CN110989572A

CN110989572A - Accurate transfer control method suitable for AGV

Info

Publication number: CN110989572A
Application number: CN201911055752.7A
Authority: CN
Inventors: 林波
Original assignee: Chengdu Siwi High Tech Industrial Park Co Ltd
Current assignee: Chengdu Siwi High Tech Industrial Park Co Ltd
Priority date: 2019-10-31
Filing date: 2019-10-31
Publication date: 2020-04-10
Anticipated expiration: 2039-10-31
Also published as: CN110989572B

Abstract

The invention discloses an accurate transfer control method suitable for an AGV, wherein an image acquisition unit is arranged on the AGV with a conveying mechanism, a two-dimensional code is arranged at a target position, three-dimensional data of the two-dimensional code is read through the image acquisition unit, and deviation between the conveying mechanism and a butt joint conveying point is calculated through the three-dimensional data and is used as the transverse displacement of the conveying mechanism.

Description

Accurate transfer control method suitable for AGV

Technical Field

The invention relates to the technical field of unmanned transport, in particular to an accurate transfer control method suitable for an AGV.

Background

In the application of the AGV, for an unmanned transport vehicle which needs to be butted and conveys goods, in the motion process of the unmanned transport vehicle, a conveyor mechanism on the transport vehicle cannot be over against a receiving mechanism of a butt joint, so that the goods cannot be normally conveyed. Because the navigation and positioning technology is interfered by environment and has the precision defect, the technical requirement of the butt joint precision within 2mm is difficult to realize, and the conveying precision can not be ensured.

Disclosure of Invention

In order to solve the above problems, the present invention provides an accurate transfer control method suitable for an AGV.

Specifically, an image acquisition unit is arranged on an AGV carrier with a conveying mechanism, a two-dimensional code is arranged at a target position, three-dimensional data of the two-dimensional code is read through the image acquisition unit, and deviation between the conveying mechanism and a butt joint conveying point is calculated through the three-dimensional data and is used as the transverse displacement of the conveying mechanism.

Further, the three-dimensional data comprises a distance L between the image acquisition unit and the two-dimensional code along the conveying direction, a distance S between the image acquisition unit and the two-dimensional code, the distance S being perpendicular to the conveying direction, and an included angle theta between the right facing direction of the image acquisition unit and the conveying direction.

Further, the calculation formula of the transverse displacement amount is as follows: the amount of lateral displacement = S × cos θ + L × sin θ.

Furthermore, the AGV comprises a transporting vehicle body, and a transporting mechanism capable of moving horizontally is arranged on the transporting vehicle body.

Further, conveying mechanism include conveying mechanism A and conveying mechanism B, conveying mechanism A and conveying mechanism B all include two belt conveyor that set up side by side, and two belt conveyor pass through the link and link to each other, all are provided with the rack on conveying mechanism A's the link, rack and the gear engagement that is fixed in on the servo motor output shaft, and conveying mechanism A link and carrier body sliding connection.

Further, the carrier body on be provided with the slide rail, be provided with the slider on the link, be provided with the spout with slide rail looks adaptation on the slider.

Further, the conveying mechanism B is connected with the carrier body through a fixing frame, so that the conveying mechanism A and the conveying mechanism B are vertically distributed, a connecting frame of the conveying mechanism B is connected with the fixing frame in a sliding mode, and the conveying mechanism B is connected with the conveying mechanism A through a connecting rod.

Furthermore, two ends of the connecting rod are respectively fixed on the connecting frames of the conveying mechanism A and the conveying mechanism B.

Further, the belt conveyor device is provided with an infrared sensor for detecting the quantity of the transmitted goods.

The invention has the beneficial effects that: the two-dimensional code data can be used as error input in the design, so that the defect of low positioning accuracy of the AGV is overcome at low cost, and the AGV can be accurately conveyed.

Drawings

FIG. 1 is a left side view of the transport mechanism;

FIG. 2 is a front view of the transport mechanism;

FIG. 3 is a schematic structural view of the conveying mechanism A;

fig. 4 is a schematic diagram of establishing a coordinate system with a camera and a two-dimensional code as an origin;

FIG. 5 is a schematic view of the AGV transport mechanism facing the docking point relative to the docking point;

FIG. 6 is a schematic view of three-dimensional data acquired by an image acquisition unit;

FIG. 7 is a schematic illustration of an AGV after lateral displacement;

FIG. 8 is a schematic diagram of the calculation of the amount of lateral displacement;

in the figure, 1-a conveying mechanism A, 2-a conveying mechanism B, 3-a belt conveying device, 4-a connecting frame, 5-a rack, 6-a gear, 7-a sliding rail, 8-a sliding block, 9-a fixing frame, 10-a connecting rod, 11-an image acquisition unit and 12-a two-dimensional code.

Detailed Description

In order to more clearly understand the technical features, objects, and effects of the present invention, embodiments of the present invention will now be described with reference to the accompanying drawings.

An AGV includes a main body, as shown in fig. 1-3, which is provided with a conveying mechanism capable of moving horizontally. The conveying mechanism comprises a conveying mechanism A1 and a conveying mechanism B2, the conveying mechanism A1 and the conveying mechanism B respectively comprise two belt conveying devices 3 which are arranged in parallel, and the two belt conveying devices 3 are connected through a connecting frame 4, so that the carrier has 4 conveying channels for conveying goods. The connecting frames 4 of the conveying mechanism A are respectively provided with a rack 5, the racks 5 are meshed with a gear 6 fixed on an output shaft of the servo motor, and the connecting frames 4 of the conveying mechanism A1 are in sliding connection with the carrier body. Specifically, be provided with slide rail 7 on the carrier body, be provided with slider 8 on the link 4, be provided with the spout with 7 looks adaptations of slide rail on the slider 8. The servo motor rotates to drive the gear 6 to rotate, so that the connecting frame of the conveying device A1 moves left and right, and the two belt conveying devices 3 move horizontally. The conveying mechanism B2 is connected with the truck body through a fixed frame 9, so that the conveying mechanism A1 and the conveying mechanism B2 are vertically distributed and have an upper-layer conveying structure and a lower-layer conveying structure; the connecting frame 4 of the conveying mechanism B2 is connected with the fixing frame 9 in a sliding manner, specifically, a sliding rail is arranged on the fixing frame 9, a sliding block is arranged on the connecting frame of the conveying mechanism B, the sliding block is provided with a sliding groove, and the sliding rail is matched with the sliding groove. The conveying mechanism B2 is connected with the conveying mechanism A1 through a connecting rod 10, and two ends of the connecting rod 10 are respectively fixed on the connecting frames 4 of the conveying mechanism A1 and the conveying mechanism B2, so that the servo motor rotates and drives 4 belt conveying devices 3 to horizontally move. The middle part of the belt conveying device 3 with the same height is provided with a camera 11. As shown in fig. 4, a two-dimensional code 12 is provided between the two belt conveyors of the receiving mechanism that cooperate with the conveying mechanism. Belt conveyor 3 be provided with the sensor that is used for detecting transmission goods quantity, detect whether the goods satisfies the conveying quantity requirement through infrared sensor. The belt conveying device comprises a driving wheel, a driven wheel and a synchronous belt, wherein the driving wheel and the driven wheel are connected through the synchronous belt, and the driving wheel is connected with the motor. The AGV carrier also has a controller, and the controller is connected with sensor, camera respectively, and simultaneously, the controller is connected with the motor, the operating condition of control motor to control conveying mechanism's lateral shifting and belt conveyors conveying goods.

As shown in fig. 4, a coordinate system is established with the camera 11 as the origin, the coordinate system is a left-handed coordinate system, the centerline of the AGV parallel to the ground and perpendicular to the centerline is taken as the X-axis, and the centerline of the AGV is taken as the Y-axis; and installing the two-dimensional code 12 at the target point, wherein the surface of the two-dimensional code 12 is flush with the end face of the belt conveying device, and establishing a coordinate system by using the center of the two-dimensional code 12 as an origin point by adopting the same method.

Under the condition of not considering errors, the relative positions of the AGV and the receiving mechanism after butt joint are shown in fig. 5, the distance between the end faces of the two conveying belts is D, the distance between the camera 11 and the end face of the conveying belt of the AGV is H, the angle between the center line of the AGV and the center line of the receiving target point is 0 °, and the distance in the X direction is 0 mm.

In practical engineering applications, after the AGV stops at a target point, the relative position is as shown in fig. 6, and three-dimensional data including a Y-axis direction distance L, an X-axis direction distance S, and a Y-axis direction angle θ between the camera 11 and the two-dimensional code 12 is read through the two-dimensional code 12. That is, the camera 11 obtains the distance L between the camera 11 and the two-dimensional code 12 along the conveying direction, the distance S between the camera 11 and the two-dimensional code 12 perpendicular to the conveying direction, and the included angle θ between the facing direction of the camera 11 and the conveying direction. When the AGV transporting vehicle transports the goods to the target point, in order to ensure smooth delivery of the goods, after the horizontal movement of the transporting mechanism is ensured, the intersection point of the AGV central line and the central line of the target point track (namely the central lines of the two belt transporting devices of the receiving mechanism) is moved to the center of the end face of the target point track. Since the center line of the camera 11 is parallel to the center line of the AGV belt conveyor 3, the distance δ from the intersection point a of the center line of the camera 11 and the plane where the two-dimensional code 12 is located to the center B of the two-dimensional code 12, that is, the required horizontal movement amount δ = S + L tan θ. The distance that the transport mechanism needs to move by coordinate conversion is ∈ in fig. 8, where ∈ = δ cos θ = S cos θ + L sin θ, and ∈ is shown in fig. 7 as the amount of lateral displacement of the transfer movement. The main controller controls the servo motor to rotate to drive the conveying mechanism to move horizontally, and after the conveying mechanism moves in place, the two-dimensional code data is read to form closed-loop control, so that the whole transfer mechanism is precisely butted with the target point receiving mechanism; after the conveying mechanism is transversely in place, the controller controls the conveying motor to rotate, and the belt conveying device is driven to convey goods.

Claims

1. An accurate transfer control method suitable for an AGV is characterized in that an image acquisition unit is arranged on the AGV carrier with a conveying mechanism, a two-dimensional code is arranged at a target position, three-dimensional data of the two-dimensional code is read through the image acquisition unit, and deviation between the conveying mechanism and a butt joint conveying point is calculated through the three-dimensional data and is used as the transverse displacement of the conveying mechanism.

2. The method according to claim 1, wherein the three-dimensional data includes a distance L between the image capturing unit and the two-dimensional code along the transport direction, a distance S between the image capturing unit and the two-dimensional code perpendicular to the transport direction, and an angle θ between the facing direction of the image capturing unit and the transport direction.

3. An accurate transfer control method for AGV according to claim 2, wherein the calculation formula of the lateral displacement is: the amount of lateral displacement = S × cos θ + L × sin θ.

4. The method of claim 1, wherein the AGV includes a transport body having a horizontally movable transport mechanism.

5. The method of claim 4, wherein the transport mechanism includes a transport mechanism A (1) and a transport mechanism B (2), each of the transport mechanism A (1) and the transport mechanism B includes two belt conveyors (3) arranged side by side, the two belt conveyors (3) are connected by a connecting frame (4), each of the connecting frames (4) of the transport mechanism A is provided with a rack (5), the rack (5) is engaged with a gear (6) fixed on an output shaft of the servo motor, and the connecting frame (4) of the transport mechanism A (1) is slidably connected with the cart body.

6. The method of claim 5, wherein the transporting vehicle body has a slide rail (7), the connecting frame (4) has a slide block (8), and the slide block (8) has a sliding slot adapted to the slide rail (7).

7. The method of claim 5, wherein the transport mechanism B (2) is connected to the body of the AGV via a fixing frame (9), such that the transport mechanism A (1) and the transport mechanism B (2) are vertically disposed, the connecting frame (4) of the transport mechanism B (2) is slidably connected to the fixing frame (9), and the transport mechanism B (2) is connected to the transport mechanism A (1) via a connecting rod (10).

8. An accurate transfer control method for AGVs according to claim 8, characterized in that both ends of the connecting rod (10) are fixed to the connecting frames (4) of the transport mechanism a (1) and the transport mechanism B (2), respectively.

9. A precise transfer control method for AGV according to claim 5, wherein said belt conveyor (3) is provided with an infrared sensor for detecting the amount of the transported goods.