Article handling equipment

Abstract

The travel unit travels in a curved section with the target wheel in contact with the target rail, the guide wheel in contact with the guide rail, and the non-target wheel not in contact with the non-target rail. The control unit changes the rotational speeds of the first and second wheels in the curved section relative to the rotational speeds of the first and second wheels in the straight section in accordance with a ratio of a second length, which is a length along the travel path of the target rail, to a first length, which is a length along the travel path of the curved section at the center portion in the width direction of the travel path.

Description

Technical Field

[0001] The present invention relates to article transport equipment including travel rails arranged along a travel path, a transport vehicle that travels along the travel rails to transport articles, and a control unit that controls the travel operation of a travel unit of the transport vehicle. Background Art

[0002] An example of an article handling device as described above is disclosed in Japanese Patent Publication No. 2010-282569 (Patent Document 1). In the following, the reference numerals in brackets in the description of the background art are reference numerals of Patent Document 1. The article handling device of Patent Document 1 comprises a travel track (4), a transport vehicle (3) that travels along the travel track (4), and a travel control unit (59) that controls the travel of the transport vehicle (3). The transport vehicle (3) comprises a first drive wheel (25) driven by a first motor (26) and a second drive wheel (28) driven by a second motor (29). As described in paragraphs 0052-0054 of Patent Document 1, when the transport vehicle (3) travels in the curved portion (8), the center speed of the transport vehicle (3) is made consistent with the prescribed speed by decelerating the inner wheels of the first drive wheel (25) and the second drive wheel (28) and accelerating the outer wheels.

[0003] However, unlike the transport vehicle of Patent Document 1, there are cases where the left and right wheels of the transport vehicle (the first drive wheel and the second drive wheel of Patent Document 1) are driven to rotate at the same speed. In this case, the transport vehicle must also be able to properly travel in a curved section where the travel path is curved when viewed from above. However, Patent Document 1 does not describe this point. Summary of the Invention

[0004] Therefore, it is desired to realize article transport equipment that enables a transport vehicle to properly travel in a curved section when both left and right wheels of the transport vehicle are driven to rotate at the same speed.

[0005] The article handling equipment of the present application includes a travel track, a transport vehicle, and a control unit, wherein the travel track is arranged along a travel path, the transport vehicle travels along the travel track to transport articles, and the control unit controls the travel operation of the travel unit of the transport vehicle, the article handling equipment being characterized in that the travel path includes a straight section formed as a straight line when viewed from above and a curved section formed as a curve when viewed from above, in the straight section, two travel tracks, namely a first travel track and a second travel track, are arranged on both sides of a central part in the width direction of the travel path, one of the first travel track and the second travel track is set as an object track, and the other is set as a non-object track, in the curved section, at least the object track of the object track and the non-object track is arranged, and a guide rail other than the object track and the non-object track is arranged along the travel path, and the travel unit includes a first wheel rolling on a travel surface of the first travel track, a second wheel rolling on a travel surface of the second travel track. a wheel, a driving unit for rotating the first wheel and the second wheel at the same speed, and a guide wheel rolling on a guide surface of the guide rail; the first wheel being a target wheel when the target rail is the first travel rail, and the second wheel being a target wheel when the target rail is the second travel rail; and the one of the first wheel and the second wheel that is not the target wheel being a non-target wheel; the travel unit traveling in the curved section in a posture in which the target wheel is in contact with the target rail, the guide wheel is in contact with the guide rail, and the non-target wheel is not in contact with the non-target rail; the control unit changing the rotational speed of the first wheel and the second wheel in the curved section relative to the rotational speed of the first wheel and the second wheel in the straight section based on a ratio of a first length, which is a length of the curved section along the travel path, to a second length, which is a length of the target rail along the travel path, relative to a center portion in the width direction of the travel path.

[0006] According to this solution, the transport unit maintains a posture when traveling in a curved section, with the target wheel in contact with the target rail, the guide wheel in contact with the guide rail, and the non-target wheel not in contact with the non-target rail. Therefore, in a curved section where the lengths of the target wheel's and non-target wheel's moving paths differ, the target wheel and non-target wheel can rotate at the same speed, allowing the transport vehicle to travel appropriately. In other words, according to this solution, the transport vehicle can travel appropriately in a curved section by driving both its left and right wheels at the same speed.

[0007] Furthermore, in this embodiment, the rotational speeds of the first and second wheels in the curved section vary in accordance with the ratio of the second length to the first length relative to the rotational speeds of the first and second wheels in the straight section. Here, the ratio of the second length to the first length is the same as or substantially the same as the ratio of the moving speed of the target wheel relative to the moving speed of the center portion of the transport vehicle (the center portion in the width direction, the same applies hereinafter). Therefore, by setting the rotational speeds of the first and second wheels in the curved section as described above, the moving speed of the center portion of the transport vehicle in the curved section can be made close to the moving speed of the center portion of the transport vehicle in the straight section. As a result, the speed change of the center portion of the transport vehicle when passing through the boundary between the straight section and the curved section can be suppressed to a small value, and the vibration that occurs in the transport vehicle and the items being transported by the transport vehicle can be suppressed to a small value.

[0008] Furthermore, unlike this embodiment, when the rotational speeds of the first and second wheels in the curved section are not changed relative to the rotational speeds of the first and second wheels in the straight section, the moving speed of the central portion of the transport vehicle in the curved section, where the target track is on the inner circumference, becomes higher than the moving speed of the central portion of the transport vehicle in the straight section. Therefore, in order to suppress the moving speed of the central portion of the transport vehicle in the curved section to below the maximum permissible speed, it is necessary to suppress the moving speed of the central portion of the transport vehicle in the straight section to a lower level. In contrast, according to this embodiment, the moving speed of the central portion of the transport vehicle in the curved section can be brought closer to the moving speed of the central portion of the transport vehicle in the straight section, thus reducing such a need and shortening the time required for the transport vehicle to travel along a path that includes both straight and curved sections.

[0009] Further features and advantages of the article transport facility will become more apparent from the following description of the embodiments described with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 It is a three-dimensional diagram of a transport truck.

[0011] Figure 2 This is the front view of the traveling section.

[0012] Figure 3 It is a control block diagram.

[0013] Figure 4 is a top view of a portion of the travel path.

[0014] Figure 5 This is a top view of the transport vehicle located in the straight section.

[0015] Figure 6 This is a top view of the transport vehicle located at the boundary between the straight section and the curved section.

[0016] Figure 7 This diagram shows the scene of a transport truck passing through a curved section in chronological order.

[0017] Figure 8 3 is a graph showing time changes in the moving speed and moving acceleration of the second target wheel of the comparative example.

[0018] Figure 9 3 is a graph showing time changes in the moving speed and moving acceleration of the first target wheel of the comparative example.

[0019] Figure 10 Graph showing temporal changes in the moving speed and moving acceleration of the central portion of a transport vehicle according to a comparative example.

[0020] Figure 11 This is a graph showing time changes in the moving speed and moving acceleration of the second target wheel in the embodiment.

[0021] Figure 12 This is a graph showing time changes in the moving speed and moving acceleration of the first target wheel in the embodiment.

[0022] Figure 13 This is a graph showing time changes in the moving speed and moving acceleration of the central portion of the transport vehicle according to the embodiment.

[0023] Figure 14 This is a diagram showing an example of speed weight and speed weight change rate.

[0024] Figure 15 This is a diagram showing other examples of speed weight and speed weight change rate.

[0025] Figure 16 is with Figure 14 and Figure 15 Corresponding graph showing the time variation of the moving acceleration of the center portion of the transport vehicle. DETAILED DESCRIPTION

[0026] The embodiment of the article handling equipment will be described with reference to the accompanying drawings. Figure 1 As shown, the article transport facility 100 includes a travel track 80 arranged along a travel path 70 and a transport vehicle 1 that travels along the travel track 80 to transport an article 2. Figure 1 As shown, the long side direction of the travel path 70 (the direction in which the travel path 70 extends) is referred to as the long side direction X, and the width direction of the travel path 70 is referred to as the width direction Y. The width direction Y is a direction perpendicular to both the long side direction X and the vertical direction Z. Figure 4As shown, in this embodiment, the travel direction T of the transport vehicle 1 on the travel path 70 is set to one direction, with the front side of the transport vehicle 1 in the longitudinal direction X of the path being the downstream side X1, and the rear side of the transport vehicle 1 in the longitudinal direction X being the upstream side X2. In this embodiment, the path width direction Y corresponds to the "width direction."

[0027] In this embodiment, the transport vehicle 1 is a ceiling transport vehicle that travels along a travel path 70 formed along the ceiling. Therefore, although the illustration is omitted, the travel rail 80 and the guide rail 83 described later (see FIG. Figure 2 ) is supported, for example, by being suspended from the ceiling. Alternatively, the transport vehicle 1 may be a transport vehicle other than a ceiling transport vehicle. Furthermore, the type of object 2 is not limited thereto. For example, the object 2 may be a front-opening unified pod (FOUP) that accommodates semiconductor wafers.

[0028] like Figure 4 As shown, the travel path 70 includes a straight section 71 that is formed into a straight line when viewed from above (viewed in the direction of the vertical direction Z), and a curved section 72 that is formed into a curved line when viewed from above. In the straight section 71, a first travel track 81 and a second travel track 82 are arranged as two travel tracks 80. The first travel track 81 and the second travel track 82 are arranged to be divided into two sides relative to the central portion 70a in the path width direction Y of the travel path 70. In the straight section 71, the center position in the path width direction Y between the first travel track 81 and the second travel track 82 is the central portion 70a in the path width direction Y of the travel path 70. Hereinafter, the side close to the central portion 70a in the path width direction Y is referred to as the inner side in the path width direction Y, and the side away from the central portion 70a in the path width direction Y is referred to as the outer side in the path width direction Y.

[0029] One of the first and second travel rails 81 and 82 is designated as the target rail 80A, and the other is designated as the non-target rail 80B. At least the target rail 80A of the target rail 80A and the non-target rail 80B is disposed in the curved section 72. The distance between the first and second travel rails 81 and 82 in the straight section 71 in the path width direction Y is designated as the path width, and the target rail 80A is disposed at a position where the distance from the center portion 70a in the path width direction Y of the path 70 is half the path width. Figure 4 As shown in the example shown, the target track 80A is the one that is arranged on the inner side (closer to the center of rotation) in the curve section 72 of the first travel track 81 and the second travel track 82 ( Figure 4In the case where the target rail 80A is the first travel rail 81, the position that is half the travel path width outward (away from the center of rotation) from the target rail 80A is the center portion 70a of the travel path 70 in the path width direction Y. On the other hand, in the case where the target rail 80A is arranged on the outer side of the curved section 72 of the first travel rail 81 and the second travel rail 82, the position that is half the travel path width inward from the target rail 80A is the center portion 70a of the travel path 70 in the path width direction Y.

[0030] Figure 4 In the example shown, in the curve section 72, in addition to the target track 80A, a non-target track 80B ( Figure 4 The second travel track 82 is in the middle. The non-target track 80B is arranged at a position where the distance from the center portion 70a of the travel path 70 in the path width direction Y is half the path width. When both the target track 80A and the non-target track 80B are arranged in the curved section 72, the center position of the target track 80A and the non-target track 80B in the path width direction Y is the center portion 70a of the path width direction Y of the travel path 70. Figure 4 The curved section 72 shown connects the respective ends of the two straight sections 71 , but the curved section 72 may be provided so as to branch off from the straight section 71 and merge with the straight section 71 .

[0031] Figure 4 Although omitted, Figure 2 、 Figure 5 and Figure 6 As shown, in the curved section 72, the guide rail 83 excluding the target rail 80A and the non-target rail 80B is arranged along the travel path 70. Here, the guide rail 83 is arranged at the center portion 70a of the travel path 70 in the path width direction Y. Figure 1 、 Figure 5 and Figure 6 As shown, the guide rail 83 is not arranged in the straight section 71 .

[0032] like Figure 1 As shown, the transport vehicle 1 includes a first traveling portion 11. In this embodiment, the transport vehicle 1 further includes a second traveling portion 12. The second traveling portion 12 is arranged on the front side L1 of the vehicle body front-back direction L relative to the first traveling portion 11. In other words, the first traveling portion 11 is arranged on the rear side L2 of the vehicle body front-back direction L relative to the second traveling portion 12. The vehicle body front-back direction L is a direction defined with the transport vehicle 1 as a reference (i.e., as shown in FIG. 1 ). Figure 5 and Figure 6The transport vehicle 1 is arranged on the travel path 70 with the vehicle body front-back direction L along the long side direction X of the path. That is, the vehicle body front-back direction L is a direction along the travel path 70. In the curved section 72, the transport vehicle 1 is arranged on the travel path 70 with the vehicle body front-back direction L along the tangent direction of the long side direction X of the curved path when viewed from above. The direction defined with the transport vehicle 1 as a reference and along the vertical direction Z in the state where the transport vehicle 1 is arranged in the straight section 71 is referred to as the vehicle body up-down direction H. The direction connecting the first axis A1 and the second axis A2 described later when viewed in the direction along the vehicle body up-down direction H (refer to Figure 5 ) is the vehicle body front-rear direction L. In this embodiment, the first traveling portion 11 corresponds to the "traveling portion", the vehicle body front-rear direction L corresponds to the "front-rear direction", and the vehicle body up-down direction H corresponds to the "up-down direction".

[0033] The transport vehicle 1 includes a main body 13 connected to the first travel portion 11. In the present embodiment, the main body 13 is supported by the first travel portion 11 while being arranged at the lower side Z1 in the vertical direction Z relative to the first travel portion 11. In the present embodiment, the main body 13 is also connected to the second travel portion 12, and the main body 13 is supported by the first travel portion 11 and the second travel portion 12 while being arranged at the lower side Z1 relative to the first travel portion 11 and the second travel portion 12. That is, the transport vehicle 1 includes a main body 13 connected to the first travel portion 11 and the second travel portion 12. Although detailed description is omitted, the main body 13 includes a support portion that supports the article 2, and the article 2 is transported by the transport vehicle 1 while being supported by the main body 13.

[0034] like Figure 1 As shown, the first travel section 11 includes a first wheel 21 that rolls on the travel surface of the first travel rail 81, a second wheel 22 that rolls on the travel surface of the second travel rail 82, a first driving unit M1 (for example, an electric motor such as a servo motor) that rotates the first wheel 21 and the second wheel 22 at the same speed, and a first guide wheel 41 that rolls on the guide surface of the guide rail 83. The travel surface of the first travel rail 81 and the travel surface of the second travel rail 82 are surfaces facing the upper side Z2 in the vertical direction Z ( Figure 2 In the example shown, the guide surface of the guide rail 83 is a surface facing one side in the path width direction Y ( Figure 2In the example shown, a vertical plane is used). In the present embodiment, a first wheel 21 is provided, a second wheel 22 is provided, and two first guide wheels 41 are provided so as to be arranged in the vehicle body front-rear direction L. The first wheel 21 and the second wheel 22 rotate around an axis perpendicular to the vehicle body up-down direction H, and the first guide wheel 41 rotates around an axis along the vehicle body up-down direction H (idling in this example). The first wheel 21 and the second wheel 22 are formed to have the same diameter as each other. The first wheel 21 and the second wheel 22 are rotationally driven by the first drive unit M1, whereby the first travel unit 11 travels along the travel track 80. In the present embodiment, the first drive unit M1 is equivalent to the "drive unit", and the first guide wheel 41 is equivalent to the "guide wheel".

[0035] like Figure 1 As shown, the second traveling portion 12 includes a third wheel 23 that rolls on the traveling surface of the first traveling rail 81, a fourth wheel 24 that rolls on the traveling surface of the second traveling rail 82, and a second guide wheel 42 that rolls on the guide surface of the guide rail 83. In this embodiment, one third wheel 23 is provided, one fourth wheel 24 is provided, and two second guide wheels 42 are provided so as to be arranged in the vehicle body front-to-back direction L. The third wheel 23 and the fourth wheel 24 rotate around an axis that is perpendicular to the vehicle body up-down direction H, and the second guide wheel 42 rotates around an axis along the vehicle body up-down direction H (in this example, it idles). The third wheel 23 and the fourth wheel 24 are formed to have the same diameter as each other. In this embodiment, the second traveling portion 12 further includes a second driving portion M2 (for example, an electric motor such as a servo motor) that causes the third wheel 23 and the fourth wheel 24 to rotate at the same speed. The third and fourth wheels 23 and 24 are rotationally driven by the second drive unit M2, whereby the second travel unit 12 travels along the travel rail 80. Alternatively, the second travel unit 12 may not include the second drive unit M2, and the third and fourth wheels 23 and 24 may idle.

[0036] like Figure 1 As shown, the first traveling unit 11 travels in the straight section 71 with the first wheel 21 in contact with the first travel rail 81, the second wheel 22 in contact with the second travel rail 82, and the first guide wheel 41 not in contact with the guide rail 83. The second traveling unit 12 travels in the straight section 71 with the third wheel 23 in contact with the first travel rail 81, the fourth wheel 24 in contact with the second travel rail 82, and the second guide wheel 42 not in contact with the guide rail 83. Since the guide rail 83 is not provided in the straight section 71, the first guide wheel 41 does not contact the guide rail 83 when the first traveling unit 11 travels in the straight section 71, and the second guide wheel 42 does not contact the guide rail 83 when the second traveling unit 12 travels in the straight section 71.

[0037] When the target track 80A is the first travel track 81, the first wheel 21 is set as the first target wheel 31A. When the target track 80A is the second travel track 82, the second wheel 22 is set as the first target wheel 31A. The first wheel 21 and the second wheel 22 that are not the first target wheel 31A are set as the first non-target wheel 31B. Figure 2 As shown, the first traveling unit 11 travels in the curved section 72 with the first target wheel 31A in contact with the target rail 80A, the first guide wheels 41 (in this embodiment, both first guide wheels 41) in contact with the guide rail 83, and the first non-target wheel 31B not in contact with the non-target rail 80B. Since the first target wheel 31A is in contact with the target rail 80A and the first guide wheels 41 are in contact with the guide rail 83, even when the non-target rail 80B is positioned in the curved section 72, the first traveling unit 11 maintains a posture in which the first non-target wheel 31B is not in contact with the non-target rail 80B (in other words, the first non-target wheel 31B is separated from the non-target rail 80B). Figure 2 In the example shown, the target track 80A is the first travel track 81, so the first wheel 21 is the first target wheel 31A, and the second wheel 22 is the first non-target wheel 31B. In this embodiment, the first target wheel 31A corresponds to the "target wheel" and the first non-target wheel 31B corresponds to the "non-target wheel."

[0038] When the first wheel 21 is the first target wheel 31A, the third wheel 23 is set as the second target wheel 32A. When the second wheel 22 is the first target wheel 31A, the fourth wheel 24 is set as the second target wheel 32A. The one of the third wheel 23 and the fourth wheel 24 that is not the second target wheel 32A is set as the second non-target wheel 32B. Although not shown in the figure, the second traveling section 12 travels in the curved section 72 in a posture in which the second target wheel 32A is in contact with the target rail 80A, the second guide wheel 42 (in this embodiment, two second guide wheels 42) are in contact with the guide rail 83, and the second non-target wheel 32B is not in contact with the non-target rail 80B. The second target wheel 32A is in contact with the target rail 80A, and the second guide wheel 42 is in contact with the guide rail 83. Thus, when the non-target rail 80B is arranged in the curved section 72, the posture of the second traveling portion 12 is also maintained in a posture in which the second non-target wheel 32B is not in contact with the non-target rail 80B (in other words, the second non-target wheel 32B is separated from the non-target rail 80B). Figure 5 and Figure 6 In the example shown, the first wheel 21 is the first target wheel 31A, so the third wheel 23 is the second target wheel 32A, and the fourth wheel 24 is the second non-target wheel 32B.

[0039] like Figures 4 to 6 In the example shown, when the target track 80A is arranged on the inner side of the curved section 72 among the first travel track 81 and the second travel track 82 (i.e., the target track 80A is the curved section 72 on the inner circumference side), the first guide wheel 41 and the second guide wheel 42 contact the guide track 83 from the inner side. On the other hand, when the target track 80A is arranged on the outer side of the curved section 72 among the first travel track 81 and the second travel track 82 (i.e., the target track 80A is the curved section 72 on the outer circumference side), the first guide wheel 41 and the second guide wheel 42 contact the guide track 83 from the outer side. Figure 1 As shown, in this embodiment, the first travel section 11 includes a third drive unit M3 (e.g., a solenoid or an electric motor) that moves the first guide wheel 41 in the width direction of the first travel section 11 (the direction in which the first wheel 21 and the second wheel 22 are arranged), and the second travel section 12 includes a fourth drive unit M4 (e.g., a solenoid or an electric motor) that moves the second guide wheel 42 in the width direction of the second travel section 12 (the direction in which the third wheel 23 and the fourth wheel 24 are arranged). By driving the third drive unit M3 and the fourth drive unit M4, the positions of the first guide wheel 41 and the second guide wheel 42 are switched between a position in which they are arranged inside the guide rail 83 and contact the guide rail 83 from the inside, and a position in which they are arranged outside the guide rail 83 and contact the guide rail 83 from the outside.

[0040] In this embodiment, the guide rail 83 is arranged so that the posture of the transport vehicle 1 in the curved section 72 is the same as that in the straight section 71, with the vehicle body up-down direction H along the vertical direction Z. Figure 2 As shown, the first traveling portion 11 travels in the curved section 72 with the first wheel 21 and the second wheel 22 arranged at the same height (position in the vertical direction Z) (with the first axis A1 described later along the vertical direction Z). Although not shown in the figure, the second traveling portion 12 travels in the curved section 72 with the third wheel 23 and the fourth wheel 24 arranged at the same height (with the second axis A2 described later along the vertical direction Z). In addition, Figure 2 In the illustrated example, in the curved section 72 , the non-target track 80B is arranged at the same height as the target track 80A. Figure 2 In the example shown, a recessed portion that is recessed downward Z1 is provided along the longitudinal direction X of the path in a portion of the upper surface of the non-target rail 80B that faces the first non-target wheel 31B and the second non-target wheel 32B in the vertical direction Z. This allows the transport vehicle 1 in the curved section 72 to be positioned such that the vehicle body vertical direction H is aligned with the vertical direction Z, and prevents the first non-target wheel 31B and the second non-target wheel 32B from contacting the non-target rail 80B.

[0041] In this embodiment, if Figure 5 and Figure 6 As shown, the first traveling portion 11 is rotatably connected to the main body 13 around the first axis A1 along the vehicle body vertical direction H, and the second traveling portion 12 is rotatably connected to the main body 13 around the second axis A2 along the vehicle body vertical direction H. Figure 6 and Figure 7 As shown, when the transport vehicle 1 sequentially travels through a straight section 71, a curved section 72, and another straight section 71, the postures of the first travel section 11 and the second travel section 12 (the postures about the axis along the vehicle body vertical direction H) are appropriately changed, allowing the transport vehicle 1 to travel smoothly. Furthermore, the first axis A1 and the second axis A2 are both imaginary axes. The first axis A1 is located at the center of the first travel section 11 in the width direction (the width direction of the first travel section 11), and the second axis A2 is located at the center of the second travel section 12 in the width direction (the width direction of the second travel section 12).

[0042] like Figure 2 and Figure 5 As shown, in this embodiment, the first travel portion 11 includes a first auxiliary wheel 51 that rolls on the guide surface of the first travel rail 81, and a second auxiliary wheel 52 that rolls on the guide surface of the second travel rail 82. The guide surface of the first travel rail 81 and the guide surface of the second travel rail 82 are surfaces facing the inner side of the path width direction Y (vertical surfaces in this example). In this embodiment, two first auxiliary wheels 51 are arranged in a manner arranged along the front-rear direction L of the vehicle body, and two second auxiliary wheels 52 are arranged in a manner arranged along the front-rear direction L of the vehicle body. In addition, as shown in FIG. Figure 5 As shown, in this embodiment, the second travel portion 12 includes a third auxiliary wheel 53 that rolls on the guide surface of the first travel rail 81, and a fourth auxiliary wheel 54 that rolls on the guide surface of the second travel rail 82. In this embodiment, two third auxiliary wheels 53 are provided so as to be aligned in the vehicle body front-to-back direction L, and two fourth auxiliary wheels 54 are provided so as to be aligned in the vehicle body front-to-back direction L.

[0043] When the first traveling portion 11 is located in the straight section 71, Figure 5 As shown, the first auxiliary wheels 51 (two first auxiliary wheels 51 in this embodiment) are in contact with the first travel rail 81, and the second auxiliary wheels 52 (two second auxiliary wheels 52 in this embodiment) are in contact with the second travel rail 82. As a result, the rotation of the first travel portion 11 about the first axis A1 is restricted by the first travel rail 81 and the second travel rail 82, and the posture of the first travel portion 11 is maintained so that the front-to-back direction of the first travel portion 11 (a direction orthogonal to both the width direction of the first travel portion 11 and the vehicle body up-down direction H) is along the longitudinal direction X of the path.

[0044] In addition, when the first wheel 21 is the first target wheel 31A, the first auxiliary wheel 51 is set as the first target auxiliary wheel, and when the second wheel 22 is the first target wheel 31A, the second auxiliary wheel 52 is set as the first target auxiliary wheel. When the first traveling portion 11 is located in the curved section 72, as shown in FIG. Figure 2 As shown, the first object auxiliary wheel (two first object auxiliary wheels in this embodiment) is in contact with the object track 80A, and the first guide wheel 41 is in contact with the guide track 83. As a result, the rotation of the first traveling portion 11 around the first axis A1 is restricted by the object track 80A and the guide track 83, and the posture of the first traveling portion 11 is maintained in a posture in which the front-to-back direction of the first traveling portion 11 is along the long side direction X of the path (specifically, the tangent direction of the long side direction X of the curved path). Figure 2 As shown in the example shown, when the non-object track 80B is arranged in the curved section 72, the one of the first auxiliary wheel 51 and the second auxiliary wheel 52 that is not the first object auxiliary wheel is set as the first non-object auxiliary wheel, and the rotation of the first traveling portion 11 around the first axis A1 is also restricted by the first non-object auxiliary wheel (in this embodiment, two first non-object auxiliary wheels) contacting the non-object track 80B.

[0045] When the second travel section 12 is located in the straight section 71, the third auxiliary wheels 53 (in this embodiment, the two third auxiliary wheels 53) are in contact with the first travel rail 81, and the fourth auxiliary wheels 54 (in this embodiment, the two fourth auxiliary wheels 54) are in contact with the second travel rail 82. As a result, the rotation of the second travel section 12 about the second axis A2 is restricted by the first travel rail 81 and the second travel rail 82, and the posture of the second travel section 12 is maintained so that the front-to-back direction of the second travel section 12 (a direction orthogonal to both the width direction of the second travel section 12 and the vehicle body vertical direction H) is along the longitudinal direction X of the path.

[0046] In addition, when the third wheel 23 is the second target wheel 32A, the third auxiliary wheel 53 is set as the second target auxiliary wheel, and when the fourth wheel 24 is the second target wheel 32A, the fourth auxiliary wheel 54 is set as the second target auxiliary wheel. When the second traveling portion 12 is located in the curved section 72, as shown in FIG. Figure 6 As shown, the second object auxiliary wheel (two second object auxiliary wheels in this embodiment) is in contact with the object rail 80A, and the second guide wheel 42 is in contact with the guide rail 83. As a result, the rotation of the second travel portion 12 around the second axis A2 is restricted by the object rail 80A and the guide rail 83, and the posture of the second travel portion 12 is maintained in a posture in which the front-to-back direction of the second travel portion 12 is along the long side direction X of the path (specifically, the tangent direction of the long side direction X of the curved path). Figure 6In the example shown, when the non-object track 80B is configured in the curved section 72, the one of the third auxiliary wheel 53 and the fourth auxiliary wheel 54 that is not the second object auxiliary wheel is set as the second non-object auxiliary wheel, and the rotation of the second traveling portion 12 around the second axis A2 is also restricted by the second non-object auxiliary wheel (in this embodiment, two second non-object auxiliary wheels) contacting the non-object track 80B.

[0047] like Figure 3 As shown, the article handling equipment 100 includes a control unit 60. The control unit 60 includes an arithmetic processing device such as a central processing unit and peripheral circuits such as a memory, and the various functions of the control unit 60 are realized through the cooperation of these hardware and the programs executed on the hardware such as the arithmetic processing device. The control unit 60 can be set in the transport vehicle 1, or it can be set independently of the transport vehicle 1. In addition, when the control unit 60 includes a plurality of hardware that can be separated and communicated with each other, part of the hardware can be set in the transport vehicle 1, and the remaining hardware can be set independently of the transport vehicle 1. The technical features of the control unit 60 disclosed in this specification can also be applied to the control method of the transport vehicle 1 of the article handling equipment 100, and the control method of the transport vehicle 1 is also disclosed in this specification.

[0048] The control unit 60 controls the travel of the first travel unit 11. In this embodiment, the control unit 60 also controls the travel of the second travel unit 12. Specifically, the control unit 60 controls the travel of the first travel unit 11 by controlling the driving of the first drive unit M1, and controls the travel of the second travel unit 12 by controlling the driving of the second drive unit M2. Furthermore, when the transport vehicle 1 enters a curved section 72, the control unit 60 controls the driving of the third drive unit M3 and the fourth drive unit M4 to switch the positions of the first guide wheels 41 and the second guide wheels 42 according to the structure of the curved section 72. Specifically, the control unit 60 moves the first guide wheel 41 and the second guide wheel 42 to a position contacting the guide rail 83 from the inside when the object track 80A configured in the curved section 72 for entering the destination is the inner side of the curved section 72 of the first travel track 81 and the second travel track 82, and moves the first guide wheel 41 and the second guide wheel 42 to a position contacting the guide rail 83 from the outside when the object track 80A configured in the curved section 72 is the outer side of the curved section 72 of the first travel track 81 and the second travel track 82.

[0049] In the present embodiment, the control unit 60 is configured to control the rotational speed of the first wheel 21 and the second wheel 22 in a manner consistent with the target rotational speed, so that the first traveling unit 11 travels. Specifically, the control unit 60 generates a drive instruction for making the rotational speed of the first wheel 21 and the second wheel 22 consistent with the target rotational speed, and outputs the drive instruction to the first driving unit M1. The drive instruction is a speed instruction or a position instruction. The position instruction is generated by, for example, integrating the speed instruction. The first driving unit M1 includes a motor unit for rotating the first wheel 21 and the second wheel 22, and an amplifier unit for feedback-controlling the driving motor unit in a manner that follows the drive instruction input from the control unit 60, so that the first wheel 21 and the second wheel 22 rotate in a manner that makes the rotational speed of the first wheel 21 and the second wheel 22 consistent with the target rotational speed.

[0050] In this embodiment, the control unit 60 is configured to cause the second traveling unit 12 to travel in a manner slaved to the travel of the first traveling unit 11. Specifically, the control unit 60 slave-controls the drive states of the third and fourth wheels 23, 24 of the second driving unit M2 in accordance with the drive states of the first and second wheels 21, 22 of the first driving unit M1, thereby causing the second traveling unit 12 to travel in a manner slaved to the travel of the first traveling unit 11. For example, the control unit 60 controls the drive torque of the third and fourth wheels 23, 24 of the second driving unit M2 so that the second traveling unit 12 travels in a manner slaved to the travel of the first traveling unit 11. Alternatively, the control unit 60 controls the drive torque of the third and fourth wheels 23, 24 of the second driving unit M2 to zero (no torque control), thereby causing the second traveling unit 12 to travel in a manner slaved to the travel of the first traveling unit 11.

[0051] However, when the transport vehicle 1 passes through the boundary B between the straight section 71 and the curved section 72 of the travel path 70, if the speed change in the center portion (the center portion in the path width direction Y, the same applies hereinafter) of the transport vehicle 1 becomes large, the transport vehicle 1 or the article 2 transported by the transport vehicle 1 is likely to vibrate. Figure 4 As shown, the boundary B between the curved section 72 and the straight section 71 on the upstream side X2 relative to the curved section 72 is set as the first boundary B1, and the boundary B between the curved section 72 and the straight section 71 on the downstream side X1 relative to the curved section 72 is set as the second boundary B2. For example, if the rotation speeds of the first wheel 21 and the second wheel 22 in the curved section 72 are not changed relative to the rotation speeds of the first wheel 21 and the second wheel 22 in the straight section 71, as shown in FIG. Figures 8 to 10 As shown in the calculation results, the speed change of the center of the transport vehicle 1 becomes larger when passing through the boundary B. Here, it is assumed that the transport vehicle 1 enters Figures 4 to 6 As shown in the figure, the curvature is constant and the curve section 72 is exited. Figure 8 (and referenced later Figure 11 ) represents the temporal change of the moving speed and moving acceleration of the second target wheel 32A, Figure 9 (and referenced later Figure 12 ) represents the temporal changes in the moving speed and moving acceleration of the first target wheel 31A, Figure 10 (and referenced later Figure 13 ) represents the temporal changes in the moving speed and acceleration at the center of the transport vehicle 1 (specifically, the midpoint of the line segment connecting the first axis A1 and the second axis A2 when viewed in the vehicle body vertical direction H). Note that these moving speeds and accelerations are those along the travel path 70.

[0052] From the time when the transport vehicle 1 enters the curve section 72 to the time when it exits, Figure 7 As shown, the posture of the transport vehicle 1 changes in sequence to the 0th posture P0, the 1st posture P1, the 2nd posture P2, the 3rd posture P3, the 4th posture P4, the 5th posture P5, the 6th posture P6, and the 7th posture P7. The 0th posture P0 is the posture of the transport vehicle 1 when the third auxiliary wheel 53 on the front side L1 of the two third auxiliary wheels 53 reaches the first boundary B1. The 1st posture P1 is the posture of the transport vehicle 1 when the third auxiliary wheel 53 on the rear side L2 of the two third auxiliary wheels 53 reaches the first boundary B1. The 2nd posture P2 is the posture of the transport vehicle 1 when the first auxiliary wheel 51 on the front side L1 of the two first auxiliary wheels 51 reaches the first boundary B1. The 3rd posture P3 is the posture of the transport vehicle 1 when the first auxiliary wheel 51 on the rear side L2 of the two first auxiliary wheels 51 reaches the first boundary B1. The fourth posture P4 is the posture of the transport vehicle 1 at the moment when the third auxiliary wheel 53 on the front side L1 of the two third auxiliary wheels 53 reaches the second boundary B2. The fifth posture P5 is the posture of the transport vehicle 1 at the moment when the third auxiliary wheel 53 on the rear side L2 of the two third auxiliary wheels 53 reaches the second boundary B2. The sixth posture P6 is the posture of the transport vehicle 1 at the moment when the first auxiliary wheel 51 on the front side L1 of the two first auxiliary wheels 51 reaches the second boundary B2. The seventh posture P7 is the posture of the transport vehicle 1 at the moment when the first auxiliary wheel 51 on the rear side L2 of the two first auxiliary wheels 51 reaches the second boundary B2. Figures 8 to 10 , and the following references Figures 11 to 13 、 Figure 16 In FIG, vertical lines are shown when the transport vehicle 1 is in each of the 0th posture P0 to the 7th posture P7. Figure 7In the embodiment, it is assumed that the first wheel 21 is the first target wheel 31A and the third wheel 23 is the second target wheel 32A, but the second wheel 22 is the first target wheel 31A and the fourth wheel 24 is the second target wheel 32A. Under the definition of each posture described above, the first auxiliary wheel 51 can be replaced by the second auxiliary wheel 52, and the third auxiliary wheel 53 can be replaced by the fourth auxiliary wheel 54, thereby defining each posture of the transport vehicle 1 in the same manner as described above.

[0053] Figures 8 to 10 In the embodiment, the rotational speeds of the first wheel 21 and the second wheel 22 in the straight section 71 are set so that the moving speed of the center portion of the transport vehicle 1 is the first speed V1, and it is assumed that the rotational speeds of the first wheel 21 and the second wheel 22 in the curved section 72 are not changed relative to the rotational speeds of the first wheel 21 and the second wheel 22 in the straight section 71. Therefore, if Figure 9 As shown, while the posture of the transport vehicle 1 changes from the 0th posture P0 to the 7th posture P7, the rotational speed of the first target wheel 31A is maintained at the rotational speed in the straight section 71. As a result, the moving speed of the first target wheel 31A determined corresponding to the rotational speed of the first target wheel 31A is maintained at the first speed V1.

[0054] On the other hand, Figure 10 As shown, the moving speed of the central portion of the transport vehicle 1 is not maintained at the first speed V1 during the period when the posture of the transport vehicle 1 changes from the 0th posture P0 to the 7th posture P7. The moving speed of the central portion of the transport vehicle 1 changes at a relatively large acceleration during the period when the posture of the transport vehicle 1 changes from the 2nd posture P2 to the 3rd posture P3 and during the period when the posture of the transport vehicle 1 changes from the 6th posture P6 to the 7th posture P7. Here, the target track 80A arranged in the curved section 72 is arranged on the inner side of the curved section 72 between the first travel track 81 and the second travel track 82, so the moving speed of the central part of the transport vehicle 1 increases during the period when the posture of the transport vehicle 1 changes from the second posture P2 to the third posture P3, and the moving speed of the central part of the transport vehicle 1 decreases during the period when the posture of the transport vehicle 1 changes from the sixth posture P6 to the seventh posture P7. However, in the case where the target track 80A arranged in the curved section 72 is arranged on the outer side of the curved section 72 between the first travel track 81 and the second travel track 82, the moving speed of the central part of the transport vehicle 1 decreases during the period when the posture of the transport vehicle 1 changes from the second posture P2 to the third posture P3, and the moving speed of the central part of the transport vehicle 1 increases during the period when the posture of the transport vehicle 1 changes from the sixth posture P6 to the seventh posture P7.

[0055] like Figure 4As shown, if the length of the curved section 72 of the central portion 70a of the path width direction Y of the travel path 70 along the travel path 70 is set to the first length D1, and the length of the object rail 80A along the travel path 70 is set to the second length D2, then the ratio of the second length D2 to the first length D1 (i.e., the ratio with the first length D1 as the denominator and the second length D2 as the numerator, in other words, the value obtained by dividing the second length D2 by the first length D1) is the same as or substantially the same as the ratio of the moving speed of the first object wheel 31A to the moving speed of the central portion of the transport vehicle 1 relative to the curved section 72. In view of this, the control unit 60 of the present embodiment is configured to change the rotational speed of the first wheel 21 and the second wheel 22 in the curved section 72 relative to the rotational speed of the first wheel 21 and the second wheel 22 in the straight section 71, corresponding to the ratio of the second length D2 to the first length D1. Thus, as Figures 11 to 13 As shown in the calculation results of , the speed change of the central portion of the transport vehicle 1 when passing through the boundary B is suppressed to a small value, and the vibration that may occur in the transport vehicle 1 or the article 2 transported by the transport vehicle 1 can be suppressed to a small value. Figure 4 As shown in the illustrated example, in a curve section 72 having a constant curvature, the ratio of the second length D2 to the first length D1 can be determined based on the radius of curvature of the curve section 72 (e.g., the radius of curvature at the central portion 70a of the travel path 70) and the spacing between the first wheel 21 and the second wheel 22 in the width direction (the width direction of the first travel portion 11). Furthermore, in this embodiment, the spacing between the third wheel 23 and the fourth wheel 24 in the width direction (the width direction of the second travel portion 12) is equal to the spacing between the first wheel 21 and the second wheel 22 in the width direction (the width direction of the first travel portion 11).

[0056] Figures 11 to 13 In the embodiment, the following situation is assumed: the control unit 60 sets the rotational speed of the first wheel 21 and the second wheel 22 in the curved section 72 when the transport vehicle 1 moves at a set speed to a speed obtained by multiplying the rotational speed of the first wheel 21 and the second wheel 22 when the transport vehicle 1 moves at the set speed in the straight section 71 by the value obtained by dividing the second length D2 by the first length D1. Specifically, the rotational speed of the first wheel 21 and the second wheel 22 in the straight section 71 is set to a rotational speed (hereinafter referred to as the "reference rotational speed") at which the moving speed of the central portion of the transport vehicle 1 is the second speed V2. On the other hand, the rotational speed of the first wheel 21 and the second wheel 22 in the curved section 72 is set to a rotational speed obtained by multiplying the value obtained by dividing the second length D2 by the first length D1 by the reference rotational speed. Here, the second speed V2 is set so that the speed obtained by multiplying the second speed V2 by the value obtained by dividing the second length D2 by the first length D1 is the first speed V1. Therefore, as Figure 12As shown, the moving speed of the first target wheel 31A in the curve section 72 (here, the period during which the posture of the transport vehicle 1 changes from the third posture P3 to the sixth posture P6) is the first speed V1. Here, assuming that the value of the second length D2 divided by the first length D1 is "0.75", the relationship V1 = V2 × 0.75 holds.

[0057] By setting the rotation speeds of the first wheel 21 and the second wheel 22 in the curve section 72 as described above, Figure 13 As shown, the moving speed of the center portion of the guided vehicle 1 in the curved section 72 can be made close to the moving speed of the center portion of the guided vehicle 1 in the straight section 71 (here, the second speed V2). As a result, the speed change of the center portion of the guided vehicle 1 when passing through the boundary B can be suppressed to a minimum. In this way, the moving speed of the center portion of the guided vehicle 1 in the curved section 72 can be made close to the moving speed of the center portion of the guided vehicle 1 in the straight section 71 (here, the second speed V2). As a result, when the guided vehicle 1 sequentially travels through the straight section 71, the curved section 72, and another straight section 71, the moving speed in the curved section 72 can be prevented from becoming excessively high, while the moving speed in the straight section 71 can be maintained high. As a result, the time required for the guided vehicle 1 to travel along the travel path 70 can be shortened.

[0058] Here, the following example is described: in order to vary the rotational speed of the first and second wheels 21, 22 in the curved section 72 (hereinafter referred to as the "curved section rotational speed") relative to the rotational speed of the first and second wheels 21, 22 in the straight section 71 (hereinafter referred to as the "straight section rotational speed") in accordance with the ratio of the second length D2 to the first length D1, the curved section rotational speed is set to a value obtained by dividing the second length D2 by the first length D1 (hereinafter referred to as the "division value") by the straight section rotational speed. However, the configuration is not limited to this. The curved section rotational speed may also be set to a value corresponding to the division value (but different from the division value) by the straight section rotational speed, thereby varying the curved section rotational speed relative to the straight section rotational speed in accordance with the ratio of the second length D2 to the first length D1. The value corresponding to the division value may be, for example, a value obtained by multiplying the division value by a correction coefficient. This correction coefficient may be based on, for example, a dimension that affects the travel characteristics of the transport vehicle 1 (eg, the distance between the first axis A1 and the second axis A2 when viewed in the vehicle body vertical direction H).

[0059] As described above, the control unit 60 is configured to make the moving speed of the center portion of the guided vehicle 1 in the curved section 72 close to the moving speed of the center portion of the guided vehicle 1 in the straight section 71 ( Figure 13In the example shown, the second speed V2 is used to change the rotation speed in the curve section relative to the rotation speed in the straight section. Figure 13 In the example shown, the control unit 60 may be configured to change the curved section rotational speed relative to the linear section rotational speed so that the moving speed of the center portion of the transport vehicle 1 in the curved section 72 matches the moving speed of the center portion of the transport vehicle 1 in the linear section 71 .

[0060] In order to make the speed change of the center portion of the transport vehicle 1 smooth when the transport vehicle 1 passes through the boundary B, in this embodiment, the control unit 60 is configured to start changing the rotation speed of the first wheel 21 and the second wheel 22 in accordance with the timing when the first traveling portion 11 enters the curved section 72 from the straight section 71 and the timing when the first traveling portion 11 enters the straight section 71 from the curved section 72. Figure 7 As shown, in this embodiment, when the first traveling section 11 enters the curved section 72 from the straight section 71, the posture of the transport vehicle 1 is the second posture P2, and when the first traveling section 11 enters the straight section 71 from the curved section 72, the posture of the transport vehicle 1 is the sixth posture P6. Therefore, when the posture of the transport vehicle 1 changes to the second posture P2, the control unit 60 begins to change the rotational speed of the first wheels 21 and the second wheels 22 from the straight section rotational speed to the curved section rotational speed, and when the posture of the transport vehicle 1 changes to the sixth posture P6, the control unit 60 begins to change the rotational speed of the first wheels 21 and the second wheels 22 from the curved section rotational speed to the straight section rotational speed. In the present embodiment, the control unit 60 changes the rotational speeds of the first wheel 21 and the second wheel 22 from the straight section rotational speed to the curved section rotational speed so that the rotational speeds of the first wheel 21 and the second wheel 22 reach the curved section rotational speed when the posture of the transport vehicle 1 changes to the third posture P3, and changes the rotational speeds of the first wheel 21 and the second wheel 22 from the curved section rotational speed to the straight section rotational speed so that the rotational speeds of the first wheel 21 and the second wheel 22 reach the straight section rotational speed when the posture of the transport vehicle 1 changes to the seventh posture P7.

[0061] The control unit 60 changes the rotation speed of the first wheel 21 and the second wheel 22 as described above. Figure 12In the example shown, the moving speed of the first target wheel 31A, which is determined corresponding to the rotational speed of the first target wheel 31A, is maintained at the second speed V2 while the posture of the transport vehicle 1 is in the second posture P2, and is changed from the second speed V2 to the first speed V1 while the posture of the transport vehicle 1 is changing from the second posture P2 to the third posture P3. The first speed V1 is maintained while the posture of the transport vehicle 1 is changing from the third posture P3 to the sixth posture P6, and is changed from the first speed V1 to the second speed V2 while the posture of the transport vehicle 1 is changing from the sixth posture P6 to the seventh posture P7.

[0062] As described above, in this embodiment, the control unit 60 starts changing the rotational speeds of the first and second wheels 21, 22 from the straight-line rotational speeds to the curved-line rotational speeds when the transport vehicle 1 reaches the second posture P2, and starts changing the rotational speeds of the first and second wheels 21, 22 from the curved-line rotational speeds to the straight-line rotational speeds when the transport vehicle 1 reaches the sixth posture P6. In this embodiment, the control unit 60 is configured to determine the timing of the transport vehicle 1 reaching the second and sixth postures P2, P6, as follows.

[0063] In this embodiment, if Figure 5 As shown, at the boundary B with the travel path 70 (refer to Figure 4 ) The detected object 3 is set at the corresponding position, such as Figure 3 As shown, the transport vehicle 1 includes a detection device 14 for detecting the detection object 3. For example, a reflective tape that reflects light can be used as the detection object 3, and a reflective optical sensor can be used as the detection device 14. Figure 2 In the illustrated example, the detection object 3 is placed on the lower surface of the target rail 80A, and the detection device 14 is placed on the upper portion of the main body 13 . Figure 2 In the illustrated example, the detection device 14 used when the first travel rail 81 is the target rail 80A and the detection device 14 used when the second travel rail 82 is the target rail 80A are provided separately.

[0064] In this embodiment, the object 3 to be detected, which is located at a position corresponding to the first boundary B1, is located at a position where it is detected by the detection device 14 when the transport vehicle 1 is in the second posture P2. Furthermore, the object 3 to be detected, which is located at a position corresponding to the second boundary B2, is located at a position where it is detected by the detection device 14 when the transport vehicle 1 is in the sixth posture P6. Alternatively, the object 3 to be detected may be located upstream of the travel path 70 by a distance corresponding to the control delay, by X2, relative to the position described herein.

[0065] In addition, in this embodiment, if Figure 5 As shown, an information holding body 4 holding address information indicating the position is provided at a position X2 upstream of the travel path 70 relative to the boundary B. Figure 3 As shown, the transport vehicle 1 includes a reader 15 for reading address information held on the information holder 4, and a measuring device 16 for measuring the travel distance of the first traveling portion 11. The information holder 4 holds address information (information indicating the position along the travel path 70) indicating the location where the information holder 4 is located. For example, a one-dimensional code or a two-dimensional code can be used as the information holder 4, and a one-dimensional code reader or a two-dimensional code reader can be used as the reader 15. Figure 5 In the example shown, the information holding member 4 is provided in the linear section 71. The information holding member 4 is provided, for example, on the lower surface of the first travel rail 81 or the second travel rail 82. Furthermore, as the measuring device 16, for example, a rotary encoder can be used.

[0066] The control unit 60 derives the estimated current position of the first traveling unit 11, or the estimated current position, based on the address information read by the reader 15 and the travel distance of the first traveling unit 11 measured by the measuring device 16 (specifically, the travel distance from the time the reader 15 reads the address information). The estimated current position is the estimated current position of the first traveling unit 11 in the longitudinal direction X of the path. The estimated current position is, for example, the position of one of the first and second wheels 21 and 22, which is the first target wheel 31A, or the position of one of the first and second auxiliary wheels 51 and 52, which is the first target auxiliary wheel.

[0067] Furthermore, when the first condition or the second condition is satisfied, the control unit 60 determines that the first traveling unit 11 has reached the boundary B and starts changing the rotational speed of the first wheel 21 and the second wheel 22. The area extending from the boundary B to both sides along the traveling path 70 (the area in the longitudinal direction X of the path) is defined as the boundary area C (refer to FIG. Figure 4 ), the first condition is that the estimated current position of the first traveling unit 11 is within the boundary area C and the detection device 14 detects the detected object 3, and the second condition is that the estimated current position of the first traveling unit 11 enters the boundary area C, the detected object 3 is not detected by the detection device 14, and the estimated current position reaches the end of the downstream side X1 of the travel path 70 of the boundary area C. Alternatively, the first condition can be simply set to that the estimated current position of the first traveling unit 11 is within the boundary area C (in other words, the estimated current position of the first traveling unit 11 enters the boundary area C). Alternatively, the first condition can be simply set to that the detected object 3 is detected by the detection device 14.

[0068] In this embodiment, two boundary regions C are defined: a first boundary region C1 extending from a first boundary B1 to both sides along the travel path 70, and a second boundary region C2 extending from a second boundary B2 to both sides along the travel path 70. The control unit 60 uses the first boundary region C1 as the boundary region C to determine whether the first and second conditions described above are satisfied. If either the first or second condition is satisfied, the control unit 60 determines that the first traveling unit 11 has reached the first boundary B1 (in other words, determines that the posture of the transport vehicle 1 is the second posture P2), and begins to change the rotational speed of the first and second wheels 21, 22 from the linear interval rotational speed to the curved interval rotational speed. In addition, the control unit 60 uses the second boundary area C2 as the boundary area C to determine whether the above-mentioned first condition and second condition are met. When the first condition or the second condition is met, it is determined that the first traveling portion 11 has reached the second boundary B2 (in other words, it is determined that the posture of the transport vehicle 1 is the sixth posture P6), and the rotation speed of the first wheel 21 and the second wheel 22 begins to change from the curved interval rotation speed to the straight interval rotation speed.

[0069] In this embodiment, the control unit 60 is configured to Figure 14 and Figure 15 The speed weight function (speed weight table) prepared in advance as shown in the example sets the curve section rotation speed based on the straight section rotation speed. The speed weight function represents the speed weight (the ratio of the curve section rotation speed to the straight section rotation speed) at each position in the curve section 72. Figure 14 and Figure 15 The horizontal axis represents the distance along the travel path 70 from the reference position (in other words, the position in the longitudinal direction X of the path). By multiplying the straight section rotation speed by the speed weight function, the curve section rotation speed at each position of the curve section 72 can be derived. The speed weight function can be prepared by calculation based on parameters related to the shape of the curve section 72 and parameters related to the structure of the transport vehicle 1. The parameters related to the shape of the curve section 72 include, for example, the radius of curvature, and the parameters related to the structure of the transport vehicle 1 include, for example, the interval between the first wheel 21 and the second wheel 22 in the width direction (the width direction of the first traveling portion 11), and the interval between the first axis A1 and the second axis A2 as viewed in the direction of the vehicle body up and down direction H. In addition, it is also possible to configure the control unit 60 to calculate the curve section rotation speed each time for setting without using such a speed weight function.

[0070] Figure 14 、 Figure 15 The speed-weight function shown is Figure 12 The speed weight function showing the case where the moving speed of the first target wheel 31A is changed assumes that the value of the second length D2 divided by the first length D1 is "0.75". Figure 14 、 Figure 15 In the speed weight function shown, the speed weight between the position where the transport vehicle 1 is in the third posture P3 and the position where the transport vehicle 1 is in the sixth posture P6 is 75%. Furthermore, the speed weight remains at 100% until the transport vehicle 1 reaches the second posture P2. It changes from 100% to 75% during the period from the second posture P2 to the third posture P3. It remains at 75% during the period from the third posture P3 to the sixth posture P6. It changes from 75% to 100% during the period from the sixth posture P6 to the seventh posture P7.

[0071] Figure 14 In the figure, the rate of change of speed weight (the rate of change relative to distance) is expressed together with the speed weight. Figure 14 In the example shown, the speed weight is changed while changing the rate of change of the speed weight between the position where the transport vehicle 1 is in the second posture P2 and the position where the transport vehicle 1 is in the third posture P3, and between the position where the transport vehicle 1 is in the sixth posture P6 and the position where the transport vehicle 1 is in the seventh posture P7. Although not shown in the figure, Figure 14 In the example, the speed weight is changed in such a way that the rate of change of the speed weight (i.e., the second-order differential value of the speed weight) is constant. Figure 14 In the case of the speed-weight function shown in FIG. 1 , when the control unit 60 changes the rotational speeds of the first wheel 21 and the second wheel 22 between the linear section rotational speed of the rotational speed in the linear section 71 and the curved section rotational speed of the rotational speed in the curved section 72, the rotational speeds of the first wheel 21 and the second wheel 22 change so that the second-order differential value of the rotational speed remains constant (but remains constant at a value other than zero). The second-order differential value of the rotational speed here refers to the second-order differential value with respect to distance or the second-order differential value with respect to time.

[0072] also, Figure 15 In the example where the speed weight is expressed together with the speed weight, the rate of change of the speed weight (the rate of change relative to the distance) is expressed, Figure 15 In the example shown, the speed weight is changed so that the rate of change of the speed weight is constant between the position where the transport vehicle 1 is in the second posture P2 and the position where the transport vehicle 1 is in the third posture P3, and between the position where the transport vehicle 1 is in the sixth posture P6 and the position where the transport vehicle 1 is in the seventh posture P7. Figure 15In the case of the speed-weight function shown in FIG. 1 , when the control unit 60 changes the rotational speed of the first wheel 21 and the second wheel 22 between the linear section rotational speed of the rotational speed in the linear section 71 and the curved section rotational speed of the rotational speed in the curved section 72, the rotational speed of the first wheel 21 and the second wheel 22 changes so that the first-order differential value of the rotational speed remains constant. The first-order differential value of the rotational speed here is the first-order differential value with respect to distance or the first-order differential value with respect to time.

[0073] Figure 16 Lieutenant General Figure 14 The time variation of the moving acceleration of the center portion of the transport vehicle 1 in the case of the speed-weight function shown in FIG is represented by a solid line. Figure 15 The time variation of the moving acceleration of the center portion of the transport vehicle 1 in the case of the speed-weight function shown in FIG is represented by a dotted line. Figure 16 It can be seen that using Figure 14 The speed-weight function shown is used with Figure 15 Compared with the case of the speed-weight function shown in FIG. 1 , it is easy to change the rotational speed of the first wheel 21 and the second wheel 22 in a manner that the movement acceleration of the central portion of the transport vehicle 1 changes smoothly. Figure 15 In the case of the speed-weight function shown in Figure 10 Compared with the comparative example shown, the change in the moving acceleration of the central portion of the transport vehicle 1 can be suppressed to be small.

[0074] [Other Implementation Methods]

[0075] Next, other embodiments of the article transport equipment will be described.

[0076] (1) In the above embodiment, an example is described in which the control unit 60 is configured to determine that the first traveling unit 11 has reached the boundary B when the first condition or the second condition is satisfied, and to start changing the rotational speeds of the first wheel 21 and the second wheel 22. However, the present application is not limited to such a configuration. For example, the control unit 60 may be configured to determine that the first traveling unit 11 has reached the boundary B and to start changing the rotational speeds of the first wheel 21 and the second wheel 22 only when the first condition is satisfied.

[0077] In addition, the control unit 60 may be configured to determine whether the first traveling unit 11 has reached the boundary B without using either the first condition or the second condition. Figure 11 and Figure 12As shown, when the guided vehicle 1 enters the curved section 72 from the straight section 71, after the position of the guided vehicle 1 changes to the zeroth position P0, the moving speed of the first target wheel 31A is maintained at the second speed V2, while the moving speed of the second target wheel 32A decreases from the second speed V2. Furthermore, when the guided vehicle 1 enters the straight section 71 from the curved section 72, after the position of the guided vehicle 1 changes to the fourth position P4, the moving speed of the first target wheel 31A is maintained at the first speed V1, while the moving speed of the second target wheel 32A increases from the first speed V1. In view of this, for example, the control unit 60 can be configured such that, after detecting a change in the rotational speed of the second target wheel 32A relative to the rotational speed of the first target wheel 31A, the control unit 60 determines that the first travel unit 11 has reached the boundary B when the first travel unit 11 has traveled a distance corresponding to the distance between the first and second target wheels 31A, 32A, in the vehicle body front-rear direction L, and initiates a change in the rotational speeds of the first and second wheels 21, 22. The change in the rotational speed of the second object wheel 32A relative to the rotational speed of the first object wheel 31A can be detected at a time before the start of the rotational speed change of the first wheel 21 and the second wheel 22. Therefore, in this scheme, even if there is a control delay, it is easy to start the rotational speed change of the first wheel 21 and the second wheel 22 at the desired timing.

[0078] Specifically, the control unit 60 can be configured as follows. That is, the control unit 60 detects a change in the rotation speed of the second target wheel 32A relative to the rotation speed of the first target wheel 31A (the target track 80A descends at the inner curve section 72 and the target track 80A rises at the outer curve section 72), and then, when the first traveling portion 11 travels a distance ( L ) corresponding to the distance between the first target wheel 31A and the second target wheel 32A in the vehicle body front-rear direction L, the control unit 60 controls the first traveling portion 11 to travel a distance ( L ) corresponding to the distance between the first target wheel 31A and the second target wheel 32A in the vehicle body front-rear direction L. Figure 7 In the example shown, the first traveling section 11 travels a distance corresponding to the distance in the vehicle body front-rear direction L between the first and second wheels 21, 22 (the distance traveled by the first traveling section 11 during the period when the posture of the transport vehicle 1 changes from the 0th posture P0 to the 2nd posture P2). The controller 60 determines that the first traveling section 11 reaches the first boundary B1 and starts changing the rotational speed of the first and second wheels 21, 22 from the linear interval rotational speed to the curved interval rotational speed. Furthermore, the controller 60 detects a change in the rotational speed of the second target wheel 32A relative to the rotational speed of the first target wheel 31A (the target track 80A rises in the curved interval 72 on the inner circumference and the target track 80A falls in the curved interval 72 on the outer circumference). Figure 7In the example shown, at the moment when the posture of the transport vehicle 1 changes from the 4th posture P4 to the 6th posture P6 (the distance traveled by the first traveling portion 11), it is determined that the first traveling portion 11 reaches the second boundary B2 and begins to change from the curve interval rotation speed of the rotation speed of the first wheel 21 and the second wheel 22 to the straight interval rotation speed.

[0079] (2) In the above embodiment, the second traveling portion 12 is arranged on the front side L1 relative to the first traveling portion 11. However, the present application is not limited to such a configuration, and the second traveling portion 12 may be arranged on the rear side L2 relative to the first traveling portion 11.

[0080] (3) In the above embodiment, the transport vehicle 1 is described as including the second travel portion 12. However, the present application is not limited to such a configuration, and the transport vehicle 1 may be configured without the second travel portion 12. In this case, the first travel portion 11 may be connected to the main body 13 so as to be non-rotatable about an axis extending along the vehicle body vertical direction H.

[0081] (4) In addition, the structures disclosed in each of the above embodiments can also be combined with the structures disclosed in other embodiments (including combinations of the embodiments described as other embodiments) as long as no contradiction arises. With respect to other schemes, the embodiments disclosed in this specification are merely illustrative in all aspects. Therefore, various changes can be appropriately made within the scope of the purpose of this application.

[0082] [Overview of the above embodiment]

[0083] Hereinafter, the outline of the article transport facility described above will be described.

[0084] The article handling equipment comprises a travel track, a transport vehicle, and a control unit, wherein the travel track is arranged along a travel path, the transport vehicle travels along the travel track to transport articles, and the control unit controls the travel operation of the travel unit of the transport vehicle, the article handling equipment being characterized in that the travel path includes a straight section formed as a straight line when viewed from above and a curved section formed as a curve when viewed from above, in the straight section, two travel tracks, namely a first travel track and a second travel track, are arranged on both sides of a central portion in a width direction of the travel path, one of the first travel track and the second travel track is set as a target track, and the other is set as a non-target track, in the curved section, at least the target track of the target track and the non-target track is arranged, and a guide rail other than the target track and the non-target track is arranged along the travel path, and the travel unit includes a first wheel rolling on a travel surface of the first travel track, and a second wheel rolling on a travel surface of the second travel track. a wheel, a driving unit for rotating the first wheel and the second wheel at the same speed, and a guide wheel rolling on a guide surface of the guide rail; when the target rail is the first travel rail, the first wheel is a target wheel; when the target rail is the second travel rail, the second wheel is a target wheel; and one of the first and second wheels that is not the target wheel is a non-target wheel; the travel unit travels in the curved section in a posture in which the target wheel is in contact with the target rail, the guide wheel is in contact with the guide rail, and the non-target wheel is not in contact with the non-target rail; the control unit changes the rotational speed of the first and second wheels in the curved section relative to the rotational speed of the first and second wheels in the straight section based on a ratio of a first length, which is a length of the curved section along the travel path, to a second length, which is a length of the target rail along the travel path, relative to a center portion in the width direction of the travel path.

[0085] According to this solution, the transport unit maintains a posture when traveling in a curved section, with the target wheel in contact with the target rail, the guide wheel in contact with the guide rail, and the non-target wheel not in contact with the non-target rail. Therefore, in a curved section where the lengths of the target wheel's and non-target wheel's moving paths differ, the target wheel and non-target wheel can rotate at the same speed, allowing the transport vehicle to travel appropriately. In other words, according to this solution, the transport vehicle can travel appropriately in a curved section by driving both its left and right wheels at the same speed.

[0086] Furthermore, in this embodiment, the rotational speeds of the first and second wheels in the curved section vary in accordance with the ratio of the second length to the first length relative to the rotational speeds of the first and second wheels in the straight section. Here, the ratio of the second length to the first length is the same as or substantially the same as the ratio of the moving speed of the target wheel relative to the moving speed of the center portion of the transport vehicle (the center portion in the width direction, the same applies hereinafter). Therefore, by setting the rotational speeds of the first and second wheels in the curved section as described above, the moving speed of the center portion of the transport vehicle in the curved section can be made close to the moving speed of the center portion of the transport vehicle in the straight section. As a result, the speed change of the center portion of the transport vehicle when passing through the boundary between the straight section and the curved section can be suppressed to a small value, and the vibration that occurs in the transport vehicle and the items being transported by the transport vehicle can be suppressed to a small value.

[0087] Furthermore, unlike this embodiment, when the rotational speeds of the first and second wheels in the curved section are not changed relative to the rotational speeds of the first and second wheels in the straight section, the moving speed of the central portion of the transport vehicle in the curved section, where the target track is on the inner circumference, becomes higher than the moving speed of the central portion of the transport vehicle in the straight section. Therefore, in order to suppress the moving speed of the central portion of the transport vehicle in the curved section to below the maximum permissible speed, it is necessary to suppress the moving speed of the central portion of the transport vehicle in the straight section to a lower level. In contrast, according to this embodiment, the moving speed of the central portion of the transport vehicle in the curved section can be brought closer to the moving speed of the central portion of the transport vehicle in the straight section, thus reducing such a need and shortening the time required for the transport vehicle to travel along a path that includes both straight and curved sections.

[0088] Here, preferably, the control unit sets the rotational speed of the first wheel and the second wheel in the curved section when traveling at a set speed to the following speed: the rotational speed of the first wheel and the second wheel when traveling in the straight section at the set speed multiplied by a value obtained by dividing the second length by the first length.

[0089] According to this embodiment, the moving speed of the center portion of the transport vehicle in a curved section can be made equal to or substantially equal to the moving speed of the center portion of the transport vehicle in a straight section. This allows the speed change of the center portion of the transport vehicle when passing the boundary between a straight section and a curved section to be minimized.

[0090] Furthermore, preferably, the control unit starts changing the rotational speeds of the first wheel and the second wheel in conjunction with the timing when the traveling unit enters the curved section from the straight section and the timing when the traveling unit enters the straight section from the curved section.

[0091] According to this solution, the rotational speed of the first and second wheels can be changed in conjunction with the timing when the difference between the moving speed of the central portion of the transport vehicle and the moving speed of the target wheel begins to change. Thus, the rotational speed of the first and second wheels can be changed in conjunction with the change in the difference between the moving speed of the central portion of the transport vehicle and the moving speed of the target wheel, making it possible to smoothly change the speed of the central portion of the transport vehicle when passing through the boundary between a straight section and a curved section.

[0092] In addition, preferably, when the control unit changes the rotational speed of the first wheel and the second wheel between the rotational speed in the straight line interval and the rotational speed in the curved interval, the rotational speed of the first wheel and the second wheel changes in such a manner that the first-order differential value of the rotational speed is constant.

[0093] According to this scheme, the rate of change of the rotational speeds of the first wheel and the second wheel is kept constant when the rotational speeds of the first wheel and the second wheel change, so that the control of changing the rotational speeds of the first wheel and the second wheel between the rotational speeds in the straight section and the rotational speeds in the curved section can be simplified.

[0094] In addition, preferably, when the control unit changes the rotational speed of the first wheel and the second wheel between the rotational speed in the straight line interval and the rotational speed in the curved line interval, the rotational speed of the first wheel and the second wheel changes in a manner such that the second-order differential value of the rotational speed remains constant.

[0095] According to this solution, compared to a case where the rotational speeds of the first and second wheels are changed so that the first-order differential value of the rotational speeds remains constant, it is easier to change the rotational speeds of the first and second wheels so that the change in the moving acceleration of the central portion of the transport vehicle is smooth. This makes it easier to minimize vibrations in the transport vehicle and in items being transported by the transport vehicle.

[0096] In addition, preferably, a detected object is provided at a position of the aforementioned travel path corresponding to the boundary between the aforementioned straight section and the aforementioned curved section, and an information holding body holding address information indicating the position is provided at a position on the upstream side of the aforementioned travel path relative to the aforementioned boundary, the aforementioned transport vehicle is provided with a detection device for detecting the aforementioned detected object, a reading device for reading the aforementioned address information held on the aforementioned information holding body, and a measuring device for measuring the travel distance of the aforementioned travel portion, and an area extending from the aforementioned boundary to both sides along the aforementioned travel path is set as a boundary area, and the aforementioned control unit determines the distance of the aforementioned travel portion based on the aforementioned address information read by the aforementioned reading device and the aforementioned measuring device. The device measures the above-mentioned travel distance, and derives the current estimated position of the above-mentioned traveling portion, i.e., the estimated current position. When the first condition or the second condition is met, it is determined that the above-mentioned traveling portion has reached the above-mentioned boundary and the rotational speed of the above-mentioned first wheel and the above-mentioned second wheel starts to change. The above-mentioned first condition is that the above-mentioned estimated current position is a position within the above-mentioned boundary area, and the above-mentioned detected object is detected with the help of the above-mentioned detection device. The above-mentioned second condition is that after the above-mentioned estimated current position enters the above-mentioned boundary area, the above-mentioned estimated current position reaches the end of the downstream side of the above-mentioned travel path of the above-mentioned boundary area without the above-mentioned detected object being detected by the above-mentioned detection device.

[0097] According to this solution, the rotational speed change of the first and second wheels can be appropriately initiated based on the first and second conditions. Specifically, the condition for initiating the rotational speed change of the first and second wheels, i.e., the first condition, includes, in addition to the detection of the detected object by the detection device, the estimation of the current position as a position within the boundary area. Therefore, the detection of the detected object by the detection device in a state where the current position is estimated not to be a position within the boundary area can be determined as a false detection and the rotational speed change of the first and second wheels will not be initiated. Moreover, the detection of the detected object by the detection device in a state where the current position is estimated to be a position within the boundary area can be determined as a correct detection and the rotational speed change of the first and second wheels can be initiated. In addition, the rotational speed change of the first and second wheels can be initiated even if the second condition is established when the first condition is not established. Therefore, even if the traveling portion reaches the boundary between the straight section and the curved section, the rotational speed change of the first and second wheels can be initiated when the detection device cannot detect the detected object due to peeling, contamination, etc. of the detected object.

[0098] In addition, preferably, the aforementioned travel portion is set as the first travel portion, the aforementioned transport vehicle has a second travel portion arranged on the front side along the front-rear direction of the aforementioned travel path relative to the aforementioned first travel portion, and a main body portion connected to the aforementioned first travel portion and the aforementioned second travel portion, the aforementioned first travel portion is rotatably connected to the aforementioned main body portion around a first axis along the vertical direction, the aforementioned second travel portion is rotatably connected to the aforementioned main body portion around a second axis along the vertical direction, the aforementioned guide wheel is set as the first guide wheel, and the aforementioned The second traveling portion includes a third wheel rolling on the traveling surface of the first traveling track, a fourth wheel rolling on the traveling surface of the second traveling track, and a second guide wheel rolling on the guide surface of the guide track. The control portion controls the rotational speeds of the first wheel and the second wheel in a manner consistent with the target rotational speed, and causes the second traveling portion to travel in a manner slave to the travel of the first traveling portion, and sets the target wheel as the first target wheel and the non-target wheel as the first non-target wheel. and a second non-target wheel. The second wheel is a wheel having a rotational speed of at least one wheel and a second non-target wheel having a rotational speed of at least one ...

[0099] In this embodiment, the control unit controls the rotational speeds of the first and second wheels to match the target rotational speed, and when the second traveling unit moves in a manner slaved to the movement of the first traveling unit, the rotational speed of the second target wheel is changed from the target rotational speed (i.e., the rotational speed of the first target wheel) before and after the second traveling unit passes the boundary between the straight section and the curved section, while the rotational speed of the first target wheel is maintained at the target rotational speed. According to this embodiment, based on the detection result of the change in the rotational speed of the second target wheel relative to the rotational speed of the first target wheel, it is determined whether the first traveling unit has reached the boundary between the straight section and the curved section, and the rotational speed change of the first and second wheels can be initiated.

[0100] The article transporting equipment of the present application only needs to have at least one of the above-mentioned effects.

[0101] Description of Reference Numerals

[0102] 1: Truck

[0103] 2: Items

[0104] 3: Detected object

[0105] 4: Information retention body

[0106] 11: 1st marching section (marching section)

[0107] 12: Second Marching Unit

[0108] 13: Main body

[0109] 14: Detection device

[0110] 15: Reading device

[0111] 16: Measuring device

[0112] 21: Wheel 1

[0113] 22: Wheel 2

[0114] 23: Wheel 3

[0115] 24: 4th wheel

[0116] 31A: First target wheel (target wheel)

[0117] 31B: First non-target wheel (non-target wheel)

[0118] 32A: Second target wheel

[0119] 32B: Second non-target wheel

[0120] 41: First guide wheel (guide wheel)

[0121] 42: Second guide wheel

[0122] 60: Control Department

[0123] 70: Travel Path

[0124] 70a: Central

[0125] 71: Straight line interval

[0126] 72: Curve interval

[0127] 80: Track

[0128] 80A: Object track

[0129] 80B: Non-target track

[0130] 81: Track 1

[0131] 82: Second track

[0132] 83: Guide Track

[0133] 100: Goods handling equipment

[0134] A1: Axis 1

[0135] A2: Second Axis

[0136] B: Boundary

[0137] C: Boundary area

[0138] D1: 1st length

[0139] D2: 2nd length

[0140] H: vehicle body up and down direction (up and down direction)

[0141] L: Front-to-back direction of the vehicle body (front-to-back direction)

[0142] L1: front side

[0143] M1: 1st drive unit (drive unit)

[0144] X1: Downstream side

[0145] X2: Upstream side

[0146] Y: Path width direction (width direction).

Claims

1. An article handling device comprising a travel track, a transport vehicle, and a control unit. The aforementioned travel track is arranged along the travel path, The transport vehicle moves along the travel track to transport items. The control unit controls the travel operation of the travel unit of the transport vehicle. The aforementioned article handling equipment is characterized in that: The aforementioned travel path includes a straight section that is formed in a straight line shape when viewed from above and a curved section that is formed in a curved shape when viewed from above. In the straight section, two travel rails, namely a first travel rail and a second travel rail, are arranged on both sides of a center portion in a width direction of the travel path, one of the first travel rail and the second travel rail is set as a target rail, and the other is set as a non-target rail. In the curved section, at least the target rail of the target rail and the non-target rail is arranged, and guide rails other than the target rail and the non-target rail are arranged along the travel path. The travel portion includes a first wheel rolling on the travel surface of the first travel rail, a second wheel rolling on the travel surface of the second travel rail, a driving portion for rotating the first wheel and the second wheel at the same speed, and a guide wheel rolling on the guide surface of the guide rail. When the target track is the first travel track, the first wheel is set as the target wheel and the second wheel is set as the non-target wheel; when the target track is the second travel track, the second wheel is set as the target wheel and the first wheel is set as the non-target wheel. The traveling unit travels in the curved section with the target wheel in contact with the target rail, the guide wheel in contact with the guide rail, and the non-target wheel not in contact with the non-target rail. The control unit changes the rotational speed of the first wheel and the second wheel in the curved section relative to the rotational speed of the first wheel and the second wheel in the straight section based on the ratio of the second length to the first length, wherein the first length is the length of the curved section in the central part of the width direction of the travel path along the travel path, and the second length is the length of the object track along the travel path.

2. The article handling equipment according to claim 1, wherein: The control unit sets the rotational speeds of the first wheel and the second wheel in the curved section when traveling at a set speed to the following speeds: the rotational speeds of the first wheel and the second wheel when traveling in the straight section at the set speed multiplied by the value obtained by dividing the second length by the first length.

3. The article handling equipment according to claim 1 or 2, characterized in that: The control unit starts changing the rotational speeds of the first wheel and the second wheel in accordance with a timing when the traveling unit enters the curved section from the straight section and a timing when the traveling unit enters the straight section from the curved section.

4. The article handling equipment according to claim 1 or 2, characterized in that: When the control unit changes the rotational speed of the first wheel and the second wheel between the rotational speed in the straight section and the rotational speed in the curved section, the rotational speed of the first wheel and the second wheel changes in such a manner that the first-order differential value of the rotational speed is constant.

5. The article handling equipment according to claim 1 or 2, characterized in that: When the control unit changes the rotational speed of the first wheel and the second wheel between the rotational speed in the straight section and the rotational speed in the curved section, the rotational speed of the first wheel and the second wheel changes in such a manner that the second-order differential value of the rotational speed is constant.

6. The article handling equipment according to claim 1 or 2, characterized in that: A detection object is provided at a position on the travel path corresponding to a boundary between the straight section and the curved section, and an information holding body is provided at a position on the upstream side of the travel path relative to the boundary, holding address information indicating the position. The transport vehicle includes a detection device for detecting the detected object, a reading device for reading the address information held in the information holding body, and a measuring device for measuring the travel distance of the traveling portion. The area extending from the boundary to both sides along the path is defined as the boundary area. The control unit derives an estimated current position of the traveling unit, i.e., an estimated current position, based on the address information read by the reading device and the travel distance measured by the measuring device. When the first condition or the second condition is satisfied, the control unit determines that the traveling unit has reached the boundary and starts changing the rotational speeds of the first and second wheels. The first condition is that the estimated current position is within the boundary area and the detected object is detected by the detection device. The second condition is that, after the estimated current position enters the boundary area, the estimated current position reaches the downstream end of the travel path in the boundary area without the detection device detecting the detected object.

7. The article handling equipment according to claim 1 or 2, characterized in that: The travel portion is set as a first travel portion, the transport vehicle includes a second travel portion arranged on the front side of the first travel portion along the front-rear direction of the travel path, and a main body connected to the first travel portion and the second travel portion. The first traveling portion is rotatably connected to the main body portion around a first axis along the vertical direction. The second traveling portion is rotatably connected to the main body portion around a second axis along the vertical direction. The guide wheel is set as the first guide wheel, the second travel portion includes a third wheel rolling on the travel surface of the first travel rail, a fourth wheel rolling on the travel surface of the second travel rail, and a second guide wheel rolling on the guide surface of the guide rail. The control unit controls the rotational speeds of the first wheel and the second wheel to be consistent with the target rotational speed, and causes the second traveling unit to travel in a manner driven by the travel of the first traveling unit. The target wheel is set as the first target wheel and the non-target wheel is set as the first non-target wheel. Furthermore, when the first wheel is the first target wheel, the third wheel is set as the second target wheel, and the fourth wheel is set as the second non-target wheel. When the second wheel is the first target wheel, the fourth wheel is set as the second target wheel, and the third wheel is set as the second non-target wheel. The second traveling portion travels in the curved section in a posture in which the second target wheel is in contact with the target rail, the second guide wheel is in contact with the guide rail, and the second non-target wheel is not in contact with the non-target rail. After the control unit detects a change in the rotational speed of the second object wheel relative to the rotational speed of the first object wheel, at the moment when the first traveling unit travels a distance corresponding to the interval in the front-to-rear direction between the first object wheel and the second object wheel, it determines that the first traveling unit has reached the boundary between the straight section and the curved section of the traveling path, and starts to change the rotational speeds of the first wheel and the second wheel.

Images