Cart mobility aids

Abstract

To provide a movement assistance device that can manually and easily move an autonomous travel cart.SOLUTION: An movement assistance device 12 is configured to move a cart 1 provided with drive wheels 71 rotatably driven by a drive device, rotatable auxiliary wheels 72, and a frame 103 to which the drive wheels 71 and the auxiliary wheels 72 are attached. The movement assistance device includes a lifting unit 130 configured to lift the cart 1 from the bottom side of the frame 103 to lift up the drive wheels 71 from a travel surface, and wheels 150 allowing the movement assistance device 12 to travel.SELECTED DRAWING: Figure 6

Description

[Technical field]

[0001] The present invention relates to a mobility aid for moving a cart. [Background technology]

[0002] Logistics warehouses are facing chronic labor shortages, which is driving demand for autonomous carts. However, with an autonomous cart, when the drive wheels stop moving due to a malfunction or dead battery, even if you try to move it manually, there is resistance from the drive parts (gears and motors), making it heavier and more difficult to move than if only the free wheels were in use. Therefore, in the unmanned transport vehicle described in Patent Document 1, the drive wheels are lifted off the road surface so that the vehicle can run using only the free wheels. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 08-185225 Summary of the Invention [Problem to be solved by the invention]

[0004] However, providing a drive wheel lifting mechanism for each autonomous cart, as in Patent Document 1, is costly and the mechanism becomes complicated.

[0005] Therefore, an object of the present invention is to provide a mobility assistance device that can easily move an autonomous cart manually. [Means for solving the problem]

[0006] In order to achieve the above-mentioned object, the mobility assistance device for a cart of the present invention is a mobility assistance device for moving a cart which has drive wheels which are rotated by a drive unit, auxiliary wheels which are freely rotatable, and a frame to which the drive wheels and auxiliary wheels are attached, and which has a lifting part which lifts the cart from the bottom side of the frame and raises the drive wheels above the running surface, and wheels which cause the mobility assistance device to run. [Brief description of the drawings]

[0007] [Figure 1] 1 is an external perspective view showing an example of a cart moved by a mobility assistance device according to an embodiment of the present invention. [Diagram 2] FIG. 11 is an external perspective view showing a modified example of the cart. [Diagram 3] FIG. 2 is a functional block diagram showing a configuration of the picking system. [Figure 4] 1A and 1B are external perspective views showing a mobility assistance device according to an embodiment of the present invention, in which (a) is a perspective view seen from the front and left side, and (b) is a perspective view seen from the back and left side. [Diagram 5] 1 is an external perspective view showing a state in which the cart is stored between side ends of the mobility assistance device. FIG. [Figure 6] 1 is an external perspective view showing a state in which the cart is supported by the mobility assistance device. FIG. [Figure 7] 1A is a left side view showing the cart being stored between the side ends of the mobility assistance device, and FIG. 1B is a left side view showing the cart being supported by the mobility assistance device. [Figure 8] FIG. 2 is a conceptual diagram showing an example of a travel path of the cart in the picking system. [Figure 9] 11 is a perspective view showing an example of an internal mechanism of a cart that does not require the above-mentioned mobility assistance device. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] Hereinafter, a mobility assistance device according to an embodiment of the present invention will be described with reference to the drawings. The mobility assistance device according to this embodiment is a dedicated device for moving a cart (autonomous driving cart) that transports merchandise in a picking system that assists in the picking work of merchandise or the like. ●Picking system overview A picking system is a system that drives carts for carrying and transporting products in a warehouse in which many different types of products are stored, and assists in picking work from the warehouse. The picking system manages multiple carts and assigns information on the type and number of products to be picked to the multiple carts. The picking system also transmits information indicating the products to be stored in each cart, i.e., picking work instructions, to a picking worker. The picking system may include an autonomously traveling cart that has an electric drive unit and travels autonomously, and a manual cart that is moved manually by a worker.

[0009] An example of an autonomous cart An example of a cart in which the mobility assistance device according to this embodiment can be used will be described. As shown in Fig. 1, the cart 1 is a device for transporting goods. The cart 1 autonomously travels based on instructions from a control unit 20 mounted on the cart 1 itself or a higher-level device. In the following description, the transport direction of the cart 1 is defined as the +Y direction, the width direction of the cart 1 that is perpendicular to the transport direction is defined as the +X direction, and the vertical direction is defined as the +Z direction. Note that the cart 1A shown in FIG. 2 is another example of a cart that can use a mobility assistance device, but is configured similarly to the cart 1 except that it is provided with a sub-display 51, and may be referred to as appropriate.

[0010] The cart 1 has multiple wheels on its bottom surface, and is a device in the shape of two upper and lower tiers of flat plates connected above the wheels by a support pillar located approximately in the center. A control unit 20 that controls the cart 1 and a battery that supplies power to each functional unit are mounted on the lower part of the support pillar. The cart 1 has multiple weighing units 10 (10a, 10b, 10c, 10d) that weigh products. In this embodiment, the weighing units 10a, 10b are arranged side by side in the front and rear of the cart in the traveling direction on the upper tier, and the weighing units 10c, 10d are arranged in the front and rear of the cart in the traveling direction on the lower tier, sandwiching the control unit 20 between them.

[0011] The cart 1 has a plurality of weighing units 10. In this embodiment, there are four weighing units 10, each capable of weighing independently. The upper surface of the weighing units 10 is flat, and a container is placed on each of them. The container is, for example, a foldable container, so-called a folding container, whose each surface is formed by connecting a plurality of elongated flat plates and hinges. The container is a box-shaped member with an opening at the top, and picked products are stored inside the container. The weighing units 10 weigh the products stored in the container for each container. The weighing units 10 may store the weight of the container in advance, and measure the weight of the products themselves by performing a tare process.

[0012] In the cart 1 according to this embodiment, the weighing units 10 are configured in two levels, upper and lower, with two weighing units 10 provided on each level along the traveling direction, but multiple weighing units 10, for example two, may be provided along the width direction of the cart 1. Also, by placing a container across multiple weighing units 10, it is possible to transport containers with a larger capacity than when one container is placed on each weighing unit 10.

[0013] At the top of the cart 1, at the rear in the direction of travel, there is provided a workbench 110 on which an operator performs various operations on the cart 1. On the workbench 110, mainly arranged are a grip 101 that an operator holds when manually moving the cart 1, a printing mechanism 41 that issues labels to be affixed to containers, a touch panel display 5, a scanner 61 that reads barcodes, a physical button operation unit 7, and the like.

[0014] A printing mechanism 41 shown in Fig. 3 is held on the underside of the work table 110, and the printing mechanism 41 prints on labels pulled out from a label roll. The printed labels are discharged from the side of the cart 1. Note that in a case where an ESL (Electric Shelf Label) is connected to an object to which the label is to be affixed, such as a container, the configuration may not include the printing mechanism 41. In this case, the picking system 100 performs a process to change the display content of the ESL.

[0015] As shown in FIG. 3, the touch panel display 5 has a structure in which a liquid crystal display 5a and a touch panel 5b are stacked on top of each other, and data can be displayed and input on the same surface. The liquid crystal display 5a displays various data. When the operator touches the touch panel 5b, it detects the touched position and accepts input according to the detected position. The liquid crystal display 5a displays information on the product to be picked or the status of the cart 1 to the operator. The scanner 61 can read barcodes on products, shelves in the warehouse, containers, labels, etc. The scanner 61 may include a wireless handheld scanner 61a, as well as a fixed scanner 61b that is fixed above the work table 110 and has a reading area that is a part of the work table 110. The fixed scanner 61b can read barcodes by holding a label issued by the printing mechanism unit 41 downward, for example.

[0016] Drive wheels 71 and a plurality of freely rotatable auxiliary wheels 72 are arranged on the bottom surface of the cart 1. The auxiliary wheels 72 are provided at the front and rear along the traveling direction of the cart 1, and the drive wheels 71 are provided between them. The drive wheels 71 are disposed on the bottom surface of the cart 1, approximately in the center in the traveling direction, below the control unit 20. The drive wheels 71 are arranged in pairs in the width direction, and each is independently driven to rotate by a predetermined drive device. The drive wheels 71 are controlled by the control unit 20 to cause the cart 1 to travel autonomously. The multiple auxiliary wheels 72 are disposed on the periphery of the bottom surface of the cart 1 to support the cart 1 and rotate in association with the movement of the cart 1. In this embodiment, a total of four auxiliary wheels 72 are provided, but the number of auxiliary wheels is not limited as long as they are provided at the front and rear of the driving wheel 71 in the traveling direction.

[0017] The cart 1 also has a rod-shaped sign pole 102. The sign pole 102 is disposed on the left side at the rear in the traveling direction and extends upward. The sign pole 102 can flash in one or more colors, and is an example of an alarm unit that notifies an operator of the state of the cart 1 and the presence or absence of an abnormality.

[0018] Further, a frame 103 is provided below the cart 1, surrounding the entire cart 1 from the outside. The frame 103 is at least integrally configured with the drive wheels 71 via a predetermined member, and when the frame 103 is lifted, the drive wheels 71 are separated from the traveling surface. Further, the frame 103 is exposed at the rear side of the cart 1 so that the mobility assistance device 12 can be inserted, whereas the frame 103 is hidden by a contact sensor 91 at the front side of the cart 1. This makes it easy to find the mounting position of the mobility assistance device 12 when using it, and prevents it from being mounted on the front side of the cart 1 by mistake.

[0019] 1 to 3, non-contact sensors 81, 82 and a contact sensor 91 for detecting at least an object ahead in the traveling direction are disposed in front of the cart 1. Note that the non-contact sensor 82 is not shown in the drawings, but is given a reference number for ease of explanation. The non-contact sensor 81 is a sensor that detects objects in front of and on parts of the sides of the cart 1. The non-contact sensor 81 is configured, for example, by combining a laser range finder and an ultrasonic sensor. With this configuration, even black walls, glass, and mirrors can be detected. The non-contact sensor 81 can be used, for example, to recognize routes that the cart 1 can travel and generate a map of routes that the cart 1 can travel. The non-contact sensor 81 also detects obstacles, people, and the like in front of the cart 1 without contact, and slows down or stops the drive wheels 71 in response to the detection.

[0020] The non-contact sensor 82 is a 2D sensor capable of detecting objects on a plane, and is provided below the bumper incorporating the contact sensor 91. Unlike the non-contact sensor 81, this non-contact sensor 82 is not used for generating a map, but can detect obstacles, people, etc. ahead of the vehicle on a plane at a height close to the traveling surface without contact. This makes it possible to prevent the cart 1 from colliding with an obstacle, etc., or the driving wheels 71 and auxiliary wheels 72 from getting entangled with an obstacle, etc. It is noted that the driving wheels 71 may also be slowed down or stopped depending on the detection result of the non-contact sensor 81.

[0021] The contact sensor 91 is a sensor that is built into the bumper at the front of the cart 1 and detects the contact of the bumper with an object. The contact sensor 91 is, for example, a switch sensor. The driving wheels 71 are stopped in response to detection by the contact sensor 91. The contact sensor 91 can also prevent accidents caused by collisions of the cart 1.

[0022] FIG. 3 is a block diagram showing the configuration of the cart 1. The cart 1 comprises a control unit 20, a weighing unit 10, a printing unit 40, an operation unit 50, a reading unit 60, a driving unit 70, an object detection unit 80, and a collision detection unit 90. The weighing unit 10 comprises a load cell 11 and measures the weight of the product. The printing unit 40 has a printing mechanism unit 41. The printing mechanism unit 41 prints labels and ejects (issues) the printed labels from the label issuing unit. The operation unit 50 is realized by the button operation unit 7 and the touch panel 5b. The reading unit 60 comprises a scanner 61 and reads information such as barcodes.

[0023] The control unit 20 includes a CPU 21, a load cell control unit 22, a print control unit 23, an operation control unit 24, a display control unit 25, a ROM 26, a RAM 27, a reading control unit 28, a drive control unit 29, an object detection control unit 30, a collision detection control unit 31, and a communication processing unit 32. The CPU 21 is mutually connected to each unit included in the control unit 20 via a bus.

[0024] The CPU 21 reads out the control program stored in the ROM 26 and various information stored in the RAM 27, and controls each part based on the read control program and various information. The CPU 21 also stores necessary information in the RAM 27. The ROM 26 stores various information such as various programs executed by the CPU 21. The RAM 27 is a temporary storage area that stores information used by the CPU 21. The RAM 27 is also a storage means that stores various files.

[0025] The CPU 21 also functions as an input control unit that acquires information input to the touch panel 5b and the button operation unit 7 via the operation control unit 24. The touch panel 5b and the button operation unit 7 are each an example of an input unit.

[0026] The CPU 21 also functions as an output control unit that changes the display contents of a screen G1 (described below) displayed on the touch panel 5b. The output control unit is configured to output various information to be communicated to the operator, and may use other methods such as sound instead of or in addition to the above-mentioned configuration of controlling the liquid crystal display 5a to display information. The output control unit may also control the blinking mode of the sign pole 102.

[0027] The load cell control unit 22 controls the load cell 11 provided in the weighing unit 10. The printing control unit 23 controls the printing unit 40. The operation control unit 24 controls the touch panel 5b and the button operation unit 7. The touch panel 5b instructs a desired operation by touching a specific portion of a screen, etc., displayed on the liquid crystal display 5a, as described below. The display control unit 25 controls the liquid crystal display 5a. The reading control unit 28 controls the scanner 61 provided in the reading unit 60. The drive control unit 29 controls the drive wheel 71 provided in the drive unit 70. The object detection control unit 30 controls the non-contact sensors 81, 82 provided in the object detection unit 80. The collision detection control unit 31 controls the contact sensor 91 provided in the collision detection unit 90.

[0028] The communication processing unit 32 is a functional unit that performs wireless communication with an external device. The communication processing unit 32 transmits and receives information to and from the management device 2 through, for example, the network NW. The management device 2 is a higher-level device such as a server or a cloud computer. The communication processing unit 32 receives information such as identification information of the products to be loaded on the cart 1, location information in the warehouse where the products are stored, i.e., information on the lane, shelf, and the row and column on the shelf, and the amount of the products to be loaded. The communication processing unit 32 also receives a travel route planned for the cart 1. Furthermore, the communication processing unit 32 may transmit identification information of the worker inputted via the touch panel 5b to the management device 2. Note that, instead of the configuration in which the management device 2 stores some or all of the above-mentioned information and transmits it to the cart 1, the information may be stored in the control unit 20 of the cart 1.

[0029] Note that the manual cart moved by the worker is configured, for example, with the exception of the drive control unit 29, drive unit 70, and drive wheels 71 from the configuration of the autonomously traveling cart 1 described above, and the other configurations are the same as those of the cart 1. Also, the manual cart may be one in which the drive control unit 29 or drive unit 70 of the autonomously traveling cart 1 is disabled.

[0030] Other examples of autonomous carts The cart 1 described above is just one example, and the mobility assistance device 12 according to this embodiment can be widely used for carts according to other examples. 2 shows a cart 1A according to such another embodiment. This cart 1A is provided with a sub-display 51 at the end of the upper section facing the direction of travel. This sub-display 51 has a display surface disposed on the side facing the direction of travel, and the display surface can be viewed and operated from the side facing the direction of travel. The content that can be viewed and operated on the sub-display 51 can be the same as that of the touch panel display 5.

[0031] As a result, when a worker stands on the side of the cart 1A in the direction of travel and performs work such as loading and unloading products, the worker can check and operate the specified contents on the sub-display 51. Meanwhile, the touch panel display 5 has a display surface facing in the opposite direction to the direction of travel, so that when a worker works on the opposite side to the direction of travel, the worker can check and operate the specified contents on the touch panel display 5. This is convenient because the worker does not have to go around to the touch panel display 5 side or the sub-display 51 side to check and operate the touch panel display 5 or the sub-display 51. In order to improve convenience when an operator works on the side where the sub-display 51 is provided, a scanner 61 may also be provided on the sub-display 51 side.

[0032] ●Configuration of mobility assistance device FIG. 4 shows a mobility assistance device 12 according to this embodiment. The mobility assistance device 12 partially lifts the cart 1 to lift the drive wheels 71 of the cart 1 off the traveling surface, thereby moving the cart 1 when it becomes unable to travel autonomously. The mobility assistance device 12 is composed of a main body 120 that is H-shaped in plan view, a lifting part 130 that lifts the cart 1, a support part 140 that supports the cart 1 by a frame 103, and wheels 150 attached to the main body 120.

[0033] The main body 120 is composed of a pair of side ends 121 that are parallel to each other, and a base portion 122 that connects the pair of side ends 121 . The pair of side ends 121 and the base portion 122 are both rod-shaped members and are made of extruded metal or the like.

[0034] Wheels 150 are attached to the underside of the pair of side ends 121 on both ends in the length direction. The rear of the cart 1 is guided to the inside of one end of the pair of side ends 121. Here, the pair of side ends 121 have a length sufficient to guide the cart 1 so as to sandwich it therebetween, so that the cart 1 guided between the pair of side ends 121 does not slip out in the width direction.

[0035] The base portion 122 is provided at a right angle to the pair of side ends 121, and connects the pair of side ends 121 at a position slightly offset toward the end from the approximate center in the length direction. That is, the side ends 121 are configured with one end on the side where the cart 1 is guided and the other end on the side where the cart 1 is not guided, sandwiching the part where the base portion 122 is connected, and the one end is provided longer than the other end. This makes it easy to know from which side the cart 1 should be guided, and since the length of the side where the cart 1 is guided is long, when the cart 1 is guided inside the side ends 121, the cart 1 is unlikely to come off the mobility assistance device 12 or to rattle. This base portion 122 is a rod-shaped member like the side ends 121, and its length is equal to or slightly longer than the width of the cart 1. This allows the cart 1 to be guided so as to be sandwiched between the pair of side ends 121.

[0036] In this embodiment, the base unit 122 connects the pair of side ends 121 at a position slightly offset toward the end side from the approximate center in the length direction, but in other embodiments, the pair of side ends 121 may be connected at the approximate center in the length direction. As long as the base unit 122 connects the pair of side ends 121 at a position at least closer to the center than the ends of the pair of side ends 121, when the cart 1 is lifted by the lifting unit 130 or supported on the support unit 140, it is possible to prevent the mobility assistance device 12 from losing balance and becoming unstable, such as when the wheel 150 on one end side of the pair of side ends 121 floats off the running surface (so-called wheelie state).

[0037] A lifting portion 130 and a support portion 140 are provided on the upper surface side of the base portion 122 . The lifting part 130 is a member for lifting the cart 1 from the bottom side of the frame 103, and is made of a rectangular thin plate member and is provided approximately in the center of the base part 122. The lifting part 130 is provided on the base part 122 so that its length direction is parallel to the length direction of the side end part 121.

[0038] Lifting portion 130 is bent at a position biased toward one end in the length direction, and is divided into a short side and a long side by the bend. Of these, the short side is inserted into the bottom side of frame 103 of cart 1, and constitutes insertion portion 131 that directly lifts frame 103 from the bottom side. On the other hand, the long side constitutes load application portion 132 that receives a load from the top side and transmits the load to insertion portion 131 using the principle of a lever with the bent portion as a fulcrum. In such a lifting portion 130, the insertion portion 131 and the load applying portion 132 on both ends thereof move up and down in an antipodal manner with the bent portion as a fulcrum.

[0039] When the mobility aid device 12 is attached to the cart 1 from the rear, the insertion part 131 abuts its surface against the bottom surface of the frame 103 to support the frame 103, and its length corresponds to the length of the bottom surface of the abutting frame 103, and its inclination and position are also designed to just abut against the bottom surface of the frame 103. This prevents the mobility aid device 12 from being attached to the front side of the cart 1, where the contact sensor 91 is provided in front, because the insertion part 131 does not reach the bottom surface of the frame 103, and the mobility aid device 12 is attached to the front side of the cart 1 and used incorrectly. Furthermore, an elastic body such as rubber or a spring having an appropriate thickness may be interposed between the load-applying part 132 of the lifting part 130 and the base part 122. This makes it possible to prevent the load-applying part 132 from lowering too much when a load is applied to the load-applying part 132, causing damage to the running surface by contacting the running surface, or the load-applying part 132 from breaking.

[0040] The support parts 140 are parts that support the frame 103 of the cart 1 lifted by the lifting part 130 in a state in which the drive wheels 71 of the cart 1 are lifted above the running surface, and are provided in pair on both sides of the lifting part 130, at both ends of the base part 122. This support portion 140 is composed of a pair of erect portions 141 erected at right angles from the base portion 122, a support surface 142 that connects the upper ends of the pair of erect portions 141 and supports the frame 103, and flanges 143 that extend slightly upward from both side edges of the support surface 142 in the width direction.

[0041] The width of the support surface 142 is slightly larger than the width of the frame 103 it supports, which allows the frame 103 to be supported on the support surface 142 sandwiched between a pair of flanges 143. In addition, because the width of the support surface 142 is not too larger than the width of the frame 103, there is little play, and the cart 1 does not wobble when the mobility assistance device 12 supports the cart 1 and moves the cart 1 together with the mobility assistance device 12. When the frame 103 of the cart 1 is supported on the support surface 142 of the support portion 140 , the movement of the frame 103 is restricted by the flange 143 , and the frame 103 can be prevented from slipping off the support portion 140 .

[0042] The wheels 150 are so-called free rollers, and when the mobility assistance device 12 is moved, they rotate on the travel surface accordingly. In this embodiment, the wheels 150 are free rollers, but in other embodiments, they may be drive wheels that are driven by a predetermined drive device. The wheels 150 may be provided with a locking mechanism for restricting the rotation of the wheels 150. By using the locking mechanism to appropriately lock the wheels 150, for example, when lifting the cart 1 onto the mobility assistance device 12, the mobility assistance device 12 will not move unexpectedly, allowing the user to work safely.

[0043] Examples of using mobility aids An example of how the mobility assistance device 12 can be used will now be described with reference to FIGS. First, as shown in Fig. 5 and Fig. 7(a), the mobility assistance device 12 is prepared on the rear side of the cart 1, and the rear of the cart 1 is placed between the pair of side ends 121. At this time, the rear of the cart 1 is placed between the pair of side ends 121 deep enough that the frame 103 abuts against the base part 122 of the mobility assistance device 12. As a result, the insertion part 131 of the lifting part 130 is inserted so as to slip under the frame 103. In addition, the rear of the cart 1 is fixed between the pair of side ends 121.

[0044] 6 and 7(b), when a worker applies a load to the load application portion 132 by stepping on the load application portion 132, the insertion portion 131 is lifted upward with the bent portion as a fulcrum. As a result, the upper surface side of the insertion portion 131 comes into contact with the bottom surface of the frame 103, and the insertion portion 131 further lifts the frame 103 from the bottom surface side, lifting the drive wheels 71 of the cart 1 off the traveling surface. Furthermore, the frame 103 lifted by the lifting portion 130 slides down the upper surface of the insertion portion 131 which is inclined toward the support portion 140 , and is supported on the support surface 142 of the support portion 140 .

[0045] When a portion of the frame 103 is supported on the support portion 140 of the mobility assistance device 12 and the cart 1 and the mobility assistance device 12 are integrated, the cart 1 abuts the running surface only with the auxiliary wheel 72 on the side in the direction of travel, and the drive wheel 71 and the auxiliary wheel 72 on the rear side are inclined so that they are lifted off the running surface. Here, the frame 103 of the cart 1 is restricted in its movement along the traveling direction of the cart 1 by the flange 143 of the support part 140, and does not slip off the support part 140 even when the cart 1 is moved by the mobility assistance device 12. In addition, the auxiliary wheels 72 on the rear side of the cart 1 are located approximately in the center of the mobility assistance device 12, stabilizing the center of gravity. In this state, the worker can push the cart 1 to move it to a desired location.

[0046] When the cart 1 is to be removed from the mobility assistance device 12 after the cart 1 has been moved to a desired location by the mobility assistance device 12, the frame 103 on the support surface 142 is slightly lifted to overcome the flange 143. This allows the drive wheels 71 and the rear auxiliary wheels 72, which had been floating above the running surface, to come into contact with the running surface again, and the mobility assistance device 12 can be separated from the cart 1. When the cart 1 is to be removed from the mobility assistance device 12 in this manner, if the lifting part 130 is pushed downward, for example by stepping on it, the frame 103 can be lifted with a small force to overcome the flange 143, due to the principle of leverage.

[0047] According to the mobility assistance device 12 of this embodiment, by lifting the rear of the cart 1, the drive wheel 71 located approximately in the center of the cart 1 can be lifted off the running surface, and the cart 1 can be moved by the auxiliary wheel 72 in the direction of travel and the wheels 150 of the mobility assistance device 12. Since providing a mechanism for raising and lowering the drive wheels 71 for each cart 1 is costly, the cart 1 can be freely moved while keeping costs down by using one or more movement assistance devices 12 that can be used with any mechanism of the cart 1.

[0048] In this embodiment, the frame 103 is lifted by the lifting part 130 and supported by the support part 140, but as long as the drive wheels 71 can be lifted, other parts than the frame 103 may be lifted and supported as lifted or supported parts. In addition to the frame 103, the cart 1 may be provided with a part or member that is lifted by the lifting part 130 and supported by the support part 140.

[0049] Overview of cart driving in warehouses As shown in Fig. 8, the warehouse W is roughly divided into a picking area A10, a charging area A1, an orienting container area A2, a picking start area A3, a transport area A4, and a holding area A5. Each area is merely called according to the work content of the cart 1, and does not have to be physically separated. Each area may be physically separated by an opening and closing door, etc.

[0050] The charging area A1 is an area where the battery of the cart 1 is charged. The battery may be chargeable while mounted on the cart 1, or may be removed from the cart 1 and charged. The charging area A1 may be an area where the battery mounted on the cart 1 is replaced with a charged battery. The cart 1 moves from the charging area A1 to the charging area A2.

[0051] The container area A2 is an area where empty containers are loaded onto the cart 1. Empty containers are folded and stacked in the container area A2. A worker in the container area A2 assembles the containers to form them into a shape that can accommodate products, and loads them onto the weighing units 10 of the cart 1. The containers may be loaded onto all the weighing units 10, or may be loaded onto only the weighing units 10 for which loading of products is planned based on the picking plan of the cart 1. In this case, in the container area A2, information on the weighing units 10 for which loading is planned on the cart 1 may be displayed on the liquid crystal display 5a of the cart 1. This information is displayed, for example, by operating the touch panel 5b. In addition, the cart 1 may recognize that the cart 1 is in the container area A2 and display information on the weighing units 10 for which loading is planned, or an operator for prompting the display may be displayed on the touch panel 5b. The cart 1 with the containers loaded moves to the picking start area A3.

[0052] The picking start area A3 is an area defined at the entrance of the picking area A10. The cart 1 starts picking work by passing through the picking start area A3. In a mode in which a picking worker performs picking work while running alongside the cart 1, the picking worker starts running alongside the cart 1 in the picking start area A3. When the picking worker performs login processing using the touch panel 5b or the button operation unit 7, the picking worker and the cart 1 are linked.

[0053] When a picking worker and a cart 1 are linked, a picking plan for the cart 1 may be determined according to the identification information or attributes of the picking worker. After the picker and cart 1 are linked, cart 1 moves to picking area A10.

[0054] The picking area A10 is an area where multiple shelves S that store products to be picked are placed and where pickers perform picking work. The multiple shelves S are placed along the walls of the area or inside the area, and the multiple shelves S define an aisle along which the cart 1 can travel. In other words, the space between the multiple shelves S defines an aisle T along which the cart 1 can travel. Map information that defines the areas within the warehouse W into areas where the cart 1 can travel and areas where it cannot travel is also called a travel map.

[0055] The cart 1 assists the picking work by repeatedly traveling and stopping in the picking area A10 based on data related to a predetermined travel route received from the picking system or input directly. Specifically, the cart 1 autonomously travels to the shelf S on which the product to be picked is stored, and stops near the shelf S. The picking worker identifies the product to be picked by viewing the picking work instructions displayed on the liquid crystal display 5a, and places the specified number of products into the container on the cart 1. When picking is completed, the cart 1 autonomously travels to the shelf S on which the next product to be picked is stored.

[0056] At this time, the picking worker may run alongside the cart 1, or multiple carts 1 may run alongside one picking worker. The number of carts 1 is calculated by the picking system 100 calculating the volume of the products included in the picking plan. With this configuration, one worker can pick multiple carts 1, so a large amount of products can be transported at one time.

[0057] Also, the picker may wait for the cart 1 near the shelf S. In this case, the picker does not need to log in to the cart 1. With this configuration, the picker does not need to run alongside the cart 1, so fatigue is reduced. Also, by arranging many pickers in areas where picking is required frequently and fewer pickers in areas where picking is required less frequently, picking can be performed efficiently with a small number of people. In this manner, it is useful to use the cart 1A having the sub-display 51. That is, when a worker waits at shelf S and the cart 1 approaches, there is a problem that the worker does not know which item to pick up until the cart 1 arrives. In response to this, if the cart 1A displays the shelf number on the sub-display 51 installed facing the direction of travel, the worker waiting for the cart 1A can recognize the product to be picked from the front of the cart 1A by the sub-display 51.

[0058] When the picking work included in the picking work instruction is completed, the cart 1 moves to the transport area A4.

[0059] The transport area A4 is an area where the containers that have been picked are carried out. A conveyor that extends to the outside of the transport area A4 is arranged in the transport area A4. For example, the container is taken off the cart 1 by a transport worker in the transport area A4 and is taken out of the warehouse W via the conveyor. After the container is unloaded, the cart 1 moves to the container area A2. If there is a next job, an instruction to load an empty container is displayed on the cart 1, and the cart waits in the container area A2 to be loaded. If there is no next job, or if the battery capacity of the cart 1 is below a predetermined value, the cart 1 moves to the charging area A1. The predetermined value is, for example, the battery capacity predicted to be used in the next job.

[0060] The fully loaded container may be transported to the transport area A4 by the cart 1 that transported the container during the picking operation, or may be transferred to another cart 1 in the picking area A10, and this cart 1 transports the container to the transport area A4. This configuration is efficient because the fully loaded container is transported to the transport area A4 without waiting for another container loaded on the same cart 1 to become fully loaded. In addition, the cart 1 that transports the container during the picking operation only needs to move to the container area A2 after transferring the loaded container to another cart 1, and does not need to move to the transport area A4. This embodiment is particularly useful when the picking operator waits for the cart 1 near the shelf S.

[0061] The holding area A5 is an area for storing containers when products that meet the plan cannot be picked in the picking area A10. Containers are stored in the holding area A5 when, for example, there is not enough stock of the product to be picked on the shelf S due to a delay in replenishing the shelf S or a shortage, making it impossible to pick the product. When there is at least one container for which picking could not be completed, the cart 1 moves from the picking area A10 to the holding area A5 before moving to the transport area A4. When the shelf S is replenishing with products, the containers stored in the holding area A5 are loaded back onto the cart 1, and the picking operation is performed.

[0062] An example of an autonomous cart that does not require mobility assistance devices In the above-described cart 1, when the cart 1 becomes unable to travel autonomously, the mobility assistance device 12 lifts the drive wheels 71 of the cart 1 off the traveling surface and moves the cart 1 together with the mobility assistance device 12. Meanwhile, in another example, the cart 1 itself can be provided with a mechanism for lifting the drive wheels 71 off the traveling surface and lowering them onto the traveling surface, so that the cart 1 can be moved manually.

[0063] FIG. 9 shows a cart 1B as an example of such an autonomous cart. For ease of explanation of the mechanism (lifting mechanism 160 described later) that lifts the drive wheels 71 above the running surface, FIG. 9 shows the internal mechanism of cart 1B. In addition to this, cart 1B also appropriately includes the workbench 110, printing mechanism 41, touch panel display 5, scanner 61, etc. that are provided on the cart 1 described above.

[0064] The cart 1B is provided with a lifting mechanism 160 for lifting the drive wheels 71 off the running surface and lowering them onto the running surface. The lifting mechanism 160 is composed of an operating lever 161 , a driven part 162 , a protruding part 163 , and a protruding roller 164 . The operating lever 161 is provided at one end in the longitudinal direction of the driven part 162. This operating lever 161 can be pulled outward or pushed inward along the longitudinal direction of the driven part 162, and the driven part 162 is displaced in the longitudinal direction accordingly.

[0065] The follower 162 is a rod-shaped member having a length in the width direction of the cart 1B, and a pair of protrusions 163 are provided on the upper surface side of both ends thereof. Each of the pair of protrusions 163 has a trapezoidal shape with the upper surface side as the upper base, and the portions corresponding to the legs of the trapezoid form inclined surfaces.

[0066] The protruding roller 164 is a freely rotatable member attached to the member to which the drive wheel 71 is attached, or to a specific member attached to the member. When the protruding roller 164 is lifted upward, the drive wheel 71 is lifted up from the traveling surface in conjunction with the protruding roller 164. Moreover, the protruding roller 164 is provided to protrude above the driven portion 162, and is lifted upward by the protruding portion 163 when the driven portion 162 is displaced in its length direction.

[0067] 9(a) shows a state in which the drive wheel 71 is in contact with the traveling surface. At this time, the operating lever 161 is pressed into the inside of the cart 1B, and the protruding roller 164 and the protruding portion 163 are separated from each other. 9(b), when the operating lever 161 is pulled outward from this state, the driven part 162 moves outward in conjunction with this. At this time, the protruding roller 164 comes into contact with the protruding part 163, and then rotates while being guided by the inclined surface of the protruding part 163, and is lifted above the protruding part 163. The driving wheel 71 moves away from the traveling surface in conjunction with the protruding roller 164 being lifted upward.

[0068] When the operating lever 161 is fully pulled outward, the protruding rollers 164 are supported on the upper surface of the protrusion 163, and the driving wheels 71 are not supported on the running surface unless the operating lever 161 is pushed in to lower the protruding rollers 164 from the upper surface of the protrusion 163. In this state, only the four auxiliary wheels 72 of the cart 1B are in contact with the running surface, and the cart 1b can be easily moved manually.

[0069] In this way, by appropriately operating the operating lever 161, the operator can make the cart 1B move autonomously by bringing the drive wheels 71 into contact with the running surface, or can lift the drive wheels 71 off the running surface to easily move the cart 1B manually.

[0070] Another example of an autonomous cart that does not require mobility assistance devices The cart 1B described above is provided with a manually operable lifting mechanism 160 that allows the drive wheels 71 to be raised and lowered, but the lifting mechanism that raises and lowers the drive wheels 71 may be controlled by a drive device such as a drive power source. That is, a cart according to another example (for ease of explanation, referred to as "cart 1C") is provided with a control unit that controls the drive wheels 71, and a lifting mechanism that raises and lowers the drive wheels 71 in response to control by the control unit, and when a predetermined operation is performed from the touch panel display 5 or a separately provided operation button, the lifting mechanism is controlled by the control unit and the drive wheels 71 are raised and lowered. Regarding the control of the lifting mechanism, a backup or emergency drive device may be provided that is different from the drive device of the drive wheels 71. This allows the lifting mechanism to be controlled even if the drive device that drives the drive wheels 71 breaks down or the battery runs out.

[0071] In such a cart 1C, when the cart 1C reaches a predetermined state, the control unit may control the lifting mechanism to lift and lower the drive wheels 71. Here, the specified state is, for example, a state in which the cart is unable to move due to a malfunction, a state in which the battery is depleted and the drive wheels 71 cannot be driven, or a state in which the cart 1C has lost track of its own position within the warehouse, requiring an operator to manually push the picking cart.

[0072] Also, depending on the work status and work data of the cart 1C, the control unit may control the lifting mechanism to lift and lower the drive wheels 71. For example, when a worker works with the cart 1C, the control unit determines whether the cart 1C is to be used as an autonomous cart that drives the drive wheels 71, or whether it is to be treated as a manual cart that moves only with the free auxiliary wheels 72, and then lifts and lowers the drive wheels 71.

[0073] More specifically, when performing work, a guide as to whether to perform the work in a self-propelled manner or manually is displayed on the touch panel display 5. The worker decides in which manner to perform the work depending on the work situation and the work data when the work data and the cart 1C are linked. Here, the work status and work data include the weight of the picked product, the distance traveled, the details of the work, and the like.

[0074] In terms of the weight of the products to be picked, if it is known that the total weight of the four containers to be picked will be large, or if heavy containers are collected and combined on cart 1C, the lifting mechanism is controlled to lower drive wheels 71 to the running surface so that cart 1C can be used as an autonomous cart. Conversely, if it is known that the containers contain light products, or if light products are combined in total weight, the lifting mechanism is controlled to raise drive wheels 71 above the running surface so that cart 1C can be used manually.

[0075] In terms of travel distance, in order to avoid a situation where a worker has to walk around the warehouse to perform picking work, the travel distance is calculated from the work data, and if the travel distance is greater than a specified distance, cart 1C is used as an autonomous cart, and if the distance is shorter, it is used as a manual cart, and the drive wheels 71 are raised and lowered according to each situation. From the viewpoint of the content of the work, when the work data shows that the number of processes for that day is high (when it looks like it will be high), the number of carts 1C operated as autonomous carts is increased. Also, when the work data shows that the number of workers for that day is low (when it looks like it will be low), the number of carts 1C operated as autonomous carts is increased.

[0076] As a result, in a work site where picking work is performed by switching one cart 1C between self-propelled and manual modes, it is possible to use either mode depending on the work situation and work data.

[0077] <Additional Notes> The autonomous cart is A first wheel (drive wheel 71) provided at the bottom of the autonomous cart and driven by a drive device (which automatically travels to a predetermined position based on the travel route received by the picking cart); A second wheel (auxiliary wheel 72) that is freely rotatable and provided on the bottom of the autonomous cart; and a lifting mechanism for lifting or lowering the first wheel. It is characterized by:

[0078] A control unit for controlling the lifting mechanism is further provided. When the autonomous cart reaches a predetermined state, the control unit causes the lifting mechanism to lift the first wheel. It may also be possible to use the same method.

[0079] The autonomous cart is A first display unit (touch panel display 5) that displays instructions for a picking operation of an item (goods) and accepts operations; A second display unit (sub-display 51) that displays instructions for the item picking operation, the first display unit has a display surface arranged opposite to a traveling direction of the autonomous driving cart, The second display unit has a display surface arranged in the traveling direction of the autonomous driving cart. It is characterized by:

[0080] Summary of the implementation form The present invention relates to a mobility aid for moving a cart.

[0081] Logistics warehouses are facing chronic labor shortages, which is driving demand for autonomous carts. However, with an autonomous cart, when the drive wheels stop moving due to a malfunction or dead battery, even if you try to move it manually, there is resistance from the drive parts (gears and motors), making it heavier and more difficult to move than if only the free wheels were in use. Therefore, in the unmanned transport vehicle described in JP-A-08-185225, the drive wheels are lifted off the road surface so that the vehicle can run on the free wheels alone.

[0082] However, providing a drive wheel lifting mechanism for each autonomous cart, as in the unmanned transport vehicle described in JP-A-08-185225, is costly and the mechanism becomes complicated.

[0083] Therefore, an object of the present invention is to provide a mobility assistance device that can easily move an autonomous cart manually.

[0084] In order to achieve the above-mentioned object, the mobility assistance device for a cart of the present invention is a mobility assistance device for moving a cart which has drive wheels which are rotated by a drive unit, auxiliary wheels which are freely rotatable, and a frame to which the drive wheels and auxiliary wheels are attached, and which has a lifting part which lifts the cart from the bottom side of the frame and raises the drive wheels above the running surface, and wheels which cause the mobility assistance device to run.

[0085] The vehicle may further include a support portion that supports the frame lifted by the lifting portion in a state in which the drive wheels are lifted above a traveling surface.

[0086] The support portion may include a support surface that supports the frame, and flanges that extend upward from both side edges in a width direction of the support surface.

[0087] The device may further include a base portion on which the lifting portion and the support portion are provided, and a pair of rod-shaped side ends which are equipped with the wheels and are connected to the base portion at right angles and guide the cart inwardly, and the side ends are composed of one end portion on the side where the cart is guided and the other end portion on the side where the cart is not guided, sandwiched between the point where the base portion is connected, and the one end portion may be longer than the other end portion.

[0088] The lifting portion may be provided substantially in the center of the base portion, and the support portions may be provided on both sides of the lifting portion.

[0089] With the mobility assistance device of the present invention, by lifting the rear of the cart, the drive wheels located approximately in the center of the cart can be raised off the running surface, and the cart can be moved using the auxiliary wheels in the direction of travel and the wheels of the mobility assistance device. Since providing a mechanism for raising and lowering the drive wheels for each cart would be costly, by using one or more mobility assistance devices that can be used with carts equipped with any mechanism, costs can be reduced and the carts can be moved freely. [Explanation of symbols]

[0090] 1: Cart 5: Touch panel display 7: Button operation section 10: Weighing Department 51: Sub-display 60: Reading unit 61: Scanner 71: Drive wheel 72: Training wheels 81: Non-contact sensor 91: Contact sensor 101: Grip 102: Signpost 103: Frame 110: Workbench 12: Mobility aids 120: Main unit 121: Side edge 122: Base part 130: Lifting part 131: Insertion part 132: Load application section 140: Support part 141: Vertical section 142: Support surface 143: Flange 150 :Wheel 160: Lifting mechanism 161: Operating lever 162: Driven part 163:Protrusion 164: Protruding roller

Claims

[Claim 1] A mobility assistance device for moving a cart including a drive wheel that is rotationally driven by a drive device, a freely rotatable auxiliary wheel, and a frame to which the drive wheel and the auxiliary wheel are attached, comprising: a thin-plate-shaped lifting portion that lifts the cart from the bottom side of the frame and lifts the drive wheels off the running surface; a support portion that supports the frame lifted by the lifting portion in a state in which the drive wheels are lifted off the traveling surface; and wheels for propelling the mobility assistance device; The lifting portion is One side in the length direction constitutes an insertion part that is inserted into the bottom surface side of the frame of the cart, and the other side in the length direction constitutes a load application part to which a load is applied from the top surface side, and the insertion part and the load application part move up and down antipodally with the position where the insertion part and the load application part are connected as a fulcrum. Cart mobility aid.

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