Forward moving type AGV double-pallet-fork operation control system and control method

Abstract

The invention discloses a forward moving type AGV double-pallet-fork operation control system and method, and relates to the technical field of storage equipment, and the system comprises a lithium battery which provides a voltage-stabilized power supply for an AGV; the VCU controller is used for controlling the AGV to operate all actions; the lifting controller is connected with the VCU controller through CAN communication and executes the operation instruction issued by the VCU controller; a lifting motor; a travel motor; a travel controller; a solenoid valve module; a lifting encoder; a detection module; and a brake relay module. According to the method, by optimizing the AGV control strategy, compared with a traditional single-fork goods taking and placing efficiency, the efficiency is greatly improved, meanwhile, the requirement for the AGV performance is lowered, the safety risk caused by the fact that the single fork improves the operation speed for improving the working efficiency is lowered, and in addition, compared with a method for improving the working efficiency through multiple AGVs, the method has the advantage that the working efficiency is greatly improved. The use cost is obviously reduced, and cost control is facilitated.

Description

Technical Field

[0001] This invention relates to the field of warehousing equipment technology, specifically a forward-moving AGV dual-fork operation control system and control method. Background Technology

[0002] When AGVs are performing normal picking and placing tasks, they usually use single fork operations. For some project sites with relatively simple working conditions and large workloads, such as soft packaging stacking, "soft packaging stacking" usually refers to the stacking and placement of soft-packaged goods (such as bags, woven bags, pillow packaging, etc.) in the process of logistics, warehousing and transportation.

[0003] For project sites with relatively simple working conditions and a large workload, there are usually two ways to improve work efficiency: First, increase the running speed of AGVs to indirectly improve work efficiency, but this requires very high AGV performance and also increases safety risks; Second, use multiple AGVs to improve work efficiency. While this improves overall work efficiency, it also inevitably increases the cost of use significantly, making cost control difficult.

[0004] Therefore, how to improve the working efficiency of AGVs while minimizing the increase in investment costs has become the focus of AGV research. This application provides a control strategy for improving the working efficiency of forward-moving AGVs in soft-pack stacking scenarios. Summary of the Invention

[0005] The purpose of this invention is to provide a forward-moving AGV dual-fork operation control system and control method to solve the problems mentioned in the background art.

[0006] To achieve the above objectives, the present invention provides the following technical solution: a forward-moving AGV dual forklift operation control system, comprising: a lithium battery, providing a regulated power supply to the AGV; The key switch controls whether the AGV is powered on or off. The VCU controller controls all actions of the AGV and receives signals from various sensors. The hoisting controller is connected to the VCU controller via CAN communication and executes the operation commands issued by the VCU controller. The lifting motor enables the lifting, lowering, forward and backward movement of the forks, and is connected to the lifting controller via a three-phase cable. The drive motor enables the AGV to move forward and backward. The driving controller is connected to the driving motor via a three-phase cable and to the VCU controller via CAN communication; The solenoid valve module controls the flow of hydraulic oil, and controls the lifting, lowering, forward movement, and backward movement of the forks through the pressure of the hydraulic oil. Lift encoders are used to accurately provide feedback on the lifting height of the forks, and there are upper fork lift encoders and lower fork lift encoders; The detection module is used to detect obstacles in front of the forks, load status, and cargo detachment. The braking relay module enables the AGV to stop in a timely manner.

[0007] Preferably, the solenoid valve module includes: an upper fork lifting solenoid valve, an upper fork lowering solenoid valve, a lower fork lifting solenoid valve, a lower fork lowering solenoid valve, a fork forward moving solenoid valve, and a fork backward moving solenoid valve; When the lower fork lifting solenoid valve or the lower fork lowering solenoid valve is opened, the upper fork and the lower fork move synchronously; when the upper fork lifting solenoid valve or the upper fork lowering solenoid valve is activated, the upper fork moves independently.

[0008] Preferably, the detection module includes: The fork tip detection sensor is a photoelectric sensor installed at the tip of the upper fork to detect obstacles in front of the fork; The load sensor, which is an ultrasonic sensor, is installed at the root of the fork and is used to detect the completion of picking up goods. It includes the upper fork load sensor and the lower fork load sensor. The load pressure sensor is a ring-shaped force sensor installed on the top cylinder of the mast. It outputs an analog signal with a value of 0-2000, and can detect 0-2 tons of cargo. It is used to determine whether the cargo has detached from the forks. It includes load pressure sensors for the upper and lower forks.

[0009] Preferably, the braking relay module is a 5-contact intermediate relay, comprising: The brake relay coil is controlled by the output port of the VCU controller; The electromagnetic brake is an electromagnetic friction brake that locks when power is lost. It is installed on the rotating shaft of the travel motor and stops the AGV by locking the rotation of the travel motor. It is controlled by the output port of the VCU controller. The normally closed contact of the brake relay is connected in the electromagnetic brake circuit.

[0010] Preferably, the lifting controller and the travel controller are both AC controllers, and the lifting motor and the travel motor are both AC motors; the lifting encoder is a CAN absolute encoder.

[0011] A method for controlling the operation of a forward-moving AGV with dual forks includes the following steps: S1: First, the VCU controller controls the AGV to run to the picking station via CAN communication; S2: The VCU controller controls the lower fork lifting solenoid valve to open via CAN communication, and both forks are lifted together. After the lower fork is lifted to the set height and passes the test, both forks stop running together. S3: The VCU controller controls the opening of the upper fork lifting solenoid valve via CAN communication, allowing the upper fork to lift independently to the set height. After the height is detected as qualified, the upper fork stops operating. S4: After the dual forks are raised to the position, the VCU controller controls the fork forward movement solenoid valve to be energized and opened via CAN communication, and the dual forks move forward simultaneously; at this time, the status of the upper fork load sensor and the lower fork load sensor is detected. When both are triggered, the dual forks stop moving forward. S5: The VCU controller controls the lower fork lifting solenoid valve to open, and both forks lift together. The lifting continues until the upper fork load pressure sensor and the lower fork load pressure sensor provide qualified data to the VCU controller input port, at which point both forks stop running. S6: The VCU controller controls the fork retraction solenoid valve to be energized and opened via CAN communication, the lifting motor runs, and both forks move backward simultaneously. After reaching the position, the fork retraction solenoid valve is de-energized and closed, and the picking is completed. S7: The VCU controller controls the electromagnetic brake to be energized and released, the travel motor to run, and after the AGV runs to the designated delivery station, the VCU controller controls the travel motor to stop running, the electromagnetic brake to be de-energized and locked, and the AGV to stop running; the VCU controller controls the fork forward solenoid valve to be energized and opened through CAN communication, and both forks move forward at the same time. After moving forward to the position, the fork forward solenoid valve is de-energized and closed. S8: The VCU controller energizes and opens the lower fork descent solenoid valve, causing both forks to descend simultaneously to the specified height. It then detects the values ​​of the lower fork lifting encoder and the lower fork load pressure sensor. Once the values ​​are within acceptable limits, the VCU controller de-energizes and closes the lower fork descent solenoid valve, stopping the operation of both forks. The VCU controller energizes and opens the solenoid valve for lowering the upper fork, causing the upper fork to descend. It detects the data from the upper fork load pressure sensor. When the data from the upper fork load pressure sensor is within acceptable limits and is fed back to the VCU controller's input port 7, it indicates that the upper fork has descended to the designated position. The VCU controller then stops the upper fork from descending. S9: The VCU controller controls the fork retraction solenoid valve to open via CAN communication, and both forks move backward simultaneously. Once in position, the VCU controller de-energizes the fork retraction solenoid valve to close, the lifting motor stops running, and the unloading is completed.

[0012] Preferably, in step S2, the pass / fail standard is: the lower fork is continuously raised to a set height of 2000mm, and the data of the lower fork lifting encoder is detected. The difference between the lower fork being raised to the set height and the height value fed back by the lower fork lifting encoder is less than or equal to 5mm.

[0013] Preferably, in step S3, the pass standard is: the upper fork is continuously raised to a set height of 3000mm, and the upper fork lifting encoder data is detected. The difference between the upper fork being raised to the set height and the height value fed back by the upper fork lifting encoder is less than or equal to 5mm.

[0014] Preferably: In step S5, the data of the upper fork load pressure sensor and the lower fork load pressure sensor are detected, and the lifting continues until the data fed back to the VCU controller input port by the upper fork load pressure sensor and the lower fork load pressure sensor is greater than 1000, at which point both forks stop running together.

[0015] Preferably: In step S8, when the lower fork descends to a specified height of 50mm, the values ​​of the lower fork lifting encoder and the lower fork load pressure sensor are detected. When the difference between the lower fork descending to the set height and the height value fed back by the lower fork lifting encoder is less than or equal to 5mm, and the data fed back by the lower fork load pressure sensor to the VCU controller input port is less than or equal to 100, the VCU controller controls the lower fork descent solenoid valve to de-energize and shut off, and the double forks stop operating. At this time, the data of the upper fork load pressure sensor is detected. When the data fed back by the upper fork load pressure sensor to the VCU controller input port is less than or equal to 100, it indicates that the upper fork has descended to the specified position.

[0016] Compared with the prior art, the beneficial effects of the present invention are: This application addresses the use of reach AGVs in soft-pack stacking scenarios. By installing lifting encoders on both forks, the lifting height of the upper and lower forks is precisely controlled. Fork tip sensors, cargo pressure sensors, and load sensors are used to provide feedback on various operating states during the AGV's loading and unloading process. The operating states of the lifting motor and travel motor are then monitored to achieve the loading and unloading tasks in soft-pack stacking scenarios. By optimizing the AGV control strategy, the loading and unloading efficiency is greatly improved compared to traditional single-fork loading and unloading methods. At the same time, the performance requirements of the AGV are reduced, and the safety risks associated with increasing the operating speed of a single fork to improve work efficiency are also reduced. In addition, compared to using multiple AGVs to improve work efficiency, this application significantly reduces the cost of use, which is beneficial for cost control. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the control system principle of the present invention; Figure 2 This is a schematic diagram of one control flow of the present invention; Figure 3 This is a schematic diagram of another control flow of the present invention.

[0018] In the diagram: 1. Lithium battery; 2. Key switch; 3. Lifting controller; 4. Lifting motor; 5. Travel controller; 6. Travel motor; 7. VCU controller; 8. Upper fork lifting solenoid valve; 9. Upper fork lowering solenoid valve; 10. Lower fork lifting solenoid valve; 11. Lower fork lowering solenoid valve; 12. Fork forward solenoid valve; 13. Fork backward solenoid valve; 14. Upper fork lifting encoder; 15. Lower fork lifting encoder; 16. Fork tip detection sensor; 17. Upper fork load sensor; 18. Lower fork load sensor; 19. Upper fork load pressure sensor; 20. Lower fork load pressure sensor; 21. Brake relay coil; 22. Brake relay normally closed contact; 23. Electromagnetic brake. Detailed Implementation

[0019] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0020] In the description of the embodiments of the present invention, it should be noted that the terms "inner", "outer", "upper", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship in which the product of the invention is usually placed when in use. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting the present invention.

[0021] Please see Figure 1-3 In this embodiment of the invention, a forward-moving AGV dual-forklift operation control system includes: The lithium battery 1 provides a 48V regulated power supply to the AGV, and the key switch 2 controls the AGV to turn on or off.

[0022] The hoisting controller 3 is an AC controller that controls the operation of the hoisting motor 4. It is connected to the VCU controller 7 via CAN communication and executes the operation commands issued by the VCU controller 7.

[0023] The lifting motor 4 is an AC motor that realizes the lifting, lowering, forward and backward movement of the forks. It is connected to the lifting controller 3 through a three-phase cable. The lifting controller 3 controls the current of the three-phase cable to change the speed of the lifting motor 4.

[0024] The driving controller 5 is an AC controller that controls the operation of the driving motor 6. It is connected to the VCU controller 7 via CAN communication and executes the operation commands issued by the VCU controller 7.

[0025] The travel motor 6 is an AC motor that enables the AGV to move forward and backward. It is connected to the travel controller 5 via a three-phase cable. The travel controller 5 controls the current in the three-phase cable to change the speed of the travel motor 6.

[0026] The VCU controller 7 controls all actions of the AGV, receives signals from various sensors, processes them, and sends various instructions to the corresponding devices to execute corresponding actions.

[0027] Solenoid valves control the flow of hydraulic oil, and control the lifting, lowering, forward movement, and backward movement of the forks through the pressure of the hydraulic oil. (It should be noted that controlling the lifting, lowering, forward movement, and backward movement of the forks through the pressure of hydraulic oil is a common technique. It is common to use a lifting motor 4 to drive the hydraulic pump of the hydraulic system, pump out high-pressure hydraulic oil, and control the flow direction of the high-pressure oil through solenoid valves, determining whether the oil flows to the lifting cylinder (for lifting) or flows back from the lifting cylinder to the oil tank (for lowering)). The solenoid valves are: upper fork lifting solenoid valve 8, upper fork lowering solenoid valve 9, lower fork lifting solenoid valve 10, lower fork lowering solenoid valve 11, fork forward movement solenoid valve 12, and fork backward movement solenoid valve 13.

[0028] The lifting encoders are CAN absolute encoders used to accurately feed back the lifting height of the forks. They are the upper fork lifting encoder 14 and the lower fork lifting encoder 15.

[0029] The fork tip detection sensor 16 is a photoelectric sensor installed at the tip of the upper fork to detect obstacles in front of the fork.

[0030] The load sensors are ultrasonic sensors installed at the root of the forks to detect whether the picking is completed. They are the upper fork load sensor 17 and the lower fork load sensor 18.

[0031] The load pressure sensor is a ring-shaped force sensor installed on the top cylinder of the mast. It outputs an analog signal with a value of 0-2000, and can detect 0-2 tons of cargo. It is used to determine whether the cargo has detached from the forks. A normal value of less than 100 indicates that there is no cargo. The load pressure sensors are 19 for the upper forks and 20 for the lower forks.

[0032] The brake relay is a 5-contact intermediate relay. The brake relay coil 21 is controlled by the output port of the VCU controller 7. The normally closed contact 22 of the brake relay is connected in the electromagnetic brake 23 circuit to realize the timely stopping of the AGV.

[0033] The electromagnetic brake 23 is an electromagnetic friction brake that locks when power is lost. It is installed on the rotating shaft of the travel motor 6 and stops the AGV by locking the rotation of the travel motor 6. The signal is controlled through the output port of the VCU controller 7.

[0034] Figure 2 This is a flowchart of one type of forward-moving AGV double forklift operation control method, which is used for picking and placing 1 ton of goods. The scenario is: two rows of goods are taken out of the rack and stacked on the ground.

[0035] The specific implementation steps are as follows: S1: The VCU controller 7 sends a speed of 2000 RPM to the driving controller 5 via CAN communication and controls the output port OUT7 to a low level. This de-energizes the brake relay coil 21, closes the normally closed contact 22 of the brake relay, energizes and releases the electromagnetic brake 23, and starts the driving motor 6, allowing the AGV to run automatically. After the AGV reaches the designated station to pick up goods, the VCU controller 7 sends a speed of 0 RPM to the driving controller 5 via CAN communication. The driving motor 6 stops running, and simultaneously, the VCU controller 7 controls the output port OUT7 to a high level. This energizes the brake relay coil 21, opens the normally closed contact 22 of the brake relay, de-energizes and locks the electromagnetic brake 23, and stops the AGV from running.

[0036] S2: The VCU controller 7 sends a speed of 2000 RPM to the lifting controller 3 via CAN communication and controls the output port OUT3 to a high level. The lower fork lifting solenoid valve 10 is energized and opens, the lifting motor 4 starts running, and both forks lift together. The lower forks continue to lift to the set height of 2000 mm, and the data of the lower fork lifting encoder 15 is detected. When the difference between the lower fork lifting to the set height and the height value fed back by the lower fork lifting encoder 15 is less than or equal to 5 mm, the VCU controller 7 sends a speed of 0 RPM to the lifting controller 3 via CAN communication and controls the output port OUT3 to a low level. The lower fork lifting solenoid valve 10 is de-energized and closes, the lifting motor 4 stops running, and both forks stop running together.

[0037] S3: At this time, VCU controller 7 sends a speed of 1000 to lifting controller 3 via CAN communication and controls output port OUT2 to a high level. The upper fork lifting solenoid valve 8 is energized and opens, lifting motor 4 starts running, and the upper fork lifts independently. The upper fork continues to lift to the set height of 3000mm, and the data of upper fork lifting encoder 14 is detected. When the difference between the upper fork lifting to the set height and the height value fed back by upper fork lifting encoder 14 is less than or equal to 5mm, VCU controller 7 sends a speed of 0 to lifting controller 3 via CAN communication and controls output port OUT2 to a low level. The upper fork lifting solenoid valve 8 is de-energized and closes, lifting motor 4 stops running, and the upper fork stops operating.

[0038] S4: When both forks are raised to the correct position, the VCU controller 7 sends a 1000 RPM speed command to the lifting controller 3 via CAN communication and controls the output port OUT5 to be high. The fork forward solenoid valve 12 is energized and opens, the lifting motor 4 starts running, and both forks move forward simultaneously. At this time, the status of the upper fork load sensor 17 and the lower fork load sensor 18 is detected. When both forks have moved forward to the point where both the upper fork load sensor 17 and the lower fork load sensor 18 are triggered, the forks are in position. The input ports IN2 and IN3 of the VCU controller 7 are high, the output port OUT5 of the VCU controller 7 is low, the fork forward solenoid valve 12 is de-energized and closes, and sends a 0 RPM speed command to the lifting controller 3 via CAN communication, stopping the forks from moving forward.

[0039] S5: VCU controller 7 sends a speed of 500 to lifting controller 3 via CAN communication and controls output port OUT3 to a high level. The lower fork lifting solenoid valve 10 is energized and opens, lifting motor 4 starts running, and both forks lift together. At this time, the data of upper fork load pressure sensor 19 and lower fork load pressure sensor 20 are detected. Lifting continues until the data fed back from upper fork load pressure sensor 19 and lower fork load pressure sensor 20 to VCU controller 7 input ports IN4 and IN5 are greater than 1000. VCU controller 7 sends a speed of 0 to lifting controller 3 via CAN communication and controls output port OUT3 to a low level. The lower fork lifting solenoid valve 10 is de-energized and closes, lifting motor 4 stops running, and both forks stop running together.

[0040] S6: At this time, VCU controller 7 sends a speed of 1000 to lifting controller 3 via CAN communication and controls the output port OUT6 to be high level. The fork retraction solenoid valve 13 is energized and opens, the lifting motor 4 starts running, and both forks move backward at the same time. After reaching the position, VCU controller 7 sends a speed of 0 to lifting controller 3 via CAN communication and controls the output port OUT6 to be low level. The fork retraction solenoid valve 13 is de-energized and closes, the lifting motor 4 stops running, and the picking is completed.

[0041] S7: The VCU controller 7 sends a speed of 2000 RPM to the driving controller 5 via CAN communication and controls the output port OUT7 to a low level. This de-energizes the brake relay coil 21, closes the normally closed contact 22 of the brake relay, energizes and releases the electromagnetic brake 23, causing the driving motor 6 to start and the AGV to run automatically. After the AGV reaches the designated loading / unloading station, the VCU controller 7 sends a speed of 0 RPM to the driving controller 5 via CAN communication. The driving motor 6 stops running, and simultaneously, the VCU controller 7 controls the output port OUT7 to a high level. This energizes the brake relay coil 21, opens the normally closed contact 22 of the brake relay, de-energizes and locks the electromagnetic brake 23, and the AGV stops running.

[0042] VCU controller 7 sends a speed of 1000 to lifting controller 3 via CAN communication and controls output port OUT5 to be at a high level. The fork forward solenoid valve 12 is energized and opens, lifting motor 4 starts running, and both forks move forward simultaneously. After moving forward to the position, VCU controller 7 sends a speed of 0 to lifting controller 3 via CAN communication and controls output port OUT5 to be at a low level. The fork forward solenoid valve 12 is de-energized and closes, and lifting motor 4 stops running.

[0043] S8: When the VCU controller 7 output port OUT4 is at a high level, the lower fork descent solenoid valve 11 is energized and opened, and both forks descend simultaneously. The lower fork descends to a specified height of 50mm. The values ​​of the lower fork lifting encoder 15 and the lower fork load pressure sensor 20 are detected. When the difference between the lower fork descending to the set height and the height value fed back by the lower fork lifting encoder 15 is less than or equal to 5mm, and the data fed back by the lower fork load pressure sensor 20 to the VCU controller 7 input port IN5 is less than or equal to 100, the VCU controller 7 output port OUT4 is at a low level, the lower fork descent solenoid valve 11 is de-energized and closed, and both forks stop operating.

[0044] When the VCU controller 7 controls the output port OUT2 to be high, the upper fork descent solenoid valve 9 is energized and opens, and the upper fork descends. Since the goods are stacked in soft packaging, the descent height of the upper fork is uncertain. At this time, the data of the upper fork load pressure sensor 19 is detected. When the data fed back by the upper fork load pressure sensor 19 to the VCU controller 7 input port IN4 is less than or equal to 100, the upper fork descends to the designated position, the VCU controller 7 controls the output port OUT2 to be low, the upper fork descent solenoid valve 9 is de-energized and closes, and the upper fork stops descending.

[0045] S9: At this time, VCU controller 7 sends a speed of 1000 to lifting controller 3 via CAN communication and controls the output port OUT6 to be high level. The fork retraction solenoid valve 13 is energized and opens, the lifting motor 4 starts running, and both forks move backward at the same time. After reaching the position, VCU controller 7 sends a speed of 0 to lifting controller 3 via CAN communication and controls the output port OUT6 to be low level. The fork retraction solenoid valve 13 is de-energized and closes, the lifting motor 4 stops running, and the unloading is completed.

[0046] Figure 3 This is a flowchart of another forward-moving AGV double forklift operation control method, which is used for picking and placing 1 ton of goods. The scenario is: the goods are stacked on the ground and taken out and placed on two rows of shelves.

[0047] The specific implementation steps are as follows: Pick-up: VCU controller 7 sends a 2000 RPM speed command to the driving controller 5 via CAN communication and controls the output port OUT7 to a low level. This de-energizes the brake relay coil 21, closes the normally closed contact 22 of the brake relay, energizes and releases the electromagnetic brake 23, and starts the driving motor 6, allowing the AGV to run automatically. After the AGV reaches the designated pickup station, VCU controller 7 sends a 0 RPM speed command to the driving controller 5 via CAN communication. The driving motor 6 stops running, and simultaneously, VCU controller 7 controls the output port OUT7 to a high level. This energizes the brake relay coil 21, opens the normally closed contact 22 of the brake relay, de-energizes and locks the electromagnetic brake 23, and stops the AGV. VCU controller 7 sends a 2000 RPM speed command to lifting controller 3 via CAN communication and controls output port OUT3 to a high level. The lower fork lifting solenoid valve 10 is energized and opens, lifting motor 4 starts running, and both forks lift together. The lower forks continue to rise to the set height of 100mm, and the data from the lower fork lifting encoder 15 is monitored. When the difference between the set height and the height value fed back by the lower fork lifting encoder 15 is less than or equal to 5mm, VCU controller 7 sends a 0 RPM speed command to lifting controller 3 via CAN communication and controls output port OUT3 to a low level. The lower fork lifting solenoid valve 10 is de-energized and closes, lifting motor 4 stops running, and both forks stop operating simultaneously.

[0048] At this time, VCU controller 7 sends a speed of 1000 RPM to lifting controller 3 via CAN communication and controls output port OUT1 to be high. The upper fork lifting solenoid valve 8 is energized and opens, lifting motor 4 runs, and the upper fork lifts independently. Since the goods are stacked in soft packaging, the height of the upper fork rises is uncertain. It is necessary to determine the position of the upper soft packaging pallet. At this time, the status of fork tip detection sensor 16 is first detected. When fork tip detection sensor 16 is continuously triggered, the upper fork rises. When fork tip detection sensor 16 is not triggered, it just sweeps to the bottom of the pallet hole. VCU controller 7 input port IN1 inputs a low level. VCU controller 7 records the height value H1 fed back by upper fork lifting encoder 14 at this moment. The upper fork continues to rise. When fork tip detection sensor 16 is triggered again, it just sweeps to the top of the pallet hole. VCU controller 7 input port IN1 inputs a high level. VCU controller 7 records the height value H2 fed back by upper fork lifting encoder 14 at this moment. At this time, the VCU controller 7 sends a 0 speed signal to the lifting controller 3 via CAN communication and controls the output port OUT1 to be at a low level. The lifting solenoid valve 8 of the upper fork is de-energized and shuts off, the lifting motor 4 stops running, and the upper fork stops running.

[0049] When the VCU controller 7 controls the output port OUT2 to be high, the upper fork descent solenoid valve 9 is energized and opened, and the upper fork descends to the set height (H1-H2) / 2, which is half the height of the pallet hole. The upper fork lifting encoder 14 data is detected. When the difference between the upper fork descending to the set height and the height value fed back by the upper fork lifting encoder 14 is less than or equal to 5mm, the VCU controller 7 controls the output port OUT2 to be low, the upper fork descent solenoid valve 9 is de-energized and closed, and the upper fork stops running.

[0050] When the dual forks are in position, the VCU controller 7 sends a speed of 1000 RPM to the lifting controller 3 via CAN communication and controls the output port OUT5 to be high. The fork forward solenoid valve 12 is energized and opens, the lifting motor 4 starts, and both forks move forward simultaneously. At this time, the status of the upper fork load sensor 17 and the lower fork load sensor 18 is monitored. When both forks have moved forward to the point where both the upper and lower fork load sensors 17 and 18 are triggered, the dual forks are in position. The input ports IN2 and IN3 of the VCU controller 7 are high, the output port OUT5 is low, the fork forward solenoid valve 12 is de-energized and closes, and the VCU controller 7 sends a speed of 0 RPM to the lifting controller 3 via CAN communication, stopping the dual forks from moving forward.

[0051] VCU controller 7 sends a speed of 500 to lifting controller 3 via CAN communication and controls output port OUT3 to be high-level. The lower fork lifting solenoid valve 10 is energized and opens, lifting motor 4 starts running, and both forks lift together. The lower fork load pressure sensor 20 is monitored. Lifting continues until the data fed back from the lower fork load pressure sensor 20 to input port IN5 of VCU controller 7 is greater than 1000. At this point, VCU controller 7 sends a speed of 0 to lifting controller 3 via CAN communication and controls output port OUT3 to be low-level. The lower fork lifting solenoid valve 10 is de-energized and closes, lifting motor 4 stops running, and both forks stop operating simultaneously.

[0052] VCU controller 7 sends a speed of 500 to lifting controller 3 via CAN communication and controls output port OUT1 to a high level. The upper fork lifting solenoid valve 8 is energized and opens, lifting motor 4 starts running, and the upper fork lifts. The upper fork load pressure sensor 19 is monitored. Lifting continues until the data fed back from the upper fork load pressure sensor 19 to input port IN4 of VCU controller 7 is greater than 1000. At this point, VCU controller 7 sends a speed of 0 to lifting controller 3 via CAN communication and controls output port OUT1 to a low level. The upper fork lifting solenoid valve 8 is de-energized and closes, lifting motor 4 stops running, and the upper fork stops operating.

[0053] At this time, VCU controller 7 sends a speed of 1000 to lifting controller 3 via CAN communication and controls the output port OUT6 to be at a high level. The fork retraction solenoid valve 13 is energized and opens, the lifting motor 4 starts running, and both forks move backward simultaneously. After reaching the position, VCU controller 7 sends a speed of 0 to lifting controller 3 via CAN communication and controls the output port OUT6 to be at a low level. The fork retraction solenoid valve 13 is de-energized and closes, the lifting motor 4 stops running, and the picking is completed.

[0054] Release of goods: VCU controller 7 sends a speed of 2000 RPM to the driving controller 5 via CAN communication and controls the output port OUT7 to a low level. This de-energizes the brake relay coil 21, closes the normally closed contact 22 of the brake relay, energizes and releases the electromagnetic brake 23, and starts the driving motor 6, allowing the AGV to run automatically. After the AGV reaches the designated loading station, VCU controller 7 sends a speed of 0 RPM to the driving controller 5 via CAN communication. The driving motor 6 stops running, and simultaneously, VCU controller 7 controls the output port OUT7 to a high level. This energizes the brake relay coil 21, opens the normally closed contact 22 of the brake relay, de-energizes and locks the electromagnetic brake 23, and stops the AGV.

[0055] VCU controller 7 sends a 2000 RPM speed command to lifting controller 3 via CAN communication and controls output port OUT3 to a high level. The lower fork lifting solenoid valve 10 is energized and opens, lifting motor 4 starts running, and both forks lift together. The lower forks continue to lift to the set height of 2300 mm, and the data from the lower fork lifting encoder 15 is monitored. When the difference between the set height and the height value fed back by the lower fork lifting encoder 15 is less than or equal to 5 mm, VCU controller 7 sends a 0 RPM speed command to lifting controller 3 via CAN communication and controls output port OUT3 to a low level. The lower fork lifting solenoid valve 10 is de-energized and closes, lifting motor 4 stops running, and both forks stop operating simultaneously.

[0056] At this time, VCU controller 7 sends a speed of 1000 to lifting controller 3 via CAN communication and controls output port OUT1 to a high level. The upper fork lifting solenoid valve 8 is energized and opens, lifting motor 4 starts running, and the upper fork lifts independently. The upper fork continues to lift to the set height of 3300mm, and the data of the upper fork lifting encoder 14 is detected. When the difference between the upper fork lifting to the set height and the height value fed back by the upper fork lifting encoder 14 is less than or equal to 5mm, VCU controller 7 sends a speed of 0 to lifting controller 3 via CAN communication and controls output port OUT1 to a low level. The upper fork lifting solenoid valve 8 is de-energized and closes, lifting motor 4 stops running, the upper fork stops running, and the lifting is in place.

[0057] VCU controller 7 sends a speed of 1000 to lifting controller 3 via CAN communication and controls output port OUT5 to be at a high level. The fork forward solenoid valve 12 is energized and opens, lifting motor 4 starts running, and both forks move forward simultaneously. After moving forward to the position, VCU controller 7 sends a speed of 0 to lifting controller 3 via CAN communication and controls output port OUT5 to be at a low level. The fork forward solenoid valve 12 is de-energized and closes, and lifting motor 4 stops running.

[0058] When the VCU controller 7's output port OUT4 is at a high level, the lower fork descent solenoid valve 11 is energized and opens, causing both forks to descend simultaneously to a designated height of 2000mm. The values ​​of the lower fork lifting encoder 15 and the lower fork load pressure sensor 20 are then monitored. When the difference between the lower fork's descent to the set height and the height value fed back by the lower fork lifting encoder 15 is less than or equal to 5mm, and the data fed back by the lower fork load pressure sensor 20 to the VCU controller 7's input port IN5 is less than or equal to 100, the VCU controller 7's output port OUT4 is at a low level, the lower fork descent solenoid valve 11 is de-energized and shuts off, and both forks stop operating.

[0059] When the VCU controller 7's output port OUT2 is at a high level, the upper fork descent solenoid valve 9 is energized and opened, allowing the upper fork to descend independently to a specified height of 3000mm. The values ​​of the upper fork lifting encoder 14 and the upper fork load pressure sensor 19 are then monitored. When the difference between the upper fork descending to the set height and the height value fed back by the upper fork lifting encoder 14 is less than or equal to 5mm, and the data fed back by the upper fork load pressure sensor 19 to the VCU controller 7 input port IN4 is less than or equal to 100, the VCU controller 7's output port OUT2 is at a low level. The upper fork descent solenoid valve 9 is de-energized and closed, the upper fork stops operating, and the goods are placed on the shelf.

[0060] At this time, VCU controller 7 sends a speed of 1000 to lifting controller 3 via CAN communication and controls the output port OUT6 to be at a high level. The fork retraction solenoid valve 13 is energized and opens, the lifting motor 4 starts running, and after both forks move backward to their positions simultaneously, VCU controller 7 sends a speed of 0 to lifting controller 3 via CAN communication and controls the output port OUT6 to be at a low level. The fork retraction solenoid valve 13 is de-energized and closes, the lifting motor 4 stops running, and the unloading is completed.

[0061] Although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

[0062] Therefore, the above description is only a preferred embodiment of this application and is not intended to limit the scope of this application; that is, all equivalent modifications made in accordance with the scope of the claims of this application shall be within the protection scope of the claims of this application.

Claims

1. A forward-moving AGV dual-forklift operation control system, characterized in that, include: Lithium battery (1) provides a regulated power supply to the AGV; VCU controller (7) issues operation commands to control the AGV to perform all actions and receives signals from various sensors of the detection module; The hoisting controller (3) is connected to the VCU controller (7) via CAN communication and executes the operation commands issued by the VCU controller (7); The lifting motor (4) realizes the lifting and lowering of the forks as well as the forward and backward movement, and is connected to the lifting controller (3) through a three-phase cable; The driving motor (6) enables the AGV to move forward and backward. The driving controller (5) is connected to the driving motor (6) via a three-phase cable and to the VCU controller (7) via CAN communication; The solenoid valve module controls the flow of hydraulic oil, and controls the lifting, lowering, forward movement, and backward movement of the forks through the pressure of the hydraulic oil. Lifting encoders are used to provide feedback on the lifting height of the forks, namely the upper fork lifting encoder (14) and the lower fork lifting encoder (15). The detection module uses multiple sensors to detect obstacles in front of the forks, load status, and cargo detachment. The braking relay module enables the AGV to stop.

2. The forward-moving AGV dual-forklift operation control system according to claim 1, characterized in that: The solenoid valve module includes: Upper fork lifting solenoid valve (8), upper fork lowering solenoid valve (9), lower fork lifting solenoid valve (10), lower fork lowering solenoid valve (11), fork forward moving solenoid valve (12), fork backward moving solenoid valve (13). When the lower fork lifting solenoid valve (10) or the lower fork lowering solenoid valve (11) is opened, the upper fork and the lower fork move synchronously; when the upper fork lifting solenoid valve (8) or the upper fork lowering solenoid valve (9) is activated, the upper fork moves independently.

3. The forward-moving AGV dual-forklift operation control system according to claim 2, characterized in that: The detection module includes: The fork tip detection sensor (16) is a photoelectric sensor installed at the fork tip position to detect obstacles in front of the fork; The load sensor is an ultrasonic sensor installed at the root of the fork to detect the completion of picking up goods, including the upper fork load sensor (17) and the lower fork load sensor (18). The load pressure sensor is a ring-shaped force sensor installed on the top cylinder of the mast. It outputs an analog signal with a value of 0-2000, detects 0-2 tons of cargo, and is used to determine the cargo detachment from the forks. It includes the upper fork load pressure sensor (19) and the lower fork load pressure sensor (20).

4. The forward-moving AGV dual-forklift operation control system according to claim 3, characterized in that: The braking relay module is a 5-contact intermediate relay, including: The brake relay coil (21) is controlled by the output port of the VCU controller (7); The electromagnetic brake (23) is an electromagnetic friction brake that locks when power is lost. It is installed on the rotating shaft of the driving motor (6) and stops the AGV by locking the rotation of the driving motor (6). It is controlled by the output port of the VCU controller (7). The normally closed contact (22) of the brake relay is connected in the circuit of the electromagnetic brake (23).

5. The forward-moving AGV dual-forklift operation control system according to claim 1, characterized in that: The lifting controller (3) and the travel controller (5) are both AC controllers, and the lifting motor (4) and the travel motor (6) are both AC motors; the lifting encoder is a CAN absolute encoder.

6. A method for controlling the operation of a forward-moving AGV with dual forks as described in any one of claims 1-5, characterized in that, Includes the following steps: S1: First, the VCU controller (7) controls the AGV to run to the pickup station via CAN communication; S2: The VCU controller (7) controls the lower fork lifting solenoid valve (10) to open via CAN communication, and both forks are lifted together. After the lower fork is lifted to the set height and passes the test, both forks stop running together. S3: The VCU controller (7) controls the opening of the upper fork lifting solenoid valve (8) through CAN communication. The upper fork is lifted to the set height by itself. After the height is detected as qualified, the upper fork stops running. S4: After the double forks are raised to the position, the VCU controller (7) controls the fork forward movement solenoid valve (12) to be energized and opened through CAN communication, and the double forks move forward at the same time; at this time, the status of the upper fork load sensor (17) and the lower fork load sensor (18) is detected. When both are triggered, the double forks stop moving forward. S5: The VCU controller (7) controls the lower fork lifting solenoid valve (10) to be energized and open, and the two forks lift together. The lifting continues until the upper fork load pressure sensor (19) and the lower fork load pressure sensor (20) provide qualified data to the input port of the VCU controller (7), at which point the two forks stop running together. S6: The VCU controller (7) controls the fork retraction solenoid valve (13) to be energized and opened via CAN communication, the lifting motor (4) runs, and both forks move backward at the same time. After reaching the position, the fork retraction solenoid valve (13) is de-energized and shut off, and the picking is completed. S7: The VCU controller (7) controls the electromagnetic brake (23) to be energized and released, the travel motor (6) to run, and after the AGV runs to the designated delivery station, the VCU controller (7) controls the travel motor (6) to stop running, the electromagnetic brake (23) to be de-energized and locked, and the AGV to stop running; the VCU controller (7) controls the fork forward solenoid valve (12) to be energized and opened through CAN communication, and the two forks move forward at the same time. After moving forward to the position, the fork forward solenoid valve (12) is de-energized and shut off; S8: The VCU controller (7) controls the lower fork descent solenoid valve (11) to be energized and open. The two forks descend to the specified height at the same time. The values ​​of the lower fork lifting encoder (15) and the lower fork weight pressure sensor (20) are detected. After the values ​​are qualified, the VCU controller (7) controls the lower fork descent solenoid valve (11) to be de-energized and shut off, and the two forks stop running. The VCU controller (7) controls the upper fork descent solenoid valve (9) to be energized and open, the upper fork descends, and detects the data of the upper fork load pressure sensor (19). When the upper fork load pressure sensor (19) feeds back the data to the input port of the VCU controller (7) and the value is qualified, it means that the upper fork has descended to the specified position, and the VCU controller (7) controls the upper fork to stop descending. S9: The VCU controller (7) controls the fork retraction solenoid valve (13) to be energized and opened via CAN communication. Both forks move backward simultaneously. After reaching the position, the VCU controller (7) controls the fork retraction solenoid valve (13) to be de-energized and shut off, the lifting motor (4) stops running, and the unloading is completed.

7. The forward-moving AGV dual-fork operation control method according to claim 6, characterized in that: In step S2, the qualified standard for detection is: the lower fork is continuously raised to the set height of 2000mm, and the data of the lower fork lifting encoder (15) is detected. The difference between the lower fork raised to the set height and the height value fed back by the lower fork lifting encoder (15) is less than or equal to 5mm.

8. The forward-moving AGV dual-fork operation control method according to claim 6, characterized in that: In step S3, the qualified standard for detection is: the upper fork is continuously raised to a set height of 3000mm, and the data of the upper fork lifting encoder (14) is detected. The difference between the upper fork being raised to the set height and the height value fed back by the upper fork lifting encoder (14) is less than or equal to 5mm.

9. The forward-moving AGV dual-fork operation control method according to claim 6, characterized in that: In step S5, the data of the upper fork load pressure sensor (19) and the lower fork load pressure sensor (20) are detected. When the data fed back from the upper fork load pressure sensor (19) and the lower fork load pressure sensor (20) to the input port of the VCU controller (7) is greater than 1000, both forks stop running together.

10. The forward-moving AGV dual-fork operation control method according to claim 6, characterized in that: In step S8, when the lower fork descends to a specified height of 50mm, the values ​​of the lower fork lifting encoder (15) and the lower fork load pressure sensor (20) are detected. When the difference between the lower fork descending to the set height and the height value fed back by the lower fork lifting encoder (15) is less than or equal to 5mm, and the data fed back by the lower fork load pressure sensor (20) to the input port of the VCU controller (7) is less than or equal to 100, the VCU controller (7) controls the lower fork descent solenoid valve (11) to de-energize and shut off, and the double forks stop running. At this time, the data of the upper fork load pressure sensor (19) is detected. When the data fed back by the upper fork load pressure sensor (19) to the input port of the VCU controller (7) is less than or equal to 100, it indicates that the upper fork has descended to the specified position.

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