Transport system

Abstract

The invention discloses a carrying system, which comprises a track and a carrying vehicle running on the track, the carrying vehicle communicates with a control system, the track is divided into a plurality of track subareas, and the control system receives an occupying request that one carrying vehicle requests to occupy one passing interval. Determining whether the grid unit to be occupied by the placeholder request belongs to a track partition or not; if yes, adding the placeholder request to a corresponding request queue for authorization processing; if not, the occupation request is divided into a plurality of sub-requests, each sub-request is added to the corresponding request queue to be subjected to authorization processing, and the grid units needing to be occupied by one sub-request are the grid units of the same track partition. According to the method, the occupation request of the carrier can be processed in parallel through the multiple request queues, the processing efficiency can be improved to the maximum extent, the response time of the control system is shortened, the carrying efficiency of the whole carrying system is improved, and the carrier can run more smoothly.

Description

Technical Field

[0001] The present invention relates to the field of automatic handling equipment, in particular to a handling system. Background Art

[0002] The overhead transport vehicle system (OHT system) is an important equipment used for handling materials such as wafer cassettes in semiconductor manufacturing plants.

[0003] Patent document CN120057518A discloses a usable transport system.

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

[0005] However, in large factories, the number of transport vehicles running on the tracks can even reach thousands, and each transport vehicle will send a space occupation request every 1-2 seconds. The control system will have to 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 frequently slow down and stop during operation, which not only reduces traffic efficiency, but also increases material vibration and wheel wear on the transport vehicles. Summary of the Invention

[0006] The purpose of the present invention is to solve the above problems existing in the prior art and to provide a transport system.

[0007] The purpose of the present invention is achieved through the following technical solutions: A transport system includes a track having a set of grid cells and a transport vehicle traveling on the track, the transport vehicle communicating with a control system, the track being divided into a plurality of track partitions, and the control system, upon receiving a transport vehicle requesting to occupy a passage section including at least one grid cell, determines whether the grid cell to be occupied by the occupation request belongs to a track partition; When it is determined that the grid unit to be occupied by the placeholder request belongs to a track partition, the placeholder request is added to a request queue corresponding to the track partition to which the grid unit to be occupied by the placeholder request belongs for authorization processing; When it is determined that the grid unit 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 unit to be occupied by the sub-request belongs for authorization processing. The grid unit to be occupied by a sub-request is a grid unit among the grid units to be occupied by the placeholder request that belongs to the same track partition.

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

[0009] Preferably, after being divided into multiple sub-requests, the order in which each sub-request is added to its corresponding request queue is determined according to the order of the grid units to be occupied by each sub-request. When it is determined that all the grid units to be occupied by a previous sub-request are authorized to the transport vehicle corresponding to the sub-request, a sub-request following the previous sub-request is added to its corresponding request queue.

[0010] Preferably, when the number of sub-requests into which a placeholder request is divided is greater than 2, at least for the last sub-request, when all the grid units to be occupied by the previous sub-requests are authorized to the transport vehicle corresponding to the sub-request, the last sub-request is added to the head of the 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 task to be performed by a transport vehicle corresponding to a placeholder request or sub-request needs to be processed in priority, the placeholder request or sub-request is added to the head of the corresponding request queue.

[0013] Preferably, when the control system plans a moving path for a transport vehicle, when it is determined 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, if at the same time the feasible route passes through a main route, and the main route connects the track partition where the starting point is located and other track partitions except the track partition where the end point to which the transport vehicle is to move is located, if the cross-regional traffic volume at the main route reaches a second threshold, the feasible route is not selected; if the cross-regional traffic volume at the main route is less than the second threshold, the feasible route is selected.

[0014] Preferably, when the transport vehicle moves to a predetermined position in a traffic interval, it sends a request to the control system to occupy the next traffic interval. When the transport vehicle continues to move to the deceleration position and still fails to obtain the right to occupy the next traffic interval, the transport vehicle decelerates.

[0015] Preferably, during the deceleration process, the transport vehicle reduces its speed in stages or decelerates uniformly according to the distance between its current position and the end point of the passage section it currently occupies.

[0016] Preferably, when a transport task to be performed by a transport vehicle needs to be processed in priority, the occupancy request sent by the transport vehicle to the control system includes all grid cells passed by its optimal path.

[0017] The advantages of the technical solution of the present invention are mainly reflected in: The transport system of the present invention divides the track into different track partitions, so that when the control system receives a place-occupancy request from a transport vehicle, it can add the place-occupancy request to the request queue of the different track partition according to the track partition to which the grid unit belongs for authorization processing, thereby being able to process the place-occupancy request of the transport vehicle in parallel through multiple request queues, which can maximize the processing efficiency, reduce the response time of the control system, and be beneficial to improving the transport efficiency of the entire transport system, and is beneficial to smoother operation of the transport vehicle, improving operation safety, and extending the service life of the transport vehicle.

[0018] When adding sub-requests to their respective corresponding request queues, the present invention adds them in sequence, and only adds the next sub-request after all the grid units to be occupied by the previous sub-request are granted to transport vehicles. This can effectively avoid the situation where the grid units to be occupied by the previous sub-request are not granted to transport vehicles, while the grid units to be occupied by the later sub-requests are all granted to transport vehicles, resulting in the grid units to be occupied by the later sub-requests being invalidly occupied and affecting the occupation of other transport vehicles, thereby ensuring the rationality of grid unit allocation.

[0019] When the grid unit to be occupied by a placeholder request belongs to multiple grid partitions, the present invention adds the last sub-request to the head of the request queue when adding it to the corresponding request queue, which can effectively ensure that the sub-request is processed as soon as possible, so that a placeholder request can be processed and completed in time to improve the utilization efficiency of the authorized grid unit.

[0020] The present invention determines the position of the placeholder request or sub-request in the corresponding request queue according to the priority of the handling task, so that the authorization corresponding to the high-priority handling task can 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. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 is a schematic diagram of a track of the present invention; Figure 2 yes Figure 1 Schematic diagram of the orbital division into three orbital partitions; Figure 3 yes Figure 1 A schematic diagram of dividing the track into four track partitions; Figure 4 yes Figure 1Another diagram of dividing the track into four track partitions; Figure 5 is a flow chart of the control system of the present invention processing a placeholder request; Figure 6 It is a schematic diagram of the track of the present invention being divided into two track partitions; Figure 7 It is a schematic diagram of planning two feasible routes for a transport vehicle in the present invention; Figure 8 It is a schematic diagram of the transport vehicle of the present invention requesting a subsequent passage section and deceleration processing during operation. DETAILED DESCRIPTION

[0022] The objects, advantages, and features of the present invention are illustrated and explained through the following non-limiting description of preferred embodiments. These embodiments are merely typical examples of the application of the technical solutions of the present invention, and any technical solutions formed by equivalent substitution or equivalent transformation fall within the scope of protection claimed by the present invention.

[0023] In the description of the scheme, it should be noted that the terms "center," "upper," "lower," "left," "right," "front," "back," "vertical," "horizontal," "inner," and "outer," etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings and are intended solely for ease of description and simplification. They do not indicate or imply that the devices or components referred to must have a specific orientation, be constructed, or operate in a specific orientation. Therefore, they should not be construed as limitations on 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 transport system disclosed in the present invention is explained below with reference to the accompanying drawings, including a track having a group of grid units and a transport vehicle traveling on the track. The transport vehicle communicates with a control system. The specific structure of the track and the transport vehicle can be referred to the patent literature cited in the background technology and will not be described here in detail.

[0025] At the same time, as in the patent literature cited in the background technology, the control system also includes a transportation control system and a blocking control system. The transportation control system is used to receive work tasks, determine the transport vehicles that perform various work tasks, plan movement paths for the transport vehicles that perform work tasks, and instruct each transport vehicle to perform work tasks according to the planned movement paths. The work tasks include but are not limited to transportation tasks, scheduling tasks, and unlocking tasks. The blocking control system is used for authorization management and status management of each grid unit.

[0026] Different from the prior art, the present invention divides the track into multiple track partitions. The specific number and division principle of the track partitions depend on the grid track layout characteristics and the distribution of processing equipment and cache equipment under the track. Usually, the track section where the transport vehicle travels frequently is divided into a track partition, while the connection part of each track partition is usually less used and can be used as a connection area. For example, for the attached Figure 1 The track shown in the figure can be divided into the following Figure 2 Track partition A, track partition B and track partition C as shown; or the track can be divided into Figure 3 or attached Figure 4 Track partition A, track partition B, track partition C, and track D are shown.

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

[0028] Correspondingly, the blocking control system includes a partition determination unit and an authorization unit. The partition determination unit is used to determine which track partition or partitions the grid unit to be occupied by a received placeholder request belongs to and decide what processing strategy to adopt based on the determination result. In order 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 for request tasks of multiple request queues. Each request queue corresponds to a track partition. For example, for the three track partitions A, B, and C mentioned above, there are three threads or processes and three request queues A1, B1, and C1. The grid unit to be occupied by the placeholder request or sub-request in request queue A1 belongs to track partition A, the grid unit to be occupied by the placeholder request or sub-request in request queue B1 belongs to track partition B, and the grid unit 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 attached Figure 5 As shown, when the control system receives a position occupation request from a transport vehicle requesting to occupy a passage section including at least one grid unit, it determines whether the grid unit to be occupied by the position occupation request belongs to a track partition; When it is determined that the grid unit to be occupied by the placeholder request belongs to a track partition, the placeholder request is added to a request queue corresponding to the track partition to which the grid unit to be occupied by the placeholder request belongs for authorization processing; If 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 cells to be occupied by a sub-request are the grid cells belonging to the same track partition as the grid cells to be occupied by the placeholder request. The authorization processing determines whether the right to occupy the grid cells to be occupied by the placeholder request and the sub-requests is granted to the transport vehicle that issued the placeholder request.

[0030] For example, as attached Figure 6 As shown, in the track including track partition A and track partition B, transport vehicle No. V01 needs to occupy the passage section including grid units No. 52, No. 42, No. 32 and No. 22. When the blocking control system receives the occupancy request from transport vehicle No. V01 to occupy grid units No. 52, No. 42, No. 32 and No. 22, the partition determination unit of the blocking control system determines that grid units No. 52, No. 42, No. 32 and No. 22 all belong to track partition A, and then the occupancy request can be added to the request queue A1 corresponding to track partition A for authorization processing.

[0031] As attached Figure 6 As shown, transport vehicle No. V02 needs to occupy grid units No. 44, No. 100, No. 101, No. 45 and No. 46. When the blocking control system receives the occupancy request from transport vehicle No. V02 to occupy grid units No. 44, No. 100, No. 101, No. 45 and No. 46, the partition determination unit of the blocking control system determines that grid units No. 44 and No. 100 belong to track partition A, and grid units No. 101, No. 45 and No. 46 belong to track partition B. Then the partition determination unit generates two sub-requests, one sub-request REQ1 requests to occupy grid units No. 44 and No. 100, and the other sub-request REQ2 requests to occupy grid units No. 101, No. 45 and No. 46. Subsequently, the sub-request REQ1 is added to the request queue A1 corresponding to track partition A for authorization processing, and the sub-request REQ2 is added to the request queue B1 corresponding to track partition B for authorization processing.

[0032] Furthermore, after being divided into multiple sub-requests, if the multiple sub-requests are added to their respective corresponding request queues at the same time, assuming that the occupancy rights of the grid unit to be occupied by a sub-request are all granted to the transporter corresponding to the sub-request, but the grid unit to be occupied by the sub-request is downstream of the grid unit to be occupied by another sub-request, and the occupancy rights of the grid unit to be occupied by the other sub-request are not all granted to the transporter, then a message of occupation failure will be fed back to the transporter. At this time, the grid unit granted the occupancy right will become invalid, which results in an invalid authorization process and also affects other transporters occupying the grid unit.

[0033] Therefore, after being divided into multiple sub-requests, the order in which each sub-request is added to its corresponding request queue is determined according to the order of the grid units to be occupied by each sub-request. When it is determined that all the grid units to be occupied by a previous sub-request are authorized to the transport vehicle corresponding to the sub-request, the sub-request after the previous sub-request is added to its corresponding request queue.

[0034] For example, in the example of transport vehicle V02, transport vehicle V02 needs to move sequentially through grid cells 44, 100, 101, 45, and 46. The partition determination unit will first add sub-request REQ1 to request queue A1 corresponding to track partition A. Upon determining that the occupancy rights of grid cells 44 and 100 requested by sub-request REQ1 are both granted to transport vehicle V02, the partition determination unit will then add sub-request REQ2 to the request queue corresponding to track partition B for authorization. If the occupancy rights of any grid cell in sub-request REQ1 are not granted to transport vehicle V02, authorization of subsequent grid cells will be stopped, and sub-request REQ2 will not be added to request queue B1 corresponding to track partition B. At the same time, a message indicating an occupation failure will be fed back to transport vehicle V02. For example, if the occupancy rights of grid cell 44 are not granted to transport vehicle V02, authorization of grid cell 100 will not be performed, and sub-request REQ2 will not be added to request queue B1 corresponding to track partition B. If the occupancy rights for any of the grid cells requested by sub-request REQ2 are not granted to V02, subsequent authorizations for grid cells are stopped and a message indicating occupancy failure is fed back to transporter V02. Upon confirmation of occupancy failure, 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 to their respective corresponding request queues in order, the later sub-requests will be processed later. If the later sub-request is added to the end of its corresponding request queue, and the request queue still has multiple placeholder requests and / or sub-requests to be processed, the later sub-request will need to wait for a certain amount of time before being processed, and the grid unit occupied by the previous sub-request will be occupied for a longer time, thereby affecting the occupancy of other transport vehicles. Therefore, in order to process the later sub-requests as quickly as possible when there are many sub-requests divided, when the number of sub-requests divided into a placeholder request is greater than 2, at least for the last sub-request, when the grid units to be occupied by the previous sub-requests are all authorized to the transport vehicle corresponding to the sub-request, the last sub-request will be added to the head of its corresponding request queue.

[0036] Furthermore, when a placeholder request or sub-request is added 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 to be performed by the transport vehicle corresponding to the placeholder request or sub-request. Specifically, when the transport task to be performed by the transport vehicle corresponding to a placeholder request or sub-request needs to be processed with priority, the placeholder request or sub-request is added to the head of the corresponding request queue. Furthermore, when the transport task to be performed by a transport vehicle needs to be processed with priority, the placeholder request sent by the transport vehicle to the control system includes all grid cells passed by its optimal path, which can effectively ensure that urgent transport tasks can be processed in a timely manner.

[0037] When planning a moving path for a transport vehicle, the control system 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 value. If at the same time, the feasible route passes through a main route, and the main route connects the track partition where the starting point is located and other track partitions except the track partition where the end point to which the transport vehicle is to move is located, if the cross-regional traffic volume at the main route reaches a second threshold value, the feasible route is not selected; if the cross-regional traffic volume at the main route is less than the second threshold value, the feasible route is selected.

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

[0039] However, Route 1 requires two directional switches, at grid cells 35 and 53, while Route 2 only requires one, at grid cell 37. Each time the transporter switches direction, it must slow down to a stop, then re-accelerate by manipulating its own mechanical structure and wheels to switch direction. Therefore, in the absence of 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 sections A and B. Therefore, if the cross-regional traffic between track sections A and B is low—that is, the cross-regional traffic on the main route is less than the second threshold—Route 2 can be selected as the optimal path. Conversely, if the cross-regional traffic between track sections A and B is high—that is, the cross-regional traffic on the main route is greater than or equal to the second threshold—Route 1 can be selected as the optimal path. The control system may periodically count the cross-regional traffic volume of the main route in each cycle or the average cross-regional traffic volume of the main route during the entire operating cycle as a basis for judgment, which is not limited here.

[0040] As with the prior art, after occupying a passageway, the transporter can move within that passageway. When the transporter reaches a predetermined position within a passageway, it sends a request to the control system to occupy the next passageway. If the transporter continues to move to the deceleration position and still does not obtain the right to occupy the next passageway, the transporter decelerates. More preferably, during the deceleration process, the transporter reduces its speed in stages or decelerates evenly based on the distance between its current position and the end of the currently occupied passageway. This helps to minimize the problem of the transporter maintaining high speed and stopping at the end of its occupied passageway (the last grid cell of the occupied passageway) without obtaining the right to occupy the next passageway.

[0041] For example, as attached Figure 8 As shown, the transport vehicle receives a movement instruction to move from grid unit 22 to grid unit 32. When the transport vehicle obtains the occupancy right of the passage section including grid units 22 to 28 from the control system, the transport vehicle will be able to move within this passage section. When the transport vehicle continues to request the occupancy right of the next passage section including grid units 29, 30, 81, and 82 from the blocking control system at grid unit 24 based on its own speed decision. If the transport vehicle still does not receive a response result from the blocking control system when entering grid unit 26 or the response result received is an occupancy failure, the transport vehicle will start to slow down at grid unit 26 until it stops at grid unit 28.

[0042] There are many implementation methods of the present invention, and all technical solutions formed by equivalent transformation or equivalent transformation fall within the protection scope of the present invention.

Claims

1. A transport system comprising a track having a set of grid cells and a transport vehicle traveling on the track, the transport vehicle communicating with a control system, characterized in that: The track is divided into a plurality of track partitions, and the control system, upon receiving a transport vehicle occupying a passage section including at least one grid unit, determines whether the grid unit to be occupied by the occupying request belongs to a track partition; When it is determined that the grid unit to be occupied by the placeholder request belongs to a track partition, the placeholder request is added to a request queue corresponding to the track partition to which the grid unit to be occupied by the placeholder request belongs for authorization processing; When it is determined that the grid unit 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 unit to be occupied by the sub-request belongs for authorization processing. The grid unit to be occupied by a sub-request is a grid unit among the grid units to be occupied by the placeholder request that belongs to the same track partition.

2. The transport system according to claim 1, wherein: The control system uses multi-threading or multi-processing to process request tasks of multiple request queues in parallel.

3. The transport system according to claim 1, wherein: After being divided into multiple sub-requests, the order in which each sub-request is added to its corresponding request queue is determined according to the order of the grid units to be occupied by each sub-request. When it is determined that all the grid units to be occupied by a previous sub-request are authorized to the transport vehicle corresponding to the sub-request, the sub-request after the previous sub-request is added to its corresponding request queue.

4. The transport system according to claim 3, wherein: When the number of sub-requests divided into a placeholder request is greater than 2, at least for the last sub-request, when all the grid units to be occupied by the previous sub-requests are authorized to the transport vehicle corresponding to the sub-request, the last sub-request is added to the head of the corresponding request queue.

5. The transport system according to claim 3, wherein: When a placeholder request or sub-request is added 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 transport system according to claim 5, wherein: When a transport task performed by a transport vehicle corresponding to a placeholder request or subrequest needs to be processed first, the placeholder request or subrequest is added to the head of the corresponding request queue.

7. The transport system according to claim 1, wherein: When planning a moving path for a transport vehicle, the control system determines that a feasible route has a travel time that is less than the travel time of other feasible routes and the travel time difference 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 transport vehicle is to move to the destination, and if the cross-zone traffic volume on the main route reaches a second threshold, then the feasible route is not selected; If the cross-region traffic volume at the main traffic route is less than a second threshold, the feasible route is selected.

8. The transport system according to claim 1, wherein: When the transport vehicle moves to a predetermined position in a traffic section, it sends a request to the control system to occupy the next traffic section. When the transport vehicle continues to move to the deceleration position and still does not obtain the right to occupy the next traffic section, the transport vehicle decelerates.

9. The transport system according to claim 8, wherein: During the deceleration process, the transport vehicle reduces its speed in stages or decelerates uniformly according to the distance between its current position and the end point of the passage section it currently occupies.

10. The transport system according to any one of claims 1 to 9, characterized in that: When a transport task to be performed by a transport vehicle needs to be processed in priority, the transport vehicle sends a position request to the control system including all grid cells that its optimal path passes through.

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