IMPURITY SEPARATION SYSTEMS, IMPURITY SEPARATION METHODS, AND COMPUTER-READABLE RECORDING DEVICES STORING PROGRAMS

Abstract

The invention proposes a system for separating impurities, a method for separating impurities, and a computer-readable recording device that stores programs, each capable of reducing the amount of scrap to be removed along with impurities in a scrap pile. The system for separating impurities (1) consists of: a transport device (20) configured to lift and transport a portion of the scrap pile (SS); an impurity detection device in the transported scrap (30) configured to detect impurities (D) in the scrap pile (SS) lifted by the transport device (20); and the control device (40) is configured so that, when the impurity detection unit in the transported scrap (30) detects impurity (D) in the lifted scrap pile (SS), determines the location of the impurity in the lifted scrap pile (SS) and controls the transport device (20) to drop the scrap (S) and impurity (D) in the lifted scrap pile (SS) to different areas based on the determined location of the impurity (D).

Description

Foreign matter separation system, foreign matter separation method, program, and computer-readable recording medium storing the program

[0001] The present invention relates to a foreign matter separation system, a foreign matter separation method, a program, and a computer-readable recording medium storing the program, which separates foreign matter contained in a group of scrap from the scrap.

[0002] In steelworks, increased use of iron-based scrap as a raw material is desired in order to manufacture steel products while reducing the environmental impact. Generally, a group of iron-based scraps, which is made up of multiple iron-based scraps, contains foreign matter such as materials of different types or sizes from the iron-based scrap, taboo materials, sealed materials, and hazardous materials that are undesirable when using the iron-based scrap.

[0003] For example, a steel scrap inspection method disclosed in Patent Document 1 has been proposed as a method for automatically detecting foreign objects contained in steel scrap piles. The steel scrap inspection method disclosed in Patent Document 1 is a method for inspecting steel scrap piles piled on the back of a truck parked at a truck stop location in cooperation with steel scrap yard equipment. This inspection method includes an imaging step of imaging the steel scrap piles piled on the back of a truck parked at a truck stop location, an inspection step in which a detection device uses a trained model to determine whether or not a taboo object that is likely to be contained in the steel scrap is captured in the image data, and if a taboo object is determined to be captured, an inspection step in which the steel scrap pile captured in the image data is inspected by having an operator remove the taboo object, and a moving step in which the inspected steel scrap pile captured in the image data is moved from the back of the truck to a storage area for inspected steel scrap using a lift magnet or the like, and these steps are repeated until the scrap pile is removed from the truck back. This allows for the efficient detection of prohibited materials from among the piles of iron scrap piled up on the back of a truck.

[0004] Furthermore, a foreign object detection device and a foreign object removal device have been proposed for detecting and removing foreign objects mixed in iron-based scrap, for example, as disclosed in Patent Document 2. The foreign object detection device disclosed in Patent Document 2 includes an object image acquisition unit that acquires an image of an object containing iron-based scrap, and an image discrimination unit that detects foreign objects by distinguishing between iron-based scrap and other foreign objects based on the object image. The foreign object removal device disclosed in Patent Document 2 also includes the foreign object detection device, a foreign object position identification unit that identifies the position of the foreign object in real space based on the determination result from the type determination unit, and a foreign object removal unit that removes the foreign object from the object based on the position of the foreign object identified by the foreign object position identification unit. The foreign object removal unit has a gripper that can move in three dimensions relative to the object containing iron-based scrap. This allows the foreign object detection device to accurately detect foreign objects from iron-based scrap mixed in with foreign objects, and also allows the foreign object detection device to remove the foreign object from the object.

[0005] JP 2020-176909 A JP 2021-163078 A

[0006] However, the conventional iron scrap inspection method disclosed in Patent Document 1 and the foreign matter detection device and foreign matter removal device disclosed in Patent Document 2 have the following problems. In the iron scrap inspection method disclosed in Patent Document 1, although the detection device can detect prohibited objects contained in the iron scrap mass, the prohibited objects must be removed manually by an operator. Furthermore, in the foreign matter detection device and foreign matter removal device disclosed in Patent Document 2, although foreign objects can be removed automatically, the gripping part of the foreign matter removal unit makes it difficult to lift only the foreign objects contained in the iron-based scrap mass, and iron-based scrap that is not to be removed may also be lifted and removed together with the foreign objects.

[0007] Therefore, the present invention has been made to solve this conventional problem, and its object is to provide a foreign matter separation system, a foreign matter separation method, a program, and a computer-readable recording medium on which the program is stored, which can reduce the amount of scrap that is removed together with foreign matter from a scrap pile.

[0008] In order to solve the above-mentioned problems, one embodiment of the present invention provides a foreign matter separation system that separates foreign matter contained in a group of scrap from the scrap, and is characterized by comprising: a conveying device that lifts and conveys a portion of the group of scrap; a conveyed scrap foreign matter detection means that detects foreign matter in the group of scrap lifted by the conveying device; and a control device that, when a foreign matter in the group of scrap lifted by the conveyed scrap foreign matter detection means is detected in the group of scrap lifted, identifies the position of the foreign matter in the group of scrap lifted, and controls the conveying device based on the identified position of the foreign matter in the group of scrap lifted to drop the scrap and foreign matter in the group of scrap lifted to different locations, thereby separating the foreign matter contained in the group of scrap from the scrap.

[0009] Another aspect of the present invention provides a foreign matter separation method for separating foreign matter contained in a group of scrap from the scrap, and includes: a lifting step in which a control device controls a conveying device to lift a portion of the group of scrap; a transported scrap foreign matter detection step in which a transported scrap foreign matter detection means detects foreign matter in the group of scrap lifted in the lifting step; a position identification step in which the control device identifies the position of the foreign matter in the group of lifted scrap if a foreign matter is detected in the transported scrap foreign matter detection step; and a separation step in which the control device controls the conveying device to drop the scrap and the foreign matter in the group of lifted scrap to different locations based on the position of the foreign matter in the group of lifted scrap identified in the position identification step, thereby separating the foreign matter contained in the group of scrap from the scrap.

[0010] In addition, a program according to another aspect of the present invention is a program for causing a control device to execute a lifting step of controlling a conveying device to lift a portion of a scrap group; a position identification step of identifying the position of a foreign object in the lifted scrap group when a foreign object in the scrap group lifted in the lifting step is detected by a conveyed scrap foreign object detection means; and a separation step of controlling the conveying device to drop the scrap and the foreign object in the lifted scrap group to different locations based on the position of the foreign object in the lifted scrap group identified in the position identification step, thereby separating the foreign object contained in the scrap group from the scrap.

[0011] In addition, a computer-readable recording medium having a program stored thereon according to another aspect of the present invention is a computer-readable recording medium having a program stored thereon to cause a control device to execute a lifting step of controlling a conveying device to lift a portion of a scrap pile; a position identification step of identifying the position of a foreign object in the lifted scrap pile when a foreign object in the lifted scrap pile is detected by a conveyed scrap foreign object detection means; and a separation step of controlling the conveying device to drop the scrap and the foreign object in the lifted scrap pile to different locations based on the position of the foreign object in the lifted scrap pile identified in the position identification step, thereby separating the foreign object contained in the scrap pile from the scrap.

[0012] According to the foreign matter separation system, foreign matter separation method, program, and computer-readable recording medium storing the program of the present invention, it is possible to reduce the amount of scrap that is removed together with foreign matter from a group of scrap.

[0013] 1 is an overall configuration diagram of a foreign matter separation system according to a first embodiment of the present invention. FIG. 1 is a functional block diagram of the foreign matter separation system shown in FIG. 1. FIG. 2 is a flowchart for explaining the processing flow in the foreign matter separation system shown in FIG. 1. FIG. 3 is a diagram for explaining an example of the hardware configuration of a control device. FIG. 4 is a diagram showing an example of a pre-captured image of a pile of scrap placed on a semi-trailer, captured by a pre-capture device, together with the location where the pile of scrap is lifted by a lifting magnet. FIG. 5 is a diagram showing an example of controlling a lifting magnet as a conveying device to separate foreign matter contained in the pile of scrap from the scrap. FIG. 6 is a diagram showing an example of controlling a grapple as a conveying device to separate foreign matter contained in the pile of scrap from the scrap. FIG. 7 is a diagram showing an example of controlling a shovel as a conveying device to separate foreign matter contained in the pile of scrap from the scrap. FIG. 8 is a functional block diagram of a foreign matter separation system according to a second embodiment of the present invention. FIG. 9 is a flowchart for explaining the processing flow in the foreign matter separation system shown in FIG. 10. FIG. 11 is a diagram showing an example of a pre-captured image of a pile of scrap placed on a semi-trailer, captured by a pre-capture device, together with the location where the pile of scrap is lifted by a lifting magnet, when foreign matter contained in the pile of scrap is separated from the scrap using a foreign matter separation system according to a modified example. 12 is a diagram showing an example of a foreign object separation system according to a modified example, in which a lifting magnet as a conveying device is controlled to separate foreign objects contained in a pile of scrap from the scrap when the foreign objects are in the way and the scrap cannot be lifted. In FIG. 12, the upper side shows the loading platform of the semi-trailer as viewed from above, and the lower side shows the loading platform of the semi-trailer as viewed from the side.

[0014] Hereinafter, embodiments of the present invention will be described with reference to the drawings. The embodiments shown below are examples of devices and methods for embodying the technical concept of the present invention, and the technical concept of the present invention is not limited to the materials, shapes, structures, arrangements, etc. of the components in the embodiments described below. Furthermore, the drawings are schematic. Therefore, it should be noted that the relationships and ratios between thicknesses and planar dimensions may differ from the actual ones, and the drawings may also contain portions where the relationships and ratios of dimensions differ from one another.

[0015] First Embodiment FIG. 1 illustrates the overall configuration of a foreign object separation system according to a first embodiment of the present invention. The foreign object separation system 1 illustrated in FIG. 1 separates foreign objects D contained in a scrap group SS from scrap S. In this embodiment, the scrap group SS is transported to a predetermined location on the bed of a semi-trailer 50. The scrap group SS may contain one or more foreign objects D in addition to multiple pieces of scrap (iron-based scrap) S. Here, the foreign object D generally refers to anything undesirable when using the scrap S, such as objects of a different type or size from the scrap S, prohibited objects, sealed objects, hazardous materials, etc. In this embodiment, the foreign object D includes, for example, objects containing tramp elements such as motors, sealed objects where the air inside may be explosive, oversized items or other unusable objects, and non-metallic ferrous objects such as rubber.

[0016] The scrap S in the scrap group SS placed on the bed of the semi-trailer 50 is separated and transported to a scrap placement area 51, and the foreign matter D in the scrap group SS is transported to a foreign matter placement area 52 by a foreign matter separation system 1. This foreign matter separation system 1 includes a pre-photography device 10, a transport device 20, a transported scrap foreign matter detection means 30, and a control device 40. The pre-photography device 10 is a camera that photographs the scrap group SS placed on the bed of the semi-trailer 50 from above the bed. In other words, the pre-photography device 10 photographs the scrap group SS in advance before a portion of the scrap group SS is lifted by a lifting magnet 21 serving as the transport device 20.

[0017] The transport device 20 lifts and transports a portion of the scrap group SS placed on the bed of the semi-trailer 50, and is a lifting magnet 21 that uses magnetic force to lift and transport the portion of the scrap group SS. The transport device 20 is not limited to the lifting magnet 21, and may be, for example, a grapple as shown in FIG. 7 or a shovel 23 as shown in FIG. 8. The lifting magnet 21 serving as the transport device 20 is movable in both vertical and horizontal directions, as shown in FIG. 1. The lifting magnet 21 moves vertically downward to hold a portion of the scrap group SS, moves vertically upward to lift the held portion of the scrap group SS, and moves horizontally to transport the lifted portion of the scrap group SS.

[0018] The transported scrap foreign matter detection means 30 detects foreign matter D in the scrap group SS lifted by the lifting magnet 21 serving as the transporting device 20 (see Figure 6), and as shown in Figures 1 and 2, is equipped with a photographing device 31 that photographs the scrap group SS lifted by the lifting magnet 21, an image acquisition unit 45 (described later) of the control device 40 that acquires the image photographed by the photographing device 31, and a transported scrap foreign matter detection unit 46 (described later) of the control device 40 that detects foreign matter D in the lifted scrap group SS from the image acquired by the image acquisition unit 45.

[0019] The photographing device 31 is a camera that photographs the scrap group SS lifted by the lifting magnet 21 serving as the conveying device 20. The photographing direction of the scrap group SS by the photographing device 31 may be any direction; for example, the photographed scrap group SS may be photographed from the side or from below. In this embodiment, the photographing device 31 and the pre-photography device 10 are separate cameras, but the same camera may also be used. The photographed image acquisition unit 45 is a component of the control device 40 and acquires the photographed image taken by the photographing device 31.

[0020] The transported scrap foreign matter detection unit 46 is a component of the control device 40, and detects foreign matter D in the lifted scrap group SS from the captured images acquired by the captured image acquisition unit 45. Any method may be used for detecting foreign matter D from the captured images by the transported scrap foreign matter detection unit 46, but in this embodiment, the transported scrap foreign matter detection unit 46 uses a learning model that has been trained on captured images of the scrap group SS containing foreign matter D, and inputs the captured images acquired by the captured image acquisition unit 45 into the learning model to detect foreign matter D in the scrap group SS. In other words, the transported scrap foreign matter detection unit 46 determines whether or not foreign matter D is present in the scrap group SS.

[0021] The control device 40 has a function of controlling the lifting magnet 21 serving as the conveying device 20 to lift a portion of the scrap group SS. The control device 40 also has a function of identifying the position of the foreign object D in the lifted scrap group SS when the conveyed scrap foreign object detection means 30 detects the foreign object D in the lifted scrap group SS. The control device 40 also has a function of controlling the lifting magnet 21 serving as the conveying device 20 to drop the scrap S and the foreign object D in the lifted scrap group SS to different locations based on the identified position of the foreign object D in the lifted scrap group SS, thereby separating the foreign object D contained in the scrap group SS from the scrap S.

[0022] First, the control device 40 includes a preliminary image acquisition unit 41, a preliminary scrap foreign matter detection unit 42, a preliminary position identification unit 43, and a conveyance control unit 44 to achieve the function of controlling the lifting magnet 21 serving as the conveyance device 20 to lift a portion of the scrap group SS. The preliminary image acquisition unit 41 acquires a preliminary captured image G (see FIG. 5 ) captured by the preliminary photography device 10. FIG. 5 shows an example of the preliminary captured image G acquired by the preliminary image acquisition unit 41, together with a location X of the scrap group SS being lifted by the lifting magnet 21.

[0023] The advance scrap foreign object detection unit 42 detects foreign objects D in the scrap group SS before lifting from the advance captured image G acquired by the advance image acquisition unit 41. Any method may be used for detecting foreign objects D from the advance captured image G by the advance scrap foreign object detection unit 42. In this embodiment, the advance scrap foreign object detection unit 42 uses a learning model trained on images of the scrap group SS containing foreign objects D, and inputs the advance captured image G acquired by the advance image acquisition unit 41 into the learning model to detect foreign objects D in the scrap group SS. In other words, the advance scrap foreign object detection unit 42 determines whether or not foreign objects D are present in the scrap group SS. In the example shown in FIG. 5 , two foreign objects D are detected in the scrap group SS.

[0024] Furthermore, when the preliminary scrap foreign object detection unit 42 detects a foreign object D in the scrap group SS before lifting, the preliminary position identification unit 43 identifies the position (position coordinates) of the foreign object D in the scrap group SS before lifting from the preliminary captured image G. In the example shown in Fig. 5, the positions of two foreign objects D are identified in the scrap group SS. When identifying the position of the foreign object D, other information about the foreign object D (such as type, estimated weight, estimated length (size)) may also be identified.

[0025] Furthermore, the conveyance control unit 44 controls the lifting magnet 21 of the conveyance device 20 to lift a portion of the scrap group SS containing the foreign object D based on the position of the foreign object D in the scrap group SS before lifting, as identified by the preliminary position identification unit 43. In this case, the conveyance control unit 44 first moves the lifting magnet 21 horizontally so that the lifting magnet 21 is positioned above the position of the foreign object D in the scrap group SS before lifting, as identified by the preliminary position identification unit 43. Next, the conveyance control unit 44 controls the lifting magnet 21 to move vertically downward to hold a portion of the scrap group SS containing the foreign object D, and then to move the lifting magnet 21 vertically upward to lift the held portion of the scrap group SS. In the example shown in FIG. 5 , the conveyance control unit 44 controls the lifting magnet 21 to lift a portion of the scrap group SS containing the foreign object D at the lifting location X. 5, the lifting magnet 21 is controlled so that the foreign object D is located at the center of the lifting point X, but the lifting magnet 21 may also be controlled so that the foreign object D is located on the outer periphery of the lifting point X. By locating the foreign object D on the outer periphery of the lifting point X, the foreign object D is more likely to appear in the captured image when the scrap group SS lifted by the lifting magnet 21 is photographed by the photographing device 31, and the foreign object D can be easily detected from the captured image.

[0026] At this time, the lifting magnet 21 also lifts up the scrap S other than the foreign object D. If the foreign object D is non-magnetic, it may not be attracted to the magnet of the lifting magnet 21, in which case the foreign object D will be lifted up together with the surrounding scrap S. In this case, a transport device such as a crane that does not rely on magnetic force other than the lifting magnet 21 may be used. Furthermore, when the lifting magnet 21 lifts the scrap group SS, the transport control unit 44 may control the position and magnetic force of the lifting magnet 21 using information other than the position of the foreign object D (such as type, estimated weight, estimated length (size)).

[0027] In addition, the control device 40 is equipped with a position identification unit 47, a foreign object separation control unit 48, and the aforementioned conveying control unit 44 in order to achieve the function of identifying the position of foreign objects D in the aforementioned lifted scrap group SS and the function of separating the foreign objects D contained in the scrap group SS from the scrap S.

[0028] When the transported scrap foreign object detection means 30 (photographing device 31, photographed image acquisition unit 45, and transported scrap foreign object detection unit 46) detects a foreign object D in the lifted scrap group SS, the position identification unit 47 identifies the position of the foreign object D in the lifted scrap group SS from the photographed image acquired by the photographed image acquisition unit 45. In the present embodiment, a portion of the scrap group SS is lifted by the aforementioned transport control unit 44 controlling the lifting magnet 21. Then, when the transported scrap foreign object detection means 30 detects a foreign object D in the scrap group SS lifted by the lifting magnet 21, the position identification unit 47 identifies the position of the foreign object D in the lifted scrap group SS from the photographed image acquired by the photographed image acquisition unit 45. When identifying the position of the foreign object D, other information about the foreign object D (such as type, estimated weight, estimated length (size)) may also be identified.

[0029] Furthermore, the foreign matter separation control unit 48 controls the conveying device 20 to adjust the holding force that maintains the lifted state of the scrap group SS, based on the position of the foreign matter D in the lifted scrap group SS identified by the position identification unit 47. Furthermore, the transport control unit 44 controls the horizontal transport of the lifted scrap group SS by the lifting magnet 21 serving as the conveying device 20, based on the position of the foreign matter D in the lifted scrap group SS identified by the position identification unit 47. The control device 40 then controls the foreign matter separation control unit 48 to adjust the holding force that maintains the lifted state of the scrap group SS by the conveying device 20, and controls the transport of the lifted scrap group SS by the transport control unit 44, thereby separating the foreign matter D included in the scrap group SS from the scrap S.

[0030] 1 and 6, when separating the foreign object D, the foreign object separation control unit 48 controls the holding force (magnetic force) of the lifting magnet 21 of the conveying device 20 based on the position of the foreign object D in the scrap group SS, and the conveyance control unit 44 controls the conveyance of the scrap group SS based on the position of the foreign object D in the scrap group SS. Specifically, the position of the foreign object D in the scrap group SS is determined based on whether the distance d between the foreign object D and the boundary line L between the scrap group SS and the background in the captured image is equal to or less than a predetermined value, as shown in FIG. 6. If the distance d is equal to or less than the predetermined value, the conveyance control unit 44 determines that the foreign object D can be dropped and controls the position of the lifting magnet 21 of the conveying device 20 to move above the foreign object placement location 52. The foreign object separation control unit 48 determines that the foreign object D can be dropped and weakens the holding force (magnetic force) of the lifting magnet 21 of the conveying device 20 to a holding force (magnetic force) that allows the foreign object D to be dropped. As a result, the foreign object D falls and is placed on the foreign object placement area 52. On the other hand, if the distance d is greater than a predetermined value, the transport control unit 44 determines that the scrap S can be dropped and controls the position of the lifting magnet 21 of the transport device 20 to move above the scrap placement area 51, and the foreign object separation control unit 48 determines that the scrap S can be dropped and weakens the holding force (magnetic force) of the lifting magnet 21 of the transport device 20 to a holding force (magnetic force) that allows the scrap S to fall. As a result, the scrap S falls and is placed on the scrap placement area 51. Thereafter, the scrap group SS after the scrap S has been dropped is photographed again by the transported scrap foreign object detection means 30, and the position of the foreign object D in the lifted scrap group SS is identified by the position identification unit 47. The process of dropping the scrap S onto the scrap placement location 51 is repeated until the distance d becomes equal to or less than a predetermined value, and when the distance d becomes equal to or less than the predetermined value, the conveying control unit 44 moves the position of the lifting magnet 21 as the conveying device 20 to above the foreign object placement location 52, and the foreign object separation control unit 48 weakens the holding force (magnetic force) of the lifting magnet 21 as the conveying device 20 to drop the foreign object D onto the foreign object placement location 52, thereby separating the foreign object D from the scrap S.

[0031] Then, after the foreign object D has been dropped onto the foreign object placement area 52, for the scrap S remaining in the lifted scrap group SS, the transport control unit 44 determines that the scrap S can be dropped and controls the position of the lifting magnet 21 of the transport device 20 to move above the scrap placement area 51, and the foreign object separation control unit 48 determines that the scrap S can be dropped and weakens the holding force (magnetic force) of the lifting magnet 21 of the transport device 20 to a holding force (magnetic force) that allows the scrap S to be dropped. As a result, the scrap S is dropped and placed on the scrap placement area 51.

[0032] A host computer (not shown) is connected to the transfer control unit 44. Information on the stopping position of the semi-trailer 50, the position information of the scrap placement location 51, and the position information of the foreign object placement location 52 are input from the host computer to the transfer control unit 44. The transfer control unit 44 controls the horizontal movement (transfer control) of the lifted scrap group SS based on the information on the stopping position of the semi-trailer 50, the position information of the scrap placement location 51, and the position information of the foreign object placement location 52 input from the host computer.

[0033] 4, the hardware configuration of the control device 40 will be described. The control device 40 is composed of an arithmetic processing device 401 equipped with a CPU 402. Connected to the CPU 402 via an internal bus 403 are an internal storage device 404 such as RAM and ROM, an external storage device 405, an input device 406 such as a keyboard and a mouse, and an output device 407 that outputs commands from the transport control unit 44 and the foreign object separation control unit 48 to the lifting magnet 21 serving as the transport device 20.

[0034] The external storage device 405 of the control device 40 includes a disk drive capable of reading data from a hard disk drive, solid state drive, or the like, and a drive device for CD, DVD, BD, or the like that reads data from the recording medium 408. The recording medium 408 that stores a program for causing the control device 40 to execute the following functions is set in this external storage device 405, and the read program is installed in the disk drive. The aforementioned functions include a preliminary image acquisition function by the preliminary image acquisition unit 41 (step S2, described below), a preliminary scrap foreign object detection function by the preliminary scrap foreign object detection unit 42 (step S3, described below), a foreign object location identification function by the preliminary position identification unit 43 (step S4, described below), a scrap group lifting control function by the conveyance control unit 44 (steps S5 and S11, described below), a photographed image acquisition function by the photographed image acquisition unit 45 (steps S7 and S13, described below), a foreign object detection function by the conveyed scrap foreign object detection unit 46 (steps S8 and S14, described below), a foreign object location identification function by the position identification unit 47 (step S9, described below), a foreign object separation control function by the foreign object separation control unit 48 and the conveyance control unit 44 controlling the conveyance device 20 (step S10, described below), and a scrap conveyance control function by the conveyance control unit 44 (step S15, described below). The program may be installed not only using the recording medium 408 but also by downloading the program via a network.

[0035] In accordance with the instructions of the installed program, the CPU 402 of the control device 40 executes the following functions: a preliminary image acquisition function by the preliminary image acquisition unit 41 (step S2 described below); a preliminary scrap foreign object detection function by the preliminary scrap foreign object detection unit 42 (step S3 described below); a foreign object position identification function by the preliminary position identification unit 43 (step S4 described below); a scrap group lifting control function by the conveyance control unit 44 (steps S5 and S11 described below); a photographed image acquisition function by the photographed image acquisition unit 45 (steps S7 and S13 described below); a foreign object detection function by the conveyed scrap foreign object detection unit 46 (steps S8 and S14 described below); a foreign object position identification function by the position identification unit 47 (step S9 described below); a foreign object separation control function by the foreign object separation control unit 48 and the conveyance control unit 44 controlling the conveyance device 20 (step S10 described below); and a scrap conveyance control function by the conveyance control unit 44 (step S15 described below), and outputs commands from the conveyance control unit 44 and the foreign object separation control unit 48 to the lifting magnet 21 serving as the conveyance device 20.

[0036] Next, the processing flow in the foreign matter separation system 1 will be described with reference to FIG. 3. FIG. 3 is a flowchart for explaining the processing flow in the foreign matter separation system shown in FIG. 1. First, in step S1, the pre-photography device 10 photographs the scrap group SS placed on the bed of the semi-trailer 50 from above the bed. That is, the pre-photography device 10 photographs the scrap group SS in advance before a portion of the scrap group SS is lifted by the lifting magnet 21 serving as the conveying device 20 (pre-photography step). Next, in step S2, the pre-image acquisition unit 41 of the control device 40 acquires the pre-photographed image G (see FIG. 5) captured by the pre-photography device 10 (pre-photographed image acquisition step).

[0037] Next, in step S3, the pre-scrap foreign matter detection unit 42 of the control device 40 detects foreign matter D in the scrap group SS before lifting from the pre-captured image G acquired in step S2 (pre-scrap foreign matter detection step). If foreign matter D is detected in step S3 (if the determination result is YES), the process proceeds to step S4, and if foreign matter D is not detected (if the determination result is NO), the process proceeds to step S11. In step S4, since foreign matter D has been detected in the scrap group SS before lifting, the pre-position identification unit 43 of the control device 40 identifies the position (position coordinates) of foreign matter D in the scrap group SS before lifting from the pre-captured image G acquired in step S2 (pre-position identification step).

[0038] Next, in step S5, the conveyance control unit 44 of the control device 40 controls the lifting magnet 21 serving as the conveyance device 20 to lift a portion of the scrap group SS containing the foreign object D, based on the position of the foreign object D in the scrap group SS before lifting identified in step S4 (lifting step). At this time, the conveyance control unit 44 first moves the lifting magnet 21 horizontally so that the lifting magnet 21 is positioned above the position of the foreign object D in the scrap group SS before lifting identified in step S4. Next, the conveyance control unit 44 controls the lifting magnet 21 to move vertically downward to hold a portion of the scrap group SS containing the foreign object D, and then to move the lifting magnet 21 vertically upward to lift the held portion of the scrap group SS.

[0039] Next, in step S6, the photographing device 31 of the transported scrap foreign matter detection means 30 photographs the scrap group SS lifted in step S5 (photographing step). Next, in step S7, the photographed image acquisition unit 45 of the transported scrap foreign matter detection means 30 acquires the photographed image taken in step S6 (photographed image acquisition step). Next, in step S8, the transported scrap foreign matter detection unit 46 of the transported scrap foreign matter detection means 30 detects foreign matter D in the lifted scrap group SS from the photographed image acquired in step S7 (transported scrap foreign matter detection step).

[0040] If a foreign object D is detected in step S8 (if the determination result is YES), the process proceeds to step S9, and if a foreign object D is not detected (if the determination result is NO), the process proceeds to step S15. Note that with regard to the detection of foreign object D in step S8 (transported scrap foreign object detection step), the pre-scrap foreign object detection unit 42 has already detected foreign object D in the scrap group SS before it was lifted from the pre-captured image G in step S3, so the determination result is usually YES.

[0041] If no foreign object D is detected in the scrap group SS before lifting in step S3 (the determination result is NO) and the process proceeds to step S11, the process proceeds to normal operation, and the conveyance control unit 44 of the control device 40 controls the lifting magnet 21 of the conveyance device 20 to lift a portion of the scrap group SS (lifting step). In this lifting step, the conveyance control unit 44 first moves the lifting magnet 21 horizontally so that the lifting magnet 21 is positioned above a specific position of the scrap group SS before lifting on the bed of the semi-trailer 50, based on stopping position information of the semi-trailer 50 input from a host computer (not shown). Next, the conveyance control unit 44 controls the lifting magnet 21 to move vertically downward to hold a portion of the scrap group SS, and then to move vertically upward to lift the held portion of the scrap group SS.

[0042] Then, in step S12, the photographing device 31 of the transported scrap foreign matter detection means 30 photographs the scrap group SS lifted in step S11 (photographing step). Next, in step S13, the photographed image acquisition unit 45 of the transported scrap foreign matter detection means 30 acquires the photographed image photographed in step S12 (photographed image acquisition step).

[0043] Next, in step S14, the transported scrap foreign matter detection unit 46 of the transported scrap foreign matter detection means 30 detects foreign matter D in the lifted scrap group SS from the photographed image acquired in step S13 (transported scrap foreign matter detection step). If foreign matter D is detected in step S14 (if the determination result is YES), the process proceeds to step S9, and if foreign matter D is not detected (if the determination result is NO), the process proceeds to step S15. In step S9, foreign matter D has been detected in the lifted scrap group SS, so the position identification unit 47 of the control device 40 identifies the position of foreign matter D in the lifted scrap group SS from the photographed image acquired in step S7 or step S13 (position identification step).

[0044] Next, in step S10, the foreign object separation control unit 48 and the transport control unit 44 of the control device 40 control the lifting magnet 21 as the transport device 20 to drop the scrap S and the foreign object D in the lifted scrap group SS to different locations based on the position of the foreign object D in the lifted scrap group SS identified in step S9, thereby separating the foreign object D included in the scrap group SS from the scrap S (separation step). Specifically, the foreign object separation control unit 48 of the control device 40 controls the lifting magnet 21 as the transport device 20 to adjust the holding force (magnetic force) that maintains the lifted state of the scrap group SS based on the position of the foreign object D in the lifted scrap group SS identified in step S9. Furthermore, the transport control unit 44 of the control device 40 controls the horizontal transport of the lifted scrap group SS by the lifting magnet 21 as the transport device 20 based on the position of the foreign object D in the lifted scrap group SS identified in step S9.

[0045] The specific method for separating the foreign object D is as described above. The position of the foreign object D in the scrap group SS is determined based on whether the distance d between the boundary line L between the scrap group SS and the background in the captured image and the foreign object D is equal to or less than a predetermined value, as shown in FIG. 6 . If the distance d is equal to or less than the predetermined value, the transport control unit 44 determines that the foreign object D can be dropped and controls the lifting magnet 21 of the transport device 20 to move above the foreign object placement area 52. Furthermore, the foreign object separation control unit 48 determines that the foreign object D can be dropped and weakens the holding force (magnetic force) of the lifting magnet of the transport device 20 to a holding force (magnetic force) that allows the foreign object D to be dropped. As a result, the foreign object D falls and is placed on the foreign object placement area 52. On the other hand, if the distance d is greater than the predetermined value, the transport control unit 44 determines that the scrap S can be dropped and controls the lifting magnet 21 of the transport device 20 to move above the scrap placement area 51. Furthermore, the foreign matter separation control unit 48 determines that the scrap S can be dropped and weakens the holding force (magnetic force) of the lifting magnet of the conveying device 20 to a holding force (magnetic force) that allows the scrap S to be dropped. As a result, the scrap S drops and is placed on the scrap placement area 51. The scrap group SS after the scrap S has been dropped is then photographed again by the conveyed scrap foreign matter detection means 30, and the position of the foreign matter D in the lifted scrap group SS is identified by the position identification unit 47. The process of dropping the scrap S onto the scrap placement area 51 is repeated until the distance d becomes equal to or less than a predetermined value. When the distance d becomes equal to or less than the predetermined value, the conveying control unit 44 moves the position of the lifting magnet 21 of the conveying device 20 above the foreign matter placement area 52, and the foreign matter separation control unit 48 weakens the holding force (magnetic force) of the lifting magnet 21 of the conveying device 20 to drop the foreign matter D onto the foreign matter placement area 52, thereby separating the foreign matter D from the scrap S.

[0046] Then, after the foreign object D has been dropped onto the foreign object placement area 52, the transport control unit 44 determines that the scrap S remaining in the lifted scrap group SS can be dropped, and controls the position of the lifting magnet serving as the transport device 20 to move above the scrap placement area 51, while the foreign object separation control unit 48 determines that the scrap S can be dropped, and weakens the holding force (magnetic force) of the lifting magnet serving as the transport device 20 to a holding force (magnetic force) that allows the scrap S to be dropped. As a result, the scrap S is dropped and placed on the scrap placement area 51.

[0047] In step S15, since foreign matter D is not included in the lifted scrap group SS, the system transitions to normal operation, and the transport control unit 44 of the control device 40 controls the position of the lifting magnet 21 serving as the transport device 20 to move above the scrap placement location 51. The foreign matter separation control unit 48 also weakens the holding force (magnetic force) of the lifting magnet 21 serving as the transport device 20 to a holding force (magnetic force) that allows the scrap S to fall, causing the scrap group SS to fall and be placed on the scrap placement location 51. This completes the processing in the foreign matter separation system 1.

[0048] As described above, the foreign matter separation system 1 according to the first embodiment includes a lifting magnet 21 as a conveying device 20 that lifts and conveys a portion of the scrap group SS, and a conveyed scrap foreign matter detection means 30 that detects foreign matter D in the scrap group SS lifted by the lifting magnet 21. The foreign matter separation system 1 also includes a control device 40 that, when the conveyed scrap foreign matter detection means 30 detects foreign matter D in the lifted scrap group SS, identifies the position of the foreign matter D in the lifted scrap group SS and controls the lifting magnet 21 to drop the scrap S and the foreign matter D in the lifted scrap group SS to different locations based on the identified position of the foreign matter D in the lifted scrap group SS, thereby separating the foreign matter D contained in the scrap group SS from the scrap S. This makes it possible to automatically remove only the foreign matter D contained in the scrap group SS, thereby reducing the amount of scrap S that is removed together with the foreign matter D from the scrap group SS. In other words, the amount of scrap S that is removed together with the foreign matter D can be reduced compared to when the foreign matter D is simply lifted up from the scrap group SS and removed.

[0049] Furthermore, according to the foreign matter separation system 1 of the first embodiment, the transported scrap foreign matter detection means 30 includes a photographing device 31 that photographs the scrap group SS lifted by the lifting magnet 21 serving as the transport device 20, an image acquisition unit 45 that acquires the image photographed by the photographing device 31, and a transported scrap foreign matter detection unit 46 that detects foreign matter D in the lifted scrap group SS from the image acquired by the image acquisition unit 45. This makes it possible to detect foreign matter D in the lifted scrap group SS by photographing the scrap group SS lifted by the lifting magnet 21 with the photographing device 31.

[0050] Furthermore, according to the foreign matter separation system 1 of the first embodiment, the control device 40 includes a position identification unit 47 that identifies the position of the foreign matter D in the lifted scrap group SS from the captured image when the transported scrap foreign matter detection means 30 detects the foreign matter D in the lifted scrap group SS. The control device 40 also includes a foreign matter separation control unit 48 that controls the lifting magnet 21 serving as a transport device to adjust the holding force that maintains the lifted state of the scrap group SS based on the position of the foreign matter D in the lifted scrap group SS identified by the position identification unit 47, and a transport control unit 44 that controls the transport of the lifted scrap group SS by the lifting magnet 21. The foreign matter separation control unit 48 adjusts the holding force that maintains the lifted state of the scrap group SS by the lifting magnet 21, and the transport control unit 44 controls the transport of the lifted scrap group SS, thereby separating the foreign matter D contained in the scrap group SS from the scrap S. As a result, based on the position of the foreign matter D in the lifted scrap group SS, the foreign matter separation control unit 48 adjusts the holding force that maintains the lifted state of the scrap group SS by the lifting magnet 21 as the conveying device 20, and by controlling the conveyance of the lifted scrap group SS by the conveyance control unit 44, only the foreign matter D contained in the scrap group SS can be automatically and accurately removed.

[0051] The foreign matter separation system according to the first embodiment further includes a pre-photography device 10 that photographs the scrap group SS in advance before a portion of the scrap group SS is lifted by the lifting magnet 21 serving as the conveying device 20. The control device 40 includes a pre-photography image acquisition unit 41 that acquires a pre-photography image G captured by the pre-photography device 10, and a pre-scrap foreign matter detection unit 42 that detects a foreign matter D in the scrap group SS before lifting from the pre-photography image G acquired by the pre-image acquisition unit 41. The control device 40 also includes a pre-position identification unit 43 that, when a foreign matter D is detected in the scrap group SS before lifting by the pre-scrap foreign matter detection unit 42, identifies the position of the foreign matter D in the scrap group SS before lifting from the pre-photography image G, and a conveyance control unit 44 that controls the lifting magnet 21 serving as the conveying device 20 to lift a portion of the scrap group SS including the foreign matter D, based on the position of the foreign matter D in the scrap group SS before lifting identified by the pre-position identification unit 43. This makes it possible to detect foreign objects D in the scrap group SS before lifting and identify their positions using the images captured by the pre-photography device 10, and based on the position of the foreign objects D, the lifting magnet 21 serving as the conveying device 20 can lift a portion of the scrap group SS containing the foreign objects D.

[0052] Furthermore, the foreign matter separation method according to the first embodiment includes a lifting step (steps S5 and S11) in which the control device 40 controls the lifting magnet 21 serving as the conveying device 20 to lift a portion of the scrap group SS, a transported scrap foreign matter detection step (steps S6 to S8, steps S12 to S14) in which the transported scrap foreign matter detection means 30 detects foreign matter D in the scrap group SS lifted in the lifting step, and a position identification step (step S9) in which the control device 40 identifies the position of the foreign matter D in the lifted scrap group SS if foreign matter D is detected in the lifted scrap group SS in the transported scrap foreign matter detection step. The foreign object separation method also includes a separation step (step S10) in which the control device 40 controls the lifting magnet 21 serving as the conveying device 20 to drop the scrap S and the foreign objects D in the lifted scrap group SS at different locations based on the position of the foreign objects D in the lifted scrap group SS identified in the position identification step, thereby separating the foreign objects D contained in the scrap group SS from the scrap S. This makes it possible to automatically remove only the foreign objects D contained in the scrap group SS, thereby reducing the amount of scrap S removed together with the foreign objects D in the scrap group SS. In other words, compared to simply lifting the foreign objects D in the scrap group SS to remove them, it is possible to reduce the amount of scrap S removed together with the foreign objects D.

[0053] In addition, according to the program of the first embodiment, the program causes the control device 40 to execute a lifting step (steps S5, S11) of controlling the lifting magnet 21 as the conveying device 20 to lift a portion of the scrap group SS, a position identification step (step S9) of identifying the position of the foreign object D in the lifted scrap group SS when the conveyed scrap foreign object detection means 30 detects the foreign object D in the scrap group SS lifted in the lifting step, and a separation step (step S10) of controlling the lifting magnet 21 as the conveying device 20 to drop the scrap S and the foreign object D in the lifted scrap group SS to different locations based on the position of the foreign object D in the lifted scrap group SS identified in the position identification step, thereby separating the foreign object D contained in the scrap group SS from the scrap S. As a result, the control device 40 executes the lifting step (steps S5 and S11), the position specifying step (step S9), and the separation step (step S10) in accordance with the instructions of the program, and can automatically remove only the foreign matter D contained in the scrap group SS, thereby reducing the amount of scrap S that is removed together with the foreign matter D from the scrap group SS.

[0054] Furthermore, according to the computer-readable recording medium 408 having stored thereon a program relating to the first embodiment, the computer-readable recording medium 408 has stored therein a program for causing the control device 40 to execute the following steps: a lifting step (steps S5, S11) of controlling the lifting magnet 21 as the conveying device 20 to lift a portion of the scrap group SS; a position identification step (step S9) of identifying the position of the foreign object D in the lifted scrap group SS when the conveyed scrap foreign object detection means 30 detects the foreign object D in the scrap group SS lifted in the lifting step; and a separation step (step S10) of controlling the lifting magnet 21 as the conveying device 20 to drop the scrap S and the foreign object D in the lifted scrap group SS to different locations based on the position of the foreign object D in the lifted scrap group SS identified in the position identification step, thereby separating the foreign object D contained in the scrap group SS from the scrap S. As a result, the control device 40 executes the lifting step (steps S5 and S11), the position specifying step (step S9), and the separation step (step S10) in accordance with the commands of the program stored in the recording medium 408, and can automatically remove only the foreign matter D contained in the scrap group SS, thereby reducing the amount of scrap S that is removed together with the foreign matter D from the scrap group SS.

[0055] Second Embodiment Next, a foreign matter separation system, a foreign matter separation method, a program, and a computer-readable recording medium storing the program according to a second embodiment of the present invention will be described with reference to FIGS. 9 and 10 . FIG. 9 is a functional block diagram of the foreign matter separation system according to the second embodiment of the present invention. FIG. 10 is a flowchart for explaining the processing flow in the foreign matter separation system shown in FIG. 9 . The foreign matter separation system 1 according to the second embodiment of the present invention shown in FIG. 9 separates foreign matter D contained in a scrap group SS from scrap S, similar to the foreign matter separation system 1 according to the first embodiment shown in FIG. 1 .

[0056] The foreign matter separation system 1 according to the second embodiment differs from the foreign matter separation system 1 according to the first embodiment shown in FIG. 1 in that it does not include the pre-photography device 10 and instead includes a conveying device 20, a conveyed scrap foreign matter detection means 30, and a control device 40. In the foreign matter separation system 1 according to the first embodiment, the pre-photography device 10 photographs the scrap group SS placed on the loading platform of a semi-trailer 50 (see FIG. 1) before the scrap group SS is lifted by a lifting magnet 21 serving as the conveying device 20. Then, a pre-image acquisition unit 41 acquires a pre-photographed image G (see FIG. 5) captured by the pre-photography device 10, and a pre-scrap foreign matter detection unit 42 detects foreign matter D in the scrap group SS before it is lifted from the pre-photographed image G acquired by the pre-image acquisition unit 41. When a foreign object D is detected in the scrap group SS before lifting by the pre-scrap foreign object detection unit 42, the pre-position identification unit 43 identifies the position (position coordinates) of the foreign object D in the scrap group SS before lifting from the pre-captured image G.

[0057] In contrast, in the foreign matter separation system 1 according to the second embodiment, the pre-photography device 10, pre-image acquisition unit 41, pre-scrap foreign matter detection unit 42, and pre-position identification unit 43 are omitted, and pre-photography is not performed before the lifting magnet 21 serving as the conveying device 20 lifts the scrap group SS. In the foreign matter separation system 1 according to the second embodiment, the conveyance control unit 44 of the control device 40 controls the horizontal movement of the lifting magnet 21 serving as the conveying device 20 based on stopping position information of the semi-trailer 50 input from a host computer (not shown), and positions the lifting magnet 21 above the loading platform of the stopped semi-trailer 50. The conveyance control unit 44 then controls the lifting magnet 21 to lift a portion of the scrap group SS.

[0058] The conveying device 20 in the foreign matter separation system 1 according to the second embodiment, like the conveying device 20 in the foreign matter separation system 1 according to the first embodiment, lifts and conveys a portion of the scrap mass SS placed on the bed of a semi-trailer 50 (see FIG. 1 ), and is a lifting magnet 21 that lifts and conveys a portion of the scrap mass SS by magnetic force. The lifting magnet 21 as the conveying device 20 is movable vertically and horizontally, similar to that shown in FIG. 1 . The lifting magnet 21 moves vertically downward to hold a portion of the scrap mass SS, moves vertically upward to lift the held portion of the scrap mass SS, and moves horizontally to convey the lifted portion of the scrap mass SS.

[0059] Like the conveyed scrap foreign matter detection means 30 of the foreign matter separation system 1 according to the first embodiment, the conveyed scrap foreign matter detection means 30 detects foreign matter D in the scrap group SS lifted by the lifting magnet 21 serving as the conveying device 20, and includes a photographing device 31 that photographs the scrap group SS lifted by the lifting magnet 21, an image acquisition unit 45 (described later) of the control device 40 that acquires the images photographed by the photographing device 31, and a conveyed scrap foreign matter detection unit 46 (described later) of the control device 40 that detects foreign matter D in the lifted scrap group SS from the images acquired by the image acquisition unit 45. Like the photographing device 31 of the foreign matter separation system 1 according to the first embodiment, the photographing device 31 is a camera that photographs the scrap group SS lifted by the lifting magnet 21 serving as the conveying device 20.

[0060] The photographed image acquisition unit 45 is a component of the control device 40 and acquires the photographed images taken by the photographing device 31. The transported scrap foreign matter detection unit 46 is a component of the control device 40 and detects foreign matter D in the lifted scrap group SS from the photographed images acquired by the photographed image acquisition unit 45. Any method may be used for detecting foreign matter D from the photographed images by the transported scrap foreign matter detection unit 46, but in the second embodiment, the transported scrap foreign matter detection unit 46 uses a learning model that has been trained with photographed images of the scrap group SS containing foreign matter D, and inputs the photographed images acquired by the photographed image acquisition unit 45 into the learning model to detect foreign matter D in the scrap group SS. In other words, the transported scrap foreign matter detection unit 46 determines whether or not foreign matter D is present in the scrap group SS.

[0061] The control device 40 has a function of controlling the lifting magnet 21 serving as the conveying device 20 to lift a portion of the scrap group SS. The control device 40 also has a function of identifying the position of the foreign object D in the lifted scrap group SS when the conveyed scrap foreign object detection means 30 detects the foreign object D in the lifted scrap group SS. The control device 40 also has a function of controlling the lifting magnet 21 serving as the conveying device 20 to drop the scrap S and the foreign object D in the lifted scrap group SS to different locations based on the identified position of the foreign object D in the lifted scrap group SS, thereby separating the foreign object D contained in the scrap group SS from the scrap S.

[0062] First, the control device 40 includes a conveyance control unit 44 for controlling the lifting magnet 21 serving as the conveying device 20 to lift a portion of the scrap group SS. As described above, the conveyance control unit 44 controls the lifting magnet 21 serving as the conveying device 20 to lift a portion of the scrap group SS containing foreign objects D, based on the stopping position information of the semi-trailer 50 input from a host computer (not shown). At this time, the conveyance control unit 44, as described above, moves the lifting magnet 21 horizontally so that the lifting magnet 21 is positioned above the bed of the semi-trailer 50, based on the stopping position information of the semi-trailer 50 input from a host computer (not shown). Next, the conveyance control unit 44 controls the lifting magnet 21 to move vertically downward to hold a portion of the scrap group SS containing foreign objects D, and then to move the lifting magnet 21 vertically upward to lift the held portion of the scrap group SS.

[0063] The control device 40 also includes a position identification unit 47, a foreign object separation control unit 48, and the aforementioned conveyance control unit 44 to achieve the functions of identifying the position of the foreign object D in the lifted scrap group SS and separating the foreign object D contained in the scrap group SS from the scrap S. When the conveyed scrap foreign object detection means 30 (the photographing device 31, the photographed image acquisition unit 45, and the conveyed scrap foreign object detection unit 46) detects a foreign object D in the lifted scrap group SS, the position identification unit 47 identifies the position of the foreign object D in the lifted scrap group SS from the photographed image acquired by the photographed image acquisition unit 45. The foreign object separation control unit 48 also controls the conveyance device 20 to adjust the holding force that maintains the lifted state of the scrap group SS, based on the position of the foreign object D in the lifted scrap group SS identified by the position identification unit 47.

[0064] Furthermore, the transport control unit 44 controls the horizontal transport of the lifted scrap group SS by the lifting magnet 21 serving as the transport device 20, based on the position of the foreign matter D in the lifted scrap group SS identified by the position identification unit 47. The control device 40 then controls the foreign matter separation control unit 48 to adjust the holding force that maintains the lifted state of the scrap group SS by the transport device 20, and controls the transport of the lifted scrap group SS by the transport control unit 44, thereby separating the foreign matter D contained in the scrap group SS from the scrap S.

[0065] To explain this foreign object separation control in more detail, as in the first embodiment, the position of the foreign object D in the scrap group SS is determined based on whether the distance d between the boundary line L between the scrap group SS and the background in the captured image and the foreign object D is equal to or less than a predetermined value, as shown in FIG. 6 . If the distance d is equal to or less than the predetermined value, the transport control unit 44 determines that the foreign object D can be dropped and controls the position of the lifting magnet of the transport device 20 to move above the foreign object placement area 52, and the foreign object separation control unit 48 determines that the foreign object D can be dropped and weakens the holding force (magnetic force) of the lifting magnet of the transport device 20 to a holding force (magnetic force) that allows the foreign object D to be dropped. As a result, the foreign object D falls and is placed on the foreign object placement area 52. On the other hand, if the distance d is greater than the predetermined value, the conveyance control unit 44 determines that the scrap S can be dropped and controls the position of the lifting magnet of the conveyance device 20 to move above the scrap placement location 51, and the foreign matter separation control unit 48 determines that the scrap S can be dropped and weakens the holding force (magnetic force) of the lifting magnet of the conveyance device 20 to a holding force (magnetic force) that allows the scrap S to be dropped. As a result, the scrap S is dropped and placed on the scrap placement location 51. Thereafter, the scrap group SS after the scrap S has been dropped is photographed again by the conveyed scrap foreign matter detection means 30, and the position of the foreign matter D in the lifted scrap group SS is identified by the position identification unit 47. The process of dropping the scrap S onto the scrap placement area 51 is repeated until the distance d becomes less than a predetermined value, and when the distance d becomes less than the predetermined value, the conveying control unit 44 moves the position of the lifting magnet 21 as the conveying device 20 to above the foreign object placement area 52, and the foreign object separation control unit 48 weakens the holding force (magnetic force) of the lifting magnet 21 as the conveying device 20 to drop the foreign object D onto the foreign object placement area 52, thereby separating the foreign object D from the scrap S.

[0066] Then, after the foreign object D has been dropped onto the foreign object placement area 52, the transport control unit 44 determines that the scrap S remaining in the lifted scrap group SS can be dropped, and controls the position of the lifting magnet serving as the transport device 20 to move above the scrap placement area 51, while the foreign object separation control unit 48 determines that the scrap S can be dropped, and weakens the holding force (magnetic force) of the lifting magnet serving as the transport device 20 to a holding force (magnetic force) that allows the scrap S to be dropped. As a result, the scrap S is dropped and placed on the scrap placement area 51.

[0067] 4, the hardware configuration of the control device 40 is similar to that of the first embodiment, and is configured by an arithmetic processing device 401 equipped with a CPU 402. Connected to the CPU 402 via an internal bus 403 are an internal storage device 404 such as RAM and ROM, an external storage device 405, an input device 406 such as a keyboard and a mouse, and an output device 407 that outputs commands from the transport control unit 44 and the foreign matter separation control unit 48 to the lifting magnet 21 serving as the transport device 20.

[0068] The external storage device 405 of the control device 40 includes a disk drive capable of reading data from a hard disk drive, solid state drive, or the like, and a drive device for CDs, DVDs, BDs, or the like that reads data from the recording medium 408. A recording medium 408 storing a program for causing the control device 40 to execute the following functions is inserted into the external storage device 405, and the read program is installed in the disk drive. The functions include a scrap group lifting control function by the transport control unit 44 (step S21, described below), an image acquisition function by the image acquisition unit 45 (step S23, described below), a foreign object detection function by the transported scrap foreign object detection unit 46 (step S24, described below), a foreign object position identification function by the position identification unit 47 (step S25, described below), a foreign object separation control function by the foreign object separation control unit 48 and the transport control unit 44 controlling the transport device 20 (step S26, described below), and a scrap transport control function by the transport control unit 44 (step S27, described below). The program installation is not limited to using the recording medium 408, but may also be performed by downloading the program via a network.

[0069] The CPU 402 of the control device 40, in accordance with the instructions of the installed program, executes a scrap group lifting control function by the conveying control unit 44 (step S21 described later), a photographic image acquisition function by the photographic image acquisition unit 45 (step S23 described later), a foreign object detection function by the conveyed scrap foreign object detection unit 46 (step S24 described later), a foreign object position identification function by the position identification unit 47 (step S25 described later), a foreign object separation control function by controlling the conveying device 20 by the foreign object separation control unit 48 and the conveying control unit 44 (step S26 described later), and a scrap conveying control function by the conveying control unit 44 (step S27 described later), and outputs instructions from the conveying control unit 44 and the foreign object separation control unit 48 to the lifting magnet 21 serving as the conveying device 20.

[0070] Next, the processing flow of the foreign object separation system 1 according to the second embodiment will be described with reference to FIG. 10 . First, in step S21, the conveyance control unit 44 of the control device 40 controls the lifting magnet 21 of the conveyance device 20 to lift a portion of the scrap mass SS containing the foreign object D based on the stopping position information of the semi-trailer 50 input from a host computer (not shown) (lifting step). At this time, the conveyance control unit 44 horizontally moves the lifting magnet 21 so that the lifting magnet 21 is positioned above the bed of the semi-trailer 50 based on the stopping position information of the semi-trailer 50 input from the host computer (not shown). Next, the conveyance control unit 44 controls the lifting magnet 21 to move vertically downward to hold a portion of the scrap mass SS containing the foreign object D, and then to move vertically upward to lift the held portion of the scrap mass SS.

[0071] Next, in step S22, the photographing device 31 of the transported scrap foreign matter detection means 30 photographs the scrap group SS lifted in step S21 (photographing step). Next, in step S23, the photographed image acquisition unit 45 of the transported scrap foreign matter detection means 30 acquires the photographed image taken in step S22 (photographed image acquisition step). Next, in step S24, the transported scrap foreign matter detection unit 46 of the transported scrap foreign matter detection means 30 detects foreign matter D in the lifted scrap group SS from the photographed image acquired in step S23 (transported scrap foreign matter detection step). If foreign matter D is detected in step S24 (if the determination result is YES), the process proceeds to step S25, and if foreign matter D is not detected (if the determination result is NO), the process proceeds to step S27. In step S25, since a foreign object D is detected in the lifted scrap group SS, the position identification unit 47 of the control device 40 identifies the position of the foreign object D in the lifted scrap group SS from the photographed image acquired in step S23 (position identification step).

[0072] Next, in step S26, the foreign object separation control unit 48 and the transport control unit 44 of the control device 40 control the lifting magnet 21 as the transport device 20 to drop the scrap S and the foreign object D in the lifted scrap group SS to different locations based on the position of the foreign object D in the lifted scrap group SS identified in step S25, thereby separating the foreign object D contained in the scrap group SS from the scrap S (separation step). Specifically, the foreign object separation control unit 48 of the control device 40 controls the lifting magnet 21 as the transport device 20 to adjust the holding force (magnetic force) that maintains the lifted state of the scrap group SS based on the position of the foreign object D in the lifted scrap group SS identified in step S25. Furthermore, the transport control unit 44 of the control device 40 controls the horizontal transport of the lifted scrap group SS by the lifting magnet 21 as the transport device 20 based on the position of the foreign object D in the lifted scrap group SS identified in step S9.

[0073] As in the first embodiment, the specific method for separating the foreign object D is to determine the position of the foreign object D in the scrap group SS based on whether the distance d between the boundary line L between the scrap group SS and the background in the captured image and the foreign object D is equal to or less than a predetermined value (see FIG. 6 ). If the distance d is equal to or less than the predetermined value, the transport control unit 44 determines that the foreign object D can be dropped and controls the lifting magnet 21 of the transport device 20 to move above the foreign object placement area 52. Furthermore, the foreign object separation control unit 48 determines that the foreign object D can be dropped and weakens the holding force (magnetic force) of the lifting magnet of the transport device 20 to a holding force (magnetic force) that allows the foreign object D to be dropped. As a result, the foreign object D falls and is placed on the foreign object placement area 52. On the other hand, if the distance d is greater than the predetermined value, the transport control unit 44 determines that the scrap S can be dropped and controls the lifting magnet 21 of the transport device 20 to move above the scrap placement area 51. Furthermore, the foreign matter separation control unit 48 determines that the scrap S can be dropped and weakens the holding force (magnetic force) of the lifting magnet of the conveying device 20 to a holding force (magnetic force) that allows the scrap S to be dropped. As a result, the scrap S drops and is placed on the scrap placement area 51. The scrap group SS after the scrap S has been dropped is then photographed again by the conveyed scrap foreign matter detection means 30, and the position of the foreign matter D in the lifted scrap group SS is identified by the position identification unit 47. The process of dropping the scrap S onto the scrap placement area 51 is repeated until the distance d becomes equal to or less than a predetermined value. When the distance d becomes equal to or less than the predetermined value, the conveying control unit 44 moves the position of the lifting magnet 21 of the conveying device 20 above the foreign matter placement area 52, and the foreign matter separation control unit 48 weakens the holding force (magnetic force) of the lifting magnet 21 of the conveying device 20 to drop the foreign matter D onto the foreign matter placement area 52, thereby separating the foreign matter D from the scrap S.

[0074] Then, after the foreign object D has been dropped onto the foreign object placement area 52, the transport control unit 44 determines that the scrap S remaining in the lifted scrap group SS can be dropped, and controls the position of the lifting magnet serving as the transport device 20 to move above the scrap placement area 51, while the foreign object separation control unit 48 determines that the scrap S can be dropped, and weakens the holding force (magnetic force) of the lifting magnet serving as the transport device 20 to a holding force (magnetic force) that allows the scrap S to be dropped. As a result, the scrap S is dropped and placed on the scrap placement area 51.

[0075] In step S27, since foreign matter D is not included in the lifted scrap group SS, the system transitions to normal operation, and the transport control unit 44 of the control device 40 controls the position of the lifting magnet 21 serving as the transport device 20 to move above the scrap placement location 51. The foreign matter separation control unit 48 also weakens the holding force (magnetic force) of the lifting magnet 21 serving as the transport device 20 to a holding force (magnetic force) that allows the scrap S to fall, causing the scrap group SS to fall and be placed on the scrap placement location 51. This completes the processing in the foreign matter separation system 1.

[0076] As described above, the foreign matter separation system 1 according to the second embodiment includes a lifting magnet 21 as a conveying device 20 that lifts and conveys a portion of the scrap group SS, and a conveyed scrap foreign matter detection means 30 that detects foreign matter D in the scrap group SS lifted by the lifting magnet 21. The foreign matter separation system 1 also includes a control device 40 that, when the conveyed scrap foreign matter detection means 30 detects foreign matter D in the lifted scrap group SS, identifies the position of the foreign matter D in the lifted scrap group SS, and controls the lifting magnet 21 to drop the scrap S and the foreign matter D in the lifted scrap group SS to different locations based on the identified position of the foreign matter D in the lifted scrap group SS, thereby separating the foreign matter D contained in the scrap group SS from the scrap S.

[0077] This allows only the foreign objects D contained in the scrap group SS to be automatically removed, thereby reducing the amount of scrap S removed together with the foreign objects D from the scrap group SS. In other words, compared to simply lifting the foreign objects D in the scrap group SS to remove them, the amount of scrap S removed together with the foreign objects D can be reduced. Furthermore, unlike the foreign object separation system 1 of the first embodiment, the foreign object separation system 1 of the second embodiment omits the pre-photography device 10, pre-image acquisition unit 41, pre-scrap foreign object detection unit 42, and pre-position identification unit 43, and does not perform pre-photography before lifting the scrap group SS with the lifting magnet 21 serving as the conveying device 20. This allows for simplification of the equipment and the foreign object separation process.

[0078] Furthermore, according to the foreign matter separation system 1 of the second embodiment, the transported scrap foreign matter detection means 30 includes a photographing device 31 that photographs the scrap group SS lifted by the lifting magnet 21 serving as the transport device 20, an image acquisition unit 45 that acquires the image photographed by the photographing device 31, and a transported scrap foreign matter detection unit 46 that detects foreign matter D in the lifted scrap group SS from the image acquired by the image acquisition unit 45. This makes it possible to detect foreign matter D in the lifted scrap group SS by photographing the scrap group SS lifted by the lifting magnet 21 with the photographing device 31.

[0079] Furthermore, in the foreign matter separation system 1 according to the second embodiment, the control device 40 includes a position identification unit 47 that identifies the position of the foreign matter D in the lifted scrap group SS from the captured image when the transported scrap foreign matter detection means 30 detects the foreign matter D in the lifted scrap group SS. The control device 40 also includes a foreign matter separation control unit 48 that controls the lifting magnet 21 serving as a transport device to adjust the holding force that maintains the lifted state of the scrap group SS based on the position of the foreign matter D in the lifted scrap group SS identified by the position identification unit 47, and a transport control unit 44 that controls the transport of the lifted scrap group SS by the lifting magnet 21. The foreign matter separation control unit 48 adjusts the holding force that maintains the lifted state of the scrap group SS by the lifting magnet 21, and the transport control unit 44 controls the transport of the lifted scrap group SS, thereby separating the foreign matter D contained in the scrap group SS from the scrap S. As a result, based on the position of the foreign matter D in the lifted scrap group SS, the foreign matter separation control unit 48 adjusts the holding force that maintains the lifted state of the scrap group SS by the lifting magnet 21 as the conveying device 20, and by controlling the conveyance of the lifted scrap group SS by the conveyance control unit 44, only the foreign matter D contained in the scrap group SS can be automatically and accurately removed.

[0080] The foreign matter separation method according to the second embodiment includes a lifting step (step S21) in which the control device 40 controls the lifting magnet 21 serving as the conveying device 20 to lift a portion of the scrap group SS, a conveyed scrap foreign matter detection step (steps S22 to S24) in which the conveyed scrap foreign matter detection means 30 detects foreign matter D in the scrap group SS lifted in the lifting step, and a position identification step (step S25) in which the control device 40 identifies the position of the foreign matter D in the lifted scrap group SS if the foreign matter D is detected in the lifted scrap group SS in the conveyed scrap foreign matter detection step. The foreign matter separation method also includes a separation step (step S26) in which the control device 40 controls the lifting magnet 21 serving as the conveying device 20 to drop the scrap S and the foreign matter D in the lifted scrap group SS at different locations based on the position of the foreign matter D in the lifted scrap group SS identified in the position identification step, thereby separating the foreign matter D contained in the scrap group SS from the scrap S. This makes it possible to automatically remove only the foreign objects D contained in the scrap group SS, thereby reducing the amount of scrap S that is removed from the scrap group SS together with the foreign objects D. In other words, compared to the case where the foreign objects D are simply lifted up from the scrap group SS and removed, it is possible to reduce the amount of scrap S that is removed together with the foreign objects D.

[0081] In addition, the program according to the second embodiment causes the control device 40 to execute a lifting step (step S21) of controlling the lifting magnet 21 as the conveying device 20 to lift a portion of the scrap group SS, a position identification step (step S25) of identifying the position of the foreign object D in the lifted scrap group SS when the conveyed scrap foreign object detection means 30 detects the foreign object D in the scrap group SS lifted in the lifting step, and a separation step (step S26) of controlling the lifting magnet 21 as the conveying device 20 to drop the scrap S and the foreign object D in the lifted scrap group SS to different locations based on the position of the foreign object D in the lifted scrap group SS identified in the position identification step, thereby separating the foreign object D contained in the scrap group SS from the scrap S. As a result, the control device 40 executes the lifting step (step S21), the position identification step (step S25) and the separation step (step S26) in accordance with the instructions of the program, and can automatically remove only the foreign matter D contained in the scrap group SS, thereby reducing the amount of scrap S that is removed together with the foreign matter D from the scrap group SS.

[0082] Furthermore, according to the computer-readable recording medium 408 having stored thereon a program relating to the second embodiment, the computer-readable recording medium 408 has stored therein a program for causing the control device 40 to execute the following steps: a lifting step (step S21) of controlling the lifting magnet 21 as the conveying device 20 to lift a portion of the scrap group SS; a position identification step (step S25) of identifying the position of the foreign object D in the lifted scrap group SS when the conveyed scrap foreign object detection means 30 detects the foreign object D in the scrap group SS lifted in the lifting step; and a separation step (step S26) of controlling the lifting magnet 21 as the conveying device 20 to drop the scrap S and the foreign object D in the lifted scrap group SS to different locations based on the position of the foreign object D in the lifted scrap group SS identified in the position identification step, thereby separating the foreign object D contained in the scrap group SS from the scrap S.

[0083] As a result, the control device 40 executes the lifting step (step S21), the position specifying step (step S25), and the separation step (step S26) in accordance with the commands of the program stored in the recording medium 408, and can automatically remove only the foreign matter D contained in the scrap group SS, thereby reducing the amount of scrap S that is removed together with the foreign matter D from the scrap group SS. While the present invention has been described above as an embodiment, the present invention is not limited to this and various modifications and improvements can be made.

[0084] For example, although the foreign object separation system 1 according to the first and second embodiments uses a lifting magnet 21 as the conveying device 20, the present invention is not limited to the use of the lifting magnet 21. For example, as shown in FIG. 7 , a grapple 22 may be used as the conveying device 20, or as shown in FIG. 8 , a shovel 23 may be used as the conveying device. When the grapple 22 is used as the conveying device 20, the "holding force of the conveying device 20" can be adjusted by widening the opening width of the claws 22a of the grapple 22, as shown in FIG. 7 . Furthermore, when the shovel 23 is used as the conveying device, the "holding force of the conveying device 20" can be adjusted by changing the inclination of the bucket 23a of the shovel 23, as shown in FIG. 8 .

[0085] Furthermore, in the foreign matter separation system 1 according to the first embodiment, the transport control unit 44 of the control device 40 controls the lifting magnet 21 serving as the transport device 20 to lift a portion of the scrap group SS containing the foreign matter D, based on the position of the foreign matter D in the scrap group SS before lifting, as identified by the preliminary position identification unit 43. That is, as in the example shown in FIG. 5 , the transport control unit 44 controls the lifting magnet 21 to lift a portion of the scrap group SS containing the foreign matter D located at the lifting position X. Then, in a subsequent operation, the foreign matter D contained in the lifted scrap group SS is separated from the scrap S.

[0086] In contrast, as in a foreign matter separation system according to a modified example (not shown), the transport control unit of the control device controls the transport device to lift a portion of the scrap group SS that does not contain the foreign matter D based on the position of the foreign matter D in the scrap group SS before lifting, as determined by the preliminary position determination unit. The transport control unit may then control the transport device to transport the lifted portion of the scrap group SS that does not contain the foreign matter D to its destination. FIG. 11 shows an example of a pre-photographed image of the scrap group SS placed on a semi-trailer 50 (see FIG. 1 ) captured by a pre-photographing device when the foreign matter D contained in the scrap group SS is separated from the scrap S using the foreign matter separation system according to the modified example, along with the lifting position Y of the scrap group SS by the transport device. That is, as shown in FIG. 11 , the transport control unit of the foreign matter separation system control device according to the modified example first moves the transport device horizontally so that the transport device is positioned above a position that avoids the position of the foreign matter D in the scrap group SS before lifting, as determined by the preliminary position determination unit. Next, the conveyance control unit controls the conveyance device to move vertically downward to hold a portion of the scrap group SS that does not contain foreign matter D (the scrap group SS at lifting position Y), and then to move the conveyance device vertically upward to lift the held portion of the scrap group SS. The conveyance control unit may then control the conveyance device to transport the lifted portion of the scrap group SS that does not contain foreign matter D to the destination. By repeating this process, the scrap S can be transported to the destination while leaving the foreign matter D on the bed of the semi-trailer 50.

[0087] Furthermore, in the foreign matter separation system according to the modified example, when the scrap S cannot be lifted due to the obstruction of the foreign matter D, the foreign matter D may be appropriately moved aside, and the scrap S may be lifted and transported, as shown in FIG. 12 . That is, in FIG. 12 , when the scrap S cannot be lifted due to the obstruction of the foreign matter D, a portion V1 of the scrap group SS containing the foreign matter D is moved aside, and the remaining collection W1 of scrap S is lifted and transported. Furthermore, for the portion V1 of the scrap group SS containing the removed foreign matter D, a portion V2 of the scrap group SS containing the portion V1 of the scrap group SS containing the removed foreign matter D is moved aside, and the remaining collection W2 of scrap S is lifted and transported. This process may be repeated. FIG. 12 shows an example of controlling the transport device to separate the foreign matter D contained in the scrap group SS from the scrap when the scrap S cannot be lifted due to the obstruction of the foreign matter D using the foreign matter separation system according to the modified example. In Figure 12, for example, when removing a portion V2 of the scrap group SS containing foreign matter D, as in the first and second embodiments, the portion V2 of the scrap group SS containing the lifted foreign matter D is photographed, the position of the foreign matter D is identified from the photographed image, and the conveying device is controlled to remove the scrap S in the portion V2 of the scrap group SS and the foreign matter D to different locations based on the position of the foreign matter D, thereby separating the foreign matter D from the scrap S.

[0088] Furthermore, in the foreign matter separation system 1 according to the first and second embodiments, the determination of the position of the foreign matter D in the lifted scrap mass SS is not limited to whether the distance d between the boundary line L between the scrap mass SS and the background in the captured image and the foreign matter D is equal to or less than a predetermined value. For example, the determination of the position of the foreign matter D in the lifted scrap mass SS may be made based on whether the position (height in the vertical direction) of the foreign matter in the scrap mass SS in the captured image exceeds a certain threshold. Furthermore, the location where the scrap mass SS is placed is not limited to the loading platform of the semi-trailer 50, but may also be a yard or the like.

[0089] REFERENCE SIGNS LIST 1 Foreign object separation system 10 Pre-photographing device 20 Conveying device 21 Lifting magnet 22 Grapple 22a Claw 23 Shovel 23a Bucket 30 Conveyed scrap foreign object detection means 31 Photography device 40 Control device 41 Pre-image acquisition unit 42 Pre-scrap foreign object detection unit 43 Pre-position identification unit 44 Conveying control unit 45 Photographic image acquisition unit 46 Conveyed scrap foreign object detection unit 47 Position identification unit 48 Foreign object separation control unit 401 Arithmetic processing unit 402 CPU 403 Internal bus 404 Internal storage device 405 External storage device 406 Input device 407 Output device 408 Recording medium D Foreign object G Pre-photographed image S Scrap SS Scrap group

Claims

1. A foreign matter separation system for separating foreign matter contained in a scrap load from the scrap, comprising: a conveying device for lifting up and conveying a portion of the scrap load; a conveyed scrap foreign matter detection means for detecting foreign matter in the scrap load lifted by the conveying device; and a control device for, when a foreign matter in the lifted scrap load is detected by the conveyed scrap foreign matter detection means, identifying a position of the foreign matter in the lifted scrap load and controlling the conveying device to drop the scrap and the foreign matter in the lifted scrap load to different locations based on the identified position of the foreign matter in the lifted scrap load, thereby separating the foreign matter contained in the scrap load from the scrap.

2. The foreign matter separation system of claim 1, wherein the transported scrap foreign matter detection means comprises a photographing device that photographs the group of scrap lifted by the transporting device, an image acquisition unit that acquires the image captured by the photographing device, and a transported scrap foreign matter detection unit that detects foreign matter in the group of scrap lifted from the image acquired by the image acquisition unit.

3. The control device is equipped with a position identification unit that, when a foreign object in the lifted scrap group is detected by the transported scrap foreign object detection means, identifies the position of the foreign object in the lifted scrap group from the captured image, and a foreign object separation control unit that controls the conveying device to adjust the holding force that maintains the lifted state of the scrap group based on the position of the foreign object in the lifted scrap group identified by the position identification unit, and a conveying control unit that controls the conveying of the lifted scrap group by the conveying device, characterized in that the foreign object separation control unit adjusts the holding force that maintains the lifted state of the scrap group by the conveying device and the conveying control unit controls the conveying of the lifted scrap group, thereby separating foreign objects contained in the scrap group from the scrap.

4. The foreign matter separation system of claim 3, further comprising a pre-photography device that photographs the scrap group in advance before a portion of the scrap group is lifted by the conveying device, and the control device comprises a pre-image acquisition unit that acquires the pre-photographed image taken by the pre-photography device, a pre-scrap foreign matter detection unit that detects a foreign matter in the scrap group before lifting from the pre-photographed image acquired by the pre-image acquisition unit, a pre-position identification unit that, when a foreign matter is detected in the scrap group before lifting by the pre-scrap foreign matter detection unit, identifies the position of the foreign matter in the scrap group before lifting from the pre-photographed image, and the conveying control unit that controls the conveying device to lift a portion of the scrap group containing the foreign matter based on the position of the foreign matter in the scrap group before lifting identified by the pre-position identification unit.

5. A foreign matter separation method for separating foreign matter contained in a group of scrap from the scrap, comprising: a lifting step in which a control device controls a conveying device to lift a portion of the group of scrap; a conveyed scrap foreign matter detection step in which a conveyed scrap foreign matter detection means detects a foreign matter in the group of scrap lifted in the lifting step; a position identification step in which the control device identifies a position of the foreign matter in the lifted group of scrap if a foreign matter is detected in the conveyed scrap foreign matter detection step; and a separation step in which the control device controls the conveying device to drop the scrap and the foreign matter in the lifted group of scrap to different locations based on the position of the foreign matter in the lifted group of scrap identified in the position identification step, thereby separating the foreign matter contained in the group of scrap from the scrap.

6. A program for causing a control device to execute the following steps: a lifting step of controlling a conveying device to lift a portion of the scrap group; a position identification step of identifying a position of a foreign object in the lifted scrap group when a foreign object in the scrap group lifted in the lifting step is detected by a conveyed scrap foreign object detection means; and a separation step of controlling the conveying device to drop the scrap and the foreign object in the lifted scrap group to different locations based on the position of the foreign object in the lifted scrap group identified in the position identification step, thereby separating the foreign object contained in the scrap group from the scrap.

7. A computer-readable recording medium having stored thereon a program for causing a control device to execute the following steps: a lifting step of controlling a conveying device to lift a portion of the scrap group; a position identification step of identifying a position of a foreign object in the lifted scrap group when a foreign object in the lifted scrap group is detected in the lifting step by a conveyed scrap foreign object detection means; and a separation step of controlling the conveying device to drop the scrap and the foreign object in the lifted scrap group to different locations based on the position of the foreign object in the lifted scrap group identified in the position identification step, thereby separating the foreign object contained in the scrap group from the scrap.

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