Article transport apparatus

Abstract

The present application provides an article conveying device (10) comprising a first conveying vehicle (11) for conveying a material box (90), and a first linear path (15) for the first conveying vehicle (11) to travel back and forth. The article conveying device (10) comprises at least a second linear path (16) extending from a specified position of the first linear path (15), and a second conveying vehicle (12) for traveling back and forth on the second linear path and for transferring the material box (90) between the first conveying vehicle at the specified position of the first linear path (15). The first conveying vehicle (11) comprises a first position discrimination device (30) and a second position discrimination device (33) for discriminating the position of the first conveying vehicle on the first linear path. The first conveying vehicle discriminates the position of the first conveying vehicle on the first linear path by switching the first position discrimination device and the second position discrimination device on the first linear path.

Description

Technical Field

[0001] This invention relates to a material handling device that transports materials by exchanging materials between multiple transport vehicles that move back and forth along a straight path. Background Technology

[0002] Previously, such a goods transport device was disclosed in Patent Document 1. The goods transport device in Patent Document 1 is configured such that two parallel travel rails are arranged in an L-shape on the inner and outer sides, and two transport vehicles reciprocate along the travel rails. The two transport vehicles transport goods between two receiving platforms: receiving platforms (placement sections) located near both ends of the L-shaped travel rails, and receiving platforms (placement sections) located near the corners of the L-shaped travel rails. In conventional goods transport devices like the goods transport device in Patent Document 1, the position of the transport vehicle along the travel rails is determined based on the distance measured using an optical distance measuring instrument installed on each transport vehicle.

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: Japanese Patent Application Publication No. 2009-202806 Summary of the Invention

[0006] However, in conventional goods handling equipment, in cases where reflectors for reflecting measuring light emitted from an optical distance measuring instrument are positioned at the corners of the transport vehicle's travel path (e.g., having: in Figure 10 In the case of conventional goods transport equipment 100 (where the first transport vehicle 102, second transport vehicle 103, and third transport vehicle 104 reciprocate along the straight paths 101A, 101B, and 101C of the zigzag travel path 101 as shown), sometimes the second transport vehicle 103, stopped at the corner 107 of the travel path 101, obstructs the optical axis X of the measuring light emitted from the optical distance measuring instrument 105 mounted on the first transport vehicle 102 toward the reflector 106. Therefore, distance measurements based on the distance measuring instrument 105 cannot be adequately performed. Consequently, the position of the first transport vehicle 102 on the travel path 101 (straight path 101A) becomes inaccurate.

[0007] This invention was made to solve the above-mentioned problems, and its purpose is to provide a material handling device that can accurately determine the position of a transport vehicle on a travel path.

[0008] To address the aforementioned issues, the article conveying device of the present invention includes: a first conveying vehicle for conveying articles, and a first straight path for the first conveying vehicle to reciprocate. The article conveying device at least includes: a second straight path extending from a predetermined position of the first straight path, and a second conveying vehicle capable of reciprocating on the second straight path and transferring articles between the second and the first conveying vehicle at the predetermined position of the first straight path. The first conveying vehicle includes: a first position determination device and a second position determination device for determining the position of the first conveying vehicle on the first straight path, and switches between position determination based on the first position determination device and position determination based on the second position determination device on the first straight path.

[0009] Based on the above configuration, the first transport vehicle determines its position on the first straight path by switching between the first position determination device and the second position determination device. Here, the "defined position" on the first straight path refers to any position on the first straight path, and specifically refers to a position within a defined range on the first straight path.

[0010] The first position determination device and the second position determination device of the article conveying equipment of the present invention are composed of an identifier for determining the position of the first conveying vehicle on the first straight path, which is arranged along the first straight path, and a reading device for reading the identifier.

[0011] Based on the above configuration, the first transport vehicle determines its position on the first straight path by reading the identifier through the reading device.

[0012] The first position determination device and the second position determination device of the article conveying equipment of the present invention are composed of optical devices.

[0013] Based on the above configuration, the first transport vehicle uses an optical device to determine its position on the first straight path.

[0014] In the article conveying device of the present invention, when the first conveying vehicle switches between the first position discrimination device and the second position discrimination device, the position of the first conveying vehicle on the first straight path is determined by correcting the difference between the detection value of the first position discrimination device and the detection value of the second position discrimination device.

[0015] Based on the above configuration, when switching between the first position discrimination device and the second position discrimination device, the difference between the detection value of the first position discrimination device and the detection value of the second position discrimination device is corrected.

[0016] According to the article conveying device of the present invention, the position of the first conveyor on the first straight path is determined by switching between the first position determination device and the second position determination device. Therefore, the position of the first conveyor can be determined based on the status of other conveyors (the second conveyor). Thus, other conveyors (the second conveyor) will not obstruct the determination of the position of the first conveyor. Therefore, the position of the first conveyor on the first straight path (travel path) can be accurately determined. Attached Figure Description

[0017] Figure 1 This is a top view showing the article conveying device according to the first embodiment of the present invention.

[0018] Figure 2 This is the front view of the transport vehicle representing the equipment used to transport the aforementioned items.

[0019] Figure 3 This is a top view showing the article conveying device according to the second embodiment of the present invention.

[0020] Figure 4 This is a top view showing the article conveying device according to the third embodiment of the present invention.

[0021] Figure 5 This is a top view showing the article conveying device according to the fourth embodiment of the present invention.

[0022] Figure 6 This is a top view showing the article conveying device according to the fifth embodiment of the present invention.

[0023] Figure 7 This is a top view showing the article conveying device according to the sixth embodiment of the present invention.

[0024] Figure 8 This is a top view showing the article conveying device according to the seventh embodiment of the present invention.

[0025] Figure 9 This is a top view of the article conveying device according to the eighth embodiment of the present invention.

[0026] Figure 10 This is a top view of what was previously a material handling equipment.

[0027] Explanation of reference numerals in the attached figures

[0028] 10. Goods transport equipment; 11. First transport vehicle

[0029] 12 Second transport vehicle 15 First straight path

[0030] 16 Second straight path 30 First position discrimination device

[0031] 33 Second position discrimination device 90 Material box (item) Detailed Implementation

[0032] [First Implementation]

[0033] First, the first embodiment of the article conveying device according to the present invention will be described.

[0034] The article conveying device 10 of the first embodiment is, for example, a device installed between multiple storage sheds in a liquid crystal panel manufacturing plant, wherein the storage sheds store material boxes 90 (an example of "articles") containing liquid crystal panels. In the article conveying device 10 of the first embodiment, the material boxes 90 are conveyed from one storage shed to another.

[0035] like Figure 1 As shown, the goods transport equipment 10, when viewed from above, has a roughly Z-shaped travel path 14 arranged between storage sheds (not shown). This travel path 14 is used for the transport vehicles (first transport vehicle 11, second transport vehicle 12, and third transport vehicle 13) transporting the material boxes 90. The travel path 14 includes three straight paths and two corners. Specifically, the travel path 14 is composed of a first straight path 15, a second straight path 16, a third straight path 17, a first corner 18, and a second corner 19. The first straight path 15 is formed in the center of the travel path 14. The second straight path 16 extends from one end of the first straight path 15 (an example of "a predetermined position of the first straight path"). The third straight path 17 extends from the other end of the first straight path 15 (an example of "a position away from the predetermined position of the first straight path"). The first corner 18 is located at one end of the first straight path 15. The second corner 19 is located at the other end of the first straight path 15.

[0036] The first straight path 15 is a straight travel path for the first transport vehicle 11 to reciprocate. The second straight path 16 is a straight travel path for the second transport vehicle 12 to reciprocate. The second straight path 16 extends perpendicularly to the first straight path 15 from one end of the first straight path 15, horizontally orthogonal to the travel direction of the second transport vehicle 12. The third straight path 17 is a straight travel path for the third transport vehicle 13 to reciprocate. The third straight path 17 extends perpendicularly to the first straight path 15 from the other end of the first straight path 15, horizontally orthogonal to the travel direction of the third transport vehicle 13. Here, the third straight path 17 extends on the side of the first straight path 15 opposite to the side where the second straight path 16 extends. The second straight path 16 and the third straight path 17 are extended from the first straight path 15 in opposite directions.

[0037] The first corner portion 18 is formed at one end of the first straight path 15 and is formed at the confluence of the first straight path 15 and the second straight path 16. The second corner portion 19 is formed at the other end of the first straight path 15 and is formed at the confluence of the first straight path 15 and the third straight path 17.

[0038] Near the first corner 18, there is a first receiving platform 20 for receiving the material box 90. The first receiving platform 20 holds the material box 90 transported by the first transport vehicle 11 (unloading), and the held material box 90 is transferred to the second transport vehicle 12 (loading). Additionally, the first receiving platform 20 holds the material box 90 transported by the second transport vehicle 12, and the held material box 90 is transferred to the first transport vehicle 11.

[0039] A second receiving platform 21 for receiving material boxes 90 is provided near the second corner 19. Material boxes 90 transported by the first transport vehicle 11 are placed on the second receiving platform 21, and the placed material boxes 90 are transferred to the third transport vehicle 13. Additionally, material boxes 90 transported by the third transport vehicle 13 are placed on the second receiving platform 21, and the placed material boxes 90 are transferred to the first transport vehicle 11.

[0040] Near the end of the second straight path 16, and near the end on the opposite side of the first corner 18, a third receiving platform 22 for receiving the material box 90 is provided. The material box 90 transported by the second transport vehicle 12, or the material box 90 transported by the storage shed (not shown) is transferred to the second transport vehicle 12.

[0041] Near the end of the third straight path 17, and near the end on the opposite side of the second corner 19, a fourth receiving platform 23 for receiving the material box 90 is provided. The fourth receiving platform 23 holds the material box 90 transported by the third transport vehicle 13, or the material box 90 transported from the storage shed (not shown) is transferred to the third transport vehicle 13.

[0042] like Figure 2 As shown, the first transport vehicle 11, the second transport vehicle 12, and the third transport vehicle 13 are all of the same structure, consisting of a vehicle body 25 with front and rear wheels 24, and a lift 26 mounted on the vehicle body 25 to support the material box 90 for lifting. The first to third transport vehicles 11, 12, and 13 travel along the travel rails 27 laid on the straight paths (straight paths 15, 16, and 17). The first to third transport vehicles 11, 12, and 13 lift and lower the lift 26 to unload and load the material box 90 at their respective receiving platforms (receiving platforms 20, 21, 22, and 23).

[0043] like Figure 1 As shown, the first to third transport vehicles 11, 12, and 13 determine their positions on each straight path of their reciprocating journey using a position determination device (barcode positioning system) consisting of barcode strips and barcode readers. The movement of the first to third transport vehicles 11, 12, and 13 is controlled based on their positions on each straight path determined by this position determination device.

[0044] The first transport vehicle 11 determines its position on the first straight path 15 using two position determination devices: the first position determination device 30 and the second position determination device 33.

[0045] The first position determination device 30 determines the position of the first transport vehicle 11 on the first straight path 15 when the first transport vehicle 11 travels from the second corner 19 (the other end of the first straight path 15) towards the first corner 18 (one end of the first straight path 15). The first position determination device 30 consists of a first barcode tape 31 (an example of an "identifier") and a first barcode reader 32 (an example of a "reading device"). The first barcode tape 31 records information of the absolute position (distance) between the second corner 19 and a predetermined position 28 on the first straight path 15 in barcode format. The first barcode reader 32 optically reads the barcode recorded on the first barcode tape 31.

[0046] The first barcode strip 31 extends along the first straight path 15 from the second corner 19 to a predetermined position 28 on the first straight path 15, and is disposed on one side of the first straight path 15. A first barcode reader 32 is disposed on one side of the first transport vehicle 11 at a position where the barcode of the first barcode strip 31 can be read. Specifically, the first barcode reader 32 is disposed on the side of the first transport vehicle 11, which is on the left side of the first transport vehicle 11 in the direction of travel when the first transport vehicle 11 travels towards the first corner 18.

[0047] The second position determination device 33 determines the position of the first transport vehicle 11 on the first straight path 15 when the first transport vehicle 11 travels from the first corner 18 toward the second corner 19. The second position determination device 33 consists of a second barcode tape 34 (an example of an "identifier") and a second barcode reader 35 (an example of a "reading device"). The second barcode tape 34 records information of the absolute position (distance) between the first corner 18 and a predetermined position 28 on the first straight path 15 in barcode format. The second barcode reader 35 optically reads the barcode recorded on the second barcode tape 34.

[0048] The second barcode strip 34 extends along the first straight path 15 from the first corner 18 to a predetermined position 28 on the first straight path 15, on the other side of the first straight path 15 (the side opposite to the side where the first barcode strip 31 is located). On the other side of the first transport vehicle 11 (the side opposite to the side where the first barcode reader 32 is located), a second barcode reader 35 is provided at a position where the barcode of the second barcode strip 34 can be read. Specifically, the second barcode reader 35 is located on the side of the first transport vehicle 11 that is to the left of the direction of travel of the first transport vehicle 11 when the first transport vehicle 11 is traveling towards the second corner 19.

[0049] The second transport vehicle 12 determines its position on the second straight path 16 by using a third position determination device 36.

[0050] The third position determination device 36 consists of a third barcode strip 37 and a third barcode reader 38. The third barcode strip 37 records information on the absolute position (distance) between the first corner 18 and the end of the second straight path 16 in barcode form. The third barcode reader 38 optically reads the barcode recorded on the third barcode strip 37.

[0051] The third barcode strip 37 extends along the second straight path 16 from the first corner 18 to the end of the second straight path 16, and is disposed on one side of the second straight path 16. A third barcode reader 38 is disposed on one side of the second transport vehicle 12 at a position where the barcode of the third barcode strip 37 can be read. Specifically, the third barcode reader 38 is disposed on the side of the second transport vehicle 12, which is on the left side of the second transport vehicle 12 in the direction of travel when the second transport vehicle 12 is traveling towards the first corner 18.

[0052] The third transport vehicle 13 determines its position on the third straight path 17 by using a fourth position determination device 39.

[0053] The fourth position determination device 39 consists of a fourth barcode tape 40 and a fourth barcode reader 41. The fourth barcode tape 40 records information on the absolute position (distance) between the second corner 19 and the end of the third straight path 17 in barcode form. The fourth barcode reader 41 optically reads the barcode recorded on the fourth barcode tape 40.

[0054] The fourth barcode strip 40 extends along the third straight path 17 from the second corner 19 to the end of the third straight path 17, and is disposed on one side of the third straight path 17. A fourth barcode reader 41 is disposed on one side of the third transport vehicle 13 at a position where the barcode of the fourth barcode strip 40 can be read. Specifically, the fourth barcode reader 41 is disposed on the side of the third transport vehicle 13, which is on the left side of the third transport vehicle 13 in the direction of travel when the third transport vehicle 13 travels towards the second corner 19.

[0055] The first to third transport vehicles 11, 12 and 13 are controlled to drive and perform other actions by controllers located on the ground side and vehicle body side controllers located on the sides of the transport vehicles.

[0056] The signal transmission and reception between the ground-side controller and the vehicle-side controller of the first transport vehicle 11 is carried out by optical transmission via transceiver units 42 and 45. The transceiver unit 42 of the ground-side controller is located at the first corner 18.

[0057] The ground-side controller controls the movement of the first transport vehicle 11 based on the position (distance) of the first transport vehicle 11 on the first straight path 15 determined by the first position determination device 30 or the second position determination device 33. Specifically, the ground-side controller uses the position of the first transport vehicle 11 determined based on the detection signal of the first barcode reader 32 or the second barcode reader 35 as at least one condition to send a transport command to the vehicle-side controller of the first transport vehicle 11.

[0058] The vehicle-side controller installed on the first transport vehicle 11 controls the movement of the first transport vehicle 11 based on the transport commands from the ground-side controller.

[0059] The ground-side controller and the vehicle-side controller of the second transport vehicle 12 are transmitted and received using optical transmission via transceiver units 43 and 46. The transceiver unit 43 of the ground-side controller is located at the end of the second straight path 16. The ground-side controller sends a transport command to the vehicle-side controller of the second transport vehicle 12, taking at least the position of the second transport vehicle 12 determined based on the detection signal of the third barcode reader 38 as one condition.

[0060] The ground-side controller and the vehicle-side controller of the third transport vehicle 13 are connected by optical transmission via transceiver units 44 and 47. The transceiver unit 44 of the ground-side controller is located at the end of the third straight path 17.

[0061] The ground-side controller uses the position of the third transport vehicle 13, determined based on the detection signal of the fourth barcode reader 41, as a condition to send a transport command to the vehicle-side controller of the third transport vehicle 13.

[0062] Next, the position determination of the first transport vehicle 11 on the first straight path 15 by the first position determination device 30 and the second position determination device 33 will be explained.

[0063] like Figure 1 As shown, when the first transport vehicle 11 travels from the second corner 19 towards the first corner 18, the position of the first transport vehicle 11 on the first straight path 15 is first determined by the first position determination device 30. Specifically, the first barcode reader 32 reads the barcode on the first barcode tape 31 in conjunction with the travel of the first transport vehicle 11 and sends the read information to the vehicle-side controller. The vehicle-side controller determines the position of the first transport vehicle 11 on the first straight path 15 based on the information sent from the first barcode reader 32 (the detection value of the first position determination device 30) and sends the position of the first transport vehicle 11 to the ground-side controller. The first barcode reader 32 reads the barcode on the first barcode tape 31 in conjunction with the travel of the first transport vehicle 11 until it reaches the designated position 28 on the first straight path 15 where the first barcode tape 31 is located. Here, the so-called designated position 28 of the first straight path 15 refers to any position on the first straight path 15, and specifically to the position within a designated range on the first straight path 15. For example, the designated position 28 of the first straight path 15 is the position within a designated range at the center of the first straight path 15.

[0064] On the other hand, when the first transport vehicle 11 travels to the designated position 28 of the first straight path 15, the second barcode reader 35, in coordination with the movement of the first transport vehicle 11, begins to read the barcode on the second barcode strip 34 and sends the read information to the vehicle-side controller. That is, when the first transport vehicle 11 travels to the designated position 28 of the first straight path 15, the first barcode reader 32 reads the barcode on the first barcode strip 31, and the second barcode reader 35 reads the barcode on the second barcode strip 34.

[0065] When the first transport vehicle 11 is traveling at a designated position 28 on the first straight path 15, the vehicle-side controller determines the position of the first transport vehicle 11 on the first straight path 15 based on information sent from the first barcode reader 32 and the second barcode reader 35 (detection values ​​from the first and second position determination devices 30 and 33). At this time, the vehicle-side controller corrects the difference between the detection value of the first position determination device 30 and the detection value of the second position determination device 33 to determine the position of the first transport vehicle 11 on the first straight path 15.

[0066] When the first transport vehicle 11 passes the designated position 28 of the first straight path 15, the reading performed by the first barcode reader 32 ends, and only the second barcode reader 35 reads the barcode of the second barcode tape 34 in conjunction with the movement of the first transport vehicle 11. That is, at the moment when the first transport vehicle 11 passes the designated position 28 of the first straight path 15, the position determination device switches from the first position determination device 30 to the second position determination device 33. Moreover, the vehicle-side controller determines the position of the first transport vehicle 11 on the first straight path 15 based on the information sent from the second barcode reader 35 (the detection value of the second position determination device 33).

[0067] Similarly, when the first transport vehicle 11 moves from the first corner 18 towards the second corner 19, firstly, the second barcode reader 35 reads the barcode on the second barcode strip 34 in conjunction with the movement of the first transport vehicle 11, and sends the read information to the vehicle-side controller. Furthermore, when the first transport vehicle 11 reaches the designated position 28 on the first straight path 15, the second barcode reader 35 reads the barcode on the second barcode strip 34, and the first barcode reader 32 begins reading the barcode on the first barcode strip 31 in conjunction with the movement of the first transport vehicle 11, and sends the read information to the vehicle-side controller. At this time, the vehicle-side controller corrects the difference between the detection value of the first position determination device 30 and the detection value of the second position determination device 33 to determine the position of the first transport vehicle 11 on the first straight path 15.

[0068] When the first transport vehicle 11 passes the designated position 28 of the first straight path 15, the reading performed by the second barcode reader 35 ends, and only the first barcode reader 32 reads the barcode of the first barcode tape 31 in conjunction with the movement of the first transport vehicle 11. That is, at the moment when the first transport vehicle 11 passes the designated position 28 of the first straight path 15, the position determination device switches from the second position determination device 33 to the first position determination device 30.

[0069] Thus, in the first embodiment of the article conveying device 10, when the first conveyor 11 travels from the second corner 19 to the first corner 18, at the moment when the first conveyor 11 passes the predetermined position 28 of the first straight path 15, the position determination device switches from the first position determination device 30 to the second position determination device 33. Furthermore, when the first conveyor 11 travels from the first corner 18 to the second corner 19, at the moment when the first conveyor 11 passes the predetermined position 28 of the first straight path 15, the position determination device switches from the second position determination device 33 to the first position determination device 30. That is, in the first embodiment of the article conveying device 10, on the first straight path 15, the first position determination device 30 and the second position determination device 33 are switched according to the travel position of the first conveyor 11, thereby enabling continuous and accurate determination of the position of the first conveyor 11 on the first straight path 15.

[0070] In the article conveying equipment 10 of the first embodiment, the position of the first conveyor 11 on the first straight path 15 is determined by the first and second position determination devices 30 and 33 (barcode positioning system) consisting of the first and second barcode tapes 31 and 34 and the first and second barcode readers 32 and 35. Therefore, when determining the position of the first conveyor 11, even if other conveyors (the second conveyor 12 and the third conveyor 13) stop at corners (the first corner 18 and the second corner 19), the determination by the first and second position determination devices 30 and 33 will not be blocked by other conveyors (the second conveyor 12 and the third conveyor 13).

[0071] [Second Implementation]

[0072] Next, a second embodiment of the article conveying device according to the present invention will be described. Furthermore, in the article conveying device 10A of the second embodiment, descriptions of configurations identical to those of the article conveying device 10 of the first embodiment will be omitted.

[0073] like Figure 3As shown, in the second embodiment of the goods transport equipment 10A, the first transport vehicle 11, which reciprocates on the first straight path 15, is similar to the goods transport equipment 10 of the first embodiment in that its position on the first straight path 15 is determined by a first position determination device 30 and a second position determination device 33, which are composed of a barcode strip and a barcode reader. Similarly, the second transport vehicle 12, which reciprocates on the second straight path 16, is determined by a third position determination device 36A, which is composed of an optical distance measuring instrument. Likewise, the third transport vehicle 13, which reciprocates on the third straight path 17, is determined by a fourth position determination device 39A, which is composed of an optical distance measuring instrument.

[0074] The third position determination device 36A consists of an optical first distance measuring instrument 48 installed on the second transport vehicle 12 and a first reflector 49 installed at the end of the second straight path 16 (the end opposite to the first corner 18). The first distance measuring instrument 48 is installed in front of the second transport vehicle 12 in the direction of travel when the second transport vehicle 12 is traveling toward the end of the second straight path 16.

[0075] The fourth position determination device 39A consists of an optical second distance measuring instrument 50 installed on the third transport vehicle 13 and a second reflector 51 installed at the end of the third straight path 17 (the end opposite to the second corner 19). The second distance measuring instrument 50 is installed in front of the third transport vehicle 13 in the direction of travel when the third transport vehicle 13 is traveling toward the end of the third straight path 17.

[0076] In the second embodiment of the article conveying device 10A, since it is similar to the first embodiment of the article conveying device 10, the first and second position determination devices 30 and 33 (barcode positioning system) are used. Therefore, when determining the position of the first conveyor 11, the determination of the first and second position determination devices 30 and 33 will not be blocked by other conveyor vehicles (the second conveyor 12 and the third conveyor 13) other than the first conveyor 11.

[0077] [Third Implementation]

[0078] Next, a third embodiment of the article conveying device according to the present invention will be described. Furthermore, in the article conveying device 10B of the third embodiment, descriptions of configurations identical to those of the article conveying devices 10 and 10A of the first and second embodiments will be omitted.

[0079] like Figure 4As shown, in the article conveying device 10B of the third embodiment, the first conveyor 11 determines its position on the first straight path 15 using a first position determination device 30A (an example of an "optical device") and a second position determination device 33A (an example of an "optical device"), both of which are composed of an optical distance measuring instrument. That is, in the article conveying device 10B of the third embodiment, the position of the first conveyor 11 on the first straight path 15 is determined by two optical position determination devices.

[0080] In addition, the second transport vehicle 12 and the third transport vehicle 13, like the article transport equipment 10A of the second embodiment, determine their positions on the second straight path 16 or the third straight path 17 by a third position determination device 36A or a fourth position determination device 39A composed of an optical distance measuring instrument.

[0081] The first position determination device 30A consists of an optical third distance measuring instrument 52 installed on the first transport vehicle 11 and a third reflector 53 installed on the first corner 18. The third distance measuring instrument 52 is installed in front of the first transport vehicle 11 in the direction of travel when the first transport vehicle 11 is traveling toward the first corner 18.

[0082] The second position determination device 33A consists of an optical fourth distance measuring instrument 54 installed on the first transport vehicle 11 and a fourth reflector 55 installed at the second corner 19. The fourth distance measuring instrument 54 is installed in front of the first transport vehicle 11 in the direction of travel when the first transport vehicle 11 is traveling toward the second corner 19. That is, the fourth distance measuring instrument 54 is installed on the side of the first transport vehicle 11 opposite to the third distance measuring instrument 52.

[0083] The ground-side controller controls the movement of the first transport vehicle 11 based on the position of the first transport vehicle 11 on the first straight path 15 detected by the third distance measuring instrument 52 or the fourth distance measuring instrument 54. The ground-side controller and the vehicle-side controller receive and transmit signals via optical transmission through transceiver units 42 and 45.

[0084] Next, the position determination of the first transport vehicle 11 on the first straight path 15 by the first position determination device 30A and the second position determination device 33A will be explained.

[0085] like Figure 4As shown, when the first transport vehicle 11 travels from the second corner 19 towards the first corner 18, the position of the first transport vehicle 11 on the first straight path 15 is determined by the first position determination device 30A. Specifically, the third distance measuring instrument 52 measures the distance between the first transport vehicle 11 and the third reflector 53 in conjunction with the travel of the first transport vehicle 11. The third distance measuring instrument 52 sends the measured value to the vehicle-side controller. The vehicle-side controller determines the position of the first transport vehicle 11 on the first straight path 15 based on the measured distance value sent from the third distance measuring instrument 52. The third distance measuring instrument 52 measures the distance between the first transport vehicle 11 and the third reflector 53 until the first transport vehicle 11 reaches the first corner 18.

[0086] On the other hand, when the first transport vehicle 11 travels from the first corner 18 towards the second corner 19, the position of the first transport vehicle 11 on the first straight path 15 is determined by the second position determination device 33A. That is, when the first transport vehicle 11 travels from the first corner 18 towards the second corner 19, the position determination device is switched from the first position determination device 30A to the second position determination device 33A to determine the position of the first transport vehicle 11 on the first straight path 15. Specifically, the fourth distance measuring instrument 54 measures the distance between the first transport vehicle 11 and the fourth reflector 55 in conjunction with the travel of the first transport vehicle 11. The fourth distance measuring instrument 54 sends the measured value to the first controller 42. The first controller 42 determines the position of the first transport vehicle 11 on the first straight path 15 based on the measured distance value sent from the fourth distance measuring instrument 54. The fourth distance measuring instrument 54 measures the distance between the first transport vehicle 11 and the fourth reflector 55 until the first transport vehicle 11 reaches the second corner 19.

[0087] Thus, in the article conveying device 10B of the third embodiment, the first position determination device 30A and the second position determination device 33A are switched according to the travel direction of the first conveyor 11 on the first straight path 15, thereby determining the position of the first conveyor 11 on the first straight path 15. That is, at the moment when the travel direction of the first conveyor 11 on the first straight path 15 changes (when the first conveyor 11 stops at the first corner 18 or the second corner 19), the position of the first conveyor 11 on the first straight path 15 is determined by switching the first position determination device 30A and the second position determination device 33A.

[0088] Furthermore, when the first transport vehicle 11 is traveling from the second corner 19 towards the first corner 18, and the second transport vehicle 12 stops or enters the first corner 18, the position determination device is switched from the first position determination device 30A to the second position determination device 33A to determine the position of the first transport vehicle 11 on the first straight path 15 when the second transport vehicle 12 is detected. Similarly, when the first transport vehicle 11 is traveling from the first corner 18 towards the second corner 19, and the third transport vehicle 13 stops or enters the second corner 19, the position determination device is switched from the second position determination device 33A to the first position determination device 30A to determine the position of the first transport vehicle 11 on the first straight path 15 when the third transport vehicle 13 is detected. That is, the position determination device of the optical axis of the measuring light illuminating the distance measuring instrument is not blocked by other transport vehicles (the second transport vehicle 12 and the third transport vehicle 13) other than the first transport vehicle 11, so that the position of the first transport vehicle 11 can be determined.

[0089] [Fourth Implementation]

[0090] Next, a fourth embodiment of the article conveying device according to the present invention will be described. Furthermore, in the article conveying device 10C of the fourth embodiment, descriptions of configurations identical to those of the article conveying devices 10, 10A, and 10B of the first to third embodiments will be omitted.

[0091] like Figure 5 As shown, in the fourth embodiment of the article conveying device 10C, similarly to the third embodiment of the article conveying device 10B, the first conveying vehicle 11 determines its position on the first straight path 15 using a first position determination device 30A and a second position determination device 33A, both composed of an optical distance measuring instrument. Furthermore, similarly to the first embodiment of the article conveying device 10, the second conveying vehicle 12 and the third conveying vehicle 13 determine their positions on the second straight path 16 or the third straight path 17 using a third position determination device 36 or a fourth position determination device 39, both composed of a barcode strip and a barcode reader.

[0092] Similar to the article transport device 10B of the third embodiment, at the moment when the travel direction of the first transport vehicle 11 on the first straight path 15 changes (when the first transport vehicle 11 stops at the first corner 18 or the second corner 19), or when other transport vehicles (the second transport vehicle 12 and the third transport vehicle 13) are detected, the position of the first transport vehicle 11 on the first straight path 15 is determined by switching between the first position determination device 30A and the second position determination device 33A.

[0093] [Fifth Implementation]

[0094] Next, a fifth embodiment of the article conveying device according to the present invention will be described. Furthermore, in the article conveying device 10D of the fifth embodiment, descriptions of configurations identical to those of the article conveying devices 10, 10A, 10B, and 10C of the first to fourth embodiments will be omitted.

[0095] In the article transport equipment 10D of the fifth embodiment, the travel path for each transport vehicle (first transport vehicle 11, second transport vehicle 12, and third transport vehicle 13) is constituted by a roughly C-shaped travel path 14A when viewed from above. The travel path 14A is configured such that the extension direction of the second straight path 16A, which extends from one end of the first straight path 15 (an example of "the predetermined position of the first straight path"), and the extension direction of the third straight path 17A, which extends from the other end of the first straight path 15 (an example of "the position away from the predetermined position of the first straight path"), are in the same direction.

[0096] Similar to the article transport device 10B of the third embodiment, the first transport vehicle 11 determines its position on the first straight path 15 using a first position determination device 30A and a second position determination device 33A, both composed of optical distance measuring instruments. Similarly to the article transport device 10A of the second embodiment, the second transport vehicle 12 and the third transport vehicle 13 determine their positions on the second straight path 16A or the third straight path 17A using a third position determination device 36A or a fourth position determination device 39A, both composed of optical distance measuring instruments.

[0097] Similar to the article transport device 10B of the third embodiment, at the moment when the travel direction of the first transport vehicle 11 on the first straight path 15 changes (when the first transport vehicle 11 stops at the first corner 18 or the second corner 19), or when other transport vehicles (the second transport vehicle 12 and the third transport vehicle 13) are detected, the position of the first transport vehicle 11 on the first straight path 15 is determined by switching between the first position determination device 30A and the second position determination device 33A.

[0098] [Sixth Implementation]

[0099] Next, the sixth embodiment of the article conveying device according to the present invention will be described. In addition, in the article conveying device 10E of the sixth embodiment, the description of the same configuration as that of the article conveying devices 10, 10A, 10B, 10C and 10D of the first to fifth embodiments will be omitted.

[0100] like Figure 7 As shown, in the sixth embodiment of the article transport device 10E, similarly to the fifth embodiment of the article transport device 10D, the travel path for each transport vehicle (first transport vehicle 11, second transport vehicle 12, and third transport vehicle 13) to travel is constituted by a travel path 14A that is approximately C-shaped when viewed from above.

[0101] Similar to the article transport device 10B of the third embodiment, the first transport vehicle 11 determines its position on the first straight path 15 using a first position determination device 30A and a second position determination device 33A, both composed of an optical distance measuring instrument. Similarly, similar to the article transport device 10 of the first embodiment, the second transport vehicle 12 and the third transport vehicle 13 determine their positions on the second straight path 16A or the third straight path 17A using a third position determination device 36 or a fourth position determination device 39, both composed of a barcode strip and a barcode reader.

[0102] Similar to the article transport device 10B of the third embodiment, at the moment when the travel direction of the first transport vehicle 11 on the first straight path 15 changes (when the first transport vehicle 11 stops at the first corner 18 or the second corner 19), or when other transport vehicles (the second transport vehicle 12 and the third transport vehicle 13) are detected, the position of the first transport vehicle 11 on the first straight path 15 is determined by switching between the first position determination device 30A and the second position determination device 33A.

[0103] [Seventh Implementation]

[0104] Next, the seventh embodiment of the article conveying device according to the present invention will be described. In addition, in the article conveying device 10F of the seventh embodiment, the description of the same configuration as that of the article conveying devices 10, 10A, 10B, 10C, 10D and 10E of the first to sixth embodiments will be omitted.

[0105] like Figure 8As shown, in the article transport device 10F of the seventh embodiment, the travel path for each transport vehicle (first transport vehicle 11, second transport vehicle 12, and third transport vehicle 13) is constituted by a travel path 14B that is approximately T-shaped when viewed from above. Specifically, the travel path 14B is composed of the following parts: a first straight path 15 for reciprocating travel of the first transport vehicle 11; a second straight path 16B extending from one end of the first straight path 15 (an example of the "predetermined position of the first straight path") for reciprocating travel of the second transport vehicle 12; a third straight path 17B extending from the other end of the first straight path 15 (an example of the "predetermined position of the first straight path") for reciprocating travel of the third transport vehicle 13; and a first merging section 29 provided at one end of the first straight path 15 for the second straight path 16B and the third straight path 17B to merge.

[0106] A first receiving platform 20A for receiving material boxes 90 is provided at the first confluence section 29. Material boxes 90 transported by the first transport vehicle 11 are placed on the first receiving platform 20A, and the placed material boxes 90 are transferred to the second transport vehicle 12 or the third transport vehicle 13. Additionally, material boxes 90 transported by the second transport vehicle 12 (or the third transport vehicle 13) are placed on the first receiving platform 20A, and the placed material boxes 90 are transferred to the first transport vehicle 11 or the third transport vehicle 13 (or the second transport vehicle 12).

[0107] The first transport vehicle 11 uses two position determination devices (barcode positioning systems), namely the first position determination device 30B and the second position determination device 33B, which consist of a barcode strip and a barcode reader, to determine its position on the first straight path 15.

[0108] The first position determination device 30B determines the position of the first transport vehicle 11 on the first straight path 15 when the first transport vehicle 11 travels from the other end 15A of the first straight path 15 toward the first merging section 29 (one end of the first straight path 15). The first position determination device 30B consists of a first barcode tape 31A (an example of an "identifier"), a second barcode tape 34A (an example of an "identifier"), and a first barcode reader 32A (an example of a "reading device"). The first barcode tape 31A records information in barcode about the absolute position (distance) from the other end 15A of the first straight path 15 to the first merging section 29. The second barcode tape 34A records information in barcode about the absolute position (distance) at the first merging section 29. The first barcode reader 32A optically reads the barcodes recorded on the first barcode strip 31A and the second barcode strip 34A.

[0109] The first barcode tape 31A is extended along the first straight path 15 on one side of the first straight path 15, between the other end 15A of the first straight path 15 and in front of the first merging part 29.

[0110] The second barcode tape 34A extends along the first straight path 15 and is disposed on the first confluence portion 29, and is disposed on one side of the first straight path 15. That is, the second barcode tape 34A is disposed on the side of the first straight path 15 on which the first barcode tape 31A is disposed.

[0111] In the article conveying device 10F of the seventh embodiment, since the travel guide rail 27A for the first conveyor 11 and the travel guide rail 27B for the second conveyor 12 and the third conveyor 13 intersect at the first confluence section 29, the first barcode tape 31A cannot be extended to the first confluence section 29. Therefore, a second barcode tape 34A is provided at the first confluence section 29.

[0112] On one side of the first transport vehicle 11, a first barcode reader 32A is provided at a position where the barcodes of the first barcode tape 31A and the second barcode tape 34A can be read. Specifically, the first barcode reader 32A is provided on the side of the first transport vehicle 11, which is on the right side of the first transport vehicle 11 in the direction of travel when the first transport vehicle 11 is traveling toward the first merging section 29, and is located on the front side in the direction of travel of the first transport vehicle 11.

[0113] The second position determination device 33B determines the position of the first transport vehicle 11 on the first straight path 15 when the first transport vehicle 11 travels from the first merging section 29 toward the other end 15A of the first straight path 15. The second position determination device 33B consists of a first barcode tape 31A (an example of an "identifier"), a second barcode tape 34A (an example of an "identifier"), and a second barcode reader 35A (an example of a "reading device"), wherein the second barcode reader 35A optically reads the barcodes recorded on the first barcode tape 31A and the second barcode tape 34A. That is, the first position determination device 30B and the second position determination device 33B both function as the first barcode tape 31A and the second barcode tape 34A.

[0114] A second barcode reader 35A is provided on one side of the first transport vehicle 11 at a position where the barcodes of the first barcode tape 31A and the second barcode tape 34A can be read. Specifically, the second barcode reader 35A is located on the side of the first transport vehicle 11, which is on the right side of the first transport vehicle 11 in the direction of travel when the first transport vehicle 11 is traveling toward the first merging section 29, and is located on the rear side in the direction of travel of the first transport vehicle 11. That is, the first barcode reader 32A and the second barcode reader 35A are located on the same side of the first transport vehicle 11 and are arranged in a front-to-back arrangement in the direction of travel of the first transport vehicle 11.

[0115] The second transport vehicle 12 determines its position on the second straight path 16B by using a third position determination device 36B, which consists of a barcode tape 80 and barcode readers 38A and 38B.

[0116] The third transport vehicle 13 determines its position on the third straight path 17B by using the fourth position determination device 39B, which consists of a barcode tape 80 and barcode readers 41A and 41B.

[0117] Next, the position determination of the first transport vehicle 11 on the first straight path 15 will be explained by the first position determination device 30B and the second position determination device 33B.

[0118] like Figure 8 As shown, when the first transport vehicle 11 travels from the other end 15A of the first straight path 15 toward the first merging section 29, the position of the first transport vehicle 11 on the first straight path 15 is first determined by the first position determination device 30B. Specifically, the first barcode reader 32A reads the barcode of the first barcode tape 31A in conjunction with the travel of the first transport vehicle 11 and sends the read information to the vehicle-side controller. The vehicle-side controller determines the position of the first transport vehicle 11 on the first straight path 15 based on the information sent from the first barcode reader 32A (the detection value of the first position determination device 30B). The first barcode reader 32A reads the barcode of the first barcode tape 31A in conjunction with the travel of the first transport vehicle 11 until it reaches the first merging section 29 where the first barcode tape 31A is located.

[0119] On the other hand, when the first transport vehicle 11 travels to the first merging section 29, the second barcode reader 35A, in conjunction with the movement of the first transport vehicle 11, begins to read the barcode on the first barcode tape 31A and sends the read information to the vehicle-side controller. That is, when the first transport vehicle 11 is traveling in front of the first merging section 29, the first barcode reader 32A reads the barcode on the first barcode tape 31A, and the second barcode reader 35A also reads the barcode on the first barcode tape 31A.

[0120] When the first transport vehicle 11 is traveling in front of the first merging section 29, the first controller 42 determines the position of the first transport vehicle 11 on the first straight path 15 based on the information sent from the first barcode reader 32A and the second barcode reader 35A (the detection values ​​of the first and second position determination devices 30B and 33B).

[0121] When the first transport vehicle 11 travels at the intersection of travel rails 27A and 27B, the reading performed by the first barcode reader 32A is interrupted, and only the second barcode reader 35A reads the barcode of the first barcode tape 31A in conjunction with the travel of the first transport vehicle 11. That is, when the first transport vehicle 11 travels at the intersection of travel rails 27A and 27B, the position determination device switches from the first position determination device 30B to the second position determination device 33B. Moreover, the vehicle-side controller determines the position of the first transport vehicle 11 on the first straight path 15 based on the information sent from the second barcode reader 35 (the detection value of the second position determination device 33B). Furthermore, when the first transport vehicle 11 passes the intersection of travel rails 27A and 27B, the reading by the first barcode reader 32A resumes. Only the first barcode reader 32A reads the barcode of the second barcode tape 34A in conjunction with the movement of the first transport vehicle 11. That is, at the moment the first transport vehicle 11 passes the intersection of travel rails 27A and 27B, the vehicle-side controller, based on the information sent by the first barcode reader 32A and the information sent by the second barcode reader 35A, corrects the difference between the detection value of the first position determination device 30B and the detection value of the second position determination device 33B to determine the position of the first transport vehicle 11 on the first straight path 15.

[0122] Subsequently, the position determination device switches again from the second position determination device 33B to the first position determination device 30B.

[0123] Similarly, when the first transport vehicle 11 travels from the first merging section 29 toward the other end 15A of the first straight path 15, firstly, the second barcode reader 35A reads the barcode of the second barcode tape 34A in conjunction with the travel of the first transport vehicle 11, and sends the read information to the vehicle-side controller. Furthermore, when the first transport vehicle 11 travels at the intersection of the travel rails 27A and 27B, the reading performed by the second barcode reader 35A is interrupted, and the first barcode reader 32A reads the barcode of the second barcode tape 34A in conjunction with the travel of the first transport vehicle 11. That is, when the first transport vehicle 11 travels at the intersection of the travel rails 27A and 27B, the position determination device switches from the second position determination device 33B to the first position determination device 30B. Furthermore, when the first transport vehicle 11 passes the intersection of the travel rails 27A and 27B, the second barcode reader 35A resumes reading the barcode. Only the second barcode reader 35A reads the barcode of the first barcode tape 31A in conjunction with the movement of the first transport vehicle 11. That is, at the moment the first transport vehicle 11 passes the intersection of the travel rails 27A and 27B, the position determination device switches again from the first position determination device 30B to the second position determination device 33B.

[0124] Thus, in the article conveying device 10F of the seventh embodiment, when the first conveyor 11 travels from the other end 15A of the first straight path 15 to the first confluence section 29, at the moment when the first conveyor 11 travels at the position where the travel guide rail 27A and the travel guide rail 27B intersect, the position determination device switches from the first position determination device 30B to the second position determination device 33B. At the moment when the first conveyor 11 passes the position where the travel guide rail 27A and the travel guide rail 27B intersect, the position determination device switches from the second position determination device 33B to the first position determination device 30B again. Furthermore, when the first transport vehicle 11 travels from the first merging section 29 to the other end 15A of the first straight path 15, at the moment when the first transport vehicle 11 travels at the position where the travel guide rail 27A intersects with the travel guide rail 27B, the position determination device switches from the second position determination device 33B to the first position determination device 30B. At the moment when the first transport vehicle 11 passes the position where the travel guide rail 27A intersects with the travel guide rail 27B, the position determination device switches from the first position determination device 30B to the second position determination device 33B again. That is, in the article transport equipment 10F of the seventh embodiment, the position of the first transport vehicle 11 on the first straight path 15 is determined by switching between the first position determination device 30B and the second position determination device 33B on the first straight path 15.

[0125] Furthermore, in the article transport equipment 10F of the seventh embodiment, although the second transport vehicle 12 travels back and forth on the second straight path 16B and the third transport vehicle 13 travels back and forth on the third straight path 17B, it is not limited to this. It is also possible that only either the second transport vehicle 12 or the third transport vehicle 13 travels back and forth on the second straight path 16B and the third straight path 17B.

[0126] [Eighth Implementation]

[0127] Next, the eighth embodiment of the article conveying device according to the present invention will be described. In addition, in the article conveying device 10G of the eighth embodiment, the description of the same configuration as that of the article conveying devices 10, 10A, 10B, 10C, 10D, 10E and 10F of the first to seventh embodiments will be omitted.

[0128] In the article transport equipment 10G of the eighth embodiment, the travel path for each transport vehicle (first transport vehicle 11, second transport vehicle 12, third transport vehicle 13, and fourth transport vehicle 60) is constituted by a travel path 14C that is approximately cross-shaped when viewed from above. Specifically, the travel path 14C is composed of a first straight path 15, a second straight path 16B, a third straight path 17B, a fourth straight path 61, and a second confluence section 62. The first straight path 15 is the path for the first transport vehicle 11 to travel back and forth. The second straight path 16B is the path that extends at a right angle from one end of the first straight path 15 (an example of the "prescribed position of the first straight path") and is used for the second transport vehicle 12 to travel back and forth. The third straight path 17B extends at a right angle from one end of the first straight path 15 to the other side (an example of the "prescribed position of the first straight path") and is used for reciprocating travel of the third transport vehicle 13. The fourth straight path 61 extends from one end of the first straight path 15 to the other side (an example of the "prescribed position of the first straight path") in the same direction as the first straight path 15 and is used for reciprocating travel of the fourth transport vehicle 60. The second merging section 62 is provided at one end of the first straight path 15 and is provided at the part where the second straight path 16B, the third straight path 17B, and the fourth straight path 61 merge.

[0129] A first receiving platform 20B for receiving material boxes 90 is provided at the second confluence section 62. The first receiving platform 20B holds material boxes 90 transported by the first transport vehicle 11, and the held material boxes 90 are then transferred to the second transport vehicle 12, the third transport vehicle 13, or the fourth transport vehicle 60. Additionally, the first receiving platform 20B holds material boxes 90 transported by the second transport vehicle 12 (or the third transport vehicle 13 or the fourth transport vehicle 60), and the held material boxes 90 are then transferred to the first transport vehicle 11 or the third transport vehicle 13 (or the second transport vehicle 12 or the fourth transport vehicle 60).

[0130] Near the end of the fourth straight path 61, and near the end on the opposite side of the second confluence 62, a fifth receiving platform 85 is provided for receiving the material box 90. The fifth receiving platform 85 holds the material box 90 transported by the fourth transport vehicle 60, or the material box 90 transported by the storage shed (not shown) and transferred to the fourth transport vehicle 60.

[0131] like Figure 2 As shown, the fourth transport vehicle 60 has the same structure as the first transport vehicle 11, the second transport vehicle 12, and the third transport vehicle 13. The fourth transport vehicle 60 consists of a vehicle body 25 with front and rear wheels 24, and a lift 26 mounted on the vehicle body 25 that supports the material box 90 for lifting. The fourth transport vehicle 60 is controlled for movement and other actions by a fourth controller 63 mounted on the ground side and a fourth vehicle body side controller 64 mounted on the side of the transport vehicle.

[0132] Similar to the article transport equipment 10F in the seventh embodiment, the first transport vehicle 11 determines its position on the first straight path 15 using two position determination devices (barcode positioning systems) consisting of a first position determination device 30B and a second position determination device 33B, which are composed of a barcode tape and a barcode reader.

[0133] The fourth transport vehicle 60 determines its position on the fourth straight path 61 by a fifth position determination device 84 consisting of a barcode strip 81 and barcode readers 82 and 83.

[0134] In the article transport device 10G of the eighth embodiment, similarly to the article transport device 10F of the seventh embodiment, when the first transport vehicle 11 travels from the other end 15A of the first straight path 15 to the second confluence section 62, at the moment when the first transport vehicle 11 travels at the position where the travel guide rail 27A and the travel guide rail 27B intersect, the position determination device switches from the first position determination device 30B to the second position determination device 33B. At the moment when the first transport vehicle 11 passes the position where the travel guide rail 27A and the travel guide rail 27B intersect, the position determination device switches from the second position determination device 33B to the first position determination device 30B again. Furthermore, when the first transport vehicle 11 travels from the second confluence section 62 to the other end 15A of the first straight path 15, at the moment when the first transport vehicle 11 travels at the position where the travel guide rail 27A and the travel guide rail 27B intersect, the position determination device switches from the second position determination device 33B to the first position determination device 30B. At the moment when the first transport vehicle 11 passes the position where the travel guide rail 27A and the travel guide rail 27B intersect, the position determination device switches from the first position determination device 30B to the second position determination device 33B again.

[0135] Furthermore, in the article transport equipment 10G of the eighth embodiment, although the second transport vehicle 12 reciprocates on the second straight path 16B and the third transport vehicle 13 reciprocates on the third straight path 17B, it is not limited to this; either the second transport vehicle 12 or the third transport vehicle 13 may reciprocate on the second straight path 16B and the third straight path 17B. Similarly, although the first transport vehicle 11 reciprocates on the first straight path 15 and the fourth transport vehicle 60 reciprocates on the fourth straight path 61, it is not limited to this; either the first transport vehicle 11 or the fourth transport vehicle 60 may reciprocate on the first straight path 15 and the fourth straight path 61.

[0136] In the article transport device 10G of the eighth embodiment, although the travel path is constituted by the travel path 14C which is approximately cross-shaped when viewed from above, it is not limited to this. The travel path can also be constituted by the travel path which is approximately X-shaped when viewed from above (a straight path composed of the first straight path 15 and the fourth straight path 61, and a straight path composed of the second straight path 16B and the third straight path 17B intersecting at a predetermined angle that is not a right angle).

[0137] In summary, based on the material handling equipment 10, 10A, 10B, 10C, 10D, 10E, 10F, and 10G, the position of the first transport vehicle 11 on the first straight path 15 is determined by switching between the first position determination devices 30, 30A, and 30B and the second position determination devices 33, 33A, and 33B. Therefore, the position of the first transport vehicle 11 can be determined based on the status of other transport vehicles besides the first transport vehicle 11 (the second transport vehicle 12, the third transport vehicle 13, and the fourth transport vehicle 60). Thus, other transport vehicles besides the first transport vehicle (the second transport vehicle 12, the third transport vehicle 13, and the fourth transport vehicle 60) will not interfere with the determination of the position of the first transport vehicle 11. Therefore, the position of the first transport vehicle 11 on the first straight path 15 (travel path) can be accurately determined.

[0138] Furthermore, in the first to eighth embodiments of this embodiment, although the operation of the first to fourth transport vehicles 11, 12, 13, and 60 is controlled by a controller installed on the ground side, it is not limited to this and can also be controlled by a vehicle-side controller installed on the transport vehicle side.

[0139] In the first to eighth embodiments of this embodiment, the positions of the first to fourth transport vehicles 11, 12, 13, and 60 are determined by either a position determination device consisting of a barcode strip and a barcode reader or a position determination device consisting of an optical device. However, this is not a limitation, and the position determination may also be performed by using both types of position determination devices.

[0140] Alternatively, as a position determination device, a magnetic device consisting of a magnetic scale and a magnetic sensor, or an optical device consisting of a scale and a photoelectric sensor, can also be used to determine the position.

Claims

1. An article transport apparatus, comprising: a first transport vehicle that transports an article; and a first straight path along which the first transport vehicle is able to travel back and forth, characterized by comprising: a second straight path that is provided so as to extend from a prescribed position of the first straight path in a direction that includes the prescribed position of the first straight path and intersects the first straight path, and a second transport vehicle that is able to travel back and forth on the second straight path and hand over the article between the first transport vehicle and the prescribed position of the first straight path, the article transport apparatus comprising: a first position determination device; and a second position determination device, the first position determination device comprising: a first determination target object that is provided on a ground surface on which the first straight path including the prescribed position is provided; and a first reading device that is provided on the first transport vehicle and reads a position of the first transport vehicle on the first straight path including the prescribed position by cooperating with the first determination target object, the second position determination device comprising: a second determination target object that is provided on the ground surface on which the first straight path is provided at a position different from the position at which the first determination target object is provided and at a position other than the prescribed position; and a second reading device that is provided on the first transport vehicle and reads a position of the first transport vehicle on the first straight path by cooperating with the second determination target object, and the first reading device and the second reading device are switched on the first straight path.

2. The article transport apparatus according to claim 1, characterized in that the first determination target object and the second determination target object are constituted by markers that are provided along the first straight path and that are used to determine a position of the first transport vehicle on the first straight path.

3. The article transport apparatus according to claim 1, characterized in that the first position determination device and the second position determination device are constituted by optical devices.

4. The article transport apparatus according to any one of claims 1 to 3, characterized in that the first transport vehicle corrects a difference between a detection value of the first position determination device and a detection value of the second position determination device at the time of switching the first reading device and the second reading device, and thereby determines a position of the first transport vehicle on the first straight path. ​ ​ ​ ​ ​ ​ ​ ​

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