Transport System

Abstract

This conveyance system comprises: a plurality of conveyance vehicles that travel along a track and convey loads; and a controller that controls the travel of the plurality of conveyance vehicles. The track includes a first main track, and a plurality of branch tracks connected to the first main track via different merging points. The controller executes start control to start each conveyance vehicle stopped at a stop position of each of the plurality of branch tracks toward the first main track for each of the plurality of branch tracks. In the start control, depending on the presence or absence of the conveyance vehicle in a predetermined section on the track, the start of at least one of conveyance vehicles stopped at the stop position of each of the plurality of branch tracks is prohibited.

Description

[Technical Field]

[0001] One aspect of the present invention relates to a transport system. [Background technology]

[0002] A transport system is known that includes a plurality of transport vehicles that travel along a track and a controller that controls the travel of the plurality of transport vehicles. As a technology related to such a transport system, for example, Patent Document 1 describes a system in which each transport vehicle that has stopped at a stop position on each of a plurality of branch tracks of a track starts at a timing according to the count of a pitch timer for each of the plurality of branch tracks. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 6935846 Summary of the Invention [Problem to be solved by the invention]

[0004] In the above-described conveying system, for some reason, there may be an excess or shortage of transport vehicles on a certain section of the track. In this case, for example, due to a shortage of transport vehicles, the time available for transport vehicles to stop at a stop position corresponding to a loading port on a specific branch track may be shortened, and the transport vehicle may depart without being able to load its cargo. Furthermore, for example, due to a concentration of transport vehicles, the departure of a transport vehicle may be blocked by a preceding transport vehicle, causing a traffic jam. As a result, it becomes difficult for the transport vehicles to transport cargo smoothly.

[0005] One aspect of the present invention has been made in view of the above-described circumstances, and an object of the present invention is to provide a transport system that enables a transport vehicle to transport a load smoothly. [Means for solving the problem]

[0006] A conveying system according to one aspect of the present invention is a conveying system comprising a plurality of transport vehicles that travel along a track and transport loads, and a controller that controls the travel of the plurality of transport vehicles, wherein the track has a first main track and a plurality of branch tracks that connect to the first main track via different junctions, and the controller executes start control to cause each of the transport vehicles stopped at a stopping position on each of the plurality of branch tracks to start toward the first main track for each of the plurality of branch tracks, and the start control prohibits the start of at least some of the transport vehicles stopped at each stopping position on each of the plurality of branch tracks depending on the presence or absence of a transport vehicle in a predetermined section on the track.

[0007] In this conveyance system, each transport vehicle stopped at a stopping position on a plurality of branch tracks departs for each branch track, and at least one of the vehicles is prohibited from departing depending on the surplus or shortage of vehicles in a given section of the track. This prevents transport delays due to a shortage or congestion of transport vehicles, and enables the transport vehicles to transport loads smoothly.

[0008] In a conveyance system according to one aspect of the present invention, the track includes a second main track, the stop positions correspond to loading ports for loading the transport vehicles, the second main track branches into multiple branch tracks at different branch points, the predetermined sections include first sections on each of the multiple branch tracks that are sections upstream of the stop positions, and the departure control may prohibit a transport vehicle stopped at a stop position on one branch track from departing if there are no transport vehicles in the first section of one branch track and if there are no transport vehicles scheduled to enter the first section from the second main track. This allows a transport vehicle to be stopped at the stop position for a sufficient period of time even if there is a shortage of transport vehicles on one branch track, ensuring that the transport vehicle can be loaded during that time. In other words, it is possible to prevent a transport vehicle from departing one branch track without being able to be loaded.

[0009] In a conveyance system according to one aspect of the present invention, in the first section, unloading ports for unloading transport vehicles are arranged along the track, and the start control may prohibit a transport vehicle stopped at a stopping position on one branch track from starting if there is no transport vehicle that has unloaded at an unloading port on the first section of one branch track. In this case, it is possible to reliably prevent a transport vehicle from starting on one branch track without being able to load a load.

[0010] In a conveyance system according to one aspect of the present invention, the predetermined section includes a second section on the track that is a section from the stopping positions of multiple branch tracks to the most downstream junction, and the start control may prohibit the departure of all guided vehicles stopped at the respective stopping positions of the multiple branch tracks when other guided vehicles are present in the second section. In this case, it is possible to avoid congestion in the second section due to the concentration of guided vehicles.

[0011] In a conveyance system according to one aspect of the present invention, the start control may include starting each of the transport vehicles stopped at each stop position on each of the branch tracks at a timing that is repeated at a fixed cycle for each of the branch tracks, and determining again whether or not to prohibit a transport vehicle that has been prohibited from starting in a certain cycle from starting in the next cycle. In this case, starting each stopped transport vehicle at a fixed cycle improves the efficiency of transporting goods, while specifically achieving the above-mentioned effect, i.e., starting each transport vehicle according to the surplus or shortage of transport vehicles.

[0012] In a conveyance system according to one aspect of the present invention, in the start control, a guided vehicle that has been prohibited from starting for a predetermined period may be permitted to start in the next period. In this case, it is possible to prevent a guided vehicle that has been prohibited from starting in the start control from not conveying a load for a long period of time. [Effects of the Invention]

[0013] According to one aspect of the present invention, it is possible to provide a conveyance system that can improve the efficiency of transporting loads. [Brief explanation of the drawings]

[0014] [Figure 1] FIG. 1 is a schematic plan view showing a transport system according to an embodiment. [Figure 2] FIG. 2 is a side view showing the transport vehicle of the transport system of FIG. [Figure 3] FIG. 3 is a schematic plan view showing the first building side of the transport system of FIG. [Figure 4] FIG. 4 is a schematic plan view illustrating an example of start control when no guided vehicle is present in the first section in the transport system of FIG. [Figure 5] FIG. 5 is a schematic plan view illustrating an example of start control when a transport vehicle is present in the second section in the transport system of FIG. DETAILED DESCRIPTION OF THE INVENTION

[0015] An embodiment will be described below with reference to the drawings. In the description of the drawings, the same or corresponding elements are designated by the same reference numerals, and redundant description will be omitted. The dimensional proportions of the drawings do not necessarily correspond to those in the description.

[0016] As shown in FIG. 1, the conveyance system 1 is a system that performs point-to-point conveyance in which the origin and destination are patterned. The conveyance system 1 performs inter-building conveyance, delivering and receiving goods between a first building F1 and a second building F2. The conveyance system 1 includes a plurality of conveyance vehicles 10 and a controller 20. The conveyance vehicles 10 travel along a track 3 to convey goods. The conveyance vehicles 10 are configured to be able to transfer goods. The conveyance vehicles 10 are overhead traveling unmanned guided vehicles. The conveyance vehicles 10 are also referred to as, for example, carriages (conveyance carriages), overhead traveling vehicles (overhead traveling carriages), or traveling vehicles (traveling carriages). The number of conveyance vehicles 10 included in the conveyance system 1 is, for example, about 50, and varies depending on the required amount of conveyance and the conveyance distance.

[0017] As shown in FIG. 2, the transport vehicle 10 includes a traveling carriage 144, a power supply carriage 145 that receives power from the track 3, a θ drive 147, and a lateral feed unit 146 for feeding the portion below the traveling carriage 144 laterally relative to the track 3. The θ drive 147 rotates an elevation drive unit 148 in a horizontal plane to control the posture of the load L. The elevation drive unit 148 raises and lowers an elevation platform 149 that holds the load L, thereby transferring the load L between the transfer port 4. The elevation platform 149 chucks the load L at the flange 124 at the top of the load L. The lateral feed unit 146 and the θ drive 147 may not be provided. The load L is, for example, a container that stores multiple semiconductor wafers, but may also be a glass substrate, general parts, etc.

[0018] The track 3 is laid on, for example, the ceiling. The track 3 is supported by supports 141. The track 3 is a predetermined running path for the transport vehicle 10 to travel on. The track 3 is a one-way running path. In other words, in the transport system 1, the traveling direction (forward direction) of the transport vehicle 10 on the track 3 is set to one direction, and traveling in the opposite direction is prohibited. The track 3 has a closed track layout that is not affected from outside the track 3. Hereinafter, the terms "upstream" and "downstream" correspond to "upstream" and "downstream" respectively in the traveling direction of the transport vehicle 10.

[0019] In the example shown in FIG. 1, the track 3 includes main tracks 31 and 32, four first branch tracks 33a, 33b, 33c, and 33d that branch off from the main track 32 and merge with the main track 31, and four second branch tracks 34a, 34b, 34c, and 34d that branch off from the main track 31 and merge with the main track 32. The main tracks 31 and 32 are tracks that span between the first building F1 and the second building F2. The length of the main tracks 31 and 32 is, for example, 200 m. Between the first building F1 and the second building F2, the main tracks 31 and 32 are enclosed by a wall (not shown) and are closed. The main tracks 31 and 32, the first branch tracks 33a to 33d, and the second branch tracks 34a to 34d form a circular track on which multiple guided vehicles 10 travel in a circular motion.

[0020] The first branch tracks 33a-33d are arranged in the first building F1. The first branch tracks 33a-33d extend in parallel. The first branch tracks 33a-33d are arranged in a comb-like shape between the main tracks 31, 32 which extend in parallel. The first branch tracks 33a-33d are located, in this order, on the upstream side of the main track 31 (downstream side of the main track 32). The second branch tracks 34a-34d are arranged in the second building F2. The second branch tracks 34a-34d extend in parallel. The second branch tracks 34a-34d are arranged in a comb-like shape between the main tracks 31, 32 which extend in parallel. The second branch tracks 34a-34d are located, in this order, on the upstream side of the main track 32 (downstream side of the main track 31).

[0021] Next, a specific description will be given of the configuration and control of the transport system 1. In the following description, the configuration and control on the first building F1 side will be described, and the configuration and control on the second building F2 side will be omitted as appropriate because they are similar.

[0022] As shown in FIG. 3, the first branch tracks 33a-33d merge with the main track 31 at junctions 35a, 35b, 35c, and 35d. Each of the first branch tracks 33a-33d is connected to the main track 31 via junctions 35a, 35b, 35c, and 35d. In other words, the track 3 has multiple junctions 35a-35d that are spaced apart from one another on the main track 31. The main track 31 merges with each of the first branch tracks 33a-33d via junctions 35a, 35b, 35c, and 35d, which are different from one another. Note that, for example, the portion of the track 3 downstream of junction 35a is considered to be the main track 31, and the portion upstream of junction 35a is considered to merge with the first branch track 33a. The first branch tracks 33a to 33d are connected to the main track 31 via different junctions 35a to 35d, respectively. The junctions 35a to 35d are spaced apart from one another on the main track 31 by a predetermined distance.

[0023] The first branch tracks 33a-33d branch off from the main track 32 at branch points 36a, 36b, 36c, and 36d. Each of the first branch tracks 33a-33d is connected to the main track 32 via branch points 36a, 36b, 36c, and 36d. That is, the track 3 has a plurality of branch points, branch points 36a-36d, spaced apart from one another on the main track 32. The main track 32 branches off into the first branch tracks 33a-33d at different branch points 36a, 36b, 36c, and 36d. For example, the portion of the track 3 upstream of branch point 36a is considered to be the main track 32, and the portion downstream of branch point 36a is considered to branch off into the first branch track 33a. Each of the first branch tracks 33a-33d connects to the main track 32 via different branch points 36a-36d. The branch points 36a to 36d are spaced apart from one another on the main track 32 by a predetermined distance.

[0024] A "junction point" is a point where a branch track joins a main track. A "junction point" is a point where a branch track joins a main track. A "junction point" is a connection point where a branch track enters a main track. A "branch point" is a point where a main track joins a branch track. A "branch point" is a point where a main track enters a branch track. A "branch point" is a connection point where a main track enters a branch track. In the example shown in FIG. 3, main track 31 corresponds to the first main track, main track 32 corresponds to the second main track, and first branch tracks 33a to 33d correspond to the branch tracks.

[0025] Each of the first branch tracks 33a to 33d has a stop position corresponding to a delivery port 4 where the transport vehicle 10 delivers and receives the load L. The delivery port 4 is arranged along each of the first branch tracks 33a to 33d. The delivery port 4 is provided, for example, on a conveyor (not shown) that transports the load L. The delivery port 4 has an unloading port 41 and a loading port 42.

[0026] The unloading port 41 is a port for unloading the load L from the transport vehicle 10. At the unloading port 41, the load L is transported out after being placed thereat and before the arrival of the following transport vehicle 10. The unloading port 41 is arranged at a predetermined distance upstream of the loading port 42. In other words, the loading port 42 is arranged at a predetermined distance downstream of the unloading port 41. The loading port 42 is a port for loading the load L onto the transport vehicle 10. The loading port 42 is capable of transporting the load L into the port in a span in which multiple transport vehicles 10 arrive consecutively. The unloading port 41 and the loading port 42 are not particularly limited, and various known ports can be used.

[0027] As shown in Fig. 3, the controller 20 is an electronic control unit including a CPU (Central Processing Unit), a ROM (Read Only Memory), and a RAM (Random Access Memory). The controller 20 can be configured as software in which a program stored in the ROM is loaded onto the RAM and executed by the CPU. The controller 20 may also be configured as hardware including electronic circuits. The controller 20 communicates with the multiple guided vehicles 10 and controls the traveling of the multiple guided vehicles 10.

[0028] The controller 20 executes a start control for each of the first branch tracks 33a to 33d, which causes each of the transport vehicles 10 stopped at a stop position corresponding to each of the delivery ports 4 of the first branch tracks 33a to 33d (here, a stop position corresponding to the loading port 42) to start toward the main track 31. Note that, hereinafter, the stop position corresponding to the loading port 42 may also be simply referred to as the "stop position." The upstream and downstream of the start control correspond to the upstream and downstream of the main track 31, and the upstream and downstream of the approach control correspond to the upstream and downstream of the main track 32.

[0029] In the start control, the guided vehicle 10 stopped on the downstream first branch track among the first branch tracks 33a to 33d is caused to start simultaneously with or before the guided vehicle 10 stopped on the upstream first branch track. Specifically, in the start control, the guided vehicle 10 stopped on the first branch track 33d is caused to start simultaneously with or before the guided vehicle 10 stopped on the first branch track 33c. The guided vehicle 10 stopped on the first branch track 33c is caused to start simultaneously with or before the guided vehicle 10 stopped on the first branch track 33b. The guided vehicle 10 stopped on the first branch track 33b is caused to start simultaneously with or before the guided vehicle 10 stopped on the first branch track 33a.

[0030] More specifically, in the start control, each stopped guided vehicle 10 is started (forced to start) at a timing that is repeated at a fixed cycle for each of the first branch tracks 33a to 33d, regardless of whether or not a load L is loaded. For example, in the start control, a pitch timer for each of the first branch tracks 33a to 33d starts counting down from a reference pitch time. When the count of the pitch timer reaches 0, the guided vehicle 10 stopped at the stop position is started, and the count of the pitch timer is reset to the reference pitch time. Then, the pitch timer continues counting down. The reference pitch time may be a predetermined fixed value or a variable value. In this embodiment, the time axis of the pitch timer for each of the first branch tracks 33a to 33d is shifted so that the guided vehicle 10 stopped on the downstream first branch track starts first.

[0031] The controller 20 executes entry control to cause each of the multiple guide vehicles 10 traveling on the main track 32 to enter each of the first branch tracks 33a to 33d in sequence from the downstream side to the upstream side. Specifically, in the entry control, the guide vehicle 10 is caused to enter the first branch track 33a, the next guide vehicle 10 is caused to enter the first branch track 33b, the next guide vehicle 10 is caused to enter the first branch track 33c, the next guide vehicle 10 is caused to enter the first branch track 33d, and thereafter, such entry of the guide vehicles 10 is repeated.

[0032] In the approach control, a destination determination control is performed to determine (guide) the destination of the guided vehicle 10 traveling in a specific section R upstream of each of the branch points 36a to 36d on the main track 32. The specific section R is a straight section close to each of the branch points 36a to 36d. There are no particular limitations on the specific section R as long as it is upstream of each of the branch points 36a to 36d. The specific section R is not limited to a straight section, and may be a section including a curve, or may be any of various sections. In the destination determination control, a transfer port 4 of the destination (here, any of the unloading ports 41 of the first branch tracks 33a to 33d) is determined.

[0033] The controller 20 grasps the number of guided vehicles 10 present on each of the first branch tracks 33a to 33d (the number of entries). Specifically, in the entry control, the controller 20 increments by one the number of guided vehicles 10 present on any of the first branch tracks 33a to 33d corresponding to the destination at the timing when the destination is determined by the above-mentioned destination determination control. In the departure control, when the controller 20 starts a guided vehicle 10 stopped at a stop position on any of the first branch tracks 33a to 33d, the controller 20 decrements by one the number of guided vehicles 10 present on any of the first branch tracks 33a to 33d at the timing of the departure (countdown).

[0034] 1, the controller 20 executes virtual coupling control to perform the above-mentioned start control and entry control for each guided vehicle group including a plurality of guided vehicles 10 (four in this example) corresponding to the number of first branch tracks 33a to 33d. The controller 20 causes the plurality of guided vehicles 10 to travel along the orbits (main tracks 31, 32, first branch tracks 33a to 33d, and second branch tracks 34a to 34d) so that the orbital distances or orbital times are the same. Specifically, in the entry control, the controller 20 causes the transport vehicle 10 that has entered the first branch track 33d to enter the second branch track 34a, causes the transport vehicle 10 that has entered the first branch track 33c to enter the second branch track 34b, causes the transport vehicle 10 that has entered the first branch track 33b to enter the second branch track 34c, and causes the transport vehicle 10 that has entered the first branch track 33a to enter the second branch track 34d. In addition, during entry control, the transport vehicle 10 that has entered the second branch track 34d is made to enter the first branch track 33a, the transport vehicle 10 that has entered the second branch track 34c is made to enter the first branch track 33b, the transport vehicle 10 that has entered the second branch track 34b is made to enter the first branch track 33c, and the transport vehicle 10 that has entered the second branch track 34a is made to enter the first branch track 33d.

[0035] Here, in the departure control of this embodiment, the departure of at least one of the transport vehicles 10 stopped at the stopping positions corresponding to the respective loading ports 42 of the first branch tracks 33a to 33d is prohibited depending on whether or not there is a transport vehicle 10 in a predetermined section Z on the track 3. For example, the presence of a transport vehicle 10 in the predetermined section Z includes the presence of a reference position (such as the center position of the transport vehicle 10) that serves as a reference for the position of the transport vehicle 10 within the predetermined section Z. For example, the presence of a transport vehicle 10 in the predetermined section Z includes the actual presence of the transport vehicle 10 and the expected presence of the transport vehicle 10.

[0036] As shown in Fig. 3, the predetermined section Z includes a first section Z1 and a second section Z2. The first section Z1 is a section on the upstream side of the stopping positions corresponding to the loading ports 42 on each of the first branch tracks 33a to 33d. In the first section Z1, the unloading ports 41 are arranged along each of the first branch tracks 33a to 33d. In other words, the first section Z1 includes at least the stopping positions corresponding to the unloading ports 41. The first section Z1 is arranged so that a guided vehicle 10 present therein does not physically interfere with a guided vehicle 10 stopped at a stopping position corresponding to the loading port 42.

[0037] The second section Z2 is a section of the track 3 from the stopping positions of the first branch tracks 33a to 33d corresponding to the loading ports 42 to the most downstream junction 35d. The second section Z2 includes sections downstream of the stopping positions of the first branch tracks 33a to 33d corresponding to the loading ports 42, and a section of the main track 31 from the junction 35a to the junction 35d. The second section Z2 is also referred to as a gate-closed section. The second section Z2 is provided so that guided vehicles 10 present therein do not physically interfere with guided vehicles 10 stopped at the stopping positions corresponding to the loading ports 42.

[0038] In the departure control, when there is no guided vehicle 10 in the first section Z1 of one branch track 33 and there is no guided vehicle 10 scheduled to enter the first section Z1 of one branch track 33 from the main track 32, the departure of the guided vehicle 10 stopped at a stop position corresponding to the loading port 42 of one branch track 33 is prohibited. The one branch track 33 refers to any of the first branch tracks 33a to 33d. The guided vehicle 10 scheduled to enter the first section Z1 of one branch track 33 from the main track 32 is, for example, a guided vehicle 10 traveling on a specific section R, and whose destination has been determined to be an unloading port 41 along one branch track 33 by the destination determination control.

[0039] For example, in the departure control, in the first section Z1 of one branch track 33, if a transport vehicle 10 that has already unloaded at an unloading port 41 is not present (not stopped) at the stopping position corresponding to the unloading port 41, the departure of the transport vehicle 10 stopped at the stopping position of one branch track 33 is prohibited.

[0040] In the start control, all of the transport vehicles 10 stopped at the stop positions corresponding to the loading ports 42 of the first branch tracks 33a to 33d (in other words, a group of transport vehicles started by the start control in the same cycle) are prohibited from starting if there are other transport vehicles 10 other than the transport vehicle 10 in question in the second section Z2. The other transport vehicles 10 may be, for example, transport vehicles 10 included in the group of transport vehicles started by the start control in the immediately preceding cycle. Whether there are other transport vehicles 10 in the second section Z2 can be determined by the controller 20 based on the position information of each transport vehicle 10 obtained by, for example, periodically communicating with each transport vehicle 10.

[0041] In the start control, as described above, each guided vehicle 10 stopped at a stop position corresponding to each loading port 42 of the first branch tracks 33a to 33d is started at a timing that is repeated at a fixed cycle for each of the first branch tracks 33a to 33d. In the start control, for a guided vehicle that has been prohibited from starting in a certain cycle, it is determined again whether or not to prohibit its start in the next cycle. In addition, in the start control, for a guided vehicle 10 that has been prohibited from starting for a predetermined cycle, it is unconditionally permitted to start in the next cycle. The predetermined cycle corresponds to n cycles of the pitch timer (n is a set constant, for example, n=3).

[0042] FIG. 4 is a schematic plan view illustrating an example of start control when there is no guided vehicle 10 in the first section Z1 of the first branch track 33d in the conveyance system 1. In the example of FIG. 4, there is also no guided vehicle 10 scheduled to enter the first section Z1. As shown in FIG. 4, in the first section Z1 of the first branch track 33d, no guided vehicle 10 that has already unloaded at the unloading port 41 is stopped. In other words, in the first branch track 33d, there is no guided vehicle 10 available as a transportable empty carriage behind the guided vehicle 10X that is stopped at the stop position corresponding to the loading port 42. Therefore, in this case, the controller 20 prohibits the start of the guided vehicle 10X in the current cycle.

[0043] In the next cycle, it is determined again whether or not the transporting vehicle 10X is prohibited from starting. For example, in the next cycle, if a transporting vehicle 10 that has already unloaded at the unloading port 41 is stopped behind the transporting vehicle 10X, the prohibition on the transporting vehicle 10X's starting is lifted, and the transporting vehicle 10X starts sequentially in synchronization with each of the transporting vehicles 10 stopped at the stopping positions of the first branch tracks 33a to 33c.

[0044] 5 is a schematic plan view illustrating an example of start control when a guided vehicle 10 is present in the second section Z2 in the conveyance system 1. In the example of FIG. 5, the start control in the kth cycle causes each guided vehicle 10a stopped at each stop position on the first branch tracks 33a to 33d to start sequentially. At this time, the last guided vehicle 10b of the group of guided vehicles started in the start control in the (k-1)th cycle is still present in the second section Z2. Therefore, in this case, the controller 20 stops the start control in the kth cycle, and all stopped guided vehicles 10a are prohibited from starting.

[0045] As described above, in the conveyance system 1, each of the transport vehicles 10 stopped at a stop position on the first branch tracks 33a to 33d starts off on each of the first branch tracks 33a to 33d. At the same time, depending on the surplus or shortage of transport vehicles 10 in a predetermined section Z on the track 3, the departure of at least one of the transport vehicles 10 is prohibited. This prevents transport delays due to a shortage or overcrowding of transport vehicles 10, and enables the transport vehicles 10 to transport the load L smoothly.

[0046] In the conveyance system 1, the predetermined section Z includes a first section Z1. In the start control, if there is no guided vehicle 10 in the first section Z1 of one branch track 33, and if there is no guided vehicle 10 scheduled to enter the first section Z1 from the main track 32, the start of the guided vehicle 10 stopped at the stop position of one branch track 33 is prohibited. As a result, even if there is a shortage of guided vehicles 10 on one branch track 33, the guided vehicles 10 can be stopped at the stop position for a sufficient period of time, during which time the load of the guided vehicles 10 can be reliably carried out.

[0047] As a result, it is possible to prevent a transport vehicle 10 from starting (forcibly starting) without being able to load cargo on one branch track 33. Furthermore, even if an imbalance occurs between the number of transport vehicles 10 traveling in the direction from the first building F1 to the second building F2 and the number of transport vehicles 10 traveling in the direction from the second building F2 to the first building F1, it is possible to automatically eliminate the imbalance and achieve a balance. Even if one branch track 33 has a shortage of transport vehicles 10, transport vehicles 10 can be stored on the one branch track 33, and the shortage of transport vehicles 10 on the one branch track 33 can be resolved.

[0048] In the conveyance system 1, in the start control, when there is no conveyance vehicle 10 that has unloaded at the unloading port 41 in the first section Z1 of the one branch track 33, the start of the conveyance vehicle 10 stopped at the stopping position of the one branch track 33 is prohibited. In this case, for example, when there is no other conveyance vehicle 10 as an empty carriage immediately behind the stopped conveyance vehicle 10 on the one branch track 33, the start of the stopped conveyance vehicle 10 is prohibited, and it is possible to reliably prevent the stopped conveyance vehicle 10 from being forced to start without being able to load.

[0049] In the conveyance system 1, the predetermined section Z includes the second section Z2. In the start control, the start of all the guided vehicles 10 stopped at the respective stop positions of the first branch tracks 33a to 33d is prohibited when there is another guided vehicle 10b other than the said guided vehicle 10 in the second section Z2. In this case, it is possible to avoid congestion caused by the concentration of guided vehicles 10 in the second section Z2 and its surroundings.

[0050] In the start control, the conveyance system 1 starts each of the guided vehicles 10 stopped at the respective stop positions of the first branch tracks 33a to 33d at a timing that is repeated at a fixed cycle for each of the first branch tracks 33a to 33d, and for a guided vehicle 10 that has been prohibited from starting in a certain cycle, it is determined again whether or not to prohibit the start in the next cycle. In this case, by starting each of the stopped guided vehicles 10 at a fixed cycle, the conveyance efficiency of the load L is improved, and the above-mentioned effect, that is, the start of each guided vehicle 10 according to the surplus or shortage of guided vehicles 10, can be specifically realized. In addition, it is possible to suppress variations in the pace of conveyance.

[0051] In the start control, the transporting system 1 allows the transporting vehicle 10 that has been prohibited from starting for a predetermined period to start in the next period. In this case, it is possible to prevent the transporting vehicle 10 that has been prohibited from starting in the start control from not transporting the load L for a long period of time.

[0052] Although one embodiment of the present invention has been described above, the present invention is not limited to the above embodiment, and various modifications are possible without departing from the spirit of the invention.

[0053] In the above embodiment, the track 3 includes four first branch tracks 33a-33d, but the number of first branch tracks may be two, three, or five or more. Similarly, the track 3 includes four second branch tracks 34a-34d, but the number of second branch tracks may be two, three, or five or more.

[0054] In the above embodiment, in the start control, the vehicle is forced to start at a fixed period regardless of whether or not the load L is loaded, but the vehicle may also be started on the condition that the load L is loaded. In the above embodiment, a destination determination control is executed to determine the destination of the transport vehicle 10 traveling in the specific section R, but the destination determination control does not have to be executed, and the delivery port 4 of the destination may be determined at any timing. In the above embodiment, a virtual connection control is executed to control each transport vehicle group including multiple transport vehicles 10, but the virtual connection control does not have to be executed.

[0055] The constituent elements of one aspect of the present invention will be described below. <Invention 1> a plurality of transport vehicles that travel along a track and transport loads; A controller that controls the travel of the plurality of transport vehicles, The track includes a first main track and a plurality of branch tracks that connect to the first main track via different junctions, the controller executes a start control to cause each of the guided vehicles stopped at a stop position on each of the plurality of branch tracks to start toward the first main track for each of the plurality of branch tracks; In the start control, the start of at least one of the transport vehicles stopped at each stop position of the plurality of branch tracks is prohibited depending on the presence or absence of the transport vehicle in a predetermined section on the track. <Invention 2> the orbit has a second main orbit; the stopping position corresponds to a loading port for loading the transport vehicle; The plurality of branch tracks are connected to the second main track via different branch points, the predetermined section includes a first section that is a section upstream of a stop position on each of the plurality of branch tracks, In the starting control, A conveying system as described in invention 1, wherein when there is no conveying vehicle in the first section of one of the branch tracks, and when there is no conveying vehicle that is scheduled to enter the first section from the second main track, the conveying vehicle stopped at a stopping position of one of the branch tracks is prohibited from departing. <Invention 3> In the first section, an unloading port for unloading the transport vehicle is arranged along the track, In the starting control, A conveying system as described in Invention 2, wherein when there is no conveying vehicle that has unloaded at the unloading port in the first section of one of the branch tracks, the conveying vehicle stopped at a stopping position of one of the branch tracks is prohibited from departing. <Invention 4> the predetermined section includes a second section that is a section on the track from the stopping positions of the plurality of branch tracks to the most downstream junction, In the starting control, A conveying system as described in any one of inventions 1 to 3, wherein the departure of all of the conveying vehicles stopped at the respective stopping positions of the plurality of branch tracks is prohibited when other conveying vehicles other than the conveying vehicle in question are present in the second section. <Invention 5> In the starting control, causing each of the transport vehicles stopped at a stop position on each of the plurality of branch tracks to start at a timing that is repeated at a constant cycle for each of the plurality of branch tracks; 5. The transport system according to any one of claims 1 to 4, wherein for the transport vehicle that has been prohibited from starting in a certain cycle, it is determined again whether or not to prohibit the transport vehicle from starting in the next cycle. <Invention 6> 6. The transport system according to claim 5, wherein the start control allows the transport vehicle that has been prohibited from starting for a predetermined period to start in the next period. [Explanation of symbols]

[0056] 1...transport system, 3...track, 4...delivery port, 10, 10a, 10b, 10X...transport vehicle, 20...controller, 31...main track (first main track), 32...main track (second main track), 33a-33d...first branch track (branch track), 34a-34d...second branch track, 35a-35d...junction point, 36a-36d...branch point, 41...unloading port, 42...loading port, L...cargo, R...specific section, Z...predetermined section, Z1...first section, Z2...second section.

Claims

1. a plurality of transport vehicles that travel along a track and transport loads; A controller that controls the travel of the plurality of transport vehicles, The track includes a first main track and a plurality of branch tracks that connect to the first main track via different junctions, the controller executes a start control to cause each of the guided vehicles stopped at a stop position on each of the plurality of branch tracks to start toward the first main track for each of the plurality of branch tracks; the start control prohibits the start of at least one of the transporting vehicles stopped at each stop position of the plurality of branch tracks depending on the presence or absence of the transporting vehicle in a predetermined section on the track; the orbit has a second main orbit; the stopping position corresponds to a loading port for loading the transport vehicle; the second main track branches into a plurality of branch tracks at different branch points, the predetermined section includes a first section that is a section upstream of a stop position on each of the plurality of branch tracks, In the starting control, A conveying system that prohibits a conveying vehicle stopped at a stopping position on one of the branch tracks from departing when the conveying vehicle is not present in the first section of one of the branch tracks and when the conveying vehicle that is scheduled to enter the first section from the second main track is not present.

2. In the first section, an unloading port for unloading the transport vehicle is arranged along the track, In the starting control, 2. The conveying system according to claim 1, wherein when there is no conveying vehicle that has unloaded at the unloading port in the first section of one of the branch tracks, the conveying vehicle stopped at a stopping position of one of the branch tracks is prohibited from departing.

3. A plurality of transport vehicles that travel along a track and transport loads; A controller that controls the travel of the plurality of transport vehicles, The track includes a first main track and a plurality of branch tracks that connect to the first main track via different junctions, the controller executes a start control to cause each of the guided vehicles stopped at a stop position on each of the plurality of branch tracks to start toward the first main track for each of the plurality of branch tracks; the start control prohibits the start of at least one of the transporting vehicles stopped at each stop position of the plurality of branch tracks depending on the presence or absence of the transporting vehicle in a predetermined section on the track; the predetermined section includes a second section that is a section on the track from stop positions of the plurality of branch tracks to the most downstream junction, In the starting control, A conveyance system in which all of the conveyance vehicles stopped at the respective stopping positions of the plurality of branch tracks are prohibited from departing when other conveyance vehicles other than the concerned conveyance vehicle are present in the second section.

4. A plurality of transport vehicles that travel along a track and transport loads; A controller that controls the travel of the plurality of transport vehicles, The track includes a first main track and a plurality of branch tracks that connect to the first main track via different junctions, the controller executes a start control to cause each of the guided vehicles stopped at a stop position on each of the plurality of branch tracks to start toward the first main track for each of the plurality of branch tracks; the start control prohibits the start of at least one of the transporting vehicles stopped at each stop position of the plurality of branch tracks depending on the presence or absence of the transporting vehicle in a predetermined section on the track; In the starting control, causing each of the transport vehicles stopped at a stop position on each of the plurality of branch tracks to start at a timing that is repeated at a constant cycle for each of the plurality of branch tracks; The transportation system determines again whether or not the transportation vehicle that has been prohibited from starting in a certain period should be prohibited from starting in the next period.

5. 5. The transport system according to claim 4, wherein the start control allows the transport vehicle that has been prohibited from starting for a predetermined period to start in the next period.

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