2.

In FIGS. 2 and 3, 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.

The inventor discovers in the use that after the AGV gets, puts the tray for a period of time between a plurality of goods position points, the tray is kept away from the AGV gradually, and when the tray was too far away from the AGV when certain AGV placed the tray at the goods position point, the AGV car was from the goods position point again when the tray, detection device on the AGV car could not detect the tray, and then the AGV car could not get the tray, led to the stall and reported to the police. Therefore, by the method of setting the temporary storage point A in advance, the AGV first stores the tray 2 at a relatively close position, then moves to the relatively far correction goods site B to take off the tray, namely, the tray 2 is pushed towards the AGV by a distance on the AGV, and further the deviation distance between the tray 2 and the AGV is eliminated.

After the positional deviation of the AGV and the tray is corrected, when the AGV continues to move to the next goods location to place the tray, the positional error of the tray on the goods location is smaller than the positional error of the tray which is not corrected.

In order to fully correct the position error of the AGV and the tray, the correction distance is greater than the actual error distance between the tray and the AGV. AGV deposits the tray in after the point of temporary storage A promptly, when going to correction goods position point B and getting goods, because the tray is too close to the AGV, can be impeld one section distance to continuing by the AGV when the tray shifts to on the AGV and touches the backplate of AGV, ensures that the enough backplate that is close to the AGV of tray, eliminates AGV and tray error in Y axle direction. Wherein, the AGV includes the backplate and bears the weight of the automobile body that bears of tray, it connects to bear the automobile body the rear of backplate. For convenience of understanding, d1 represents the actual error distance and d2 represents the correction distance in fig. 2.

According to the inventor's practical experience, when d2-d1<5mm, the positional error of the AGV and tray 2 can be sufficiently corrected without advancing tray 2 too far.

Wherein the actual error distance is obtained from a manual measurement.

In a storage automation system of a ceramic enterprise, an AGV generally starts from a warehouse, performs a series of pick-and-place actions according to a specified running track, and returns to the warehouse. The moving track is provided with a plurality of goods sites, wherein some goods sites need to place goods on the tray, and some goods sites do not need to place goods on the tray and serve as a temporary storage circulation point.

In the present embodiment, these cargo sites that do not require placing of cargo on the pallet are preferable as the correction cargo site B. When the step 3 is performed, the AGV needs to push the pallet 2 forward, if there is a cargo on the pallet 2, the friction between the pallet and the AGV is increased, and the cargo on the pallet 2 is easily damaged by collision, so that the step 2 and the step 3 should be performed by selecting an empty pallet.

For the case that there is no running track of the goods location where no goods need to be placed on the pallet, the steps 2 and 3 should be performed after the AGV carries the empty pallet back to the warehouse, wherein the goods location point in the warehouse is used as the corrected goods location to ensure that no goods are on the pallet when the steps 2 and 3 are performed.

Therefore, the AGV performs a correction once in a cycle of starting from the warehouse, performing a series of pick-and-place operations according to a predetermined travel trajectory, and returning to the warehouse. An operator only needs to measure the error distance between the tray and the AGV when the AGV runs to the corrected goods position B for the first time, and the actual error distance can be obtained.

Be provided with X axle correction mechanism on the AGV, X axle correction mechanism links with the climbing mechanism of AGV, works as when climbing mechanism jacks up, X axle correction mechanism starts in order to rectify tray and AGV relative error in X axle direction. The X-axis correction mechanism of the AGV is always kept in a starting state in the running process, so that the AGV is prevented from shifting in the X-axis direction due to road jolt or gradient and the tray in the running process.

The invention also provides an AGV, which applies the method for correcting the relative error between the AGV and the tray, and as shown in FIG. 4, the AGV comprises a back plate 11 and a bearing vehicle body 12; the bearing vehicle body 12 is connected in front of the back plate 11, a cargo detection device 13 is arranged on the back plate 11, and a jacking mechanism 14 is arranged on the bearing vehicle body 12; the AGV further comprises an X-axis correcting mechanism and a Y-axis correcting mechanism, wherein the X-axis correcting mechanism is arranged on the jacking mechanism; the Y-axis correction mechanism comprises an anti-collision stop block, and the anti-collision stop block 15 is arranged on the back plate 11.

The goods that the tray among the ceramic enterprise bore are mostly heavy goods such as ceramic tile, marble, and the tray generally is the steel construction, and hardness is big, weight is big. Since step 3 is performed, the AGV needs to push the tray 2 forward, and the anti-collision stopper 15 needs to be disposed on the back plate 11 to prevent the tray 2 from colliding with the back plate 11. The bump stop 15 is preferably rubber.

The X-axis correcting mechanism is arranged at four corners of the bearing vehicle body 12 and comprises a push block 16 which stretches along the X-axis direction, and the push block is used for abutting against the inner side of the supporting leg of the tray. When the jacking mechanism jacks 14, the pushing block 16 is pushed out of the bearing vehicle body 11 until the pushing block abuts against the four supporting legs of the tray 2. Due to the fact that the extending lengths of the push blocks 16 are consistent, the push blocks 16 push the tray 2 leftwards or rightwards by pushing supporting feet of the tray, and therefore the tray 2 is aligned with the bearing vehicle body 11.

The ejector pad includes buffering portion, buffering portion sets up the side at the ejector pad, just the material of buffering portion is rubber or silica gel. Buffering portion not only can play the cushioning effect when promoting the tray, and the frictional force between the supporting legs of buffering portion and tray still plays the effect of stabilizing the tray when the AGV operation. It should be noted that, in fig. 4, a schematic view of the buffer portion is not shown without affecting understanding.

The jacking mechanism 14 and the pushing block 16 are both pushed by an oil cylinder.

In order to reduce the friction between the tray 2 and the carrier vehicle body 12, the X-axis calibration mechanism further includes a roller 17, a rolling plane of the roller 17 is parallel to the X-axis direction, the roller 17 is disposed on the jacking mechanism 14, and a top surface of the roller 17 is higher than an upper surface of the jacking mechanism 14. In this embodiment, the front end and the rear end of the carrier vehicle body 12 are provided with the jacking mechanisms 14, and each of the two ends of the jacking mechanism 14 is provided with the roller 17, so that the sliding friction between the tray 2 and the jacking mechanism 14 is converted into the rolling friction between the tray 2 and the roller 17.

In the description of the present invention, it is to be understood that the terms "vertical", "lateral", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate orientations or positional relationships based on those shown in the drawings, and are used only for convenience in describing the present invention and for simplicity in description, and do not indicate or imply that the referenced devices or elements must have a particular orientation, be constructed and operated in a particular orientation, and thus, are not to be considered as limiting the scope of the present invention.

If the terms "first," "second," etc. are used herein to define parts, those skilled in the art will recognize that: the use of "first" and "second" is merely for convenience in describing the invention and to simplify the description, and the words are not intended to have a special meaning unless otherwise stated.

The present invention is not limited to the embodiments, and various modifications and variations of the present invention are intended to be included within the scope of the claims and the equivalent technical scope of the present invention if they do not depart from the spirit and scope of the present invention.

Claims

1. A method of correcting relative errors between an AGV and a pallet, the method comprising the steps of:

2. A method for correcting AGV to tray relative errors according to claim 1, characterised in that:

the correction distance is greater than the actual error distance between the pallet and the AGV car.

3. A method of correcting AGV to tray relative errors according to claim 2, characterised in that:

the actual error distance is obtained from manual measurements.

4. A method for correcting AGV to tray relative errors according to claim 1, characterised in that:

the steps 2 and 3 are executed when the AGV runs in the running track, wherein one of the empty cargo positions on the running track is used as the corrected cargo position.

5. A method for correcting AGV to tray relative errors according to claim 1, characterised in that:

and the step 2 and the step 3 are executed after the AGV carries the empty tray to return to the warehouse, wherein the goods position point in the warehouse is used as the corrected goods position.

6. A method for correcting AGV to tray relative errors according to claim 1, characterised in that:

be provided with X axle correction mechanism on the AGV, X axle correction mechanism links with the climbing mechanism of AGV, works as when climbing mechanism jacks up, X axle correction mechanism starts in order to rectify tray and AGV relative error in X axle direction.

7. An AGV, characterized in that: the AGV applying the method for correcting the relative error of the AGV and the tray according to any one of claims 1 to 6, wherein the AGV comprises a back plate and a bearing vehicle body;

8. The AGV of claim 7, wherein:

the X-axis correcting mechanism is arranged at four corners of the bearing vehicle body and comprises a push block which stretches along the X-axis direction, and the push block is used for abutting against the inner side of the supporting leg of the tray.

9. The AGV of claim 8, wherein:

the ejector pad includes buffering portion, buffering portion sets up the side at the ejector pad, just the material of buffering portion is rubber or silica gel.

10. The AGV of claim 7, wherein:

the X-axis correcting mechanism also comprises a roller, and the rolling plane of the roller is parallel to the X-axis direction;

the roller is arranged on the jacking mechanism, and the top surface of the roller is higher than the upper surface of the jacking mechanism.