Rope shape detection device, crane, rope shape detection method, and program

Abstract

To provide a rope shape detection apparatus, a crane, a rope shape detection method, and a program which can accurately detect the shape of a wound wire rope wound.SOLUTION: A rope shape detection apparatus 1 comprises: an image acquisition part 21 which acquires an image from an imaging apparatus 10 which captures an image of a hook provided in a crane, and a wire rope wound between the hook and a boom head; a segmentation part 22 which extracts a rope region including the hook in the image and an image part of the wire rope on the basis of light and shade and color distribution of the image acquired by the image acquisition part 21; a trajectory calculation part 23 which obtains a vertical direction in the image on the basis of positional information of the imaging apparatus 10, and obtains a trajectory of a first mass point in the image when it is assumed that the first mass point moves along the rope region extracted by the segmentation part 22 or in the obtained vertical direction or on the opposite side to the vertical direction; and a shape specifying part 24 which specifies the shape of the wire rope from the trajectory obtained by the trajectory calculation part 23.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a rope shape detection device, a crane, a rope shape detection method, and a program. [Background technology]

[0002] Cranes are sometimes provided with a sway angle detection device that measures the sway of the wire rope in order to prevent load sway.

[0003] For example, Patent Document 1 discloses a sway angle detection device that includes an imaging device that images the side of a wire rope hanging from a crane, and a control unit that determines the inclination of the wire rope from the image captured by the imaging device.

[0004] In the sway angle detection device described in Patent Document 1, the control unit binarizes the image of the imaging device to extract the wire region. The control unit also obtains the angle at which the strip-shaped upper pixel region and lower pixel region intersect with the wire region, and outputs the angle as the inclination of the wire rope. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2006-337253 A Summary of the Invention [Problem to be solved by the invention]

[0006] Incidentally, in a crane, a wire rope is sometimes wound between the boom head sheave and the hook sheave.

[0007] In the case of the sway angle detection device described in Patent Document 1, the imaging device is installed on the side of the wire rope, so when the wire rope is wound in this manner, the wire rope is captured as an image of multiple wire ropes extending in the vertical direction.

[0008] However, the sway angle detection device described in Patent Document 1 only binarizes the image captured by the imaging device and extracts the wire area. Therefore, the sway angle detection device cannot separate the areas in the image where each wire rope is captured. As a result, it is difficult to accurately detect the inclination of the wire rope.

[0009] In addition, in a crane, it is desirable to detect the number of wound wire ropes in order to obtain the tension of the wire rope and the load of the winch. In other words, it is desirable to detect the shape of the wound wire rope.

[0010] However, the sway angle detection device described in Patent Document 1 only detects the inclination of one wire rope, and therefore cannot detect the exact shape of the wound wire rope.

[0011] The present invention has been made to solve the above-mentioned problems, and aims to provide a rope shape detection device, a crane, a rope shape detection method, and a program that can accurately detect the shape of a wound wire rope. [Means for solving the problem]

[0012] In order to achieve the above object, a rope shape detection device according to a first aspect of the present invention comprises: an image acquisition unit that acquires images from an imaging device that captures an image of a hook provided on the crane and a wire rope that is wound between the hook and the boom head; A segmentation unit that extracts a rope region including an image portion of the hook and the wire rope in the image based on the shading and color distribution of the image acquired by the image acquisition unit; A vertical direction in the image is obtained based on position information of the imaging device, and along the rope region extracted by the segmentation unit, The inside of the rope area, a trajectory calculation unit that calculates a trajectory of the first mass point in the image when it is assumed that the first mass point moves in the calculated vertical direction or in a direction opposite to the calculated vertical direction; a shape specifying unit that specifies a shape of the wire rope from the trajectory calculated by the trajectory calculation unit; Equipped with.

[0013] The trajectory calculation unit is a directly below position calculation unit that calculates a position directly below the boom head in an image captured by the imaging device based on imaging position information of the imaging device; a line-shaped area calculation unit that calculates a line-shaped area that is assumed to cross the upper end of the imaged wire rope in the image captured by the imaging device based on the imaging position information; A starting point setting unit that sets the center of a crossing portion as a starting point each time the line-shaped area calculated by the line-shaped area calculation unit crosses the upper end portion of the rope area extracted by the segmentation unit; The direction from the origin set by the origin setting unit to the position directly below calculated by the directly below position calculation unit is defined as the vertical direction, and the first mass point moves along the rope region in the vertical direction. Move to A calculation unit that calculates a trajectory of the first mass point in an image when the first mass point is assumed to move; may have the following structure:

[0014] The trajectory calculation unit may also calculate the trajectory of the first mass point when it is assumed that the first mass point is sandwiched between two second mass points from a direction perpendicular to the vertical direction, the first mass point moves in the vertical direction or in the direction opposite to the vertical direction, and when one of the two second mass points leaves the rope region, a repulsive force is applied to the first mass point toward the other of the two second mass points.

[0015] The shape identification unit may determine the vertical length of the rope region from the trajectory, and if the determined length is greater than a threshold value, determine the shape of the wire rope from the trajectory.

[0016] A crane according to a second aspect of the present invention comprises: An imaging device provided on the boom head for imaging a wire rope suspended from a sheave of the boom head; A rope shape detection device according to a first aspect of the present invention; Equipped with.

[0017] A rope shape detection method according to a third aspect of the present invention comprises: an image acquiring step of acquiring an image from an imaging device that captures an image of a hook provided on the crane and a wire rope that is wound between the hook and the boom head; A segmentation step of extracting a rope region including an image portion of the hook and the wire rope in the image based on the shading and color distribution of the image acquired in the image acquisition step; A vertical direction in the image is obtained based on position information of the imaging device, and along the rope region extracted in the segmentation step, The inside of the rope area, a trajectory calculation step of calculating a trajectory of the first mass point in the image when it is assumed that the first mass point moves in the calculated vertical direction or in a direction opposite to the calculated vertical direction; a shape identification step of identifying a shape of the wire rope from the trajectory obtained in the trajectory calculation step; Equipped with.

[0018] A program according to a fourth aspect of the present invention comprises: 11 is a program for causing a computer to execute a rope shape detection method according to a third aspect of the present invention. Effect of the Invention

[0019] According to the configuration of the present invention, the trajectory calculation unit determines the vertical direction in the image based on the position information of the imaging device, and determines the trajectory of the first mass point in the image assuming that the first mass point moves in the determined vertical direction along the rope area extracted by the segmentation unit, and the shape identification unit identifies the shape of the wire rope from the trajectory. Therefore, it is possible to extract only the wire rope extending vertically from the boom head and identify its shape. According to the configuration of the present invention, the shape of the wire rope can be accurately detected. [Brief description of the drawings]

[0020] [Figure 1] 1 is a side view of a rough terrain crane equipped with a rope shape detection device according to an embodiment of the present invention. [Diagram 2] FIG. 2 is a block diagram showing a configuration of a rope shape detection device. [Diagram 3] FIG. 2 is a hardware configuration diagram of a control unit provided in the rope shape detection device. [Figure 4] 1 is a diagram showing an example of an image captured by an imaging device provided in the rope shape detection device. FIG. [Diagram 5] 1 is a diagram showing an example of a rope region extracted by a segmentation unit included in the rope shape detection device; [Figure 6] 4 is a block diagram showing a configuration of a trajectory calculation unit included in the rope shape detection device. FIG. [Figure 7] 11 is a conceptual diagram showing the positional relationship between a line-shaped area and a starting point calculated by a trajectory calculation unit. FIG. [Figure 8] 1 is an enlarged view of a rope region showing the positional relationship between seeds and whiskers used by a calculation unit provided in a trajectory calculation unit of the rope shape detection device. FIG. [Figure 9] A close-up of the rope region showing the position of the seed and the direction of the repulsive force when the whisker leaves the rope region. [Figure 10] 13 is a conceptual diagram of a trajectory of a seed calculated by a calculation unit. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0021] Hereinafter, a rope shape detection device, a crane, a rope shape detection method, and a program according to embodiments of the present invention will be described in detail with reference to the drawings. In the drawings, the same or equivalent parts are denoted by the same reference numerals.

[0022] The rope shape detection device according to the embodiment is a device that is installed on a rough terrain crane. This rope shape detection device detects the shape of a wire rope wound between a sheave of a boom head and a hook sheave. First, the configuration of the rough terrain crane and the winding of the wire rope will be described with reference to Fig. 1.

[0023] FIG. 1 is a side view of a rough terrain crane 100 equipped with a rope shape detection device 1 according to an embodiment of the present invention.

[0024] As shown in Figure 1, the rough terrain crane 100 comprises a boom 120 mounted on a rotating body 110 on a vehicle body 101 having a traveling function, and a hook 140 for hoisting a load, which is connected to a wire rope 130 hanging down from the tip of the boom 120.

[0025] The boom 120 has a foot pin at its base attached to a bracket, and its middle part is supported by a hoisting cylinder. This allows the boom 120 to be raised and lowered. The boom 120 is also of a telescopic type and can be extended and retracted. A boom head 121 is provided at the tip of the boom 120. A tip sheave 150 is provided inside the boom head 121, and a wire rope 130 is hung on the tip sheave 150.

[0026] The wire rope 130 is connected to a winch drum 160 provided near the base of the boom 120. The wire rope 130 extends from the winch drum 160 toward the tip sheave 150 described above. The wire rope 130 is wound around the tip sheave 150 and then hangs down below it. A hook 140 is connected to the wire rope 130.

[0027] The hook 140 is provided with a hook sheave 170. The above-mentioned hanging wire rope 130 is hung on the hook sheave 170. The hook 140 rises or falls as the winch drum 160 rotates and the wire rope 130 is wound up or down.

[0028] As described above, the tip sheave 150 is provided on the boom head 121, and the hook sheave 170 is provided on the hook 140. The wire rope 130 is wound around the hook sheave 170 and the tip sheave 150 to reduce tension.

[0029] 1, a plurality of hook sheaves 170 are provided on the hook 140. A plurality of tip sheaves 150 are also provided on the boom head 121. To adjust the tension, the wire rope 130 is wound around these hook sheaves 170 and tip sheaves 150 a desired number of times. Hereinafter, this number of times will be referred to as the number of windings.

[0030] Meanwhile, the rough terrain crane 100 is equipped with an overload prevention device 200 that calculates the load to prevent tipping and damage. This overload prevention device 200 calculates the weight of the load using the number of lines of wire. For this reason, to operate the overload prevention device 200 accurately, the operator needs to accurately grasp the number of lines of wire and input this number accurately.

[0031] However, as described above, the wire rope 130 is wound around the hook sheave 170 and the tip sheave 150 by any number of turns. Also, as described above, the wire rope 130 is wound up and down by the winch drum 160, and its length changes. As a result, the shape of the wound wire rope 130 can become complex, making it difficult to grasp the exact number of turns.

[0032] Therefore, in order to enable the operator to know the accurate number of wound parts, the rough terrain crane 100 is equipped with a rope shape detection device 1. Next, the configuration of the rope shape detection device 1 will be described with reference to Figs. 2 to 5.

[0033] FIG. 2 is a block diagram showing the configuration of the rope shape detection device 1. FIG. 3 is a hardware configuration diagram of the control unit 20 included in the rope shape detection device 1. FIG. 4 is a diagram showing an example of an image captured by the imaging device 10 included in the rope shape detection device 1. FIG. 5 is a diagram showing an example of a rope region 220 extracted by the segmentation unit 22 included in the rope shape detection device 1. In FIG. 4, the imaging device 10 captures an image of the wire rope 130 when the number of windings is 4. FIG. 5 also shows the rope region 220 extracted by the segmentation unit 22 from the image captured of the wire rope 130 shown in FIG. 4.

[0034] As shown in FIG. 2, the rope shape detection device 1 includes an imaging device 10, a control unit 20 which performs various processes such as image processing and detection of the number of wound ropes, a memory unit 30 which stores data, programs, etc. used in the processes of the control unit 20, and a display device 40 which displays the results of the various processes.

[0035] The imaging device 10 uses a suspended load monitoring camera that monitors a load suspended from a hook 140.

[0036] In detail, the imaging device 10 is installed on the boom head 121 as shown in FIG. 1. In order to monitor the suspended load, a lens (not shown) is directed downward. As a result, the imaging device 10 captures an image of the suspended load viewed from above as shown in FIG. 4. As a result, the imaging device 10 captures an image of the wire rope 130 extending downward from the boom head 121 and the hook 140 suspended by the wire rope 130. Note that in FIG. 4, the imaging device 10 also captures an image of the over-hoisting prevention device 180. The imaging device 10 transmits image data created by capturing the image to the control unit 20.

[0037] On the other hand, the control unit 20 includes a computer having a CPU (Central Processing Unit) 50 and a memory 60, and an I / O port 70 for connecting the imaging device 10 and the display device 40, as shown in FIG.

[0038] The control unit 20 is realized by the CPU 50 executing the rope shape detection program 31 stored in the storage unit 30. The control unit 20 has processing blocks configured as software. In detail, the control unit 20 has each of the processing blocks of an image acquisition unit 21, a segmentation unit 22, a trajectory calculation unit 23, and a shape identification unit 24 shown in FIG.

[0039] The image acquisition unit 21 acquires image data generated by the imaging device 10. For example, when the imaging device 10 generates 30 frames of image data per second, the image acquisition unit 21 acquires image data corresponding to one of the frames. The image acquisition unit 21 then transmits the acquired image data to the segmentation unit 22. Note that, depending on the processing capabilities of the segmentation unit 22, the trajectory calculation unit 23, etc., the image acquisition unit 21 may acquire image data every time the imaging device 10 generates the image data.

[0040] The segmentation unit 22 performs pre-processing on the image data received from the image acquisition unit 21. That is, the segmentation unit 22 extracts an area (hereinafter, referred to as a rope area) in which the hook 140 and the wire rope 130 are imaged from the received image data. For example, the segmentation unit 22 extracts the rope area 220 shown in FIG. 5 by binarizing the image data.

[0041] More specifically, the storage unit 30 shown in FIG. 2 stores extraction parameters 32 necessary for extracting the rope region 220. The extraction parameters 32 include threshold data for binarization processing determined in advance by experiments, for example. The segmentation unit 22 reads out the extraction parameters 32 stored in the storage unit 30, and extracts the rope region 220 from the image data based on the read out extraction parameters 32 and the shading data of the image data. The segmentation unit 22 then transmits in-image position data of the extracted rope region 220 to the trajectory calculation unit 23 together with the image data. The segmentation unit 22 may extract the rope region 220 based on color distribution or shading gradient, in addition to extracting the rope region 220 by binarization processing.

[0042] The trajectory calculation unit 23 calculates the trajectory of a mass point called a seed, assuming that the mass point falls in the direction of gravity (also called the gravity direction) along the rope region 220 extracted by the segmentation unit 22.

[0043] In detail, the rope area 220 extracted by the segmentation unit 22 includes image portions of components other than the wire rope 130, such as the hook 140 and the overwinding prevention device 180 shown in FIG. 4. On the other hand, unlike other components, the wire rope 130 tends to have a shape that extends straight in the vertical direction as a result of hanging down from the boom head 121. Therefore, the trajectory calculation unit 23 uses the properties of the wire rope 130 to extract the shape of the wire rope 130 from the rope area 220 extracted by the segmentation unit 22. That is, the trajectory calculation unit 23 assumes that the mass point, that is, the seed, falls from above to below along the rope area 220, and calculates the trajectory of the seed at that time. As a result, the trajectory calculation unit 23 extracts the shape of only the wire rope 130. The trajectory calculation unit 23 has various processing blocks to perform such processing. Next, the processing blocks of the trajectory calculation unit 23 will be described.

[0044] Fig. 6 is a block diagram showing the configuration of the trajectory calculation unit 23. Fig. 7 is a conceptual diagram showing the positional relationship between the line-shaped region A and the starting point P1 calculated by the trajectory calculation unit 23. Note that in Fig. 7, since the line-shaped region A has a small width, only the length direction is shown by a dotted line.

[0045] As shown in FIG. 6, the trajectory calculation unit 23 includes a directly below position calculation unit 231 which calculates the directly below position in the image to determine the falling direction of the seed, i.e., the direction of gravity, a line-shaped area calculation unit 232 which calculates a line-shaped area crossing the upper end side of the image portion of the wire rope 130 to be used for setting the starting point when the seed falls, a starting point setting unit 233 which sets the above-mentioned starting point using the line-shaped area, and a calculation unit 234 which calculates the trajectory of the seed when it falls along the rope area 220 from the set starting point.

[0046] The directly below position calculation unit 231 calculates the coordinates in the image of the directly below position which is the movement direction of the seed.

[0047] In detail, the directly below position calculation unit 231 reads out the imaging position data 34 from the storage unit 30. The imaging position data 34 stores data such as the orientation of the lens of the imaging device 10 and the position of the imaging device 10 relative to the tip sheave 150 of the boom head 121. For example, the imaging position data 34 stores position data such as that the lens of the imaging device 10 faces directly below, i.e., in the vertical direction, and that the imaging device 10 is located at a position a predetermined distance away from the center of the tip sheave 150 in the directly below direction. The directly below position calculation unit 231 reads out this imaging position data 34 and calculates the directly below coordinate P0 in FIG. 7 that is directly below the boom head 121 in the image based on the read imaging position data 34. That is, it calculates the directly below coordinate P0 in the image where the wire rope 130 will hang down and extend. The directly below position calculation unit 231 transmits the calculated directly below coordinate P0 to the calculation unit 234 shown in FIG. 6.

[0048] When the imaging device 10 is set in advance so that the center of the image is directly below the boom head 121, the directly below position calculation unit 231 may set the directly below coordinate P0 as the coordinate of the center of the image without reading out the imaging position data 34 from the storage unit 30. In addition, the imaging position data 34 is also referred to as imaging position information in this specification.

[0049] On the other hand, in order to set the starting point of the seed, the line-shaped area calculation unit 232 calculates a line-shaped area A shown in Fig. 7 which is assumed to cross the upper end side of the image portion of the wire rope 130 in the captured image. In detail, the above-mentioned imaging position data 34 shown in Fig. 6 stores data on the line position and width of the line-shaped area A relative to the orientation and position of the lens of the imaging device 10, which are obtained in advance by experiment. The line-shaped area calculation unit 232 reads out the imaging position data 34 from the storage unit 30, and calculates the line-shaped area A shown in Fig. 7 from the read imaging position data 34.

[0050] For example, the imaging position data 34 shown in FIG. 6 stores position data of the imaging device 10 indicating that the imaging device 10 is disposed on the left side of the boom head 121, and position data indicating that a line of a constant width parallel to the right side of the image is provided at a predetermined position in the right region of the image captured by the imaging device 10. In this case, the line-shaped area calculation unit 232 draws a line of a constant width parallel to the right side of the image at a predetermined position in the right region of the image based on the imaging position data 34, and sets it as a line-shaped area A. At this time, it is preferable that the imaging position data 34 stores position data of multiple lines in order to obtain a line-shaped area A that more reliably crosses the upper end side of the image portion of the wire rope 130. Then, the line-shaped area calculation unit 232 may calculate multiple line-shaped areas A shown in FIG. 7. The line-shaped area calculation unit 232 transmits the obtained position of the line-shaped area A to the starting point setting unit 233.

[0051] Returning to FIG. 6, the starting point setting unit 233 sets a starting point in the extracted rope region 220.

[0052] In detail, the starting point setting unit 233 sets a starting point from the rope region 220 extracted by the segmentation unit 22 and the line-shaped region A calculated by the line-shaped region calculation unit 232 described above.

[0053] Explaining this with reference to Fig. 7, in the example shown in Fig. 7, the imaging device 10 captures an image of the wire rope 130 having four windings from the left side of the boom head 121. Therefore, the rope region 220 extracted by the segmentation unit 22 has four radial parts extending radially from the center of the image toward the periphery of the right region of the image.

[0054] On the other hand, the line-shaped region A calculated by the line-shaped region calculation unit 232 is parallel to the right side of the image, and therefore crosses each of the radial portions of the rope region 220.

[0055] The starting point setting unit 233 identifies an overlapping portion between the rope region 220 and the linear region A, and sets the center of the overlapping portion as the starting point P1. More specifically, a crossing portion where the linear region A crosses the above-mentioned radial portion of the rope region 220 is obtained, and the starting point P1 is set at the center of the crossing portion. The starting point setting unit 233 transmits the in-image position data of the set starting point P1 to the calculation unit 234 shown in FIG. 6.

[0056] The calculation unit 234 calculates the trajectory of the seed when it falls in the gravity direction G along the rope region 220 from the starting point P1 shown in FIG.

[0057] In detail, the calculation unit 234 first obtains the gravity direction G at each starting point P1 in order to determine the falling direction of the seeds. That is, the calculation unit 234 obtains the direction from each starting point P1 toward the directly below coordinate P0 calculated by the directly below position calculation unit 231, and sets the direction as the gravity direction G. Note that, for ease of understanding, the gravity direction G is shown only for some of the starting points P1 in FIG. 7, but the calculation unit 234 obtains the gravity direction G for all of the starting points P1.

[0058] Next, the calculation unit 234 sets the calculated unit length of the gravity direction G as a unit vector. The calculation unit 234 sets the unit vector as the motion vector of the seed, and calculates the displacement of the seed with respect to the motion vector.

[0059] At this time, in order to move the seed along the rope region 220, the calculation unit 234 assumes that the seed is sandwiched between two whiskers, which are mass points other than the seed, and moves while receiving a repulsive force from those whiskers 242. It is also assumed that the seed moves along the rope region 220 due to the repulsive force.

[0060] Fig. 8 is an enlarged view of the rope region 220 showing the positional relationship between the seed 241 and the whisker 242 used by the calculation unit 234 provided in the trajectory calculation unit 23. Fig. 9 is an enlarged view of the rope region 220 showing the position of the seed 241 and the direction of the repulsive force F when the whisker 242 deviates from the rope region 220.

[0061] 8, the calculation unit 234 assumes that the seed 241 moves together with the whiskers 242, sandwiched between the whiskers 242 spaced apart by a certain distance in a direction D perpendicular to the gravity direction G. Then, the calculation unit 234 assumes that when the whiskers 242 move out of the rope region 220 due to the movement of the seed 241, the seed 241 receives a repulsive force F from the whiskers 242 that have moved out of the rope region 220, as shown in FIG.

[0062] Here, the repulsive force F is a force applied to the seed 241 to move the seed 241 away from the outside of the rope region 220. Its direction is from the whisker 242 that has gone outside the rope region 220 toward the other whisker 242. The magnitude of the repulsive force F may increase as the whisker 242 moves away from the rope region 220, or may be constant regardless of the distance of the whisker 242 from the rope region 220.

[0063] The calculation unit 234 calculates the displacement of the seed 241 by assuming that the seed 241 moves based on the vector of this repulsive force F and the above-mentioned motion vector. The calculation unit 234 calculates the trajectory of the seed 241 by calculating the time series of the displacement of the seed 241, that is, the transition of the coordinates of the seed 241.

[0064] This calculation of the trajectory is performed until the seed 241 can no longer move in the gravity direction G within the rope region 220, that is, until it reaches the end of the rope region 220 in the gravity direction G. In addition, the calculation is performed for each of the starting points P1 set by the starting point setting unit 233.

[0065] FIG. 10 is a conceptual diagram of the trajectory of the seed 241 determined by the calculation unit 234. As shown in FIG.

[0066] 10, when the wire rope 130 extends in the direction of gravity G, the calculation unit 234 obtains a trajectory of the shape of a line L along the wire rope 130 based on the motion vector of the direction of gravity G and the vector of the repulsive force of the whisker 242 acting on the seed 241. The trajectory is along the central axis of the wire rope 130, i.e., the core rope of the wire rope 130.

[0067] Returning to FIG. 2, the trajectory calculation unit 23 transmits coordinate group data representing the determined trajectory, that is, trajectory data, to the shape specification unit 24.

[0068] The shape specification unit 24 receives the trajectory data from the trajectory calculation unit 23, and determines the length of the trajectory from the trajectory data. The shape specification unit 24 also reads out the threshold data 33 stored in the storage unit 30, and determines that the trajectory calculation unit 23 has normally detected the trajectory when the determined trajectory length is greater than the read out threshold.

[0069] When the shape specifying unit 24 determines that the detection is normal, it regards the trajectory data as shape data representing the shape of the central axis of the wire rope 130. In other words, it regards the data as data representing the shape of the core rope of the wire rope 130 (hereinafter, simply referred to as shape data of the wire rope 130).

[0070] On the other hand, if the shape identification unit 24 determines that the detection has not been normal, it assumes that the trajectory data is not shape data of the wire rope 130, but data representing the shape of a part other than the wire rope 130, for example, data representing the shape of the overwinding prevention device 180 or the wire rope attached to the overwinding prevention device 180.

[0071] The shape specifying unit 24 counts the number of wound parts from the trajectory data, which is the shape data of the wire rope 130, and transmits the counted number of wound parts to the overload prevention device 200. In addition, the shape specifying unit 24 transmits the trajectory data, which is the shape data of the wire rope 130, to the display device 40.

[0072] The display device 40 is configured with a liquid crystal display or an organic electroluminescence display. The display device 40 receives image data from the imaging device 10 and displays the image captured by the imaging device 10. The display device 40 also displays the trajectory data received from the shape specifying unit 24. The display device 40 displays an image of the wire rope 130 to the operator of the rough terrain crane 100, and also displays the basic shape of the wire rope as a trajectory, making it easier for the operator to recognize the number of wire ropes wound.

[0073] In addition, the shape identification unit 24 transmits the counted number of wrapped pieces to the overload prevention device 200, but it may also transmit the data of the counted number of wrapped pieces to the display device 40 and display the number of wrapped pieces on the display device 40.

[0074] In this specification and claims, the above-mentioned gravity direction G is also referred to as the vertical direction. The seeds 241 and the whiskers 242 are also referred to as the first mass point and the second mass point. Furthermore, the steps performed by each of the processing blocks of the image acquisition unit 21, the segmentation unit 22, the trajectory calculation unit 23, and the shape specification unit 24 are also referred to as an image acquisition step, a segmentation step, a trajectory calculation step, and a shape specification step.

[0075] As described above, in the rope shape detection device 1 according to the embodiment, the trajectory calculation unit 23 obtains the gravity direction G in the image based on the position information of the imaging device 10, and obtains the trajectory of the seed 241 in the image assuming that the seed 241 moves in the obtained gravity direction G along the rope region 220 extracted by the segmentation unit 22. In addition, the shape identification unit 24 identifies the shape of the wire rope 130 from the trajectory of the seed 241. Therefore, it is possible to extract only the wire rope 130 extending from the boom head 121 in the gravity direction G and identify its shape. As a result, it is possible to accurately detect the shape of the wire rope 130.

[0076] Since the rope shape detection device 1 can accurately detect the shape of the wire rope 130, it can accurately identify the shape of the wire rope 130 when the wire rope 130 is wound around the tip sheave 150 of the boom head 121 and the hook sheave 170 of the hook 140.

[0077] In the rope shape detection device 1, the start point setting unit 233 included in the trajectory calculation unit 23 sets multiple start points P1, and the calculation unit 234 calculates the trajectory of the seed 241 from each of the start points P1, so even if the operator changes the number of windings, the change can be easily accommodated and the shape of the wire rope 130 can be detected. As a result, the rope shape detection device 1 can detect the accurate number of windings.

[0078] The trajectory calculated by the trajectory calculation unit 23 is the central axis of the wire rope 130, that is, the shape of the core rope of the wire rope 130. This allows the rope shape detection device 1 to accurately detect the shape of the wire rope 130.

[0079] Although the embodiment of the present invention has been described above, the present invention is not limited to the above embodiment. For example, in the above embodiment, the segmentation unit 22 extracts the rope region 220 by binarization processing, but the present invention is not limited to this. In the present invention, the segmentation unit 22 may extract the rope region 220 based on the gradient of the shading of the image.

[0080] In detail, the segmentation unit 22 may calculate the edge of the shading of the image, and detect the contour line from the calculated edge of the shading to extract the rope region 220. In this case, the trajectory calculation unit 23 may specify the transverse direction of the rope region 220 from the gradient of the shading of the image, and arrange the seeds 241 and the whiskers 242 in the transverse direction.

[0081] In the above embodiment, the trajectory calculation unit 23 calculates the trajectory until the seed 241 reaches the end of the rope region 220 in the gravity direction G. That is, the trajectory calculation unit 23 sets the end of the seed 241 in the gravity direction G of the rope region 220 as the end point. However, the present invention is not limited to this. In the present invention, after the seed 241 reaches the end point, the trajectory from the end point to the starting point P1 may be calculated again. Then, a more accurate trajectory may be calculated by comparing the trajectory from the starting point P1 to the end point. For example, if there is a local bend in the trajectory from the starting point P1 to the end point and there is no such bend in the trajectory from the end point to the starting point P1, the wire rope 130 may be considered to be linear, and the trajectory from the end point to the starting point P1 may be adopted.

[0082] In addition, in the image captured by the imaging device 10, all of the wire ropes 130 extend from the periphery of the image toward the hook 140 in the center of the image, so in order to obtain a more accurate number of windings of the wire rope 130, it is better to find the trajectory from the starting point P1 to the end point.

[0083] In the above embodiment, a suspended load monitoring camera is used as the imaging device 10, but the present invention is not limited to this. In the present invention, the imaging device 10 may be a dedicated camera for imaging the shape of the wire rope 130.

[0084] In the above embodiment, the rope shape detection device 1 is equipped with the imaging device 10, but the rope shape detection device 1 does not have to be equipped with the imaging device 10 as long as it can acquire images from the imaging device 10. For example, the rope shape detection device 1 may be a device separate from the load monitoring camera.

[0085] In the above embodiment, the rope shape detection device 1 is connected to the overload prevention device 200, but in the present invention, the connection to the overload prevention device 200 is optional. Therefore, the rope shape detection device 1 may not be connected to the overload prevention device 200 and may simply display the detected shape of the wire rope 130 on the display device 40. Even in this form, it is possible to prompt the operator to check the number of wound wire ropes.

[0086] In embodiments 1 and 2, the rope shape detection device 1 is equipped on a rough terrain crane 100, but the present invention is applicable to all cranes in which the wire rope 130 is wound around a plurality of hook sheaves 170 provided on the hook 140 and a plurality of tip sheaves 150 provided at the tip of the boom 120. [Explanation of symbols]

[0087] 1...rope shape detection device, 10...imaging device, 20...control unit, 21...image acquisition unit, 22...segmentation unit, 23...trajectory calculation unit, 24...shape identification unit, 30...storage unit, 31...rope shape detection program, 32...extraction parameters, 33...threshold data, 34...imaging position data, 40...display device, 50...CPU, 60...memory, 70...I / O port, 100...rough terrain crane, 101...vehicle body, 110...rotating body, 120...boom, 121 ...Boom head, 130...wire rope, 140...hook, 150...tip sheave, 160...winch drum, 170...hook sheave, 180...over-hoisting prevention device, 200...overload prevention device, 220...rope area, 231...directly below position calculation unit, 232...line-shaped area calculation unit, 233...starting point setting unit, 234...calculation unit, 241...seed, 242...whisker, A...line-shaped area, D...direction, F...repulsive force, G...gravity direction, L...line, P0...directly below coordinate, P1...starting point

Claims

1. an image acquisition unit that acquires images from an imaging device that images a hook of the crane and a wire rope that is wound between the hook and the boom head; A segmentation unit that extracts a rope region including an image portion of the hook and the wire rope in the image based on the shading and color distribution of the image acquired by the image acquisition unit; a trajectory calculation unit that determines a vertical direction in the image based on position information of the imaging device, and determines a trajectory of the first mass point in the image when it is assumed that the first mass point moves inside the rope region extracted by the segmentation unit in the determined vertical direction or in the opposite direction to the determined vertical direction; a shape specifying unit that specifies a shape of the wire rope from the trajectory calculated by the trajectory calculation unit; A rope shape detection device comprising:

2. The trajectory calculation unit is a directly below position calculation unit that calculates a position directly below the boom head in an image captured by the imaging device based on imaging position information of the imaging device; a line-shaped area calculation unit that calculates a line-shaped area that is assumed to cross the upper end of the wire rope captured in the image captured by the imaging device based on the imaging position information; a starting point setting unit that sets the center of a crossing portion as a starting point each time the line-shaped area calculated by the line-shaped area calculation unit crosses the upper end portion of the rope area extracted by the segmentation unit; a calculation unit which determines a trajectory of the first mass point in the image when the direction from the origin set by the origin setting unit to the position directly below calculated by the directly below position calculation unit is defined as the vertical direction and the first mass point moves in the vertical direction along the rope region; having The rope shape detection device according to claim 1.

3. The trajectory calculation unit calculates the trajectory of the first mass point when it is assumed that the first mass point moves in the vertical direction or in the direction opposite to the vertical direction while being sandwiched between two second mass points from a direction perpendicular to the vertical direction, and that when one of the two second mass points deviates from the rope region, a repulsive force toward the other of the two second mass points is applied to the first mass point. The rope shape detection device according to claim 1 or 2.

4. The shape identification unit determines a length of the rope region in the vertical direction from the trajectory, and when the determined length is greater than a threshold value, determines a shape of the wire rope from the trajectory. The rope shape detection device according to any one of claims 1 to 3.

5. An imaging device provided on the boom head for imaging a wire rope suspended from a sheave of the boom head; A rope shape detection device according to any one of claims 1 to 4, A crane equipped with

6. An image acquiring step of acquiring an image from an imaging device that captures an image of a hook of the crane and a wire rope that is wound between the hook and the boom head; A segmentation step of extracting a rope region including an image portion of the hook and the wire rope in the image based on the shading and color distribution of the image acquired in the image acquisition step; a trajectory calculation step of determining a vertical direction in the image based on position information of the imaging device, and determining a trajectory of the first mass point in the image when it is assumed that the first mass point moves inside the rope region extracted in the segmentation step in the determined vertical direction or in a direction opposite to the determined vertical direction; a shape identification step of identifying a shape of the wire rope from the trajectory obtained in the trajectory calculation step; A rope shape detection method comprising:

7. A program for causing a computer to execute the wire rope shape detection method according to claim 6.

Images