crane

Abstract

To provide a crane capable of more effectively suppressing shaking of a suspended article while conveyance work of the article is stopped.SOLUTION: The crane comprises: a boom; and a suspended article 16 suspended from the boom. The crane performs, on plane coordinates seen vertically downward from above the crane, with a position where the article 16 is suspended from the boom without being shaken set as a reference position of the article 16, first control for operating the boom 2 to approach a first misaligned position 16a1 on the plane coordinates when the article 16 is at the first misaligned position 16a1 misaligned from a first reference position, and second control for operating the boom 2 to approach a second misaligned position 16a2 on the plane coordinates when the article 16 is at the second misaligned position 16a2 misaligned from a second reference position which is a reference position after the first control.SELECTED DRAWING: Figure 6

Description

Technical Field

[0001] The present invention relates to a crane.

Background Art

[0002] Conventionally, technologies for transporting a suspended object (hook, hook and suspended load hooked to the hook) to a predetermined position while suppressing the swing of the suspended object have been developed (see Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, there has been a demand for a crane that can more effectively suppress the swing of a suspended object when the conveyance operation of the suspended object stops and the suspended object is swinging due to some cause (for example, residual vibration at the time of stop, earthquake, wind, etc.).

[0005] An object of the present invention is to provide a crane that can more effectively suppress the swing of a suspended object when the conveyance operation of the suspended object stops.

Means for Solving the Problems

[0006] The crane according to the present invention includes a boom and a suspended object suspended from the boom , a detection unit that detects objects around the suspended object and, has . The crane according to the present invention has the following: In a planar coordinate system viewed vertically downward from above the crane, if the position where the suspended object is suspended from the boom without swaying is taken as the reference position of the suspended object, then when the suspended object is at a first misaligned position that is shifted from the first reference position, the crane performs a first control to move the boom closer to the first misaligned position in the planar coordinate system; and when the suspended object is at a second misaligned position that is shifted from the second reference position, which is the reference position after the first control, the crane performs a second control to move the boom closer to the second misaligned position in the planar coordinate system. i) The first control is performed such that, with respect to the object among the objects detected by the detection unit that has the potential to come into contact with the suspended object, the first displacement position is located on the opposite side of the first reference position. It is designed that way. [Effects of the Invention]

[0007] The crane of the present invention can more effectively suppress the swinging of suspended objects when the transport operation of the suspended objects is stopped. [Brief explanation of the drawing]

[0008] [Figure 1] This is a side view of a crane according to an embodiment of the present invention. [Figure 2] This is a plan view showing a crane according to an embodiment of the present invention, with some parts omitted. [Figure 3] Figure 1 is a partially enlarged view of the crane shown. [Figure 4] This is a block diagram showing the functional configuration of a crane according to an embodiment of the present invention. [Figure 5] This is a simplified plan view showing the relationship between the position of the suspended object at its maximum amplitude and the surrounding structures at the work site. [Figure 6] This figure shows the first example of a method for preventing swaying of suspended objects. [Figure 7] Figure 7(a) is a plan view showing a second example of a suspension method for preventing swaying of suspended objects, and Figure 7(b) is a plan view showing a third example of a suspension method for preventing swaying of suspended objects. [Figure 8] This is a flowchart illustrating the process of preventing swaying of suspended objects. [Modes for carrying out the invention]

[0009] Embodiments of the present invention will be described in detail below with reference to the drawings.

[0010] (Crane configuration) Figure 1 is a side view of the crane 1 according to this embodiment. Figure 2 is a plan view of the crane 1 according to this embodiment of the present invention, with some parts (boom 2, luffing rope 3, etc.) omitted. Figure 3 is a partially enlarged view of the crane 1 shown in Figure 1, and shows the mounting structure of the camera 4. As shown in Figures 1 and 2, the crane 1 is a so-called mobile crawler crane. Specifically, the crane 1 comprises a self-propelled crawler-type lower vehicle 5 and an upper rotating vehicle 6 that is rotatably mounted on the lower vehicle 5. In the following explanation, the front, back, left, and right directions as seen from the perspective of the person operating crane 1 will be described as the front, back, left, and right directions of crane 1.

[0011] A boom 2 is mounted on the front of the upper slewing body 6 so that it can be raised and lowered. A counterweight 7 is mounted on the rear of the upper slewing body 6 to balance the weight of the boom 2 and the suspended load. A cabin 8 is located on the right front of the upper rotating body 6, where the operator sits and controls the crane 1.

[0012] The luffing motion of boom 2 is performed by winding in or unwinding the luffing rope 3 using the luffing winch 10.

[0013] One end of the hoisting rope 11 is connected to a hook 12, and the hook 12 is suspended by the hoisting rope 11 which is wound around a point sheave 17 at the tip of the boom 2. The other end of the hoisting rope 11 is wound around a hoisting winch 13 on the upper slewing body 6, and the hoisting rope 11 is wound in or unwound by the drive of the hoisting winch 13, causing the hook 12 to rise and fall. The suspended load 14 is suspended from the hook 12 by a suspension material 15 such as a string or chain. In this embodiment, the hook 12 and the suspended load 14 constitute a suspended object 16 that is suspended from the boom 2. For the sake of explanation, the portion of the hoisting rope 11 that extends from the point sheave 17 to the hook 12 will be referred to as the load rope 11a, and the length of this load rope 11a will be referred to as the rope length. Furthermore, if the load 14 is not suspended from the hook 12, the suspended object 16 will consist only of the hook 12.

[0014] The crane 1 shown in Figure 1 represents the state when the transport operation of the suspended object 16 has stopped. The suspended object 16 is located vertically below the center 17a of the point sheave 17 positioned at the tip of the boom 2 and is suspended by the load rope 11a without any swaying. In the crane 1 shown in Figure 1, the position assumed to be where the suspended object 16 is suspended from the boom 2 without any swaying (the position on the reference line VL extending vertically downward from the center 17a of the point sheave 17) is taken as the reference position of the suspended object 16. For the sake of explanation, the center 17a of the point sheave 17 is taken as the suspension position of the suspended object 16 on the boom 2. Furthermore, in the crane 1 shown in Figure 2, when considering the lateral swaying of the suspended object 16 (along the Y-axis), the position assumed to be where the suspended object 16 is suspended from the boom 2 without any swaying (the position on the imaginary line extending vertically downward from the lateral center position of the point sheave 17) is taken as the reference position. Furthermore, in the crane 1 shown in Figure 1, "operational operation" refers to the time when the boom 2 is moved relative to the ground surface of the crane 1, or when the suspension rope 11a is moved to move the suspended object 16 to a predetermined location. For example, "operational operation" refers to the time when the crane 1 is luffed, rotated, or when the suspension rope 11a is hoisted up or down. Also, "operational operation" does not include the time when the crane 1 is monitoring its surroundings using the surrounding monitoring device, for example, if the crane 1 has a surrounding monitoring device.

[0015] As shown in FIGS. 1 and 3, a camera 4 as a detection unit is suspended via a fixture 18 on the tip side of the boom 2. The fixture 18 has a base 20 fixed to the boom 2, a support column 21 whose one end is rotatably supported by this base 20, and a cover 22 fixed to the other end of the support column 21. This fixture 18 maintains a downward-facing posture by its own weight regardless of the raising and lowering operation of the boom 2. Inside the cover 22, the camera 4 is housed. As a result, the camera 4 maintains a downward-facing posture like the support column 21 and the cover 22 of the fixture 18 regardless of the raising and lowering operation of the boom 2.

[0016] The camera 4 is configured to image the suspended object 16 and the work site around the suspended object 16 and transmit the acquired image data to the control unit 23.

[0017] FIG. 4 is a block diagram showing the functional configuration of the crane 1. As shown in this FIG. 4, in addition to the above configuration, the crane 1 includes a control unit 23, a drive unit 24, an operation unit 25, a display unit 26, a communication unit 27, a camera (detection unit) 4, and a storage unit 28.

[0018] The control unit 23 is composed of, for example, a CPU (Central Processing Unit) or the like, and controls the operations of each part of the crane 1. The control unit 23 includes the functions of an ECU (Electronic Control Unit) and is arranged on the upper swing body 6. Specifically, the control unit 23 operates the drive unit 24 based on the operator's operation input or the like, and executes various processes in cooperation with a program 31 (31a to 31c) or the like stored in advance in the storage unit 28 described later.

[0019] The drive unit 24 is a drive source for operating each part of the crane 1, and includes the above-described hoisting winch 10, the hauling winch 13, the turning device 30 of the upper swing body 6, and various other motors and actuators. The control unit 25 is an operating means that the operator uses to perform various operations. The control unit 25 includes, for example, a handle, pedals, levers, various buttons, etc., and outputs operation signals to the control unit 23 according to the content of these operations.

[0020] The display unit 26 is, for example, a liquid crystal display, an organic electroluminescent display, or other display, and displays images of the suspended object 16 and the work site around the suspended object 16, as well as various information, based on display signals input from the control unit 23. The display unit 26 may also be a touch panel that also serves as part of the operation unit 25. The communication unit 27 is a communication device capable of sending and receiving various types of information with, for example, an information terminal (not shown).

[0021] As described above, the camera 4, acting as a detection unit, outputs image data of the suspended object 16 and the work site surrounding the suspended object 16 to the control unit 23. Furthermore, if the camera 4 has a distance measuring function, it acquires distance data to the suspended object 16 and outputs this distance data to the control unit 23. The detection unit may use a monocular camera, a stereo camera, a laser sensor such as LiDAR, or a GNSS (Global Navigation Satellite System). Also, the distance data to the suspended object 16 is the distance data from the camera 4 to the hook 12 when the load 14 is not suspended from the hook 12. Alternatively, even when the load 14 is suspended from the hook 12, the distance data to the suspended object 16 may be the distance data from the camera 4 to the hook 12. In this embodiment, the camera 4 is positioned at the tip of the boom 2, but is not limited to this position; it can be positioned at a location where image data of the suspended object 16 and the work site surrounding the suspended object 16 can be acquired (for example, the middle part of the boom 2, the lower end of the boom 2, or the upper slewing body 6).

[0022] The memory unit 28 is a memory composed of, for example, RAM (Random Access Memory) or ROM (Read Only Memory), and stores various programs and data, as well as functioning as a work area for the control unit 23. The memory unit 28 in this embodiment pre-stores a sway-prevention processing program 31 for executing the sway-prevention processing of the suspended object 16 (see Figure 8), which will be described later. This sway-prevention processing program 31 includes a suspended object position measurement program 31a, an obstacle detection program 31b, and a boom operation control program 31c.

[0023] The suspended object position measurement program 31a uses image data acquired by camera 4 to calculate the maximum amplitude, direction of swing, and period of swing of the suspended object 16.

[0024] The obstacle detection program 31b uses image data acquired by camera 4 to detect obstacles (objects) that may collide with the suspended object 16 and determines the direction of sway suppression for the suspended object 16. For example, the obstacle detection program 31b uses image data acquired by camera 4 to calculate the horizontal distance (shortest distance in the XY plane in Figure 5) L between the position of the suspended object 16 at its maximum amplitude and a surrounding structure (object) 32 at the work site. Then, the obstacle detection program 31b compares the horizontal distance L with a predetermined control dimension La, and if the horizontal distance L is the same as or smaller than the control dimension La, it identifies the surrounding structure (object) 32 as an obstacle. Next, the obstacle detection program 31b determines the direction of sway suppression for the suspended object 16 in the sway suppression process described later to be away from the obstacle (32) (the -X direction in Figure 5), and moves the suspension position (17a) of the boom 2 in the first control described later in the direction away from the obstacle (32).

[0025] The boom operation control program 31c calculates the slewing angle and / or elevation angle of the boom 2 to suppress the swing of the suspended object 16, based on the calculation results of the suspended object position measurement program 31a and the determination results of the obstacle detection program 31b.

[0026] (Example of vibration damping treatment) Figure 6 shows a first example of the sway-damping treatment for the suspended object 16, and illustrates the case where the maximum amplitude direction of the suspended object 16 is along the X-axis direction, representing vibration pattern I. Figure 6 also shows the sway-damping treatment for the suspended object 16 when no obstacle (32) is detected by the obstacle detection program 31b. Figure 6(a) is a plan view showing the first example of the sway-damping treatment for the suspended object 16, and Figure 6(b) is a side view showing the first example of the sway-damping treatment for the suspended object 16.

[0027] As shown in Figure 6, the boom operation control program 31c focuses on the fact that vibrations of the suspended object 16 are suppressed when the center 17a of the point sheave 17 (which is the pivot point for the amplitude of the suspended object 16 and the suspension position of the suspended object 16 to the boom 2) is brought closer to the position of maximum amplitude of the suspended object 16 (a position shifted from the reference position, which is a position on the reference line VL), and calculates the elevation angle of the boom 2.

[0028] In this embodiment, the sway suppression of the suspended object 16 is performed in two stages, illustrating a case where the amplitude of the vibration of the suspended object 16 is less than or equal to a predetermined set value (see steps S4 to S9 in Figure 8). Specifically, the first control, which is the first sway suppression, is performed when the suspended object 16 is moving from a reference position (first reference position) on the reference line VL (first reference line (VL1)) toward the position of maximum amplitude. In this first control, when the suspended object 16 is at a first misaligned position 16a1, which is shifted from the first reference position, the boom operation control program 31c calculates the luffing angle of the boom 2 based on the calculation results of the suspended object position measurement program 31a (maximum amplitude, direction of swing, period of swing of the suspended object 16), so that the boom 2 approaches the first misaligned position 16a1 (so that the suspension position 17a moves to a suspension position 17a1 at a distance of m1 from the position on the first reference line (VL1) (on the second reference line VL2)). This first control is performed when the crane 1 is not in operation, and the suspension position (17a) is brought closer to the suspended object 16. Then, the control unit 23 operates the luffing winch 10 based on the calculation results of this boom operation control program 31c to luff the boom 2. Furthermore, boom 2 is lowered when moving the suspension position (17a) toward the tip in the +X direction, and raised when pulling the suspension position (17a) back from the tip in the +X direction. In this first control, the timing of the movement of the suspension position (17a) is when the suspended object 16 is moving from the reference position on the first reference line VL1 to the position of maximum amplitude. By moving at this timing, boom 2 can be moved in the same direction as the movement of the suspended object 16, making it easier to suppress the swing. In addition, between this first control and the second control described later, there is a neutral state (neutral brake state) in manual operation. In this case (neutral brake state), if it is a hydraulic crane, the hydraulic brake will be applied to the operation of crane 1. The set value of the amplitude of the suspended object 16 can be arbitrarily determined according to the conditions of the work site, etc.

[0029] The second control, which is the second time the suspended object 16 is suspended, is controlled in the opposite direction to the first control. When the suspended object 16 is at a second misaligned position 16a2, which is a deviation from the second reference position on the second reference line Vl2, which is the reference position after the first control, the boom 2 is operated to move closer to the second misaligned position 16a2. In other words, this second control calculates the distance m2 (distance to the suspension position (17a2)) from the suspension position (17a1) at the end of the first control to the next suspension object 16's maximum amplitude position (second misaligned position 16a2) using the boom operation control program 31c, and also calculates the luffing angle of the boom 2 corresponding to the distance m2 using the boom operation control program 31c. Based on the calculation result of this boom operation control program 31c, the control unit 23 operates the luffing winch 10 to luff the boom 2. In this second control, the timing of the movement of the suspension position (17a1) is when the suspended object 16 has moved from the second reference position on the second reference line VL2 at the suspension position (17a1) at the end of the first control to the position of maximum amplitude (at a distance m2). Furthermore, the second control is not limited to control in the opposite direction to the first control, and the suspension position (17a1) at the end of the first control may be moved in accordance with the direction of movement of the suspended object 16 returning to the first misaligned position 16a1 (it may also be controlled in the same direction as the first control). In other words, the second control may be performed in the same direction as the first control after the suspended object 16 has passed the second reference line (VL2) twice, after the suspension has entered a neutral state (neutral brake state) between the first and second controls.

[0030] In this method of preventing the suspension of the suspended object 16 from swaying, the sway prevention is performed in multiple steps. Compared to the case where the sway prevention is performed in a single step, the acceleration acting on the suspended object 16 is reduced, making it possible to prevent the suspension of the suspended object 16 from swaying smoothly and reliably.

[0031] Furthermore, the sway-preventing treatment for the suspended object 16 shown in Figure 6 is such that the second control moves the suspension position (17a) in the opposite direction to the first control, thus reducing the distance the suspension position (17a) moves.

[0032] Furthermore, as described above, in the second control of the sway-preventing process for the suspended object 16 shown in Figure 6, the timing of the movement of the suspension position (17a1) is when the suspended object 16 has moved from the second reference position on the second reference line VL2 to the maximum amplitude position (at a distance m2) at the suspension position (17a1) at the end of the first control. Therefore, the sway-preventing process for the suspended object 16 according to this embodiment can be expected to have a large sway-preventing effect.

[0033] In addition, although the sway-preventing treatment for the suspended object 16 shown in Figure 6 is performed in the +X direction, it is not limited to this and may also be performed in the -X direction. In this case, when the sway-preventing treatment for the suspended object 16 is performed in the -X direction, the movement of the suspension position (17a) in Figure 6(a) is performed by raising the boom 2.

[0034] Furthermore, although the sway-stopping process for the suspended object 16 shown in Figure 6 is performed in two stages, the first control and the second control, it is not limited to this, and may be performed in three or more stages, for example, if the amplitude of the suspended object 16 does not fall below a predetermined set value (see steps S8 to S11 in Figure 8). In this way, when the sway-stopping process for the suspended object 16 is performed in three or more stages, the movement distance of the suspension position (17a) is determined to be the optimal value according to the number of times the sway-stopping process is performed. Note that this first example of the sway-stopping process illustrates a case where it is performed based on the amplitude of the suspended object 16, but it is not limited to this, and may be performed based on the number of times the sway-stopping process is performed.

[0035] Furthermore, the sway-stopping process for the suspended object 16 is preferably performed in an even number of steps to make it easier to cancel out the forces acting on the suspension position (17a). For example, if the sway-stopping process for the suspended object 16 consists of a first control and a second control as one set, then multiple sets of the first and second control may be performed. In this way, when multiple sets of the first and second control, which have opposite control directions, are performed, the distance traveled by the boom 2 at the start and end of the sway-stopping process is reduced, so the position is less likely to shift before and after the start. In addition, there is no need to secure a large space when the crane is not in operation, making it particularly effective when the crane is not in operation. Note that, after performing one set of the first and second control, if the amplitude of the suspended object 16 becomes less than or equal to the set value at the end of the first control, the sway-stopping process for the suspended object 16 may be terminated without performing the second control.

[0036] Furthermore, the sway-preventing process for the suspended object 16 may be performed such that either the first control or the second control is executed multiple times.

[0037] Furthermore, in this embodiment, the sway suppression of the suspended object 16 is performed automatically by the control unit 23, etc., using the sway suppression processing program 31, but it is not limited to this, and the operator may manually operate the operation unit 25 to bring the suspension position (17a) closer to the suspended object 16. In the case of such manual operation of the crane 1 by the operator, for example, the display unit 26 will give instructions to the operator, and the operator will perform the actual operation. Note that in Figure 6(b), the suspension position (17a2) and the suspended object 16 do not perfectly coincide, and there may be a misalignment between the suspension position (17a2) and the suspended object 16.

[0038] (Second example of vibration damping treatment) Figure 7(a) is a plan view showing a second example of the sway-preventing treatment for the suspended object 16, and shows the case where the maximum amplitude direction of the suspended object 16 is along the Y-axis direction, vibration pattern II. Also, Figure 7(a) shows the sway-preventing treatment for the suspended object 16 when no obstacle (32) is detected by the obstacle detection program 31b. Note that the explanation of this second example of the sway-preventing treatment for the suspended object 16 will omit explanations that are common to the explanation of the first example as appropriate.

[0039] As shown in Figure 7(a), the boom operation control program 31c focuses on the fact that vibration of the suspended object 16 is suppressed when the center 17a of the point sheave 17 (which is the pivot point for the amplitude of the suspended object 16 and the suspension position of the suspended object 16 to the boom 2) is brought close to the maximum amplitude position of the suspended object 16, and calculates the slewing angle of the boom 2. Furthermore, this second example performs a sway suppression process for the suspended object in the +Y axis direction, and the first and second control are performed in the same way as in the first example.

[0040] In this second example, the movement of the suspension position (17a) is performed by the rotation of the boom 2, and the boom operation control program 31c calculates the rotation angle of the boom 2 based on the calculation results of the suspended object position measurement program 31a (maximum amplitude, direction of swing, period of swing of the suspended object 16), etc. Then, the control unit 23 operates the rotation device 30 based on the calculation results of the boom operation control program 31c, and rotates the upper rotation body 6 and the boom 2.

[0041] In this second example, as in the first example, the suspension of the suspended object 16 can be prevented from swaying. In the second example, the suspension of the suspended object 16 is performed in the +Y axis direction, but this is not the only option; the suspension of the suspended object 16 can also be performed in the -Y axis direction. Furthermore, in this second example, when the boom 2 is rotated, it enters a neutral state (rotation neutral free state) between the first control and the second control, as in manual operation. In this rotation neutral free state, the boom 2 rotates due to the inertia of the upper rotating body 6 (oil circulates according to the rotation due to the inertia of the hydraulic motor for rotation). Furthermore, in the neutral state of this second example, when the boom 2 rotates due to the inertia of the upper slewing body 6, the rotation of the boom 2 may be braked. For example, a separate hydraulic brake may be provided for the hydraulic motor used for rotation, and the rotation may be braked by this hydraulic brake. In this case, the rotation speed of the boom 2 will be further reduced by the hydraulic brake.

[0042] (Third example of vibration damping treatment) Figure 7(b) is a plan view showing a third example of the sway-damping treatment for the suspended object 16, and shows the case of vibration pattern III where the direction of the maximum amplitude of the suspended object 16 is tilted counterclockwise by θ with respect to the X-axis direction. Also, Figure 7(b) shows the sway-damping treatment for the suspended object 16 when no obstacle (32) is detected by the obstacle detection program 31b. Note that the explanation of this third example of the sway-damping treatment for the suspended object 16 will omit explanations that are common to the explanation of the first example as appropriate.

[0043] As shown in Figure 7(b), the boom operation control program 31c focuses on the fact that vibration of the suspended object 16 is suppressed when the center 17a of the point sheave 17 (which is the pivot point for the amplitude of the suspended object 16 and the suspension position of the suspended object 16 to the boom 2) is brought close to the position of the maximum amplitude of the suspended object 16, and calculates the slewing angle and luffing angle of the boom 2. Furthermore, in this third example, swing suppression processing of the suspended object is performed in the first quadrant, and the first and second controls are performed in the same way as in the first example.

[0044] In this third example, the movement of the suspension position (17a) is performed by the rotation and luffing of the boom 2. The boom operation control program 31c calculates the rotation angle and luffing angle of the boom 2 based on the calculation results of the suspended object position measurement program 31a (maximum amplitude, direction of swing, and period of swing of the suspended object 16). The control unit 23 then operates the rotation device 30 based on the calculation results of the boom operation control program 31c to rotate the upper rotation body 6 and the boom 2, and also operates the luffing winch 10 based on the calculation results of the boom operation control program 31c to luff the boom 2.

[0045] This third example, like the first example, can be used to prevent the suspended object from swaying. In the third example, the suspension of the suspended object 16 is performed in the first quadrant, but this is not the only example; the suspension of the suspended object 16 can also be performed in the third quadrant. Furthermore, the third example can be applied to vibration pattern IV, where the direction of the maximum amplitude of the suspended object 16 is tilted clockwise by θ with respect to the X-axis direction.

[0046] (Procedure for preventing vibration) Figure 8 is a flowchart showing the process of preventing swaying of the suspended object 16 in the crane 1 according to this embodiment.

[0047] In this embodiment, the sway-preventing process for the suspended object 16 is performed, for example, by the control unit 23 reading and deploying the sway-preventing process program 31 from the storage unit 28 based on operator input. Alternatively, the sway-preventing program 31 may be read and deployed after other automatic operations, without operator input.

[0048] First, the maximum amplitude, direction of swing, and period of swing of the suspended object 16 are calculated by the suspended object position measurement program 31a (step S1). Image data acquired by camera 4 is used to calculate the maximum amplitude, etc., of the suspended object 16.

[0049] Next, the obstacle detection program 31b identifies any obstacles that could potentially collide with the suspended object 16 (step S2). This obstacle identification by the obstacle detection program 31b is performed using image data acquired by the camera 4.

[0050] If the obstacle detection program 31b determines that an obstacle is present, the obstacle detection program 31b determines the direction of the anti-sway mechanism to avoid collision with the obstacle (step S3).

[0051] If the obstacle detection program 31b determines that there are no obstacles, the suspension process for the suspended object 16 (steps S4 to S9) is performed in a predetermined arbitrarily set suspension direction (see the first to third examples of suspension process for the suspended object). If the obstacle detection program 31b determines that there are obstacles, the suspension process for the suspended object 16 is performed in the suspension direction determined in step 3 (steps S4 to S9). If an obstacle is detected by the obstacle detection program 31b after the suspension process has started (for example, after the first control is completed), the second control in the direction in which the obstacle was detected is not performed. In addition, in the first control, the first displacement position 16a1 is located on the opposite side of the first reference position with respect to an object (obstacle) among the objects detected by the camera (detection unit) 4 that may come into contact with the suspended object 16. Thus, the anti-sway treatment of the suspended object 16 in this embodiment allows the suspended object 16 to move in a way that avoids obstacles, thereby preventing collisions between the suspended object 16 and obstacles, and enabling safer work operations.

[0052] The sway-preventing process first detects the first reference position and the first misaligned position 16a1 of the suspended object 16 (step S4). This detection of the first reference position and the first misaligned position 16a1 of the suspended object 16 is performed, for example, by a camera 4 or an operator. At this point, it is possible to determine whether or not there is an obstacle.

[0053] Next, the boom 2 is moved from the first reference position toward the first misaligned position 16a1 (step S5).

[0054] Next, the camera 4 and / or operator detect that the suspension position 17a (reference position) of boom 2 is located on the opposite side of the first misaligned position 16a1 from the suspension position 17a1 (first reference position) of boom 2 (step S6). At this point, it is possible to determine whether or not there is an obstacle.

[0055] Next, the boom 2 is moved from the second reference position toward the second misaligned position 16a2 (step S7).

[0056] Next, the amplitude of the suspended load 14 (suspended object 16) is detected by the camera 4 or the operator (step S8).

[0057] Next, it is determined in step S9 whether the amplitude of the suspended load 14 (suspended object 16) detected in step S8 is less than or equal to a preset value (set value). If it is determined that the amplitude is less than or equal to the set value, the sway suppression process (first control and second control) of the suspended object 16 is terminated. As a result, the sway of the suspended object 16 is reliably suppressed. The sway suppression process may also be stopped after a predetermined number of processing times (multiple times). Alternatively, the sway suppression process may be stopped when the amplitude of the suspended object 16 is less than or equal to a predetermined set value and the total number of sway suppression processing times for the first and second controls combined is an even number. (In this case, in step S9 of Figure 9, if NO, the system returns to step S4 via the dotted line.) When conditions are set in this way, the distance traveled before and after the sway suppression process can be reduced, and sway can be suppressed more reliably.

[0058] On the other hand, if it is determined that the amplitude exceeds the set value (step S9), the Nth reference position and the Nth misaligned position are detected (step S10), the boom 2 is moved from the Nth reference position toward the Nth misaligned position (step S11), the amplitude of the suspended load 14 (suspended object 16) is detected (step S8), and the sway-stopping process in steps S10, S11, S8, and S9 is repeated until the amplitude falls below the set value (step S9). In this embodiment, N is a value of 3 or more, and increases by 1 each time the sway-stopping process is repeated.

[0059] The above embodiment shows an example of a vibration suppression process that controls the amplitude of the suspended object 16 to be less than or equal to a set value, but it is not limited to this, and the vibration suppression process may also be controlled by the number of times the vibration suppression process is performed (a number of times arbitrarily set in advance). For example, the number of times the vibration suppression process is performed may be two, as shown in steps S4 to S7 of Figures 6, 7, and 8.

[0060] (Effects of this embodiment) The crane 1 of this embodiment can effectively suppress the swing of the suspended object 16 when the transport operation of the suspended object 16 is stopped.

[0061] Furthermore, since the crane 1 of this embodiment is configured to prevent the swaying of the suspended object 16 through multiple sway-preventing processes, even if the suspended object 16 consists of a hook 12 and a suspended load 14, the acceleration acting on the hook 12 and the suspended load 14 can be reduced compared to the case where the swaying of the suspended object 16 is prevented by performing a single sway-preventing process, thereby preventing double vibration from occurring between the hook 12 and the suspended load 14.

[0062] (Other embodiments) The crane 1 according to the present invention may have the installation angle of the camera 4 variably set by a movable mechanism (not shown) such as a servo motor. In the crane 1 of this embodiment, the state of the suspended load was detected by the camera 4 and a sway suppression process was performed. However, the crane 1 may also be operated by an operator who monitors the state of the suspended load and performs the first and second controls described above. In this case as well, when the transport operation of the suspended object 16 is stopped, the sway of the suspended object 16 can be effectively suppressed.

[0063] Furthermore, the present invention is not particularly limited to the type of crane, and may include all types of cranes, including mobile cranes such as crawler cranes, wheel cranes, and truck cranes, as well as port cranes, overhead cranes, gantry cranes, unloaders, and fixed cranes. Furthermore, the present invention also includes cranes that are excavators having a boom and an arm, with a rope suspended from the arm and a hook attached to the rope. Furthermore, details shown in the above embodiments can be modified as appropriate without departing from the spirit of the invention. [Explanation of symbols]

[0064] 1 Crane 2 Boom 16 Hanging objects 16a1 First displacement position 16a2 Second displacement position

Claims

1. A crane having a boom, a suspended object suspended from the boom, and a detection unit for detecting objects around the suspended object, In a planar coordinate system viewed vertically downward from above the crane, if the position where the suspended object is suspended from the boom without swaying is defined as the reference position of the suspended object, When the suspended object is at a first misaligned position that is shifted from a first reference position, a first control is performed to move the boom in the planar coordinate system closer to the first misaligned position, When the suspended object is at a second misaligned position which is a reference position after the first control, the second control is performed to move the boom in the planar coordinate system closer to the second misaligned position, Perform The first control is a crane in which, with respect to an object among the objects detected by the detection unit that has the potential to come into contact with the suspended object, the first displacement position is located on the opposite side of the first reference position.

2. The crane according to claim 1, wherein the second control is performed after the suspended object is positioned on the opposite side of the second reference position from the first misaligned position.

3. The crane according to claim 2, wherein the second control is performed when the suspended object is at a second misaligned position opposite to the first misaligned position, with respect to the second reference position.

4. The crane according to claim 3, wherein, when the first control and the second control constitute one set, the first control and the second control are repeated multiple times.

5. The crane according to any one of claims 1 to 4, wherein the first control and the second control are terminated when the amplitude of the suspended object falls below a predetermined value.

6. The crane according to any one of claims 1 to 4, wherein the start timing of the first control or the second control is when the suspended object is moving from the reference position to the maximum amplitude position.

7. The crane according to any one of claims 1 to 4, wherein the first control is initiated when the boom is not being rotated or raised and when the suspended object is not being hoisted up or down.

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