JP2007197134A - Method for controlling stacker crane and controller for stacker crane - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for controlling a stacker crane and a controller for the stacker crane for facilitating control handling and suppressing the deviation of the completion of traveling operation and elevating and operation of a load-carrying platform. <P>SOLUTION: This crane controller accelerates the traveling speed Vx of the load-carrying platform by acceleration α at S100 during the traveling operation of the load-carrying platform. Elevating and lowering speed Vy is calculated by multiplying a ratio of a traveling distance dx required from a current position of the load-carrying platform to a target position of the load-carrying platform to an elevating and lowering distance dy required from the current position of the load-carrying platform to the target position of the load-carrying platform by the traveling speed Vx at S101 to drive and control the load-carrying platform based on the results of calculation. When the required traveling distance dx is reduced below a deceleration start distance Td set by a distance from the target position of the load-carrying platform, the deceleration of the load-carrying platform is started. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a control method and a control apparatus for a stacker crane that carries in and out a load in an automatic warehouse.

  In the conventional control method of the stacker crane, in order to make the cargo bed reach the destination quickly, control is performed to accelerate the two axes of traveling and lifting up to the maximum speed. In the conventional stacker crane control method that performs such control, either the traveling operation or the lifting operation is completed depending on the position of the loading platform, but either one is still operating. was there. Therefore, in the conventional stacker crane control method, the moving speed of the loading platform is unnecessarily accelerated as much as either the traveling operation or the lifting operation is completed first, and the power consumption is increased accordingly.

  Therefore, conventionally, a stacker crane control method has been proposed in which the traveling operation and lifting operation of the loading platform are completed simultaneously as much as possible without reducing the speed of loading and unloading. As a control method of such a stacker crane, for example, a control method of a stacker crane that controls the operation of the stacker crane based on a required travel distance and a required lift distance from the current position to the target position (see Patent Document 1), There is a stacker crane control method (see Patent Document 2) that controls the operation of the stacker crane based on the time required for traveling the loading platform and the time required for lifting the loading platform.

  In the operation control method of the stacker crane of Patent Document 1, the required traveling distance and the required lifting distance are calculated and compared, and the traveling speed corresponding to the longer distance of the traveling speed and lifting speed of the loading platform is maximized. To do. And the movement speed of the shorter distance is controlled to be lower as the difference or ratio between the required travel distance and the required lifting distance is larger, so that the operation with the shorter distance is prevented from being completed first. To do.

In the stacker crane control method described in Patent Document 2, first, the time required for traveling when operating at the highest speed and the time required for moving up and down when operated at the highest speed are described. A size comparison is made before the movement of the loading platform starts. When the traveling time is longer than the ascending / descending time, the traveling speed is set to the fastest pattern, and the ascending / descending speed is determined by reading the ascending / descending speed pattern of a suitable carrier from the ascending / descending speed pattern table. When the raising / lowering time is longer than the traveling time, the ascending / descending speed is set to the fastest pattern, and the traveling speed is determined by reading a suitable traveling speed pattern of the carrier from the traveling speed pattern table. In the stacker crane control method described in Patent Document 2, the moving speed of the longer required time is set to the highest speed, and the moving speed of the shorter required time is determined by reading the speed pattern from the pattern table. The traveling time of the loading platform and the lifting time of the loading platform are made the same as much as possible.
JP-A-6-135508 JP 2004-210454 A

  In the control method of the stacker crane described in Patent Document 1, the required travel distance and the required lift distance are compared and divided into three cases. After the processing set for each case is performed, The moving speed is set. Moreover, in the stacker crane control method described in Patent Document 1, when the required travel distance and the required lift distance are not the same, the distance is obtained by dividing the 16 speed steps by the ratio of the required travel distance and the required lift distance. The moving speed of the loading platform is set by determining the speed stage of the moving speed that is shorter. However, in the stacker crane control method described in Patent Document 1 that performs such control, different processing is set for each of the three cases divided by the size comparison between the required travel distance and the required lift distance. Control for setting the traveling speed of the loading platform and the lifting speed of the loading platform is complicated.

  In the stacker crane control method described in Patent Document 2, a series of processes are performed before the loading platform is operated to determine the moving speed of the loading platform, and then the moving operation of the loading platform is started. If the error occurs between the target speed and the actual platform movement speed, or if slipping occurs when the stacker crane moves (travels), the travel completion time and the lift completion time are calculated before the platform movement operation. And may be different. Therefore, in the stacker crane control method described in Patent Document 2, there is a high possibility that a deviation occurs between the loading completion time of the loading platform and the lifting completion time of the loading platform.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a stacker crane control method that is simple in control process and can suppress the completion of the traveling operation of the loading platform and the completion of the lifting operation of the loading platform. And it is providing the control apparatus of a stacker crane.

  The invention described in claim 1 is a control method for a stacker crane that is equipped with a loading platform on which a load can be placed and that loads and unloads the load, and the traveling speed of the loading platform is changed during the movement of the loading platform. One of the lifting speeds of the loading platform is increased at a predetermined acceleration, and the other speed is increased from the required travel distance from the current position of the loading platform to the target position of the loading platform and the current position of the loading platform. Calculated by multiplying the ratio of the required lifting distance to the target position of the loading platform by one speed, and controlling the traveling and lifting of the loading platform multiple times based on the calculation result, the loading platform starts to decelerate The gist is to start deceleration of the loading platform after reaching the position.

  In this specification, “required travel distance” means a distance in the horizontal direction from the current position of the loading platform to the target position. Further, the “necessary lifting distance” means a distance in the vertical direction from the current position of the loading platform to the target position.

  “Deceleration start position” means a position where deceleration starts while the platform is moving. For example, a horizontal or vertical distance from a target position of the platform to a certain point in the horizontal or vertical direction at a predetermined distance. Set by

  According to this structure, it was calculated by multiplying the ratio of the required travel distance from the current position of the cargo bed to the target position of the cargo bed and the required lifting distance from the current position of the cargo bed to the target position of the cargo bed and one speed. Since the value is set as the other speed, the traveling speed and the ascending / descending speed increase at a constant rate. In addition, since the traveling speed and the lifting speed can be set by performing a process of increasing at a predetermined acceleration and a process of multiplying the distance ratio and the speed, the calculation for setting the moving speed of the loading platform is simplified. Further, since the travel speed and the lifting speed are set a plurality of times during the movement of the cargo bed, an error between the target speed of the cargo bed and the actual movement speed of the cargo bed or the movement of the stacker crane (running) ), Slippage between the loading completion time of the loading platform and the lifting completion time of the loading platform can be suppressed.

  The invention according to claim 2 is the invention according to claim 1, wherein one of the traveling speed of the cargo bed and the lifting speed of the cargo bed is increased at a predetermined acceleration, and the other speed is Calculated by multiplying one speed by the ratio of the required travel distance from the current position of the cargo bed to the target position of the cargo bed and the required lifting distance from the current position of the cargo bed to the target position of the cargo bed, and the calculation result The gist of the present invention is to repeatedly control the traveling and raising / lowering of the loading platform until the loading platform reaches the deceleration start position.

  According to this configuration, the traveling speed of the loading platform and the lifting speed of the loading platform are calculated, and the traveling and lifting of the loading platform are controlled repeatedly until either the necessary traveling distance or the necessary lifting distance reaches the deceleration start distance. Therefore, even if there is an error between the target speed of the loading platform and the actual loading speed of the loading platform or slipping during the movement (traveling) of the stacker crane during the loading platform movement, the loading completion time of the loading platform and the lifting / lowering of the loading platform Deviations from the completion time are avoided.

  The invention according to claim 3 is a control method for a stacker crane that is equipped with a loading platform on which a load can be placed, and that loads and unloads the load, and the traveling speed of the loading platform is changed during the movement of the loading platform. The speed of acceleration of the loading platform is increased at a predetermined acceleration, and the required traveling distance from the current position of the loading platform to the target position of the loading platform, and the required lifting distance from the current position of the loading platform to the target position of the loading platform, The travel speed is calculated by multiplying the travel speed, and the travel speed is compared with a preset maximum travel speed. When the travel speed is equal to or higher than the maximum travel speed, the travel speed is increased. When the travel speed is less than the maximum travel speed, the vertical speed is compared with a preset maximum travel speed. When the travel speed is equal to or higher than the maximum travel speed, the travel speed is Stop acceleration, and when the ascending / descending speed is less than the maximum ascending / descending speed, a series of control for further increasing the traveling speed is repeated until either the traveling distance or the ascending / descending distance becomes smaller than the deceleration start distance. And when either one of the required travel distance or the required lift distance becomes smaller than the deceleration start distance set by the distance from the target position of the cargo bed, the travel speed and the lift speed are decelerated. The gist is to start.

  According to this configuration, when either one of the traveling speed and the ascending / descending speed becomes equal to or higher than the preset maximum speed, the control for stopping the increase in the traveling speed and the ascending / descending speed is performed. Therefore, since it is avoided that the situation where the traveling speed and the lifting speed continue to be increased until the loading platform reaches the deceleration start distance can be avoided, it is possible to suppress the wasteful acceleration of the loading platform and excessive power consumption. .

  According to the invention described in claim 4, a control device for a stacker crane which is equipped with a loading platform on which a load can be placed and which loads and unloads the load, from the current position of the loading platform to a target position. A travel distance detecting means for detecting the required travel distance; a lift distance detecting means for detecting a required lift distance from a current position of the cargo bed to a target position; a running means for the cargo bed; a lift means for the cargo bed; Increase the speed of lifting / lowering the loading platform or the traveling speed of the loading platform at a predetermined acceleration, and multiply the other speed by the ratio of the required traveling distance to the required lifting distance. Control means for controlling the traveling means and the lifting means based on the calculation result, and performing deceleration control of the traveling means and the lifting means after the cargo bed has reached the deceleration start position. , And summarized in that with a.

  According to this configuration, the control means is calculated by multiplying the ratio of the travel distance from the current position of the loading platform to the target position of the loading platform and the lifting distance from the current position of the loading platform to the target position of the loading platform and one speed. In this case, the traveling speed and the ascending / descending speed increase at a constant rate. In addition, since the traveling speed and the lifting speed can be set by performing a process of increasing at a predetermined acceleration and a process of multiplying the distance ratio and the speed, the calculation for setting the moving speed of the loading platform is simplified. Further, since the control means sets the traveling speed and the lifting speed a plurality of times during the movement of the cargo bed, the error between the target speed of the cargo bed and the actual movement speed of the cargo bed during the movement of the cargo bed or the stacker crane Even if slippage occurs during movement (traveling), it is possible to suppress a difference between the traveling completion time of the loading platform and the lifting completion time of the loading platform.

  According to the present invention, it is possible to simplify the control process and to prevent the completion of the traveling operation of the loading platform and the completion of the lifting operation of the loading platform.

Hereinafter, an embodiment embodying the present invention will be described with reference to FIGS.
As shown in FIG. 1, the automatic warehouse 1 includes a load receiving stand 2 installed on a floor surface, and a stacker crane 4 as a transporter for transferring loads between the shelf 3 and the load receiving stand 2. . The cargo receiving platform 2 is provided on the end side of the shelf 3 and includes an incoming cargo receiving platform 2a as an incoming port and an outgoing cargo receiving platform 2b as an outgoing port. The shelf 3 is erected on the floor surface and includes a plurality of storage portions 3a that are connected in the depth direction (traveling direction of the stacker crane) and the height direction.

  The stacker crane 4 can be moved up and down between the mast 12, a rail 10 laid on the floor, a traveling platform 11 traveling on the rail 10, a pair of masts 12 erected from both ends of the traveling platform 11, and the mast 12. The loading platform 13 is provided.

  The loading platform 13 is provided with a fork 14 that can push out loads to the shelves 3 and draw loads from the shelves 3 to the mast 12. The mast 12 is provided with a crane control device 20.

  The crane control device 20 can communicate with a main control device 21 installed at a position away from the shelf 3. The crane control device 20 performs control to move the loading platform 13 between the loading platform 2 and the storage unit 3a by running the traveling platform 11 and raising and lowering the loading platform 13. Moreover, the crane control apparatus 20 performs control which moves a load between the accommodating part 3a and the loading platform 13, and between the loading platform 13 and the loading platform 2 by operating the fork 14. FIG.

  The crane control device 20 includes a memory, and the memory includes a maximum traveling speed Vxmax that is an upper limit value of the loading platform 13, a maximum lifting speed Vymax that is an upper limit value of the lifting platform 13, and an increase rate of the traveling speed. And the deceleration start distance Td used when determining whether or not the platform has reached the deceleration start position (deceleration point). In this embodiment, the maximum traveling speed Vxmax is set higher than the maximum ascending / descending speed Vymax. For example, the maximum traveling speed Vxmax is set to about 80 [m / min], and the maximum lifting speed Vymax is set to about 20 [m / min] when no load is placed. When it is mounted, it is set to about 10 [m / min].

  As shown in FIG. 2, the main controller 21 is provided with a laser distance measuring device 22. The laser distance measuring device 22 includes a light emitting unit 23 that emits an infrared laser, and the light emitting unit 23 faces a reflecting mirror 24 embedded in a cover portion of the crane control device 20. The travel distance detecting means for detecting the travel distance of the loading platform 13 includes a laser distance measuring device 22 and a reflecting mirror 24.

  As shown in FIG. 2, a pulley 15 is provided on the top of the mast 12, and a chain 16 is hung on the pulley 15. In the mast 12, a measuring wheel 17 that is rolled by the movement of the chain 16 is provided. An encoder (not shown) is connected to the measuring wheel 17. The encoder outputs a pulse signal proportional to the amount of rotation of the measuring wheel 17. A pulse signal proportional to the rotation amount of the measuring wheel 17 is input to the crane control device 20. The crane control device 20 calculates the lift distance of the loading platform 13 from the input pulse signal. The elevating distance detecting means includes the measuring wheel 17, an encoder (not shown), and the crane control device 20.

  Further, the main control device 21 inputs information such as the name of the goods via the keyboard by the operator, and the storage unit 3a and the storage of the delivery source for loading and unloading the load from one storage unit 3a to the other storage unit 3a. Operation means capable of specifying the previous storage portion 3a is provided. The memory of the main controller 21 stores the position information of each storage unit 3a, position information, etc., the load form information of the load that can be stored in each storage unit 3a (allowable load form), and the storage unit 3a. Information (for example, product name, product number, quantity, storage location, etc.) of each package is stored.

  Furthermore, a host controller (not shown) that can communicate with the main controller 21 is also provided. The host controller is a device that manages the entire automatic warehouse 1, stores information on all automatic warehouses (not shown) including the automatic warehouse 1, information on all loads, etc., and manages all automatic warehouses. .

  The crane control device 20 as the control means moves the platform 11 by a motor (not shown) to move the platform 13 in the horizontal direction and moves the chain 16 by a motor (not shown) to move the platform 13 in the vertical direction. The loading platform 13 is moved. Therefore, the traveling means is constituted by a traveling table 11 and a motor (not shown) that causes the traveling table 11 to travel. The elevating means includes a chain 16 and a motor (not shown) that moves the chain 16.

Next, the operation of the stacker crane control apparatus configured as described above will be described.
When an operator selects an operation start mode of the stacker crane 4 after designating a cargo unloading source and a cargo receiving destination from operating means provided in the main control device 21, the main control device 21 selects the crane control device. The operation command signal of the stacker crane 4 is output to 20. When the crane control device 20 receives the operation command signal, the crane control device 20 starts the operation of the stacker crane 4.

  When unloading the load stored in the storage unit 3a, as shown in FIG. 3, the stacker crane 4 serves as a target position for unloading the load from a position facing the storage unit 3a that is the starting position. The loading platform 13 is moved to a position facing the delivery cargo receiving platform 2b. And while the loading platform 13 moves from the storage unit 3a of the shipping source to the shipping receiving platform 2b, the laser distance measuring device 22 reflects the infrared laser emitted from the light emitting portion 23 by the reflecting mirror and then returns to the laser distance measuring device 22. The time required to return is measured, and the required travel distance dx from the current position of the loading platform to the target position is always detected (calculated). The detection result of the required travel distance dx detected by the laser distance measuring device 22 is output to the crane control device 20. In addition, a pulse signal is output from the encoder as the measuring wheel 17 rotates, and the crane control device 20 calculates the pulse signal so that the crane control device 20 has the necessary lifting distance dy from the current position of the loading platform to the target position. Is always detected (calculated).

The crane control device 20 performs the processing shown in FIG. 4 until the loading platform 13 reaches the target position from the starting position.
First, in step (hereinafter referred to as “S”) 100, the traveling means is controlled so as to increase the traveling speed Vx of the traveling platform 11 by a predetermined acceleration α. Next, in S101, it is determined whether or not the loading platform 13 has reached the deceleration point. The determination as to whether or not the loading platform 13 has reached the deceleration point is based on whether or not the required travel distance dx from the current position of the loading platform 13 to the target position is equal to or less than the deceleration start distance Td set by the distance from the target position. It is done by judging.

When it is determined that the loading platform 13 has reached the deceleration point, that is, when it is determined that the required travel distance dx is equal to or less than the deceleration start distance Td, the routine proceeds to the deceleration routine of S200.
When the loading platform 13 has not reached the deceleration point, the lifting speed Vy of the loading platform 13 is calculated in S102 by multiplying the ratio of the required traveling distance dx and the required lifting distance dy by the traveling speed Vx. The elevating means is controlled so that the speed Vy becomes the calculated value. After calculating the ascending / descending speed Vy, the magnitude comparison between the traveling speed Vx and the preset maximum traveling speed Vxmax is performed in S103. If it is determined in S103 that the traveling speed Vx is equal to or higher than the maximum traveling speed Vxmax, the acceleration of the traveling speed Vx is stopped in S104, and the traveling speed Vx is decelerated by the acceleration α. Thereafter, the process proceeds to S101.

  If it is determined in S103 that the traveling speed Vx is lower than the maximum traveling speed Vxmax, the process proceeds to S105. In S105, the vertical speed Vy is compared with a preset maximum vertical speed Vymax. If it is determined in S105 that the ascending / descending speed Vy is equal to or higher than the maximum ascending / descending speed Vymax, in S106, the acceleration of the traveling speed Vx is stopped and the traveling speed Vx is decelerated by the acceleration α. Thereafter, the process proceeds to S101.

  If it is determined in S105 that the ascending / descending speed Vy is smaller than the maximum ascending / descending speed Vymax, the traveling speed Vx is increased by the acceleration α in S107, and the process proceeds to S101 again. That is, the crane control device 20 repeats the processing from S101 to S107 until the loading platform 13 reaches the deceleration point, and when it is determined that the required travel distance dx is smaller than the deceleration start distance Td, the crane control device 20 proceeds to the deceleration routine. .

  In the deceleration routine, the traveling speed Vx of the loading platform 13 and the raising / lowering speed Vy of the loading platform 13 are decelerated at the same rate as the traveling speed Vx of the loading platform 13 and the raising / lowering speed Vy of the loading platform 13 performed by the processing of S101 to S107. Take control. The traveling operation of the loading platform 13 and the lifting / lowering operation of the loading platform 13 are completed simultaneously when the loading platform 13 arrives at the target position.

  Next, when the stacker crane 4 is controlled by the crane control device 20, the transition of the traveling speed Vx of the loading platform 13 and the lifting speed Vy of the loading platform 13 until the loading platform 13 reaches the target position from the starting position will be described. To do.

When the lifting / lowering speed of the loading platform 13 reaches the maximum lifting / lowering speed before the loading platform 13 reaches the target position from the starting position, the traveling speed Vx and the lifting / lowering speed Vy change as shown in FIG.
First, the ascending / descending speed Vy increases at a constant rate, and is maintained constant when the maximum ascending / descending speed Vymax is reached. The traveling speed Vx increases by the acceleration α, and when the ascending / descending speed Vy reaches the maximum ascending / descending speed Vymax, the traveling speed Vx does not increase and is maintained at a constant speed. At this time, the traveling speed Vx does not reach the maximum traveling speed Vxmax.

  When the loading platform 13 reaches the deceleration point, deceleration of the traveling speed Vx and the lifting speed Vy is started. At this time, the traveling speed Vx is decelerated at the same rate as the increasing ratio of the traveling speed Vx. Similarly, the deceleration of the ascending / descending speed Vy is performed at the same rate as the increasing rate of the ascending / descending speed Vy.

  When the traveling speed Vx of the loading platform 13 reaches the maximum traveling speed Vxmax before the platform 13 reaches the target position, the traveling speed Vx and the lifting speed Vy change as shown in FIG.

  First, the traveling speed Vx is increased by the acceleration α, and is maintained constant when the traveling speed Vxmax is reached. The ascending / descending speed Vy increases at a constant rate, and when the traveling speed Vx reaches the maximum traveling speed Vxmax, the increase / decrease in the ascending / descending speed Vy stops and is maintained at a constant speed. At this time, the lifting speed Vy does not reach the maximum lifting speed Vymax. When the loading platform 13 reaches the deceleration point, the traveling speed Vx and the lifting / lowering speed Vy are decelerated in the same manner as when the lifting / lowering speed of the loading platform 13 reaches the maximum lifting / lowering speed Vymax.

  In addition, when the distance from the starting position to the target position is short, the loading platform 13 may reach a deceleration point before the traveling speed Vx of the loading platform 13 and the lifting speed Vy of the loading platform 13 reach the maximum speed. At this time, the traveling speed Vx of the loading platform 13 and the lifting speed Vy of the loading platform 13 change as shown in FIG.

  First, the traveling speed Vx of the loading platform 13 and the lifting speed Vy of the loading platform 13 are increased at a constant rate. Thereafter, when the loading platform 13 reaches the deceleration point, deceleration of the traveling velocity Vx of the loading platform 13 and the lifting velocity Vy of the loading platform 13 is started, and when the loading platform 13 reaches the target position, the traveling velocity Vx and the lifting velocity Vy are 0. become.

The above control is a control in the case where traveling and raising / lowering are performed before the loading platform 13 reaches the target position from the starting position.
Next, when the load is moved from the departure position to the destination position, the storage unit 3a of the warehousing source and the storage unit 3a of the warehousing destination are on the same stage, and the storage unit 3a of the warehousing source and the warehousing destination The operation of the stacker crane when the storage unit 3a is in the same series will be described.

  When the storage unit 3a of the warehousing source and the storage unit 3a of the warehousing destination are on the same level, the crane control device 20 performs only the traveling operation of the loading platform 13 because the required lifting distance dy is 0 from the control start time. At this time, the crane control device 20 accelerates the loading platform 13 without performing the processes of S101 to S107, and then decelerates and moves it to the storage destination.

  In addition, when the storage unit 3a as the warehousing source and the storage unit 3a as the warehousing destination are the same, the required travel distance dx is 0 from the control start time, so the crane control device 20 performs only the lifting and lowering operation of the loading platform 13. . At this time, the crane control device 20 accelerates the loading platform 13 without performing the processes of S101 to S107, and then decelerates and moves it to the storage destination.

This embodiment has the following effects.
(1) The crane control device 20 increases the traveling speed Vx of the loading platform 13 at a predetermined acceleration α, and the traveling speed Vy of the loading platform 13 is increased with respect to the ratio of the necessary traveling distance dx and the necessary lifting distance dy. Calculated by multiplying by Vx.

  Since the traveling speed Vx and the lifting speed Vy are set based on the ratio between the required traveling distance dx and the required lifting distance dy, the traveling speed Vx and the lifting speed Vy do not increase unnecessarily. Further, the traveling speed Vx can be set by the process of S101 for increasing the acceleration by a predetermined acceleration α, and the ascending / descending speed Vy can be set by the process of S102 by multiplying the ratio of the necessary traveling distance dx and the necessary lifting distance dy by the traveling speed Vx. Since it can set, the control which sets the traveling speed Vx of the loading platform 13 and the raising / lowering speed Vy of the loading platform 13 does not become complicated.

  Furthermore, since the traveling speed Vx and the lifting speed Vy are set while the cargo bed 13 is moving, an error between the target speed of the cargo bed 13 and the actual moving speed of the cargo bed 13 during the movement of the cargo bed 13 or the stacker crane 4 Even if slippage occurs during the movement (traveling), the difference between the traveling completion time of the loading platform 13 and the lifting completion time of the loading platform 13 can be suppressed.

  (2) When it is determined that the required travel distance dx is equal to or less than the deceleration start distance Td set by the distance from the target position of the loading platform 13, the crane control device 20 determines that the deceleration start position has been reached and determines in S200. Transition to deceleration routine.

  If the deceleration start position is set to the deceleration start distance Td that is a distance from the target position, the deceleration start position is not affected by the distance from the departure position to the target position. Therefore, the deceleration start position of the cargo bed 13 can be set only by setting one deceleration start distance Td in advance.

  (3) The crane control device 20 repeatedly performs the processing from S101 to S107 until the loading platform 13 reaches the deceleration point. When it is determined that the required travel distance dx is smaller than the deceleration start distance Td, the crane control device 20 proceeds to the deceleration routine.

  Since S101 and S102, which are processes for setting the traveling speed Vx of the loading platform 13 and the raising / lowering speed Vy of the loading platform 13, are repeatedly performed until the required traveling distance dx reaches the deceleration start distance Td, the loading platform 13 moves while the loading platform 13 is moving. Even if an error occurs between the target speed and the actual moving speed of the loading platform 13 or a slip occurs when the stacker crane 4 moves (runs), there is a difference between the traveling completion time of the loading platform 13 and the lifting completion time of the loading platform 13. This is avoided.

  (4) When the traveling speed Vx is determined to be equal to or higher than the maximum traveling speed Vxmax, the crane control device 20 stops increasing the traveling speed Vx. Further, when it is determined that the lifting speed Vy is equal to or higher than the maximum lifting speed Vymax, the increase in the traveling speed Vx is stopped.

  That is, the crane control device 20 performs control to stop the increase in the traveling speed Vx and the lifting speed Vy when either the traveling speed Vx or the lifting speed Vy is equal to or higher than a preset maximum speed. Yes. Therefore, it is avoided that the traveling speed Vx and the lifting speed Vy of the loading platform 13 are continuously increased until the deceleration start distance Td is reached, so that the loading platform 13 is unnecessarily accelerated and excessive power is consumed. Can be suppressed.

The embodiment is not limited to the above, and may be embodied as follows, for example.
The crane control device 20 may set the traveling speed Vx based on the lifting speed Vy instead of setting the lifting speed Vy based on the traveling speed Vx. In this case, the crane control device 20 may perform a process of calculating the traveling speed Vx by multiplying the ratio of the required traveling distance dx and the required lifting distance dy by the lifting speed Vy in S102.

  The deceleration of the loading platform 13 does not have to be started when the required travel distance dx becomes equal to or less than the deceleration start distance Td set by the distance from the target position of the loading platform 13. For example, you may set so that deceleration of the loading platform 13 may be started when the required lifting distance dy becomes equal to or less than the deceleration start distance Td set by the distance from the target position of the loading platform 13.

  The deceleration start position of the loading platform 13 may not be set when the required travel distance dx or the required lift distance dy is equal to or less than the deceleration start distance Td. For example, a display unit that indicates the deceleration start position is provided corresponding to each storage unit 3a, and a detection unit that detects the display unit described above is provided on the stacker crane 4. The position where the display unit corresponding to the target position is detected may be set as the deceleration start position.

  Further, a position away from the departure position by a predetermined distance may be set as the deceleration start distance. In this case, in order to set a suitable deceleration start position for each distance from the starting position to the target position, a deceleration starting distance corresponding to the distance from the starting position to the target position is set, and the set deceleration starting distance is set respectively. You may memorize | store in the memory of the crane control apparatus 20. FIG. In this case, the crane control device 20 reads the deceleration start distance corresponding to the distance from the starting position designated by the operator to the target position when controlling the stacker crane 4. And the crane control apparatus 20 is controlled so that the deceleration of the loading platform 13 is started when the required travel distance dx of the loading platform 13 or the necessary lifting distance dy becomes equal to or greater than the deceleration start distance during the movement of the loading platform 13.

O The processing from S101 to S107 may be performed a plurality of times. For example, the crane control device 20 may be controlled so that the processes from S101 to S107 are performed at intervals of 0.5 seconds.
The maximum traveling speed Vxmax need not be set higher than the maximum lifting speed Vymax. That is, the maximum lifting speed Vymax may be set to be greater than the maximum traveling speed Vxmax.

  O The laser distance measuring device 22 may not be used as the travel distance detecting means. For example, if a measuring wheel that rolls on the traveling surface of the traveling rail 10 is provided and an encoder is connected to the measuring wheel, the encoder outputs a pulse signal proportional to the amount of rotation of the measuring wheel. The control device 20 can calculate the travel distance of the loading platform 13.

  The measuring wheel 17, the encoder, and the crane control device 20 do not have to be used as the lifting distance detection means. For example, a laser distance measuring device and a reflecting mirror may be used as the lifting distance detecting means. In this case, a laser distance measuring device is provided on the inner side surface of the mast 12, and the laser distance measuring device is disposed so as to be positioned below the mast 12. Then, if a reflecting mirror is provided on the lower surface of the loading platform 13 so as to face the light emitting part of the laser distance measuring device, the laser light emitted from the laser distance measuring device is reflected by the reflecting mirror and is suitably applied to the laser distance measuring device. Since it returns, the raising / lowering distance of the loading platform 13 can be detected by using the time from when the laser beam is emitted until it returns.

  ○ When it is determined that the traveling speed Vx is greater than the maximum traveling speed Vxmax and when it is determined that the ascending / descending speed Vy is greater than the maximum ascending / descending speed Vymax, the traveling speed Vx is decelerated by the acceleration α in S104 and S106. However, the deceleration amount may be smaller than the acceleration α. For example, the traveling speed Vx may be decelerated by the acceleration α / 2 in S104 and S106, or the traveling speed Vx may not be decelerated in S104 and S106.

The following technical idea can be understood from the embodiment.
(1) In the invention according to claim 2, when either the traveling speed or the ascending / descending speed is equal to or higher than a preset maximum speed, the increase in the traveling speed and the ascending / descending speed is stopped. Stacker crane control method.

The perspective view of the automatic warehouse provided with the stacker crane. A schematic side view of an automatic warehouse equipped with a stacker crane. The schematic diagram explaining operation | movement of a loading platform. The flowchart which shows the traveling and raising / lowering control of a loading platform which a crane control apparatus performs. (A) The graph which shows transition of the traveling speed and raising / lowering speed of a loading platform in case the raising / lowering speed of a loading platform reaches the maximum raising / lowering speed during the movement operation of a loading platform. (B) The graph which shows transition of the traveling speed and raising / lowering speed of a loading platform in case the traveling speed of a loading platform reaches the maximum traveling speed during the movement operation of a loading platform. (C) The graph which shows transition of the traveling speed and raising / lowering speed of a loading platform in case a loading platform reaches a deceleration point before traveling speed and raising / lowering speed reach the maximum speed.

Explanation of symbols

  α: acceleration, dx: required travel distance, dy: necessary lift distance, Td: deceleration start distance, Vx: travel speed, Vy: lift speed, Vxmax: maximum travel speed, Vymax: maximum lift speed, 4: stacker crane, 13 DESCRIPTION OF SYMBOLS ... Loading platform, 16 ... Chain, 17 ... Measuring wheel, 20 ... Crane control apparatus, 22 ... Laser distance measuring device, 23 ... Light emission part, 24 ... Reflector.

Claims (4)

A stacker crane control method for loading and unloading a load while equipped with a loading platform on which a load can be placed,
During the movement of the loading platform, one of the traveling speed of the loading platform and the lifting speed of the loading platform is increased at a predetermined acceleration, and the other speed is increased from the current position of the loading platform to the purpose of the loading platform. Calculate by multiplying one speed by the ratio of the required travel distance to the position and the required lift distance from the current position of the cargo bed to the target position of the cargo bed, and based on the calculation results A control method for a stacker crane that performs control a plurality of times and starts deceleration of the cargo bed after the cargo bed reaches a deceleration start position. Either one of the traveling speed of the loading platform and the lifting speed of the loading platform is increased at a predetermined acceleration, and the other speed is calculated based on the necessary traveling distance from the current position of the loading platform to the target position of the loading platform, Calculated by multiplying one speed by the ratio of the required lifting distance from the current position of the loading platform to the target position of the loading platform, and the loading platform decelerates controlling the traveling and lifting of the loading platform based on the calculation result The stacker crane control method according to claim 1, wherein the stacker crane is repeatedly performed until the start position is reached. A stacker crane control method for loading and unloading a load while equipped with a loading platform on which a load can be placed,
While moving the loading platform, the traveling speed of the loading platform is increased at a predetermined acceleration, and the ascending / descending speed of the loading platform is set to a required traveling distance from the current position of the loading platform to the target position of the loading platform and Calculate by multiplying the traveling speed by the ratio of the required lifting distance from the position to the target position of the loading platform,
Comparing the travel speed with a preset maximum travel speed, and when the travel speed is equal to or greater than the maximum travel speed, stop increasing the travel speed,
When the traveling speed is less than the maximum traveling speed, the elevation speed is compared with a preset maximum lifting speed. When the traveling speed is equal to or higher than the maximum lifting speed, the increase in the traveling speed is stopped. And
When the ascending / descending speed is less than the maximum ascending / descending speed, a series of controls for further increasing the traveling speed are repeated until either the traveling distance or the ascending / descending distance becomes smaller than the deceleration start distance,
When either the required travel distance or the required lift distance becomes smaller than the deceleration start distance set by the distance from the target position of the cargo bed, the travel speed and the lift speed are started to be reduced. Stacker crane control method. A stacker crane control device that is equipped with a loading platform on which a load can be placed, and that loads and unloads a load,
Travel distance detection means for detecting a required travel distance from the current position of the cargo bed to the target position;
Lifting distance detecting means for detecting a required lifting distance from the current position of the cargo bed to the target position;
Traveling means of the loading platform;
Elevating means for the cargo bed;
Either the lifting speed of the loading platform or the traveling speed of the loading platform is increased at a predetermined acceleration, and the other speed is multiplied by the ratio of the required traveling distance and the required lifting distance to one speed. Control means for controlling the traveling means and the lifting means based on the calculation result, and performing deceleration control of the traveling means and the lifting means after the cargo bed has reached the deceleration start position;
A control apparatus for a stacker crane, comprising:

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