Handling system

Abstract

This invention discloses a transport system including a track and a transport vehicle traveling on the track. The transport vehicle communicates with a control system. The track is divided into multiple track sections. When the control system receives a request from a transport vehicle to occupy a passage section, it determines whether the grid cell to be occupied by the request belongs to a track section. If so, the request is added to the corresponding request queue for authorization processing. If not, the request is divided into multiple sub-requests, and each sub-request is added to its corresponding request queue for authorization processing. The grid cell to be occupied by a sub-request is a grid cell within the same track section. This invention can process transport vehicle occupancy requests in parallel through multiple request queues, maximizing processing efficiency, reducing control system response time, improving the overall transport system efficiency, and promoting smoother transport vehicle operation.

Description

Technical Field

[0001] This invention relates to the field of automated handling equipment, and in particular to handling systems. Background Technology

[0002] Overhead transport systems (OHT systems) are important equipment in semiconductor manufacturing plants for handling materials such as wafer cassettes.

[0003] Patent document with publication number CN120057518A discloses a usable handling system.

[0004] In this system, the transport vehicle requests the right to occupy a passageway (exclusive passageway) with multiple grid cells from the control system based on its optimal path. The control system then determines whether to grant each transport vehicle the right to occupy the passageway it requests.

[0005] However, in large factories, the number of transport vehicles traveling on tracks can reach thousands, and each transport vehicle sends a place-occupying request every 1-2 seconds. This means that the control system will process thousands of requests per second on average, which greatly increases the response time of the control system. As a result, the transport vehicles need to decelerate and stop frequently during operation, which not only reduces the passage efficiency but also increases the vibration of materials and the wear of the transport vehicle wheels. Summary of the Invention

[0006] The purpose of this invention is to solve the above-mentioned problems existing in the prior art and to provide a material handling system.

[0007] The objective of this invention is achieved through the following technical solution: A transport system includes a track with a set of grid cells and a transport vehicle traveling on the track. The transport vehicle communicates with a control system. The track is divided into multiple track sections. When the control system receives a request from a transport vehicle to occupy a passage section including at least one grid cell, it determines whether the grid cell to be occupied by the request belongs to a track section. When it is determined that the grid cell to be occupied by the placeholder request belongs to a track partition, the placeholder request is added to the request queue corresponding to the track partition to which the grid cell to be occupied belongs for authorization processing. When it is determined that the grid cell to be occupied by the placeholder request belongs to multiple track partitions, the placeholder request is divided into multiple sub-requests, and each sub-request is added to the request queue corresponding to the track partition to which the grid cell to be occupied by the sub-request belongs for authorization processing. The grid cell to be occupied by a sub-request is the grid cell belonging to the same track partition among the grid cells to be occupied by the placeholder request.

[0008] Preferably, the control system employs multi-threading or multi-processing to process multiple request queues of request tasks in parallel.

[0009] Preferably, after dividing into multiple sub-requests, the order in which each sub-request is added to its corresponding request queue is determined according to the order in which the grid units to be occupied by each sub-request are allocated. When it is determined that the grid units to be occupied by a preceding sub-request have been authorized to the transport vehicle corresponding to the sub-request, the next sub-request after the preceding sub-request is added to its corresponding request queue.

[0010] Preferably, when a placeholder request is divided into more than 2 sub-requests, at least for the last sub-request, when the grid cells to be occupied by its previous sub-requests have been authorized to the transport vehicle corresponding to the sub-request, the last sub-request is added to the head of its corresponding request queue.

[0011] Preferably, when adding a placeholder request or sub-request to the request queue, the insertion position of the placeholder request or sub-request in the request queue is determined according to the priority of the transport task performed by the transport vehicle corresponding to the placeholder request or sub-request.

[0012] Preferably, when a transport vehicle corresponding to a placeholder request or sub-request has a transport task that needs to be processed first, the placeholder request or sub-request is added to the head of its corresponding request queue.

[0013] Preferably, when the control system plans a movement path for a transport vehicle, if the travel time of a feasible route is less than the travel time of other feasible routes and the difference in travel time does not exceed a first threshold, and if the feasible route simultaneously passes through a main route that connects the track zone where the starting point is located and other track zones except for the track zone where the destination to which the transport vehicle is to be moved is located, if the cross-regional traffic volume at the main route reaches a second threshold, then the feasible route is not selected; if the cross-regional traffic volume at the main route is less than the second threshold, then the feasible route is selected.

[0014] Preferably, when the transport vehicle moves to a predetermined position in a passageway, it sends a request to the control system to occupy the next passageway. If the transport vehicle continues to move to the deceleration position and still has not obtained the right to occupy the next passageway, the transport vehicle decelerates.

[0015] Preferably, during the deceleration process, the transport vehicle reduces its speed in stages or decelerates uniformly based on the distance between its current location and the end point of the currently occupied passageway.

[0016] Preferably, when a transport vehicle has a transport task that needs to be prioritized, the occupancy request sent by the transport vehicle to the control system includes all grid cells that its optimal path passes through.

[0017] The advantages of the technical solution of this invention are mainly reflected in: The material handling system of this invention divides the track into different track zones. When the control system receives a occupancy request from a material handling vehicle, it can add the occupancy request to the request queue of the different track zones according to the track zone to which the grid cell belongs, and then authorize the processing. This allows the material handling vehicle's occupancy request to be processed in parallel through multiple request queues, which can maximize processing efficiency, reduce the response time of the control system, improve the overall material handling efficiency of the system, facilitate smoother operation of the material handling vehicle, improve operational safety, and extend the service life of the material handling vehicle.

[0018] This invention adds sub-requests sequentially to their respective request queues, ensuring that the grid cells required by the previous sub-request are allocated to the transport vehicle before adding the next sub-request. This effectively prevents situations where grid cells required by a previous sub-request are not allocated to the transport vehicle, while grid cells required by a later sub-request are allocated, thus avoiding the situation where grid cells required by a later sub-request are invalidally occupied, affecting the use of other transport vehicles. This ensures the rationality of grid cell allocation.

[0019] When a placeholder request occupies a grid cell belonging to multiple grid partitions, the present invention adds the last sub-request to the head of the corresponding request queue. This effectively ensures that the sub-request is processed as quickly as possible, thereby enabling a placeholder request to be processed in a timely manner and improving the utilization efficiency of authorized grid cells.

[0020] This invention determines the position of a placeholder request or sub-request in its respective request queue based on the priority of the handling task. This allows the authorization corresponding to a high-priority handling task to be processed first, thereby ensuring that the high-priority handling task can be executed as soon as possible, which is beneficial to ensuring processing efficiency. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of a track according to the present invention; Figure 2 yes Figure 1 A diagram showing the track divided into three track zones; Figure 3 yes Figure 1 A schematic diagram showing the division of the track into four track zones; Figure 4 yes Figure 1Another diagram showing the division of the track into four track zones; Figure 5 This is a flowchart of the control system of the present invention processing a placeholder request; Figure 6 This is a schematic diagram of the track being divided into two track sections according to the present invention; Figure 7 This is a schematic diagram illustrating the planning of two feasible routes for a transport vehicle in this invention; Figure 8 This is a schematic diagram illustrating the request for subsequent passage sections and deceleration processing of the transport vehicle of the present invention during operation. Detailed Implementation

[0022] The objectives, advantages, and features of this invention will be illustrated and explained through the following non-limiting description of preferred embodiments. These embodiments are merely typical examples of applying the technical solutions of this invention, and all technical solutions formed by equivalent substitutions or equivalent transformations fall within the scope of protection claimed by this invention.

[0023] In the description of the solution, it should be noted that the terms "center," "upper," "lower," "left," "right," "front," "rear," "vertical," "horizontal," "inner," and "outer," etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the accompanying drawings and are only for the convenience and simplification of description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0024] Example 1 The following description, in conjunction with the accompanying drawings, illustrates the transport system disclosed in this invention, which includes a track having a set of grid cells and a transport vehicle traveling on the track. The transport vehicle communicates with the control system. The specific structures of the track and the transport vehicle can be referred to in the patent documents cited in the background section, and will not be elaborated here.

[0025] Similar to the patent documents cited in the background section, the control system also includes a transportation control system and a blockade control system. The transportation control system receives work tasks, determines the transport vehicles performing various tasks, plans movement paths for the transport vehicles, and instructs each transport vehicle to perform its work tasks according to the planned paths. These work tasks include, but are not limited to, transport tasks, scheduling tasks, and unlocking tasks. The blockade control system is used for authorization management and status management of each grid cell.

[0026] Unlike existing technologies, this invention divides the track into multiple track zones. The specific number and division principles of these zones depend on the characteristics of the grid track layout and the distribution of processing and buffering equipment beneath the track. Typically, the track sections with frequent transport vehicle movement are grouped into one track zone, while the connecting sections between these zones usually have lower usage rates and can be used as connecting areas. For example, for the attached... Figure 1 The track shown can be divided into the following sections: Figure 2 The track is divided into track partitions A, B, and C as shown; or the track can be divided into the following sections: Figure 3 Or attached Figure 4 The track partitions shown are A, B, C, and D.

[0027] Since there are no overlapping grid cells in the different track zones, place requests for grid cells containing different track zones can be processed in parallel to reduce response time. If the transport vehicle needs to travel across different track zones, the place requests issued by the transport vehicle may involve two or more track zones.

[0028] Correspondingly, the blocking control system includes a partition determination unit and an authorization unit. The partition determination unit determines which track partition(s) the grid cell to be occupied by a received placeholder request belongs to and decides on the processing strategy based on the determination result. To facilitate the simultaneous processing of multiple placeholder requests, the partition determination unit can adopt multi-threaded parallel processing or multi-process parallel processing. The authorization unit can adopt multi-threaded or multi-process parallel processing of request tasks from multiple request queues. Each request queue corresponds to a track partition. For example, in the above three track partitions A, B, and C, there are three threads or processes and three request queues A1, B1, and C1. The grid cell to be occupied by the placeholder request or sub-request in request queue A1 belongs to track partition A, the grid cell to be occupied by the placeholder request or sub-request in request queue B1 belongs to track partition B, and the grid cell to be occupied by the placeholder request or sub-request in request queue C1 belongs to track partition C.

[0029] Correspondingly, as shown in the appendix Figure 5 As shown, when the control system receives a request from a transport vehicle to occupy a passageway comprising at least one grid cell, it determines whether the grid cell to be occupied by the request belongs to a track zone. When it is determined that the grid cell to be occupied by the placeholder request belongs to a track partition, the placeholder request is added to the request queue corresponding to the track partition to which the grid cell to be occupied belongs for authorization processing. When it is determined that the grid cell to be occupied by the placeholder request belongs to multiple track partitions, the placeholder request is divided into multiple sub-requests. Each sub-request is added to the request queue corresponding to the track partition to which the grid cell to be occupied by the sub-request belongs for authorization processing. The grid cell to be occupied by a sub-request is a grid cell belonging to the same track partition as the grid cell to be occupied by the placeholder request. The authorization processing involves determining whether the right to occupy the grid cell required by the placeholder request and the sub-request is granted to the transport vehicle that issued the placeholder request.

[0030] For example, as shown in the appendix Figure 6 As shown, in the track including track zone A and track zone B, transport vehicle V01 needs to occupy the passage area including grid cells 52, 42, 32 and 22. When the blockade control system receives the request from transport vehicle V01 to occupy grid cells 52, 42, 32 and 22, the blockade control system's zone determination unit determines that grid cells 52, 42, 32 and 22 all belong to track zone A. Then, the occupancy request can be added to the request queue A1 corresponding to track zone A for authorization processing.

[0031] As attached Figure 6 As shown, transport vehicle V02 needs to occupy grid cells 44, 100, 101, 45, and 46. When the blocking control system receives the request from transport vehicle V02 to occupy grid cells 44, 100, 101, 45, and 46, the partition determination unit of the blocking control system determines that grid cells 44 and 100 belong to track partition A, and grid cells 101, 45, and 46 belong to track partition B. The partition determination unit then generates two sub-requests: one sub-request REQ1 requests to occupy grid cells 44 and 100, and the other sub-request REQ2 requests to occupy grid cells 101, 45, and 46. Subsequently, sub-request REQ1 is added to the request queue A1 corresponding to track partition A for authorization processing, and sub-request REQ2 is added to the request queue B1 corresponding to track partition B for authorization processing.

[0032] Furthermore, after dividing into multiple sub-requests, if multiple sub-requests are added to their respective request queues simultaneously, assuming that the right to occupy the grid cell to be occupied by a sub-request is granted to the transport vehicle corresponding to that sub-request, but the grid cell to be occupied by that sub-request is downstream of the grid cell to be occupied by another sub-request, and the right to occupy the grid cell to be occupied by the other sub-request has not been fully granted to the transport vehicle, then a message of occupation failure will be sent back to the transport vehicle. At this time, the grid cell to which the right to occupy was granted will become invalid, which leads to an invalid authorization process and also affects other transport vehicles from occupying the grid cell.

[0033] Therefore, after dividing into multiple sub-requests, the order in which each sub-request is added to its corresponding request queue is determined according to the order in which the grid units to be occupied by each sub-request. When it is determined that the grid units to be occupied by a preceding sub-request have been authorized to the transport vehicle corresponding to the sub-request, the next sub-request after the preceding sub-request is added to its corresponding request queue.

[0034] For example, in the example of transport vehicle V02 above, transport vehicle V02 needs to move sequentially through grid cells 44, 100, 101, 45, and 46. The partitioning determination unit will first add sub-request REQ1 to the request queue A1 corresponding to track partition A. When it is determined that the right to occupy grid cells 44 and 100 requested by sub-request REQ1 has been granted to transport vehicle V02, the partitioning determination unit will then add sub-request REQ2 to the request queue corresponding to track partition B for authorization processing. If the right to occupy any grid cell in sub-request REQ1 has not been granted to transport vehicle V02, the authorization of subsequent grid cells will be stopped, and sub-request REQ2 will not be added to the request queue B1 corresponding to track partition B. Simultaneously, a message of failure to occupy will be sent to transport vehicle V02. For example, if the right to occupy grid cell 44 has not been granted to transport vehicle V02, the authorization of grid cell 100 will not be performed, and sub-request REQ2 will not be added to the request queue B1 corresponding to track partition B. If the right to occupy any of the grid cells requested by sub-request REQ2 is not granted to V02, then the authorization of subsequent grid cells is stopped and a message of occupancy failure is sent to transport vehicle V02. When occupancy failure is confirmed, sub-request REQ1 in request queue A1 and sub-request REQ2 in request queue B1 are cleared.

[0035] Furthermore, since multiple sub-requests need to be added sequentially to their respective request queues, later sub-requests will be processed later. If a later sub-request is added to the end of its corresponding request queue, and the queue still has multiple pending placeholder requests and / or sub-requests, the later sub-request will have to wait a certain amount of time before being processed. Consequently, the grid cells occupied by earlier sub-requests will be occupied for a longer period, affecting the occupancy of other transport vehicles. Therefore, to ensure that later sub-requests are processed as quickly as possible when there are many sub-requests, when a placeholder request is divided into more than two sub-requests, at least for the last sub-request, if the grid cells occupied by its preceding sub-requests have been allocated to the transport vehicle corresponding to that sub-request, the last sub-request is added to the head of its corresponding request queue.

[0036] Furthermore, when adding a placeholder request or sub-request to the request queue, the insertion position of the placeholder request or sub-request in the request queue is determined according to the priority of the transport task performed by the transport vehicle corresponding to the placeholder request or sub-request. Specifically, when the transport task performed by the transport vehicle corresponding to a placeholder request or sub-request needs to be processed first, the placeholder request or sub-request is added to the head of its corresponding request queue. Even further, when the transport task to be performed by a transport vehicle needs to be processed first, the placeholder request sent by the transport vehicle to the control system includes all grid cells traversed by its optimal path, thus effectively ensuring that urgent transport tasks can be processed in a timely manner.

[0037] When the control system plans a movement path for a transport vehicle, if the travel time of a feasible route is less than the travel time of other feasible routes and the difference in travel time does not exceed a first threshold, and if the feasible route also passes through a main route that connects the track zone where the starting point is located and other track zones except the track zone where the destination of the transport vehicle is to be moved, if the cross-regional traffic volume at the main route reaches a second threshold, then the feasible route is not selected; if the cross-regional traffic volume at the main route is less than the second threshold, then the feasible route is selected.

[0038] For details, see attached. Figure 7 As shown, a transport task requires moving transport vehicle V03, located in grid cell 31 (starting point), to grid cell 55 (ending point). Two feasible routes with the same travel distance are planned: Route 1 and Route 2. Both routes pass through track zones A and C. Route 1 includes grid cells 32, 33, and 34 belonging to track zone A, and grid cells 35, 39, 45, 53, 54, and 55 belonging to track zone C. Route 2 includes grid cells 32, 33, and 34 belonging to track zone A, and grid cells 35, 36, 37, 41, 47, and 55 belonging to track zone C.

[0039] However, Route 1 requires two direction changes at grid cells 35 and 53, while Route 2 only requires one direction change at grid cell 37. Each direction change requires the transport vehicle to decelerate to a stop, then adjust its mechanical structure and wheels to achieve the change, followed by re-acceleration. Therefore, without other interference, Route 1 takes longer, assuming the difference in travel time between Route 1 and Route 2 does not exceed the first threshold. Furthermore, grid cells 35, 36, 37, and 38 are the main routes connecting track zones A and B. Therefore, if the cross-regional traffic between track zones A and B is low (i.e., the cross-regional traffic on the main routes is less than the second threshold), Route 2 can be chosen as the optimal path. Conversely, if the cross-regional traffic between track zones A and B is high (i.e., the cross-regional traffic on the main routes is greater than or equal to the second threshold), Route 1 can be chosen as the optimal path. The control system can periodically calculate the cross-regional traffic volume of the main route in each cycle or the average cross-regional traffic volume of the main route throughout the entire operating cycle as a basis for judgment, without any limitation here.

[0040] Similar to existing technologies, after occupying a passageway, the transport vehicle can move within that passageway. When the transport vehicle moves to a predetermined position within a passageway, it sends a request to the control system to occupy the next passageway. If the transport vehicle continues to move to a deceleration position and still has not obtained the right to occupy the next passageway, it decelerates. More preferably, during the deceleration process, the transport vehicle reduces its speed in stages or decelerates uniformly based on the distance between its current position and the end of the currently occupied passageway. This helps to avoid the problem of the transport vehicle maintaining high speed to the end of its occupied passageway (the last grid cell of the occupied passageway) without obtaining the right to occupy the next passageway and thus stopping.

[0041] For example, as shown in the appendix Figure 8 As shown, the transport vehicle receives a movement command to travel from grid cell 22 to grid cell 32. When the transport vehicle obtains the right to occupy the passage area including grid cells 22-28 from the control system, it can move within that passage area. Based on its own speed, the transport vehicle decides to continue requesting the right to occupy the next passage area including grid cells 29, 30, 81, and 82 from the blockade control system at grid cell 24. If the transport vehicle enters grid cell 26 and still has not received a response from the blockade control system, or if the received response indicates a failure to occupy the passage area, the transport vehicle will begin to decelerate at grid cell 26 until it stops at grid cell 28.

[0042] This invention has many other embodiments, and all technical solutions formed by equivalent transformation or equivalent transformation fall within the protection scope of this invention.

Claims

1. A transport system comprising a track having a set of grid cells and a transport vehicle traveling on said track, the transport vehicle communicating with a control system, characterized in that: The track is divided into multiple track zones. When the control system receives a request from a transport vehicle to occupy a passageway that includes at least one grid cell, it determines whether the grid cell to be occupied by the request belongs to a track zone. When it is determined that the grid cell to be occupied by the placeholder request belongs to a track partition, the placeholder request is added to the request queue corresponding to the track partition to which the grid cell to be occupied belongs for authorization processing. When it is determined that the grid cell to be occupied by the placeholder request belongs to multiple track partitions, the placeholder request is divided into multiple sub-requests, and each sub-request is added to the request queue corresponding to the track partition to which the grid cell to be occupied by the sub-request belongs for authorization processing. The grid cell to be occupied by a sub-request is the grid cell belonging to the same track partition among the grid cells to be occupied by the placeholder request.

2. The handling system according to claim 1, characterized in that: The control system employs multi-threading or multi-processing to process multiple request queues in parallel.

3. The handling system according to claim 1, characterized in that: After dividing the request into multiple sub-requests, the order in which each sub-request is added to its corresponding request queue is determined according to the order in which the grid cells to be occupied by each sub-request. Once it is determined that the grid cells to be occupied by a preceding sub-request have been authorized to the transport vehicle corresponding to that sub-request, the next sub-request after the preceding sub-request is added to its corresponding request queue.

4. The handling system according to claim 3, characterized in that: When a placeholder request is divided into more than 2 sub-requests, at least for the last sub-request, when all the grid cells to be occupied by the previous sub-requests have been authorized to the transport vehicle corresponding to the sub-request, the last sub-request is added to the head of its corresponding request queue.

5. The handling system according to claim 3, characterized in that: When adding a placeholder request or sub-request to the request queue, the insertion position of the placeholder request or sub-request in the request queue is determined according to the priority of the transport task performed by the transport vehicle corresponding to the placeholder request or sub-request.

6. The handling system according to claim 5, characterized in that: When a transport vehicle corresponding to a placeholder request or sub-request needs to prioritize its transport task, the placeholder request or sub-request is added to the head of its corresponding request queue.

7. The handling system according to claim 1, characterized in that: When the control system plans a movement path for a transport vehicle, if it determines that the travel time of a feasible route is less than the travel time of other feasible routes and the difference in travel time does not exceed a first threshold, and the feasible route passes through a main route that connects the track zone where the starting point is located and other track zones except the track zone where the destination to which the transport vehicle is to be moved is located, if the cross-regional traffic volume at the main route reaches a second threshold, then the feasible route is not selected. If the cross-regional traffic volume at the main route is less than the second threshold, then the feasible route is selected.

8. The handling system according to claim 1, characterized in that: When the transport vehicle moves to a predetermined position in a passageway, it sends a request to the control system to occupy the next passageway. If the transport vehicle continues to move to the deceleration position and still has not obtained the right to occupy the next passageway, the transport vehicle decelerates.

9. The handling system according to claim 8, characterized in that: During the deceleration process, the transport vehicle reduces its speed in stages or decelerates uniformly based on the distance between its current location and the end point of the currently occupied passageway.

10. The handling system according to any one of claims 1-9, characterized in that: When a transport vehicle has a transport task that needs to be prioritized, the vehicle sends a occupancy request to the control system, which includes all grid cells that its optimal path passes through.

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