Autonomous transport vehicles

Abstract

To provide an autonomous transport vehicle that can shorten the time required for the simultaneous transport and transfer of multiple packages, and that can respond to changes in the layout of transport routes inexpensively and quickly. [Solution] The autonomous transport vehicle 1 comprises a mobile robot unit 2 equipped with an autonomously mobile trolley unit 21, a cargo compartment unit 3 provided on the mobile robot unit 2 that can accommodate multiple loads A, and a transfer unit 4 provided inside the cargo compartment unit 3 for transferring loads A to and from an external loading / unloading unit B. The transfer unit 4 is configured to have multiple holding units 6 that individually hold loads A at different height positions, a forward / backward unit 7 that individually moves the holding units 6 back and forth between the cargo compartment unit 3 and the loading / unloading unit B, and a lifting / lowering unit 5 that moves each holding unit 6 and each forward / backward unit 7 up and down within the cargo compartment unit 3.

Description

Technical Field

[0004]

[0001] The present invention relates to an autonomous driving transport vehicle such as an autonomous driving robot that holds a load to be transported and autonomously travels, and raises and lowers the load at the destination.

Background Art

[0002] In recent years, with the progress of unmanned and automated distribution of goods in logistics, factories, etc., and the spread and expansion of EC (electronic commerce), autonomous driving transport vehicles such as automated guided vehicles (AGVs) and autonomous mobile robots (AMRs) have become popular, and it is expected that the introduction of autonomous driving transport vehicles will continue to increase in the future. For example, in semiconductor manufacturing factories, autonomous driving transport vehicles are also being used. As an example, the self-propelled transport device disclosed in Patent Document 1 has a configuration in which a cassette or the like, which is a type of container for housing semiconductor wafers, is grasped by controlling an arm mounted on a traveling robot, picked up from a storage facility, and transported in a state of being loaded on a loading table that forms a part of the outer wall of the self-propelled transport device.

[0004] ​​​​Furthermore, semiconductor manufacturing plants have conventionally used overhead transport devices called OHT (Over Head Transport) or OHS (Over Head Shuttle), which travel along tracks laid on the ceiling, as disclosed in Patent Document 2. These overhead transport devices consist of a cart that moves along the tracks and an arm provided on the cart for gripping. The arms grip the flange portion at the top of a container that houses semiconductor wafers, such as a FOUP (Front Opening Unified Pod), and suspend it while the cart travels along the tracks, between the load port, which is the entrance and exit point for semiconductor wafers in semiconductor manufacturing equipment, and the load port or installation location of the next semiconductor manufacturing equipment within the factory. In particular, while the front-end processes in semiconductor manufacturing are standardized based on SEMI standards, and the transport of semiconductor wafers housed in FOUPs using the above-mentioned overhead transport devices is the mainstream, there are no specific standards for the back-end processes of semiconductor manufacturing, and currently manual transport is the mainstream method. This subsequent process has traditionally been carried out in countries or regions with low labor costs, but there is a growing movement to bring it back to the home country, even if labor costs are higher, in order to avoid geopolitical risks, and the need for automation is increasing.

[0005] Furthermore, with the increasing demand for high-performance ICs for applications such as AI, data centers, and autonomous driving, a new concept called the mid-stage process is gaining attention. This is an area in semiconductor manufacturing where the distinction between front-end and back-end processes becomes blurred, particularly when manufacturing advanced packages such as chiplets. In the mid-stage process, instead of the conventional 300mm diameter wafers, it is anticipated that 300mm square or large 600mm square rectangular substrates will be handled to increase the number of semiconductor chips. In particular, the containers (PANEL FOUPs, etc.) used to house these large rectangular substrates are expected to be considerably heavier than conventional containers. Moreover, various processing methods for the mid-stage process are still being proposed, and frequent changes in the layout of manufacturing equipment are anticipated in the future. [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] Japanese Patent Publication No. 2021-074791 [Patent Document 2] Japanese Patent Publication No. 2024-010483 [Overview of the Initiative] [Problems that the invention aims to solve]

[0007] By the way, when transferring cassettes using a self-propelled transport device with a single robotic arm, as shown in Patent Document 1, for example, a series of operations must be performed sequentially for each container, such as picking up a container, such as a cassette containing semiconductor wafers that have undergone some processing in semiconductor manufacturing, and placing it on the loading platform, and then placing a container, such as a cassette containing unprocessed semiconductor wafers, that has been carried by the self-propelled transport device, onto the load port. Therefore, the cycle time for container exchange (container transport efficiency and transfer efficiency) becomes an issue. Furthermore, the positioning accuracy of the robotic arm decreases depending on the number of joints and motors mounted on it, so high-precision positioning accuracy is required, which affects the cycle time. In addition, when transferring large rectangular substrates stored in containers, the robotic arm and loading platform (the part that houses the containers) must also be made larger according to the weight, size, and quantity of the cassettes, resulting in a self-propelled transport device of an unrealistic size and weight, making container transport practically difficult. Furthermore, since the container loading platform is enlarged based on the direction of travel and the efficiency of the transfer operation, the loading platform is basically arranged around the robot arm, increasing the size of the self-propelled transport device (especially the lateral size), which may cause problems in the semiconductor manufacturing process, particularly on the travel surface of the transport device. In addition, while the shape of the part to be gripped for transport varies considerably depending on the type of container, a typical self-propelled transport device is equipped with an arm specifically designed for gripping the part to be gripped of a particular container. As a result, the type of container that can be transported by a single self-propelled transport device is effectively limited to one type.

[0008] Furthermore, the overhead transport device shown in Patent Document 2 can only carry one container at a time, meaning that, for example, two carts are required to transfer two containers. In other words, two carts are needed for the transfer, in the order of positioning the first cart, retrieving the container, positioning the second cart, and installing the container. In addition, the positioning operation for each cart is required a total of two times, which takes a lot of time for the positioning operation when transferring containers, and the cycle time for container exchange becomes a problem. Moreover, even with overhead transport devices, the shape of the part of the container to be gripped, such as the flange, that can be gripped by the arm is usually limited to essentially one type, and the device is designed to transport only that type of container by gripping the part to be gripped, which is set to a specific width dimension, so different types of containers require overhead transport devices equipped with different arms. In addition, with overhead transport devices, the degree of freedom of the track laid on the ceiling is low, and the track arrangement needs to be changed to accommodate frequent changes in the layout of the manufacturing equipment, which is expected to result in high construction costs.

[0009] Furthermore, autonomous transport vehicles navigate while recognizing their approximate position, and after stopping near the loading platform or other cargo transfer location, fine adjustments to the transfer position are necessary to ensure accurate transfer. In particular, in the case of differential two-wheel drive autonomous transport vehicles, which have a relatively simple driving mechanism, the main movement actions are driving in the direction of travel that matches the rotation direction of the wheels and turning. Therefore, after approaching and stopping at the transfer position, the vehicle has to adjust its position by repeatedly turning and moving forward or backward, and this adjustment takes a relatively long time. In addition, when making fine adjustments to the transfer position, the moment of inertia caused by the weight of the autonomous transport vehicle and the weight including the cargo makes it difficult for the autonomous transport vehicle to stop or start, which also adds to the time required for position adjustment.

[0010] Thus, the following problems—such as the limitation of transporting only one type or number of containers at a time, the time required for container transfers, the difficulty in transporting heavy containers, the inability to transport containers with specific gripping parts using a single transport device, the difficulty in adapting to changes in the transport route layout, and the time required for adjusting the transfer position—are not unique to autonomous transport for container transport in semiconductor manufacturing plants, but are common problems for various types of autonomous transport that are increasingly used to transport various kinds of cargo. Therefore, the present invention has been made with these problems in mind, and its main objective is to provide an autonomous transport vehicle that can shorten transport time and transfer time by allowing multiple loads to be transported simultaneously. Furthermore, it aims to enable the transport and transfer of heavy cargo, the simultaneous handling of multiple loads with different gripping parts, and the easy and quick adjustment of the cargo transfer position. [Means for solving the problem]

[0011] In other words, the autonomous transport vehicle according to the present invention comprises a mobile robot section equipped with a trolley section capable of autonomous movement, a cargo compartment section provided on the mobile robot section and capable of accommodating multiple loads in a part of its internal space, and a transfer section provided within the cargo compartment section for transferring loads between the cargo compartment section and an external loading / unloading section, wherein the transfer section is configured to include a plurality of holding sections that individually hold loads at different height positions, an advance / return section that individually moves the holding sections back and forth between the cargo compartment section and the loading / unloading section, and a lifting / lowering section that moves each holding section and each advance / return section up and down within the cargo compartment section.

[0012] With the autonomous transport vehicle of the present invention, for example, multiple packages can be stored at different heights in the cargo compartment, each held by its respective holding section, and transported by the autonomous robot section. The forward / backward section and lifting section are then operated to transfer the packages to an external loading / unloading section. After the loading / unloading section or the autonomous robot has moved, another package can be stored in the cargo compartment from another loading / unloading section, held by its holding section, and then transported by the autonomous robot section. This enables the simultaneous transport of multiple packages, which was not possible with conventional transport devices such as self-propelled transport devices or overhead transport devices, improving transport capacity and shortening transport and transfer times. The packages to be transported may contain contents or be empty, and only one package may be stored in the cargo compartment during transport. Furthermore, because the cargo compartment has a structure that accommodates multiple packages at different heights, it becomes possible to transport and transfer larger packages than before without drastically increasing the planar dimensions of the autonomous transport vehicle. Furthermore, since the mobile robot unit is capable of autonomous movement, it does not require a laid track like an overhead transport system, and can flexibly adapt to changes in the layout of the transport route.

[0013] In the autonomous transport vehicle of the present invention, the lifting section is provided with two lifting axes arranged in a vertical position, and each forward and backward movement section can be configured with an independently extendable and retractable arm that has a holding part attached to its tip and a base part attached to be able to move up and down along each lifting axis. With such a configuration, an autonomous transport vehicle can accommodate and transport two loads in the cargo compartment, and since it is equipped with a transfer section that has two sets of combinations of lifting axes and arms and holding parts for the forward and backward movement sections, the movement of the arms relative to these two sets of lifting axes can be made independent, and the forward and backward movement of the arms and holding parts can be made independent, thereby shortening the load transfer time (transfer time, especially the positioning time during lifting).

[0014] On the other hand, in the autonomous transport vehicle of the present invention, a single lifting axis is provided in a vertical position in the lifting section, and each forward and backward section can be composed of two arms that are extendable in the front-to-back direction, with a holding part attached to the tip and the base end mounted so as to be able to move up and down along the lifting axis. With such a configuration, two loads can be stored and transported in the cargo compartment, and since the transport section is equipped with a transfer section that has two sets of combinations of arms and holding parts for the forward and backward sections for the single lifting axis of the lifting section, compared to the autonomous transport vehicle equipped with the lifting axis of the lifting section and a transfer section equipped with two sets of combinations of arms and holding parts for the forward and backward sections, the load transfer time is longer because the lifting and lowering movements of the two arms relative to the lifting axis are simultaneous, but the forward and backward movements of the arms and holding parts can be performed independently, and since there is only one lifting axis, it leads to space saving and reduced manufacturing costs, and moreover, loads can be transferred in a significantly shorter time than conventional self-propelled transport devices and overhead transport devices.

[0015] Furthermore, the holding section of the autonomous transport vehicle of the present invention can be configured to include a fork section having a pair of holding pieces that hold a portion of the cargo to be held in the front-rear and width directions, and an expandable / contractable section that can change the spacing between the holding pieces. With a holding section equipped with such a fork section, the load-bearing capacity can be improved compared to conventional self-propelled transport devices and overhead transport devices, making it possible to transport and transfer heavy or large-sized cargo that could not be handled by these transport devices due to weight limitations. Moreover, since the spacing between the pair of holding pieces of the fork section can be changed by expanding or contracting them with the expandable / contractable section, it is possible to hold and handle cargo in the width direction to accommodate various portions of the cargo that have different width dimensions. In the autonomous transport vehicle of the present invention, at least one of the multiple holding sections can be a holding section equipped with such a fork section and expandable / contractable section.

[0016] In a holding section that holds a load in the width direction, the fork section can be provided with an inner holding section that holds the load from the outside inward and an outer holding section that holds the load from the inside outward, depending on the part of the load to be held, and a stopper section erected between the inner and outer holding sections. By configuring the fork section in this way, it becomes possible to hold loads with the same fork section whether the part of the load to be held is shaped to be held from the inside in the width direction or from the outside in the width direction, and the stability of the holding state can be improved by placing the side of the load against the stopper section regardless of whether the load is held by the inner or outer holding section.

[0017] Furthermore, in the autonomous transport vehicle's mobile robot section of the present invention, a fine adjustment unit is mounted on the trolley to adjust the transfer position to the loading / unloading section when the vehicle is stopped and approaching the loading / unloading section. This fine adjustment unit is configured to include a rotation adjustment unit that rotates the cargo compartment so that it faces the loading / unloading section directly, and a left-right adjustment unit that aligns the widthwise center of the loading / unloading section with the widthwise center of the cargo compartment. This configuration allows for quick position adjustments to transfer cargo without moving the stopped trolley. When the weight of the cargo or the autonomous transport vehicle itself is large, the ability to adjust the transfer position in a short time is a significant advantage. The ability to adjust the position of the cargo compartment using the fine adjustment unit while the trolley is stopped reduces the moment of inertia by the difference between the total weight of the autonomous transport vehicle and the weight of the trolley, thereby reducing the load and allowing for rotational movement by the rotation adjustment unit and movement in the widthwise direction by the left-right adjustment unit. In particular, if the bogie section employs a differential two-wheel drive system, a significant advantage can be gained: a reduction in the time required for precise transfer position adjustment. [Effects of the Invention]

[0018] According to the autonomous mobile transport vehicle of the present invention, the traveling robot unit can be autonomously traveled and transported while accommodating a plurality of loads in the load compartment at different heights. In addition, the advancing / retreating unit and the elevating unit of the transfer unit are operated to transfer the load held by the holding unit between the external loading / unloading unit and the load compartment. Therefore, it is possible to shorten the time required for simultaneous transportation and transfer of a plurality of loads, that is, to improve the transportation capacity and transfer efficiency. Moreover, since the traveling robot unit travels autonomously with the load on the load compartment and the transfer unit, it is possible to respond to changes in the layout of the transportation route at low cost and quickly.

Brief Description of the Drawings

[0019] [Figure 1] Right side view showing the autonomous mobile transport vehicle according to an embodiment of the present invention with a container accommodated. [Figure 2] Side view showing the autonomous mobile transport vehicle of the embodiment. [Figure 3] Front view showing the autonomous mobile transport vehicle of the embodiment. [Figure 4] Perspective view of the autonomous mobile transport vehicle of the embodiment as viewed obliquely from the front side. [Figure 5] Diagram schematically showing the configuration of the traveling robot unit in the autonomous mobile transport vehicle of the embodiment. [Figure 6] Front view showing the transfer unit of the first example of the embodiment. [[ID=2,5]] [Figure 7] Side view showing the transfer unit of the example. [Figure 8] Rear view showing the transfer unit of the example. [Figure 9] Perspective view showing the transfer unit of the example. [Figure 10] Perspective view showing the holding unit in the embodiment in an enlarged manner. [Figure 11] Front view showing the holding unit in the embodiment in an enlarged manner. [Figure 12] Side view showing the holding unit in the embodiment in an enlarged manner. [Figure 13] Perspective view showing a state in which a container is held by the inner holding unit of the upper holding unit in the embodiment. [Figure 14]A perspective view showing the state in which the container is held by the outer holding part of the upper holding part in the same embodiment. [Figure 15] A front view showing the transfer unit of the first embodiment in which containers are held in two stages, upper and lower. [Figure 16] A perspective view showing the state in which containers are held and transferred in two stages, upper and lower, in the transfer section of the first embodiment. [Figure 17] A front view showing the transfer unit of the first embodiment with a container held in the upper position. [Figure 18] This is a perspective view showing the state in which a container is held and transferred in the upper section of the transfer unit of the same embodiment. [Figure 19] This is a front view showing the transfer section of the same embodiment with the container held in the lower section. [Figure 20] This is a perspective view showing the state in which a container is held and transferred in the lower section of the transfer unit of the same embodiment. [Figure 21] A flowchart illustrating the operation during container transfer in an autonomous transport vehicle of the same embodiment, to which the same embodiment is applied. [Figure 22] A front view showing the transfer section of the second embodiment of the same model. [Figure 23] A side view showing the transfer section of the same embodiment. [Figure 24] A rear view showing the transfer section of the same embodiment. [Figure 25] This is a perspective view showing the containers held in two stages, upper and lower, in the transfer section of the same embodiment. [Figure 26] A flowchart illustrating the operation during container transfer in an autonomous transport vehicle of the same embodiment, to which the same embodiment is applied. [Modes for carrying out the invention]

[0020] Hereinafter, one embodiment of the present invention will be described with reference to the drawings. As shown in Figures 1, 2, 3, and 4, the autonomous transport vehicle 1 according to this embodiment autonomously travels in a semiconductor manufacturing plant to transport transport containers A, such as FOUPs for containing semiconductor wafers and PANEL FOUPs for containing rectangular substrates, as cargo, and is used to transfer containers A between load ports B, which are the entrances and exits to semiconductor manufacturing equipment, and other predetermined loading and unloading sections (see Figures 21 and 26). This autonomous transport vehicle 1 consists of a mobile robot section 2, a cargo compartment section 3 mounted on the mobile robot section 2 to contain containers A, and a transfer section 4 (or 40) installed inside the cargo compartment section 3.

[0021] As shown in Figures 1 to 4, the mobile robot unit 2 is mainly composed of a carriage unit 21 that has sufficient load-bearing capacity to support the load of the cargo compartment unit 3 and transfer unit 4 (or 40) mounted on top, and the container A housed in the cargo compartment unit 3. The carriage unit 21 is flat and has a small height, forming a roughly rectangular parallelepiped shape, and employs a differential two-wheel drive mechanism equipped with two drive wheels 22 and multiple (four in the illustrated example) casters 23, enabling it to travel smoothly within the flat semiconductor manufacturing plant. In terms of travel, it is configured to autonomously travel along a predetermined travel path within the semiconductor manufacturing plant, using data such as images and measurements acquired by sensors (not shown), such as a camera 2a, a LiDAR 2b (Light Detection and Ranging), and laser displacement meters 2c positioned to the left and right of the camera 2a, according to an autonomous travel program in the travel control unit mounted on the mobile robot unit 2. Figure 1 shows the camera 2a, LiDAR 2b, and laser displacement meter 2c positioned on the front side of the mobile robot unit 2. These sensors are similarly positioned on the rear side of the mobile robot unit 2 and are used for the forward and reverse movement of the mobile robot unit 2. Furthermore, when the mobile robot unit 2 transports container A to load port B, etc., the autonomous transport vehicle 1 is driven so that the front side of the cargo compartment unit 3 (described later) is at the rear, in order to prevent particles and dust from entering the autonomous transport vehicle 1.

[0022] The mobile robot unit 2 is equipped with a fine adjustment unit 24 that finely adjusts the transfer operation position at its own position so that container A can be properly transferred when it moves to a designated position (a position near load port B) relative to the loading / unloading section such as load port B and stops. As schematically shown in Figures 4 and 5, the fine adjustment unit 24 consists of a swivel adjustment unit 25 and a left / right adjustment unit 26, which are located between the trolley unit 21 and the cargo compartment unit 3. The swivel adjustment unit 25 has the function of aligning the front side of the cargo compartment unit 3 (the side on which container A is transferred) with the loading / unloading section such as load port B by swiveling the member located above the trolley unit 21 (swivel adjustment unit 25, left / right adjustment unit 26, cargo compartment unit 3 and transfer unit 4) when the mobile robot unit 2 has traveled to the vicinity of the loading / unloading section such as load port B and stopped, thereby aligning the front side of the cargo compartment unit 3 (the side on which container A is transferred) with the loading / unloading section such as load port B (so-called "parallel alignment"). The left-right adjustment unit 26 has the function of aligning the widthwise center of the cargo compartment 3 with the widthwise center of the loading / unloading area such as the load port B. When operating the swivel adjustment unit 25 and the left-right adjustment unit 26, in addition to the camera 2a, LiDAR 2b, and laser displacement meter 2c, images captured by the overhead camera 2d, which is attached to the left and right support columns 3d on the front side of the cargo compartment 3 and takes pictures of the area diagonally downwards, are used. By providing such a swivel adjustment unit 25 and left-right adjustment unit 26, the autonomous transport vehicle 1 estimates its approximate self-position and reaches a position close to the loading / unloading area such as the load port B, and before starting to transfer container A, the entire autonomous transport vehicle 1 does not need to adjust its self-position by repeatedly performing a series of operations such as swiveling, reversing, swiveling, estimating its own position, and moving forward to transfer container A. Instead, the entire autonomous transport vehicle 1 remains stationary, and only the upper structure above the trolley 21 is swiveled and moved left and right, enabling the transfer of container A in a short time. In this way, autonomous driving control, fine adjustment control of transferable positions, and transfer control (driving control unit and transfer control unit) of the mobile robot unit 2 are performed by a computer that functions as a control unit mounted on the mobile robot unit 2.

[0023] As shown in Figures 1 to 4, the cargo compartment 3 is a large, roughly rectangular box-shaped structure mounted above the traveling robot unit 2 (above the swivel adjustment unit 25 and the left / right adjustment unit 26). It houses the transfer unit 4 and can accommodate containers A (A1, A2) in two layers, upper and lower. In this embodiment, the cargo compartment 3 has a structure in which a cover is attached to the outside of the frame structure. The frame structure mainly consists of a bottom plate 3a that supports the entire transfer unit 4 (or 40), a pair of left and right back plates 3b erected on the rear end side of the bottom plate 3a, vertical and horizontal back frames 3c installed on the back side of the back plates 3b, a total of four support columns 3d erected along both the left and right sides of the bottom plate 3a at its front and rear ends, and beam members 3e and a top plate 3f that connect the back frames 3c and the four support columns 3d at their upper ends. The cover that encloses this frame structure consists of an upper panel 31, a rear panel 32, and left and right side panels 33, 33. This is to prevent particles, dust, and other debris from adhering to container A when it travels through the semiconductor manufacturing plant, to prevent the contained containers A (A1, A2) from falling, and to prevent dust from entering the cargo compartment 3. The front side is left open without a panel to allow for loading and unloading of containers A (A1, A2) between the loading port B and other loading / unloading areas.

[0024] <First embodiment of the transfer unit 4> In the first embodiment of the transfer unit (transfer unit 4) in the autonomous transport vehicle 1 of this embodiment, as shown in Figures 1 to 4, one or two containers A can be accommodated in the cargo compartment 3, and the two holding units 6a and 6b (each of which may be holding a container A or not (empty)) can be raised and lowered independently to allow for individual transfer. As shown in Figures 6 to 9 (in each of these figures, the upper panel 31, rear panel 32, and left and right side panels 33, 33 of the cargo compartment 3 have been removed to make the configuration of the transfer unit 4 easier to see), the transfer unit 4 is configured within the frame structure of the cargo compartment 3 and consists of a lifting section 5 mainly composed of two lifting shafts 51, 52, holding sections 6 (6a, 6b) that hold two containers A (A1, A2) at different height positions, and two upper and lower moving sections 7 (7a, 7b) that move the holding sections 6 (6a, 6b) back and forth between the inside of the cargo compartment 3 and the loading / unloading section such as the load port B outside.

[0025] In the lifting section 5, the two lifting shafts 51 and 52 are erected spaced apart to the left and right at the rear end of the transfer section 4 (in front of each back plate 3b) which is at the back of the cargo compartment 3. They are each driven by independently operating rotary drive units 51a and 52a, and consist of ball screws with external threads that rotate around a vertical axis. One rotary drive unit 51a is located on the upper end side of the lifting shaft 51, and the other rotary drive unit 52a is located on the lower end side of the lifting shaft 52, so that ample space is secured for each to prevent interference with each other. Each of the rotary drive units 51a and 52a consists of motors 51b and 52b, gearboxes 51c and 52c containing gears that convert the rotation of motors 51b and 52b by 90° and transmit it to the lifting shafts 51 and 52, couplings 51d and 52d interposed between the gearboxes 51c and 52c and the lifting shafts 51 and 52, and sensors such as encoders (not shown) that measure the rotational speed and angular velocity of motors 51b and 52b, thereby precisely controlling the rotation of the lifting shafts 51 and 52.

[0026] At the base ends of the retractable sections 7 (7a, 7b), there are lifting blocks (not shown) fixed to movable elements with internal threads that are screwed onto each lifting shaft 51, 52, so as to move up and down by the rotation of each lifting shaft 51, 52. The movable elements and lifting blocks attached to the lifting shaft 51 are set at a relatively high position (upper level), while the movable elements and lifting blocks attached to the lifting shaft 52 are set at a relatively low position (lower level). Each lifting block has horizontal bars 71a, 71b fixed to it in a horizontal position, which are slightly shorter than the distance between the left and right support columns 3d on the rear end side. The rear ends of a pair of left and right arms 72a (upper level) and 72b (lower level), which extend in the front-rear direction, are fixed to each horizontal bar 71a, 71b. Each arm 72a, 72b has a configuration that allows it to extend and retract in the front-to-back direction, consisting of fixed arms 73a, 73b with a length approximately equal to the distance from the front surface of the front support column 3d to the rear surface of the rear support column 3d, and movable arms 74a, 74b that are engaged with each fixed arm 73a, 73b on their upper side so as to be slidable in the front-to-back direction. In this embodiment, in arm 72a, the left fixed arm 73a and the right movable arm 74a, and the left movable arm 74a and the right fixed arm 73a have substantially the same configuration, and in arm 72b, the left fixed arm 73b and the right movable arm 74b, and the left movable arm 74b and the right fixed arm 73b have substantially the same shape, so that the roles of the fixed side and the movable side are different for the left and right arms 72a, 72b. Each fixed arm 73a, 73b has a support bar 75 fixed to it that is approximately the same length as the fixed arms. Sliders 76 are attached to the front and rear ends of each support bar 75, allowing them to move vertically along the front and rear support columns 3d. With this configuration, rotating each lifting shaft 51, 52 causes the movable elements to move up and down, and consequently the crossbars 71a, 71b, arms 72a, 72b, support bars 75 and sliders 76 are guided along the support columns 3d and move up and down. In addition, each arm 72a, 72b has a ball screw, motor, and sensor (all not shown) built in to precisely control the forward and backward lengths (amount of protrusion from the cargo compartment 3) of each movable arm 74a, 74b relative to each fixed arm 73a, 73b.

[0027] As shown in detail in Figures 1-4, 6-9, and 10-12, the holding section 6 consists of an upper holding section 6a attached to the arm 72a and a lower holding section 6b attached to the arm 72b. In this embodiment, the cargo compartment 3 accommodates containers ranging from relatively small in width (e.g., a conventional 300mm wafer FOUP) to relatively large (e.g., a large 600mm square rectangular substrate PANEL FOUP) by the upper holding section 6a, which has a variable holding width, while only the relatively small container A1 is accommodated by the lower holding section 6b, which has a fixed holding width. In the illustrated examples, both containers A1 and A2 are schematically shown as rectangular parallelepipeds. If container A1 is a FOUP, it is provided with a flange (top robot flange) that is used when it is suspended and transported by a conventional overhead conveying device. However, in this embodiment, the held portion A1a, which is held by the holding portions 6a and 6b, is set to extend from the bottom surface to the side surface. Furthermore, in the case of container A2, the held portion A2a, which is held by the holding portion 6a, has flanges on the top surface that protrude to both the left and right sides.

[0028] The upper holding section 6a includes a horizontal support plate 61a fixed across the rear ends of the left and right movable arms 74a, 74a on the upper arm 72a of the reciprocating section 7a, a vertical support plate 62a fixed hanging down from the front end of the horizontal support plate 61a, and a fork section 63a for holding containers A (A1, A2). The fork section 63a has a pair of left and right holding pieces 64a, 65a, and the holding section 6a is provided with an expansion / contraction section 66a that changes the distance between these holding pieces 64a, 65a. The expansion / contraction section 66a is provided extending in the width direction from the lower end of the vertical support plate 62a and is equipped with a ball screw with double threads, a motor, a sensor, etc. (all not shown). The retaining pieces 64a and 65a are each attached via movable members such as nuts (not shown) screwed onto the ball screw of the expanding / contracting section 66a, and consist of hanging pieces 64a1 and 65a1, respectively, upright pieces 64a2 and 65a2 extending forward from the outer ends of the hanging pieces 64a1 and 65a1, and horizontal pieces 64a3 and 65a3 attached to the lower ends of the hanging pieces 64a1 and 65a1 and the upright pieces 64a2 and 65a2. By rotating the ball screw of the expanding / contracting section 66a, both retaining pieces 64a and 65a move simultaneously in directions toward each other (inward) or in opposite directions (outward), thereby allowing the distance between the retaining pieces 64a and 65a to be adjusted. To stably guide the movement of both holding pieces 64a and 65a, a slider 66a1 extending in the width direction is provided at a mid-height position on the front side of the vertical support plate 62a, and the rear sides of the hanging pieces 64a1 and 65a1 are engaged with it to allow movement in the width direction. Furthermore, by arranging the upright pieces 64a2 and 65a2 so that the upper surfaces of the inner and outer ends of each horizontal piece 64a3 and 65a3 are open, as shown in Figure 13, an inner holding portion 67a is formed that holds the side surface of the container A1, which is part of the held portion A1a, from the outside to the inside, while the horizontal pieces 64a3 and 65a3 are inserted in the front-rear direction into the bottom surface, which is part of the held portion A1a of the container A1 and held in place.In addition, as shown in Figure 14, the horizontal pieces 64a3 and 65a3 are inserted in the front-rear direction into the flange A2a of the container A2 to hold it, and an outer holding part 68a is formed to hold the A2a of the container A2 from the inside out, with the upright pieces 64a2 and 65a2 between the inner holding part 67a and the outer holding part 68a functioning as stoppers. Note that the hanging pieces 64a1 and 65a1 of the holding pieces 64a and 65a have different shapes to prevent interference when they are closest to each other, but the other parts have a symmetrical shape. Furthermore, in the outer holding part 68a, multiple notches 68a1 are formed in the front-rear direction on the outer edge of each horizontal piece 64a3 and 65a3, so that if there is an object to be inserted into the flange A2a of the container A2 (for example, a pole), it can be inserted to improve the stability of the hold.

[0029] As shown in Figures 1 to 4 and Figures 6 to 9, the lower holding section 6b consists of a horizontal support plate 61b fixed across the rear ends of the left and right movable arms 74b, 74b in the lower retractable section 7b, and a pair of left and right holding pieces 64b hanging down from the movable arms 74b, 74b at the front end of the horizontal support plate 61b. Each holding piece 64b consists of a horizontal tongue piece 64b1 fixed to the upper surface of the movable arm 74b, a hanging piece 64b2 formed by bending the inner edge of the horizontal tongue piece 64b1 downward, and a horizontal piece 64b3 formed by bending the inner edge of the hanging piece 64b2 inward. This horizontal piece 64b3 functions as an inner holding section 67b that holds the held portion A1a of the container A1 from the outside to the inside, while the hanging piece 64b2 functions as a stopper (see Figures 19 and 20).

[0030] In the autonomous transport vehicle 1 of this embodiment, various variations can be taken in how container A is housed in the cargo compartment 3 and how container A is held and transported by the holding parts 6 (6a, 6b) in the transfer section 4, but here we will describe a few of them. Figures 15 and 16 show the state in which container A1 is held by both the upper holding part 6a and the lower holding part 6b and housed in the cargo compartment 3. In this state, the inner holding part 67a of the holding part 6a is activated, and the left and right holding pieces 64a and 65a hold the bottom surface, which is part of the held part A1a of container A1, from the outside to the inside, and at the same time the upright pieces 64a2 and 65a2 are brought into contact with the side surface of container A1 from the outside and function as stopper parts. In the lower holding section 6b, the left and right horizontal pieces 64b3 that constitute the inner holding section 67b hold the bottom surface, which is part of the held section A1a of the container A1, from the outside inward, and at the same time, the hanging pieces 64b2 are brought into contact with the side surface of the container A1 from the outside, functioning as a stopper. Figure 17 shows the state in which the upper holding section 6a holds the container A2 and stores it in the cargo compartment 3, and Figure 18 shows the state during transfer when the left and right movable arms 74a, 74a protrude from the cargo compartment 3 from that state. Figure 19 shows the state in which the lower holding section 6b holds the container A1 and stores it in the cargo compartment 3, and Figure 20 shows the state during transfer when the left and right movable arms 74b, 74b protrude from the cargo compartment 3 from that state.

[0031] In the autonomous transport vehicle 1 of this embodiment, when a container A is placed in the cargo compartment 3 and held by the holding parts 6 (6a, 6b) in the transfer section 4, the inner holding part 67a of the holding part 6a holds container A1, and the outer holding part 68a of the holding part 6a holds container A2, which is larger than container A1. This allows the vehicle to accommodate various types of containers, even if the shape of the part to be gripped for transport differs depending on the type of container. Therefore, a single autonomous transport vehicle 1 can flexibly transport and transfer multiple types of containers, for example, when transporting or transferring container A2 between transporting or starting to transport or transfer the next container A1 after transferring container A1 would shorten the cycle time of semiconductor manufacturing equipment, thus shortening the cycle time for container exchange. Furthermore, compared to cases where the autonomous transport vehicle is enlarged according to the weight and size of the container in order to transport or transfer a large container such as container A2, the autonomous transport vehicle 1 of this embodiment is based on a vehicle size that can transport or transfer multiple containers A1, and is also capable of transporting or transferring container A2. Therefore, it is possible to accommodate the transfer and transport of multiple types of containers while suppressing the need to enlarge the autonomous transport vehicle.

[0032] Next, an example of the transfer operation of container A by the autonomous transport vehicle 1 will be explained with reference to Figure 21. In this figure, the autonomous transport vehicle 1 is schematically shown by removing the upper panel 31, rear panel 32, left and right side panels 33, 33 and other components of the cargo compartment 3, and by shifting the front-to-back positions of the lifting axes 51, 52 to show different height dimensions, so that the operation of the transfer unit 4 can be seen. In this example, the loading and unloading unit is the loading platform B1 of the load port B. First, Figure (a) shows the state in which the autonomous transport vehicle 1 autonomously transports container A (hereinafter referred to as container A1 before processing) containing semiconductor wafers before processing, holding it in the lower holding unit 6b and housing it in the cargo compartment 3, and has completed fine adjustments by the swivel adjustment unit 25 and left-right adjustment unit 26 so that it can transfer between the loading platform B1 and the cargo compartment B1. At this time, container A1 (hereinafter referred to as processed container A1) containing processed semiconductor wafers is placed on the loading platform B1. Here, an unprocessed semiconductor wafer refers to a wafer that has not been processed in the semiconductor manufacturing process (for example, a wafer that has not undergone the front-end processing of semiconductor manufacturing), while a processed semiconductor wafer refers to a wafer that has undergone processing (including part of the processing) in the semiconductor manufacturing process (for example, a wafer that has undergone the front-end processing). Thus, an unprocessed semiconductor wafer is assumed to be a wafer that has not yet been processed in the semiconductor manufacturing process. Furthermore, in areas where the distinction between front-end and back-end processes becomes blurred, such as when manufacturing advanced packages like chiplets, it is conceivable that not only semiconductor wafers but also semiconductor chips may be handled. Therefore, if the size and shape allow for storage in a container, it is also possible to store semiconductor wafers in container A1 before processing and semiconductor chips in container A1 after processing. In order to accommodate the container A1 on the mounting platform B1 from this state, as shown in Figure (b), the lifting shaft 51 is rotated to lower the upper reciprocating section 7a (arm 72a) to an appropriate height position, the movable arm 74a and the holding section 6a are advanced (protruding from the cargo compartment 3), and the fork section 63a is inserted into the bottom of the container A1 on the mounting platform B1 to hold the container A1.Alternatively, when inserting the fork section 63a to hold container A1, it is also possible to first insert it below the bottom of container A1 (inserting it so that the left and right fork sections 63a sandwich and surround the mounting base B1 in the width direction) and then raise the fork section 63a to hold it. In this case, various shapes of the part A1a to be held of container A can be accommodated. Alternatively, the fork section 63a may be inserted with the extension section 66a slightly open outwards in the width direction, and then the fork section 63a may be moved inwards in the width direction to hold it. In this case, various width dimensions of container A1 can be accommodated, thus increasing the types of containers that can be transferred. Then, as shown in Figure (c), the lifting shaft 51 is rotated to raise the upper arm 72a, and as shown in Figure (d), the movable arm 74a and the holding section 6a are retracted and housed in the cargo compartment 3 together with the processed container A1. Furthermore, as shown in Figure (e), the lifting shaft 51 is rotated to raise the upper arm 72a further along with the processed container A1 and retract it so as not to obstruct the next operation. Simultaneously or immediately after, the lifting shaft 52 is rotated to raise the arm 72b of the lower retractable section 7b to an appropriate height. Next, as shown in Figure (f), the movable arm 74b and the holding section 6b are moved forward together with the container A1 before processing (protruding from the cargo compartment 3) to bring the container A1 along with the fork section 63b slightly above the loading platform B1. From that position, as shown in Figure (g), the lifting shaft 52 is rotated to lower the lower arm 72b to a height where the fork section 63b touches the loading platform B1 and the container A1 before processing is placed on it. Then, as shown in Figure (h), the movable arm 74b and the holding section 6b are retracted and pulled into the cargo compartment 3. Subsequently, the lifting axes 51 and 52 are rotated as needed to lower the forward and backward sections 7a and 7b, and the holding section 6a that holds the processed container A1 and the empty holding section 6b to an appropriate height. The swivel adjustment section 25 and the left / right adjustment section 26 are returned to their original positions where they overlap with the trolley section 21 (the positions before the fine adjustment section 24 fine-tunes the position at which the transfer operation is possible in its own position), and then autonomous travel towards the next loading / unloading section begins.

[0033] In this embodiment, the transfer operation of container A by the autonomous transport vehicle 1 mainly involves two directions of movement: vertical movement by the lifting unit 5 and horizontal movement by the forward / backward unit. Therefore, compared to, for example, transfer using a robot arm, the number of joints and motors in the transfer device 4 is reduced, enabling efficient transfer operation. Furthermore, the number of electrical components (drive units, sensors, etc.) that drive the motors is also reduced, leading to space savings and cost reduction. In addition, the lifting unit 5 is divided into two lifting axes 51 and 52, allowing multiple containers A1 to be lifted and lowered separately. If the sizes of the multiple containers A1 to be transferred and the height of the loading platform B1 of the load port B are known in advance, the lifting axes 51 and 52 can be driven simultaneously to transfer multiple containers A1, leading to a reduction in transfer time.

[0034] <Second embodiment of the transfer unit> In the autonomous transport vehicle 1 according to this embodiment, the second embodiment of the transfer unit (transfer unit 40) is capable of accommodating one or two containers A in the cargo compartment 3, and allows for the simultaneous raising and lowering of two holding units 6a and 6b (each of which may be holding a container A or not (empty)) to transfer them individually. As shown in Figures 22, 23, 24, and 25 (the upper panel 31, rear panel 32, and left and right side panels 33, 33 of the cargo compartment 3 have been removed to make the configuration of the transfer unit 40 easier to see), the transfer unit 40 is configured within a frame structure formed inside the cargo compartment 3, and consists of a lifting unit 50 mainly composed of a single lifting shaft 501, holding units 6 (6a, 6b) that hold two containers A (A1, A2) at different height positions, and two upper and lower moving units 7 (7a, 7b) that move the holding units 6 back and forth between the inside of the cargo compartment 3 and the loading / unloading area such as the load port B outside.

[0035] In the lifting section 50, one lifting shaft 501 is erected in the center of the rear end of the transfer section 4, which is at the back of the cargo compartment 3, and is composed of a ball screw with an external thread that rotates around a vertical axis when driven by a rotary drive unit 501a. The rotary drive unit 501a is located on the lower end side of the lifting shaft 501 and consists of a motor 501b, a gearbox 501c containing a gear that converts the rotation of the motor 501b by 90° and transmits it to the lifting shaft 501, a coupling 501d interposed between the gearbox 501c and the lifting shafts 501 and 52, and a sensor (not shown) that measures the rotational speed and angular velocity of the motor 501b, and precisely controls the rotation of the lifting shaft 501.

[0036] The configuration of the reciprocating sections 7 (7a, 7b) is generally the same as in the first embodiment. At the base end of the reciprocating sections 7 (7a, 7b), there are lifting blocks (not shown) to which movable elements with internal threads screwed into the high position (upper stage) and low position (lower stage) of the lifting shaft 501 are fixed, so as to move up and down by the rotation of the lifting shaft 501. In addition, in the reciprocating sections 7 (7a, 7b), the distance between the reciprocating sections 7a and 7b is fixed to maintain a predetermined distance based on the size of the container A to be transferred. For example, by fixing the distance to maintain a predetermined distance based on the height of the higher of the height of the container A2 held by the holding part 6a of the reciprocating section 7a and the height of the container A1 held by the holding part 6b of the reciprocating section 7b, it is possible to accommodate multiple types of containers. Each lifting block has horizontal bars 71a and 71b fixed in a horizontal position, which are slightly shorter than the distance between the left and right support columns 3d on the rear end side. The configuration from this point onward, namely the left and right pairs of arms 72a (upper fixed arm 73a, movable arm 74a) and 72b (lower fixed arm 73b, movable arm 74b) extending in the front-rear direction, their support structures, drive mechanisms and control, and the configuration, drive mechanisms and control of the holding section 6 (upper holding section 6a, lower holding section 6b), are generally the same as in the first embodiment. Furthermore, the state in which containers A1 and A2 are housed in the cargo compartment 3 and the state when transferring them are also almost the same as in Figures 15 to 20 described in the first embodiment.

[0037] Next, an example of the flow of the transfer operation of container A by the autonomous transport vehicle 1 will be explained with reference to Figure 26. In this figure, similar to Figure 21 explained in the first embodiment, the autonomous transport vehicle 1 is schematically shown by removing the upper panel 31, rear panel 3, left and right side panels 33, 33 and other components of the cargo compartment 3 so that the operation of the transfer unit 40 can be seen. In this example as well, the loading and unloading unit is the loading platform B1 of the load port B. First, Figure (a) shows the state in which the autonomous transport vehicle 1 is autonomously transporting container A1 containing unprocessed semiconductor wafers in the lower holding unit 6b and housed in the cargo compartment 3, and has completed fine adjustments by the swivel adjustment unit 25 and left / right adjustment unit 26 so that a transfer can be performed between it and the loading platform B1 of the load port B. At this time, container A1 containing processed semiconductor wafers is placed on the loading platform B1. To accommodate the container A1 on the loading platform B1 from this state, as shown in Figure (b), the lifting shaft 501 is rotated to simultaneously raise the upper and lower retractable sections 7a and 7b (arms 72a and 72b) to an appropriate height while maintaining a predetermined distance, and the movable arm 74a and holding section 6a are advanced (protruding from the cargo compartment 3) and the fork section 63a is inserted into the bottom of the container A1 on the loading platform B1 to hold it. Then, as shown in Figure (c), the lifting shaft 501 is rotated to simultaneously raise the upper and lower arms 72a and 72b, and as shown in Figure (d), the movable arm 74a and holding section 6a are retracted to accommodate the processed container A1 in the cargo compartment 3. Furthermore, as shown in Figure (e), the lifting shaft 501 is rotated to further raise the upper and lower arms 72a and 72b together with the processed container A1, and at the same time, preparations are made for the next operation, which is to transfer the container A1 before processing. Next, as shown in Figure (f), the movable arm 72b and the holding part 6b are moved forward together with the container A1 before processing (protruding from the cargo compartment 3) to bring the container A1 together with the fork part 63b slightly above the mounting table B1. From that position, as shown in Figure (g), the lifting shaft 501 is rotated to lower the lower arm 72b together with the upper arm 72a to a height where the fork part 63b is in contact with the mounting table B1. Then, as shown in Figure (h), the movable arm 74b and the holding part 6b are retracted and pulled into the cargo compartment 3.Subsequently, the lifting axes 51 and 52 are rotated as needed to lower the forward and backward sections 7a and 7b, and the holding section 6a that holds the processed container A1 and the empty holding section 6b to the appropriate height, and the swivel adjustment section 25 and the left and right adjustment section 26 are returned to their original positions where they overlap with the trolley section 21, and then autonomous travel towards the next loading / unloading section begins.

[0038] In this embodiment, the transfer operation of container A by the autonomous transport vehicle 1, which applies the transfer unit 40 of the second embodiment, is similar to the first embodiment in that there are two directions of movement: the up and down direction by the lifting unit 5 and the forward and backward direction by the reciprocating unit. Therefore, compared to the case of a robot arm, the flow of the transfer operation is simplified and the transfer control is simplified, leading to a reduction in the cycle time for container exchange. Furthermore, the lifting axis of the lifting unit 50 is composed of one lifting axis 501, and by raising and lowering the reciprocating unit 7 while fixing the distance between the reciprocating units 7a and 7b to maintain a predetermined distance based on the size of the container A to be transferred, the container transfer time is longer than in the first embodiment because the lifting and lowering operations of the two arms relative to the lifting axis are simultaneous. However, compared to the case of a robot arm, the positioning control, especially in the up and down direction, can be simplified. In addition, the reciprocating operations of the arm and the holding unit can be performed independently, and since there is only one lifting axis, it leads to space saving and a reduction in manufacturing costs.

[0039] In the embodiment described above, the autonomous transport vehicle 1, which can autonomously travel within a semiconductor manufacturing plant, is designed to accommodate multiple containers A at different heights within the cargo compartment 3. This enables simultaneous transport of multiple containers A. Furthermore, even when transporting only one container A, the lifting and lowering units 5 and 50 and the forward and backward movement unit 4 of the transfer units 4 and 40 can be operated to quickly transfer one or more containers A between the cargo compartment 3 and loading / unloading areas such as the load port B, by utilizing the cargo compartment 3's ability to accommodate multiple containers A at different heights. Additionally, because an autonomously capable mobile robot unit 2 is used, the vehicle can respond more flexibly to changes in the transport route layout than conventional overhead transport devices. Moreover, when increasing the size of containers A to accommodate larger sizes than conventional semiconductor wafers, the structure that allows multiple containers A to be accommodated at different heights within the cargo compartment 3 can be used to minimize the size increase of the autonomous transport vehicle 1.

[0040] In particular, as in the transfer section 4 of the first embodiment, the lifting section 5 is provided with two lifting shafts 51 and 52, and each of them has a forward / backward section 7 (7a and 7b) attached at a different height to enable lifting and lowering operations. Furthermore, each forward / backward section 7a and 7b is composed of retractable arms 72a and 72b, and the containers A are held by holding sections 6a and 6b attached to the tips of each arm 72a and 72b. This configuration makes it possible to independently lift and lower and retract the upper and lower arms 72a and 72b, thereby shortening the time required to transfer the two containers A (especially the positioning time during lifting and lowering operations).

[0041] On the other hand, as in the transfer unit 40 of the second embodiment, a single lifting shaft 501 is provided in the lifting unit 50, and forward and backward sections 7 (7a, 7b) are attached to this lifting shaft 501 at different heights to enable lifting and lowering operations. Furthermore, each forward and backward section 7a, 7b is composed of extendable arms 72a, 72b, and containers A are held by holding sections 6a, 6b attached to the tips of each arm 72a, 72b. As a result, the lifting and lowering operations of the upper and lower arms 72a, 72b are synchronized, but their extension and retraction operations can be made independent. This shortens the time required to transfer the two containers A (especially the positioning time during lifting and lowering operations), reduces the installation space of the transfer unit 40, and reduces the number of parts compared to the case where the transfer unit 4 of the first embodiment is used.

[0042] Furthermore, conventional automated guided vehicles have limitations on the weight they can handle, making it difficult to transport or transfer large containers like container A2. However, the autonomous guided vehicle 1 of this embodiment is configured with fork sections 63a and 63b on the upper and lower holding sections 6a and 6b, making it possible to transfer heavy containers. Moreover, by providing a fork section 63a at the tip of the upper holding section 6a to hold container A in the front-rear and width directions, and by providing an expansion / contraction section 66a that changes the distance between the left and right holding pieces 64a and 65a of the fork section 63a, the autonomous guided vehicle 1 can handle multiple types of containers A1 and A2 with different width dimensions for the held sections A1a and A2a. In particular, the upper fork section 63a is configured to have an inner holding section 67a that holds the containers A1 and A2a from the outside inward according to their width dimensions, an outer holding section 68a that holds them from the inside outward, and upright pieces 64a2 and 65a2 that function as stoppers and are placed between the inner holding section 67a and the outer holding section 68a. As a result, one type of fork section 63a can handle containers A1 and A2 with different width dimensions, corresponding to both the containers A1a held from the outside and the containers A2a held from the inside. Moreover, by using the upright pieces 64a2 and 65a2 as stoppers, the stability of the containers A1 and A2 in the held state can be improved.

[0043] Furthermore, in this embodiment, the traveling robot unit 2 is provided with a swivel adjustment unit 25 and a left / right adjustment unit 26 as a fine adjustment unit 24. This allows the trolley unit 21 to approach the loading / unloading area such as the load port B and stop at a rough position. Then, the swivel adjustment unit 25 is operated to swivel the cargo compartment unit 3 so that it faces the loading / unloading area such as the load port B, and the left / right adjustment unit 26 is operated to align the widthwise centers of the cargo compartment unit 3 and the loading / unloading area such as the load port B. As a result, a state in which container A can be properly transferred can be prepared in a short time without moving the differential two-wheel trolley unit 21.

[0044] It should be noted that the present invention is not limited to the embodiments described above. For example, in the embodiments described above, an example was shown in which the lifting section 5 was fitted with lifting shafts 51, 52, and 501 made of ball screws, and a holding section 6a was exemplified in which ball screws were also fitted to the extension and retraction movements of the arms 72a and 72b, and the expansion and contraction movements of the fork section 63a in the expansion and contraction section 66a, and the operation of these mechanical components was described in detail, but in addition to ball screws, other appropriate drive methods such as linear motors can be used for the operation of each mechanical component.

[0045] Furthermore, although the above-described embodiment described a configuration in which the expandable / contractible part 66a is provided only on the upper holding part 6a, it is also possible to adopt a configuration in which the expandable / contractible part 66a is provided on both the upper and lower holding parts 6a and 6b, or to adopt a fork part without an expandable / contractible part when handling only containers A with a constant width dimension of the part to be transferred.

[0046] Furthermore, in the above-described embodiment, the cargo compartment 3, trolley section 21, swivel adjustment section 25, and left / right adjustment section 26 are shown with their outer perimeters covered by covers to prevent visibility of the interior. However, it is also possible to provide openings in the covers or to adopt a configuration without covers as needed.

[0047] Furthermore, the advantage of providing a fine adjustment unit 24 between the trolley unit 21 and the cargo compartment unit 3 of the mobile robot unit 2 is not limited to autonomous mobile transport vehicle 1 equipped with a differential two-wheel trolley unit 21 as in this embodiment. In other words, in response to the phenomenon where stopping after travel and starting travel after stopping takes time due to the effect of the moment of inertia which increases as the weight of the autonomous mobile transport vehicle 1 itself and the weight of container A increase, it is possible to reduce the moment of inertia by at least the weight of the trolley unit 21, thereby making stopping and starting travel easier. In addition, in the fine adjustment unit 24, the vertical arrangement of the swivel adjustment unit 25 and the left / right adjustment unit 26 may be reversed from that of the embodiment described above.

[0048] Furthermore, the autonomous transport vehicle of the present invention is not limited to transporting containers such as FOUPs and PANEL FOUPs in semiconductor manufacturing plants, but can also be applied as an autonomous transport vehicle used for transporting and transferring goods in general.

[0049] Furthermore, the specific configuration and shape of each part are not limited to the above embodiments, and various modifications are possible without departing from the spirit of the present invention. [Explanation of Symbols]

[0050] 1…Autonomous transport vehicle 2…Road Robot Section 21... Bogie section 24…Fine adjustment section 25... Swivel adjustment section 26…Left and right adjustment section 3…Cargo area 4, 40...Transfer section 5, 50... Lifting section 51, 52, 501... Lifting axes 6(6a, 6b)...Holding part 63a, 63b... Fork section 64a, 65a, 64b...holding piece 64a2, 65a2, 64b2...stopper part (standing piece, hanging piece) 66a…Expansion / contraction part 67a, 67b...inner holding part 68a...Outer holding part 66a…Expansion / contraction part 7…Advance / retreat section 72a, 72b...arm

Claims

1. The system comprises a mobile robot section equipped with an autonomously mobile platform, a cargo compartment section provided on the mobile robot section and capable of accommodating multiple loads in a portion of its internal space, and a transfer section provided within the cargo compartment section for transferring the loads between the cargo compartment section and an external loading / unloading section. An autonomous transport vehicle characterized in that the transfer unit has a plurality of holding units that individually hold the cargo at different height positions, an advance / return unit that moves each of the holding units individually back and forth between the cargo compartment and the loading / unloading unit, and a lifting / lowering unit that moves each of the holding units and each of the advance / return unit up and down within the cargo compartment.

2. The lifting section is provided with two lifting shafts arranged in a vertical position. The autonomous transport vehicle according to claim 1, wherein each of the forward and backward moving parts is configured by an arm that is extendable in the front-rear direction, with the holding part attached to its tip and the base end mounted so as to be able to move up and down along each of the lifting axes.

3. A single lifting shaft is provided in the lifting section, positioned vertically. The autonomous transport vehicle according to claim 1, wherein each of the forward and backward moving parts is composed of two arms that are extendable and retractable in the front-rear direction, with the holding part attached to the tip and the base part mounted so as to be able to move up and down along the lifting axis.

4. The autonomous transport vehicle according to any one of claims 1 to 3, wherein the holding portion comprises a fork portion having a pair of holding pieces that hold a portion to be held set on the load in the front-rear direction and width direction, and an expand / contract portion that can change the distance between the holding pieces.

5. The autonomous transport vehicle according to claim 4, wherein the fork portion is provided with an inner holding portion that holds the load from the outside inward according to the portion of the load to be held, and an outer holding portion that holds the load from the inside outward, and a stopper portion erected between the inner holding portion and the outer holding portion.

6. The autonomous transport vehicle according to claim 1, wherein the traveling robot section is provided with a fine adjustment section mounted on the trolley section for adjusting the transfer position to the loading / unloading section when it is stopped and approaching the loading / unloading section, and the fine adjustment section is configured to include a swivel adjustment section for swiveling the cargo compartment section so that it faces the loading / unloading section directly, and a left-right adjustment section for aligning the widthwise center of the loading / unloading section with the widthwise center of the cargo compartment section.

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