AGV fork truck with tray visual identification and laser closed-loop distance adjustment

Abstract

The utility model discloses a kind of AGV fork trucks with tray visual identification and laser closed-loop distance adjustment, it is related to AGV fork truck technical field, including the portal for being connected with vehicle body, portal front end slidingly equipped with fork carriage, symmetrically slidingly equipped with fork on fork carriage, it is also symmetrically equipped with hydraulic cylinder two on fork carriage, the movable end of hydraulic cylinder two is equipped with connector two, and connector two is respectively fixedly connected with corresponding fork, and drive assembly is equipped on portal;Depth camera is installed on the fork carriage between fork;Symmetrically install laser range finder on fork carriage;The utility model is cooperated with the use of depth camera and laser range finder, and it is convenient for fork to accurately aim at tray, also avoid the collision of fork and tray, thereby facilitate the use of AGV fork truck.

Description

Technical Field

[0001] This utility model relates to the field of AGV forklift technology, and in particular to an AGV forklift with pallet vision recognition and laser closed-loop distance adjustment. Background Technology

[0002] With the development of intelligent manufacturing and warehouse automation, automated guided vehicles (AGVs) are increasingly widely used in material handling. However, traditional AGVs generally face the following technical bottlenecks in pallet docking:

[0003] 1. Low pallet recognition accuracy: Most traditional AGV forklifts rely on fixed paths or coarse mechanical positioning, lacking the ability to perceive the pallet's posture (position and angle) in real time. Especially in scenarios with pallet placement deviations, uneven ground, or multiple pallets stacked, there is a risk of forklift failure or collision.

[0004] 2. Lack of closed-loop adjustment mechanism: Existing systems typically use open-loop control to complete the insertion action after the fork arm approaches the pallet. This makes it impossible to dynamically adjust the vehicle body or fork arm posture according to the actual position of the pallet, resulting in insertion deviation, pallet deformation, or even cargo tipping.

[0005] 3. Inability to adapt to pallets with different hole spacing: The fork arm spacing of traditional AGV forklifts is mostly fixed or only supports limited gear adjustment. They lack the ability to sense and adapt to pallet fork hole spacing online. When faced with pallets of different specifications and hole spacing, it is necessary to manually change tooling or pre-set parameters. It is impossible to achieve truly flexible forklifting, which seriously restricts the efficiency and versatility of multi-category mixed line operations.

[0006] The aforementioned problems severely restrict the reliability and operational efficiency of AGV forklifts in flexible manufacturing and high-density warehousing scenarios. There is an urgent need for a new type of AGV forklift technology that integrates high-precision pallet vision recognition and real-time laser closed-loop distance adjustment to achieve intelligent, precise, and unmanned pallet picking process. Summary of the Invention

[0007] This invention addresses the problems in the background technology by proposing an AGV forklift with pallet vision recognition and laser closed-loop distance adjustment.

[0008] To achieve the above objectives, the present invention adopts the following technical solution:

[0009] An AGV forklift with pallet vision recognition and laser closed-loop distance adjustment includes a mast for connecting to the vehicle body. A fork carriage is slidably provided at the front end of the mast. A second hydraulic cylinder is symmetrically provided on the fork carriage. Sliding forks are also symmetrically provided on the fork carriage and driven by the second hydraulic cylinder. The fixed end of the second hydraulic cylinder is hinged to the fork carriage, and the movable end is provided with a second connector. The second connector is fixedly connected to the corresponding fork. The mast is provided with a drive assembly for lifting and lowering the fork carriage.

[0010] A depth camera is installed on the fork carriage between the forks;

[0011] Laser rangefinders are symmetrically mounted on the forklift carriage.

[0012] Preferably, the drive assembly includes a hydraulic cylinder mounted on the mast, a connector fixed to the movable end of the hydraulic cylinder, and pulleys symmetrically rotatably mounted on the connector. A support frame is fixed to the mast, and a plate chain is symmetrically fixed to the support frame. One end of the plate chain passes through the pulley and is fixed to the fork carriage.

[0013] Preferably, the fork carriage is provided with symmetrical grooves, and a slider is slidably disposed in the grooves and the slider is fixedly connected to the fork.

[0014] Preferably, a connecting rod is fixedly connected to the fork, a chain is provided on the connecting rod, and the chain is fixedly connected to the top of the fork carriage. A laser target plate that cooperates with a laser rangefinder is provided on the outer side of the connecting rod.

[0015] Preferably, a positioning detection element is provided on the outer side of the fork. The positioning detection element includes a baffle that is rotatably mounted on the outer side of the fork via a torsion spring shaft, and a pressure sensor is provided on the rear end face of the baffle.

[0016] Preferably, the mast is provided with symmetrical sliding grooves, the fork carriage is provided with symmetrical connecting blocks, and the connecting blocks are provided with sliding blocks that cooperate with the sliding grooves.

[0017] In summary, due to the adoption of the above technical solution, the beneficial effects of this utility model are:

[0018] This invention utilizes a depth camera and a laser rangefinder in combination to facilitate precise alignment of the forks with the pallet, while also preventing collisions between the forks and the pallet, thus improving the usability of the AGV forklift. Furthermore, it allows for precise adjustment of the AGV forklift's forks, making it suitable for pallets with different hole spacings. Attached Figure Description

[0019] Figure 1 A structural schematic diagram from an orthographic perspective is shown according to an embodiment of the present invention;

[0020] Figure 2 A rear-view structural schematic diagram is shown according to an embodiment of the present invention;

[0021] Figure 3 A top-view structural schematic diagram is shown according to an embodiment of the present invention;

[0022] Figure 4 for Figure 3 A magnified view of a section at point A in the middle;

[0023] Figure 5 A schematic diagram of the fork carriage provided according to an embodiment of the present invention is shown.

[0024] Legend:

[0025] 1. Mast; 2. Fork carriage; 3. Slider 1; 4. Depth camera; 5. Forks; 6. Position detection component; 7. Laser rangefinder; 8. Connecting rod; 9. Chain 1; 10. Slide 1; 11. Chain 2; 12. Support frame; 13. Connector 1; 14. Hydraulic cylinder 1; 15. Pulley; 16. Slide 2; 17. Connecting block; 18. Slider 2; 19. Connector 2; 20. Hydraulic cylinder 2. Detailed Implementation

[0026] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of the present utility model.

[0027] Please see Figures 1-5 This utility model provides a technical solution:

[0028] An AGV forklift with pallet vision recognition and laser closed-loop distance adjustment includes a mast 1 for connecting to the vehicle body. A fork carriage 2 is slidably mounted on the front end of the mast 1, and forks 5 are symmetrically slidably mounted on the fork carriage 2. Hydraulic cylinders 20 are also symmetrically mounted on the fork carriage 2, and the fixed end of the hydraulic cylinders 20 is fixed to the edge of the fork carriage 2 by bolts. The movable end of the hydraulic cylinders 20 is provided with a connector 19, and the connector 19 is fixed to the corresponding fork 5. The mast 1 is provided with a drive assembly for lifting and lowering the fork carriage 2. The use of the drive assembly facilitates the lifting and lowering of the fork carriage 2, thereby facilitating the lifting and lowering of goods.

[0029] A depth camera 4 is installed on the fork carriage 2 between the forks 5, and the depth camera 4 is installed in the middle of the forks 5, covering an area with a lateral field of view of 70° and a longitudinal field of view of 90°; the depth camera 4 provides the pixel angle Δθ between the center lines of the left and right insertion holes of the pallet at one time; the AGV uses this angle as the target and achieves stationary or circular rotation through the steering wheel chassis to make the front direction parallel to the long side of the pallet (|Δθ|≤1°); after the vehicle body is aligned, the depth camera 4 and the laser rangefinder 7 are combined to calculate the target movement amount ΔL and ΔR of the left and right forks according to the original dual closed-loop algorithm; the dual-side hydraulic servo cylinders complete the spacing adjustment with an accuracy of ≤1mm under 1kHz laser feedback; insertion of safety ring: after the posture adjustment and fork adjustment are completed, the AGV moves forward at a pure longitudinal speed to insert; if the vehicle body angle fluctuation is detected to be >0.3° or the fork displacement fluctuation is detected to be >2mm, the vehicle body angle fluctuation is detected to be >0.3° or the fork displacement fluctuation is detected to be >2mm, the vehicle body angle fluctuation is detected to be >0.3° or >2mm, and ...

[0030] Laser rangefinders 7 are symmetrically installed on the fork carriage 2; the cooperation between the depth camera 4 and the laser rangefinders 7 makes it easy for the forks 5 to accurately align with the pallet, and also avoids collisions between the forks 5 and the pallet, thus facilitating the use of the AGV forklift.

[0031] In this utility model, the drive assembly includes a hydraulic cylinder 14 mounted on the mast 1, a connector 13 fixed to the movable end of the hydraulic cylinder 14, and a pulley 15 symmetrically rotatably mounted on the connector 13. A support frame 12 is fixedly mounted on the mast 1, and a chain 11 is symmetrically fixedly mounted on the support frame 12. One end of the chain 11 passes through the pulley 15 and is fixedly connected to the fork carriage 2. The use of the pulley 15 facilitates changing the direction of the chain 11, while reducing the friction of the chain 11 and improving its service life.

[0032] In this utility model, the fork carriage 2 is symmetrically provided with a sliding groove 10, and a slider 3 is slidably provided in the sliding groove 10. The slider 3 is fixedly connected to the fork 5. The use of the slider 3 makes it easy for the fork 5 to slide on the fork carriage 2.

[0033] In this utility model, a connecting rod 8 is fixedly connected to the fork 5, and a chain 9 is provided on the connecting rod 8. The chain 9 is fixedly connected to the top of the fork carriage 2. The use of the chain 9 improves the stability of the movement of the fork 5. A laser target plate that cooperates with the laser rangefinder 7 is provided on the outer side of the connecting rod 8 for measuring the distance from the fork 5 to both sides, thereby facilitating the insertion of the fork 5 into the pallet.

[0034] In this invention, a positioning detection component is provided on the outer side of the fork 5. The positioning detection component includes a baffle that is rotatably mounted on the outer side of the fork 5 via a torsion spring shaft for automatic resetting of the baffle. A pressure sensor is provided on the rear end face of the baffle, and the pressure sensor is connected to the control system of the AGV forklift. When the fork 5 is in position, the baffle will rotate, thereby pressing the pressure sensor. At this time, the pressure sensor receives the signal and transmits the signal to the control system of the AGV forklift. After processing by the control system of the AGV forklift, the AGV forklift will issue an alarm to remind the operator that the fork 5 has been positioned.

[0035] In this utility model, the mast 1 is provided with symmetrical sliding grooves 16, and the fork carriage 2 is provided with symmetrical connecting blocks 17. The connecting blocks 17 are provided with sliders 18 that cooperate with the sliding grooves 16. The use of sliders 18 facilitates the stable lifting and lowering of the fork carriage 2.

[0036] Working principle: When using this invention, the distance between the forks 5 is first adjusted according to the pallet. Specifically, the two hydraulic cylinders 20 are opened first. The movable end of the hydraulic cylinder 20 extends and drives the connector 19 to move, thereby driving the relative movement of the forks 5 and realizing the adjustment of the forks 5.

[0037] Before adjusting the forks 5, the depth camera 4 acquires images of the pallet, analyzes the acquired images, identifies the positions of the left and right fork holes of the pallet and the angle Δθ between the line connecting their centers and the direction of the vehicle body; the AGV forklift rotates in place or in an arc according to this angle Δθ through the steering wheel chassis, so that the direction of the vehicle head is parallel to the long side of the pallet (|Δθ|≤1°), realizing automatic correction of the vehicle body direction; after the vehicle body is aligned, the depth camera 4 and the laser rangefinder 7 work together, using a dual closed-loop control algorithm to calculate the target movement amounts ΔL and ΔR of the left and right forks 5, and the dual hydraulic cylinders 20 complete the spacing adjustment with an accuracy of ≤1mm under 1kHz laser feedback, ensuring that the forks 5 are accurately aligned with the pallet fork holes;

[0038] When fork 5 is inserted into the pallet, after eliminating the risk of collision, fork 5 continues to be driven into the pallet fork hole until the vertical end of fork 5 (i.e. the side of the fork perpendicular to the horizontal insertion direction) gradually approaches the inner wall of the pallet. At this time, the laser rangefinder 7 installed at the vertical end of fork 5 will start working, emitting laser signals to the inner wall of the pallet in real time and receiving reflected signals to calculate the real-time distance between the vertical end of the fork and the inner wall of the pallet. The laser rangefinder 7 continuously transmits the calculated distance signal to the depth camera 4. The depth camera 4 analyzes the distance signal in real time. When it detects that the distance between the two has decreased to the preset "safe stop threshold" (this threshold is set in advance according to the size parameters of the pallet and fork to ensure that the fork insertion depth is sufficient to stably support the pallet, while avoiding over-insertion that may cause pallet deformation), it immediately sends a "pause" command to the power system, causing the AGV forklift to stop moving and fork 5 to stop inserting. At this point, the operation of inserting the fork into the pallet is safely completed.

[0039] Then, open hydraulic cylinder 14, and drive connector 13 to rise and fall through the lifting and lowering of the movable end of hydraulic cylinder 14. Then, under the action of chain 2 11, the fork carriage 2 is lifted and lowered, thereby driving the forks 5 to rise and fall, and further driving the pallet to rise and fall.

[0040] The above description of the embodiments enables those skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. An AGV forklift with pallet vision recognition and laser closed-loop distance adjustment, comprising a mast (1) for connection with the vehicle body, characterized in that, The mast (1) is slidably provided with a fork carriage (2) at the front end, and forks (5) are symmetrically slidably provided on the fork carriage (2). Hydraulic cylinders (20) are also symmetrically provided on the fork carriage (2). Connector (19) is provided at the movable end of the hydraulic cylinder (20), and connector (19) is fixedly connected to the corresponding forks (5). The mast (1) is provided with a drive assembly for lifting the fork carriage (2). A depth camera (4) is installed on the fork carriage (2) between the forks (5); Laser rangefinders (7) are symmetrically mounted on the forklift (2).

2. The AGV forklift with pallet vision recognition and laser closed-loop distance adjustment according to claim 1, characterized in that, The drive assembly includes a hydraulic cylinder (14) mounted on the mast (1), a connector (13) fixed to the movable end of the hydraulic cylinder (14), and a pulley (15) symmetrically rotated on the connector (13). A support frame (12) is fixedly mounted on the mast (1), and a chain (11) is symmetrically fixedly mounted on the support frame (12). One end of the chain (11) passes through the pulley (15) and is fixedly mounted to the fork carriage (2).

3. The AGV forklift with pallet vision recognition and laser closed-loop distance adjustment according to claim 1, characterized in that, The fork carriage (2) is symmetrically provided with a sliding groove (10), and a slider (3) is slidably provided in the sliding groove (10), and the slider (3) is fixedly connected to the fork (5).

4. The AGV forklift with pallet vision recognition and laser closed-loop distance adjustment according to claim 1, characterized in that, A connecting rod (8) is fixedly connected to the fork (5), and a chain (9) is provided on the connecting rod (8). The chain (9) is fixedly connected to the top of the fork frame (2). A laser target plate that cooperates with the laser rangefinder (7) is provided on the outer side of the connecting rod (8).

5. The AGV forklift with pallet vision recognition and laser closed-loop distance adjustment according to claim 1, characterized in that, The fork (5) is provided with a positioning detection device on its outer side. The positioning detection device includes a baffle that is rotatably mounted on the outer side of the fork (5) via a torsion spring shaft. A pressure sensor is provided on the rear end face of the baffle.

6. The AGV forklift with pallet vision recognition and laser closed-loop distance adjustment according to claim 1, characterized in that, The mast (1) is symmetrically provided with two sliding grooves (16), and the fork frame (2) is symmetrically provided with connecting blocks (17). The connecting blocks (17) are provided with two sliding blocks (18) that cooperate with the two sliding grooves (16).

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