Overhead transport vehicle and overhead transport vehicle system

Abstract

To provide an overhead carrier and an overhead carrier system capable of reducing time and effort for adjustment necessary for determining the presence or absence of an article already placed on a placement part to be transferred.SOLUTION: The ceiling transport vehicle 1 travels along the track 20 and transports an article 30. The ceiling transport vehicle 1 includes the transport vehicle controller 8 that controls the operation of the ceiling transport vehicle 1, the camera 9 that sets the plurality of shelf parts T in the imaging range R, and the determiner 10 that determines the presence or absence of the article 30 already placed on the shelf part T based on the imaging result of the camera 9 when the article 30 is transferred to and from the shelf part T.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] One aspect of the present invention relates to an overhead transport vehicle and an overhead transport vehicle system. [Background technology]

[0002] As a technology relating to an overhead transport vehicle that travels along a track and transports items, for example, the transport vehicle described in Patent Document 1 is known. In the transport vehicle described in Patent Document 1, when an item is placed on a buffer (placement unit) provided along the travel path and near a processing device, a sensor detects the item already placed on the buffer. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2006-290291 Summary of the Invention [Problem to be solved by the invention]

[0004] In the above-described technology, when transferring an article between multiple placement sections that are located at different horizontal positions relative to the overhead transport vehicle, it is difficult for a single sensor to determine whether an article has been placed on each placement section, so a sensor is provided on the overhead transport vehicle for each placement section. In this case, adjustments to each sensor are required, which can be time-consuming.

[0005] An object of one aspect of the present invention is to provide an overhead transport vehicle and an overhead transport vehicle system that can reduce the effort required for adjustments required to determine whether or not an item has been placed on a placement section. [Means for solving the problem]

[0006] (1) An overhead transport vehicle according to one aspect of the present invention is a ceiling transport vehicle that travels along a track and transports items, and is equipped with a control unit that controls the operation of the ceiling transport vehicle, an imaging unit that captures multiple loading sections within an imaging range, and a determination unit that, when transferring items between loading sections, determines whether or not an item has already been placed on the loading section to be transferred based on the imaging results of the imaging unit.

[0007] In this ceiling transport vehicle, since multiple placement sections are accommodated within the imaging range of the imaging unit, when transferring an item to one of these placement sections, the presence or absence of an item already placed on the placement section (hereinafter simply referred to as "placed item") can be determined based on the imaging results, reducing the need to provide a sensor for each placement section. This makes it possible to reduce the effort required for adjustments to determine the presence or absence of placed items.

[0008] (2) In the ceiling transport vehicle described in (1) above, when transferring an item between the control unit and the placement unit, the control unit may notify the determination unit of the placement unit to which the item is to be transferred, and the determination unit may determine the presence or absence of an item on the placement unit to which the item is to be transferred, based on the image capture result of the imaging unit. In this case, the presence or absence of an item already placed can be determined using the notification from the control unit.

[0009] (3) In the overhead transport vehicle described in (1) or (2) above, when an item is unloaded onto the loading section, the determining unit may determine whether or not there is a pre-loaded item, which is an item that has already been placed on the loading section at the unloading destination, based on the image capture result of the imaging unit. In this case, it is possible to reduce the effort required for adjustments required to determine whether or not there is a pre-loaded item when unloading.

[0010] (4) In the overhead transport vehicle described in any one of (1) to (3) above, the determination unit may store a learning model that outputs output data regarding the presence or absence of an item already placed on the placement section of the transfer target by receiving as input data at least an image captured by the imaging unit and including an area corresponding to the placement section of the transfer target, and determine the presence or absence of an item already placed on the placement section of the transfer target based on the imaging result of the imaging unit and the learning model. This makes it possible to determine the presence or absence of an item already placed using the learning model.

[0011] (5) The overhead transport vehicle described in (4) above may be an overhead transport vehicle that transports multiple types of articles with different appearances, and the learning model may output output data regarding the presence or absence of multiple types of articles already placed on the placement section to be transferred. This makes it possible to determine the presence or absence of an article already placed even when multiple types of articles with different appearances are mixed.

[0012] (6) In the overhead transport vehicle described in any one of (1) to (5) above, the determination unit may be included in the imaging unit, and the control unit may acquire only the determination result of whether or not an article has been placed on the placement unit to be transferred from the determination unit included in the imaging unit, and control the operation of the overhead transport vehicle based on the determination result. In this case, since the image captured by the imaging unit is not output from the imaging unit, it is possible to ensure security regarding the image.

[0013] (7) An overhead transport vehicle system according to one aspect of the present invention includes the overhead transport vehicle according to any one of (1) to (6) above and a plurality of placement units arranged around the track. This overhead transport vehicle system can place items on the placement units arranged around the track, and even in this case, can achieve the above-mentioned advantageous effect of reducing the effort required for adjustments to determine whether or not an item has been placed.

[0014] (8) In the ceiling transport vehicle system described in (7) above, the plurality of placement sections may include a first placement section disposed at least on one side or the other side of the track in a horizontal direction intersecting the direction in which the track extends, and a second placement section disposed directly below the track, and the imaging section may include the first placement section and the second placement section within its imaging range when transferring an item between the first placement section and the second placement section. This allows items to be placed on the first placement section and the second placement section, and even in this case, the above-mentioned advantageous effect of reducing the effort required for adjustments to determine whether or not an item has been placed can be achieved.

[0015] (9) In the ceiling transport vehicle system described in (7) or (8) above, the plurality of mounts may be arranged at least either on one side or the other side of the track in a horizontal direction intersecting the direction in which the track extends, and may include a third mount that is below the first mount and spaced apart in the direction in which the track extends, and the imaging unit may include the third mount within its imaging range when transferring an item between the first mount and the third mount. This allows an item to be placed on the third mount, and even in that case, the above-mentioned advantageous effect of reducing the effort required for adjustments to determine whether an item has been placed can be achieved.

[0016] (10) In the overhead transport vehicle system described in any one of (7) to (9) above, the track may include a first track and a second track disposed below the first track, and the overhead transport vehicles traveling on the first and second tracks may transfer articles to and from the third mount section. This allows both the overhead transport vehicle traveling on the first track and the overhead transport vehicle traveling on the second track to transfer articles to and from the third mount section, enabling articles to be handed over between overhead transport vehicles traveling on different tracks via the third mount section. Even in this case, the above-described advantageous effect can be achieved, which reduces the effort required for adjustments required to determine whether or not an article has been placed on both the overhead transport vehicles traveling on the first track and the second track. [Effects of the Invention]

[0017] According to the present invention, it is possible to provide an overhead transport vehicle and an overhead transport vehicle system that can reduce the effort required for adjustments required to determine whether or not an article has been placed on a placement section. [Brief explanation of the drawings]

[0018] [Figure 1] FIG. 1 is a side view showing the ceiling transport vehicle system according to the first embodiment. [Figure 2] Fig. 2(a) is a rear view showing the ceiling transport vehicle system of Fig. 1. Fig. 2(b) is another rear view showing the ceiling transport vehicle system of Fig. 1. [Figure 3]Fig. 3(a) is a rear view illustrating the operation of the ceiling transport vehicle of Fig. 1. Fig. 3(b) is a rear view illustrating another operation of the ceiling transport vehicle of Fig. 1. Fig. 3(c) is a rear view illustrating yet another operation of the ceiling transport vehicle of Fig. 1. [Figure 4] FIG. 4 is a block diagram showing a transport vehicle controller and a camera of the overhead transport vehicle system of FIG. [Figure 5] Fig. 5(a) is a rear view showing the ceiling transport vehicle system according to the second embodiment, and Fig. 5(b) is another rear view showing the ceiling transport vehicle system of Fig. 5(a). [Figure 6] Fig. 6(a) is a rear view showing the ceiling transport vehicle system according to the third embodiment, and Fig. 6(b) is another rear view showing the ceiling transport vehicle system of Fig. 6(a). [Figure 7] FIG. 7 is a rear view showing the ceiling transport vehicle system according to the fourth embodiment. [Figure 8] Fig. 8(a) is a rear view showing the ceiling transport vehicle system according to the fifth embodiment, and Fig. 8(b) is another rear view showing the ceiling transport vehicle system of Fig. 8(a). [Figure 9] FIG. 9 is a block diagram showing a transport vehicle controller and a camera of the ceiling transport vehicle system according to the sixth embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0019] Hereinafter, the embodiments will be described in detail with reference to the drawings. The same or equivalent elements are designated by the same reference numerals, and redundant explanations will be omitted.

[0020] [First embodiment] As shown in FIG. 1, the overhead transport vehicle system 100 according to the first embodiment is a system for transporting an item 30 using an overhead transport vehicle 1 that is movable along a track 20. The item 30 is, for example, a FOUP (Front Opening Unified Pod) that houses multiple semiconductor wafers. The item 30 may also be a container that stores multiple semiconductor wafers, a container that stores glass substrates, a reticle pod, a general part, or the like. Hereinafter, the terms "upper" and "lower" correspond to the vertical direction, the terms "front" and "rear" correspond to the forward and backward directions in the traveling direction of the overhead transport vehicle 1, and the terms "left" and "right" correspond to the left and right directions of the overhead transport vehicle 1.

[0021] The overhead transport vehicle system 100 includes a track 20 and an overhead transport vehicle 1. The track 20 is installed near the ceiling of a clean room where semiconductor devices are manufactured. The track 20 is suspended and supported by, for example, supports. The track 20 forms a travel path for the overhead transport vehicle 1.

[0022] The overhead transport vehicle 1 travels along a track 20 and transports an article 30. The overhead transport vehicle 1 includes a frame unit 2, a traveling unit 3, a lateral unit 4, a theta unit 5, a lifting drive unit 6, a holding unit 7, and a transport vehicle controller (control unit) 8. The frame unit 2 has a center frame 15, a front frame 16, and a rear frame 17. The front frame 16 extends downward from the front end of the center frame 15. The rear frame 17 extends downward from the rear end of the center frame 15.

[0023] The traveling unit 3 is disposed above the center frame 15. The traveling unit 3 travels along the track 20 by, for example, receiving a contactless supply of power from a high-frequency current line laid along the track 20. The lateral unit 4 is disposed below the center frame 15. The lateral unit 4 moves the theta unit 5, the lifting drive unit 6, and the holding unit 7 laterally (to the side, left and right in the traveling direction of the ceiling transport vehicle 1). The theta unit 5 is disposed below the lateral unit 4. The theta unit 5 rotates the lifting drive unit 6 and the holding unit 7 within a horizontal plane.

[0024] The lifting drive unit 6 is disposed below the theta unit 5. The lifting drive unit 6 lifts and lowers the holding unit 7. The lifting drive unit 6 lifts and lowers the holding unit 7 by winding or unwinding a belt B connected to the holding unit 7. The holding unit 7 is provided so that it can be raised and lowered. The holding unit 7 is disposed below the lifting drive unit 6. The holding unit 7 is suspended by a plurality of belts B. The holding unit 7 lifts and lowers by winding or unwinding the belts B by the lifting drive unit 6. The holding unit 7 holds (grabs) a flange 31 of the article 30. The holding unit 7 has a pair of grippers 12, 12. The pair of grippers 12, 12 are opened and closed by, for example, a drive motor and a link mechanism.

[0025] The transport vehicle controller 8 is disposed, for example, on the center frame 15. The transport vehicle controller 8 is an electronic control unit configured with a CPU (Central Processing Unit), a ROM (Read only memory), a RAM (Random access memory), etc. The transport vehicle controller 8 controls the operation of the overhead transport vehicle 1. The transport vehicle controller 8 causes the overhead transport vehicle 1 to transport the article 30 based on a transport command assigned from a higher-level controller such as an area controller.

[0026] As shown in Figures 2(a) and 2(b), in the ceiling transport vehicle system 100, the track 20 has a first track 21 and a second track 22 arranged below the first track 21. In the example shown, the second track 22 is arranged so as to be located directly below the first track 21. The ceiling transport vehicle system 100 is equipped with an upper storage shelf 40 and a lower storage shelf 50. The upper storage shelf 40 and the lower storage shelf 50 temporarily store items 30. The upper storage shelf 40 is arranged along the first track 21. The lower storage shelf 50 is arranged along the second track 22. The upper storage shelf 40 and the lower storage shelf 50 are arranged spaced apart from each other in a direction along the track 20. Each of the upper storage shelf 40 and the lower storage shelf 50 has a plurality of shelf sections (mounting sections) T on which the items 30 are placed. The shelf T is arranged around the first track 21 and the second track 22, and is suspended directly or indirectly from the ceiling, for example. The shelf T is an overhead buffer (OHB).

[0027] As shown in FIG. 2(a), the upper storage shelf 40 includes a left shelf portion 41, a right shelf portion 42, and a lower shelf portion 43 as shelf portions T. The left shelf portion 41, the right shelf portion 42, and the lower shelf portion 43 are arranged side by side in the left-right direction. The left shelf portion 41 is arranged to the left of the first track 21 (one side in the horizontal direction intersecting with the extension direction of the first track 21). The right shelf portion 42 is arranged to the right of the first track 21 (the other side in the horizontal direction intersecting with the extension direction of the first track 21). The left shelf portion 41 and the right shelf portion 42 are arranged at the same height. The lower shelf portion 43 is arranged directly below the first track 21. The lower shelf portion 43 is arranged lower than the left shelf portion 41 and the right shelf portion 42. The left shelf portion 41 and the right shelf portion 42 form a side track buffer (STB) and constitute a first placement portion. The lower shelf 43 is an under-track buffer (UTB) and constitutes a second mounting section.

[0028] As shown in FIG. 2(b), the lower storage shelf 50 includes a left shelf portion 51, a right shelf portion 52, and a lower shelf portion 53 as shelf portion T. The left shelf portion 51, the right shelf portion 52, and the lower shelf portion 53 are arranged side by side in the left-right direction. The left shelf portion 51, the right shelf portion 52, and the lower shelf portion 53 are arranged below the left shelf portion 41, the right shelf portion 42, and the lower shelf portion 43 and spaced apart in the extension direction of the second track 22. The left shelf portion 51 is arranged to the left of the second track 22. The right shelf portion 52 is arranged to the right of the second track 22. The left shelf portion 51 and the right shelf portion 52 are arranged at the same height. The lower shelf portion 53 is arranged directly below the second track 22. The lower shelf portion 53 is arranged below the left shelf portion 51 and the right shelf portion 52. The left shelf 51 and the right shelf 52 are side track buffers and constitute a third mount, and the lower shelf 53 is an under track buffer and constitutes a fourth mount.

[0029] In the overhead transport vehicle system 100, the overhead transport vehicle 1 traveling on the first track 21 and the second track 22 operates, for example, as follows. When a transport command to unload (transfer) the article 30 from the overhead transport vehicle 1 to the lower shelf 43 is assigned to the overhead transport vehicle 1 traveling on the first track 21, the overhead transport vehicle 1 first travels to a position directly above the lower shelf 43 and stops. As shown in FIG. 3( a), at the stopped position, the overhead transport vehicle 1 lowers the holding unit 7 using the lifting drive unit 6, places the article 30 on the lower shelf 43, and releases the holding unit 7 from its hold. Thereafter, the overhead transport vehicle 1 returns the holding unit 7 to its initial position using the lifting drive unit 6. Note that the overhead transport vehicle 1 traveling on the second track 22 and holding the article 30 performs a similar operation when unloading the article 30 onto the lower shelf 53.

[0030] When an overhead transport vehicle 1 traveling on the first track 21 and not holding an article 30 is assigned a transport command to load (transfer) an article 30 from the lower shelf section 43 or the lower shelf section 53 onto the overhead transport vehicle 1, the overhead transport vehicle 1 first travels to a position directly above the lower shelf section 43 and stops. At this stopped position, the overhead transport vehicle 1 lowers the holding unit 7 by driving the lifting drive unit 6, and the holding unit 7 holds the article 30 placed on the lower shelf section 43. The overhead transport vehicle 1 then returns the holding unit 7 to its initial position by driving the lifting drive unit 6. Note that an overhead transport vehicle 1 traveling on the second track 22 and not holding an article 30 performs a similar operation to the above when loading an article 30 from the lower shelf section 53 onto the overhead transport vehicle 1.

[0031] Furthermore, when the overhead transport vehicle 1 traveling on the first track 21 and holding the article 30 receives a transport command to unload the article 30 onto the left shelf 41, the overhead transport vehicle 1 first travels to the side of the left shelf 41 in a plan view and stops. As shown in FIG. 3(b), the overhead transport vehicle 1, at its stopped position, moves the holding unit 7 to the left by driving the lateral unit 4, and positions the holding unit 7 directly above the left shelf 41. The overhead transport vehicle 1 lowers the holding unit 7 by driving the lifting drive unit 6, places the article 30 on the left shelf 41, and releases the holding unit 7 from its hold. Thereafter, the overhead transport vehicle 1 returns the holding unit 7 to its initial position by driving the lateral unit 4 and the lifting drive unit 6. Note that the overhead transport vehicle 1 traveling on the second track 22 and holding the article 30 performs a similar operation when unloading the article 30 onto the left shelf 51.

[0032] When a transport command is assigned to the overhead transport vehicle 1 traveling on the first track 21 and not holding an article 30 to load an article 30 from the left shelf 41 onto the overhead transport vehicle 1, the overhead transport vehicle 1 first travels to the side of the left shelf 41 in a plan view and stops. At this stopped position, the overhead transport vehicle 1 drives the lateral unit 4 to move the holding unit 7 to the left, positioning the holding unit 7 directly above the left shelf 41. The overhead transport vehicle 1 drives the lifting drive unit 6 to lower the holding unit 7, and the holding unit 7 holds the article 30 placed on the left shelf 41. The overhead transport vehicle 1 then drives the lateral unit 4 and the lifting drive unit 6 to return the holding unit 7 to its initial position. Note that the overhead transport vehicle 1 traveling on the second track 22 and not holding an article 30 performs a similar operation when loading an article 30 from the left shelf 51 onto the overhead transport vehicle 1.

[0033] Furthermore, when a transport command is assigned from the ceiling transport vehicle 1 to the right shelf 42, or when a transport command is assigned from the right shelf 42 to the ceiling transport vehicle 1, the ceiling transport vehicle 1 traveling on the first track 21 operates in the same manner as described above to unload and load the article 30 between the left shelf 41 (see FIG. 3(c)). Note that the ceiling transport vehicle 1 traveling on the second track 22 performs the same operation when unloading the article 30 from the ceiling transport vehicle 1 to the right shelf 52, and when loading the article 30 from the right shelf 52 to the ceiling transport vehicle 1.

[0034] Next, the main parts of the ceiling transport vehicle 1 of this embodiment will be described.

[0035] As shown in Figures 1, 2(a) and 2(b), the ceiling transport vehicle 1 is equipped with a camera (imaging unit) 9 that captures multiple shelf sections T within an imaging range R. The camera 9 is provided, for example, on the front frame 16. The camera 9 is attached so that its imaging range R faces downward of the ceiling transport vehicle 1. The camera 9 may be provided anywhere on the ceiling transport vehicle 1 other than a location that operates when driven by the lateral unit 4. The camera 9 is a wide-angle camera that has a wide-angle lens with a wide angle of view.

[0036] The camera 9 is installed so that when unloading articles 30 onto the upper storage shelf 40 or loading articles 30 from the upper storage shelf 40, all of the left shelf portion 41, right shelf portion 42, and lower shelf portion 43 fall within the imaging range R. The camera 9 is installed so that when unloading articles 30 onto the lower storage shelf 50 or loading articles 30 from the lower storage shelf 50, all of the left shelf portion 51, right shelf portion 52, and lower shelf portion 53 fall within the imaging range R.

[0037] As shown in FIG. 4, the ceiling transport vehicle 1 includes a determination unit 10. When transferring an item 30 between a shelf unit T and the shelf unit T, the determination unit 10 determines whether or not an item 30 has already been placed on the shelf unit T to be transferred, based on an image acquired by a camera 9 (the image captured by the camera 9, also referred to as a "camera image"). When unloading an item 30 onto the shelf unit T, the determination unit 10 determines, based on the camera image, whether or not there is a pre-loaded item, i.e., an item 30, already placed on the shelf unit T at the unloading destination. When loading an item 30 from the shelf unit T, the determination unit 10 determines, based on the camera image, whether or not there is an item 30 already placed on the shelf unit T from which the item is to be loaded.

[0038] When transferring an item 30 between the transport vehicle controller 8 and the shelf section T, the transport vehicle controller 8 notifies the determination unit 10 of the camera 9 of the shelf section T to be transferred. Here, the transport vehicle controller 8 notifies the determination unit 10 of the shelf section T to be transferred, by sending shelf section position information regarding the position of the shelf section T to be transferred. The shelf section position information of the shelf section T may be, for example, position information of the shelf section T based on the stopping position of the ceiling transport vehicle 1. The shelf section position information of the shelf section T may be, for example, information regarding the coordinates and size of the shelf section T in the camera image. The shelf section position information of the shelf section T can be acquired from the assigned transport command.

[0039] The determination unit 10 determines, based on the camera image, whether or not there is an item 30 on the shelf unit T to be transferred that has been notified by the transport vehicle controller 8. Specifically, the determination unit 10 determines, based on the camera image, shelf unit position information of the shelf unit T to be transferred, and a learning model M that is a trained machine learning model, whether or not there is an item 30 already placed on the shelf unit T to be transferred. The determination unit 10 is included in, for example, an electronic control unit of the camera 9. In other words, the camera 9 is an AI camera equipped with AI (artificial intelligence) that determines whether or not there is an item 30 already placed on the shelf unit T to be transferred.

[0040] The learning model M is generated in advance and stored in, for example, an electronic control unit of the camera 9. The learning model M is a trained model that receives a camera image and shelf position information of the shelf T to be transferred as input data, and outputs output data regarding the presence or absence of an item 30 already placed on the shelf T to be transferred. The learning model M may be generated, for example, by using a data set including multiple "pairs of a camera image, shelf position information of the shelf T to be transferred, and the presence or absence of an item 30 already placed on the shelf T to be transferred in the camera image" as training data.

[0041] For example, when transferring an item 30 between the left shelf section 41 and the left shelf section 41, the learning model M receives a camera image and shelf section position information of the left shelf section 41, and outputs output data regarding the presence or absence of an item 30 placed on the left shelf section 41. Similarly, when transferring an item 30 between the right shelf section 42, the lower shelf section 43, the left shelf section 51, the right shelf section 52, and the lower shelf section 53, the learning model M receives a camera image and shelf section position information of the shelf section, and outputs output data regarding the presence or absence of an item 30 placed on any of the shelf sections.

[0042] There is no particular limitation on the algorithm used in such a learning model M. The learning model M may be, for example, a neural network model, a linear regression model, or a random forest model. The neural network model may be a deep learning model with multiple intermediate layers.

[0043] The determination unit 10 outputs only the determination result of whether or not an item 30 has already been placed on the shelf unit T to be transferred to the transport vehicle controller 8. The transport vehicle controller 8 acquires only the determination result of whether or not an item 30 has already been placed on the shelf unit T to be transferred from the determination unit 10, and controls the operation of the ceiling transport vehicle 1 based on the determination result.

[0044] In the overhead transport vehicle 1 described above, for example, when unloading items 30 onto a shelf T, a camera image of multiple shelf sections T is captured by the camera 9. At the same time, shelf section position information of the shelf section T at the unloading destination is output from the transport vehicle controller 8 to the camera 9. The determination section 10 of the camera 9 uses a learning model M to determine whether or not there are pre-loaded items on the shelf section T at the unloading destination, based on the camera image and the shelf section position information of the shelf section T at the unloading destination. The determination result is output from the determination section 10 to the transport vehicle controller 8. When the transport vehicle controller 8 receives a determination result from the determination section 10 that "pre-loaded items are present," it suspends unloading and notifies the upper controller of this fact. When the transport vehicle controller 8 receives a determination result from the determination section 10 that "pre-loaded items are not present," it executes unloading.

[0045] Furthermore, in the ceiling transport vehicle 1, for example, when loading items 30 from a shelf T, a camera image containing multiple shelf sections T is captured by the camera 9. At the same time, shelf section position information of the shelf section T at the loading source is output from the transport vehicle controller 8 to the camera 9. The determination section 10 of the camera 9 uses the learning model M to determine whether or not an item 30 has already been placed on the shelf section T at the loading source, based on the camera image and the shelf section position information of the shelf section T at the loading source. The determination result is output from the determination section 10 to the transport vehicle controller 8. When the transport vehicle controller 8 receives a determination result from the determination section 10 that "items 30 have already been placed," it executes loading. When the transport vehicle controller 8 receives a determination result from the determination section 10 that "items 30 have not already been placed," it suspends loading and notifies the upper controller of that effect.

[0046] As described above, in the ceiling transport vehicle 1, multiple shelf sections T are contained within the imaging range R of the camera 9. Therefore, when transferring an item 30 to one of these multiple shelf sections T, the presence or absence of an item 30 already placed on the shelf section T to be transferred can be determined based on the camera image of the camera 9, reducing the need to provide a sensor for each position on the shelf section T. This reduces the effort required for adjustments such as adjusting the optical axis of the sensor, and makes it possible to reduce the effort required for adjustments when determining the presence or absence of an item 30 already placed on the shelf section T. Furthermore, by basing the determination on the camera image, the determination of the presence or absence of the item 30 is less susceptible to the adverse effect of the distance between the track 20 and the shelf section T compared to when it is based on the detection results of the sensor, making it possible to increase the robustness of the determination result.

[0047] In the ceiling transport vehicle 1, when transferring an item 30 between the transport vehicle controller 8 and a shelf section T, the transport vehicle controller 8 notifies the determination unit 10 of the shelf section T to be transferred. The determination unit 10 determines whether or not the item 30 is present on the shelf section T to be transferred, which has been notified by the transport vehicle controller 8, based on the camera image. In this case, the notification from the transport vehicle controller 8 can be used to determine whether or not the item 30 has already been placed on the shelf section T to be transferred.

[0048] In the ceiling transport vehicle 1, the determination unit 10 may determine the presence or absence of pre-loaded items based on camera images when unloading the items 30 onto the shelf unit T. In this case, it is possible to reduce the effort required for adjustments required to determine the presence or absence of pre-loaded items when unloading.

[0049] In the ceiling transport vehicle 1, the determination unit 10 stores the learning model M and determines whether or not an item 30 has already been placed on the shelf section T to be transferred based on the camera image and the learning model M. In this way, the learning model M can be used to determine whether or not an item 30 has already been placed on the shelf section T to be transferred.

[0050] In the ceiling transport vehicle 1, the determination unit 10 is included in the camera 9. The transport vehicle controller 8 acquires only the determination result of whether or not an item 30 has already been placed on the shelf section T to be transferred from the determination unit 10. The transport vehicle controller 8 controls the operation of the ceiling transport vehicle 1 based on the determination result. In this case, since the camera image is not output from the camera 9, it is possible to ensure security regarding the camera image.

[0051] The ceiling transport vehicle system 100 includes an ceiling transport vehicle 1 and a plurality of shelves T arranged around a track 20. In the ceiling transport vehicle system 100, an item 30 can be placed on the shelves T arranged around the track 20, and even in this case, the above-mentioned effect of being able to reduce the effort required for adjustments when determining whether or not an item 30 has already been placed on the shelves T can be achieved.

[0052] In the ceiling transport vehicle system 100, the multiple shelf sections T include a left shelf section 41, a right shelf section 42, and a lower shelf section 43. When transferring an item 30 between the left shelf section 41, the right shelf section 42, and the lower shelf section 43, the camera 9 includes all of the left shelf section 41, the right shelf section 42, and the lower shelf section 43 within the imaging range R. This allows the item 30 to be placed on the left shelf section 41, the right shelf section 42, and the lower shelf section 43, and even in this case, the above-mentioned advantageous effect of being able to reduce the effort required for adjustments when determining whether or not an item 30 has already been placed on the shelf section T can be achieved.

[0053] In the ceiling transport vehicle system 100, the multiple shelf sections T include a left shelf section 51, a right shelf section 52, and a lower shelf section 53. When transferring an item 30 between the left shelf section 51, the right shelf section 52, and the lower shelf section 53, the camera 9 includes all of the left shelf section 51, the right shelf section 52, and the lower shelf section 53 within the imaging range R. This allows the item 30 to be placed on the left shelf section 51, the right shelf section 52, and the lower shelf section 53, and even in this case, the above-mentioned advantageous effect of being able to reduce the effort required for adjustments when determining whether or not an item 30 has already been placed on the shelf section T can be achieved.

[0054] In the overhead transport vehicle system 100, the track 20 includes a first track 21 and a second track 22. The overhead transport vehicles 1 traveling on the first track 21 and the second track 22 transfer articles 30 between the left shelf section 51 and the right shelf section 52. As a result, the overhead transport vehicles 1 traveling on the first track 21 and the overhead transport vehicles 1 traveling on the second track 22 can both transfer articles between the left shelf section 51 and the right shelf section 52, so that articles 30 can be handed over between the overhead transport vehicles 1 traveling on different tracks 20 via the left shelf section 51 and the right shelf section 52. Even in this case, the above-mentioned advantageous effect can be achieved, that is, the effort required for adjustments required to determine whether or not an article 30 has been placed on the shelf section T can be reduced in both the overhead transport vehicles 1 traveling on the first track 21 and the second track 22.

[0055] The ceiling transport vehicle 1 of this embodiment may transport multiple types of articles 30 having different appearances. In this case, the learning model M outputs output data regarding the presence or absence of multiple types of articles 30 already placed on the shelf section T to be transferred. This provides the effect of determining the presence or absence of an article 30 already placed on the shelf section T even when multiple types of articles 30 having different appearances are mixed together.

[0056] [Second embodiment] Next, a second embodiment will be described. In the description of this embodiment, differences from the first embodiment will be described, and overlapping descriptions will be omitted.

[0057] As shown in Figures 5(a) and 5(b), the ceiling transport vehicle system 200 of the second embodiment differs from the first embodiment in that the track 20 is only the first track 21. As shown in Figure 5(a), the ceiling transport vehicle 1 that has traveled along the first track 21 and stopped can transfer articles 30 between the upper storage shelf 40 (left shelf portion 41, right shelf portion 42, and lower shelf portion 43). The camera 9 is installed so that all of the left shelf portion 41, right shelf portion 42, and lower shelf portion 43 fall within the imaging range R when the ceiling transport vehicle 1 that has stopped on the first track 21 unloads articles 30 onto the upper storage shelf 40 or loads articles 30 from the upper storage shelf 40.

[0058] 5(b), the ceiling transport vehicle 1 that has traveled along the first track 21 and stopped can transfer articles 30 between the lower storage shelf 50 (left shelf portion 51, right shelf portion 52, and lower shelf portion 53). The camera 9 is installed so that all of the left shelf portion 51, right shelf portion 52, and lower shelf portion 53 fall within the imaging range R when the ceiling transport vehicle 1 that has stopped on the first track 21 unloads articles 30 onto the lower storage shelf 50 or loads articles 30 from the lower storage shelf 50.

[0059] As described above, in this embodiment as well, it is possible to reduce the effort required for adjustments when determining whether or not an item 30 has already been placed on a shelf section T. Furthermore, in the ceiling transport vehicle system 200, the track 20 has only the first track 21. This allows items 30 to be placed on shelf sections T arranged around the first track 21, and even in this case, the above-mentioned advantageous effect of reducing the effort required for adjustments when determining whether or not an item 30 has already been placed on a shelf section T can be achieved.

[0060] [Third embodiment] Next, a third embodiment will be described. In the description of this embodiment, differences from the first embodiment will be described, and overlapping descriptions will be omitted.

[0061] As shown in Figures 6(a) and 6(b), the ceiling transport vehicle system 300 of the third embodiment differs from the first embodiment in that it is equipped with sensors 301 and 302 for detecting the item 30, and is equipped with a camera 309 instead of the camera 9 (see Figure 2(a)).

[0062] The sensors 301 and 302 are sensors that emit directional detection light. The sensors 301 and 302 detect the article 30 by receiving the detection light reflected by a reflector (not shown) provided on the article 30. The sensors 301 and 302 are provided, for example, on the rear frame 17. The sensors 301 and 302 may be provided anywhere on the ceiling transport vehicle 1 other than a location that operates when the lateral unit 4 is driven.

[0063] As shown in Figure 6(a), the sensor 301 detects the item 30 placed on the left shelf section 41 when the ceiling transport vehicle 1 unloads the item 30 onto the left shelf section 41 of the upper storage shelf 40 or loads the item 30 from the left shelf section 41. The sensor 302 detects the item 30 placed on the right shelf section 42 when the ceiling transport vehicle 1 unloads the item 30 onto the right shelf section 42 of the upper storage shelf 40 or loads the item 30 from the right shelf section 42. The sensors 301 and 302 output their detection results to the determination unit 10.

[0064] The camera 309 is a camera with a standard lens having a narrower angle of view than the camera 9. The camera 309 is installed so that when the ceiling transport vehicle 1 unloads articles 30 onto the lower shelf portion 43 of the upper storage shelf 40 or loads articles 30 from the lower shelf portion 43, the lower shelf portion 43 falls within the imaging range R. Furthermore, as shown in FIG. 6(b), the camera 309 is installed so that when the ceiling transport vehicle 1 unloads articles 30 onto the lower storage shelf 50 or loads articles 30 from the lower storage shelf 50, all of the left shelf portion 51, the right shelf portion 52, and the lower shelf portion 53 fall within the imaging range R. In other words, the camera 309 fits multiple shelf portions T within the imaging range R. Except for the above, the camera 309 is configured similarly to the camera 9 (see FIG. 2(a)).

[0065] For example, when transferring an item 30 to or from the left shelf section 41, if the sensor 301 detects the item 30, the determination unit 10 determines that an item 30 has already been placed on the left shelf section 41. For example, when transferring an item 30 to or from the right shelf section 42, if the sensor 301 detects the item 30, the determination unit 10 determines that an item 30 has already been placed on the right shelf section 42. When transferring an item 30 to or from a shelf section T other than the left shelf section 41 and the right shelf section 42, the determination unit 10 uses the learning model M to determine whether or not an item 30 has already been placed on the shelf section T to be transferred, based on the camera image acquired by the camera 309 and the shelf section position information of the shelf section T to be transferred.

[0066] As described above, in this embodiment as well, it is possible to reduce the effort of adjustments required to determine the presence or absence of an article 30 already placed on the shelf section T. Furthermore, since the sensors 301, 302 can ensure sufficient detection accuracy for the article 30 at close range, in this embodiment, the sensors 301, 302 are used to determine the presence or absence of an article 30 on the left shelf section 41 and the right shelf section 42, which are close to the ceiling transport vehicle 1 and unlikely to fit within the imaging range R (angle of view) of the camera 309, and the camera 309 is used to determine the presence or absence of an article 30 on other shelf sections T. In other words, the camera 309 and the sensors 301, 302 can be used in effective combination to determine the presence or absence of an article 30 already placed on the shelf section T.

[0067] [Fourth embodiment] Next, a fourth embodiment will be described. In the description of this embodiment, differences from the first embodiment will be described, and overlapping descriptions will be omitted.

[0068] 7, the ceiling transport vehicle system 400 of the fourth embodiment differs from the first embodiment in that the determination unit 10 determines the presence or absence of an item 30 based on a camera image relating to a portion of the imaging range R. Specifically, the determination unit 10 masks the imaging range R except for the partial range RA corresponding to the shelf section T to be placed on that has been notified by the transport vehicle controller 8. This narrows the imaging range R of the camera image to the partial range RA. The determination unit 10 determines the presence or absence of an item 30 already placed on the shelf section T to be placed on, based on the camera image of the partial range RA and the learning model M.

[0069] The learning model M of this embodiment is a trained model that receives, for example, a camera image of a partial range RA as input data and outputs output data regarding the presence or absence of an item 30 already placed on the shelf section T on which the item is to be placed. The learning model M of this embodiment may be generated, for example, by using, as training data, a data set that includes multiple "pairs of a camera image of a partial range RA and the presence or absence of an item 30 already placed on the shelf section T that is included in the camera image of the partial range RA."

[0070] As described above, in this embodiment as well, it is possible to reduce the effort of adjustments required to determine whether or not an article 30 has been placed on the shelf section T. Furthermore, since the presence or absence of an article 30 placed on the shelf section T is determined based on a camera image limited to a partial range RA, it is possible to improve the accuracy of the determination.

[0071] [Fifth embodiment] Next, a fifth embodiment will be described. In the description of this embodiment, differences from the first embodiment will be described, and overlapping descriptions will be omitted.

[0072] As shown in Figures 8(a) and 8(b), the ceiling transport vehicle system 500 of the fifth embodiment differs from the first embodiment in that it is equipped with a first camera 501 and a second camera 502 instead of the camera 9 (see Figure 2(a)).

[0073] The first camera 501 is provided, for example, on the left side of the front frame 16. The first camera 501 is an imaging unit that includes multiple shelf portions T in its imaging range R1. The first camera 501 acquires a first camera image as a camera image. The second camera 502 is provided, for example, on the right side of the front frame 16. The second camera 502 is an imaging unit that includes multiple shelf portions T in its imaging range R2. The second camera 502 acquires a second camera image as a camera image. The first camera 501 and the second camera 502 are cameras that have standard lenses with a narrower angle of view than the camera 9. The first camera 501 and the second camera 502 constitute an imaging unit.

[0074] The first camera 501 is installed so that when the ceiling transport vehicle 1 unloads articles 30 onto the left shelf portion 41 and the lower shelf portion 43 of the upper storage shelf 40 or loads articles 30 from the left shelf portion 41 and the lower shelf portion 43, at least a portion of the left shelf portion 41 and the lower shelf portion 43 falls within the imaging range R1. The second camera 502 is installed so that when the ceiling transport vehicle 1 unloads articles 30 onto the right shelf portion 42 and the lower shelf portion 43 of the upper storage shelf 40 or loads articles 30 from the right shelf portion 42 and the lower shelf portion 43, at least a portion of the right shelf portion 42 and the lower shelf portion 43 falls within the imaging range R2.

[0075] Furthermore, the first camera 501 is installed so that when the ceiling transport vehicle 1 unloads articles 30 onto the lower storage shelf 50 or loads articles 30 from the lower storage shelf 50, at least a portion of the left shelf portion 51, the right shelf portion 52, and the lower shelf portion 53 fall within an imaging range R1. The second camera 502 is installed so that when the ceiling transport vehicle 1 unloads articles 30 onto the lower storage shelf 50 or loads articles 30 from the lower storage shelf 50, at least a portion of the left shelf portion 51, the right shelf portion 52, and the lower shelf portion 53 fall within an imaging range R2. Except for the above, the first camera 501 and the second camera 502 are configured in the same way as the camera 9 (see FIG. 2(a)).

[0076] The determination unit 10 selects one of the first and second camera images that includes a range corresponding to the shelf section T of the placement target notified by the transport vehicle controller 8. The determination unit 10 determines whether or not an item 30 has already been placed on the shelf section T of the placement target based on either the selected first or second camera image, the shelf section position information of the shelf section T of the placement target, and the learning model M.

[0077] The learning model M of this embodiment is a trained model that receives, as input data, for example, one of the first and second camera images and shelf position information of the shelf T to be placed on, and outputs output data regarding the presence or absence of the item 30 already placed on the shelf T to be placed on. The learning model M of this embodiment may be generated by using, as training data, for example, a data set including a plurality of pairs of the first and second camera images, shelf position information of the shelf T to be transferred, and the presence or absence of the item 30 already placed on the shelf T to be transferred in the first and second camera images.

[0078] As described above, in this embodiment as well, it is possible to reduce the effort required for adjustments required to determine whether or not an article 30 has been placed on the shelf section T. Furthermore, in this embodiment, the ceiling transport vehicle 1 is equipped with the first camera 501 and the second camera 502, which makes it possible to deal with cases where it is difficult to fit multiple shelf sections T within the imaging range of a single camera.

[0079] [Sixth embodiment] Next, a sixth embodiment will be described. In the description of this embodiment, differences from the first embodiment will be described, and overlapping descriptions will be omitted.

[0080] As shown in Figure 9, the ceiling transport vehicle system 600 of the sixth embodiment differs from the first embodiment in that it is equipped with a transport vehicle controller 608 instead of the transport vehicle controller 8 (see Figure 4) and a camera 609 instead of the camera 9 (see Figure 4).

[0081] The transport vehicle controller 608 includes a determination unit 10, but is otherwise configured in the same manner as the transport vehicle controller 8. The camera 609 does not include the determination unit 10, and outputs the acquired camera image to the transport vehicle controller 608. The camera 609 is otherwise configured in the same manner as the camera 9. As described above, in this embodiment as well, it is possible to reduce the effort of adjustments required to determine whether or not an item 30 has been placed on the shelf section T. Note that the object on which the determination unit 10 is implemented is not particularly limited, and the determination unit 10 may be included in an external server, for example.

[0082] [Variations] Although the embodiments have been described above, one aspect of the present invention is not limited to the above-described embodiments, and various modifications are possible without departing from the spirit of the invention.

[0083] In the above embodiment, the determination unit 10 uses a learning model M capable of determining the presence or absence of an article 30 on multiple shelf units T, but this is not limited to this. For example, the determination unit 10 may store multiple learning models capable of determining the presence or absence of an article 30 on one shelf unit T, the number of which is equal to the number of shelf units T, and select and use one of the stored multiple learning models depending on the shelf unit T to be transferred.

[0084] In the above embodiment and modified example, the determination unit 10 determines the presence or absence of the item 30 on the shelf section T to be placed on by using the learning model M, but the present invention is not limited to this. For example, the determination unit 10 may recognize the item 30 and its position on the camera image by performing various image analysis processes such as pattern matching on the camera image, and determine the presence or absence of the item 30 on the shelf section T to be placed on from the recognition result and shelf section position information of the shelf section T to be placed on.

[0085] In the above embodiment and modified example, a mark indicating that no item 30 is placed may be provided on the shelf T in a position hidden by the item 30 placed thereon. When an item 30 is placed on the shelf T, the mark is hidden by the item 30 and does not appear in the camera image, and when no item 30 is placed on the shelf T, the mark appears in the camera image. The shape and type of the mark are not particularly limited, and various marks may be used. When a mark is provided on the shelf T, the learning model M may output data indicating that the mark is present or absent as output data regarding the presence or absence of the item 30.

[0086] In the above embodiment and modified example, a camera with a distance measurement function (such as a stereo camera) may be used as the imaging unit. In this way, when it is determined that an item 30 is present on the shelf T to be placed, the distance to the determined item 30 is calculated, and if the calculated distance is abnormal (for example, if it is clearly too short or too long), it can be verified that the determined item 30 is due to erroneous recognition.

[0087] In the above embodiment and modified example, a camera with a movable lens may be used as the imaging unit. In this case, the entire range of the movable angle of view (i.e., the entire range of possible angles of view) corresponds to the imaging range R. In the above embodiment and modified example, the item 30 is not particularly limited, and may be any object that can be transported by the ceiling transport vehicle 1. In the above embodiment and modified example, the transport vehicle controller 8 is provided as the control unit, but instead of or in addition to this, one or more controllers other than the transport vehicle controller 8 may be provided as the control unit. In the above embodiment and modified example, a shelf unit T is provided as the placement unit, but the placement unit is not particularly limited, and may be, for example, a load port.

[0088] In the first embodiment, the upper storage shelf 40 and the lower storage shelf 50 may be stacked vertically. In this case, the ceiling transport vehicle 1 traveling on the first track 21 can transfer items only to the upper storage shelf 40, and the image captured by the camera 9 when transferring items to the upper storage shelf 40 includes part of the lower storage shelf 50 and part of the item 30 placed on the lower storage shelf 50. However, the determination unit 10 can determine without difficulty whether or not there is a pre-entered item on the upper storage shelf 40 based on the learning model M.

[0089] The components in the above embodiments and modifications are not limited to the materials and shapes described above, and various materials and shapes can be applied. The components in the above embodiments or modifications can be applied as desired to the components in other embodiments or modifications. Some of the components in the above embodiments or modifications can be omitted as appropriate without departing from the spirit of one aspect of the present invention. [Explanation of symbols]

[0090] 1...ceiling transport vehicle, 8...transport vehicle controller (control unit), 9,309,609...camera (imaging unit), 10...judgment unit, 20...track, 21...first track (track), 22...second track (track), 30...item, 41...left shelf section (first placement section), 42...right shelf section (first placement section), 43...lower shelf section (second placement section), 51...left shelf section (third placement section), 52...right shelf section (third placement section), 53...lower shelf section, 100,200,300,400,500,600...ceiling transport vehicle system, 501...first camera (imaging unit), 502...second camera (imaging unit), M...learning model, R...imaging range, T...shelf section (placement section).

Claims

1. An overhead transport vehicle that travels along a track and transports items, a control unit that controls the operation of the ceiling transport vehicle; an imaging unit that captures a plurality of placement units within an imaging range; A ceiling transport vehicle comprising: a determination unit that, when transferring the item between the loading section and the loading section, determines whether or not the item has already been placed on the loading section to be transferred based on the imaging results of the imaging unit.

2. The control unit notifies the determination unit of the placement unit to which the object is to be transferred when transferring the object between the placement unit and the object; The ceiling transport vehicle according to claim 1 , wherein the determining unit determines whether the article is present or absent on the placement unit of the transfer target notified by the control unit based on the imaging result of the imaging unit.

3. The ceiling transport vehicle according to claim 1, wherein the determination unit determines whether or not there are any pre-arranged items, which are the items already placed on the loading section at the loading section, based on the imaging results of the imaging unit when the item is unloaded on the loading section.

4. The determination unit A learning model is stored that outputs output data regarding the presence or absence of the item already placed on the placement section of the transfer target when an image captured by the imaging section and including a range corresponding to the placement section of the transfer target is input as input data, The ceiling transport vehicle according to claim 1 or 2, wherein the presence or absence of an article already placed on the placement section to be transferred is determined based on the imaging result of the imaging section and the learning model.

5. An overhead transport vehicle that transports a plurality of types of articles having different appearances, The ceiling transport vehicle according to claim 4 , wherein the learning model outputs output data regarding whether or not the plurality of types of articles have already been placed on the placement section to be transferred.

6. the determination unit is included in the imaging unit, The control unit obtains only the determination result of whether or not the item has already been placed on the placement section to be transferred from the determination unit included in the imaging unit, and controls the operation of the ceiling transport vehicle based on the determination result.

7. The ceiling transport vehicle according to claim 1; and a plurality of placement sections arranged around the periphery of the track.

8. The plurality of placement units include: a first placement portion disposed at least on one side or the other side of the track in a horizontal direction intersecting with an extension direction of the track; a second placement portion disposed directly below the track, The ceiling transport vehicle system according to claim 7, wherein the imaging unit includes the first placement unit and the second placement unit within an imaging range when transferring the item between the first placement unit and the second placement unit.

9. The plurality of placement units include: a third placement portion disposed at least on one side or the other side of the track in a horizontal direction intersecting the extending direction of the track, the third placement portion being below the first placement portion and spaced apart in the extending direction of the track; The ceiling transport vehicle system according to claim 8 , wherein the imaging unit includes the third placement unit within an imaging range when transferring the article between the ceiling transport vehicle system and the third placement unit.

10. The orbit includes a first orbit and a second orbit disposed directly below the first orbit, The ceiling transport vehicle system according to claim 9 , wherein the ceiling transport vehicle traveling on the first track and the second track transfers the article between the ceiling transport vehicle and the third placement unit.

Images