A stacking picking and placing control method, system, device and storage medium

Abstract

The present invention relates to the technical field of stackers, and particularly relates to a stacker loading and unloading control method, system, device and storage medium. During the process of picking up or placing goods, before the fork extends in place, the hoist motor brake is opened, zero-speed hovering is performed, and the excitation state is maintained; during the process of the hoist motor lifting or lowering the load platform, the fork motor keeps the brake on and does not close, and is in the excitation state; wherein, when the position of the load platform is offset, the hoist motor pulls the load platform to adjust in real time to keep the load platform at the set position. By means of zero-speed hovering, the present invention changes the sequential execution of the operations of the two axes of hoisting and the fork into parallel operation, reduces the time wasted in loading and unloading goods, improves the loading and unloading efficiency, improves the single-machine efficiency of the stacker without changing the hardware cost, or reduces the power of the hoist and horizontal motors due to the reduction of the fork cycle time under the condition of unchanged efficiency, and further reduces the selection of frequency converters, motor protectors, cables, etc., so as to achieve cost reduction.

Description

Technical Field

[0001] The present invention relates to the technical field of stackers, and particularly relates to a stacker goods taking and placing control method, system, device and storage medium. Background Art

[0002] In the prior art, the logic process of the goods taking of a roadway stacker is as follows: the horizontal mechanism and the lifting mechanism of the stacker move to the target position, the horizontal mechanism is closed, and the brake of the lifting motor is engaged. The brake of the fork is released, the fork extends, and the brake is closed after moving in place; the lifting motor is excited, the brake is released, the load platform is pulled up slightly to the high position, and the brake of the lifting motor is closed; after the goods are taken, the brake of the fork motor is released, the fork retracts, and the brake is closed after the fork retracts in place.

[0003] According to the goods taking / putting process, the fork and the lifting are executed sequentially. Since there is positioning overshoot when the fork shaft or the lifting shaft moves, after the movement positioning of the fork shaft or the lifting shaft is completed, the operation of the next shaft can continue. During one goods taking / putting time, the motor brake needs to be closed 4 times and opened 3 times. However, the operations of opening and closing the brake will cause delays for each action due to signal transmission, mechanical opening or closing, etc. Moreover, the different opening times of the motor brake will affect the efficiency of the goods taking / putting time. The lifting motor is usually large, and it takes a longer time to open the brake (usually 1 - 2 s). Therefore, the longer goods taking / putting time of the fork will lead to a reduction in the single-machine efficiency of the stacker.

[0004] In the prior art, to solve this problem, it is usually compensated by increasing the maximum speed and acceleration of the horizontal mechanism and the lifting mechanism, and a lifting motor with a larger power size needs to be selected, which results in an increase in the selection of the frequency converter, motor protector, cable, etc., leading to an increase in the overall cost.

[0005] Based on the problems existing in the prior art, the present invention provides a stacker goods taking and placing control method, system, device and storage medium. Summary of the Invention

[0006] The object of the present invention is to provide a stacker goods taking and placing control method, system, device and storage medium to solve the technical problem that in the prior art, the fork motor and the lifting motor are executed sequentially, resulting in action delays and low goods taking and placing efficiency.

[0007] The technical solution of the present invention is: a stacking pick-and-place control method, including: during the process of picking up or placing goods, before the fork extends in place, the hoist motor brake is opened; during the process of the fork extending to pick up goods and retracting, the hoist motor maintains the excitation state and performs zero-speed hovering; during the operation of the hoist motor to lift or lower the load platform, the fork motor maintains the brake, does not close, and is in the excitation state; wherein, during the process of picking up or placing goods, when the position of the load platform deviates, the hoist motor pulls the load platform to adjust in real time to keep the load platform at the set position; when the fork opens the brake and during the process of the fork extending or retracting, calculate the deviation between the load platform and the set position; the hoist motor pulls the load platform to adjust to the set position in real time, wherein, if the offset of the load platform exceeds 5 millimeters, an alarm is given and the operation is stopped.

[0008] Preferably, the process of picking up goods is as follows:

[0009] Q1: After the horizontal mechanism and the hoist motor reach the position, the hoist motor does not close the brake and performs zero-speed hovering;

[0010] Q2: The fork motor opens the brake, the fork extends, and after the fork extends in place, the fork motor does not close the brake and performs zero-speed hovering;

[0011] Q3: After the fork extends in place, the load platform is lifted, and after lifting in place, the hoist motor does not close the brake and performs zero-speed hovering;

[0012] Q4: After the load platform is slightly lifted in place, the fork retracts, and after the fork retracts in place, the brakes of the hoist motor and the fork motor are closed.

[0013] Preferably, the process of placing goods is as follows:

[0014] F1: The horizontal mechanism and the hoist motor do not close the brake and perform zero-speed hovering;

[0015] F2: After the hoist motor reaches the position, the fork opens the brake, the fork extends, and after the fork extends in place, the fork motor does not close the brake and performs zero-speed hovering;

[0016] F3: After the fork extends in place, the load platform descends, and after descending in place, the hoist motor does not close the brake and performs zero-speed hovering;

[0017] F4: After the load platform descends in place, the fork retracts, and after the fork retracts in place, the brakes of the hoist motor and the fork motor are closed.

[0018] Preferably, during the process of lifting the load platform, set the average acceleration a of lifting u 、the maximum speed v u 、the initial speed and the final speed are 0, and the running distances from 0 to the maximum speed and from the maximum speed to 0 are The running times from 0 to the maximum speed and from the maximum speed to 0 are The time of uniform motion is The minimum distance for the forklift to lift until it touches the lower surface of the goods Then,

[0019] If Then Distance formula:

[0020]

[0021] If According to the distance formula:

[0022] Calculate the minimum time required to reach the allowable lifting height. If the forklift overshoots or moves back during the required minimum time, it is regarded as safe; if it exceeds the required minimum time and the forklift still does not reach the set position, the movement is stopped and an alarm is prompted.

[0023] Preferably, during the descent of the loading platform, the set average acceleration a d , the maximum speed v d , the initial speed and the final speed are 0, and the running distances from 0 to the maximum speed and from the maximum speed to decelerate to 0 are The running time from 0 to the maximum speed and from the maximum speed to decelerate to 0 is The time of uniform motion is The minimum distance for the forklift to lift until it touches the lower surface of the goods The minimum time

[0024] If Then Distance formula:

[0025]

[0026] If According to the distance formula Then,

[0027] Calculate the minimum time required to reach the allowable descent height. If the forklift overshoots or moves back during the required minimum time, it is regarded as safe; if it exceeds the required minimum time and the forklift still does not reach the set position, an alarm is prompted and the operation is stopped.

[0028] A stacker loading and unloading control system for implementing the described stacker loading and unloading control method, comprising:

[0029] A detection unit that detects the real-time position, speed, and acceleration of the loading platform;

[0030] A data processing unit calculates the distance deviation between the real-time position of the loading platform and the set position based on the real-time position of the loading platform; and calculates the shortest time required for the forklift to pick up or place goods according to the operating state of the forklift.

[0031] A control unit, a detection unit, a data processing unit, a forklift motor, and a lifting motor are electrically connected to the control unit respectively.

[0032] The control unit controls the operation of the forklift motor or zero-speed hovering through instructions, and the forklift motor drives the forklift to extend or retract; the control unit controls the operation of the lifting motor through instructions to pull and adjust the loading platform to maintain at the set position; the control unit determines whether the forklift reaches the set position within the shortest time required for the forklift to pick up or place goods. When the forklift does not reach the set position, an alarm is prompted, and the forklift motor and the lifting motor are controlled to stop running.

[0033] An electronic device, the device includes a processor and a memory, and at least one instruction or at least one program segment is stored in the memory, and the at least one instruction or at least one program segment is loaded and executed by the processor to implement the described stacker picking and placing control method.

[0034] A computer-readable storage medium stores at least one instruction or at least one program segment, and the at least one instruction or the at least one program segment is loaded and executed by a processor to implement the described stacker picking and placing control method.

[0035] Compared with the prior art, the advantages of the present invention are:

[0036] (1) In the embodiment of the present invention, through the zero-speed hovering method, the lifting and forklift motors are changed from sequential execution to parallel operation. When one axis (forklift axis or lifting axis) operates, the other axis does not simply wait for the previous process to complete, but the preparatory work before the action is completed in advance, so as to implement the parallel operation of the two axes, saving the motor on and off brake time during sequential execution. The parallel operation of the forklift axis and the lifting axis makes the picking and placing actions of the stacker more smooth, reduces the pause time caused by sequential execution, and improves the picking and placing efficiency.

[0037] (2) The single-machine efficiency of the stacker is mainly affected by the speed and acceleration of lifting and horizontal movement as well as the picking / placing time. By reducing the picking / placing time, the acceleration and speed of horizontal and lifting movements can be reduced. Without changing the hardware cost, the single-machine efficiency of the stacker can be improved, or in the case of unchanged efficiency, due to the reduction of the forklift cycle time, the power of the lifting and horizontal motors can be reduced, and then the models of related components such as frequency converters, motor protectors, and cables can be reduced to achieve cost reduction.

[0038] (3) If there is a slight overshoot during the lifting or fork movement, it will not affect the movement of the next axis and will not affect the overall efficiency, increasing the stability of the mechanical operation.

[0039] (4) When the rigidity of the load platform device is insufficient and the fork moves with a load, causing the load platform to shift, the lifting axis can adjust the load platform to the set position in real time without affecting the normal operation of the fork axis. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] The present invention will be further described below in conjunction with the drawings and embodiments:

[0041] Figure 1 It is a flowchart of the method for the stacker fork to pick up goods according to the present invention;

[0042] Figure 2 It is a flowchart of the method for the stacker fork to place goods according to the present invention;

[0043] Figure 3 It is a block diagram of the stacker pick-up and placement control system according to the present invention;

[0044] Figure 4 It is a diagram comparing the efficiencies of different fork cycle times in the first embodiment of the present invention;

[0045] Figure 5 It is a schematic diagram comparing the influence of different fork cycle times on the lifting level requirements under the same efficiency in the first embodiment of the present invention;

[0046] Figure 6 It is a diagram comparing the efficiencies of different fork cycle times in the second embodiment of the present invention;

[0047] Figure 7 It is a schematic diagram comparing the influence of different fork cycle times on the lifting level requirements under the same efficiency in the second embodiment of the present invention;

[0048] Figure 8 It is a schematic diagram of the fork picking up goods in the embodiment of the present invention;

[0049] Figure 9 It is a schematic diagram of the fork placing goods in the embodiment of the present invention;

[0050] Among them: 1. Goods; 2. Shelf; 3. Fork. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0051] The content of the present invention will be further described in detail below in conjunction with specific embodiments:

[0052] At present, the pick-up / put-down logic of the stacker is as follows: when the stacker moves horizontally and vertically to the target position, during the extension and retraction of the fork, each time an action is executed, the brake needs to be closed or opened. When closing or opening the brake, due to the time required for signal transmission and mechanical closing actions, there will be action delays. Four times of closing the motor brake and three times of opening the motor brake are required within one pick-up / put-down time. Each delayed action will result in a longer cycle time for a single machine and low efficiency.

[0053] The embodiment of the present invention provides a stacker pick-up / put-down control method, including: a complete pick-up process and a complete put-down process. As Figure 1 shown, the pick-up process is as follows:

[0054] Q1: After the horizontal mechanism and the hoisting motor reach the position, the hoisting motor does not close the brake and performs zero-speed hovering (the motor still outputs torque);

[0055] Q2: The fork motor opens the brake and the fork extends.

[0056] Before the fork extends in place, the hoisting brake is opened. In the hoisting direction, due to the action of gravity, the load platform will move downward, and if there is an abnormality that causes the load platform to shift (such as insufficient rigidity of the load platform). At this time, although the hoisting motor is at zero speed, it still outputs torque and is in the excitation state. Once the load platform shifts, the hoisting motor can pull the load platform to adjust in real time and keep the load platform at the set position. If the offset amount of the load platform exceeds 5 mm is detected during this process, an alarm will be issued.

[0057] After the fork extends in place, the fork motor does not close the brake and performs zero-speed hovering (the motor still outputs torque) and is in the excitation state.

[0058] Q3: After the fork extends in place, the hoisting motor runs to drive the load platform to lift.

[0059] Before the fork reaches the position, the hoisting motor brake is opened and is in the excitation state. After the fork reaches the position, the hoisting motor does not need to spend time opening the brake again and immediately runs to lift slightly upward, saving the time for the hoisting motor to open the brake. At this time, calculate the shortest time for the fork to run to contact the goods.

[0060] Since there are many shelves in the warehouse, when the fork is at zero-speed hovering and the brake pauses, there will be a slight displacement fluctuation. Therefore, there is a difference in the distance between the fork and the lower surface of the goods each time the fork extends (ideally, the distance between the fork and the goods is equal each time the fork extends). The distance value fluctuates within a range. If the shortest time for the fork to run and contact the goods is used as a benchmark to confirm whether the fork contacts the goods (or the pallet carrying the goods), the fork is allowed to move within this time and will definitely contact the pallet. If the fork moves beyond the shortest time, an alarm will be issued (after the fork moves in place within the specified time, the position is locked and no further movement is allowed).

[0061] Specifically, during the process of lifting the loading platform, the average acceleration a of the lift is set u , the maximum speed v u , the initial speed and the final speed are 0, and the running distances from 0 to the maximum speed and from the maximum speed to 0 are The running times from 0 to the maximum speed and from the maximum speed to 0 are The uniform motion time is The minimum distance for the forklift to lift until it touches the lower surface of the goods The minimum distance Is a determined value, refer to the appendix Figure 8 A schematic diagram of the motion posture of the forklift when picking up goods is provided. The spacing ① in the figure indicates the moving distance when the forklift 3 touches the goods 1 during picking up goods. The forklift can freely expand and contract within this distance. Then, during the picking up process, the running state of the forklift is as follows:

[0062] If Then the lifting action first accelerates uniformly from 0 to the maximum speed v u , then moves at a constant speed with the maximum speed v u , and finally decelerates from the maximum speed v u To 0;

[0063] Distance formula:

[0064]

[0065] If Then the lifting action first accelerates uniformly from 0 and decelerates to 0 before reaching the maximum speed. According to the distance formula: Calculate the shortest time required to reach the allowable lifting height.

[0066] Due to problems such as old forklift machinery and electrical parameters, overshoot or retraction occurs, causing the forklift to be outside the set position range. Since the forklift is always in the excited state, it can still continue to run and adjust to the set position without interrupting the overall process. Therefore, if overshoot or backward movement occurs within the required shortest time, it is considered safe; if the forklift still has not reached the set position after exceeding the required shortest time, the movement stops and an alarm is prompted.

[0067] After lifting in place, the hoisting motor does not close the brake and performs zero-speed hovering;

[0068] Q4: After the loading platform is slightly lifted in place, the forklift forks are retracted.

[0069] The time when the forklift forks release the brake coincides with the time of slight lifting. After the slight lifting is in place, the forklift fork motor is in the excited state,

[0070] Therefore, the fork motor does not need to spend time opening the brake again and can immediately perform the fork retraction movement, saving the time for the fork motor to open the brake. To prevent the load platform from tilting, as the goods move with the fork and the speed of the fork is 0 at this time, the output torque is not 0.

[0071] Due to mechanical aging and problems such as motor parameters, the overshoot or retraction of the load platform causes it to be outside the set range. Therefore, at this time, calculate the maximum allowable deviation of the load platform. If there are abnormalities (such as heavy goods and insufficient rigidity of the load platform) causing the load platform to shift, during the fork retraction process, if the load platform is within the maximum allowable deviation range, it continues to move. Synchronously, the lifting motor remains in the excited state all the time and can pull and adjust the position of the load platform in real time without interrupting the overall process. However, if the offset of the load platform exceeds 5 mm during this process, an alarm will be given and the operation will stop.

[0072] After the fork retracts in place, close the brakes of the lifting motor and the fork motor.

[0073] Refer to Appendix Figure 2 , and the process of discharging goods is as follows:

[0074] F1: After the horizontal mechanism and the lifting motor run to the target position, the lifting motor does not close the brake and performs zero-speed hovering (the motor still outputs torque).

[0075] F2: After the lifting motor reaches the position, the fork opens the brake and the fork extends.

[0076] Before the fork extends in place, synchronously open the lifting brake. Although the lifting motor has zero speed, it still outputs torque and the motor remains in the excited state all the time. In the lifting direction, due to the action of gravity, the load platform moves downward, resulting in the deviation of the load platform position. Or at this time, there are abnormalities (such as heavy goods and insufficient rigidity of the load platform) causing the load platform to shift. Once the load platform shifts, the lifting motor can pull and adjust the load platform to the set position in real time. If it is detected that the offset of the load platform exceeds 5 mm during this process, an alarm will be given.

[0077] After the fork extends in place, the fork motor does not close the brake and performs zero-speed hovering (the motor still outputs torque).

[0078] F3: After the fork extends in place, the brake of the fork motor is not closed. To prevent the load platform from tilting, as the goods move with the fork and the speed of the fork is 0 at this time, the output torque is not 0.

[0079] The time for the lifting brake to open coincides with the running time of the fork. After the fork runs in place, since the lifting motor is in the excited state, the lifting motor does not need to spend time opening the brake again and can run immediately to drive the load platform to descend, saving the time for the lifting brake to open.

[0080] During the descent of the load platform, set the average acceleration a for descentd 、Maximum speed v d 、The initial speed and the final speed are 0, and the running distances from 0 to the maximum speed and from the maximum speed to decelerate to 0 are S d0 、The running times from 0 to the maximum speed and from the maximum speed to decelerate to 0 are t d1 、The uniform motion time is t d2 、The minimum distance S for the forklift forks to lift until they contact the lower surface of the goods dmin 1 ; The minimum distance S dmin 1 is a determined value, refer to Appendix Figure 9 , contrary to picking up goods, when putting down goods, a schematic diagram of the movement posture of the forklift forks is provided. The spacing ③ in the figure represents the distance where the goods contact the shelf, and the forklift forks can freely stretch and move within this distance.

[0081] If then the lifting action first accelerates uniformly from 0 to the maximum speed v d , then moves at a constant speed with the maximum speed v d , and finally decelerates from the maximum speed v d to 0;

[0082] Distance formula:

[0083]

[0084] If then the lifting action first accelerates uniformly from 0 and decelerates to 0 before reaching the maximum speed;

[0085] According to the distance formula then,

[0086] calculate the shortest time required to reach the allowable descent height.

[0087] Problems such as old forklift fork machinery and electrical parameters are likely to cause overshoot or backlash, making the forklift forks not within the set position range. Since the forklift forks are always in the excited state, they can still continue to run and adjust to the set position without interrupting the overall process. Therefore, the shortest time is used to confirm that the forklift forks contact the goods (or the pallet carrying the goods). Within the required shortest time, the forklift forks are allowed to move, and overshoot or reverse movement of the forklift forks is regarded as safe; however, if the forklift forks still do not reach the set position after exceeding the required shortest time, or the forklift forks move after exceeding the required shortest time, an alarm prompt will be given.

[0088] After descending to the in-place position, the hoisting motor does not close the brake and performs zero-speed hovering. Since the fork motor is in the excited state, there is no need to spend time opening the brake again, and the fork retraction movement can be executed. This saves the time for the fork motor to open the brake. At this time, the deviation between the real-time position and the set position of the load platform is calculated again, especially the maximum allowable deviation. During the process of fork retraction and reset, if the load platform is within the maximum allowable deviation range, it can continue to run without interrupting the whole process.

[0089] F4: After the load platform descends to the in-place position, the forks are retracted.

[0090] During the process of fork retraction, if the position of the load platform shifts (such as insufficient rigidity of the load platform), the hoisting motor will pull the load platform to adjust in real time. If the deviation of the load platform exceeds 5 mm, an alarm will be given and the operation will be stopped.

[0091] After the forks are retracted to the in-place position, close the brakes of the hoisting motor and the fork motor.

[0092] Further, referring to the appendix Figure 3 , this embodiment provides a stacker loading and unloading control system for implementing the above stacker loading and unloading control method, including:

[0093] A detection unit for detecting the real-time position, speed, and acceleration of the load platform;

[0094] A data processing unit for calculating the distance deviation between the real-time position of the load platform and the set position according to the real-time position of the load platform; and calculating the shortest time required for the forks to pick up or place goods according to the running state of the forks;

[0095] A control unit, the detection unit, the data processing unit, the fork motor, and the hoisting motor are electrically connected to the control unit respectively;

[0096] The control unit controls the fork motor to run or perform zero-speed hovering through instructions, and the fork motor drives the forks to extend or retract; the control unit controls the hoisting motor to run through instructions and pulls and adjusts the load platform to maintain it at the set position; the control unit judges whether the forks reach the set position within the shortest time required for the forks to pick up or place goods. When the forks do not reach the set position, an alarm is given, and the fork motor and the hoisting motor are controlled to stop running.

[0097] In the embodiment of the present invention, by means of zero-speed hovering, the time for opening and closing the brake is avoided. When one axis (fork axis or hoisting axis) runs, the other axis does not simply wait for the previous process to complete, but the preparatory work before the action is completed in advance, and the fork axis and the hoisting axis run in parallel, making the loading and unloading actions of the stacker more smooth, reducing the pause time caused by sequential execution, and improving the loading and unloading efficiency.

[0098] The single-machine efficiency of the stacker is mainly affected by the lifting speed, horizontal speed and acceleration, and the pick-up / put-down time of the fork. A long pick-up / put-down time of the fork will reduce the single-machine efficiency of the stacker. It can only be compensated by increasing the maximum horizontal and lifting speeds and accelerations. At this time, the selection of the horizontal and lifting motors will be larger, resulting in larger selections for the frequency converter, motor protector, cable, etc., leading to an increase in the overall cost.

[0099] In one implementation (Example 1), Project 1 is provided, and the project scenario conditions are as follows:

[0100] The movable length of the stacker in the horizontal direction (X-axis direction) is 80 meters, the initial horizontal speed is 160 m / min (the motor accelerates from zero to the maximum speed, i.e., the rated speed of the motor), and the horizontal acceleration is 0.5 m / s 2 (where a x and b x represent the accelerations corresponding to acceleration and deceleration in the horizontal direction); the height of the stacker in the lifting direction (Y-axis direction) is 20 meters, the maximum vertical speed is 40 m / min (the lifting motor accelerates from zero to the maximum speed, i.e., the rated speed of the motor), and the vertical acceleration is 0.5 m / s 2 (a y and b y respectively represent the accelerations corresponding to acceleration and deceleration in the vertical direction).

[0101] Referring to the appendix Figure 4 , a comparison chart of the cycle efficiency and required time of different forks is provided, which specifically shows the efficiency and corresponding required time for a single cycle, as well as the efficiency and corresponding required time for a compound cycle.

[0102] Among them, a single cycle refers to the journey of the fork to take out the goods from the shelf and send them outside the shelf, or to take down the goods from outside the shelf and send them into the shelf. A compound cycle refers to the journey of taking out the goods from the shelf and sending them to an uncertain position outside the shelf, and then taking the goods in the outside area of the shelf and sending them into the shelf.

[0103] The journey of the compound cycle is longer than that of the single cycle, the route is more complex, and the required time is longer. In this implementation, the zero-speed hovering method is adopted, which can save the time of opening and closing the brake, and the compound cycle efficiency is higher.

[0104] Referring to the appendix Figure 5 , for Project 1 in this example, the single cycle efficiency is set to be fixed (48 Tu / h), the compound cycle efficiency is fixed (58 Tu / h), and under the premise of the same horizontal length L = 80 m and lifting length of 20 m, the same single cycle efficiency, required cycle time, and the requirements for the horizontal and lifting speeds and accelerations of the fork are achieved.

[0105] Taking the data in the first column and the sixth column as examples, in the data of the first column, the horizontal speed is 160 m / min and the acceleration is 0.5 m / s 2 , the lifting speed is 40 m / min and the lifting acceleration is 0.5 m / s 2 , and the required cycle time is 14 s; in the data of the sixth column, the horizontal speed is 120 m / min and the horizontal acceleration is 0.5 m / s 2 , the lifting speed is 36 m / min and the lifting acceleration is 0.5 m / s 2 , and the required cycle time is 9 s. Through comparative analysis, it can be seen that it is still possible to achieve the desired cycle efficiency without the need for high horizontal and lifting speeds, and the cycle time is reduced, the efficiency is improved, which is particularly obvious in the changes of the horizontal speed and acceleration.

[0106] In this embodiment, without changing the cost, the single-cycle and compound-cycle efficiencies (the efficiency unit is: Tu / h, representing the number of pallet transfers per hour) increase by 15% and 21% respectively. And when the efficiency remains unchanged, the horizontal speed can be reduced by 25%, the acceleration can be reduced by 40%, and the lifting speed can be reduced by 10%, reducing the high requirements for related components such as frequency converters, motor protectors, and cables, no longer being limited to high-cost devices or equipment, and reducing costs.

[0107] In another embodiment, Project 2 is provided, and the scenario conditions of this project are:

[0108] The stacker can move horizontally (in the X-axis direction) with a length of 30 meters, the maximum horizontal speed is 160 m / min (accelerating from zero to the maximum speed, that is, the rated speed of the motor), and the horizontal acceleration is 0.5 m / s 2 ; in the lifting direction (Y-axis direction), the height is 6 meters, the maximum vertical speed is 40 m / min, and the vertical acceleration is 0.5 m / s 2 .

[0109] Referring to the Figure 6 , the efficiency comparison chart of different fork cycle times, which specifically shows the efficiency of a single cycle and the corresponding required time, as well as the efficiency of a compound cycle and the corresponding required time.

[0110] Referring to the Figure 7 , in this embodiment - Project 2, it is set that the single-cycle efficiency is fixed (74 Tu / h) and the compound-cycle efficiency is fixed (82 Tu / h). Under the premise of the same scenario with a horizontal length L = 20 m and a lifting length of 6 m, the same single-cycle efficiency, required cycle time, and the requirements for the horizontal and lifting speeds and accelerations of the forks are achieved.

[0111] Taking the data in the first column and the sixth column as examples, in the data of the first column, the horizontal speed is 160 m / min and the acceleration is 0.5 m / s2 , the lifting speed is 40 m / min, and the lifting acceleration is 0.5 m / s 2 , the cycle time is 14 s; in the sixth column of data, the horizontal speed is 90 m / min, and the horizontal acceleration is 0.3 m / s 2 , the lifting speed is 20 m / min, and the lifting acceleration is 0.5 m / s 2 , and the required cycle time is 9 s. Through comparative analysis, it can be seen that it is still possible to achieve the desired cycle efficiency without the need for high horizontal and lifting speeds, and the cycle time is reduced, and the efficiency is improved, which is particularly obvious in the changes of the horizontal speed and acceleration.

[0112] It can be seen that when the cost remains unchanged, the efficiency of single-cycle and compound-cycle increases by 27% and 29% respectively; and when the efficiency remains unchanged, the horizontal speed can be reduced by 44%, the acceleration can be reduced by 40%, and the lifting speed can be reduced by 50%.

[0113] Generally, the motor accelerates from zero to the maximum speed (rated speed) to drive the fork to run. The higher the initial speed requirements for speed and acceleration (the larger the value), the more restricted the motor selection is. And in this embodiment, by setting the zero-speed hover mode, the cycle time can be shortened, the efficiency can be improved, and the requirements for the speed and acceleration of the motor are reduced, the motor selection requirements are reduced, the selection options are broadened, and the efficiency is significantly improved at a small cost, so as to achieve the efficiency of cost reduction and efficiency increase.

[0114] Therefore, in the embodiment of the present invention, by reducing the pick-up / put-down time, reducing the acceleration and speed of horizontal and lifting, the power of the lifting and horizontal motors is reduced, and then the specifications of a series of components such as inverters, motor protectors, and cables are reduced, so as to achieve cost reduction.

[0115] When there is a minor overshoot during the lifting or fork running process, it will not affect the movement of the next axis and will not affect the overall efficiency, improving the stability of the equipment operation. For example: when there is an overshoot after the fork extends in place during picking but does not exceed the limit, the lifting axis can still run at this time. Under this control mode, the fork will always move towards the set position, so the fork will continue to move to the target position after overshooting when the lifting axis is lifted (the overshoot can be limited on the premise that the overshoot does not exceed the limit).

[0116] Since the lifting motor is in a stationary state when the fork extends, when the fork moves with a load, the rigidity of the load-carrying platform device is insufficient, and the position may shift. In the light case, the running logic of the fork is interrupted and the stacker alarms and stops. In the heavy case, the goods may rub against the shelf crossbeam and the goods may fall.

[0117] Moreover, when the goods are heavy, if the offset of the loading platform exceeds the set value after the fork carries the load and extends, the stacker will not be able to proceed to the next step.

[0118] In the embodiment of the present invention, when the rigidity of the loading platform device is insufficient and the fork moves with a load, causing the loading platform to shift, the lifting motor hovers at zero speed and maintains the excitation state, and the lifting shaft adjusts the current position of the loading platform to the set position in real time, without affecting the normal operation of the fork shaft.

[0119] The embodiment of the present invention also provides an electronic device, which includes a processor and a memory; the memory stores one or more instructions, and the one or more instructions are suitable for being loaded and executed by the processor to implement a stacker loading and unloading control method as in the above method embodiment.

[0120] The memory can be used to store software programs and modules. The processor runs the software programs and modules stored in the memory to perform various functional applications and data processing. The memory mainly includes a program storage area and a data storage area. Among them, the program storage area can store an operating system, application programs required for functions, etc.; the data storage area can store data created according to the use of the device, etc. In addition, the memory can include high-speed random access memory, and can also include non-volatile memory, such as at least one magnetic disk storage device, a flash memory device or other volatile solid-state storage devices. Correspondingly, the memory can also include a memory controller to provide the processor with access to the memory.

[0121] The internal structure of the electronic device provided by the embodiment of the present invention can include, but is not limited to: a processor, a memory, and a communication interface. The processor, memory, and communication interface in the electronic device can be connected through a bus or other means. In the embodiment of this specification, taking the connection through a bus as an example.

[0122] Among them, the processor (or CPU, Central Processing Unit) is the computing core and control core of the electronic device. The communication interface is used for communication between the memory and the processor. The memory is used to store programs and data. It can be understood that the memory here can be a high-speed RAM storage device or a non-volatile memory device, such as at least one disk storage device; optionally, it can also be at least one storage device located far from the aforementioned processor. The memory provides a storage space, and the operating system of the electronic device is stored in this storage space, which can include but is not limited to: Windows system (an operating system), Linux system (an operating system), etc., and the present invention does not make any limitations in this regard; moreover, a computer program (including program code) suitable for being loaded and executed by the processor is also stored in this storage space. In the embodiments of this specification, the processor loads and executes the computer program stored in the memory to implement a stacking loading and unloading control method provided by the above method embodiments.

[0123] The embodiments of the present invention also provide a computer-readable storage medium. The storage medium can be set in the electronic device to store at least one instruction, at least one program, a code set or an instruction set related to implementing the AGV scheduling method in the photovoltaic cell workshop in the method embodiments. The at least one instruction, at least one program, a code set or an instruction set can be loaded and executed by the processor of the electronic device to implement a stacking loading and unloading control method provided by the above method embodiments.

[0124] Optionally, in this embodiment, the above storage medium can include but is not limited to: USB flash drive, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), mobile hard disk, magnetic disk or optical disc and other various media that can store program code.

[0125] It should be noted that: the above sequence of the embodiments of the present invention is only for description and does not represent the superiority or inferiority of the embodiments. Moreover, the above specific embodiments of this specification are described, and other embodiments are within the scope of the appended claims. In some cases, the actions or steps recorded in the claims can be executed in a different order from that in the embodiments and still achieve the desired results. Additionally, the processes depicted in the drawings do not necessarily require to be executed in the specific order or continuous order shown to achieve the desired results. In certain embodiments, multi-task processing and parallel processing are also possible or may be advantageous.

[0126] Each embodiment in this specification is described in a progressive manner. For the same or similar parts among the embodiments, reference can be made to each other, and the differences between each embodiment and other embodiments are emphasized. In particular, for the apparatus embodiments, since they are basically similar to the method embodiments, they are described relatively simply, and reference can be made to the corresponding parts of the method embodiments for relevant content.

[0127] Those of ordinary skill in the art can understand that all or part of the steps to implement the above embodiments can be completed by hardware, or can be completed by a program instructing relevant hardware. The program can be stored in a computer-readable storage medium, and the above-mentioned storage medium can be a read-only memory, a magnetic disk, an optical disk, or the like.

[0128] The above-disclosed content is only a preferred embodiment of the present invention, and of course, it cannot be used to limit the scope of the rights of the present invention. Therefore, equivalent changes made according to the claims of the present invention still fall within the scope covered by the present invention.

Claims

1. A stacking picking and releasing control method, characterized in that: include: During the process of picking up or putting down goods, before the fork is extended to the right position, the lifting motor brake is opened. During the process of extending the fork to pick up goods and retracting the fork, the lifting motor remains in the excitation state and hovers at zero speed; When the lifting motor is running and the cargo platform is being raised or lowered, the fork motor remains braked and is not closed, and is in an excitation state; Among them, when the cargo platform is offset during the process of picking up or putting away goods, the lifting motor pulls the cargo platform to adjust in real time to keep the cargo platform in the set position; When the fork opens the brake and the fork is extended or retracted, the deviation between the cargo platform and the set position is calculated; the lifting motor pulls the cargo platform to the set position in real time. If the deviation of the cargo platform exceeds 5 mm, an alarm is triggered and the operation is stopped.

2. A stacking and picking control method according to claim 1, characterized in that: The pickup process is: Q1: After the horizontal mechanism and the lifting motor are in place, the lifting motor does not close the brake and hovers at zero speed; Q2: The fork motor opens the brake, the fork extends, and after the fork is extended to the right position, the fork motor does not close the brake and hovers at zero speed; Q3: After the fork is extended to the right position, the cargo platform is lifted. After it is lifted to the right position, the lifting motor does not close the brake and hovers at zero speed; Q4: After the cargo platform is slightly lifted into place, the forks are retracted. After the forks are retracted into place, the lifting motor and the fork motor brake are closed.

3. A stacking and picking control method according to claim 2, characterized in that: The process of releasing goods is: F1: The horizontal mechanism and the lifting motor do not close the brakes and hover at zero speed; F2: After the lifting motor is in place, the fork opens the brake and the fork extends. After the fork is extended to the right position, the fork motor does not close the brake and hovers at zero speed; F3: After the fork is extended to the right position, the cargo platform descends. After descending to the right position, the lifting motor does not close the brake and hovers at zero speed; F4: After the cargo platform is lowered into place, the forks are retracted. After the forks are retracted into place, the lifting motor and the fork motor brake are closed.

4. A stacking and picking and releasing control method according to claim 2, characterized in that: During the lifting process of the cargo platform, set the average acceleration a of the lifting u , maximum speed v u , the initial speed and final speed are 0, the running distance from 0 to the maximum speed and from the maximum speed to 0 is The running time from 0 to the maximum speed and from the maximum speed to 0 is The uniform motion time is The minimum distance that the fork is lifted until it touches the bottom surface of the cargo but, like but Distance formula: like According to the distance formula: Calculate the minimum time required to reach the allowable lifting height. If the fork overshoots or moves back within the required minimum time, it is considered safe. If the fork has not reached the set position after exceeding the required minimum time, the movement will stop and an alarm will be issued.

5. A stacking and picking and releasing control method according to claim 3, characterized in that: During the descent of the cargo platform, set the average descent acceleration a d , maximum speed v d , the initial speed and final speed are 0, and the running distance from 0 to the maximum speed and from the maximum speed to 0 is The running time from 0 to the maximum speed and from the maximum speed to 0 is The uniform motion time is The minimum distance that the fork is lifted until it touches the bottom surface of the cargo Minimum time like but Distance formula: like According to the distance formula but, Calculate the minimum time required to reach the allowed descent height. If the fork overshoots or moves back within the required minimum time, it is considered safe. If the fork has not reached the set position after the minimum time, an alarm will be triggered and the operation will stop.

6. A stacker pick-up and release control system, used to implement a stacker pick-up and release control method according to any one of claims 1 to 5, characterized in that: include: Detection unit, detecting the real-time position, speed and acceleration of the cargo platform; The data processing unit calculates the distance deviation between the real-time position of the cargo platform and the set position according to the real-time position of the cargo platform; and calculates the shortest time required for the fork to pick up or put down the cargo according to the operating status of the fork; The control unit, the detection unit, the data processing unit, the fork motor, and the lifting motor are electrically connected to the control unit respectively; The control unit controls the fork motor to run or hover at zero speed through instructions, and the fork motor drives the fork to extend or retract; the control unit controls the lifting motor to run through instructions, pulling and adjusting the cargo platform to remain in the set position; the control unit determines whether the fork runs to the set position within the shortest time required for the fork to pick up or put down the goods. When the fork does not reach the set position, an alarm is issued, and the fork motor and lifting motor are controlled to stop running.

7. An electronic device, characterized in that: The device includes a processor and a memory, wherein the memory stores at least one instruction or at least one program, and the at least one instruction or at least one program is loaded and executed by the processor to implement a stacking picking and releasing control method as described in any one of claims 1-5.

8. A computer-readable storage medium, characterized in that: The storage medium stores at least one instruction or at least one program, and the at least one instruction or the at least one program is loaded and executed by the processor to implement a stacking picking and releasing control method as described in any one of claims 1-5.

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