Crane and detection method

Abstract

To provide a crane and a detection method capable of detecting an attitude of a sensor.SOLUTION: A method for detecting a posture of a sensor 6 in a crane 1 including a leg structure 2 including an upper girder 2b extending in a horizontal direction, a trolley 4 configured to be capable of traversing along the upper girder 2b, a hoisting accessory 5 suspended from the trolley 4 by a wire, and a sensor 6 installed in the trolley 4 to radiate electromagnetic waves toward the hoisting accessory 5 includes a measuring step in which the sensor 6 measures a current position of at least one adjustment target 9 installed in advance in the crane 1, and a comparison step in which a posture of the sensor 6 is calculated based on the current position obtained in the measuring step and an initial position of the target 9 set in advance.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a crane equipped with a sensor for measuring the position of a hoisting device and a detection method using the sensor, and more particularly to a crane that makes it possible to detect the attitude of the sensor and a method for detecting the attitude of the sensor. [Background technology]

[0002] Various cranes have been proposed that use sensors to measure the position of a hoisting device suspended from a trolley (see, for example, Patent Document 1). The crane described in Patent Document 1 was configured to measure the position of the hoisting device by using a sensor installed on the trolley to detect a target installed on the hoisting device.

[0003] The position of the sensor installed on the trolley can change over time. In particular, if the sensor tilts in the direction of the laser beam scanning, the accuracy of measuring the position of the sling decreases. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent No. 5314796 Summary of the Invention [Problem to be solved by the invention]

[0005] The present invention has been made in view of the above problems, and an object of the present invention is to provide a crane and a detection method that are capable of detecting the attitude of a sensor. [Means for solving the problem]

[0006] A crane for achieving the above-mentioned object comprises a leg structure including an upper girder extending horizontally, a trolley configured to be able to move laterally along the upper girder, a hoisting device suspended from the trolley by a wire, and a sensor installed on the trolley to irradiate electromagnetic waves toward the hoisting device, and is characterized in that the crane is equipped with at least one adjustment target installed on the crane and a control mechanism that acquires information from the sensor, and the control mechanism is configured to calculate the attitude of the sensor based on the current position of the target measured by the sensor and a predetermined initial position of the target.

[0007] A detection method for achieving the above-mentioned object is a method for detecting the attitude of a sensor in a crane that comprises a leg structure including an upper girder extending horizontally, a trolley configured to be able to move laterally along the upper girder, a hoisting device suspended from the trolley by a wire, and a sensor that is installed on the trolley and irradiates electromagnetic waves toward the hoisting device, and is characterized by comprising a measurement step in which the sensor measures the current position of at least one adjustment target that is installed in advance on the crane, and a comparison step in which the attitude of the sensor is calculated based on the current position obtained in the measurement step and the initial position of the target that is set in advance. [Effects of the Invention]

[0008] According to the present invention, the current position of the adjustment target relative to the sensor changes depending on the sensor's attitude. The amount of change in the sensor's attitude can be calculated by comparing the current position of the target with its initial position. This is advantageous for detecting the sensor's attitude with high accuracy. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 2 is an explanatory diagram illustrating a crane in perspective view. [Figure 2] FIG. 1 is an explanatory diagram illustrating a crane as viewed from the front. [Figure 3] FIG. 2 is an explanatory diagram illustrating the configuration of a control mechanism. [Figure 4]FIG. 10 is an explanatory diagram illustrating an example of how a target is detected. [Figure 5] FIG. 10 is an explanatory diagram illustrating the flow of a detection method. [Figure 6] FIG. 10 is an explanatory diagram illustrating an example of the relationship between the current position and the initial position of a target. [Figure 7] FIG. 10 is an explanatory diagram illustrating a target placed on a trolley. [Figure 8] FIG. 10 is an explanatory diagram illustrating an example of an external target installed on the travel surface. [Figure 9] 9 is an explanatory diagram illustrating FIG. 8 in plan view. [Figure 10] FIG. 10 is an explanatory diagram illustrating a flow of a modified example of a detection method. DETAILED DESCRIPTION OF THE INVENTION

[0010] The crane and detection method will be described below based on the embodiment shown in the drawings. In the drawings, the direction of travel of the crane is indicated by arrow y, the lateral direction perpendicular to the travel direction is indicated by arrow x, and the up-down direction is indicated by arrow z.

[0011] As shown in Figure 1, the crane 1 is, for example, a gantry crane. The crane 1 is not limited to a gantry crane, and may be any crane having a trolley that travels laterally along an upper girder. Specifically, the crane 1 may be a quay crane, an unloader, or an overhead crane.

[0012] The crane 1 comprises a leg structure 2 and a traveling device 3 that supports the leg structure 2 from below. The leg structure 2 comprises four leg members 2a extending in the vertical direction z, an upper girder 2b extending in the horizontal lateral direction x and connecting the upper ends of corresponding leg members 2a, and a lower girder 2c extending in the traveling direction y and connecting the lower ends of corresponding leg members 2a. The traveling device 3 has a plurality of wheels 3a and is configured to move the crane 1 along the traveling direction y. The crane 1 comprises a trolley 4 configured to be able to travel laterally along the upper girder 2b, and a hoisting device 5 suspended from the trolley 4 by a wire.

[0013] As shown in Figure 2, the crane 1 is equipped with a sensor 6 that is installed on the trolley 4. In this embodiment, the sensor 6 is installed on the underside of the trolley 4. The installation position of the sensor 6 is not limited to this, and the sensor 6 may be installed in another position on the trolley 4 as long as it is a position where electromagnetic waves can be emitted from the sensor 6 toward the hoisting device 5. Note that Figure 2 is a schematic front view of the crane 1.

[0014] The sensor 6 is configured to measure the position of the sling 5 by emitting electromagnetic waves, such as laser light, toward the sling 5. For the sake of explanation, the laser light emitted from the sensor 6 is shown by a dashed line in Figure 2. The sensor 6 is configured to emit multiple electromagnetic waves along the lateral direction x.

[0015] The sensor 6 may be configured to irradiate electromagnetic waves, including light, within a predetermined range. In this specification, light, including ultraviolet light, visible light, and infrared light, and radio waves, including microwaves, millimeter waves, and long waves, may be collectively referred to as electromagnetic waves.

[0016] The sensor 6 is configured as, for example, a two-dimensional laser scanner that scans with a laser beam along the lateral direction x. The sensor 6 may also be configured as a three-dimensional laser scanner. The sensor 6 may also be configured such that a sensor that irradiates a laser beam one-dimensionally is supported so as to be tiltable around the traveling direction y as a central axis.

[0017] The crane 1 performs a loading / unloading operation on a container 8 placed on the traveling surface 7 while moving on the traveling surface 7 in a traveling direction y by means of the traveling device 3.

[0018] The crane 1 is provided with at least one adjustment target 9 that is installed somewhere on the crane 1 , and a control mechanism 10 that acquires information from the sensor 6 .

[0019] The target 9 is formed of, for example, a circular plate-like member. The plate-like target 9 is installed, for example, in a direction perpendicular to the vertical direction z. The shape and installation direction of the target 9 are not limited to those described above, and it is sufficient that the shape and installation direction allow its position to be measured by the sensor 6. The shape of the target 9 may be rectangular or polygonal, or may be a three-dimensional shape such as a sphere or a rectangular parallelepiped. The installation direction of the target 9 may be such that the plate-like target 9 is installed in a direction perpendicular to the lateral direction x, or in a direction perpendicular to the lateral direction x and tilted at a predetermined angle with the traveling direction y as the central axis.

[0020] In this embodiment, the target 9 is installed on the leg member 2a of the leg structure 2. The position at which the target 9 is installed is not limited to this, and it may be any position that can be measured by the sensor 6.

[0021] The control mechanism 10 is installed on the trolley 4, for example. For the sake of explanation, the control mechanism 10 is shown by dashed lines in Figures 1 and 2. The control mechanism 10 is configured, for example, by a known PC or PLC (Programmable Logic Controller). However, the control mechanism 10 is not limited to this, and may be configured to be incorporated into the control device of the crane 1, the sensor 6, etc.

[0022] As illustrated in FIG. 3, the control mechanism 10 includes an acquisition unit 10a that acquires the current position P1 of the target 9 measured by the sensor 6 from the sensor 6, a memory unit 10b that stores the initial position P0 of the target 9, and a comparison unit 10c that compares the initial position P0 with the current position P1.

[0023] Next, we will explain how to detect the attitude of the sensor 6. The attitude of the sensor 6 is detected periodically. For example, the attitude of the sensor 6 is detected when the crane 1 is started or during periodic inspections that are carried out every predetermined period, such as every month or every six months.

[0024] As shown in the example of Figure 4, when detecting the attitude of the sensor 6, the sensor 6 scans electromagnetic waves, for example, along the horizontal direction x. Scanning refers to the emission of multiple electromagnetic waves from the sensor 6 at different angles along the horizontal direction x. The sensor 6 acquires data on the distance to the reflection point where the electromagnetic waves are reflected and the emission angle of the electromagnetic waves. For the sake of explanation, the direction in which the electromagnetic waves are emitted is indicated by an arrow in Figure 4. The scanning direction of the electromagnetic waves is also indicated by a dashed line.

[0025] 5, in the detection method of this embodiment, first, the trolley 4 moves to a preset measurement position Dx (movement step S01), and then the sensor 6 measures the current position P1 of the target 9 installed on the crane 1 (measurement step S02).

[0026] As shown in Figure 2, when the trolley 4 is stopped at a preset measurement position Dx, the sensor 6 measures the current position P1 of the target 9. The measurement position Dx is set in advance as the position in the lateral direction x on the upper girder 2b where the trolley 4 should stop. The measurement position Dx is set, for example, at the center of the upper girder 2b in the lateral direction x. The measurement position Dx is not limited to the above and may be any position at which the position of the target 9 can be measured by the sensor 6.

[0027] If the trolley 4 has already stopped at the measurement position Dx, the moving step S01 is not executed, and the measuring step S02 is executed instead. Therefore, the moving step S01 is not an essential component of the detection method.

[0028] 3, the acquisition unit 10a of the control mechanism 10 acquires the current position P1 of the target 9 measured by the sensor 6 as information from the sensor 6. The memory unit 10b of the control mechanism 10 stores the initial position P0 of the target 9 in advance.

[0029] As illustrated on the left side of Fig. 6, the initial position P0 refers to the relative position of the target 9 with respect to the sensor 6 when the sensor 6 is in the correct orientation. The initial position P0 can be obtained by measuring the target 9 with the sensor 6 in the correct orientation, for example, when the sensor 6 is first installed on the trolley 4. If the orientation of the sensor 6 changes, the position of the target 9 with respect to the sensor 6 will change from the initial position P0.

[0030] The comparison unit 10c of the control mechanism 10 calculates the attitude of the sensor 6 by comparing the initial position P0 stored in advance with the current position P1 acquired from the sensor 6 (comparison step S03).

[0031] For example, the right side of Fig. 6 shows an example of what happens when the attitude of the sensor 6 is tilted 5° clockwise around the traveling direction y as the central axis. When the attitude of the sensor 6 changes, the current position P1 of the target 9 acquired by the sensor 6 becomes different from the initial position P0, even though the position of the target 9 has not changed. For the sake of explanation, the initial position P0 of the target 9 is shaded on the right side of Fig. 6.

[0032] By comparing the initial position P0 and the current position P1 of the target 9, the comparison unit 10c can calculate the change in the attitude of the sensor 6. The control mechanism 10 obtains a result such as that the sensor 6 is tilted 5° clockwise with the traveling direction y as its central axis.

[0033] Next, based on the change in the attitude of the sensor 6 obtained in the comparison step S03, the attitude of the sensor 6 is adjusted to the correct attitude (adjustment step S04). In the adjustment step S04, for example, an operator moves close to the sensor 6 and adjusts the sensor 6 by tilting it counterclockwise by 5°.

[0034] The control mechanism 10 may be configured to generate correction information q1 for correcting information obtained from the sensor 6 based on a change in the attitude of the sensor 6 (correction information generation step S05). For example, the correction information q1, such as 5° counterclockwise, is generated by the control mechanism 10 and stored in the storage unit 10b.

[0035] The control mechanism 10 corrects the position of the hoisting device 5 measured by the sensor 6 based on the correction information q1. This correction enables the control mechanism 10 to calculate the correct position of the hoisting device 5, eliminating the influence of changes in the attitude of the sensor 6. The correction using the correction information q1 may be configured to be performed by the sensor 6. In this case, the correction information q1 is sent from the control mechanism 10 to the sensor 6. When the correction information generation step S05 is executed, the adjustment step S04 for adjusting the installation position of the sensor 6 is not executed.

[0036] In some cases, it may be determined in the comparison step S03 that the attitude of the sensor 6 has not changed. In this case, neither the adjustment step S04 nor the correction information generation step S05 is executed. The adjustment step S04 and the correction information generation step S05 are not essential components of the detection method.

[0037] According to the above-described configuration, the crane 1 can calculate the amount of change in the attitude of the sensor 6 by comparing the initial position P0 of the target 9 with the current position P1. This makes it possible to detect the attitude of the sensor 6 with the traveling direction y as its central axis. Based on the calculated amount of change in the attitude of the sensor 6, the worker can adjust the attitude of the sensor 6 or correct the position measured by the hoisting tool 5 using correction information q1. This is advantageous for maintaining accuracy when measuring the position of the hoisting tool 5 by the sensor 6.

[0038] A configuration may be adopted in which either adjustment step S04 or correction information generation step S05 is executed depending on the amount of change in the attitude of the sensor 6. If the amount of change in the attitude of the sensor 6 exceeds a preset threshold, adjustment step S04 is executed, and if the amount of change is equal to or less than the threshold, correction information generation step S05 is executed. For example, a configuration may be adopted in which adjustment step S04 is executed if the amount of change in the tilt of the sensor 6 with respect to the traveling direction y as the central axis exceeds 2°, and correction information generation step S05 is executed in other cases. This is advantageous for maintaining the accuracy of measuring the position of the hoisting device 5 without interfering with the loading and unloading operations by the crane 1 as much as possible.

[0039] Also, depending on when the periodic inspection is performed, either the adjustment step S04 or the correction information generation step S05 may be executed. For example, the adjustment step S04 may be executed during the periodic inspection, and the correction information generation step S05 may be executed at other times. Since the attitude of the sensor 6 can be adjusted during the periodic inspection when the crane 1 is in a stopped state, it is possible to prevent the loading and unloading operation of the crane 1 from being hindered.

[0040] As shown in FIG. 1, the target 9 may be configured to extend in the traveling direction y of the crane 1 and be installed on the lower girder 2c that constitutes the lower end of the leg structure 2. Even if deformation such as strain occurs in the leg structure 2 of the crane 1, the lower girder 2c, which is located relatively close to the traveling surface 7, is less likely to be affected by this deformation. The current position P1 of the target 9 is hardly affected by the deformation of the crane 1. This is advantageous for improving the accuracy when detecting the attitude of the sensor 6.

[0041] The location where the target 9 is placed is not limited to the above. The target 9 may be placed on a leg member 2a extending in the vertical direction z. A horizontal member, stairs for ascending and descending, or the like may be placed between a pair of leg members 2a opposed to each other with a gap in the traveling direction y. The target 9 may be placed on this horizontal member, stairs, or the like.

[0042] As illustrated in Fig. 7, the target 9a may be configured to be installed on the trolley 4. In this embodiment, the plate-shaped target 9a is installed on the underside of the trolley 4 in a direction perpendicular to the lateral direction x. In the measurement step S02, the sensor 6 measures the current position P1 of the target 9a installed on the trolley 4. For example, during loading and unloading operations of the crane 1, the sensor 6 scans electromagnetic waves onto the hoisting device 5. At the same time, the sensor 6 measures the position of the target 9a.

[0043] This configuration allows the crane 1 to improve the accuracy when detecting the attitude of the sensor 6. Because both the sensor 6 and the target 9a are mounted on the trolley 4, the current position P1 of the target 9a is not affected by deformation of the leg structure 2. For example, if the target 9 is mounted on the leg member 2a and the leg member 2a deforms due to aging, the position of the target 9 relative to the sensor 6 will change. In this case, even if the sensor 6 is in the correct attitude, a change in the attitude of the sensor 6 will be detected in comparison step S03. In contrast, when the target 9a is mounted on the trolley 4, it is not affected by deformation of the leg structure 2, and a change in the attitude of the sensor 6 will not be detected in comparison step S03. This is advantageous for improving the accuracy when detecting the attitude of the sensor 6.

[0044] Furthermore, with the above-described configuration, the crane 1 can improve the frequency with which it measures the target 9a. Because the target 9a is mounted on the trolley 4, it moves integrally with the trolley 4. The relative position between the sensor 6 and the target 9a remains constant regardless of the position of the trolley 4 on the upper girder 2b. The sensor 6 can measure the current position P1 of the target 9a at any time. Therefore, the movement step S01 of moving the trolley 4 to the measurement position Dx before executing the measurement step S02 is not necessary. This is advantageous for improving the frequency with which the measurement step S02 is executed. Specifically, during loading and unloading operations of the crane 1, the sensor 6 can measure the current position P1 of the target 9a every time it measures the position of the hoisting device 5.

[0045] The number of targets 9 installed on the crane 1 is not limited to one. The crane 1 may be configured to have multiple targets 9 installed. In this case, the control mechanism 10 is configured to control the sensor 6 to measure the current positions P1 of the multiple targets 9. The crane 1 may include, for example, a target 9a installed on the trolley 4 and a target 9b installed on the lower girder 2c.

[0046] In this embodiment, first, in a movement step S01, the trolley 4 moves to the measurement position Dx. In a measurement step S02, the sensor 6 measures the current position P1 of both the target 9a attached to the trolley 4 and the target 9b attached to the lower beam 2c. In a comparison step S03, the initial position P0 and the current position P1 are compared for each of the two targets 9a and 9b. If the comparison results in the same result for both targets 9a and 9b, for example, the sensor 6 is tilted counterclockwise by 1°, it can be determined that the attitude of the sensor 6 has changed.

[0047] If the results obtained in comparison step S03 are different for the two targets 9a and 9b, it can be seen that deformation has occurred in the leg structure 2, etc., between the trolley 4 and the lower girder 2c. For example, the sensor 6 may result in a tilt of 1° counterclockwise with respect to the target 9a of the trolley 4, and in a tilt of 2° counterclockwise with respect to the target 9b of the lower girder 2c. In this case, it can be said that deformation equivalent to a tilt of 1° counterclockwise has occurred in the leg structure 2 between the trolley 4 and the lower girder 2c.

[0048] By using a configuration in which multiple targets 9 are measured by the sensor 6, it is possible to calculate the effect of deformation of the leg structures and the like between the targets 9. It is possible to separately acquire the amount of change in the attitude of the sensor 6 and the amount of deformation of the crane 1. This is advantageous for improving the accuracy in detecting the attitude of the sensor 6. It also makes it possible to grasp the amount of deformation of the crane 1. This amount of deformation of the crane 1 can be used for periodic inspections and repair work of the crane 1.

[0049] Furthermore, it is possible to remove the influence of deformation of the crane 1 from the correction information q1 generated in the correction information generating step S05, which is advantageous in improving the accuracy of the correction information q1.

[0050] The positions at which the multiple targets 9 are installed are not limited to those described above. For example, a configuration may be adopted in which a target 9b is installed on each of a pair of lower girders 2c that are spaced apart in the lateral direction x. Three or more targets 9 may be installed on the crane 1. For example, a configuration may be adopted in which a target 9a is installed on the trolley 4, and a target 9b is installed on each of the pair of lower girders 2c.

[0051] The detection method is not limited to a method of simultaneously measuring the current positions P1 of multiple targets 9 in the measurement step S02. Here, "simultaneously" means that the current positions P1 of multiple targets 9 are measured in a single scan when the sensor 6 scans electromagnetic waves along the lateral direction x. A configuration may be adopted in which the measurement step S02 and comparison step S03 are performed for one target 9, and then the measurement step S02 and comparison step S03 are performed for the other target 9.

[0052] As illustrated in FIGS. 8 and 9 , the control mechanism 10 may be configured to measure, using a sensor 6, the current position P1 of an external target 9c installed on the travel surface 7 of the crane 1, in addition to the target 9b installed on the crane 1. The external target 9c is installed at a position above the travel surface 7. In this embodiment, the external target 9c is supported by a support member 11 installed on the travel surface 7. The plate-shaped external target 9c is arranged in a direction perpendicular to the lateral direction x. The external target 9c is also arranged at a position on the outside of the pair of leg members 2a in the lateral direction x. The external target 9c may also be arranged at a position on the inside of the pair of leg members 2a that does not interfere with the placement of the container 8 or the movement of the vehicle loading and unloading the container 8. The external target 9c may also be configured to be installed directly on the travel surface 7 without the support member 11.

[0053] In this embodiment, the target 9b installed on the crane 1 is installed on the leg member 2a. The plate-shaped target 9b is arranged in a direction perpendicular to the vertical direction z. As illustrated in Fig. 9, the target 9b is installed at a position that is the midpoint between the pair of leg members 2a in the traveling direction y.

[0054] As illustrated in FIG. 9, the crane 1 first moves to a measurement position Dy, which is a position when measuring the external target 9c with the sensor 6 (movement step S01). The measurement position Dy is set in advance as a position in the traveling direction y where the crane 1 should stop on the traveling surface 7. In this movement step S01, the trolley 4 moves to a predetermined measurement position Dx. The measurement positions Dx and Dy are set in advance at positions where the current position P1 of the external target 9c can be measured by the sensor 6. In the movement step S01, the crane 1 stops at the measurement position Dy in the traveling direction y, and the trolley 4 stops at the measurement position Dx in the lateral direction x.

[0055] After the moving step S01, a measuring step S02 and a comparing step S03 are performed on the target 9b installed on the crane 1 and the external target 9c installed on the travel surface 7.

[0056] This configuration makes it possible to accurately separate the effects of deformation of the crane 1 from the measurement results. The current position P1 of the external target 9c installed on the travel surface 7 is not affected by deformation of the crane 1. By comparing the measurement results of the external target 9c installed on the travel surface 7 and the target 9b installed on the crane 1, the amount of deformation of the crane 1 can be accurately determined.

[0057] In the correction information generation step S05, it is possible to obtain correction information q1 that does not include the influence of the deformation of the crane 1. By using this correction information q1, when performing the measurement step S02 and the comparison step S03 for the target 9b placed on the crane 1, it is possible to obtain results that exclude the influence of the deformation of the crane 1. This also improves the accuracy of detecting the attitude of the sensor 6 using only the target 9b placed on the crane 1. In this case, the crane 1 can accurately detect the attitude of the sensor 6 using only the target 9b without moving to the measurement position Dy.

[0058] As illustrated in Fig. 10, the detection method may be configured to detect the posture of the sensor 6 in multiple stages for each target 9. In this embodiment, the targets 9 are, for example, composed of a target 9a installed on the trolley 4 and a target 9b installed on the leg structure 2. The detection method detects the posture of the sensor 6 in two stages: a first stage step S10 in which the target 9a on the trolley 4 is detected, and a second stage step S20 in which the target 9b installed on the leg structure 2 is detected.

[0059] In the first stage step S10, for example, each time the position of the hoisting device 5 is measured, the current position P1 of the target 9a attached to the trolley 4 is measured (measurement step S02), and this current position P1 is compared with the initial position P0 (comparison step S03). The first stage step S10 does not include the movement step S01.

[0060] The first level step S10 is repeatedly executed during loading and unloading operations by the crane 1. The second level step S20 is executed when a change in the posture of the sensor 6 is detected as a result of the comparison step S03. The determination of whether to proceed to the second level step S20 is not limited to the above.

[0061] 1, a transition to the second layer step S20 may be determined depending on the amount of change in the attitude of the sensor 6. Specifically, if the amount of change in the attitude of the sensor 6 does not exceed a threshold, a measure using correction information q1 may be taken (correction information generation step S05), and if the amount of change in the attitude of the sensor 6 exceeds the threshold, a transition to the second layer step S20 may be made.

[0062] 1, the second-level step S20 may be executed during regular inspections, and the first-level step S10 may be repeatedly executed otherwise. In this case, if a change in the attitude of the sensor 6 is detected in the first-level step S10, a response may be made using correction information q1 (correction information generation step S05).

[0063] In the second-floor step S20, the trolley 4 is moved laterally to the measurement position Dx regardless of the position of the crane 1 (movement step S01). Then, a measurement step S02 and a comparison step S03 are performed for the target 9b installed on the leg structure 2. Depending on the amount of change in the attitude of the sensor 6 obtained in the comparison step S03, an adjustment step S04 or a correction information generation step S05 is performed. Specifically, if the amount of change in the attitude of the sensor 6 exceeds a preset threshold, the adjustment step S04 is performed, and if it is equal to or less than the threshold, the correction information generation step S05 is performed. The correction information q1 generated in the correction information generation step S05 can be used to measure the position of the hoisting device 5 later and in the measurement step S02 in the first-floor step S10.

[0064] The detection method may include a configuration for executing a third-level step S30 for detecting an external target 9c installed on the travel surface 7. In the third-level step S30, the crane 1 moves to a measurement position Dy, and the trolley 4 moves to a measurement position Dx (movement step S01). Thereafter, a measurement step S02 and a comparison step S03 are executed for the external target 9c. The detection method may be configured, for example, in two steps, a first-level step S10 and a third-level step S30, or in two steps, a second-level step S20 and a third-level step S30.

[0065] The movement step S01 is not required in the first floor step S10, the trolley 4 needs to be moved in the second floor step S20, and the trolley 4 and crane 1 need to be moved in the third floor step S30. Therefore, the order of the first floor step S10, the second floor step S20, and the third floor step S30 makes it easier to improve the frequency of detecting the current position P1 of the target 9. The order of the third floor step S30, the second floor step S20, and the first floor step S10 makes it easier to eliminate the effects of deformation of the leg structure 2, etc.

[0066] With this configuration, the crane 1 can execute the first-level step S10, which utilizes the target 9a mounted on the trolley 4, relatively frequently. Furthermore, since the second-level step S20 is executed after a change in the attitude of the sensor 6 is confirmed in the first-level step S10, the crane 1 can reduce the possibility of performing unnecessary measurements. For example, the crane 1 will not encounter a situation in which the sensor 6 is still in the correct attitude even after interrupting loading and unloading operations and executing the second-level step S20. Furthermore, by executing the second-level step S20, the crane 1 can detect the attitude of the sensor 6 with relatively high accuracy.

[0067] In addition, the crane 1 can acquire correction information q1 that suppresses the influence of deformation of the leg structure 2, etc. By using the correction information q1 obtained in the second-level step S20, the crane 1 can improve the detection accuracy of the attitude of the sensor 6 in the first-level step S10.

[0068] The detection method may have a configuration in which the first-level step S10 is followed by the second-level step S20, and then the third-level step S30 is executed. In this case, the posture of the sensor 6 is detected in three stages. The detection method may have a configuration in which the first-level step S10 is repeatedly executed during loading and unloading operations by the crane 1, the second-level step S20 is executed during periodic inspections such as one-month inspections, and the third-level step S30 is executed during long-term periodic inspections such as six-month inspections.

[0069] By performing operations that do not increase the frequency of detection of the target 9, such as moving the trolley 4 to the measurement position Dx or moving the crane 1 to the measurement position Dy, as the subsequent second level step S20 or third level step S30, the accuracy of detecting the posture of the sensor 6 can be improved while suppressing a decrease in the efficiency of the loading and unloading work of the crane 1. [Explanation of symbols]

[0070] 1 crane 2 leg structure 2a Leg member 2b Upper girder 2c Lower girders 3 Running gear 3a wheels 4 Trolley 5 Hanging equipment 6 sensors 7 Running surface 8 Containers 9 Target 9a Target (mounted on a trolley) 9b Target (mounted on a crane) 9c External target (mounted on the running surface) 10 Control Mechanism 10a Acquisition part 10b Storage section 10c Comparison section 11 Support member x transverse direction y Travel direction z Vertical direction Dx measurement position Dy measurement position S01 Movement step S02 Measurement step S03 Comparison step S04 Adjustment step S05 Correction information generation step S10 First level step S20 Second layer step S30 Third level step P0 initial position P1 Current position q1 Correction information

Claims

1. A crane comprising: a leg structure including an upper girder extending in a horizontal direction; a trolley configured to be able to move laterally along the upper girder; a hoisting device suspended from the trolley by a wire; and a sensor installed on the trolley to irradiate electromagnetic waves toward the hoisting device, At least one adjustment target is installed on the crane, and a control mechanism is provided that acquires information from the sensor, The crane is characterized in that the control mechanism has a configuration that calculates the attitude of the sensor based on the current position of the target measured by the sensor and a preset initial position of the target.

2. The target is configured to be mounted on the leg structure, The crane of claim 1 , wherein the trolley has a measurement position where it stops when the sensor measures the target.

3. 3. The crane according to claim 2, wherein the target is configured to extend in the direction of travel of the crane and to be installed on a lower girder that constitutes the lower end of the leg structure.

4. The crane of claim 1 , wherein the target is configured to be mounted on the trolley.

5. The crane according to any one of claims 1 to 4, wherein the control mechanism is configured to control the sensors to measure current positions of the plurality of targets.

6. the control mechanism has a configuration for controlling the sensor to measure a current position of at least one of the targets installed on the crane as well as an external target installed on a travel surface of the crane; The crane according to any one of claims 1 to 4, wherein the crane has a measurement position where it stops when measuring the external target with the sensor.

7. A method for detecting the attitude of a sensor in a crane including a leg structure including an upper girder extending in a horizontal direction, a trolley configured to be able to move laterally along the upper girder, a hoisting device suspended from the trolley by a wire, and a sensor installed on the trolley to irradiate electromagnetic waves toward the hoisting device, a measuring step in which the sensor measures a current position of at least one adjustment target that is pre-installed on the crane; A detection method comprising a comparison step of calculating the attitude of the sensor based on the current position obtained in the measurement step and a preset initial position of the target.

8. A moving step of moving the trolley to a preset measurement position is provided, 8. The detection method according to claim 7, wherein the measuring step includes a step of measuring a current position of the target, which is previously set on the leg structure, by the sensor after the moving step.

9. 8. The detection method according to claim 7, wherein the measuring step includes a configuration in which the sensor measures the current position of the target that is pre-installed on the trolley.

10. The measuring step includes a configuration in which the sensor measures current positions of the targets, 10. The detection method according to claim 7, wherein the comparing step includes calculating the attitude of the sensor based on the current position and the initial position of each of the targets.

11. A moving step is provided for moving the crane and the trolley to respective preset measurement positions, The detection method according to any one of claims 7 to 9, wherein the measuring step is configured such that, after the moving step, the sensor measures the current position of an external target installed on the travel surface of the crane in addition to at least one of the targets installed in advance on the crane.

12. A first stage step including a measurement step in which the sensor measures the current position of the target pre-installed on the trolley, and a comparison step executed using the current position obtained in this measurement step; The detection method described in claim 7, further comprising a second hierarchical step including a measurement step in which the sensor measures the current position of the target installed on the leg structure or an external target installed on the running surface of the crane based on the results of the first hierarchical step, and a comparison step performed using the current position obtained in this measurement step.

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