JP5572104B2 - Mobile system - Google Patents

Description

  The present invention relates to a mobile system, and more particularly to a mobile system in which a plurality of mobile bodies can move within a plane range.

  A conventional automatic warehouse includes, for example, a pair of racks, a stacker crane, a warehouse station, and a warehouse station. The pair of racks are provided at a predetermined interval in the front-rear direction. The stacker crane is provided so as to be movable in the left-right direction between the front and rear racks. The warehousing station is arranged on the side of one rack. The delivery station is arranged on the side of the other rack. The rack has a large number of article storage shelves arranged vertically and horizontally. The stacker crane has a traveling carriage, a lifting platform that can be raised and lowered by a mast provided therein, and an article transfer device (for example, a slide fork that is slidable in the front-rear direction). doing. In the loading / unloading station, a conveyor is used to transport the articles.

  In recent years, in order to improve the efficiency of the article storage work, an automatic warehouse has been proposed in which, for example, two stacker cranes can pass between the front and rear racks. This automatic warehouse has a pair of racks and two stacker cranes that can run in parallel between them. The article transfer device of the stacker crane can carry in and out goods for both the front and rear racks.

  When this automatic warehouse is viewed from the side, each set of two stacker crane elevators and article transfer devices (hereinafter referred to as “transfer section”) interferes with each other in a two-dimensional plane. It can be recognized as two moving bodies that move in a state where there is a possibility of being. These two moving bodies can freely move in a plane by a combination of the traveling operation of the traveling vehicle and the lifting operation of the lifting device. Therefore, in order to prevent interference between the two moving bodies, it is necessary to appropriately control the movement of the moving body.

  In general, a technique for preventing interference between a plurality of moving bodies is required not only in an automatic warehouse but also in a transport vehicle system. For example, in the transport vehicle system described in Patent Document 1, the transport vehicle transmits the current position to the network at predetermined time intervals, intercepts the positions of other transport vehicles, and positions after a predetermined time based on the speed. Is estimated and fed back to the traveling speed of the aircraft. In addition, at the branching section and the merging section, the transport vehicle uses a route map in which two bifurcated traveling routes after branching and before merging are overlapped. As a result, the transport vehicle can travel autonomously, and there is no need to enter a travel permission waiting state at the branching part or the joining part.

JP 2005-301364 A

  Generally, in order to prevent the interference of a plurality of moving bodies, it is necessary to perform a route search process for a plurality of moving bodies. End up.

  An object of the present invention is to reduce the amount of calculation when determining interference of a moving body before starting movement in a moving body system having a first moving body and a second moving body that are movably arranged in a plane. It is in.

  Hereinafter, a plurality of modes will be described as means for solving the problems. These aspects can be arbitrarily combined as necessary.

A mobile system according to an aspect of the present invention includes a first mobile body, a second mobile body, and a control unit. The first moving body and the second moving body are arranged so as to be movable in a plane. The control unit confirms interference between the first moving body and the second moving body on the planned moving path of the first moving body before the first moving body starts moving. The control unit includes a step dividing unit, a step calculating unit, and an interference determining unit. The step dividing unit divides the time or distance in the planned travel route into a plurality of steps. The step calculation unit calculates a step where there is no possibility of interference by considering the mutual distance, moving direction, and speed of the first moving body and the second moving body. The interference determination unit determines the presence or absence of interference by calculating the positions of the first mobile body and the second mobile body, and the first mobile body and the second mobile body for the steps where there is no possibility of interference. The position calculation of is omitted. Further, the step calculation unit uses the maximum speed specification value as the speed.
In this mobile system, first, the time or distance in the planned movement path of the first mobile body is divided into a plurality of steps, and then a step where there is no possibility of interference is calculated. For steps where there is no possibility of interference, the position calculation of the first moving body and the second moving body is omitted. Therefore, the amount of calculation when determining the interference of the moving body before the start of movement is reduced. As a result, the mobile system described above can be implemented in embedded control using a general-purpose board that does not have abundant computer resources.
In this mobile system, the maximum speed specification value is used as the speed value for the calculation, so that the processing load can be further reduced.

The step calculation unit calculates a step that may cause interference by considering the mutual distance, moving direction, and speed of the first moving body and the second moving body, and further from the step that may cause interference. The previous step may be selected as a step that is unlikely to cause interference.
In this mobile system, first, the time or distance in the planned movement path of the first mobile body is divided into a plurality of steps, and then a step that may cause interference is calculated. For the steps before the step with the possibility of interference, the position calculation of the first moving body and the second moving body is omitted. Therefore, the amount of calculation when determining the interference of the moving body before the start of movement is reduced. As a result, the mobile system described above can be implemented in embedded control using a general-purpose board that does not have abundant computer resources.

When the first moving body or the second moving body is stopped, the step calculation unit may employ a condition that acceleration is started immediately from the stopped state.
In this moving body system, since the condition that acceleration is started immediately after the first moving body and the second moving body are stopped is adopted, the values of steps other than the step without interference can be set small. Therefore, it is possible to reliably select a step that may cause interference.

The control unit may further include a grasping unit that grasps a step in which the operation of the second moving body is completed. In that case, the step calculation unit not only before the step of completing the operation of the second moving body, but also the mutual distance and the moving direction of the first moving body and the second moving body in the step of completing the operation of the second moving body. Considering the speed, a step where interference may occur is calculated after the step of completing the operation of the second moving body.
In this mobile body system, if the step of completing the operation of the second mobile body is grasped, a step that may cause interference is calculated after the step of completing the operation of the second mobile body. The reason for this is that it is expected that the path of the second moving body will change greatly when the operation of the second moving body is completed, so that interference may occur after the step of completing the operation of the second moving body. This is because it is preferable to calculate a step having a characteristic.

The control unit may further include a standby position setting unit. In this case, if it is determined that the first moving body and the second moving body interfere with each other at the target position, the standby position setting unit sets a position that causes the first moving body to stand by at a predetermined distance from the target position. To do. Here, “standby” means stopping at any position and not performing the next movement until interference is avoided.
In this mobile body system, if it is determined that the first mobile body and the second mobile body interfere with each other at the target position, the first mobile body is put on standby at a position away from the target position by a predetermined distance. Therefore, this eliminates the need for complicated trajectory calculations necessary to avoid interference when interference occurs at the target position.

The control unit may further include a comparison unit. In this case, if it is determined that the first moving body and the second moving body interfere with each other at the target position, the comparison unit compares the moving time or the moving distance between the first moving body and the second moving body. The standby position setting unit sets the stop position of the first moving body to a position away from the target position by a predetermined distance if the moving time or moving distance of the first moving body is longer than the moving time or moving distance of the second moving body, If the moving time or moving distance of the first moving body is shorter than the moving time or moving distance of the second moving body, the standby position of the first moving body is set to the current position.
In this moving body system, when the first moving body cannot reach the target position earlier than the second moving body, it is moved to a position away from the target position by a predetermined distance and stopped. Therefore, even if it is necessary to perform an avoidance operation when the first moving body subsequently moves to the target position, the amount of time or distance for avoidance can be reduced. On the other hand, when the target position can be reached earlier than the second moving body, the first moving body is made to wait at the current position. Thereby, it is not necessary to perform complicated trajectory calculation when the transfer units interfere with each other at the target position.

The control unit may further include a trajectory calculation unit, a time limit management unit, a repeated execution unit, and a trajectory selection unit. The trajectory calculation unit calculates a trajectory in which the first moving body and the second moving body do not interfere with each other. The time limit management unit manages the time limit for trajectory calculation. The repetitive execution unit causes the trajectory calculation unit to repeatedly execute the trajectory calculation within the time limit. The trajectory selection unit selects an optimal trajectory from a plurality of trajectories calculated by the trajectory calculation unit.
In this moving body system, the trajectory where the first moving body and the second moving body do not interfere is calculated many times within the time limit. An optimal trajectory is selected from a plurality of trajectories. Therefore, a track with high operating efficiency can be selected.

  In the mobile body system according to the present invention, the calculation of the positions of a plurality of mobile bodies for steps that do not interfere is omitted, so that the amount of calculation when determining the interference of the mobile body before the start of movement is reduced.

1 is a schematic plan view of an automatic warehouse in which a first embodiment of the present invention is adopted. It is II arrow directional view of FIG. 1, and is a figure for demonstrating a rack and a stacker crane. It is a partially omitted side view of the automatic warehouse, and is a diagram for explaining a rack and a stacker crane. The functional block diagram which shows the automatic warehouse control structure as 1st Example. The functional block diagram which shows the automatic warehouse control structure as 2nd Example. The functional block diagram of the control part of a stacker crane. The functional block diagram of a main controller. The flowchart which shows the track | orbit determination process by a main controller. The flowchart which shows the interference determination process of a main controller. The flowchart which shows the track | orbit selection process of a main controller. The schematic diagram which shows the some track | orbit between a starting position and a target position. FIG. 3 is a schematic diagram showing two trajectories between a starting position and a target position. The schematic diagram for demonstrating the method in which one transfer part drive | works a detour path | route, when transfer parts may interfere. The schematic diagram for demonstrating the method of delaying the driving | running | working start timing of one transfer part, when transfer parts may interfere. The flowchart which shows the process which determines the optimal value by a bisection method. The schematic diagram which shows the process which determines the via | route position distant from the driving planned track. The schematic diagram which shows the process which determines the via | route position distant from the driving planned track. The schematic diagram which shows the selection judgment of the detour track | orbit which passes along a via position. Time axis from 0 with interference to t _max without interference. The schematic diagram which shows standby operation | movement when two transfer parts interfere in a target position. The functional block diagram of the main controller in 2nd Embodiment. The flowchart which shows the track | orbit determination process of the main controller in 2nd Embodiment.

(1) Whole automatic warehouse The automatic warehouse 1 as 1st Embodiment of this invention is demonstrated using FIGS. 1-3. FIG. 1 is a schematic plan view of an automatic warehouse in which the first embodiment of the present invention is adopted. FIG. 2 is a view taken in the direction of arrow II in FIG. 1 and is a view for explaining a rack and a stacker crane. FIG. 3 is a partially omitted side view of the automatic warehouse and is a view for explaining a rack and a stacker crane. In this embodiment, the left-right direction in FIGS. 1 and 2 is the front-rear direction X of the automatic warehouse 1, and the up-down direction in FIG. 1 and the left-right direction in FIG.

  The automatic warehouse 1 mainly includes a pair of racks 2 (first rack 2A and second rack 2B) and a pair of stacker cranes 3 (first stacker crane 3A and second stacker crane 3B).

(2) Rack The first rack 2A and the second rack 2B are arranged so as to sandwich the stacker crane passage 5 extending in the left-right direction Y of the automatic warehouse 1. The first rack 2A and the second rack 2B include a large number of front struts 7 arranged along the left-right direction Y at a predetermined interval, and rear struts 9 arranged behind the front strut 7 with a predetermined interval therebetween, It has a large number of article support members 11 provided on the front column 7 and the rear column 9. An article storage shelf 13 is constituted by a pair of left and right article support members 11, and a fork passage gap 15 that allows the slide fork 31 described later to move in the vertical direction is formed between them. As is apparent from the drawing, each article storage shelf 13 is arranged in a large number on the left, right, top and bottom, and an article W can be placed on each. Each article W is placed on the pallet P (see FIG. 2) and moved together with the pallet P.
A warehouse station 17 is disposed on one side of the second rack 2B, and a warehouse station 19 is disposed on one side of the first rack 2A.

(3) Stacker Crane Next, the first stacker crane 3A and the second stacker crane 3B will be described with reference to FIGS. 1 and 2, the structures of the first stacker crane 3A and the second stacker crane 3B are simplified.

  The first stacker crane 3 </ b> A and the second stacker crane 3 </ b> B can travel in the vicinity of the rack 2 in parallel and can transfer the article W between the rack 2. Hereinafter, the stacker crane will be described in more detail. Between the first rack 2A and the second rack 2B, a first traveling rail 21A and a second traveling rail 21B arranged in the front-rear direction X of the automatic warehouse 1 along the stacker crane passage 5 are provided. Each of the first traveling rail 21A and the second traveling rail 21B has a pair of upper and lower rails 26, by which the first stacker crane 3A and the second stacker crane 3B can move in the horizontal direction Y of the automatic warehouse 1. It is guided to be movable.

  The first stacker crane 3A and the second stacker crane 3B mainly include a traveling carriage 22, a pair of masts 23 (left mast 23A, right mast 23B) provided on the traveling carriage 22, a left mast 23A, and a right mast 23B. An upper frame 25 that connects the upper ends of the two, a traveling wheel 27 provided on the traveling carriage 22, a lifting platform 29 that is mounted on the left mast 23A and the right mast 23B so as to be movable up and down, and an advance / retreat mechanism (see FIG. And a slide fork 31 slidably provided in the front-rear direction X. The lifting platform 29 has a lifting guide roller 34 guided by the left mast 23A and the right mast 23B.

  Since the slide fork 31 is slidable on both sides in the front-rear direction X, it can access both the first rack 2A and the second rack 2B. That is, the slide fork 31 can transfer the article W between the rack adjacent to the traveling rail on which the own machine travels and the rack adjacent to the traveling rail on which the other apparatus travels.

  2 and 3, the pallet P and the article W are placed on the slide fork 31 of the lift 29.

  In the following description, the lifting platform 29 and the slide fork 31 are collectively described as a transfer unit. There may be a case where the article W and the pallet P are mounted on the transfer section, and a case where the article W and the pallet P are not mounted. Hereinafter, the transfer unit of the first stacker crane 3A is referred to as a first transfer unit 32A, and the transfer unit of the second stacker crane 3B is referred to as a second transfer unit 32B.

32 A of 1st transfer parts and the 2nd transfer part 32B move in the two-dimensional plane (YZ plane of FIG. 3) formed by the horizontal and the raising / lowering direction, and carry in / out of the articles | goods W. As shown in FIG. . The first transfer unit 32A and the second transfer unit 32B are freely movable in a plane by a combination of the traveling operation of the traveling carriage 22 and the lifting operation of the lifting device. Further, the first transfer unit 32A and the second transfer unit 32B can be present at any position as long as they do not interfere with each other in the above-described two-dimensional plane.
However, as is clear from FIG. 2, the positions of the first transfer portion 32A and the second transfer portion 32B in the front-rear direction X overlap each other. Accordingly, the first stacker crane 3A and the second stacker crane 3B can pass in the left-right direction Y only when the first transfer unit 32A and the second transfer unit 32B are completely displaced in the vertical direction. It is.

  As shown in detail in FIG. 3 (not shown in FIGS. 1 and 2), the first stacker crane 3A and the second stacker crane 3B have a control panel 33, a traveling motor 35, and a lifting motor 37. . The control panel 33 is provided on the further rear side of the right mast 23B. The travel motor 35 is provided on the left mast 23A. The elevating motor 37 is provided on the left mast 23A.

  The control panel 33 includes electrical equipment such as an inverter, a converter, and a breaker for the travel motor 35 and the lifting motor 37 inside. The control panel 33 houses a crane controller which will be described later.

  As shown in FIG. 3, the lifting motor 37 can drive the drum 41. A wire 43 extends from the drum 41. The wire 43 is wound around a roller 44 provided on the upper frame 25, and is further connected to the lifting platform 29.

(4) Stacker Crane Control Configuration Next, the control configuration of the automatic warehouse 1 will be described with reference to FIGS. 4 and 5. FIG. 4 is a functional block diagram showing an automatic warehouse control configuration as the first embodiment. FIG. 5 is a functional block diagram showing an automatic warehouse control configuration as the second embodiment.

In FIG. 4, a system controller 45, a first crane controller 47A, and a second crane controller 47B are shown. The first crane controller 47A is mounted on the first stacker crane 3A and controls the operation of the first stacker crane 3A. The second crane controller 47B is mounted on the second stacker crane 3B and controls the operation of the second stacker crane 3B. The system controller 45 is a controller higher than the first crane controller 47A and the second crane controller 47B, and can communicate with the first crane controller 47A and the second crane controller 47B.
In the first embodiment shown in FIG. 4, the first crane controller 47 </ b> A and the second crane controller 47 </ b> B communicate with each other only via the system controller 45. In the second embodiment shown in FIG. 5, the first crane controller 47 </ b> A and the second crane controller 47 </ b> B can communicate directly without going through the system controller 45.
Note that the data transmitted and received between the first crane controller 47A and the second crane controller 47B include state data for notifying normality / abnormality, conveyance data being executed, and the current position.

  Next, the 1st crane controller 47A arrange | positioned in the control panel 33 is demonstrated using FIG. FIG. 6 is a functional block diagram of the control unit of the stacker crane. Since the second crane controller 47B is the same as the first crane controller 47A, the description thereof is omitted. Further, the first crane controller 47A and the second crane controller 47B may not be mounted on the stacker crane.

  The first crane controller 47 </ b> A includes a main controller 53, a travel control unit 55, a lift control unit 57, and a transfer control unit 59. These control units include computer hardware such as a CPU and a memory. In FIG. 6, these control units are expressed as functional blocks realized by the cooperation of the computer hardware and software. These control units may be realized by a single computer having a plurality of functions.

  The main controller 53 can communicate with the travel control unit 55, the elevation control unit 57, and the transfer control unit 59. Further, the main controller 53 can communicate with the system controller 45 and the second crane controller 47B. Communication occurs regularly or as needed.

  The traveling control unit 55 is a control unit for controlling the traveling / stopping of the traveling wheel 27, and is connected to the traveling motor 35 and the rotary encoder 63. The lifting control unit 57 is a control unit for moving the lifting platform 29 up and down along the left mast 23 </ b> A and the right mast 23 </ b> B, and is connected to the lifting motor 37 and the rotary encoder 65. The transfer control unit 59 is a control unit for moving the slide fork 31 in the front-rear direction X, and is connected to the transfer motor 67 and the rotary encoder 69.

  The first crane controller 47A further includes a storage unit 70. The storage unit 70 is a rewritable recording medium such as a RAM or a hard disk. The storage unit 70 stores a FreeStep table 71 described later.

The function of the main controller 53 will be described with reference to FIG. FIG. 7 is a functional block diagram of the main controller. The main controller 53 includes a trajectory calculation unit 72, a trajectory selection unit 73, a step division unit 74, a step calculation unit 75, an interference determination unit 76, another machine operation completion grasping unit 77, and a stop position setting unit 78. And a comparison unit 79.
The trajectory calculation unit 72 calculates trajectories that are candidates for the first transfer unit 32A. The trajectory selection unit 73 selects an optimal trajectory from a plurality of trajectories calculated by the trajectory calculation unit 72. The step division unit 74 divides the time or distance in the planned travel route into a plurality of steps. The step calculation unit 75 calculates a step (FreeStep) in which interference may occur by considering the mutual distance, moving direction, and speed of both transfer units. The interference determination unit 76 determines the presence or absence of interference by calculating the positions of both transfer units for FreeStep. The other machine operation completion grasping unit 77 grasps the Step at which the other machine operation is completed. The stop position setting unit 78 changes the stop position of the own machine to a position away from the target position by a predetermined distance when it is determined that the both transfer units interfere with each other at each target position. If it is determined that the two transfer units interfere with each other at the respective target positions, the comparison unit 79 compares the movement times or the movement distances of the two transfer units.

(5) Outline Description of Trajectory Determination Process The trajectory determination process before starting movement from the idle state where the transfer unit has stopped will be described with reference to FIG. FIG. 8 is a flowchart showing the trajectory determination process by the main controller.
In the following description, the first transfer unit 32A of the first stacker crane 3A will be described as a movement target.

  The trajectory calculation unit 72 of the main controller 53 performs normal trajectory calculation in S1, and then in S2, the interference determination unit 75 determines whether the first transfer unit 32A interferes with the second transfer unit 32B. Ordinary trajectory calculation is the determination of interference by trajectory selection. Note that “Yes” in S3 means that a trajectory that can avoid interference between the first transfer unit 32A and the second transfer unit 32B could not be selected in the normal trajectory calculation of the partial movement time. If “Yes” in S2, the process proceeds to S4. If “No” in S <b> 2, the process proceeds to S <b> 3, and the main controller 53 determines whether or not the calculation for the total movement time has been completed. If “No” in S3, the process returns to S1, and the main controller 53 performs normal trajectory calculation and interference determination. If “Yes” in S3 (that is, if it is determined that interference can be avoided by selecting a trajectory), the process proceeds to S10. In S <b> 10, the main controller 53 transmits the calculation result to the travel control unit 55. As a result, the traveling control unit 55 causes the first transfer unit 32A to travel along the selected track.

  The trajectory calculation unit 72 calculates an avoidance trajectory in S4, and the interference determination unit 76 determines whether or not interference occurs by calculation of the avoidance trajectory in S5. The calculation of the avoidance trajectory is to obtain a trajectory that can avoid interference by correcting the trajectory condition in the selected trajectory. Note that “Yes” in S5 means that an avoidance trajectory that can avoid interference between the first transfer unit 32A and the second transfer unit 32B could not be obtained in the avoidance trajectory calculation of the partial movement time. In addition, here, “the avoidance trajectory could not be obtained” means, for example, a range set in consideration of efficiency (calculation time and detour distance) except when the target position is close and cannot be avoided Including the case of exceeding. If “Yes” in S5, the process proceeds to S7, and if “No” in S5, the process proceeds to S6. In S6, the main controller 53 determines whether or not the calculation for the total movement time has been completed. If “Yes” in S6 (that is, if it is determined that the interference can be avoided by correcting the orbital condition), the process proceeds to S10. Thereby, although the optimal trajectory is not guaranteed, the first transfer unit 32A can reach the target position earlier under the conditions. Thereafter, the traveling control unit 55 causes the first transfer unit 32A to travel based on the corrected track condition.

  If “Yes” in S5 (that is, if it is determined that the interference cannot be avoided by correcting the orbital condition), the process proceeds to S7. In S7, the trajectory calculation unit 72 performs a delay trajectory calculation. The delay trajectory calculation is a calculation of a movement start delay time for avoiding interference. In S8, “Yes” means that a trajectory that can avoid interference between the first transfer unit 32A and the second transfer unit 32B could not be obtained in the delay trajectory calculation of the partial movement time. In S8, the main controller 53 determines whether or not interference occurs. If “Yes” in S8, the process proceeds to S11, and if “No” in S8, the process proceeds to S9. In S11, the first crane controller 47A places the first transfer unit 32A in a standby state. In S9, the main controller 53 determines whether or not the calculation for the total movement time has been completed. If “Yes” in S9, the process proceeds to S10. As a result, the first transfer unit 32A starts moving toward the target position with a delay by the time obtained by the calculation. If “No” in S9, the process proceeds to S7.

  As described above, the trajectory determination algorithm shown in FIG. 8 determines whether or not there is interference in the order of the normal trajectory, the avoidance trajectory calculation, and the delay trajectory calculation. The reason why the avoidance trajectory calculation can be placed before the delay trajectory calculation in this way is that the calculation of the avoidance trajectory calculation is performed by selecting the detour trajectories in a predetermined order as will be described later. It is because it became possible to shorten.

(6) Interference Determination An algorithm for performing interference determination by obtaining FreeStep and calculating the positions of both transfer units will be described below with reference to FIG. FIG. 9 is a flowchart showing the interference determination process of the main controller. The algorithm shown in FIG. 9 is used for interference determination between the first transfer unit 32A and the second transfer unit 32B in the normal trajectory calculation of the interference determination flow shown in FIG. This algorithm is executed by each main controller 53 of the first crane controller 47A and the second crane controller 47B. Hereinafter, a case where the main controller 53 of the first crane controller 47 performs the interference determination of the first transfer unit 32A will be described.

  The time or distance until the first transfer unit 32A starts moving and reaches the target position is handled by being divided into a plurality of Steps. For example, 1 Step is 5 ms. The main controller 53 obtains a Step at which interference with the second transfer unit 32B of the second stacker crane 3B does not occur after the first transfer unit 32A starts moving as a FreeStep, and the first transfer unit 32A and the second transfer step in the FreeStep. The presence or absence of interference is determined by calculating the planned position where the transfer unit 32B exists. That is, in this algorithm, the position calculation of the first transfer unit 32A and the second transfer unit 32B is not performed for the step before FreeStep. Accordingly, the calculation load on the main controller 53 is reduced.

In S21 of FIG. 9, the step division unit 74 of the main controller 53 divides the time or distance in the planned movement route into a plurality of Steps.
Next, the main controller 53 initializes the FreeStep table 71 stored in the storage unit 70. The FreeStep table 71 includes, for example, an array (FreeStep [0] to FreeStep [2999]). Further, in S21, the main controller 53 sets FreeStep [0] to an initial value by substituting 0 for the subscript i of FreeStep [i] (i = 0).

  In S22, the main controller 53 acquires FreeStep and Step for completing the current operation of the second transfer unit 32B (other machine) of the second stacker crane 3B. In this embodiment, FreeStep is expressed as max (X_free step, Y_free step).

FreeStep max (X_free step, Y_free step) is obtained by the step calculation unit 75 of the main controller 53. The step calculation unit 75 selects FreeStep as a step having a high possibility of interference by considering the mutual distance, moving direction, and speed of both transfer units. More specifically, FreeStep is obtained as follows.
First, under the condition where the first transfer unit 32A and the second transfer unit 32B interfere with each other, an X_free step that is a step of the X axis (travel axis) and a Y_free step that is a step of the Y axis (elevating shaft) are obtained. Calculated separately. Next, the magnitudes of X_free step and Y_free step are compared, and a larger value is selected as FreeStep. If the X-axis FreeStep and the Y-axis FreeStep are the same value, that value is selected as the FreeStep.

  The reason why the calculation of FreeStep is divided between the X axis and the Y axis is to simplify the calculation. Since the two objects to be determined for interference move on the plane, the interference occurs when the X axis and the Y axis overlap. Thus, since the X-axis and Y-axis overlap each other is an interference condition, if a position is obtained by paying attention to the larger value of both, it is appropriate as a FreeStep as a Step that may cause interference.

The calculation method of X_free step or Y_free step is obtained by using different formulas in the following four cases. In the following equation, the speed of the first transfer part 32A is V1, the speed of the second transfer part 32B is V2, the acceleration / deceleration of both is a, and the first transfer part 32A and the second transfer part 32B Let dx be the distance between. V1 and V2 are set to Vmax (maximum speed) for the purpose of setting conditions strictly so as not to overlook interference.
1) When V1 and V2 are in the same direction (both approach at a speed equal to or less than the maximum value Vmax of the speed difference between V1 and V2)

2) When V1 and V2 are facing in opposite directions (sides approaching each other) (both approach at a speed equal to or less than the maximum value 2VAmax of the speed wheels of V1 and V2)

3) When one of V1 and V2 is 0 (assuming one of V1 and V2 starts suddenly)


4) When both V1 and V2 are 0 (assuming that both V1 and V2 start suddenly)



The first transfer unit 32A and the second transfer unit 32B accelerate at an acceleration a, then reach a speed Vmax, then decelerate at a deceleration a, and finally stop at the reference distance. Represents the distance to.
Note that the above formula is an example, and another formula may be adopted.

  In S23, the main controller 53 substitutes FreeStep into the FreeStep table 71 in ascending order. Therefore, the smallest value of FreeStep is assigned to FreeStep [0].

  In S24, the main controller 53 determines whether or not there is an unprocessed (that is, interference check is not performed) FreeStep. Specifically, the main controller 53 determines whether or not FreeStep [i] exists. If there is an unprocessed FreeStep (in the case of “Yes”), the process proceeds to S25. On the other hand, if there is no unprocessed FreeStep (in the case of “No”), the process ends. In the case of the end of the process, it is determined that there is no interference in all FreeSteps, so the trajectory calculation is adopted.

  In S25, the other controller operation completion grasping unit 77 of the main controller 53 performs the operation (movement or transfer) currently performed by the second transfer unit 32B of the second stacker crane 3B between the target FreeStep and the next FreeStep. Whether or not to complete the above is determined. If the operation currently being performed by the second transfer unit 32B is completed (in the case of “Yes”), the process returns to S22. This is because if the operation currently performed by the second transfer unit 32B is completed, the main controller 53 needs to check the presence or absence of FreeStep in the next operation of the second transfer unit 32B. In S22, the step calculation unit 75 of the main controller 53 reacquires FreeStep. Specifically, max (X_free step, Y_free step) in a state where the second transfer unit 32B performs the following operation is obtained. On the other hand, if the operation currently being performed by the second transfer unit 32B is not completed (in the case of “No”), the process proceeds to S26.

  In S <b> 26, the interference determination unit 76 of the main controller 53 executes position calculation processing (FreeStep [i]). In the position calculation process (FreeStep [i]), each position calculation of the first transfer unit 32A and the second transfer unit 32B in FreeStep [i] is performed. The result of the position calculation is obtained with (x, y) coordinate values.

  In S <b> 27, the interference determination unit 76 determines whether or not the first transfer unit 32 </ b> A and the second transfer unit 32 </ b> B interfere with each other by calculating the positions of both transfer units for the target FreeStep. To do. In this case, it is determined that the first transfer unit 32A and the second transfer unit 32B interfere with each other if their areas are partially overlapped. If the first transfer unit 32A and the second transfer unit 32B do not interfere (in the case of “No”), the process proceeds to S29, and if the first transfer unit 32A and the second transfer unit 32B interfere with each other, the process is performed. Goes to S28.

  In S29, the main controller 53 sets FreeStep for which position calculation was performed immediately before being processed. Specifically, the main controller 53 increments the subscript i of FreeStep [i].

  In S28, the process proceeds to the next trajectory calculation process. This is because it has been found that interference between the first transfer unit 32A and the second transfer unit 32B occurs in the current trajectory calculation method.

(7) Examples The following examples will be described.
In Step 240 (the second transfer unit 32B is in a state of performing the current operation), the first transfer unit 32A and the second transfer unit 32B may interfere with each other.
In Step 1000, the second transfer unit 32B completes the current operation (for example, movement).
-In Step 1500 (the 2nd transfer part 32B is in the state which is performing the next operation | movement), there exists a possibility that the 1st transfer part 32A and the 2nd transfer part 32B may interfere.
In Step 2600, the first transfer unit 32A completes the movement (that is, the first transfer unit 32A arrives at the target position).

  In the following, the control operation of the main controller 53 will be described with reference to the flowchart of FIG. In the following explanation, explanation will be made focusing on important points.

  First, in S22, the main controller 53 acquires Step 240 as Free Step, and also acquires Step 1000. Note that Step 1000 is a step in which the other machine completes its operation and is not FreeStep, but in this embodiment, it is handled in common with FreeStep for convenience of processing. In S23, the main controller 53 substitutes the values of the FreeSteps into the FreeStep table in ascending order. As a result, for example, 240 is substituted for FreeStep [0] and 1000 is substituted for FreeStep [1].

  In S24, since FreeStep [0] is unprocessed, the process proceeds to S25 (“Yes” in S24). In this case, since the second transfer unit 32B does not complete the current operation between Step 240 and Step 1000, the process proceeds to S26. In S26, the main controller 53 calculates the positions of the first transfer unit 32A and the second transfer unit 32B in Step 240, and in S27, whether or not the first transfer unit 32A and the second transfer unit 32B interfere with each other. Determine whether. If it is determined in Step 240 that interference occurs, it has been found that the interference cannot be avoided in the currently acquired trajectory calculation process, so the process proceeds to S28 and performs the following type of trajectory calculation process.

  If the first transfer unit 32A and the second transfer unit 32B do not interfere, the process returns to S24 through S29. In S24, since FreeStep [1] is unprocessed, the process proceeds to S25. In S25, since it is determined that the second transfer unit 32B completes the current operation (for example, movement) in Step 1000 after the processed Step 240, the process returns to S22. In S22, the main controller 53 reacquires FreeStep. Specifically, max (X_free step, Y_free step) in a state where the second transfer unit 32B performs the following operation is obtained. Actually, Step 1500 is a step in which the first transfer unit 32A and the second transfer unit 32B may interfere with each other in a state where the second transfer unit 32B performs the following operation. It is judged that there is. In S23, the main controller 53 assigns 1500 to FreeStep [2].

In this embodiment, the main controller 53 determines whether or not interference occurs in Step 1000 in S26 and S27. This is the result of sharing the processing with FreeStep. It is not necessary to perform the interference determination of the Step that has completed the operation.
Further, the main controller 53 determines whether or not interference occurs in Step 1500 in S26 and S27. In the present embodiment, even if the second transfer unit 32B completes the next operation in Step 2600 and subsequent Steps, the interference determination is not affected.

As described above, when the FreeStep after the timing at which the second transfer unit 32B completes the operation and starts the next operation is the target of position calculation (“Yes” in S25), the position calculation is performed. Before the execution, it is determined whether or not a new FreeStep is generated between the timing and the FreeStep (S22). When a new FreeStep is obtained, position calculation in the new FreeStep is performed (S27).
As another example, at the time of obtaining the first FreeStep, it is confirmed whether or not the second transfer unit 32B shifts to the next state. FreeStep may also be obtained. In that case, S25 is omitted in FIG.

(8) Trajectory selection operation (S1 and S2 in FIG. 8)
The normal trajectory calculation and interference determination (trajectory selection operation) will be described in detail with reference to FIGS. FIG. 10 is a flowchart showing the trajectory selection process of the main controller. FIG. 11 is a schematic diagram showing a plurality of trajectories between the starting position and the target position. FIG. 12 is a schematic diagram showing two trajectories between the starting position and the target position.

  The main controller 53 of the first crane controller 47A searches for the shortest time path that can avoid interference with the second transfer part 32B from among the plurality of shortest time paths before the first transfer part 32A starts to move. . The shortest time paths to be selected are only the two shortest time paths (first trajectory 181 and second trajectory 182) that constitute the boundary line of the upper, lower, left, and right regions diagonally from the starting position to the target position. .

Hereinafter, the selection process will be described in detail. The first transfer part 32A is movable in any direction of running and raising / lowering. The control in the running / lifting direction is independent, and a trapezoidal approximate speed table is given according to the moving distance of each axis. In FIG. 11, a plurality of trajectories (a first trajectory 181, a second trajectory 182, a third trajectory 183, and a fourth trajectory 184) are shown between the starting position 191 and the target position 193. In this case, since the distance in the traveling direction is longer than the distance in the ascending / descending direction, the traveling time in the traveling direction is longer than the traveling time in the ascending / descending direction. Each of these tracks has a constant time in the traveling direction, and is different by changing only the start timing of the up / down direction operation or the start timing and speed of the up / down direction operation. Specifically, the trajectory is shifted to the right side by delaying the start of movement in the vertical axis direction. This means that the trajectory with the shortest time can be selected from a plurality of candidates by adjusting the travel start time of the travel or lift within the range of the travel time of the travel axis minus the travel time of the lift axis.
In other words, the two shortest time paths are, in other words, the first trajectory when the shorter start time is the earliest compared to the longer time by comparing the traveling time from the starting position to the target position and the ascending / descending time, This is the second trajectory when it is slowest.

  Of these plural trajectories, the main controller 53 actually considers the first trajectory passing through the outermost side of the quadrangular (or parallelogram) region formed by the set of trajectories from the starting position to the target position. There are only 181 and fourth orbit 184. The first track 181 and the fourth track 184 are a combination of two tracks that are farthest from each other as a set of two tracks. Therefore, when interference occurs in both of the trajectories, there is no trajectory that can avoid the interference. That is, from the viewpoint of trajectory selection, it is sufficient to select either the first trajectory 181 or the fourth trajectory 184.

  In this automatic warehouse 1, the main controller 53 searches for only the two shortest time paths. Therefore, the amount of calculation required for the trajectory search process is reduced. As a result, the main controller 53 can determine the trajectory in a short period. The number of trajectories is usually two, but for example, when moving in the horizontal direction or the vertical direction, the number of trajectories is one.

In S31 of FIG. 10, the main controller 53 grasps the position of the second transfer unit 32B, which is another machine, and the first transfer unit 32A has the first track 181 and the second transfer unit 32B. It is determined which of the fourth tracks 184 is an outer track. Specifically, it is determined whether or not the second transfer part 32B exists on the side of the straight line connecting the starting position and the target position, and the track on the opposite side of the second transfer part 32B of the straight line. Is selected as the outer orbit. In the example as shown in FIG. 12, the first track 181 is an outer track with respect to the second transfer portion 32B.
In S31, the main controller 53 determines whether or not the first track 181 that is an outer track with respect to the second transfer unit 32B is safe. At the time of this determination, the interference determination process of FIG. 9 is executed. If it is determined to be safe, the process proceeds to S32. In S32, the main controller 53 selects the first track 181 as the track.

  If it is determined in S31 that the first track 181 is not safe, the process proceeds to S33. In S33, it is determined whether or not the fourth track 184 is safe. At the time of this determination, the interference determination process of FIG. 9 is executed. If it is determined that the fourth track 184 is safe, the process proceeds to S32. In S32, the main controller 53 selects the fourth track 184 as the track.

  If it is determined in S33 that the fourth track 184 is not safe, the process proceeds to S34. In S34, the first crane controller 47A determines not to select a trajectory.

  As described above, since the number of trajectories to be selected is limited, the calculation load is reduced. Furthermore, since the order of trajectories to be selected is selected, the possibility of selecting the trajectory determined first is increased as a result, and the calculation load is reduced.

(9) Selection of avoidance method by changing orbital conditions (S4 and S5 in FIG. 8)
The avoidance trajectory calculation and interference determination (selection of avoidance technique by changing trajectory conditions) will be described with reference to FIG. FIG. 13 is a schematic diagram for explaining a method in which one transfer unit travels a detour route when there is a possibility that the transfer units interfere with each other.
In the example of FIG. 13, the planned traveling track of the second transfer unit 32B is included in the planned traveling track of the first transfer unit 32A. More specifically, the first transfer unit 32A has a target position behind the second transfer unit 32B and travels toward the second transfer unit 32B. The second transfer unit 32B has a target position on the front side of the first transfer unit 32A and travels toward the first transfer unit 32A. However, it is predicted that the first transfer unit 32A and the second transfer unit 32B collide at the interference position 195. In this embodiment, considering the movement of the first transfer unit 32A, interference cannot be avoided even if the travel start time is delayed. Therefore, a method in which the first transfer unit 32A travels on the detour route 121 passing through the route position 120 is used. adopt.

FIG. 14 is a schematic diagram for explaining a method of delaying the travel start timing of one transfer unit when there is a possibility that the transfer units interfere with each other.
In the embodiment of FIG. 14, the planned traveling tracks of the first transfer unit 32 </ b> A and the second transfer unit 32 </ b> B partially overlap, but there are also portions that do not overlap each other. More specifically, the first transfer unit 32A has a position on the opposite side of the second transfer unit 32B as a target position, and travels toward the second transfer unit 32B. The second transfer part 32B has the position on the side of the first transfer part 32A as a target position, and initially travels toward the first transfer part 32A and deviates from the middle to the upper side in the drawing. However, it is predicted that the first transfer unit 32A and the second transfer unit 32B collide at the interference position 197. In this embodiment, considering the movement of the first transfer unit 32A, interference can be avoided by a method of sending the travel start timing of the first transfer unit 32A.
(10) Bisection method Next, the bisection method will be described with reference to FIG. FIG. 15 is a flowchart showing a process for determining the optimum value by the bisection method. The bisection method can be applied to both the setting of the bypass route and the setting of the departure start delay time.

First, a general bisection method will be described.
In S41, the main controller 53 sets a maximum value.
In S42, the main controller 53 searches for an intermediate point.

In S53, the main controller 53 determines whether or not there is interference between the first transfer unit 32A and the second transfer unit 32B when traveling under the condition of the intermediate point. If it is determined that there is interference, the process proceeds to S44, and the main controller 53 searches for an intermediate point in a region having a larger value as viewed from the reference intermediate point. If it is determined that there is no interference, the process proceeds to S45. In S45, the main controller 53 determines whether or not the post-division length (search step size) by the previous division is equal to or less than a predetermined value. If it is determined that it is below the predetermined value, the process ends. If it is determined that the predetermined value is exceeded, the process proceeds to S46, and the main controller 53 searches for an intermediate point in a region having a smaller value as viewed from the reference intermediate point.
After completion of S44 or S46, the process returns to S43.

(10-1) Setting of Via Position of Detour Route Next, the case where the bisection method is used for setting the via position of the detour route will be described with reference to FIG. FIG. 16 is a schematic diagram illustrating a process of determining a via position that is distant from the planned traveling track.

Hereinafter, the main controller 53 of the first transfer unit 32A will be described. In S41 of FIG. 15, in FIG. 16, the main controller 53 sets d as the maximum value in the direction in which the normal 178 of the intermediate point 177 in the vector 176 connecting the starting position 173 and the target position 175 of the first transfer unit 32A extends. Set _max . d _max is the maximum distance possible on the layout, and the direction is the region side where the second transfer unit 32B does not exist or the influence of the second transfer unit 32B is small in the two regions divided by the vector 176 Set to Thereby, interference of the 1st transfer part 32A and the 2nd transfer part 32B is prevented more reliably. d _max may be 3000 mm as a sufficiently large fixed value, for example.
As described above, since the point on which the normal line for obtaining the via position is drawn is the midpoint of the straight line connecting the starting position and the target position, the time required for the route search is shortened.

  In S42, the main controller 53 searches for an intermediate point. In FIG. 16, the intermediate point is indicated by (1).

  In S43, the main controller 53 determines whether or not there is interference between the first transfer unit 32A and the second transfer unit 32B when traveling by the distance of the first intermediate point (1). In this case, since there is no interference, the process proceeds to S45, and the main controller 53 determines whether or not the length after division by the immediately preceding division is equal to or less than a predetermined value. The predetermined value is, for example, 10 mm. In this case, since the predetermined value is exceeded, the process proceeds to S46. In S46, the main controller 53 searches for an intermediate point in a region having a smaller value when viewed from the intermediate point searched immediately before. In this case, the second intermediate point (2) is selected.

  Hereinafter, the flow of S43 to S46 is repeated, and the intermediate point moves to (1), (2), and (3). When the third intermediate point (3) is searched in S44, it is determined in S43 that there is no interference, and in S45, it is determined that the post-division length by the immediately preceding division is equal to or less than a predetermined value, and as a result, S47. Thus, the value of the third intermediate point (3) is set as the transit position. The via position is closest to the planned trajectory as long as interference does not occur. As a result, the travel route can be set short.

  It should be noted that the route position of the detour route only needs to be on one normal line on the line formed between the departure position and the target position. Therefore, for example, the main controller 53 may set the via position on the normal line at the interference position of the vector connecting the departure position and the interference position, starting from the collision point when the movement starts without delay. Such a case will be described with reference to FIG. FIG. 17 is a schematic diagram illustrating a process of determining a via position that is distant from the planned traveling track.

Hereinafter, the main controller 53 of the first transfer unit 32A will be described. In S41, in FIG. 17, the main controller 53 moves to the interference position 122 on the vector connecting the departure position and the interference position at the interference position 122 where the first transfer section 32A and the second transfer section 32B are expected to interfere. D _max as the maximum value is set in the direction in which the normal line 123 extends in the orthogonal direction. d _max is the same as in the previous embodiment.
As described above, since the point where the normal line for obtaining the via position is drawn is the collision point, the time required for the route search is shortened.

  In S42, the main controller 53 searches for an intermediate point. In FIG. 17, the midpoint is indicated by (1).

  In S43, the main controller 53 determines whether or not there is interference between the first transfer unit 32A and the second transfer unit 32B when the main controller 53 travels a distance of the first intermediate point (1). In this case, since there is no interference, the process proceeds to S45, and the main controller 53 determines whether or not the length after division by the immediately preceding division is equal to or less than a predetermined value. The predetermined value is, for example, 10 mm. In this case, since the predetermined value is exceeded, the process proceeds to S46. In S46, the main controller 53 searches for an intermediate point in a region having a smaller value when viewed from the intermediate point searched immediately before. In this case, the second intermediate point (2) is selected.

  Hereinafter, the flow of S43 to S46 is repeated, and the intermediate point moves to (1), (2), and (3). When the third intermediate point (3) is searched in S44, it is determined in S43 that there is no interference, and in S45, it is determined that the post-division length by the immediately preceding division is equal to or less than a predetermined value, and as a result, S47. Thus, the value of the third intermediate point (3) is set as the transit position. The via position is closest to the planned trajectory as long as interference does not occur. As a result, the travel route can be set short.

Once the via position is determined, it is possible to select two trajectories that constitute the boundary of the shortest time movable area as the trajectory from the starting point to the via position, and further, the shortest time movable area of the trajectory from the via position to the target position Two trajectories that make up the boundary can be selected.
The operation of selecting a detour trajectory passing through a waypoint will be described with reference to FIG. FIG. 18 is a schematic diagram illustrating selection determination of a detour trajectory passing through a via position. FIG. 18 shows a state where the transit position 115 is set in order for the first transfer unit 32A to avoid interference with the second transfer unit 32B. As is apparent from the figure, the first transfer section 32A moves from the starting position 114 to the via position 115 as the first detour path 112A and the second detour path 112B, and the first transfer section 32A passes through. The trajectory moving from the position 115 to the target position 116 includes a third bypass trajectory 113A and a fourth bypass trajectory 113B. The main controller 53 first determines on which side of the straight line connecting the starting position 114 and the via position 115 the interference position 122 exists, and then the first trajectory on the opposite side of the interference position 122 with respect to the straight line. One bypass track 112A is selected as the outer track. Further, the main controller 53 first determines on which side of the straight line connecting the via position 115 and the target position 116 the interference position 122 exists, and then in a trajectory opposite to the interference position 122 with respect to the straight line. A certain third detour track 113A is selected as the outer track. Since the first bypass trajectory 112A and the third bypass trajectory 113A selected in this way are combinations of trajectories with the lowest possibility of interference, safety is improved.
There are two methods for selecting a trajectory: a method in which each bypass trajectory is arbitrarily selected and interference is checked in order, and a method in which interference is checked from a bypass trajectory with a low possibility of interference. In the latter case, there is a method in which interference is first determined for a combination of detour trajectories with the lowest possibility of interference, and if it is determined that there is interference, interference determination is performed for other combinations of trajectories. For the interference determination, the interference determination algorithm of FIG. 9 may be used.
As a method for determining the trajectory, there are a method for determining a detour trajectory that is initially determined to have no interference as a final one, and a method for further determining whether or not all the detour trajectory combinations have interference.

  In the automatic warehouse 1, by setting the transit position through which the transfer unit is routed to a point on the normal line of the selected shortest time path, the processing load on the route search by the main controller is reduced. Therefore, the time required for route search is shortened.

(10-2) Setting of departure start delay time Next, the case where the bisection method is used for setting the departure start delay time will be described with reference to FIG. FIG. 19 is a time axis from 0 of “with interference” to t _{max of} “without interference”.

A description will be given based on the time axis 171. In S41, the main controller 53 sets t _max in FIG. 19 as the maximum value. For example, t _max is set to twice the scheduled movement time. t _max may be a time until the movement of the second transfer unit 32B is completed.

  In S42, the main controller 53 searches for an intermediate point of the entire time axis 171. In FIG. 19, the intermediate point is indicated by (1).

  In S43, the main controller 53 determines whether or not there is interference between the first transfer unit 32A and the second transfer unit 32B when the travel is delayed by the time of the first intermediate point (1). In this case, since there is no interference, the process proceeds to S45, and the main controller 53 determines whether or not the length after division by the immediately preceding division is equal to or less than a predetermined value. The predetermined value is, for example, 0.1 seconds. In this case, since the predetermined value is exceeded, the process proceeds to S46. In S46, the main controller 53 searches for an intermediate point in a region having a smaller value when viewed from the intermediate point searched immediately before. In this case, the second intermediate point (2) is selected.

Thereafter, the flow of S43 to S46 is repeated, and the intermediate point moves as (1), (2), (3), (4), (5). When the fifth intermediate point (5) is searched in S44, it is determined in S43 that there is no interference, and in S45, it is determined that the length between the intermediate points (4) and (5) is equal to or less than a predetermined value. As a result, the value of the fifth intermediate point (5) is set as the travel start delay time in S47. This value is a time in which the delay time is shortened as much as possible within a range where no interference occurs.
As described above, since the main controller 53 uses the bisection method to determine the time for delaying the start of movement, the time required for the route search is shortened.

(11) Special Case of Avoidance Trajectory Calculation The avoidance trajectory calculation when the target positions of the first transfer unit 32A and the second transfer unit 32B interfere with each other will be described with reference to FIG. In that case, it is almost determined that interference occurs in the normal trajectory calculation, and further, the calculation time becomes long in the avoidance trajectory. Therefore, a special avoidance trajectory is set here. FIG. 20 is a schematic diagram illustrating a standby operation when two transfer units try to access an article storage shelf that is the same or causes interference.

  In FIG. 20, the first transfer unit 32A and the second transfer unit 32B are approaching the target position 117. Hereinafter, the main controller 53 of the first transfer unit 32A will be described.

Before the start of the movement of the first transfer unit 32A, the main controller 53 performs the following control. If it is determined that the two transfer units interfere with each other at the target position 128, the comparison unit 79 compares the movement times or distances of the two transfer units. If it is determined that the moving time or moving distance for moving the first transfer unit 32A toward the target position 128 is longer than that of the second transfer unit 32B, the stop position setting unit 78 determines the stop position of the own machine. The standby position 129 is separated from the target position 128 by a predetermined distance. The standby position 129 is a position that is on a straight line connecting the current location and the target position 128 and is separated from the target position 128 by a distance r. The distance r is a distance in the vicinity of the target position 128 that is unlikely to come into contact with another transfer unit that moves toward the target position 128. Therefore, even if it is necessary to perform an avoidance operation when the first transfer unit 32A subsequently moves to the target position 128, the amount of time or distance for avoidance can be reduced.
The stop position setting unit 78 determines that the first transfer unit 32B has a shorter moving time or movement distance for moving toward the target position 128 than the second transfer unit 32B. The unit 32A is kept waiting at the current position. The reason is that it takes time to calculate an appropriate standby track of the first transfer unit 32A with respect to the track of the second transfer unit 32B.

  In a state where the first transfer unit 32A is waiting at the standby position 129, the main controller 53 starts the movement of the second transfer unit 32B from the target position 128 toward another position, and the first transfer unit Even if the part 32A moves to the target position 128, it waits until both transfer parts do not interfere. Specifically, after receiving information notifying that the second transfer unit 32B has moved away from the target position 128, the first transfer unit 32A starts moving.

(12) Second Embodiment A trajectory determination operation in the second embodiment will be described with reference to FIGS. 21 and 22. In this embodiment, the sub-optimal solution can be selected by repeatedly performing the avoidance trajectory calculation and the delay trajectory calculation within a predetermined time. FIG. 21 is a functional block diagram of the main controller in the second embodiment. FIG. 22 is a flowchart showing the trajectory determination process in the second embodiment.

As illustrated in FIG. 21, the main controller 153 includes a time limit management unit 155 and a repetitive execution unit 156 in addition to the functions illustrated in the first embodiment. The time limit management unit 155 manages the time limit for trajectory calculation. The repetition execution unit 156 causes the trajectory calculation unit 72 to repeatedly execute trajectory calculation within the time limit.
The main controller 53 of the first crane controller 47A performs normal trajectory calculation in S51, and then whether or not the first transfer unit 32A interferes with the second transfer unit 32B in the normal trajectory calculation of the partial movement time in S52. Judging. If “Yes” in S52, the process proceeds to S34. If “No” in S <b> 52, the process proceeds to S <b> 53, and the main controller 53 determines whether or not the calculation for the total movement time has been completed. If “No” in S53, the process returns to S51, and the main controller 53 performs normal trajectory calculation and interference determination. If “Yes” in S53 (that is, if it is determined that the interference can be avoided by selecting the trajectory), the process proceeds to S62. In S <b> 62, the main controller 53 transmits the calculation result to the travel control unit 55. As a result, the traveling control unit 55 causes the first transfer unit 32A to travel along the selected track.

  The trajectory calculation unit 72 calculates an avoidance trajectory in S54, and the time limit management unit 155 determines whether or not the allowable calculation time α has been exceeded in S55. In this embodiment, α is 0.09 seconds. If “Yes” in S55, the process proceeds to S60. If “No” in S55, the process proceeds to S56. In S56, the repeated execution unit 156 determines whether an end condition has been reached. The end condition is, for example, a case where the number of repeated position calculations reaches a predetermined number. If “Yes” in S56, the process proceeds to S57. If “No” in S56, the process returns to Step 54 and the avoidance trajectory calculation is performed again. The avoidance trajectory calculation finds another solution each time it is repeated. The other solution is, for example, to select a detour trajectory that has not yet been selected, or if the bisection method is used, the second calculation is performed with a predetermined value that is a criterion for stopping the calculation smaller than the first calculation. This is the trajectory obtained by setting the position of the via point more finely.

  The trajectory calculation unit 72 performs delay trajectory calculation in S57, and the time limit management unit 155 determines whether or not the predetermined time α has been exceeded in S58. If “Yes” in S58, the process proceeds to S50. If “No” in S58, the process proceeds to S59. In S59, the repeated execution unit 156 determines whether or not an end condition has been reached. The end condition is, for example, a case where the number of repeated position calculations reaches a predetermined number. If “Yes” in S59, the process proceeds to S60. If “No” in S59, the process returns to S57 and the delay trajectory calculation is performed again. The delay trajectory calculation increases the accuracy of the position calculation every time it is repeated. For example, in the case of the bisection method, the number of calculations for obtaining the position of the intermediate point is increased in the second calculation than in the first calculation.

  In S60, the trajectory selection unit 73 of the main controller 53 determines whether there is a solution. “Solution” means that a path without interference is obtained in the avoidance trajectory calculation or the delay trajectory calculation. If “Yes” in S60, the process proceeds to S61, and if “No”, the process proceeds to S52. In S61, the main controller 53 selects an optimal solution from a plurality of solutions. An optimal solution is a travel route that requires less travel time on the premise that the risk of interference is sufficiently low. In S52, the main controller 53 places the first transfer unit 32A in a standby state. When S61 ends, the process proceeds to S62. In S <b> 62, the main controller 53 transmits the calculation result to the travel control unit 55. As a result, the traveling control unit 55 causes the first transfer unit 32A to travel along the selected track.

  As described above, in the first embodiment, the interference determination is performed based on the initially selected trajectory, but in the second embodiment, the allowable calculation time α without performing the interference determination in the avoidance trajectory calculation and the delay trajectory calculation. The operation is repeated inside. If it is determined that there is interference, the process proceeds to the next trajectory calculation. If it is determined that there is no interference, the trajectory calculation is selected. In the second embodiment, a plurality of trajectory calculations are performed within an allowable calculation time, and the optimum one is selected from them. Therefore, for example, it is possible to select a trajectory that is not selected in the interference determination of the first embodiment, but does not actually interfere, and has a short movement time, that is, high operating efficiency.

(13) Other Embodiments Although one embodiment of the present invention has been described above, the present invention is not limited to the above embodiment, and various modifications can be made without departing from the scope of the invention. In particular, a plurality of embodiments and modifications described in this specification can be arbitrarily combined as necessary.
(A) In the above-described embodiment, the normal trajectory calculation, the avoidance trajectory calculation, and the delay trajectory calculation are combined in a certain order. However, these operations may be realized individually or in other combinations. It may be realized with.
(B) In the above embodiment, an automatic warehouse in which the transfer unit travels and moves up and down is adopted as the mobile body system, but the present invention is not limited to this. For example, the present invention can be applied to a transport vehicle system in which a plurality of transport vehicles travel on the ground. In that case, the interference prevention control in the horizontal plane of conveyance vehicles is performed.

  The present invention can be widely applied to a moving body system in which a plurality of moving bodies can move within a plane range.

DESCRIPTION OF SYMBOLS 1 Automatic warehouse 2 Rack 2A 1st rack 2B 2nd rack 3 Stacker crane 3A 1st stacker crane 3B 2nd stacker crane 5 Stacker crane passage 7 Front support 9 Rear support 11 Article support member 13 Article storage shelf 15 Fork passage gap 17 Warehousing station 19 Unloading station 21A First traveling rail 21B Second traveling rail 22 Traveling carriage 23 Mast 23A Left mast 23B Front mast 25 Upper frame 26 Rail 27 Traveling wheel
29 Lift platform 31 Slide fork 32A 1st transfer part (1st moving body)
32B 2nd transfer part (2nd moving body)
33 Control Panel 34 Lifting Guide Roller 35 Traveling Motor 37 Lifting Motor 41 Drum 43 Wire 44 Roller 45 System Controller 47A First Crane Controller 47B Second Crane Controller 53 Main Controller (Control Unit)
55 Travel Control Unit 57 Elevation Control Unit 59 Transfer Control Unit 63 Rotary Encoder 65 Rotary Encoder 67 Transfer Motor 69 Rotary Encoder 70 Storage Unit 71 FreeStep Table 72 Trajectory Calculation Unit 73 Trajectory Selection Unit 74 Step Division Unit 75 Step Calculation Unit 76 Interference Determining unit 77 Other unit operation completion grasping unit 78 Standby position setting unit 79 Comparison unit 112A First detour track 112B Second detour track 113A Third detour track 113B Fourth detour track 114 Departure position 115 Via position 116 Target position 117 Target position 120 Via position 122 Interference position 123 Normal 128 Target position 153 Main controller 155 Time limit management section 156 Repeat execution section 171 Time axis 173 Start position 175 Target position 176 Vector 177 Intermediate point 178 Normal 181 First trajectory 182 First 2 tracks 183 3rd track 184 4th track 191 Start position 193 Target position 195 Interference position 197 Interference position P Pallet W Article

Claims (7)

A first moving body and a second moving body arranged to be movable in a plane;
A control unit for confirming interference between the first moving body and the second moving body in a planned movement path of the first moving body before the first moving body starts moving;
The controller is
A step division unit that divides the time or distance in the planned movement route into a plurality of steps;
A step calculating unit that calculates a step in which interference does not occur by considering the mutual distance, moving direction, and speed of the first moving body and the second moving body;
The presence or absence of interference is determined by calculating the positions of the first moving body and the second moving body. an interference determination unit omitted position calculation, it has a,
The step calculating unit uses a maximum speed specification value as the speed .   The step calculation unit calculates a step that may cause interference by considering a mutual distance, a moving direction, and a speed of the first moving body and the second moving body, and may further cause interference. The mobile system according to claim 1, wherein a step prior to a certain step is selected as a step that is unlikely to cause interference. Step calculation unit, the first when the mobile body or the second moving body is stopped, using the conditions to initiate immediately accelerated from the state that is stopped, according to claim 1 or 2 Mobile system. The control unit further includes a grasping unit that grasps a step in which the operation of the second moving body is completed,
The step calculation unit is not only before the step of completing the operation of the second moving body, but also the mutual distance between the first moving body and the second moving body in the step of completing the operation of the second moving body, The mobile body according to any one of claims 1 to 3 , wherein a step that may cause interference is calculated after the step of completing the operation of the second mobile body in consideration of a moving direction and a speed. system. The controller is
When it is determined that the first moving body and the second moving body interfere with each other at the target position, the apparatus further includes a standby position setting unit for waiting the first moving body at a predetermined distance from the target position. The mobile body system according to any one of claims 1 to 4 . The controller is
If it is determined that the first moving body and the second moving body interfere with each other at the target position, the comparison section further includes a comparison unit that compares the moving time or the moving distance between the first moving body and the second moving body. ,
The standby position setting unit separates the standby position of the first moving body from the target position by a predetermined distance if the moving time or moving distance of the first moving body is longer than the moving time or moving distance of the second moving body. set the position to set the waiting position of the first moving body of the first moving body when the moving time or moving distance is shorter than the travel time or travel distance of the second movable body of the current position, according to claim 5 The mobile system described in 1. The controller is
A trajectory calculation unit for calculating a trajectory in which the first moving body and the second moving body do not interfere with each other;
A time limit management unit for managing the time limit of the trajectory calculation;
A repeat execution unit that repeatedly causes the trajectory calculation unit to execute trajectory calculation within the time limit;
A trajectory selector for selecting an optimal trajectory from a plurality of trajectories calculated by the trajectory calculator;
The mobile system according to any one of claims 1 to 6 , further comprising: