Loading control device

Abstract

Provided is a loading control device capable of shortening the travel distance of a forklift when a pallet is loaded on a platform by the forklift. A loading control device (1) is provided with: a tray presence / absence determination unit (32) that determines whether or not there is an existing tray (15A) that has been placed on a platform (18); a laser sensor (22) and a tray position detection unit (36) that detect the position of the existing tray when it is determined that the existing tray is present on the platform; a loading position calculation unit (37) that calculates a next loading position (P) of a loading target tray (15B) that is subsequently loaded on the platform on the basis of the position of the existing tray (15A); and a loading control unit (38) that controls the forklift (2) so that the tray (15B) to be loaded is loaded to the next loading position (P), and the loading position calculation unit (37) calculates, as the next loading position (P), a position adjacent to the existing tray (15A) in the left-right direction on the platform (18).

Description

Technical Field

[0001] The present invention relates to a loading control device. Background Art

[0002] As an existing loading control device, for example, as described in Patent Document 1, the following technology is known: the position of an object is detected by an external sensor such as a laser sensor, points representing a cargo bed are extracted based on a set of points representing the position of the object, i.e., point group data, to determine the loading position for loading the goods on the cargo bed.

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application Publication No. 2023-30983 Summary of the invention

[0006] Problem that the invention aims to solve

[0007] However, when loading a pallet onto a cargo bed of a truck or the like by a forklift, the forklift detects the cargo bed while traveling along the edge of the cargo bed to calculate the loading position. In order to detect the cargo bed in this way, the forklift needs to travel around the cargo bed to a certain extent.

[0008] An object of the present invention is to provide a loading control device capable of shortening the travel distance of a forklift when loading a pallet onto a cargo platform using a forklift.

[0009] Solutions for solving problems

[0010] (1) One embodiment of the present invention is a loading control device for loading a pallet onto a cargo platform using a forklift having multiple forks for holding a pallet, the device comprising: a pallet presence determination unit for determining whether there is an existing pallet already placed on the cargo platform; a pallet detection unit for detecting the position of the existing pallet when the pallet presence determination unit determines that there is an existing pallet on the cargo platform; a loading position calculation unit for calculating the loading position of a loading object pallet to be loaded onto the cargo platform next based on the position of the existing pallet detected by the pallet detection unit; and a loading control unit for controlling the forklift so that the loading object pallet is loaded onto the loading position calculated by the loading position calculation unit, the loading position calculation unit calculating a position on the cargo platform adjacent to the existing pallet in the left-right direction.

[0011] In such a loading control device, when it is determined that there is an existing pallet already placed on the cargo platform, the position of the existing pallet is detected. And based on the position of the existing pallet, the loading position of the next loading pallet to be loaded on the cargo platform is calculated. At this time, the position adjacent to the existing pallet in the left-right direction on the cargo platform is calculated as the loading position. And the forklift is controlled in such a manner that the loading pallet is loaded to the loading position. In this way, when there is an existing pallet already placed on the cargo platform, the loading position of the loading pallet is calculated based on the position of the existing pallet. Therefore, it is not necessary to drive the forklift around the cargo platform to detect the cargo platform in order to calculate the loading position of the loading pallet. As a result, when the forklift loads the pallet on the cargo platform, the travel distance of the forklift is shortened.

[0012] (2) Alternatively, in the above-mentioned (1), the pallet detection unit may include a laser sensor mounted on the side of the forklift and configured to detect the distance to the existing pallet by irradiating a laser toward the existing pallet and receiving reflected light of the laser, and the position of the existing pallet may be detected based on point group data of the laser sensor.

[0013] In such a configuration, the laser sensor is mounted on the side of the forklift, so when the forklift is in a horizontal position relative to the cargo platform, the laser can be irradiated toward the existing pallet placed on the cargo platform to detect the position of the existing pallet. In this case, when the forklift approaches the cargo platform, the entire front surface of the existing pallet is easily within the irradiation range of the laser sensor. Therefore, the position of the existing pallet can be detected even in a narrow passage or a narrow factory.

[0014] (3) In the above (1) or (2), the pallet detection unit may detect the position coordinates and the tilt angle of the existing pallet as the position of the existing pallet.

[0015] In such a configuration, even if an existing pallet is placed on the cargo bed in an inclined state due to the weight of the cargo placed on the existing pallet, the loading position of the loading target pallet can be appropriately calculated based on the position coordinates and the tilt angle of the existing pallet.

[0016] (4) Alternatively, in any one of the above (1) to (3), the width of the pallet to be loaded is equal to the width of the existing pallet, and the loading position calculation unit calculates a position that is offset in the left-right direction relative to the existing pallet by the width of the existing pallet as the loading position.

[0017] In such a configuration, pallets adjacent to each other in the left-right direction are loaded onto the cargo platform without any gap therebetween, so that a large number of pallets can be loaded onto the cargo platform.

[0018] (5) Alternatively, in any one of the above (1) to (4), the loading control device further comprises: a cargo bed detection unit, which detects the position of an edge of the loading side of the cargo bed when the pallet presence determination unit determines that there is no existing pallet on the cargo bed; and an initial loading position calculation unit, which calculates the loading position of the loading object pallet that is first loaded onto the cargo bed based on the position of the edge of the loading side of the cargo bed detected by the cargo bed detection unit, and the loading control unit controls the forklift in such a manner that the loading object pallet is loaded to the loading position calculated by the initial loading position calculation unit and the loading position calculation unit.

[0019] In such a configuration, when it is determined that there is no existing pallet on the cargo platform, the position of the edge of the cargo platform on the loading side is detected. And based on the position of the edge of the cargo platform on the loading side, the loading position of the first loading target pallet is calculated. Therefore, even in a state where there is no existing pallet on the cargo platform, the first loading target pallet is loaded at an appropriate position on the cargo platform.

[0020] (6) Alternatively, in the above (5), the cargo bed detection unit includes a first laser sensor mounted on the upper portion of the forklift and detecting the distance to the cargo bed by irradiating a laser toward the cargo bed and receiving reflected light of the laser, and the position of the edge of the loading side of the cargo bed is detected based on point group data of the first laser sensor.

[0021] In such a configuration, the first laser sensor is mounted on the upper portion of the forklift, and thus the first laser sensor acquires point group data of a wide range around the forklift, thereby being able to accurately detect the position of the edge of the loading side of the cargo bed.

[0022] (7) Alternatively, in the above (6), the pallet detection unit may include a second laser sensor mounted on the side of the forklift and detecting the distance of the existing pallet by irradiating a laser toward the existing pallet and receiving reflected light of the laser, and the position of the existing pallet is detected based on point group data of the second laser sensor.

[0023] In such a configuration, the second laser sensor is mounted on the side of the forklift, so when the forklift is in a horizontal position relative to the cargo platform, it can irradiate the laser toward the existing pallet placed on the cargo platform to detect the position of the existing pallet. In this case, when the forklift approaches the cargo platform, the entire front surface of the existing pallet is easily included in the irradiation range of the laser of the second laser sensor. Therefore, the position of the existing pallet can be detected even in a narrow passage or a narrow factory.

[0024] (8) In the above (7), the irradiation range of the laser light of the second laser sensor in the horizontal direction may be narrower than the irradiation range of the laser light of the first laser sensor in the horizontal direction.

[0025] In such a configuration, a second laser sensor which is cheaper than the first laser sensor can be used. In addition, the second laser sensor acquires point group data with a higher density than the first laser sensor, so the position of an existing pallet placed on the cargo platform can be detected with high accuracy.

[0026] (9) Alternatively, in any one of the above (1) to (8), the forklift has four forks in a manner capable of simultaneously holding two pallets, the pallet presence determination unit determines whether there are two existing pallets that are arranged side by side on the cargo platform, the pallet detection unit detects the position of either of the two existing pallets when the pallet presence determination unit determines that there are two existing pallets, the loading position calculation unit calculates the loading positions of two loading object pallets to be loaded onto the cargo platform next based on the position of either of the two existing pallets detected by the pallet detection unit, and the loading control unit controls the forklift in a manner such that the two loading object pallets are simultaneously loaded into the loading positions calculated by the loading position calculation unit.

[0027] In such a configuration, two loading target pallets can be loaded simultaneously by a forklift having four forks so as to be adjacent to two existing pallets that are already arranged side by side on the cargo platform in the left-right direction. Therefore, a plurality of pallets can be loaded efficiently on the cargo platform.

[0028] (10) It may also be that in the above (9), the width of the loading target pallet is equal to the width of the existing pallet, and when the position of the existing pallet on one of the two existing pallets is detected, the loading position calculation unit calculates a position that is offset to the other left or right side by 2.5 times the width of the existing pallet relative to the existing pallet on one of the two existing pallets as the loading position, and when the position of the existing pallet on the other left or right side of the two existing pallets is detected, the loading position calculation unit calculates a position that is offset to the other left or right side by 1.5 times the width of the existing pallet relative to the existing pallet on the other left or right side as the loading position.

[0029] In such a configuration, when the position of an existing pallet on either the left or right side is detected, pallets adjacent to each other in the left and right directions are loaded onto the cargo platform without any gaps therebetween. Therefore, a large number of pallets can be loaded onto the cargo platform.

[0030] Effects of the Invention

[0031] According to the present invention, when a pallet is loaded onto a cargo bed by a forklift, the travel distance of the forklift can be shortened. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 This is a block diagram showing the configuration of a loading control device according to one embodiment of the present invention.

[0033] Figure 2 It is equipped with Figure 1 A side view of a forklift shown with a load control device.

[0034] Figure 3 It is shown by Figure 1 Flowchart of the steps of the cargo bed edge position detection process executed by the cargo bed edge position detection unit shown.

[0035] Figure 4 It is shown by Figure 1 Flowchart of the steps of the pallet position detection process performed by the pallet position detection unit shown.

[0036] Figure 5 This is a plan view showing a state in which the first loading target pallet is loaded onto the cargo bed of a truck by a forklift.

[0037] Figure 6 The diagram is a top view and a schematic front view showing a state in which the position of an existing pallet placed on a cargo bed of a truck is detected using a laser sensor mounted on the side of a forklift.

[0038] Figure 7 It is shown by Figure 1 A side view of the next loading position of the loading target pallet calculated by the loading position calculation unit shown.

[0039] Figure 8 This is a plan view showing a state in which a forklift holding a pallet to be loaded is moved toward a next loading position.

[0040] Fig. 9 The loading object tray is loaded on Figure 7 A side view of the state of the next loading position is shown.

[0041] Fig.10 This is a schematic front view showing a state in which the position of the side end of the cargo bed of a truck is detected using a laser sensor mounted on the upper portion of a forklift.

[0042] Fig.11 It is a block diagram showing the structure of a loading control device according to another embodiment of the present invention.

[0043] Fig.12 This is a plan view showing a state in which the positions of two left and right existing pallets placed on a cargo bed of a truck are detected using a laser sensor mounted on the side of a forklift having four forks.

[0044] Fig.13 This is a conceptual diagram showing the next loading position calculated when the positions of two existing left and right pallets placed on the cargo bed of a truck are detected.

[0045] Fig.14This is a conceptual diagram showing the offset amount when picking up two left and right loading target pallets placed in the pallet placement area.

[0046] Description of Reference Numerals

[0047] 1, 1A…loading control device; 2, 2A…forklift; 12…fork; 15…pallet; 15a…front surface; 15A…existing pallet; 15B…pallet to be loaded; 18…cargo platform; 18b…side edge (edge); 20…laser sensor (first laser sensor, cargo platform detection unit); 22…laser sensor (second laser sensor, pallet detection unit); 32, 32A…pallet presence determination unit; 33…cargo platform edge position detection unit (cargo platform detection unit); 34, 34A…initial loading position calculation unit; 36, 36A…pallet position detection unit (pallet detection unit); 37, 37A…loading position calculation unit; 38, 38A…loading control unit; P0…initial loading position (loading position); P…next loading position (loading position); W…width. DETAILED DESCRIPTION

[0048] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. In addition, in the drawings, the same or equivalent elements are denoted by the same reference numerals, and repeated descriptions are omitted.

[0049] Figure 1 FIG. 1 is a block diagram showing the structure of a loading control device according to an embodiment of the present invention. Figure 1 In this embodiment, the loading control device 1 is mounted on Figure 2 Such a forklift 2 is shown. The forklift 2 is a reach type forklift. The forklift 2 includes a travel device 3 and a cargo handling device 4 which is arranged in front of the travel device 3 and performs cargo handling.

[0050] The travel device 3 includes a vehicle body 5, a pair of left and right front legs 6 extending from the lower portion of the vehicle body 5 to the front of the vehicle body 5, a front wheel 7 which is a steering wheel provided at the top end (front end) of each front leg 6, and a rear wheel 8 which is a driving wheel provided at the left rear portion of the vehicle body 5. A caster (not shown) is provided at the right rear portion of the vehicle body 5.

[0051] The cargo handling device 4 includes a mast 10 disposed between the front legs 6 and movable along the front legs 6 in the front-rear direction of the vehicle body 5; a pair (two) of left and right forks 12 mounted to the mast 10 via a lifting bracket 11 so as to be able to be raised and lowered, and holding a pallet 15 (see Figures 5 to 9 ); a lifting cylinder 13, which lifts the fork 12 via the lifting bracket 11; and a forward extension cylinder 14 (reference Figure 1), which moves the fork 12 in the front-rear direction of the vehicle body 5 (advance and retreat) by moving the mast 10 in the front-rear direction of the vehicle body 5. In addition, the cargo handling device 4 may also have a side shift cylinder that moves the fork 12 in the left-right direction (lateral direction).

[0052] The pallet 15 is a cargo loading and unloading platform for loading cargo (not shown). The pallet 15 is, for example, a flat pallet. The pallet 15 is substantially quadrilateral in plan view. Two fork holes 16 (see FIG. 1 ) are provided on the pallet 15 for inserting the forks 12. Figure 7 and Fig. 9 The fork hole 16 extends from the front surface 15a of the tray 15 toward the rear side.

[0053] The loading control device 1 is used to load a pallet 15 onto a cargo platform 18 of a truck 17 (see Figures 5 to 9 ). The loading control device 1 loads the pallets 15 onto the cargo platform 18 in sequence from the front side to the rear side of the truck 17 without any gaps. That is, the loading control device 1 loads the pallets 15 adjacent to each other in the left-right direction on the cargo platform 18. The widths W of the pallets 15 loaded onto the cargo platform 18 are all equal.

[0054] The loading control device 1 includes a laser sensor 20 , a map storage unit 21 , a laser sensor 22 , a travel drive unit 23 , a cargo loading and unloading drive unit 24 , and a controller 25 .

[0055] like Figure 2 As shown, the laser sensor 20 is mounted on the upper part of the forklift 2. The laser sensor 20 is mounted on the roof 5a of the vehicle body 5 via a mounting bracket 26, for example. The laser sensor 20 detects the distance of objects existing around the forklift 2 by irradiating laser light around the forklift 2 and receiving reflected light of the laser light, thereby acquiring point group data. The point group is a collection of reflection points of the laser light.

[0056] The laser sensor 20 is a first laser sensor that detects the distance to the cargo bed 18 by irradiating a laser toward the cargo bed 18 of the truck 17 and receiving the reflected light of the laser. The irradiation range of the laser light of the laser sensor 20 in the horizontal direction is 360 degrees. The irradiation range of the laser light of the laser sensor 20 in the vertical direction is a predetermined angle θ0 (refer to Fig.10 ). As the laser sensor, for example, 3D LIDAR or the like is used.

[0057] The map storage unit 21 stores map data of the area where the forklift 2 travels. The map data includes buildings, pillars, racks, walls, etc. The map data is created in advance using the laser sensor 20 .

[0058] like Figure 2 As shown, the laser sensors 22 are mounted on both sides of the forklift 2 (at Figure 2Only the left side is shown in the figure). The laser sensor 22 is mounted, for example, on the outer side surface 27a of the mounting column member 27 erected on the vehicle body 5. The laser sensor 22 detects the distance of an object existing on the side of the forklift 2 by irradiating a laser toward the side of the forklift 2 and receiving the reflected light of the laser, thereby acquiring point cloud data.

[0059] The laser sensor 22 is configured to pass through the existing pallet 15A (see FIG. 1 ) that has been loaded on the cargo bed 18 of the truck 17. Figure 6 to Figure 9 ) A second laser sensor that irradiates laser light and receives reflected light from the laser to detect the distance to the existing tray 15A.

[0060] The irradiation ranges of the laser light of the laser sensor 22 in the horizontal direction and the vertical direction are respectively predetermined angles θ1 and θ2 (see Figure 6 ). The predetermined angle θ1 is an angle at which the laser light emitted from the laser sensor 22 illuminates the entire front surface 15a of the existing pallet 15A when the forklift 2 is located in front of the existing pallet 15A. The horizontal irradiation range of the laser light of the laser sensor 22 is narrower than the horizontal irradiation range of the laser light of the laser sensor 20. As the laser sensor 22, for example, a 3D LIDAR or the like is used.

[0061] The travel drive unit 23 is a drive unit that travels the forklift 2. Although not shown, the travel drive unit 23 includes, for example, a travel motor that rotates the rear wheels 8 as drive wheels and a steering motor that steers the front wheels 7 as steering wheels.

[0062] The cargo handling drive unit 24 is a drive unit that moves the fork 12. The cargo handling drive unit 24 is a drive unit that operates the cargo handling hydraulic actuators such as the lift cylinder 13 and the reach cylinder 14.

[0063] The controller 25 is composed of a CPU, a RAM, a ROM, an input / output interface, etc. The controller 25 has a self-position estimating unit 30, an initial travel control unit 31, a pallet presence determination unit 32, a cargo platform edge position detection unit 33, an initial loading position calculation unit 34, a pallet detection travel control unit 35, a pallet position detection unit 36, a loading position calculation unit 37, and a loading control unit 38.

[0064] The self-position estimating unit 30 estimates the self-position of the forklift 2 based on the point group data of the laser sensor 20 and the map data stored in the map storage unit 21. Specifically, the self-position estimating unit 30 estimates the self-position of the forklift 2 by matching the point group data of the laser sensor 20 with the map data using, for example, the SLAM (simultaneous localization and mapping) method. SLAM is a self-position estimating technology that estimates the self-position using sensor data and map data.

[0065] When the initial travel control unit 31 determines whether the pallet 15 is loaded on the cargo bed 18 of the truck 17, the initial travel control unit 31 controls the travel drive unit 23 so as to cause the forklift 2 to travel based on the self-position of the forklift 2 estimated by the self-position estimating unit 30. At this time, the initial travel control unit 31 causes the forklift 2 to travel along the front-rear direction of the truck 17 on one side of the truck 17 (see Figure 5 The travel drive unit 23 is controlled in the manner of (a)).

[0066] The pallet presence determination unit 32 determines whether or not there is an existing pallet 15A already placed on the cargo bed 18 of the truck 17 based on the point cloud data of the laser sensor 20 .

[0067] When the pallet presence determination unit 32 determines that there is no existing pallet 15A on the cargo bed 18 of the truck 17, the cargo bed edge position detection unit 33 detects the position of the side edge 18b on the loading side of the cargo bed 18 based on the point group data of the laser sensor 20. The side edge 18b of the cargo bed 18 is an edge in the width direction of the cargo bed 18, and extends in the front-rear direction of the truck 17. The side edge 18b on the loading side of the cargo bed 18 is the side edge 18b on the side of the cargo bed 18 where the forklift 2 is located.

[0068] The cargo bed edge position detector 33 cooperates with the laser sensor 20 to form a cargo bed detection unit that detects the position of the edge of the cargo bed 18 on the loading side when the pallet presence determination unit 32 determines that there is no existing pallet 15A on the cargo bed 18 .

[0069] Figure 3 2 is a flowchart showing the steps of the cargo bed edge position detection process performed by the cargo bed edge position detection unit 33. Figure 3 In the process, the cargo bed edge position detection unit 33 first obtains the point cloud data of the laser sensor 20 (first laser sensor) (step S101).

[0070] Next, the cargo bed edge position detection unit 33 extracts a point group representing the loading surface 18a of the cargo bed 18 of the truck 17 based on the point group data of the laser sensor 20 (step S102). The loading surface 18a is a surface on which the pallet 15 is loaded on the cargo bed 18. Next, the cargo bed edge position detection unit 33 extracts a point group representing the side edge 18b on the loading side of the cargo bed 18 from the point group representing the loading surface 18a of the cargo bed 18 (step S103).

[0071] Next, the cargo bed edge position detection unit 33 calculates the straight line L (refer to Figure 5(a)) (step S104). Thus, the position of the side edge 18b of the cargo bed 18 on the loading side is obtained.

[0072] Return to Figure 1 The initial loading position calculation unit 34 calculates the initial loading position P0 (refer to Figure 5 The initial loading position P0 is a loading position where the first loading target pallet 15B (the first loading target pallet 15B) is loaded on the cargo platform 18 .

[0073] The initial loading position P0 is a position where the front surface 15a of the pallet 15 is slightly away from the side edge 18b on the loading side of the cargo bed 18 at the front end of the cargo bed 18 of the truck 17 (inner side in the width direction). The initial loading position P0 may also be a position where the front surface 15a of the pallet 15 is aligned with the side edge 18b on the loading side of the cargo bed 18 at the front end of the cargo bed 18 of the truck 17.

[0074] When the pallet presence determination unit 32 determines that there is an existing pallet 15A on the cargo bed 18 of the truck 17, the pallet detection travel control unit 35 controls the travel drive unit 23 so that the forklift 2 travels to the front of the existing pallet 15A. At this time, the pallet detection travel control unit 35 drives the forklift 2 to the front of the existing pallet 15A on the rear side of the cargo bed 18 of the truck 17.

[0075] The pallet detection travel control unit 35 stops the forklift 2 in a state in which the forklift 2 is lateral to the existing pallet 15A (see Figure 6 The travel drive unit 23 is controlled in the manner of (a)). At this time, the pallet detection travel control unit 35 stops the forklift 2 at a position where the laser sensor 22 faces the center portion in the width direction of the existing pallet 15A.

[0076] When the pallet presence determination unit 32 determines that there is an existing pallet 15A on the cargo bed 18 of the truck 17, the pallet position detection unit 36 ​​detects the position of the existing pallet 15A placed on the cargo bed 18 based on the point group data of the laser sensor 22. At this time, the pallet position detection unit 36 ​​detects the position of the existing pallet 15A placed on the rear side of the cargo bed 18. The pallet position detection unit 36 ​​detects the position coordinates and the inclination angle of the existing pallet 15A as the position of the existing pallet 15A.

[0077] The pallet position detector 36 cooperates with the laser sensor 22 to constitute a pallet detector that detects the position of the existing pallet 15A when the pallet presence determination unit 32 determines that the existing pallet 15A exists on the cargo platform 18 .

[0078] Figure 4 4 is a flowchart showing the steps of the tray position detection process performed by the tray position detection unit 36. Figure 4 In the process, the tray position detection unit 36 ​​first obtains the point cloud data of the laser sensor 22 (second laser sensor) (step S111).

[0079] Next, the pallet position detection unit 36 ​​extracts a point group representing the front surface 15a of the existing pallet 15A based on the point group data of the laser sensor 22 (step S112). Next, the pallet position detection unit 36 ​​calculates the plane equation of the front surface 15a of the existing pallet 15A using a robust estimation method such as RANSAC or a least square method (step S113).

[0080] Next, the pallet position detector 36 calculates the position coordinates and the tilt angle of the existing pallet 15A relative to the forklift 2 by a known method using the plane equation of the front surface 15a of the existing pallet 15A (step S114). The position coordinates of the existing pallet 15A relative to the forklift 2 are the three-dimensional position coordinates of the center of the front surface 15a of the existing pallet 15A relative to the laser sensor 22. The tilt angle of the existing pallet 15A relative to the forklift 2 is the yaw angle, pitch angle, and roll angle of the existing pallet 15A relative to the laser sensor 22. Thus, the position of the existing pallet 15A is obtained.

[0081] Return to Figure 1 The loading position calculation unit 37 calculates the next loading position P (refer to the loading position P) of the loading target pallet 15B to be loaded on the cargo platform 18 of the truck 17 based on the position of the existing pallet 15A detected by the pallet position detection unit 36. Figure 7 and Figure 8 The next loading position P is a loading position for loading the second and subsequent loading target pallets 15B on the cargo platform 18. The next loading position P is a position adjacent to the rear side of the existing pallet 15A placed at the rearmost side on the cargo platform 18.

[0082] The loading position calculation unit 37 calculates a position that is offset by the width W of the existing pallet 15A toward the rear side of the truck 17 relative to the existing pallet 15A as the next loading position P. In other words, the loading position calculation unit 37 calculates a position that is offset by the width W of the existing pallet 15A in the left-right direction relative to the existing pallet 15A as the next loading position P. The width W of the loading target pallet 15B is equal to the width W of the existing pallet 15A.

[0083] The loading control unit 38 controls the travel drive unit 23 and the cargo loading and unloading drive unit 24 so that the loading target pallet 15B is loaded at the initial loading position P0 calculated by the initial loading position calculation unit 34 and the next loading position P calculated by the loading position calculation unit 37 .

[0084] That is, the loading control unit 38 controls the travel drive unit 23 and the cargo loading and unloading drive unit 24 in such a manner that the first loading object pallet 15B (the first loading object pallet 15B) is loaded at the initial loading position P0 calculated by the initial loading position calculation unit 34, and controls the travel drive unit 23 and the cargo loading and unloading drive unit 24 in such a manner that the second and subsequent loading object pallets 15B are loaded at the next loading position P calculated by the loading position calculation unit 37.

[0085] Specifically, the loading control unit 38 controls the driving unit 23 for traveling so that the forklift 2 travels to a pallet placement location (not shown) near the truck 17 based on the self-position of the forklift 2 estimated by the self-position estimating unit 30, and then controls the cargo handling driving unit 24 so that the fork 12 holds the pallet 15. Then, the loading control unit 38 controls the driving unit 23 for traveling so that the forklift 2 travels to a target position based on the self-position estimating unit 30, and then controls the cargo handling driving unit 24 so that the fork 12 descends. The target position is a position where the pallet 15 held by the fork 12 reaches the initial loading position P0 and the next loading position P.

[0086] In the loading control device 1 as described above, when the first tray 15 (the first tray 15) is loaded, Figure 5 As shown in (a), the forklift 2 moves backward from the rear side to the front side of the truck 17 on the left side of the truck 17. During the travel of the forklift 2, the laser sensor 20 irradiates the cargo bed 18 of the truck 17 with laser light, thereby acquiring point group data of the laser sensor 20.

[0087] Then, based on the point group data of the laser sensor 20 , the position of the left side edge 18 b of the cargo platform 18 is detected, and the initial loading position P0 of the first loading target pallet 15B on the cargo platform 18 is calculated.

[0088] Then, the forklift 2 moves to the pallet placement location (not shown) to pick up the loading pallet 15B. Specifically, the laser sensor 22 irradiates the laser toward the loading pallet 15B, obtains the point group data of the laser sensor 22, and detects the position of the loading pallet 15B. Then, after the forklift 2's forward extension cylinder 14 moves forward to insert the fork 12 into the fork hole 16 of the loading pallet 15B, the loading pallet 15B is held by the fork 12.

[0089] In this state, if Figure 5 As shown in (b) of FIG. 8 , after the forklift 2 travels to the target position corresponding to the initial loading position P0 , the fork 12 is lowered to place the loading target pallet 15B at the initial loading position P0 .

[0090] Next, when loading the second tray 15, Figure 6 As shown in FIG. 1 , the forklift 2 travels to a position close to the front surface 15a of the existing pallet 15A placed at the initial loading position P0. At this time, the forklift 2 stops in a state of being horizontal with respect to the existing pallet 15A placed at the initial loading position P0. In this state, the laser sensor 22 irradiates the existing pallet 15A with laser light, thereby acquiring point cloud data of the laser sensor 22.

[0091] Then, based on the point group data of the laser sensor 22, the position coordinates and the inclination angle of the existing pallet 15A relative to the forklift 2 are calculated. Figure 7 As shown, the next loading position P of the second loading target pallet 15B on the cargo platform 18 is calculated based on the position coordinates and the inclination angle of the existing pallet 15A.

[0092] Here, if Figure 7 As shown in (a) of FIG. 1 , the next loading position P of the second loading target pallet 15B is a position offset toward the rear side of the truck 17 by the width W of the pallet 15 relative to the first pallet 15 which is the existing pallet 15A.

[0093] In addition, if Figure 7 As shown in (b), when the first pallet 15 is tilted in the pitch direction by the action of the suspension of the truck 17, the next loading position P is obtained, which is offset by the width W of the pallet 15 to the rear side of the truck 17 relative to the first pallet 15, in accordance with the tilt angle of the first pallet 15 in the pitch direction. In addition, although not particularly shown in the figure, when the pallet 15 is tilted in the yaw direction, the next loading position P is obtained, which is offset by the width W of the pallet 15 to the rear side of the truck 17 relative to the first pallet 15, in accordance with the tilt angle of the first pallet 15 in the yaw direction.

[0094] Then, if Figure 8 As shown in FIG. 1 , the forklift 2 picks up the loading target pallet 15B placed at the pallet placement location in the same manner as described above, and then travels to the target position corresponding to the next loading position P. Fig. 9 As shown in FIG. 1 , the loading target pallet 15B is placed at the next loading position P by lowering the fork 12 .

[0095] Then, the third and subsequent pallets 15 are loaded in sequence. At this time, the next loading position P of the third and subsequent loading target pallets 15B is a position offset to the rear of the truck 17 by the width W of the pallet 15 relative to the existing pallet 15A at the rear side of the cargo bed 18 of the truck 17.

[0096] However, in order to detect the position of the cargo platform 18 of the truck 17 by the laser sensor 20, the forklift 2 needs to travel around the cargo platform 18 to a certain extent. In addition, since the laser sensor 20 is arranged on the upper surface of the vehicle body 5 of the forklift 2, Fig.10 As shown in (a), when the forklift 2 is too close to the truck 17, the side edge 18b of the loading side of the cargo platform 18 will be out of the vertical irradiation range (predetermined angle θ0) of the laser of the laser sensor 20 (see E in the figure). In this case, since the position of the side edge 18b of the loading side of the cargo platform 18 cannot be detected, the initial loading position P0 of the pallet 15 cannot be calculated.

[0097] In order to detect the position of the side edge 18b of the loading side of the cargo platform 18, as shown in FIG. Fig.10 As shown in (b), the forklift 2 needs to be driven at a certain distance D from the truck 17 so that the side edge 18b of the loading side of the cargo platform 18 enters the vertical irradiation range of the laser of the laser sensor 20. However, in this case, it is difficult to detect the side edge 18b of the loading side of the cargo platform 18 in a narrow passage or a factory with a narrow layout.

[0098] In order to solve such a problem, in the present embodiment, when it is determined that there is an existing pallet 15A already loaded on the cargo platform 18 of the truck 17, the position of the existing pallet 15A is detected. And based on the position of the existing pallet 15A, the next loading position P of the loading target pallet 15B to be loaded on the cargo platform 18 is calculated. At this time, the position adjacent to the existing pallet 15A in the left-right direction on the cargo platform 18 is calculated as the next loading position P. And the forklift 2 is controlled so that the loading target pallet 15B is loaded at the next loading position P. In this way, when there is an existing pallet 15A already loaded on the cargo platform 18, the next loading position P of the loading target pallet 15B is calculated based on the position of the existing pallet 15A. Therefore, it is not necessary to drive the forklift 2 around the cargo platform 18 to detect the cargo platform 18 in order to calculate the next loading position P of the loading target pallet 15B. As a result, when the forklift 2 loads the pallet 15 on the cargo platform 18, the travel distance of the forklift 2 is shortened. As a result, the time required for loading the pallet 15 can be shortened.

[0099] In addition, in the present embodiment, the laser sensor 22 is mounted on the side of the forklift 2, so when the forklift 2 is in a state of being horizontal with respect to the cargo platform 18, it is possible to irradiate the laser toward the existing pallet 15A placed on the cargo platform 18 to detect the position of the existing pallet 15A. In this case, when the forklift 2 is brought close to the cargo platform 18, the entire front surface 15a of the existing pallet 15A is likely to enter the irradiation range of the laser of the laser sensor 22. Therefore, the position of the existing pallet 15A can be detected even in a narrow passage or a narrow factory.

[0100] In addition, in the present embodiment, the position coordinates and the tilt angle of the existing pallet 15A are detected as the position of the existing pallet 15A. Therefore, even if the existing pallet 15A is placed on the cargo platform 18 in a tilted state due to the weight of the cargo placed on the existing pallet 15A, the next loading position P of the loading target pallet 15B can be appropriately calculated based on the position coordinates and the tilt angle of the existing pallet 15A.

[0101] In addition, in the present embodiment, a position offset in the left-right direction from the existing pallet 15A by the width W of the existing pallet 15A is calculated as the next loading position P. Therefore, the pallets 15 adjacent in the left-right direction are loaded onto the cargo platform 18 without any gaps therebetween. Therefore, a large number of pallets 15 can be loaded onto the cargo platform 18.

[0102] In addition, in the present embodiment, when it is determined that there is no existing pallet 15A on the cargo platform 18, the position of the side edge 18b on the loading side of the cargo platform 18 is detected. Then, the initial loading position P0 of the first loading target pallet 15B is calculated based on the position of the side edge 18b on the loading side of the cargo platform 18. Therefore, even in a state where there is no existing pallet 15A on the cargo platform 18, the first loading target pallet 15B is loaded at an appropriate position on the cargo platform 18.

[0103] In addition, in the present embodiment, the laser sensor 20 is mounted on the upper part of the forklift 2, so that the laser sensor 20 acquires a wide range of point group data around the forklift 2. Therefore, the position of the side edge 18b of the loading side of the cargo bed 18 can be detected with good accuracy. In addition, the laser sensor 20 can also be used to estimate the position of the forklift 2 itself or to detect obstacles existing around the forklift 2.

[0104] In addition, in the present embodiment, the irradiation range of the laser light of the laser sensor 22 in the horizontal direction is narrower than the irradiation range of the laser light of the laser sensor 20 in the horizontal direction. Therefore, the laser sensor 22, which is cheaper than the laser sensor 20, can be used. In addition, the laser sensor 22 obtains point group data with a higher density than the laser sensor 20, so the position of the existing pallet 15A placed on the cargo platform 18 can be detected with high accuracy.

[0105] In addition, in the present embodiment, a position offset to the rear side of the truck 17 by the width W of the existing pallet 15A relative to the existing pallet 15A placed on the cargo bed 18 of the truck 17 is calculated as the next loading position P, but the present invention is not particularly limited to this manner. For example, a position offset to the rear side of the truck 17 by a predetermined value greater than the width W of the pallet 15 relative to the existing pallet 15A may be calculated as the next loading position P. In this case, a gap is created between two adjacent pallets 15 in the left-right direction, so that the pallet 15 with the cargo can be loaded onto the cargo bed 18 even when the cargo on the pallet 15 protrudes from the pallet 15 in the left-right direction.

[0106] Fig.11 FIG. 1 is a block diagram showing the structure of a loading control device according to another embodiment of the present invention. Fig.11 In the embodiment, the loading control device 1A is mounted on a forklift 2A having two pairs (four) of left and right forks 12 (see Fig.12 ). The forklift 2A can simultaneously hold two pallets 15 by the two pairs of left and right forks 12. In a state where the two pallets 15 are simultaneously held by the two pairs of left and right forks 12, the two pallets 15 are in contact with each other.

[0107] The loading control device 1A includes a controller 25A instead of the controller 25 of the above embodiment. The controller 25A includes the above-mentioned own position estimation unit 30, the above-mentioned initial travel control unit 31, the pallet presence determination unit 32A, the above-mentioned cargo platform edge position detection unit 33, the initial loading position calculation unit 34A, the pallet detection travel control unit 35A, the pallet position detection unit 36A, the loading position calculation unit 37A, and the loading control unit 38A.

[0108] The pallet presence determination unit 32A determines whether or not there are two existing pallets 15A that are already placed side by side on the cargo bed 18 of the truck 17 .

[0109] When the pallet presence determination unit 32A determines that there are no two existing pallets 15A on the cargo bed 18 of the truck 17, the initial loading position calculation unit 34A calculates the initial loading position P0 of the two loading object pallets 15B in the cargo bed 18 based on the position of the side edge 18b of the loading side of the cargo bed 18 detected by the above-mentioned cargo bed edge position detection unit 33.

[0110] When the pallet presence determination unit 32A determines that there are two existing pallets 15A on the cargo bed 18 of the truck 17, the pallet detection driving control unit 35A Fig.12 As shown, the travel drive unit 23 is controlled so that the forklift 2A travels to the front of any one of the two existing pallets 15A placed on the cargo bed 18 of the truck 17 .

[0111] like Fig.12 As shown in (a), when the forklift 2 is driven to the front of the existing pallet 15A on the left, the pallet detection driving control unit 35A stops the forklift 2 in a horizontal position relative to the existing pallet 15A on the left so that the laser sensor 22 faces the center of the width direction of the existing pallet 15A on the left. Fig.12 As shown in (b), when the forklift 2 is driven to the front of the existing pallet 15A on the right side, the travel control unit 35A for pallet detection stops the forklift 2 in a horizontal state relative to the existing pallet 15A on the right side so that the laser sensor 22 is directed toward the center portion in the width direction of the existing pallet 15A on the right side.

[0112] When the pallet presence determination unit 32A determines that there are two existing pallets 15A on the cargo bed 18 of the truck 17 , the pallet position detection unit 36A detects the position of any one of the two existing pallets 15A placed on the cargo bed 18 based on the point group data of the laser sensor 22 .

[0113] The pallet position detector 36A cooperates with the laser sensor 22 to form a pallet detector that detects the position of one of the two existing pallets 15A when the pallet presence determination unit 32A determines that there are two existing pallets 15A on the cargo platform 18 .

[0114] The loading position calculation unit 37A calculates the next loading position P (see FIG. 1 ) of the loading target pallet 15B on the cargo bed 18 of the truck 17 based on the position of one of the two existing pallets 15A detected by the pallet position detection unit 36A. Fig.13 The next loading position P is a position adjacent to the rear side of the two existing pallets 15A placed on the rearmost side of the cargo platform 18 .

[0115] When the position of the existing pallet 15A on one of the two existing pallets 15A is detected, the loading position calculation unit 37A calculates a position that is offset to the other left or right side by 2.5 times the width W of the existing pallet 15A relative to the existing pallet 15A on one of the two existing pallets 15A as the next loading position P. When the position of the existing pallet 15A on the other left or right side is detected, the loading position calculation unit 37A calculates a position that is offset to the other left or right side by 1.5 times the width W of the existing pallet 15A relative to the existing pallet 15A on the other left or right side as the next loading position P.

[0116] That is, when the position of the left existing tray 15A of the two existing trays 15A is detected, Fig.13As shown in (a), a position offset to the right (the rear side of the truck 17) by 2.5 times the width W of the pallet 15 relative to the existing pallet 15A on the left is calculated as the next loading position P.

[0117] On the other hand, when the position of the right existing tray 15A of the two existing trays 15A is detected, as shown in FIG. Fig.13 As shown in (b), a position offset to the right (to the rear of the truck 17) by 1.5 times the width W of the pallet 15 relative to the existing pallet 15A on the right is calculated as the next loading position P.

[0118] The loading control unit 38A controls the travel drive unit 23 and the cargo loading and unloading drive unit 24 in such a manner that the first (first group) two loading object pallets 15B are simultaneously loaded at the initial loading position P0 calculated by the initial loading position calculation unit 34A, and controls the travel drive unit 23 and the cargo loading and unloading drive unit 24 in such a manner that the two loading object pallets 15B after the second group are simultaneously loaded at the next loading position P calculated by the loading position calculation unit 37A.

[0119] When the loading control unit 38A is executed, when the loading target pallet 15B is picked up at the pallet placement location (not shown), the position of the loading target pallet 15B is detected using the laser sensor 22 as described above. Fig.14 As shown in FIG. 1 , the loading target trays 15B are arranged in two rows in the left-right direction.

[0120] Here, when the position of the left loading pallet 15B is detected, the forklift 2 is offset to the right by 1 / 2 of the width W of the loading pallet 15B relative to the left loading pallet 15B. When the position of the right loading pallet 15B is detected, the forklift 2 is offset to the left by 1 / 2 of the width W of the loading pallet 15B relative to the right loading pallet 15B. Therefore, the forklift 2 moves toward the middle G between the two loading pallets 15B, and the four forks 12 are simultaneously inserted into the fork holes 16 of the two loading pallets 15B.

[0121] In the present embodiment as described above, two loading target pallets 15B are loaded simultaneously by the forklift 2A having four forks 12 so as to be adjacent to two existing pallets 15A which are already arranged side by side on the cargo bed 18 of the truck 17 in the left-right direction. Therefore, a plurality of pallets 15 can be loaded on the cargo bed 18 efficiently.

[0122] In addition, in the present embodiment, when the position of the existing pallet 15A on one side of the left or right is detected, a position shifted toward the other side of the left or right by 2.5 times the width W of the existing pallet 15A is calculated as the next loading position P, and when the position of the existing pallet 15A on the other side of the left or right is detected, a position shifted toward the other side of the left or right by 1.5 times the width W of the existing pallet 15A is calculated as the next loading position P. Therefore, when the position of the existing pallet 15A on either side of the left or right is detected, the pallets 15 adjacent to each other in the left and right direction are loaded onto the cargo platform 18 without any gap. Therefore, a large number of pallets 15 can be loaded onto the cargo platform 18.

[0123] In addition, in the present embodiment, the initial loading position P0 and the next loading position P are calculated such that the pallets 15 adjacent to each other in the left-right direction are loaded onto the cargo bed 18 of the truck 17 without any gap, but the present invention is not particularly limited to this manner. The initial loading position P0 and the next loading position P may be calculated such that a gap is formed between two pallets 15 adjacent to each other in the left-right direction. In this case, a gap is formed between the two pallets 15 while the two pairs of left and right forks 12 simultaneously hold the two pallets 15.

[0124] In the present embodiment, the forklift 2A includes two pairs (four pieces) of forks 12 on the left and right sides. However, the forklift 2A is not particularly limited to this embodiment, and may include three pairs (six pieces) or more of forks 12 on the left and right sides.

[0125] The embodiments of the present invention have been described above, but the present invention is not limited to the above embodiments. For example, in the above embodiments, the laser sensor 20 is used to determine whether there is an existing pallet 15A already loaded on the cargo bed 18 of the truck 17, but the present invention is not particularly limited to this method. For example, a camera that captures the surroundings of the forklift 2, 2A may be used to determine whether there is an existing pallet 15A already loaded on the cargo bed 18 of the truck 17.

[0126] In addition, in the above-mentioned embodiment, the pallets 15 are sequentially loaded onto the cargo bed 18 of the truck 17 from the front side toward the rear side, but the present invention is not particularly limited to this method. The pallets 15 may be sequentially loaded onto the cargo bed 18 of the truck 17 from the rear side toward the front side. In this case, the first pallet 15 is loaded onto the rear end of the cargo bed 18. In addition, the loading direction of the pallets 15 may also be instructed by the upper system.

[0127] In addition, in the above-mentioned embodiment, the first pallet 15 is loaded at the front end or the rear end of the cargo bed 18 of the truck 17, but the present invention is not particularly limited to this method. For example, the first pallet 15 may be loaded at the center of the cargo bed 18 of the truck 17 in the front-rear direction, and then the pallet 15 may be loaded toward one side of the front and rear of the truck 17, and then the pallet 15 may be loaded toward the other side of the front and rear of the truck 17. The loading direction of the pallet 15 in this case may also be instructed by the upper system.

[0128] In addition, in the above-mentioned embodiment, the widths W of the pallets 15 are all equal, but the present invention is not particularly limited to this embodiment. As long as the width W of the next loading object pallet 15B is known, a plurality of pallets 15 having different widths W may be sequentially loaded onto the cargo bed 18 of the truck 17. In addition, the width information of the next loading object pallet 15B may be obtained from the upper system.

[0129] Furthermore, in the above-described embodiment, the pallet 15 is loaded on the cargo bed 18 of the truck 17 , but the cargo bed on which the pallet 15 is loaded is not particularly limited to the truck 17 , and may be, for example, a truck berth or the like.

[0130] Furthermore, in the above-described embodiment, the forklifts 2 and 2A are reach-type forklifts, but they may of course be counter-type forklifts.

Claims

1. A loading control device for loading a pallet onto a cargo platform by a forklift having a plurality of forks for holding the pallet, characterized in that: have: a pallet presence determination unit for determining whether there is an existing pallet already placed on the cargo platform; a pallet detection unit for detecting a position of the existing pallet when the pallet presence determination unit determines that the existing pallet exists on the cargo platform; a loading position calculating unit that calculates a loading position of a loading target pallet to be loaded next on the cargo platform based on the position of the existing pallet detected by the pallet detecting unit; and a loading control unit configured to control the forklift so that the loading target pallet is loaded at the loading position calculated by the loading position calculation unit, The loading position calculation unit calculates a position adjacent to the existing pallet in the left-right direction on the cargo platform as the loading position.

2. The loading control device according to claim 1, wherein: The pallet detection unit includes a laser sensor mounted on a side of the forklift and configured to detect the distance of the existing pallet by irradiating laser light toward the existing pallet and receiving reflected light of the laser light, and detects the position of the existing pallet based on point group data of the laser sensor.

3. The loading control device according to claim 1 or 2, wherein: The pallet detection unit detects the position coordinates and the inclination angle of the existing pallet as the position of the existing pallet.

4. The loading control device according to any one of claims 1 to 3, wherein: The width of the loading object pallet is equal to the width of the existing pallet. The loading position calculation unit calculates a position that is offset in the left-right direction from the existing pallet by an amount corresponding to a width of the existing pallet as the loading position.

5. The loading control device according to any one of claims 1 to 4, wherein: Also available: a cargo platform detection unit that detects a position of an edge of the cargo platform on the loading side when the pallet presence determination unit determines that the existing pallet does not exist on the cargo platform; and an initial loading position calculating unit that calculates a loading position of a loading target pallet that is first loaded on the cargo platform based on a position of an edge of the cargo platform on the loading side detected by the cargo platform detecting unit, The loading control unit controls the forklift so that the loading target pallet is loaded at the loading position calculated by the initial loading position calculation unit and the loading position calculation unit.

6. The loading control device according to claim 5, wherein: The cargo bed detection unit has a first laser sensor mounted on the upper part of the forklift and detects the distance to the cargo bed by irradiating a laser toward the cargo bed and receiving reflected light of the laser, and detects the position of the edge of the loading side of the cargo bed based on the point group data of the first laser sensor.

7. The loading control device according to claim 6, wherein: The pallet detection unit includes a second laser sensor mounted on a side of the forklift and configured to detect a distance to the existing pallet by irradiating a laser toward the existing pallet and receiving reflected light of the laser, and detects a position of the existing pallet based on point group data of the second laser sensor.

8. The loading control device according to claim 7, wherein: The irradiation range of the laser beam of the second laser sensor in the horizontal direction is narrower than the irradiation range of the laser beam of the first laser sensor in the horizontal direction.

9. The loading control device according to any one of claims 1 to 8, wherein: The forklift has four forks in a manner capable of holding two pallets at the same time. The pallet presence determination unit determines whether there are two existing pallets that are placed side by side on the cargo platform. The pallet detection unit detects the position of one of the two existing pallets when the pallet presence determination unit determines that the two existing pallets exist. The loading position calculation unit calculates the loading positions of the two loading target pallets to be loaded on the cargo platform next based on the position of either of the two existing pallets detected by the pallet detection unit. The loading control unit controls the forklift so that the two loading target pallets are simultaneously loaded at the loading positions calculated by the loading position calculation unit.

10. The loading control device according to claim 9, wherein: The width of the loading object pallet is equal to the width of the existing pallet. When the position of the existing pallet on one of the two existing pallets is detected, the loading position calculation unit calculates a position that is offset to the other left or right side by 2.5 times the width of the existing pallet relative to the existing pallet on one of the two existing pallets as the loading position. When the position of the existing pallet on the other left or right side is detected, the loading position calculation unit calculates a position that is offset to the other left or right side by 1.5 times the width of the existing pallet relative to the existing pallet on the other left or right side as the loading position.

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