forklift

Abstract

To transport a loaded article more safely.SOLUTION: This forklift comprises: a traveling vehicle body; a fork; a sensor; and a determination unit. The fork is provided in the front of the traveling vehicle body, and has a recess formed at the tip. The sensor is stored in the recess, and detects a state around the tip. The determination unit determines whether the tip of the fork is out of a fork insertion hole provided in a pallet on the basis of the sensing result of the sensor.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The disclosed embodiments relate to a forklift. [Background Art]

[0002] Conventionally, in forklifts, a technology has been proposed for automatically controlling the forks by capturing images of the tip side of the forks with a camera provided at the base end of the forks (see, for example, Patent Document 1). [Prior Art Documents] [Patent Documents]

[0003] [Patent Document 1] Japanese Unexamined Patent Publication No. 2022-17613 [Summary of the Invention] [Problem to be Solved by the Invention]

[0004] In order to safely transport a load placed on a pallet using a forklift, it is important that the forks are properly inserted into the fork insertion holes of the pallet.

[0005] However, in the conventional technology as described above, since an image of the tip side of the fork is captured from the base end side of the fork, it is difficult to check whether the fork is properly inserted into the fork insertion hole.

[0006] The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a forklift capable of transporting loads more safely. [Means for Solving the Problem]

[0007] A forklift according to one embodiment comprises a vehicle body, forks, a sensor, and a determination unit. The forks are provided at the front of the vehicle body and have a recess formed at their tip. The sensor is housed in the recess and detects the conditions around the tip. Based on the sensing result of the sensor, the determination unit determines whether the tip of the fork is protruding from a fork insertion hole provided in the pallet. [Effects of the Invention]

[0008] According to one embodiment, the load can be transported more safely. [Brief explanation of the drawing]

[0009] [Figure 1] Figure 1 shows an overview of a forklift according to the first embodiment. [Figure 2] Figure 2 shows an example of the installation of the situation detection sensor according to the first embodiment. [Figure 3] Figure 3 is a block diagram showing an example of the functional configuration of a control device according to the first embodiment. [Figure 4] Figure 4 is a block diagram showing an example of the functional configuration of a weight detection device according to the first embodiment. [Figure 5] Figure 5 is a diagram showing an example of linked information according to the first embodiment. [Figure 6] Figure 6 shows an example of detecting the condition of the fork tip according to the first embodiment. [Figure 7] Figure 7 shows another example of fork tip condition detection according to the first embodiment. [Figure 8] Figure 8 is a flowchart showing an example of the procedure for processing performed by the control device according to the first embodiment. [Figure 9] Figure 9 is a flowchart showing an example of the procedure performed by the weight detection device according to the first embodiment. [Figure 10] Figure 10 is a schematic side view of a forklift according to the second embodiment. [Figure 11]FIG. 11 is a diagram showing a configuration example of a window according to the first embodiment. [Figure 12] FIG. 12 is a diagram schematically showing an example of a hardware configuration of a computer that functions as a control device and / or a weight detection device. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, the present invention will be described through embodiments. However, the following embodiments do not limit the invention according to the claims. Furthermore, not all combinations of features described in the embodiments are necessarily essential to the solution of the invention.

[0011] <First Embodiment> [Outline of Forklift 1] FIG. 1 is a diagram showing an outline of the forklift 1 according to the first embodiment. In FIG. 1, side views of the forklift 1 and a flat pallet P (hereinafter, also simply referred to as a pallet P) are shown. The forklift 1 illustrated in FIG. 1 is a schematic diagram, and some configurations are omitted for convenience of explanation.

[0012] The forklift 1 shown in the present disclosure travels by automatic control. That is, the forklift 1 shown in the present disclosure transports a load L by unmanned automatic traveling.

[0013] Note that the forklift 1 is not limited to being an unmanned vehicle, and may be configured to be manually driven by a manned operator. Alternatively, the forklift 1 may be configured to be switchable between an unmanned mode and a manned mode.

[0014] Hereinafter, for convenience of explanation, an orthogonal XYZ coordinate system may be shown in the drawings. The traveling direction of the forklift 1 corresponds to the X direction. A direction perpendicular to the ground corresponds to the Y direction. The lateral direction of the forklift 1 corresponds to the Z direction.

[0015] As shown in Figure 1, the forklift 1 includes a traveling vehicle body 2, forks 3, a lifting part 4, a situation detection sensor 5 (an example of a sensor), a load sensor 6, a control device 10, and a weight detection device 20.

[0016] (Traveling vehicle body 2) The traveling vehicle body 2 is a vehicle body that travels on a road surface R such as in a warehouse. The traveling vehicle body 2 travels on the road surface R by, for example, driving wheels in contact with the road surface R.

[0017] (Forks 3) The forks 3 are members on which a pallet P with a load L placed thereon is mounted. A plurality of forks 3 are provided on one traveling vehicle body 2. The forks 3 are configured, for example, as a pair of left and right (that is, two members). By being inserted into a fork insertion hole 7 provided in the pallet P and lifted, the forks 3 carry the pallet P and the load L placed on the pallet P.

[0018] (Lifting part 4) The lifting part 4 lifts and lowers the forks 3 in accordance with control from the control device 10. Thereby, the height position of the forks 3 is changed. By changing the height of the forks 3 via the lifting part 4, the forklift 1 inserts the forks 3 into the pallet P, and carries the pallet P placed on the forks 3 and the load L.

[0019] (Situation detection sensor 5) The situation detection sensor 5 is a sensor that detects the situation around the tip end portions of the forks 3. The situation detection sensor 5 is provided at the tip end portions of the forks 3. The situation detection sensor 5 is, for example, a camera, Lidar (Light Detection And Ranging), a radar device, or the like. The situation detection sensor 5 may include a plurality of sensors such as a camera and Lidar.

[0020] (Load sensor 6) The load sensor 6 is a sensor that detects the load applied to the fork 3. The load sensor 6 is installed, for example, at the base end of the fork 3. When a pallet P and a load L are placed on the fork 3, the load sensor 6 detects the total weight of the pallet P and the load L as the load.

[0021] (Control device 10) The control device 10 controls the entire forklift 1. For example, the control device 10 controls the wheels of the vehicle body 2 to control the automatic movement of the forklift 1 on the road surface R. The control device 10 also controls the lifting unit 4 to control the automatic raising and lowering of the forks 3. The control device 10 acquires the sensing results from the situation detection sensor 5 and controls the situation detection sensor 5. The detailed configuration and processing of the control device 10 will be described later.

[0022] (Weight detection device 20) The weight detection device 20 detects the weight of the pallet P and the load L placed on the fork 3. The weight detection device 20 detects at least one of the following: the weight of the pallet P, the weight of the load L, the weight of the outer packaging of the load L, and the weight of the contents of the load L. The method of weight detection by the weight detection device 20 will be described later.

[0023] [Example of installation of the status detection sensor 5] Figure 2 shows an example of the installation of the situation detection sensor 5 according to the first embodiment. Figure 2 shows the fork 3 viewed from the tip side toward the base side (viewed from the negative X-axis direction).

[0024] As shown in Figure 2, the fork 3 has a recess 3a at its tip. The situation detection sensor 5 is positioned to be housed in the recess 3a. For example, the recess 3a of the fork 3 has a recessed shape on the road surface R side (negative Y-axis direction side) where the vehicle body 2 travels.

[0025] In other words, the situation detection sensor 5 is installed on the road surface R side of the fork 3. The situation detection sensor 5 senses the situation on at least one of the following sides: the road surface R side (negative Y-axis direction) and the front side of the forklift 1 (negative X-axis direction).

[0026] In this way, by being housed in the recess 3a that is recessed on the road surface R side, the situation detection sensor 5 can detect the surrounding conditions without coming into contact with the pallet P, even when the pallet P is placed on the fork 3.

[0027] Furthermore, as shown in Figure 2, the depth of the recess 3a (length in the Y-axis direction) is greater than the height of the situation detection sensor 5 (length in the Y-axis direction). In other words, the tip of the recess 3a on the road surface R side is closer to the road surface R than the tip of the situation detection sensor 5 on the road surface R side. As a result, even if an object comes into contact with the fork 3 from the road surface R side, the situation detection sensor 5 can avoid coming into contact with this object.

[0028] Furthermore, as shown in Figure 1, the tip of the fork 3 is positioned in front of the situation detection sensor 5 (towards the negative X-axis direction). This ensures that even if an object makes contact with the tip of the fork 3, the situation detection sensor 5 will not come into contact with that object.

[0029] By positioning the situation detection sensor 5 at the tip of the fork 3, the detection results of the situation detection sensor 5 do not include information about the fork 3. For example, if the situation detection sensor 5 is a camera, the fork 3 will not be visible in the captured image. This allows the forklift 1 to more accurately understand the situation at the tip of the fork 3.

[0030] As a result, even if, for example, the pallet P is placed at a high position (for example, in manned mode where the operator is operating the forklift 1, at a position higher than the operator's eye level), the forklift 1 can accurately insert the forks 3 into the insertion openings of the pallet P.

[0031] [Detailed example of control device 10] Figure 3 is a block diagram showing an example of the functional configuration of the control device 10 according to the first embodiment. As shown in Figure 3, the control device 10 comprises a communication unit 11, a storage unit 12, and a control unit 13.

[0032] (Communications Section 11) The communication unit 11 is implemented, for example, by a NIC (Network Interface Card). The communication unit 11 connects to the network, for example, wirelessly. For example, the communication unit 11 is connected to a server device (not shown) that manages the forklift 1 in a communicative manner.

[0033] (Storage unit 12) The memory unit 12 stores programs and data used for control and calculations by the control unit 13. The memory unit 12 is implemented by, for example, semiconductor memory elements such as RAM (Random Access Memory) and flash memory, or by storage devices such as hard disks and optical discs.

[0034] (Control Unit 13) The control unit 13 is a controller that performs control and calculations for the control device 10. Each part of the control unit 13 is realized by various programs stored in the internal memory of the control device 10 being executed using RAM as the working area by a CPU (Central Processing Unit) or MPU (Micro Processing Unit), for example.

[0035] Furthermore, the control unit 13 is implemented by an integrated circuit such as an ASIC (Application Specific Integrated Circuit), FPGA (Field Programmable Gate Array), or SoC (System on a Chip).

[0036] As shown in Figure 3, the control unit 13 includes a detection unit 131 (an example of a determination unit) and an operation control unit 132. The control unit 13 realizes or executes the functions and operations of the processes described below through the parts shown in Figure 3. For example, the control unit 13 automatically controls the vehicle body 2 and the fork 3 (lifting unit 4) based on the information detected by the situation detection sensor 5.

[0037] Although not explained here, the internal configuration of the control unit 13 is not limited to the parts shown in Figure 3, and may include parts that realize or execute functions and operations for automatic driving and transporting the cargo L.

[0038] (Detection unit 131) The detection unit 131 detects the surrounding conditions around the tip of the fork 3 based on the information (sensing results) detected by the situation detection sensor 5. For example, the detection unit 131 detects the surrounding conditions from captured images taken by a camera, Lidar, and target information (position information and shape information) detected by a radar device, etc.

[0039] The detection unit 131 detects pallets P (see Figures 6 and 7) present around the forklift 1 based on the captured image and target information. For example, the detection unit 131 detects the number and position of pallets P based on pattern matching using the captured image or shape information in the target information.

[0040] The detection unit 131 detects the position of the tip of the fork 3 in the fork insertion hole 7 (see Figure 1) of the pallet P based on the captured image and target information. Based on the sensing results of the situation detection sensor 5, the detection unit 131 determines whether or not the tip of the fork 3 is protruding from the fork insertion hole 7 of the pallet P. In this way, the detection unit 131 performs situation detection of the tip of the fork 3. Details of this situation detection will be described later.

[0041] The detection unit 131 determines whether or not there is a load L on the detected pallet P. For example, the detection unit 131 determines whether or not there is a load L on each pallet P based on pattern matching using the captured image or shape information in the target information.

[0042] (Operation control unit 132) The motion control unit 132 automatically controls the vehicle body 2 and the forks 3 based on the information detected by the detection unit 131. For example, the motion control unit 132 identifies the pallet P on which the load L is placed that is closest to the forklift 1. The motion control unit 132 then automatically controls the identified pallet P as the target for transport.

[0043] Furthermore, the pallet P to be transported is not limited to the pallet P closest to the forklift 1, but may also be a pallet P located in a specific area.

[0044] The motion control unit 132 identifies the orientation of the pallet P to be transported and controls the vehicle body 2 to move to a position where the forklift 1 is facing the front of the pallet P.

[0045] For example, if the pallet P is rectangular when viewed from above (from the positive Y-axis direction), the motion control unit 132 identifies one of the four sides constituting the rectangle as the front of the pallet P.

[0046] Next, the motion control unit 132 moves the forklift 1 to the front of the pallet P. After that, the motion control unit 132 identifies the position of the fork insertion holes 7 (see Figure 1) of the pallet P. For example, the motion control unit 132 identifies the position of the fork insertion holes 7 based on the image captured by the detection unit 131 and the shape information of the target (pallet P).

[0047] The motion control unit 132 controls the lifting unit 4 to adjust the height of the fork 3 to the position of the identified fork insertion hole 7. Then, the motion control unit 132 controls the vehicle body 2 to insert the fork 3 into the fork insertion hole 7.

[0048] The motion control unit 132 inserts the fork 3 into the fork insertion hole 7 until the detection unit 131 detects that the tip of the fork 3 has emerged from the fork insertion hole 7. After that, the motion control unit 132 controls the lifting unit 4 to raise the fork 3 and lift the pallet P.

[0049] The motion control unit 132 then automatically calculates the route (for example, the shortest distance route) to the target position where the pallet P will be placed. The motion control unit 132 then controls the vehicle body 2 to move along the route to the target position.

[0050] After arriving at the target position, the motion control unit 132 controls the lifting unit 4 to place the pallet P at the target position. Then, after placing the pallet P, the motion control unit 132 identifies the next pallet P to be transported. In this way, the motion control unit 132 controls the forklift 1 to transport the load L sequentially.

[0051] [Detailed example of weight detection device 20] Figure 4 is a block diagram showing an example of the functional configuration of the weight detection device 20 according to the first embodiment. As shown in Figure 4, the weight detection device 20 comprises a communication unit 21, a storage unit 22, and a control unit 23.

[0052] (Communications Section 21) The communication unit 21 is implemented, for example, by a NIC (Network Interface Card). The communication unit 21 connects to a network, for example, wirelessly. For example, the communication unit 21 is connected to a server device (not shown) that manages the forklift 1 in a communicative manner. Note that the communication unit 11 (see Figure 3) and the communication unit 21 may be a single communication unit shared by the control device 10 and the weight detection device 20.

[0053] (Storage unit 22) The storage unit 22 shown in Figure 4 stores programs and data used for control and calculations by the control unit 23. The storage unit 22 can be implemented using, for example, semiconductor memory elements such as RAM or flash memory, or storage devices such as hard disks or optical discs. Note that the storage unit 12 (see Figure 3) and the storage unit 22 may be a single storage unit shared by the control device 10 and the weight detection device 20.

[0054] The memory unit 22 stores the association information 221. The association information 221 is information generated by the control unit 23, which will be described later.

[0055] Figure 5 is a diagram showing an example of the linked information 221 according to the first embodiment. As shown in Figure 5, the linked information 221 includes "pallet ID", "category", "item", "quantity", and "weight".

[0056] "Pallet ID" is identification information that identifies pallet P. "Category" is information indicating the type of outer packaging in the load L. "Item" is information indicating the item of contents of load L. "Quantity" is information indicating the quantity of load L. "Weight" is information indicating the weight of the contents.

[0057] (Control Unit 23) Returning to Figure 4, the control unit 23 is a controller that performs control and calculations for the weight detection device 20. Each part of the control unit 23 is realized by various programs stored in the internal memory of the control device 10 being executed by a CPU or MPU, for example, using RAM as the working area.

[0058] Furthermore, the control unit 23 is implemented by an integrated circuit such as an ASIC, FPGA, or SoC.

[0059] As shown in Figure 4, the control unit 23 includes a detection unit 231, a specification unit 232, an estimation unit 233, and a memory processing unit 234. The control unit 23 realizes or executes the functions and operations of the processes described below through the parts shown in Figure 4. For example, the control unit 23 detects information about the load L based on information detected by the situation detection sensor 5 and the load sensor 6.

[0060] Although not explained here, the internal configuration of the control unit 23 is not limited to the parts shown in Figure 4, and may include parts that realize or execute the functions and operations for processing information about the loaded object L.

[0061] The control unit 23 detects the external appearance information of the load L placed on the pallet P into which the fork 3 is inserted. Based on the detected external appearance information, the control unit 23 identifies the outer packaging other than the contents of the load L. Based on the identified outer packaging, the control unit 23 estimates the weight of the contents of the load L. This allows the control unit 23 to detect the weight of the contents of the load L from the weight of the outer packaging (e.g., cardboard box, etc.) containing the contents.

[0062] (Detection unit 231) The detection unit 231 detects the appearance information of the load L placed on the pallet P inserted into the fork 3. For example, the detection unit 231 detects the image captured by the camera, which is the situation detection sensor 5, and the shape information of the target detected by the Lidar and radar devices, which are also the situation detection sensors 5, as appearance information.

[0063] Furthermore, the detection unit 231 detects (acquires) the load applied to the fork 3 when the fork 3 lifts the pallet P from the load sensor 6. In other words, the detection unit 231 detects the load from the load sensor 6 as the total weight of the pallet P and the load L.

[0064] Furthermore, the detection unit 231 detects the weight of the pallet P. For example, the detection unit 231 detects the weight of the pallet P by detecting the weight information written on the pallet P using a situation detection sensor 5 such as a camera. The weight information is, for example, code information in which the weight information of the pallet P is embedded. The code information is a two-dimensional code or a barcode. In addition to code information, the weight information may also be information in which the weight of the pallet P is printed directly on the pallet P.

[0065] Furthermore, information other than weight information may be inscribed on pallet P. For example, pallet information such as the color and shape of pallet P may be inscribed using code information or the like.

[0066] (Specific Section 232) The identification unit 232 identifies outer packaging other than the contents of the load L based on the visual information detected by the detection unit 231. For example, the identification unit 232 identifies outer packaging based on the captured image and the shape information of the target. Outer packaging is a component that contains the contents. Examples of outer packaging include cardboard, wrapping paper, packaging materials, boxes, cases, etc. The identification unit 232 also identifies the category of the identified outer packaging (material such as cardboard).

[0067] Furthermore, the identification unit 232 identifies cargo information related to the cargo L based on the external appearance information. Cargo information includes, for example, information about the items of contents and the quantity of cargo L (number of cardboard boxes, etc.).

[0068] For example, the identification unit 232 identifies the cargo information based on the captured image and the shape information of the target. The items of the cargo L can be identified, for example, based on information printed on the cardboard box which is the outer packaging.

[0069] (Estimation Department 233) The estimation unit 233 estimates the weight of the contents based on the identified outer packaging. First, the estimation unit 233 estimates the weight of the identified outer packaging. For example, the estimation unit 233 estimates the weight of the outer packaging based on its size, material, etc.

[0070] The estimation unit 233 then estimates the weight of the contents based on the estimated weight of the outer packaging and the load detected by the load sensor 6. More specifically, the estimation unit 233 estimates the weight of the contents by subtracting the weight of the pallet P and the weight of the outer packaging from the load detected by the load sensor 6.

[0071] In other words, the estimation unit 233 estimates the weight of the contents as the weight obtained by subtracting the weight of the pallet P and the weight of the outer packaging from the load (the total weight of the pallet P and the contents L).

[0072] (Memory processing unit 234) The memory processing unit 234 links the cargo information identified by the identification unit 232 with the weight of the contents estimated by the estimation unit 233 and stores it in the memory unit 22 as linked information 221. Note that the linked cargo information is not limited to the weight of the contents. The linked cargo information may include the weight of the cargo L, including the weight of the outer packaging. Alternatively, the linked cargo information may include the total weight of the pallet P, including the weight of the pallet P. This eliminates the need for workers to manually record the weight of the cargo L (contents) for each pallet P on paper.

[0073] [Example of detecting the status of the tip of fork 3] Figure 6 shows an example of detecting the condition of the tip of the fork 3 according to the first embodiment. Figure 6 shows a schematic cross-sectional view of the pallet P and the fork 3 inserted into the fork insertion hole 7 of the pallet P, viewed from the side (positive Z-axis direction).

[0074] As shown in Figure 6, when the fork 3 is inserted into the fork insertion hole 7 of the pallet P, the control device 10 detects that the tip of the fork 3 has been inserted into the fork insertion hole 7 based on the sensing results from the situation detection sensor 5.

[0075] In the example shown in Figure 6, the situation detection sensor 5 detects the conditions below the fork 3. For example, suppose the situation detection sensor 5 is a Lidar and radar device, and detects information about targets around the fork 3.

[0076] In this case, when the fork 3 is inserted into the fork insertion hole 7 of the pallet P, for example, the sensing result of the situation detection sensor 5 changes from the road surface R to the pallet P. When the situation detection sensor 5 detects the pallet P, the detection unit 131 of the control device 10 determines that the tip of the fork 3 has been inserted into the fork insertion hole 7.

[0077] Alternatively, if the situation detection sensor 5 is a camera, the detection unit 131 of the control unit 13 determines that the tip of the fork 3 has been inserted into the fork insertion hole 7 if the area of ​​the palette P included in the captured image (hereinafter also referred to as the palette area) exceeds the insertion threshold.

[0078] The detection unit 131 identifies the palette region included in the captured image based on, for example, the color of the palette P. The detection unit 131 determines, for example, that the tip of the fork 3 has been inserted into the fork insertion hole 7 if the proportion of the palette region in the captured image exceeds an insertion threshold.

[0079] In this case, the detection unit 131 may be configured to detect the edges of the pallet area. For example, the detection unit 131 may determine whether the fork 3 was inserted horizontally to the longitudinal direction of the fork insertion hole 7 of the pallet P, depending on the inclination of the edge.

[0080] If the fork 3 is not inserted horizontally to the longitudinal direction of the fork insertion hole 7, the motion control unit 132 controls the forklift 1 so that the fork 3 is inserted horizontally to the longitudinal direction of the fork insertion hole 7. This allows the forklift 1 to lift the pallet P more safely.

[0081] Having detected that the tip of the fork 3 has been inserted into the fork insertion hole 7, the detection unit 131 then determines whether or not the tip is protruding from the fork insertion hole 7.

[0082] Figure 7 shows another example of detecting the status of the tip of the fork 3 according to the first embodiment. Figure 7 shows a schematic cross-sectional view of the pallet P and the fork 3 inserted into the fork insertion hole 7 of the pallet P, viewed from the side (positive Z-axis direction).

[0083] As shown in Figure 7, when the fork 3 exits the fork insertion hole 7 of the pallet P, the control device 10 detects that the tip of the fork 3 has exited the fork insertion hole 7 based on the sensing results from the situation detection sensor 5.

[0084] For example, suppose the situation detection sensor 5 is a Lidar and radar device, and detects information about a target below the fork 3. In this case, when the fork 3 exits the fork insertion hole 7 of the pallet P, for example, the sensing result of the situation detection sensor 5 changes from the pallet P to the road surface R. When the situation detection sensor 5 detects the road surface R, the detection unit 131 determines that the tip of the fork 3 has exited the fork insertion hole 7.

[0085] Alternatively, if the situation detection sensor 5 is a camera, the detection unit 131 determines that the tip of the fork 3 has emerged from the fork insertion hole 7 when the area of ​​the palette P included in the captured image (hereinafter also referred to as the palette area) falls below the protrusion threshold.

[0086] The detection unit 131 identifies the palette region included in the captured image based on, for example, the color of the palette P. The detection unit 131 determines, for example, that the tip of the fork 3 has emerged from the fork insertion hole 7 if the proportion of the palette region in the captured image falls below a protrusion threshold.

[0087] In this case, the detection unit 131 may be configured to detect the edges of the pallet area. For example, the detection unit 131 may determine whether the fork 3 was inserted horizontally to the longitudinal direction of the fork insertion hole 7 of the pallet P, depending on the inclination of the edge.

[0088] If the fork 3 is not inserted horizontally to the longitudinal direction of the fork insertion hole 7, the motion control unit 132 controls the forklift 1 so that the fork 3 is inserted horizontally to the longitudinal direction of the fork insertion hole 7. This allows the forklift 1 to lift the pallet P more safely.

[0089] Here, for forklift 1 to safely transport the load L, it is important to lift the pallet P more stably. Forklift 1 can lift the pallet P even if the tips of the forks 3 do not extend through the fork insertion holes 7 of the pallet P. However, if the tips of the forks 3 extend through the fork insertion holes 7 of the pallet P, forklift 1 can lift the pallet P more safely than if they do not. This is because when the tips of the forks 3 extend through the fork insertion holes 7 of the pallet P, the contact area between the forks 3 and the pallet P is larger, allowing the forks 3 to support the pallet P more stably. Therefore, by lifting the pallet P with the tips of the forks 3 extending through the fork insertion holes 7 of the pallet P, forklift 1 can transport the load L more safely.

[0090] The determination made by the detection unit 131 is not limited to the examples described above. For example, the detection unit 131 may determine whether the tip of the fork 3 is inserted into the fork insertion hole 7 or whether the tip of the fork 3 is protruding from the fork insertion hole 7 based on the difference in brightness around the tip of the fork 3.

[0091] The detection unit 131 determines, for example, that the tip of the fork 3 has been inserted into the fork insertion hole 7 if the captured image is dark, or more specifically, if the average brightness value of the captured image is less than the brightness threshold.

[0092] The detection unit 131 determines, for example, that the tip of the fork 3 is protruding from the fork insertion hole 7 if the captured image is bright, or more specifically, if the average brightness value of the captured image is equal to or greater than the brightness threshold.

[0093] In this case, the detection unit 131 determines whether or not the area around the tip of the fork 3 is bright using the image captured by the camera. However, the method by which the detection unit 131 determines the brightness is not limited to this. For example, if the situation detection sensor 5 is a brightness sensor, the detection unit 131 determines whether or not the area around the tip of the fork 3 is bright according to the brightness detected by the brightness sensor.

[0094] The detection unit 131 determines, for example, that the tip of the fork 3 has been inserted into the fork insertion hole 7 if the area around the tip of the fork 3 is dark, or more specifically, if the detection result (luminance value) of the luminance sensor is below a threshold.

[0095] The detection unit 131 determines, for example, that the tip of the fork 3 is protruding from the fork insertion hole 7 if the area around the tip of the fork 3 is bright, or more specifically, if the detection result (brightness value) of the brightness sensor is above a threshold.

[0096] [Example of processing by control device 10] Figure 8 is a flowchart showing an example of the procedure for processing performed by the control device 10 according to the first embodiment.

[0097] The control unit 13 of the control device 10 detects the pallet P using the situation detection sensor 5 (step S101). Subsequently, the control unit 13 controls the vehicle body 2 to move it to the vicinity of the pallet P (step S102).

[0098] Next, the control unit 13 detects the position of the fork insertion hole 7 of the pallet P (step S103) and controls the lifting unit 4 to move the fork 3 to the height of the fork insertion hole 7 (step S104).

[0099] The control unit 13 moves the vehicle body 2 to insert the forks 3 into the pallet P (step S105). The control unit 13 determines whether the tip of the forks 3 has come out of the pallet P (step S106).

[0100] If the tip of the fork 3 is not protruding from the pallet P (step S106; No), the control unit 13 returns to step S105 and inserts the fork 3 into the pallet P. On the other hand, if the tip of the fork 3 is protruding from the pallet P (step S106; Yes), the lifting unit 4 is controlled to raise the fork 3 and lift the pallet P (step S107).

[0101] The control unit 13 controls the vehicle body 2 with the pallet P lifted up and moves it to the target position (step S108). At the target position, the control unit 13 controls the lifting unit 4 to lower the fork 3 and place the pallet P on it (step S109), and the process ends.

[0102] [Example of processing by weight detection device 20] Figure 9 is a flowchart showing an example of the procedure performed by the weight detection device 20 according to the first embodiment.

[0103] The control unit 23 of the weight detection device 20 detects the appearance information of the load L placed on the pallet P (step S201).

[0104] Next, the control unit 23 detects the load applied to the fork 3 from the load sensor 6 while the pallet P is lifted by the fork 3 (step S202).

[0105] The control unit 23 identifies the outer packaging of the load L based on the visual information (step S203) and estimates the weight of the outer packaging (step S204).

[0106] The control unit 23 estimates the weight of the contents based on the load on the fork 3 and the weight of the outer packaging (step S205). The control unit 23 identifies the contents information related to the load L based on the external appearance information (step S206).

[0107] The control unit 23 stores the linked information 221, which combines the identified cargo information and the estimated weight of the contents, in the storage unit 22 (step S207), and terminates the process.

[0108] <Second Embodiment> In the first embodiment described above, the situation detection sensor 5 was assumed to detect conditions downward (negative Y-axis direction). However, the situation detection sensor 5 may be configured to detect conditions in the surrounding area other than downward. For example, in the second embodiment, a window portion 8 is formed at the tip of the fork 3. This allows the situation detection sensor 5 to detect conditions in the surrounding area other than downward.

[0109] In the following description, the same reference numerals are used for parts that are the same as or equivalent to those in the first embodiment, and descriptions of parts that are the same as or equivalent to those in the first embodiment may be omitted.

[0110] Figure 10 is a schematic side view of the forklift 1 according to the second embodiment. Figure 11 is a diagram showing an example of the configuration of the window section 8 according to the first embodiment. Figure 11 shows a cross-section taken along line III-III in Figure 10. Also, Figure 10 shows a view of the fork 3 from diagonally below, from the tip side to the base side.

[0111] As shown in Figure 10, a window portion 8 is formed at the tip of the fork 3. The window portion 8 is formed as an opening at the tip of the fork 3 so as to communicate with the inside of the recess 3a. The window portion 8 is formed above and to the side of the situation detection sensor 5 located inside the recess 3a. In this embodiment, the window portion 8 is formed above the situation detection sensor 5 and to the left and right (positive and negative Z-axis) sides.

[0112] With this configuration, the situation detection sensor 5 can detect the conditions above and to the side of the fork 3 through the window portion 8 formed at the tip of the fork 3. This allows the control device 10 to more accurately grasp the conditions at the tip of the fork 3. Furthermore, the ability to detect the conditions above and to the side of the fork 3 enables accurate insertion of the fork 3 into the fork insertion hole 7 of the pallet P. In addition, if the window portion 8 is formed on the side of the situation detection sensor 5, the width of the fork 3 can be easily adjusted.

[0113] Furthermore, by enabling detection of the fork 3's status from either above or to the side, the control device 10 can determine whether the tip of the fork 3 has been inserted into the fork insertion hole 7, depending on whether it has detected the pallet P from either above or to the side. Similarly, the control device 10 can determine whether the tip of the fork 3 has exited the fork insertion hole 7.

[0114] Here, various shapes of pallets P may be used to transport the load L. For example, the bottom of the fork insertion hole 7 of the pallet P may be missing, or part of the bottom may be missing. When such a pallet P is used, the control device 10 may not be able to determine from the condition of the underside of the forks 3 whether the tip of the fork 3 has been inserted into the fork insertion hole 7 or has come out of the fork insertion hole 7 (condition of the tip of the fork 3).

[0115] Therefore, in this embodiment, by forming a window portion 8 at the tip of the fork 3, the control device 10 is enabled to detect the condition of at least one of the above and side of the fork 3. This allows the control device 10 to determine the condition of the tip of the fork 3 with greater accuracy.

[0116] Furthermore, the window portion 8 is not limited to being formed above and on the left and right sides of the situation detection sensor 5. For example, it may be formed only above the situation detection sensor 5, or only on the outer (or inner) side of the left or right side of the situation detection sensor 5.

[0117] Furthermore, the window portion 8 may be formed as a rectangular hole, or as a circular or elliptical hole.

[0118] Furthermore, the window portion 8 is covered by a glass member 8a. The glass member 8a is, for example, a transparent tempered glass member. When the situation detection sensor 5 is a camera, the glass member 8a is preferably colorless and transparent. However, when the situation detection sensor 5 is a Lidar or radar device, the glass member 8a does not necessarily have to be transparent.

[0119] The glass member 8a is provided to correspond to the shape of the opening (internal) of the window portion 8. In other words, the glass member 8a is provided to fill the window portion 8. For this reason, the glass member 8a is substantially flush with the outer circumferential surface of the fork 3.

[0120] With this configuration, for example, even when the fork 3 is operated, damage to the situation detection sensor 5 due to external forces such as the fork 3 contacting the pallet P can be suppressed, and dust and other debris entering through the window 8 can be suppressed from accumulating on the situation detection sensor 5. This increases the durability of the situation detection sensor 5.

[0121] Furthermore, by making the glass component 8a a component made of tempered glass, appropriate strength is ensured for the glass component 8a.

[0122] Furthermore, the glass member 8a may be formed, for example, inside the window portion 8, and thinner than the thickness of the window portion 8. Alternatively, the glass member 8a may be thinner than the thickness of the window portion 8 and provided on the outermost part of the window portion 8 so as to be substantially flush with the outer peripheral surface of the fork 3. In this case, in the case of the window portion 81 above the situation detection sensor 5, the glass member 8a will be substantially flush with the top surface of the fork 3, and in the case of the window portions 82 and 83 on the left and right sides of the situation detection sensor 5, the glass member 8a will be substantially flush with the left and right sides of the fork 3, respectively.

[0123] Furthermore, the window section 8 and glass member 8a are provided on each of the left and right forks 3L and 3R, respectively, when the forks 3 are composed of, for example, a pair of left and right forks.

[0124] Furthermore, the window portion 8 may be covered with a covering member. For example, the window portion 8 may be covered with a mesh member having a mesh structure. The mesh member may be made of metal or a hard material (for example, a hard synthetic resin). If the mesh member is made of a hard material, engineering plastics or the like may be used as the mesh member.

[0125] The mesh member is provided, for example, to correspond to the opening shape of the window portion 8. The mesh member is substantially flush with the outer circumferential surface of the fork 3.

[0126] In this configuration, a glass member 8a is provided as a member to cover the window portion 8, but the member to cover the window portion 8 is not limited to this. The member to cover the window portion 8 may be, for example, a member made of acrylic resin (acrylic member).

[0127] Furthermore, while it is desirable for the acrylic component to be transparent when the situation detection sensor 5 is a camera, it is not necessarily required to be transparent when the situation detection sensor 5 is a Lidar or radar device.

[0128] Furthermore, if the situation detection sensor 5 is a Lidar or radar device, a material such as a cloth material that transmits light or radio waves (cloth material) may be used to cover the window portion 8. In this case, the cloth material is, for example, a reinforced cloth with a resin coating. Therefore, the cloth material has appropriate strength.

[0129] Furthermore, a louver-shaped member (louver member) consisting of multiple plates arranged parallel to each other at predetermined intervals may be used as a component to cover the window portion 8. Since gaps are formed in the louver member, even if the situation detection sensor 5 is a camera, it is possible to detect the situation above and to the side of the fork 3 through the gaps.

[0130] Furthermore, if a louver member is used, and the configuration allows for the opening and closing of the window section 8 by the louver member, it is possible to control the louver member so that, for example, the window section 8 is opened when the fork 3 is inserted into the fork insertion hole 7 of the pallet P, and closed in other cases.

[0131] <Example Hardware Configuration> Figure 12 is a schematic diagram showing an example of the hardware configuration of a computer 1200 that functions as a control device 10 and / or a weight detection device 20. A program installed on the computer 1200 can cause the computer 1200 to function as one or more "parts" of the apparatus according to this embodiment, or to cause the computer 1200 to execute operations associated with the apparatus according to this embodiment or such one or more "parts", and / or to cause the computer 1200 to execute a process or a stage of such process according to this embodiment. Such a program may be executed by the CPU 1212 to cause the computer 1200 to execute specific operations associated with some or all of the blocks in the flowcharts and block diagrams described herein.

[0132] The computer 1200 according to this embodiment includes a CPU 1212, RAM 1214, and a graphics controller 1216, which are interconnected by a host controller 1210. The computer 1200 also includes input / output units such as a communication interface 1222, a storage device 1224, a DVD drive, and an IC card drive, which are connected to the host controller 1210 via an input / output controller 1220. The DVD drive may be a DVD-ROM drive and a DVD-RAM drive, etc. The storage device 1224 may be a hard disk drive and a solid-state drive, etc. The computer 1200 also includes input / output units such as a ROM 1230 and a keyboard, which are connected to the input / output controller 1220 via an input / output chip 1240.

[0133] The CPU 1212 operates according to the programs stored in the ROM 1230 and RAM 1214, thereby controlling each unit. The graphics controller 1216 acquires the image data generated by the CPU 1212 and stores it in the frame buffer provided in RAM 1214 or within itself, so that the image data is displayed on the display device 1218.

[0134] The communication interface 1222 communicates with other electronic devices via a network. The storage device 1224 stores programs and data used by the CPU 1212 in the computer 1200. The DVD drive reads programs or data from a DVD-ROM or the like and provides them to the storage device 1224. The IC card drive reads programs and data from an IC card and / or writes programs and data to an IC card.

[0135] The ROM 1230 stores boot programs and / or hardware-dependent programs of the computer 1200, which are executed by the computer 1200 upon activation. The input / output chip 1240 may also connect various input / output units to the input / output controller 1220 via USB ports, parallel ports, serial ports, keyboard ports, mouse ports, etc.

[0136] The program is provided on a computer-readable storage medium such as a DVD-ROM or IC card. The program is read from the computer-readable storage medium and installed on a storage device 1224, RAM 1214, or ROM 1230, which are examples of computer-readable storage media, and executed by the CPU 1212. The information processing described within these programs is read by the computer 1200, resulting in coordination between the program and the various types of hardware resources described above. The apparatus or method may be configured to realize the operation or processing of information in accordance with the use of the computer 1200.

[0137] For example, when communication is performed between a computer 1200 and an external device, the CPU 1212 may execute a communication program loaded into RAM 1214 and, based on the processing described in the communication program, instruct the communication interface 1222 to perform communication processing. Under the control of the CPU 1212, the communication interface 1222 reads transmission data stored in a transmission buffer area provided in a recording medium such as RAM 1214, storage device 1224, DVD-ROM, or IC card, transmits the read transmission data to the network, or writes received data received from the network to a reception buffer area provided on the recording medium.

[0138] Furthermore, the CPU 1212 may read all or necessary parts of a file or database stored on an external recording medium such as the storage device 1224, a DVD drive (DVD-ROM), or an IC card into the RAM 1214, and perform various types of processing on the data in the RAM 1214. The CPU 1212 may then write the processed data back to the external recording medium.

[0139] Various types of information, such as various types of programs, data, tables, and databases, may be stored on the recording medium and subjected to information processing. The CPU 1212 may perform various types of processing on the data read from RAM 1214, including various types of operations, information processing, conditional judgments, conditional branching, unconditional branching, information retrieval / replacement, etc., as described throughout this disclosure and specified by the program instruction sequence, and write the results back to RAM 1214. The CPU 1212 may also retrieve information in files, databases, etc., within the recording medium. For example, if multiple entries are stored in the recording medium, each having an attribute value of a first attribute associated with an attribute value of a second attribute, the CPU 1212 may search among the multiple entries for an entry that matches the specified condition for the attribute value of the first attribute, read the attribute value of the second attribute stored in that entry, and thereby obtain the attribute value of the second attribute associated with the first attribute that satisfies the predetermined condition.

[0140] The program or software module described above may be stored on or near the computer 1200 in a computer-readable storage medium. Alternatively, a recording medium such as a hard disk or RAM provided within a server system connected to a dedicated communication network or the Internet can be used as a computer-readable storage medium, thereby providing the program to the computer 1200 via the network.

[0141] In this embodiment, blocks in the flowchart and block diagram may represent a stage in a process in which an operation is performed or a "part" of a device that has the role of performing an operation. A particular stage and "part" may be implemented by a dedicated circuit, a programmable circuit supplied with computer-readable instructions stored on a computer-readable storage medium, and / or a processor supplied with computer-readable instructions stored on a computer-readable storage medium. The dedicated circuit may include digital and / or analog hardware circuits, and may include integrated circuits (ICs) and / or discrete circuits. The programmable circuit may include reconfigurable hardware circuits, such as field-programmable gate arrays (FPGAs) and programmable logic arrays (PLAs), which include logical AND, logical OR, exclusive OR, negated AND, negated OR, and other logical operations, flip-flops, registers, and memory elements.

[0142] A computer-readable storage medium may include any tangible device capable of storing instructions to be executed by a suitable device, and as a result, a computer-readable storage medium having instructions stored therein will comprise a product that includes instructions that can be executed to create means for performing operations specified in a flowchart or block diagram. Examples of computer-readable storage media may include electronic storage media, magnetic storage media, optical storage media, electromagnetic storage media, semiconductor storage media, etc. More specific examples of computer-readable storage media may include floppy disks, diskettes, hard disks, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), electrically erasable programmable read-only memory (EEPROM), static random access memory (SRAM), compact disk read-only memory (CD-ROM), digital multipurpose disc (DVD), Blu-ray® disc, memory stick, integrated circuit card, etc.

[0143] Computer-readable instructions may include assembler instructions, instruction set architecture (ISA) instructions, machine instructions, machine-dependent instructions, microcode, firmware instructions, state setting data, or source code or object code written in any combination of one or more programming languages, including object-oriented programming languages ​​such as Smalltalk®, Java®, C++, and traditional procedural programming languages ​​such as the C programming language or similar languages.

[0144] Computer-readable instructions may be provided to a general-purpose computer, a special-purpose computer, or a programmable circuit, either locally or via a wide area network (WAN) such as a local area network (LAN) or the internet, so that the computer-readable instructions may be executed by the processor or programmable circuit of a general-purpose computer, a special-purpose computer, or other programmable data processing device, in order to generate means for performing operations specified in a flowchart or block diagram. Examples of processors include computer processors, processing units, microprocessors, digital signal processors, controllers, microcontrollers, and the like.

[0145] Although the present invention has been described above using embodiments, the technical scope of the present invention is not limited to the scope described in the above embodiments. It will be apparent to those skilled in the art that various modifications or improvements can be made to the above embodiments. It will be clear from the claims that such modified or improved forms may also be included in the technical scope of the present invention.

[0146] It should be noted that the execution order of operations, procedures, steps, and stages in the devices, systems, programs, and methods shown in the claims, specifications, and drawings is not explicitly stated as "before," "prior to," etc., and that these can be implemented in any order unless the output of a previous process is used in a later process. Even if the operation flow in the claims, specifications, and drawings is described using phrases such as "first," "next," etc. for convenience, it does not mean that it is essential to perform the operations in that order. [Explanation of Symbols]

[0147] 1 Forklift 2. Running vehicle 3 forks 3a Recess 4. Lifting section 5. Situation detection sensor 6. Load Sensor 7 Fork insertion holes 8 Window section 10 Control device 11,21 Communications Department 12,22 Storage section 13,23 Control Unit 20 Weight detection device 131,231 Detection unit 132 Operation Control Unit 221 Linked Information 232 Specific part 233 Estimation Department 234 Memory Processing Unit L Load P Palette

Claims

1. The vehicle body and A fork provided in front of the vehicle body, with a recess formed at its tip, where the part facing the road surface on which the vehicle body travels is recessed; A sensor housed in the recess for detecting the condition of the road surface, A determination unit that determines whether or not the tip of the fork is protruding from the fork insertion hole provided in the pallet, based on the sensing results of the aforementioned sensor, A forklift equipped with [specific features / equipment].

2. The sensor has a camera that captures the surrounding conditions of the tip and outputs an image. The forklift according to claim 1, wherein the determination unit determines that the tip is protruding from the fork insertion hole if the ratio of the pallet area included in the image to the image is less than or equal to a protrusion threshold.

3. The forklift according to claim 2, wherein the determination unit determines that the tip is protruding from the fork insertion hole if, after the tip is inserted into the fork insertion hole, the ratio of the pallet area to the image becomes less than or equal to the protrusion threshold.

4. The determination unit determines whether or not the tip of the fork has been inserted into the fork insertion hole, as described in claim 1.

5. The sensor has a camera that captures the surrounding conditions of the tip and outputs an image. The forklift according to claim 4, wherein the determination unit determines that the tip is inserted into the fork insertion hole if the proportion of the image to the pallet area included in the image is equal to or greater than an insertion threshold.

6. The sensor has a camera that captures the surrounding conditions of the tip and outputs an image, The determination unit detects the edges of the pallet area included in the image and determines whether the fork was inserted horizontally with respect to the longitudinal direction of the fork insertion hole according to the inclination of the edge, as described in claim 1.

Images