Walking vehicle system

Abstract

This invention provides a vehicle system that, in a merging area including a merging point, stops vehicles traveling on other routes at a stopping point near the merging point until a vehicle traveling on one route passes through the merging area. The system calculates the time required for a first vehicle to pass through the merging area after the first vehicle and outside the merging area on the same route as the first vehicle, and ensures that a second vehicle, following the first vehicle and traveling on the same route outside the merging area, can enter the merging area within the required time, enters the merging area without decelerating to a speed below the limit required to stop at the stopping point.

Description

Walking vehicle system One aspect of the present invention relates to a vehicle system. A known vehicle system is characterized by a control (locking control) that stops vehicles traveling on other routes at a stop point near the merging point in a merging area that includes multiple travel routes, until a vehicle traveling on one route passes through the merging area (for example, see Japanese Patent Application Publication No. 2013-20423). [The problem the invention aims to solve] In the aforementioned vehicle system, considering the possibility of stopping the vehicle at a designated stopping point, the vehicle is sometimes slowed down to a speed below the limit required to stop at the stopping point before entering the merging area. However, in this case, the vehicle slows down even when there are no other vehicles in the merging area, potentially unnecessarily extending the travel time. Therefore, one objective of this invention is to provide a vehicle system capable of suppressing the extension of walking time. [Technical means to solve the problem] In one aspect of the present invention, a vehicle system controls vehicles traveling on other routes to stop at a stop point near the stop point in a convergence area comprising multiple convergence points, until a vehicle traveling on one route passes through the convergence area. The system calculates the required time, which is the time from the start of the convergence area until the first vehicle passes through the convergence point. If a second vehicle, following the first vehicle and traveling on the same route outside the convergence area, is able to enter the convergence area within the required time, the second vehicle is allowed to enter the convergence area without decelerating to a speed below the limit required to stop at the stop point. In this vehicle system, before the first vehicle traveling in the merging area passes through the merging area, other vehicles traveling on different routes (hereinafter referred to as "opposite vehicles") are prohibited from entering the merging point. Under this prohibition, if a second vehicle traveling on the same route as the first vehicle can enter the merging area (i.e., can enter the merging area within the required time), there is no concern about the second vehicle contacting the opposite vehicle at the merging point (the opposite vehicle entering the merging point). Therefore, it is not necessary to decelerate the second vehicle below the speed limit; for example, the second vehicle can enter the merging area at high speed. Thus, according to one aspect of the invention, the extension of travel time can be suppressed. One embodiment of the traveling vehicle system of the present invention may also include: an information output device disposed on the traveling vehicle for outputting information related to the required time to other traveling vehicles following the traveling vehicle; and an information input device disposed on the traveling vehicle for inputting information related to the required time from other traveling vehicles preceding the traveling vehicle. In this case, information related to the required time can be directly transmitted and received between the traveling vehicles. In one embodiment of the mobile vehicle system of the present invention, the information output device may be a display, and the information input device may be a camera or a light sensor. In this case, even in environments where wireless communication is difficult, information related to the required time can be directly transmitted and received in the mobile vehicle system. In one embodiment of the present invention, the traveling vehicle system can also decelerate the second traveling vehicle to below a limited speed if it cannot enter the merging area within the required time. This allows for the consideration of the possibility that an oncoming traveling vehicle might enter the merging point, thus stopping the second traveling vehicle at a stopping point and decelerating it to below the limited speed. In one embodiment of the present invention, the merging area corresponds to the guide line area, which has guide lines arranged around the merging point along the travel path. In this case, the guide line area can be used as the merging area to form the system. [Effects of the Invention] According to one aspect of the present invention, a vehicle system capable of suppressing the extension of walking time can be provided. Hereinafter, one embodiment will be described in detail with reference to the accompanying drawings. In the description of the drawings, the same or equivalent elements are labeled with the same symbols, and repeated descriptions are omitted. As shown in Figure 1, the mobile cart system 1 is a system that uses a mobile cart 6 capable of moving along a track 4 to transport items 10. Items 10 include, for example, containers such as FOUPs (Front Opening Unified Pods) for holding multiple semiconductor wafers, intermediate mask boxes for holding glass substrates, and general-purpose parts. Here, for example, the mobile cart system 1 in which the mobile cart 6 moves along a one-way track 4 laid on the ceiling of a factory will be described as an example. Furthermore, the terms "front" and "rear" will be used below to correspond to the forward and rearward directions of the mobile cart 6's movement, and the terms "up" and "down" will correspond to the upper and lower vertical directions. The traveling vehicle system 1 includes a track 4, multiple traveling vehicles 6, and a controller 60. As shown in Figures 2 and 3, the track 4 is laid, for example, near the ceiling above the operator's head. The track 4 is, for example, suspended from the ceiling. The track 4 is a predetermined path for the traveling vehicles 6 to move. The track 4 has a cylindrical guide rail body, which is composed of a pair of lower portions 40B, a pair of side portions 40C, 40C, and a top portion 40D. A guide plate 40G is fixed to the lower portion 40B (the lower part of the track 4). The guide plate 40G is a plate-shaped sensor with a built-in guide line Y. The guide line Y communicates with the guide core 37 of the traveling vehicle 6 (described later). The guide line Y is a loop-shaped communication line (conductive line). The guide line Y is used, for example, to determine which of the multiple traveling vehicles 6 passes the meeting point P first in the merging area G (see Figure 1) of the track 4. As shown in Figure 1, track 4 consists of multiple walking routes 2. These multiple walking routes 2 (here, walking routes 2A and 2B) converge at a confluence point P within a confluence region G. The confluence region G is the area including the confluence point P. The confluence region G corresponds to a guide line region where guide lines Y are provided around the confluence point P along the walking routes 2. As shown in Figures 1 and 2, the mobile vehicle 6 travels along the track 4, transporting items 10. The mobile vehicle 6 is configured to carry items 10. The mobile vehicle 6 is an elevated mobile unmanned transport vehicle. There is no particular limit to the number of mobile vehicles 6 in the mobile vehicle system 1; there can be multiple mobile vehicles. The mobile vehicle 6 has a traveling unit 18, a main body 7, an indicator (display) 80, a camera unit 8, and a control unit 50. The traveling unit 18 is configured to include a motor, etc., to move the traveling vehicle 6 along the track 4. The main body 7 has a central frame 22, a lateral feed unit 24, an θ driver 26, a lifting drive unit 28, a lifting unit 30, a main body cover 33, and a guide core 37. The central frame 22 supports the lateral feed unit 24, the θ driver 26, the lifting drive unit 28, and the lifting unit 30. The lateral feed unit 24 feeds the θ driver 26, the lifting drive unit 28, and the lifting unit 30 laterally in a direction perpendicular to the traveling direction of the track 4. The θ driver 26 causes at least one of the lifting drive unit 28 and the lifting unit 30 to rotate within a predetermined angle range in the horizontal plane. The lifting drive unit 28 raises and lowers the lifting unit 30 by winding and unwinding the lifting material such as steel wire, rope, or belt. A chuck is provided in the lifting unit 30, allowing for easy handling and release of the item 10. The main body covers 33 are respectively installed at the front and rear of the traveling vehicle 6. The main body covers 33 allow claws (not shown) to protrude and prevent the items 10 from falling during transport. The main body covers 33 have a front cover 34 installed at the front of the traveling vehicle 6 in the direction of travel and a rear cover 35 installed at the rear. The front cover 34 is roughly isosceles trapezoidal in shape when viewed from above, mainly having a front 34a facing outward (front) and a rear 34b facing inward (rear) to the side where the lifting part 30 is installed. The rear cover 35 is roughly isosceles trapezoidal in shape when viewed from above, mainly having a rear 35a facing outward (rear) and a front 35b facing inward (front) to the side where the lifting part 30 is installed. A pair of guide cores 37 are provided in the central frame 22. The guide cores 37 transmit and receive signals via the guide line Y of the guide line plate 40G. The indicator 80 is configured to switch between an on and off state. The light source of the indicator 80 is an LED bulb, halogen bulb, fluorescent bulb, or incandescent bulb, etc. The illumination control in each area is performed by the control unit 50. The indicator 80 displays and outputs information related to the required time, described later, to other vehicles 6 following it on the same travel route 2 as its own vehicle 6. The indicator 80 corresponds to an information output device that outputs the required time information to other vehicles 6 following it. The imaging unit 8 is positioned in front of the front cover 34a of the main body 7, so that the imaging range covers the front of its own traveling vehicle 6. The imaging unit 8 is a camera or light sensor including a lens and an imaging element that converts light entering from the lens into an electrical signal. The imaging unit 8 captures images of the leading traveling vehicle 61, which is on the same traveling route 2 as its own, with the indicator 80 of another traveling vehicle 6 (the first traveling vehicle, hereinafter also referred to as "the leading traveling vehicle 61") preceding its own traveling vehicle 6 included in the captured image. The imaging unit 8 captures images including a display related to the required time information. The imaging unit 8 corresponds to an information input device that inputs the required time information from the leading traveling vehicle 61. The control unit 50 is an electronic control unit composed of a CPU (Central Processing Unit), ROM (Read Only Memory), and RAM (Dynamic Random Access Memory). The control unit 50 controls various movements of the traveling vehicle 6. Specifically, the control unit 50 controls the traveling unit 18, the lateral feed unit 24, the θ driver 26, the lifting drive unit 28, the lifting unit 30, the indicator 80, and the camera unit 8. The control unit 50 can be configured as software that loads a program stored in ROM into RAM and executes it via the CPU. The control unit 50 can also be configured as hardware composed of circuits, etc. The control unit 50 communicates with the controller 60 via wired or wireless communication. When its own vehicle 6 enters the merging area G, the control unit 50 communicates via the guide core 37 through the guide line Y to determine whether there are other vehicles 6 (hereinafter referred to as "opposing vehicles 62") traveling on a different travel route 2 than its own vehicle 6 in the merging area G. When the control unit 50 determines that there is an oncoming vehicle 62 in the merging area G (i.e., its own vehicle 6 enters the merging area G after the oncoming vehicle 62), it performs a locking control to decelerate its own vehicle 6 and stop it at a stopping point T. The stopping point T is a location near a predetermined merging point P. The stopping point T is not particularly limited and can be set arbitrarily. On the other hand, when the control unit 50 determines that there is no oncoming vehicle 62 in the merging area G (i.e., its own vehicle 6 enters the merging area G before the oncoming vehicle 62), it causes its own vehicle 6 to pass through the merging point P without stopping at the stopping point T. That is, in the vehicle system 1, control is performed to stop vehicles 6 traveling on other routes 2 at stopping points T until vehicles 6 traveling on one route 2 pass through the merging area G. In this embodiment, when its own vehicle 6 passes through the merging point P (without stopping at the stopping point T) in the merging area G, the control unit 50 calculates the time required for its own vehicle 6 to pass through (leave) the merging area G. For example, the control unit 50 calculates the time required for its own vehicle 6 to pass through the merging area G as quickly as possible based on information related to its current speed and current position, map information related to the travel route 2, and various other information. The control unit 50 controls the indicator 80 to display the required time information related to the calculated required time. That is, the control unit 50 outputs the required time information to other vehicles 6 following its own vehicle 6. The display method of the indicator 80 is not particularly limited. Any method related to the required time information can be used. When the control unit 50 captures a display related to the required time information shown on the indicator 80 of the advance vehicle 61 via the imaging unit 8, it obtains the required time information from the captured image. For example, the control unit 50 performs image recognition processing on the captured image from the imaging unit 8 and can obtain the required time information based on the result. The image recognition processing is not particularly limited, and various known image recognition processing methods can be used. If the control unit 50 obtains the required time information of the preceding vehicle 61 before its own vehicle 6 enters the merging area G, it determines whether its own vehicle 6 can enter the merging area G within the required time. Then, if the time until its own vehicle 6 reaches the merging area G is shorter than the required time information, the control unit 50 determines that its own vehicle 6 can enter the merging area G. The determination of whether its own vehicle 6 can enter the merging area G within the required time can also be based on the premise that its own vehicle 6 accelerates. If the control unit 50 determines that its own vehicle 6 can enter the merging area G within the required time, it causes its own vehicle 6 to enter the merging area G without decelerating below the speed limit, so as to closely follow the preceding vehicle 61. On the other hand, if the control unit 50 determines that its own vehicle 6 cannot enter the merging area G within the required time, it causes its own vehicle 6 to decelerate below the speed limit before entering the merging area G. The speed limit is the speed at which the vehicle 6 can stop at the stopping point T. For example, the speed limit is an upper limit speed determined based on the deceleration performance of the vehicle 6, that is, the upper limit speed at which the vehicle 6 can stop at the stopping point T when entering the merging area G. The controller 60 is an electronic control unit consisting of a CPU, ROM, and RAM. The controller 60 can be configured as software that loads a program stored in ROM into RAM and executes it via the CPU. The controller 60 can also be configured as hardware consisting of circuits. The controller 60 sends a transport command for transporting the item 10 to the traveling vehicle 6. Next, an example of travel control for the traveling vehicle 6 in the traveling vehicle system 1 will be described. In this description, the travel control of the traveling vehicle 6 traveling on the travel route 2A until it enters the merging area G will be explained in detail using the flowchart in Figure 4, i.e., the travel control of the traveling vehicle 6 by the control unit 50. Furthermore, the traveling vehicle 6, which will also be the object of travel control, is referred to as the "control object traveling vehicle 63". First, it is determined whether the controlled object moving vehicle 63 can obtain the required time information from the preceding moving vehicle 61, which is scheduled to pass through the meeting point P within the meeting area G (step S1). In step S1, image recognition is performed on the display of the indicator 80 of the preceding moving vehicle 61 in the captured image projected onto the imaging unit 8, and as a result, it is determined whether the required time information of the preceding moving vehicle 61 can be obtained. If the result is "yes" in step S1, based on the obtained required time information, it is determined whether the controlled object moving vehicle 63 can enter the meeting area G within the required time (step S2). If step S2 is "yes", the controlled object moving vehicle 63 is not decelerated below the limit speed, and the controlled object moving vehicle 63 is controlled to catch up with the preceding moving vehicle 61, so that the controlled object moving vehicle 63 enters the merging area G (step S3). In step S3, the speed of the controlled object moving vehicle 63 can be kept constant or accelerated. Alternatively, in step S3, the controlled object moving vehicle 63 can be decelerated to a speed higher than the limit speed. On the other hand, if step S1 or step S2 is "no", the controlled object moving vehicle 63 is decelerated below the limit speed and enters the merging area G (step S4). In the above, the preceding moving vehicle 61 corresponds to the first moving vehicle, and the controlled object moving vehicle 63 corresponds to the second moving vehicle. In the above-described vehicle system 1, before the leading vehicle 61, which is traveling on route 2A in the merging area G, passes through the merging area G, the opposing vehicle 62, which is traveling on a different route 2B than the leading vehicle 61, is prevented from entering the merging point by a locking control. Under this prohibited state, if the control object vehicle 63, which is traveling on the same route 2A as the leading vehicle 61, can enter the merging area G (i.e., can enter the merging area G within the required time), there is no concern that the control object vehicle 63 and the opposing vehicle 62 will come into contact at the merging point P. Therefore, it is not necessary to decelerate the control object vehicle 63 below the speed limit. Thus, for example, the control object vehicle 63 can enter the merging area G at a high speed. Therefore, according to the vehicle system 1, the extension of travel time can be suppressed. For example, it is possible to suppress the deceleration of the control object vehicle 63 entering the merging area G even when there is no opposing vehicle 62, thereby shortening the transport time. In addition, when the merging area G is narrow (the distance from its entrance to the stop point T is short), it is necessary to further decelerate the control object vehicle 63 before entering the merging area G. Therefore, this embodiment is particularly effective in such cases. The vehicle system 1 includes an indicator 80, which serves as an information output device installed on the vehicle 6 and used to output required time information to other vehicles 6 following the vehicle 6. The vehicle system 1 also includes a camera unit 8, which serves as an information input device installed on the vehicle 6 and used to input required time information from a preceding vehicle 61. In this case, required time information can be directly transmitted and received between the vehicles 6. Furthermore, even in environments where wireless communication is difficult, required time information can also be transmitted and received between the vehicles 6. If the controlled object moving vehicle 63 fails to enter the merging area G within the required time, the moving vehicle system 1 decelerates the controlled object moving vehicle 63 to below the limit speed. Therefore, it can account for the possibility that the opposing moving vehicle 62 may enter the merging point P, and thus stop the controlled object moving vehicle 63 at the stopping point T, decelerating the controlled object moving vehicle 63 to below the limit speed. In the vehicle system 1, the merging area G corresponds to the guide line area. In this case, the guide line area can be used as the merging area G to form the system. The above description describes one embodiment, but the present invention is not limited to the above embodiment. Various modifications can be made without departing from the spirit of the invention. In the above embodiments, an indicator 80 is used as an information output device, but any other device that utilizes wireless communication, such as a transmitting device, can be used as long as it can output information. An imaging unit 8 is used as an information input device, but any other device that can input information, such as a receiving device, can also be used. The imaging unit 8 is not particularly limited; a stereo camera, a TOF camera, or other imaging device with distance measurement capabilities can also be used. In the above embodiments and variations, an elevated mobile vehicle was described as an example of a mobile vehicle, but other examples of mobile vehicles include unmanned mobile vehicles that travel on tracks or lane markings on the ground or platforms, and stacking cranes, etc. In the above embodiments and variations, the control unit 50 for controlling the traveling vehicle 6 is described as being provided in the main body 7 of each traveling vehicle 6. However, it can also be configured in a location separate from the main body 7 and capable of communication via wired or wireless communication (e.g., controller 60). In such a case, the control unit 50 is not provided for each of the multiple traveling vehicles 6, but is configured to control multiple traveling vehicles 6 simultaneously. 1: Walking vehicle system 2: Walking route 2A: Walking route 2B: Walking route 4: Track 5: Control unit 6: Walking vehicle 7: Main body 8: Camera unit 10: Item 18: Walking unit 22: Central frame 24: Lateral feed unit 26: θ driver 28: Lifting drive unit 30: Lifting unit 33: Main body cover 34: Front cover 34a: Front 34b: Rear 35: Rear cover 35a: Rear 35b: Front 37: Guide core 40: Guide line plate 40B: Lower part 40C: Side part 40D: Top part 40G: Guide line plate 50: Control unit 60: Controller 61: Leading walking vehicle 62: Opposing walking vehicle 63: Controlling object walking vehicle 80: Indicator G: Meeting area P: Meeting point T: Stop point Y: Guide line [Figure 1] is a schematic diagram showing the configuration of a vehicle system according to one embodiment. [Figure 2] is a side view of the vehicle. [Figure 3] is a three-dimensional cross-sectional view showing the track and guide wire. [Figure 4] is a flowchart illustrating an example of travel control implemented by a traveling vehicle before entering the merging area.

Claims

1. A vehicle system that, in a convergence area comprising multiple convergence points of travel routes, controls vehicles traveling on other travel routes to stop at a stop point near the convergence point until a vehicle traveling on one travel route passes through the convergence area, characterized in that the vehicle system calculates a required time, which is the time from the convergence area until a first vehicle passing through the convergence point passes through the convergence area; and if a second vehicle following the first vehicle and traveling on the same travel route outside the convergence area can enter the convergence area within the required time, the second vehicle enters the convergence area without decelerating to a speed below a limit that would allow it to stop at the stop point, the vehicle system comprising: an information output device disposed on the vehicle for outputting information related to the required time to other vehicles following the vehicle; and an information input device disposed on the vehicle for inputting information related to the required time from other vehicles preceding the vehicle.

2. The vehicle system as described in claim 1, wherein, The aforementioned information output device is a display, and the aforementioned information input device is a camera or a light sensor.

3. The vehicle system as described in claim 1 or 2, wherein, If the second traveling vehicle is unable to enter the rendezvous area within the required time, the second traveling vehicle shall be decelerated to below the speed limit.

4. The vehicle system as described in claim 1 or 2, wherein, The aforementioned meeting area corresponds to the guide line area, which has guide lines set around the aforementioned meeting point along the aforementioned walking route.

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