JP7837656B2 - Conveying device - Google Patents

Description

This invention relates to a conveying device for transporting goods corresponding to storage units to be stored in a work area, including storage units in automated warehouses and the like.

In manufacturing plants and distribution centers, various goods are often transported and stored in automated warehouses and other storage facilities. For example, manufacturing plants and distribution centers typically have multiple storage facilities. Each of these facilities often has a specific role, tailored to storage regulations and work processes.

Depending on the role, a conveying device is used to transport and store goods corresponding to multiple storage units. A certain type of goods, A, is stored in its corresponding storage unit A. Another type of goods, B, is stored in its corresponding storage unit B. The conveying device transports the goods to the appropriate storage unit according to this correspondence between goods and storage units.

Goods stored in a storage facility are then moved on to the next manufacturing or distribution process. In other words, they await the next process in the storage facility. The storage facility where the goods are stored has a corresponding relationship to the next process for that particular goods.

For example, item A, stored in storage unit A, is used in the next manufacturing process. Item B, stored in storage unit B, is used in the next distribution process. In factories and distribution centers equipped with storage units and conveying equipment, goods transported by transport equipment are conveyed by the conveying equipment and stored in the storage units. Alternatively, goods handed over from another process are conveyed by the conveying equipment and stored in the corresponding storage units.

The transport device is responsible for transporting goods to the corresponding storage compartments.

Factories and distribution centers are equipped with multiple storage facilities, and goods are stored in one of these facilities. For this storage, the transport system is required to transport the goods to the appropriate storage facility.

To meet these requirements, the conveying system is equipped with a circular conveyor that circles (rounds) multiple storage units, and supply conveyors that branch off from the circular conveyor to each storage unit at corresponding locations. The goods supplied to the circular conveyor move towards the storage unit where they are to be stored as they circulate along the conveyor.

When you approach, you move to the supply conveyor that branches off from the circular conveyor, and then move along the supply conveyor. The supply conveyor moves the incoming cargo from the branched conveyor to the storage area. Once you move, the cargo is stored in the storage area.

Such conveying devices and related technologies have been proposed (see, for example, Patent Documents 1, 2, and 3).

Japanese Patent Publication No. 2013-220362 Japanese Patent Publication No. 2000-247406 Japanese Patent Publication No. 2002-2928

Patent Document 1 discloses a package sorting system comprising a package detection device for detecting the sorting destination of packages, a video codec server for storing images detected by the package detection device when the sorting destination cannot be detected by the package detection device, and a video codec device that allows an employee to input the sorting destination while confirming the image received from the video codec server.

Patent Document 2 discloses a conveyor system in which, when a pallet retrieved from a pallet warehouse is placed on an input conveyor 13, the input conveyor 13 sends the pallet to a circulating transport conveyor side 11. Synchronized with this, a corresponding transport direction switching device 12 switches from "pass-through mode" to "merging mode."

Patent Document 3 discloses a sorting device configured to receive various goods 1, which are randomly placed with random destinations and transport order, transport them along a main transport path 11, automatically sort the goods according to a sorting plan, and control a robot 30 to automatically stack them at predetermined stacking locations (A1-A3, B1-B3) for transport. Furthermore, it includes a congestion buffering means 20 having a circulating path upstream of the branch transport paths 12a and 12b, which serve as the goods retrieval locations for the robot 30, for temporarily storing the goods.

Patent Document 1 describes a method for storing goods (packages) in a designated storage area, including verification by a worker. Patent Document 2, conversely to Patent Document 1, discloses a technique for sending goods removed from the storage area onto a circular conveyor belt to complete the required number of rotations.

None of the Patent Documents 1 to 3 directly disclose a method of transporting goods to multiple storage units by circulating the goods in a loop and moving them from the necessary branching points to supply conveyors. However, they do disclose the transfer of goods between the circulation route and the storage units.

However, conventional technology had the following problems:

The circular conveyor belt runs in a loop to accommodate multiple storage units. Along this loop, there are branches at multiple points corresponding to the locations of each storage unit. From each of these branches, supply conveyors extend towards the corresponding storage units.

On a circular conveyor belt, multiple packages are moving. Each of these packages may or may not be intended for the same storage unit. For example, package A should be stored in storage unit A, and package B should be stored in storage unit B. Thus, multiple packages, each destined for a different storage unit, are moving simultaneously on the circular conveyor belt.

Furthermore, there is a limit to the number of items that can be moved on a supply conveyor. Therefore, it is entirely possible for a supply conveyor to become completely full. For example, supply conveyor A, which connects to storage unit A, may become completely full.

On a circular conveyor belt, cargo A, which should be stored in storage unit A, and cargo B and C, which should be stored in other storage units, are circulating. At this time, if supply conveyor belt A is full, it is possible that the next cargo A may reach the branching point between supply conveyor belt A and the circular conveyor belt. Because supply conveyor belt A is full, cargo A will be held up at this branching point.

On the other hand, the circular conveyor belt moves cargo in a circular motion in a certain direction. This means that other cargo, such as cargo B, which should be moved to storage unit A, may reach this branching point. Cargo B, however, is also held up at the branching point by cargo A, preventing it from moving on the circular conveyor belt and thus becoming immobilized.

Of course, the next shipment might also be delayed.

In this situation, where goods destined for multiple different storage facilities are mixed together and moving along a circular conveyor belt, the goods may become stuck at a branching point to a particular supply conveyor belt due to factors such as the storage facilities, the capacity to move goods between storage facilities, the capacity of the supply conveyor belts, and the movement capacity of the supply conveyor belts.

As the size of the cargo storage system using conveying equipment increases, and the types and quantities of cargo being transported also increase, these problems become more apparent.

When a shipment becomes stuck, a vacant space is created in the supply conveyor causing the delay. This delay continues until the shipment A, which should be entering that supply conveyor, moves onto supply conveyor A.

This situation leads to stagnation during the circular conveyor's rotation, resulting in overall stagnation during transport. As mentioned above, the larger the cargo storage system, the more pronounced and longer this stagnation becomes.

The prior art described in Patent Documents 1-3, etc., did not anticipate the occurrence of delays and stagnation in luggage storage systems, nor did they anticipate an increase in the type or quantity of luggage.

Furthermore, Patent Document 3 describes a system for sorting packages at a branch off from a straight transport path. In this system, a buffer is provided before the branch. However, since it only provides a buffer, there is a problem that if the number of packages exceeds the buffer, the sorting process will stall. In particular, because the system is based on a straight transport path, if the buffer is overloaded, the transport path will also experience prolonged periods of stagnation.

In view of the above problems, the present invention aims to provide a conveying device that, when a load becomes stuck at a branching point, circulates the stuck load before it can enter the supply conveyor, thereby resolving the bottleneck of the load stuck at the next position.

In view of the above problems, the present invention provides a conveying device comprising a circular conveyor that circulates in accordance with multiple work areas and moves cargo in a circular manner,
The aforementioned circular conveyor includes multiple supply conveyors that move goods into the work areas from branching points corresponding to each of the multiple work areas,
A conveyor control unit that controls the circular movement of the aforementioned circular conveyor,
A supply conveyor control unit controls the storage movement on the supply conveyor,
A conveyor belt state detection unit for detecting the rotational state of the cargo on the aforementioned conveyor belt,
The system includes a stagnation control unit that controls the stagnation of circular movement at the aforementioned branching point,
The plurality of supply conveyors include a first supply conveyor, a second supply conveyor, ..., an Nth supply conveyor, corresponding to each of the plurality of work areas, which are the first work area, the second work area, ..., the Nth work area.
The aforementioned cargo includes one or more first cargo items of a type to be stored in the first work area, one or more second cargo items of a type to be stored in the second work area, ... one or more nth cargo items of a type to be stored in the N work area,
The multiple branching positions include the first branching position, the second branching position, ... the Nth branching position, corresponding to the first supply conveyor, the second supply conveyor, ... the Nth conveyor,
The aforementioned circular conveyor control unit is:
The first load is transferred to the first supply conveyor at the first branching position.
The second load is then transferred to the second supply conveyor at the second branching point, and...
The aforementioned N load is transferred to the N supply conveyor at the N branching position,
The aforementioned circular conveyor state detection unit is capable of detecting stopped cargo at any of the first to Nth branch positions and stagnant cargo stopped behind said stopped cargo.
If the stall control unit detects the stalled cargo, it will cause the stalled cargo to wait for a predetermined time at the branching position where it is stopped.
The stagnation control unit, based on at least one of the following: the number of packages in the "stagnation supply conveyor," which is the supply conveyor corresponding to the stopped packages; the density of the packages; the number relationship with the upper limit of the number of packages; the position of the packages on the stagnation supply conveyor; and the movement state of the stagnation supply conveyor,
If at least one of the density of packages in the aforementioned stagnant supply conveyor and the number relationship between the density of packages and the maximum number of packages is less than or equal to a predetermined value,
(Process 1) In response to the elapsed waiting time of the predetermined time, an extension period is added to the predetermined time to extend the waiting period.
If at least one of the density of packages and the number relationship between the density of packages and the maximum number of packages in the aforementioned stagnant supply conveyor is greater than a predetermined value,
(Process 2) After the predetermined waiting period has elapsed, the stopped cargo is moved in a circular motion on the circular conveyor.

The present invention's conveying device, when a branched load that should enter the supply conveyor corresponding to a branching point is held up at the branching point, and another load behind the branched load is held up due to being held up, will move the branched load to the circular conveyor after a predetermined time has elapsed. In other words, the branched load will be sent back around on the circular conveyor.

This allows stalled cargo, which was previously blocked by the diverted cargo, to move along the circular conveyor. If the stalled cargo is supplied to a conveyor other than the one corresponding to the diverted cargo, it can be diverted to the appropriate conveyor before the diverted cargo completes another full rotation.

This allows the stagnant cargo to move to the supply conveyor to which it is to be branched. Similarly, the branched cargo can also move to the supply conveyor to which it is to be branched by completing another loop of the circular conveyor.

As described above, even when delays occur during branching from the circular conveyor to the supply conveyor, the stopping time of the circular conveyor due to these delays can be reduced, thereby improving transport efficiency.

This is a plan view of a conveying system equipped with a circular conveyor and a branching conveyor. This schematic diagram illustrates a situation on a circular conveyor belt where some cargo stops at a branching point, and other cargo remains stationary behind the stopped cargo. This is a schematic diagram of a transport device according to an embodiment of the present invention. This is a schematic diagram showing a stagnation state in an embodiment of the present invention. This is a schematic diagram of a part of the conveying device in an embodiment of the present invention. This is a schematic diagram showing a stagnant supply conveyor in Embodiment 1 of the present invention.

The conveying device according to the first invention of the present invention includes a circular conveyor that circulates in accordance with multiple work areas and moves cargo in a circular manner,
The aforementioned circular conveyor includes multiple supply conveyors that move goods into the work areas from branching points corresponding to each of the multiple work areas,
A conveyor control unit that controls the circular movement of the aforementioned circular conveyor,
A supply conveyor control unit controls the storage movement on the supply conveyor,
A conveyor belt state detection unit for detecting the rotational state of the cargo on the aforementioned conveyor belt,
The system includes a stagnation control unit that controls the stagnation of circular movement at the aforementioned branching point,
The plurality of supply conveyors include a first supply conveyor, a second supply conveyor, ..., an Nth supply conveyor, corresponding to each of the plurality of work areas, which are the first work area, the second work area, ..., the Nth work area.
The aforementioned cargo includes one or more first cargo items of a type to be stored in the first work area, one or more second cargo items of a type to be stored in the second work area, ... one or more nth cargo items of a type to be stored in the N work area,
The multiple branching positions include the first branching position, the second branching position, ... the Nth branching position, corresponding to the first supply conveyor, the second supply conveyor, ... the Nth conveyor,
The aforementioned circular conveyor control unit is:
The first load is transferred to the first supply conveyor at the first branching position.
The second load is then transferred to the second supply conveyor at the second branching point, and...
The aforementioned N load is transferred to the N supply conveyor at the N branching position,
The aforementioned circular conveyor state detection unit is capable of detecting stopped cargo at any of the first to Nth branch positions and stagnant cargo stopped behind said stopped cargo.
If the stall control unit detects the stalled cargo, it will cause the stalled cargo to wait for a predetermined time at the branching position where it is stopped.
The stall control unit, based on at least one of the following, the number of packages in the "stalling supply conveyor" corresponding to the stopped packages, the density of the packages, the number relationship to the maximum number of packages, the position of the packages on the stalling supply conveyor, and the movement state of the stalling supply conveyor, determines the elapsed time of the predetermined waiting period.
(Process 1) The waiting period is extended by granting an extension time to the predetermined time, or
(Process 2) After the predetermined time has elapsed, the stopped load is moved in a circular motion on the circular conveyor.

This configuration allows for processing that considers overall transport efficiency, even when there are stopped or stagnant loads at the supply point, resulting in a stagnant state.

In the conveying device according to the second invention of this invention, in addition to the first invention, the stopped load is caused by the inability to move from the stopped branching position to the corresponding supply conveyor.

This configuration allows the system to switch between waiting or prioritizing the next shipment if branching off is not possible. As a result, overall transport efficiency can be increased.

In the conveying device according to the third invention of the present invention, in addition to the first or second invention, the supply conveyor has a first position, a second position, a third position, ..., and an Mth position from the branching position,
When there is a load at the first position, the stopped load occurs,
The stagnation control unit determines the predetermined time based on the degree to which the cargo is filled from the first position to the Mth position.

This configuration allows for the determination of a predetermined time that optimizes overall transport efficiency. This, in turn, optimizes the standby time.

In the fourth invention of the present invention, in addition to the third invention, the stagnation control unit determines the extension time based on the degree of occupancy of the cargo from the first position to the Mth position.

This configuration allows the extended time in process 1 to be considered within the overall efficiency framework.

In the transport device according to the fifth invention of this invention, in addition to the fourth invention, if the stagnation control unit can predict that the first position will become available, the extension time is set to the time until the first position becomes available.

This configuration increases the likelihood that stopped cargo can be redirected after extended waiting time, thus enhancing the efficiency benefits of waiting.

In the conveying device according to the sixth invention of this invention, in addition to any of the first to fifth inventions, the stagnation control unit grants the extension time if at least one of the density of packages in the stagnation supply conveyor and the number relationship with the upper limit number of packages is below a predetermined value.

This configuration enhances the benefits of extending the standby state by adding extra time.

In the conveying device according to the seventh invention of this invention, in addition to any of the first to fifth inventions, the stagnation control unit grants the extension time when there is a movement operation of the cargo on the stagnation supply conveyor.

This configuration enhances the benefits of extending the waiting time, as it increases the likelihood that the stopped cargo can be redirected.

In the eighth invention of the present invention, in addition to the first or second invention, the stagnation control unit moves the stopped loads in the circulating conveyor in a circular motion if at least one of the density of loads in the stagnation supply conveyor and the number relationship with the upper limit of the number of loads is greater than a predetermined value.

This configuration prioritizes the movement of stagnant cargo over prolonged standby, thereby increasing overall transport efficiency.

In the conveying device according to the ninth invention of this invention, in addition to the first or second invention, the stagnation control unit, when no cargo movement is occurring on the stagnation supply conveyor, causes the stopped cargo to circulate on the circulating conveyor.

This configuration prioritizes the movement of stagnant cargo over prolonged standby, thereby increasing overall transport efficiency.

In the conveying device according to the tenth invention of the present invention, in addition to the third invention, the stagnation control unit moves the stopped load in a circular motion on the circular conveyor when there is a load at at least at the first, second, and third positions among the first to M positions.

This configuration prioritizes processing the branching movement of stagnant cargo through circular movement rather than maintaining a standby state.

In the conveying device according to the eleventh invention of the present invention, in addition to any of the first to tenth inventions, the predetermined time is determined based on at least one of the following: the number of work areas, the storage capacity of the work areas, the number of items that can be moved on the supply conveyor, the movement capacity of the supply conveyor, the number of items that can be moved on the circulating conveyor, the movement capacity of the circulating conveyor, and the length of the circulating conveyor.

This configuration allows for a standby state that improves overall transport efficiency.

The conveying device according to the twelfth invention of this invention further includes, in addition to any of the first to eleventh inventions, a storage crane for storing the cargo that has reached the work area side of the supply conveyor into the work area.

This configuration ensures that goods moving along the supply conveyor are properly handed over to the next process.

In the conveying device according to the thirteenth invention of the present invention, in addition to any of the first to twelfth inventions, if it becomes possible to branch the stopped cargo to the stagnant supply conveyor before the predetermined time has elapsed, the stagnant control unit branches and moves the stopped cargo to the stagnant supply conveyor.

This configuration ensures that even in standby mode, if a branching movement is required, the stopped cargo will be moved to the branching point. This allows for the elimination of stagnation even during standby (within a predetermined time or extended time).

The embodiments of the present invention will be described below with reference to the drawings.

(Embodiment 1)

(Analysis by the inventor)
Figure 1 is a plan view of a conveying device equipped with a circular conveyor and a branching conveyor. Using Figure 1, the inventor's analysis of the problems with conventional conveying devices using circular conveyors and branching conveyors will be explained.

Figure 1 shows a top view of the conveying device 100. The conveying device 100 comprises a circular conveyor 110 and multiple supply conveyors 120. Each of the supply conveyors 120 is connected to a storage compartment for storing goods.

The conveying device 100 is equipped with a circulating conveyor 110 in the center for moving goods in a circular path. The circulating conveyor 110 has multiple branching points 111, and supply conveyors 120 for moving goods to storage compartments are connected to these branching points 111. That is, as shown in Figure 1, there is a circulating conveyor 110 with multiple supply conveyors 120 protruding from it. Each of the protruding supply conveyors 120 is connected to a storage compartment, facilitating the movement of goods for storage (and conversely, movement for retrieval from storage is also possible).

For example, when storing goods in a storage compartment, the following process is performed: The goods are placed into the input port of the circular conveyor 110. The storage compartment to which the goods will be stored is predetermined based on the type of goods. The control unit, which controls the entire conveying device 100, identifies the appropriate storage compartment for each item and performs the storage operation accordingly.

The loaded cargo moves in a circular motion along the circular conveyor belt 110. The circular conveyor belt 110 can move the cargo in a circular direction, allowing the cargo to move in a circular motion accordingly.

During this circular movement, the cargo reaches multiple branching points. Supply conveyors 120 are connected to these branching points. For example, the first supply conveyor is connected to the first branching point, the second supply conveyor to the second branching point, and the nth supply conveyor to the nth branching point. For instance, cargo A is stored in the first storage unit via the first supply conveyor. Another cargo B is stored in the second storage unit via the second supply conveyor.

Therefore, when cargo A reaches the first branching point, it branches off here and moves from the circular conveyor to the first supply conveyor. When cargo B reaches the second branching point, it branches off here and moves from the circular conveyor to the second supply conveyor. Once on the first supply conveyor, cargo A is moved towards the first storage unit by the first supply conveyor. Through this storage movement, cargo A is stored in the first storage unit. Similarly, cargo B moves along the second supply conveyor and is stored in the second storage unit.

The same applies to the other luggage.

Multiple packages move randomly in a circular motion along the circular conveyor belt 110. Each of the packages moves to its corresponding storage unit. Therefore, they branch off at the corresponding branching points and move to the corresponding supply conveyor belt 120.

If the supply conveyor 120 is not congested, the cargo moving in a circular motion on the circulating conveyor 110 will successively branch off at the corresponding branching points and move to the corresponding supply conveyor 120.

However, it is possible that one of the multiple supply conveyors 120 may become congested. For example, if the first supply conveyor 120 becomes congested, the cargo that should enter the first supply conveyor may stop at the first branching point without being able to branch off. On the circular conveyor 110, cargo moves in a continuous loop. Therefore, as long as there is cargo stopped at the first branching point, cargo moving along the circular conveyor from behind will be held up behind the cargo stopped at the first branching point. This is because the stopped cargo obstructs further movement along the circular conveyor 110.

Figure 2 is a schematic diagram illustrating a situation on this circular conveyor where there are stopped loads at a branching point and stagnant loads behind these stopped loads. The first supply conveyor 120A is congested. Load A, which should be moving onto the first supply conveyor 120A, is stopped at the first branching point. It is unable to enter the first supply conveyor 120A and remains in a stopped load state.

Behind the stopped cargo A, cargo B, which has been moving along the circular conveyor 110, is also stalled. Cargo B is cargo that is moving from a different branching point to a different supply conveyor. Although cargo B needs to move further, it remains stalled before the first stopping point of the circular conveyor 110. In other words, cargo B is stalled cargo.

The stopped cargo A and the stalled cargo B are stuck on the circular conveyor belt 110.

Therefore, in the conventional conveying device 100, the circular movement of cargo B on the circular conveyor 110 remains stalled until the congestion on the first supply conveyor 110A is resolved (the congestion ends when the cargo on the first supply conveyor 110A moves to the first storage area). If the congestion on the first supply conveyor 110A is not resolved, cargo B cannot reach its intended storage location.

In other words, the overall efficiency of cargo storage in the conveying device 100 decreases. This is a problem with the conventional technology, and the inventor arrived at the present invention based on this analysis.

(Embodiment)

(Overall overview)
In the following, a storage room will be used as an example of a work area. A work area can include equipment for light work or equipment that connects to the next process, in addition to the storage room. While a storage room is used as an example in the following explanation, it is merely one example of a work area and is not limited to storage rooms.

Figure 3 is a schematic diagram of a conveying device in an embodiment of the present invention. It shows the conveying device 1 viewed from above. The conveying device 1 performs conveying to store goods 200 in one of a plurality of storage compartments 10, or to retrieve goods 200 from one of the plurality of storage compartments 10 and deliver them. The storage compartment 10 to which the goods 200 to be conveyed by the conveying device 1 will be stored is predetermined. The storage compartment 10 to which the goods 200 should be stored is determined by the type and category of the goods 200. As mentioned above, even in the case of work equipment, the work area to which the goods 200 should be moved is predetermined.

Therefore, the transport device 1 is designed to accommodate multiple storage compartments 10.

The conveying device 1 comprises a circulating conveyor 2, multiple supply conveyors 3, a circulating conveyor control unit 21, a supply conveyor control unit 31, a circulating conveyor state detection unit 6, and a stagnation control unit 7. Although the circulating conveyor control unit 21, supply conveyor control unit 31, circulating conveyor state detection unit 6, and stagnation control unit 7 are not visible in Figure 3, they are present in the conveying device 1. For example, they may be incorporated into one of the mechanical parts of the conveying device 1, or into the control device or operating device of the conveying device 1.

Furthermore, the circulating conveyor control unit 21, the supply conveyor control unit 31, the circulating conveyor state detection unit 6, and the stagnation control unit 7 may be implemented through a combination of electronic, mechanical, and software programs.

The circular conveyor 2 has a configuration that circulates in accordance with multiple storage compartments 10, and moves the cargo 200 in a circular manner. As shown in Figure 3, the circular conveyor 2 has a configuration that circulates in accordance with multiple storage compartments 10 arranged around it. Therefore, its circular shape and size are determined by the number and position of the storage compartments 10.

The circular conveyor belt 2 is equipped with an input port 51 and an output port 52. The cargo 200 is fed into the circular conveyor belt 2 from the input port 51. The fed cargo 200 then travels along the circular conveyor belt 2. During its journey, it branches off to the supply conveyor belt 3 and is stored in the storage unit 10.

At the input port 51 and output port 52, equipment such as forklifts may be used to load and unload the cargo 200. Work can be performed by an operator or through automated operation, resulting in the cargo 200 being loaded from the input port 51 onto the circulating conveyor 2 and unloaded from the output port 52.

Conversely, the cargo 200 removed from storage 10 moves from supply conveyor 3 to circulating conveyor 2. After circling circulating conveyor 2, it is discharged from discharge port 52. The discharged cargo 200 is then handed over to another process.

The circular conveyor belt 2 moves the cargo 200 in a circular path, facilitating its storage in designated storage units 10 and its unloading from storage units 10.

The circular conveyor control unit 21 controls the circular movement of the circular conveyor 2. It controls the circular movement of the cargo 200, and also controls the movement of stopped or stagnant cargo (as described later) by stopping them. It also controls the speed of circular movement. Furthermore, it can control the resumption of circular movement of stopped cargo after a predetermined time has elapsed by the stagnation control unit 7.

Multiple supply conveyors 3 branch off and connect to the circular conveyor 2. The branching points are designated as branching points 4. That is, branching points 4 are located at multiple locations along the circular conveyor 2, and supply conveyors 3 are connected from each of these branching points 4. Since the supply conveyors 3 correspond to the storage units 10, the number and locations of the supply conveyors 3 correspond to the number and locations of the storage units 10.

In Figure 3, since the storage unit 10 is located outside the circular conveyor 2, the multiple supply conveyors 3 protrude outwards from the circular conveyor 2 like corners. If the storage unit 10 were located inside the circular conveyor 2, the multiple supply conveyors 3 would protrude inwards from the circular conveyor 2.

The branching point 4 branches off the cargo 200 that has been circulating on the circular conveyor 2 to the supply conveyor 3. The supply conveyor 3 then moves the incoming cargo 200 into the storage unit 10. Of course, when the cargo is unloaded from the storage unit 10, it is moved back towards the circular conveyor 2. The intention is not to limit it to either one or the other.

While the circular conveyor 2 moves the cargo 200 in a circular motion, the supply conveyor 3 moves the cargo 200 in a linear motion (not necessarily a perfectly straight line, but a linear movement). The supply conveyor 3 moves the cargo 200 in a storage manner, and the cargo 200 that reaches the storage unit 10 is stored in the storage unit 10.

The supply conveyor control unit 31 controls the storage movement of the cargo 200 on the supply conveyor 3. It moves the cargo 200, which has entered from the branching point 4, toward the storage compartment 10. It also waits for the cargo to be ready for storage in the storage compartment 10 before proceeding with the storage movement. This ensures smooth and reliable storage (the same applies to unloading).

The cargo 200 to be stored in the first storage compartment 10A is the first cargo 200A. The cargo 200 to be stored in the second storage compartment 10B is the second cargo 200B. The cargo 200 to be stored in the nth storage compartment 10N is the nth cargo 200N (in Figure 3, only the first storage compartment 10A, etc., are shown as symbols). Note that there may be multiple first cargo 200A, etc. Essentially, it is the cargo that should go into the first storage compartment 10A.

Thus, corresponding to the first storage unit 10A to the nth storage unit 10N, the branching position 4 also includes the first branching position 4A, the second branching position 4B, ... the nth branching position 4N, and the supply conveyor 3 also includes the first supply conveyor 3A, the second supply conveyor 3B, ... the nth supply conveyor 3N. The first, second, ..., nth indicate the corresponding relationships in the storage unit 10, the supply conveyor 3, and the branching position 4, respectively.

The circulating conveyor control unit 21 branches off the corresponding cargo 200 at branching position 4 to the supply conveyor 3. At this time, the first cargo 200A, which should be stored in the first storage unit 10A, is branched off to the first supply conveyor 3A at the first branching position 4A. The second cargo 200B, which should be stored in the second storage unit 10B, is branched off to the second supply conveyor 3B at the second branching position 4B. ... The nth cargo 200N, which should be stored in the nth storage unit 10N, is branched off to the nth supply conveyor 3N at the nth branching position 4N.

Through branching control by the circular conveyor control unit 6, each of the 200 packages moves to the storage unit 10 where it is to be stored (via the circular conveyor 2 and the supply conveyor 3).

The circulating conveyor control unit 21 and the supply conveyor control unit 31, as shown in Figure 3, are provided as a control panel, and control can be performed within this control panel. Alternatively, the circulating conveyor control unit 21 and the supply conveyor 31 can be controlled by an operator operating the control panel.

Here, as shown in Figure 4, there are cases where a load stops at branching point 4 because it cannot enter the supply conveyor 3, which it should enter, due to congestion. Furthermore, this stopped load can block the circular conveyor 2, potentially causing other loads coming from behind to become stagnant loads that cannot proceed further. Figure 4 is a schematic diagram illustrating a stagnant state in an embodiment of the present invention.

The conveyor state detection unit 6 detects this stagnant state. The supply conveyor 3 in this stagnant state is a stagnant supply conveyor.

In Figure 4, cargo A is cargo that should enter the first supply conveyor 3A from the first branching point 4A. The first supply conveyor 3A is congested with cargo destined for storage in the first storage unit 10A. Therefore, cargo A cannot branch off from the first branching point 4A. Consequently, cargo A is stopped at the first branching point 4A. In other words, cargo A is stopped cargo.

The presence of this stopped cargo prevents the next cargo B, which has been traveling along the circular conveyor belt 2, from moving any further. Cargo B becomes a stagnant cargo behind the stopped cargo. In Figure 4, cargo B is shown as a stagnant cargo. Of course, if cargo 200 continues to travel along the circular conveyor belt 2, another cargo 200 may reach behind cargo B, potentially increasing the number of stagnant cargoes.

The conveyor state detection unit 6 detects this state, where both stopped and stagnant cargo exist, as a stagnant state. In other words, the conveyor state detection unit 6 detects stagnant cargo. This is because if stagnant cargo exists, stopped cargo also exists, resulting in a stagnant state.

The conveyor status detection unit 6 notifies the stagnation control unit 7 of this detection result.

If the stagnant cargo control unit 7 detects stagnant cargo (i.e., if a stagnant state is detected), it first performs the following prerequisite processing.

(Prerequisite Processing) At branching point 4 where the stopped cargo is stopped, it is made to wait for a predetermined time (in Figure 4, cargo A is made to wait at the first branching point 4A).

When a congestion occurs, cargo A cannot enter supply conveyor 3A from branching point 4A. Cargo A cannot enter supply conveyor 3A until the congestion on supply conveyor 3A, which is currently congested, is resolved and it becomes possible for cargo A to enter.

Therefore, as a prerequisite, the congestion control unit 7 places the stopped cargo A and the stagnant cargo B on standby for a predetermined time. This is performed as a prerequisite. If, during the predetermined waiting period, the congestion on the supply conveyor 3A decreases and cargo A becomes capable of branching off, the congestion control unit 7 moves the stopped cargo off the conveyor.

However, there is a possibility that branching movement may not become possible within the predetermined time. Furthermore, there may be uncertainties regarding how long it will take for branching movement to become possible, or even if it will not at all. Therefore, keeping stopped cargo waiting for extended periods will prevent the stagnant cargo from moving from branching point 4A, reducing the overall transport efficiency of the transport device 1.

Therefore, in the event of a stagnant situation where there is a backlog of cargo, the stopped cargo may be sent ahead by the circular conveyor 2, and the backlogged cargo that was stopped behind the stopped cargo may be moved forward by the circular conveyor 2. This means that the stopped cargo would need to travel around the circular conveyor 2 once to reach its original branching point 4A, while the backlogged cargo can proceed along the circular conveyor 2 to reach its intended branching point.

However, in the latter case, the congestion on the stalled supply conveyor may clear immediately after the stopped cargo begins circulating on the circular conveyor 2, allowing the stopped cargo to branch off from branching point 4A to supply conveyor 4A. Therefore, immediately resolving the waiting state and resuming the circulation of the stopped cargo on the circular conveyor may not be desirable from an overall efficiency standpoint.

Based on these premises, in the conveying device 1 of the present invention, the stagnation control unit performs the following processing after the waiting processing of the stopped cargo for a predetermined time in the prerequisite processing.

The stagnation control unit 7, based on at least one of the following factors—the number of packages 200 on the "stagnation supply conveyor" (supply conveyor 3A in Figure 4), which corresponds to the stopped packages; the density of the packages 200; the relationship between the actual number of packages 200 and the upper limit; the position of the packages 200 on the stagnation supply conveyor; and the movement state of the stagnation supply conveyor—makes the following decisions regarding the elapsed time:

(Process 1) The standby state is extended by granting an extension time to the predetermined time.
or,
(Process 2) After a predetermined time has elapsed, the stopped cargo 200 is moved in a circular motion on the circular conveyor 2.
Execute the following process.

The stagnation control unit 7 selects and executes either process 1 or process 2 based on the state of the stagnant supply conveyor. The stopped cargo (cargo A in Figure 4) occurs when the cargo cannot branch off from the stopped branching point 4A to the corresponding supply conveyor 3A. This results in stagnant cargo.

Therefore, during the predetermined waiting period, if the congestion level (density, number of items, etc.) on the stalled supply conveyor is low, or if the movement conditions are favorable, the stalled control unit 7 will extend the waiting time by granting an extension. This is because there is a high probability that the congestion on the stalled supply conveyor 3A will eventually be resolved, making it possible to branch off and move the stopped cargo from branching point 4A. In this situation, prioritizing branching off and moving the stopped cargo, even if it means keeping the stagnant cargo on standby, is more efficient for the entire conveying system 1 than moving the stopped cargo back around on the circular conveyor 2. If branching becomes possible within the extended time, the stopped cargo will be branched off and moved to the supply conveyor 3.

Conversely, if the density of cargo on the stagnant supply conveyor 3A is high, or if its movement remains stopped, the stagnation control unit 7 will, after a predetermined time has elapsed, move the stopped cargo in a circular motion on the circular conveyor 2. In other words, it will transition the stopped cargo to circular motion. This is because it is determined that even if an extended waiting time is granted, the congestion on the stagnant supply conveyor 3A will not be resolved, and the overall transport efficiency of the transport device 1 will decrease.

In this case, priority is given to transitioning to circular movement, moving the stagnant cargo behind the stopped cargo to the appropriate branching point 4. This causes the stagnant cargo to branch off onto the supply conveyor 3 and be stored in the storage unit 10 (of course, it will then be used for work in other intended work areas besides the storage unit 10).

The stopped cargo, after being transferred to the circular conveyor belt 2, completes another circuit and returns to the corresponding branching point 4, where it can then branch off to the supply conveyor belt 3. If the cargo becomes stopped again at the branching point 4 upon its return, the same process is executed by the stagnation control unit 7.

In this way, even in the case of process 2, the overall transport efficiency of the transport device 1 can be increased.

Thus, when a stagnation state occurs (a state where stagnant cargo is generated following a stopped cargo), the stagnation control unit 7 performs prerequisite processing and then selectively executes either process 1 or process 2. Of course, if the stagnation supply conveyor 3A becomes capable of accepting branch movement during this time, the stopped cargo will branch off and move, even if it is within the predetermined time.

This control system improves the overall transport efficiency of the transport device 1, which consists of the circulating conveyor 2 and the supply conveyor 3.

Next, we will explain the details and variations of each part.

(Stopped cargo and delayed cargo)
As shown in Figure 4, cargo A is a stopped cargo. A stopped cargo occurs when it is unable to branch off from the branching point 4 where it is stopped to the corresponding supply conveyor 3. This can happen, for example, when the supply conveyor 3 is congested, as shown in Figure 4, preventing the cargo from branching off and entering the conveyor.

Figure 5 is a schematic diagram of a part of a conveying device in an embodiment of the present invention. The conveying device 1 in Figure 5 further includes a supply conveyor state detection unit 33. The supply conveyor state detection unit 33 detects at least one of the movement state of the cargo 200 on the supply conveyor 3 and the quantity limit state. The movement state is the state of movement of the cargo 200 toward the storage unit 10 on the supply conveyor 3. The quantity limit state is the upper limit of the number of items that can be stored on the supply conveyor 3. Since the supply conveyor 3 also moves the cargo 200, there is an upper limit to the number of items that can be moved. The state relative to this upper limit is called the quantity limit state.

The supply conveyor status detection unit 33 detects an abnormal condition in the supply conveyor 3 (an abnormality where branch movement from branch position 4 is not possible). This abnormal condition indicates a state where branch movement cannot be accepted.

Firstly, the supply conveyor status detection unit 33 determines that branching movement is impossible if the movement status on the supply conveyor 3 is abnormal. For example, this occurs when the supply conveyor 3 is blocked due to congestion or malfunction, preventing the cargo 200 from moving towards the storage unit 10. Alternatively, it determines that an abnormal state exists when the cargo 200 at the position immediately following the branching point 4 of the supply conveyor 3 fails to move.

Another factor is when the number of packages on the supply conveyor 3 reaches its maximum capacity; in such cases, the system determines that branching is not possible. If the number of packages 200 on the supply conveyor 3 reaches its maximum capacity, the next package 200 cannot enter. In this case, the supply conveyor status detection unit 33 also determines that branching is not possible.

Based on this assessment, cargo 200, which cannot be moved to a branch line, will be designated as a stopped cargo.

This occurrence of stopped cargo results in a backlog of cargo at the rear of the circular conveyor belt 2. This backlog may be cargo 200 entering from the branching point 4 where the stopped cargo is located, or it may be cargo 200 entering from a branching point 4 further along the conveyor belt.

During the standby period (for a predetermined time or extended time), if branching to the stagnant supply conveyor 3A becomes possible, the stagnant control unit 7 will branch off and move the stopped cargo. As a result, the stopped cargo will branch off and be stored on the supply conveyor 3 to which it should enter.

In addition, the stagnant cargo that was held up behind the stopped cargo will move on to circular conveyor belt 2 and reach its designated branching point 4. Upon reaching this point, it will branch off from branching point 4 to supply conveyor belt 3. At this time, if branching conveyor belt 3 is congested, the stagnant cargo that has moved may become stopped cargo itself.

(Prerequisite processing and prescribed time)
If a stagnant state occurs, the stagnant control unit 7 puts the stopped cargo into a waiting state for a predetermined time (the prerequisite processing described above). This is to make the cargo wait until it is possible to move from the branching position 4 to the branching conveyor 3, and then move it when possible. As for the processing after the predetermined time has elapsed, as described above, either process 1 or process 2 is performed depending on the state of the stagnant supply conveyor.

The predetermined time in this prerequisite processing can be determined by the stagnant state of the stagnant supply conveyor 3. Figure 6 is a schematic diagram showing the stagnant supply conveyor in Embodiment 1 of the present invention.

The supply conveyor 3 has a branching point 4, followed by a first position, a second position, ... up to the Mth position. The load 200 moves through each of these positions. Sometimes, the load 200 is at the first position and has not yet moved to the second position. Therefore, this supply conveyor 3 functions as a stagnant supply conveyor 3A.

In this state, cargo 200 arrives at branching point 4A. This cargo 200 should be moved from branching point 4A to the stationary supply conveyor 3A. However, it cannot be moved. Furthermore, cargo 200 that arrives behind the stationary cargo 200A becomes a stagnant cargo.

The stagnation control unit 7 places the stopped cargo 200A into a waiting state for a predetermined time. At this time, the predetermined time can be determined by the degree to which the cargo 200 is filled on the stagnation supply conveyor 3A. Specifically, the predetermined time is determined by the degree to which the cargo 200 is filled from the first position to the Mth position. This is because the time until branch movement to the stagnation supply conveyor 3A becomes possible can be predicted based on the degree of filling.

If the congestion level is high, priority will be given to extending the predetermined time so that the stopped cargo 200A can branch off and move from branching point 4A. Alternatively, if the congestion level is so high that extending the predetermined time would reduce overall transport efficiency, the predetermined time may be shortened.

Even when the occupancy rate is low, the same approach should be used to determine the required time.

The predetermined time is preferably determined considering the overall transport efficiency of the transport device 1. For example, the predetermined time can be determined based on at least one of the following: the number of storage compartments 10, the storage capacity of the storage compartments 10, the number of loads 200 that can be moved on the supply conveyor 3, the transport capacity of the supply conveyor 3, the number of loads 200 that can be moved on the circulating conveyor 2, the transport capacity of the circulating conveyor 2, and the length of the circulating conveyor 2.

By basing this on at least one of these factors, a predetermined time corresponding to the overall transport efficiency of the transport device 1 can be achieved.

For example, if the number of storage units 10 and their storage capacity are high, even if stopped cargo occurs, branching to the supply conveyor 3 becomes easier. Therefore, even if the predetermined time is set to a certain length, branching to the stopped cargo is likely to be possible during that time. Conversely, if the number of storage units 10 and their storage capacity are low, branching to the conveyor will not be possible easily, even if the predetermined time is extended. It is preferable to shorten the predetermined time and move the cargo to the circulating conveyor 2 earlier.

Conversely, if storage capacity is high, the predetermined time can be shortened to facilitate transitions to branching movement, and the predetermined time can be set accordingly.

This method also applies when using the capacity of the supply conveyor 3 or the circulating conveyor 2 as a basis; the same predetermined time should be set.

The predetermined time may be variable. This means that the predetermined time set may differ each time a transport operation is performed by the transport device 1, or the predetermined time may be changed while the transport operation is in progress.

In the former case, for example, if the total number of packages 200 to be stored is large during a certain transport routine, a predetermined time is set to a certain duration. When switching to a different transport routine, if the total number of packages 200 decreases, the predetermined time is adjusted accordingly.

In the latter case, the predetermined time is changed within a single transport operation routine.

For example, the stagnation control unit 7 can change the predetermined time based on the number of stagnant items lingering behind the stopped item. If there are many stagnant items, the predetermined time is shortened to prioritize moving the stagnant items on the circular conveyor 2 to their respective branching points 4, rather than waiting for the stopped items to branch off to the supply conveyor 3.

Conversely, if the number of stalled packages is small, the predetermined time is extended to allow the stalled packages to branch off and move to the supply conveyor 3. This is because it is more efficient overall.

Thus, varying the predetermined time (the waiting time for stopped packages) based on the number of packages held is also suitable for improving overall efficiency.

(Process 1 and extension time)
The stagnation control unit 7 determines either process 1 or process 2 based on at least one of the following: the number of packages 200 on the stagnation supply conveyor 3A, the density of the packages 200, the number relationship with the upper limit of the number of packages 200, the position of the packages 200 on the stagnation supply conveyor 3A, and the movement state of the stagnation supply conveyor 3A.

If, based on the stagnation at the stagnant supply conveyor 3A, it is determined that further delaying the stopped cargo 200A would allow for a transition to branching movement, then the process proceeds to step 1. Conversely, if it is determined that the delay would be too long and reduce the overall transport efficiency, the process proceeds to step 2.

The stagnation control unit 7, if at least one of the density of the cargo 200 on the stagnation supply conveyor 3A and the relationship between the upper limit number and the number of items is below a predetermined value, proceeds to process 1 and grants an extension time. This is because, if the value is below the predetermined value, extending the waiting time by the extension time makes it highly likely that the stopped cargo 200A will be able to branch off and move. Waiting for branching movement increases overall transport efficiency.

Alternatively, if movement of the cargo 200 occurs on the stalled supply conveyor 3A, the stall control unit 7 grants an extension time and proceeds to process 1. Even if the stalled supply conveyor 3A is congested, if movement occurs, there is a high probability that a vacancy will become available at the first position, making it efficient to grant an extension time and wait for branch movement.

The stagnation control unit 7 may also determine the extension time based on the degree to which the cargo 200 is filled from the first position to the Mth position. The extension time can also be determined by the degree to which the cargo 200 is filled from the first position to the Mth position on the stagnation supply conveyor 3A. The length of the extension time can be determined using the same method as for the predetermined time.

Furthermore, if the stagnation control unit 7 predicts that the first position of the stagnation supply conveyor 3A will become available, it sets the time until the first position becomes available as an extension time. This allows the system to remain in a waiting state for the extended time, even if the stagnation supply conveyor 3A remains congested, as long as the stopped cargo 200A is in a state where it can branch off and move.

Furthermore, the stagnation control unit 7 can also increase or decrease the extension time. By increasing or decreasing the extension time in accordance with the change in the state of the stagnation supply conveyor 3A, it is possible to switch between waiting for the stopped cargo 200A to branch off from state 1, or changing to state 2 before waiting for the branching movement. This can improve the overall transport efficiency.

(Process 2 and circular movement)
The stagnation control unit 7 may also initiate process 2 based on the state of the stagnation supply conveyor 3A. This may be done by transitioning to process 2 after a predetermined time has elapsed, or by transitioning to process 2 during the extended time of process 1. The state of the stagnation supply conveyor 3A is such as the density of the cargo 200 on the stagnation supply conveyor 3A as described above.

The congestion control unit 7 determines that if the congestion on the stalled supply conveyor 3A does not appear to be clearing when the predetermined waiting time is up, further delaying the stopped cargo 200A would reduce overall efficiency. In this case, the stopped cargo 200A is switched to circular movement, prioritizing the circular movement of the stagnant cargo 200B located downstream and the branching movement at branching point 4. This is because it improves overall transport efficiency. In particular, if the stopped cargo 200A remains stopped at branching point 4A indefinitely, the number of stagnant cargo downstream will increase.

Such increases are undesirable because they complicate the stagnation.

Therefore, the stagnation control unit 7 proceeds to process 2. This is because, upon transitioning to process 2, the stopped cargo 200A moves around the circular conveyor 2, allowing the subsequent stagnant cargo 200B to reach its branching position 4. Furthermore, the stagnation control unit 7 may also initiate this transition to process 2 before the extended time in process 1 has elapsed.

The stagnation control unit 7 proceeds to process 2 if at least one of the following is greater than a predetermined value: the density of the packages 200 on the stagnation supply conveyor 3A, or the relationship between the upper limit number of packages 200 and the actual number of packages 200. That is, the stopped packages 200A are moved in a circular motion on the circular conveyor 2.

In this situation, it takes a considerable amount of time to resolve the standby state (to reach the branching point). Prioritizing the movement of the stagnant cargo 200B to branching point 4 and the subsequent branching movement is more efficient overall than continuing the standby state.

The stopped cargo 200A transitions to circular movement, completing another lap around the circular conveyor 2. During this time, the lingering cargo 200B can reach the branching point 4 where it should branch off. The branching movement from this branching point 4 then takes place. This allows the lingering cargo 200B to be moved from the supply conveyor 3 to the storage area 10 (work area). Note that the storage movement refers to movement to the work area and is not intended to be limited to storage in the storage area 10.

Alternatively, if no cargo movement is occurring on the stalled supply conveyor 3A, the stall control unit 7 will proceed to process 2, causing the stopped cargo 200A to move in a circular path. This is because, when no cargo movement is occurring, prioritizing the branching movement of the stalled cargo 200B is more advantageous than granting or waiting for the extension time to end.

Alternatively, the stagnation control unit 7 may, if there are packages 200 at at least the 1st, 2nd, and 3rd positions among the 1st to Mth positions, proceed to process 2 and move the stopped packages 200A in a circular motion. For example, if there are packages 200 from the 1st to the 3rd positions, it may be difficult to resolve the congestion on the stagnation supply conveyor 3A. In such cases, it is better to move the stopped packages 200A in a circular motion to allow the stagnant packages 200B to reach the branching position 4, rather than continuing the waiting state.

Of course, you could also judge based on the occupancy rate of all 200 items, including those in positions 4 and beyond, rather than just positions 1 through 3, or you could judge based on the density of all 200 items.

If the stagnation control unit 7 determines that it will take too long for the stopped cargo 200A to branch off and reduce the overall transport efficiency, it proceeds to process 2, causing the stopped cargo 200A to move in a circular path. This increases the overall transport efficiency.

Furthermore, the stagnation control unit 7 may also select whether to perform process 1 or process 2 based on criteria including the number of stagnant packages 200B. If the number of stagnant packages 200B is large, it is also beneficial overall to switch to process 2 and prioritize the movement of the stagnant packages 200B.

As described above, the stagnation control unit 7 may also switch to process 2 for overall efficiency. It may also control the system by selecting between process 1 and process 2, and even during the extended time of process 1, it may switch to process 2 depending on the situation. Of course, once a state where branching movement is possible is reached, the stopped cargo 200A is branched to resolve the stagnation.

(Transportation to storage area via supply conveyor)
The supply conveyor 3 moves the goods 200 into the storage unit 10 for storage. This storage and movement allows the goods that enter the supply conveyor 3 to be stored in the storage unit 10. Of course, it also takes out the goods 200 from the storage unit 10 and transports them out.

The supply conveyor control unit 31 controls the storage movement of the supply conveyor 3. When cargo 200 enters the supply conveyor 3 from the branching position 4, the control unit controls the storage movement of the supply conveyor 3 to move it to the storage unit 10.

Furthermore, it is preferable to further provide a storage crane 8 for storing the cargo 200 that has reached the storage compartment 10 side of the supply conveyor 3 into the storage compartment 10. Figure 3 shows the storage crane 8.

The storage crane 8 facilitates the transfer of goods 200 to and from the storage unit 10. When storing goods in the storage unit 10, the goods 200 are retrieved from the supply conveyor 3 and placed in the storage unit 10. The crane also retrieves goods from the storage unit 10 and transfers them back to the supply conveyor 3.

The supply conveyor 3 moves the cargo 200 in succession, storing the cargo 200 that entered from branching point 4 into storage unit 10. If the supply conveyor 3 becomes full before this storage can keep up, stopped cargo and stagnant cargo will occur.

The conveying device 1 of the present invention controls this stagnant state while considering the overall conveying efficiency. As described above, the conveying device 1 of the present invention can address stagnant states while increasing the overall conveying efficiency.

As mentioned above, storage area 10 is just one example of a work area and includes other work processes, etc.

The conveying apparatus described in the embodiments is merely an example illustrating the spirit of the present invention, and may include modifications and alterations that do not depart from the spirit of the invention.

The conveying apparatus described in the embodiments is merely an example illustrating the spirit of the present invention, and may include modifications and alterations that do not depart from the spirit of the invention.

1. Conveying device 2. Circular conveyor 3. Supply conveyor 4. Branching point 51. Input port 52. Output port 6. Circular conveyor status detection unit 7. Stagnation control unit 8. Storage crane 10. Storage area 200. Cargo

Claims (8)

A circular conveyor that moves around to accommodate multiple work areas and moves goods in a circular motion,
The aforementioned circular conveyor includes multiple supply conveyors that move goods into the work areas from branching points corresponding to each of the multiple work areas,
A conveyor control unit that controls the circular movement of the aforementioned circular conveyor,
A supply conveyor control unit controls the storage movement on the supply conveyor,
A conveyor belt state detection unit for detecting the rotational state of the cargo on the aforementioned conveyor belt,
The system includes a stagnation control unit that controls the stagnation of circular movement at the aforementioned branching point,
The plurality of supply conveyors include a first supply conveyor, a second supply conveyor, ..., an Nth supply conveyor, corresponding to each of the plurality of work areas, which are the first work area, the second work area, ..., the Nth work area.
The aforementioned cargo includes one or more first cargo items of a type to be stored in the first work area, one or more second cargo items of a type to be stored in the second work area, ... one or more nth cargo items of a type to be stored in the N work area,
The multiple branching positions include the first branching position, the second branching position, ... the Nth branching position, corresponding to the first supply conveyor, the second supply conveyor, ... the Nth conveyor,
The aforementioned circular conveyor control unit is:
The first load is transferred to the first supply conveyor at the first branching position.
The second load is then transferred to the second supply conveyor at the second branching point, and...
The aforementioned N load is transferred to the N supply conveyor at the N branching position,
The aforementioned circular conveyor state detection unit is capable of detecting stopped cargo at any of the first to Nth branch positions and stagnant cargo stopped behind said stopped cargo.
If the stall control unit detects the stalled cargo, it will cause the stalled cargo to wait for a predetermined time at the branching position where it is stopped.
The stagnation control unit, based on at least one of the following: the number of packages in the "stagnation supply conveyor," which is the supply conveyor corresponding to the stopped packages; the density of the packages; the number relationship with the upper limit of the number of packages; the position of the packages on the stagnation supply conveyor; and the movement state of the stagnation supply conveyor,
If at least one of the density of packages in the aforementioned stagnant supply conveyor and the number relationship between the density of packages and the maximum number of packages is less than or equal to a predetermined value,
(Process 1) In response to the elapsed waiting time of the predetermined time, an extension period is added to the predetermined time to extend the waiting period.
If at least one of the density of packages and the number relationship between the density of packages and the maximum number of packages in the aforementioned stagnant supply conveyor is greater than a predetermined value,
(Process 2) A conveying device that, after the predetermined waiting period has elapsed, moves the stopped cargo in a circular motion on the circular conveyor . The conveying device according to claim 1, wherein the stopped cargo is caused by the inability to move from the stopped branching position to the corresponding supply conveyor. The conveying device according to claim 1 , wherein the stagnation control unit determines the extension time based on at least one of the density of the cargo in the stagnation supply conveyor and the number relationship between the density of the cargo and the upper limit number of cargo items. The conveying device according to claim 1 , wherein the stagnation control unit grants the extension time when there is a movement of cargo on the stagnation supply conveyor. The conveying device according to claim 1 , wherein the stagnation control unit moves the stopped load in a circular motion on the circular conveyor when no load movement is occurring on the stagnation supply conveyor. The conveying device according to claim 1, wherein the predetermined time is determined based on at least one of the number of work areas, the storage capacity of the work areas, the number of items that can be moved on the supply conveyor, the mobility of the supply conveyor, the number of items that can be moved on the circulating conveyor, the mobility of the circulating conveyor, and the length of the circulating conveyor. The conveying device according to claim 1, further comprising a storage crane for storing the cargo that has reached the work area side of the supply conveyor into the work area. If it becomes possible to branch the stopped cargo to the stagnant supply conveyor before the predetermined time has elapsed, the stagnant control unit branches and moves the stopped cargo to the stagnant supply conveyor, according to any one of claims 1 to 7 .