Crane

Abstract

To provide a crane with a configuration useful for controlling the sway of suspended loads.SOLUTION: A crane is equipped with a boom, a camera that is supported by the boom and captures an image of an area including the suspended load, an attitude sensor that detects the attitude of the camera, and an output unit that outputs a result of determination as to whether or not anti-sway operation of the suspended load should be performed based on the image data acquired by the camera and the detection information of the attitude sensor.SELECTED DRAWING: Figure 5

Description

Technical Field

[0001] The present invention relates to a crane.

Background Art

[0002] Patent Document 1 describes a crane in which a sensor unit is attached to the tip portion of a boom via a gimbal. The sensor unit is equipped with a camera and an inertial measurement device.

Prior Art Document

Patent Document

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the crane of Patent Document 1, when the boom is twisted or the like, the posture of the camera may change or vibrate. It is not possible to accurately detect what kind of swing is occurring in the suspended load from the image of the suspended load captured by the camera. Therefore, the anti-sway control may not be performed well.

[0005] An object of the present invention is to provide a crane capable of more accurately performing anti-sway control of a suspended load.

Means for Solving the Problems

[0006] A crane according to one aspect of the present invention includes: a boom, a camera supported by the boom and photographing a region including a suspended load, an attitude sensor for detecting the attitude of the camera, an output unit that outputs a determination result as to whether or not anti-sway operation of the suspended load should be performed based on the video data acquired by the camera and the detection information of the attitude sensor. comprises.

[0007] Another aspect of the crane according to the present invention a boom, a camera supported by the boom and photographing an area including a suspended load, an attitude sensor for detecting the attitude of the camera, a control unit that executes anti-sway operation of the suspended load based on the video data acquired by the camera and the detection information of the attitude sensor, comprises.

[0008] Another aspect of the crane according to the present invention a boom, a camera supported by the boom and photographing an area including a suspended load, an attitude sensor for detecting the attitude of the camera, a display unit that outputs the video photographed by the camera, comprises, the display unit corrects a reference point of the video based on information detected by the attitude sensor, the reference point is a point associated with the sway center of the suspended load.

Advantages of the Invention

[0009] According to the present invention, an effect of being able to perform anti-sway control of a suspended load more accurately can be obtained.

Brief Description of the Drawings

[0010]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Embodiments for Carrying Out the Invention

[0011] Hereinafter, each embodiment of the present invention will be described in detail with reference to the drawings.

[0012] (Embodiment 1) FIG. 1 is a diagram showing a crane according to Embodiment 1 of the present invention. FIG. 2 is a side view of the camera unit portion of FIG. 1 enlarged.

[0013] The crane 1 of Embodiment 1 is a mobile crane such as a crawler crane, for example. The crane 1 includes a self-propelled lower traveling body 2, an upper slewing body 3 rotatably supported by the lower traveling body 2, a boom 4 attached to the upper slewing body 3 so as to be able to rise and fall, a mast 5 supporting the boom 4, and a counterweight 6 mounted on the rear of the upper slewing body 3. The upper slewing body 3 is provided with a winch 7 for winding and unwinding the wire rope W1 and a cab 8 where the driver drives. A sling 9 engaged with the suspended load is suspended from the tip of the boom 4 via the wire rope W1. The driver is an example of an operator according to the present invention.

[0014] At the tip of the boom 4, a camera 21 for photographing the area where the suspended load supported by the boom 4 is included, and an attitude sensor 22 for detecting the attitude of the camera 21 are provided. The tip means the tip side portion among the three equal parts of the boom 4 in the longitudinal direction. The camera 21 and the attitude sensor 22 are rotatably fixed to the boom 4. The area where the suspended load is included means the area where the suspension tool 9 is included when the suspended load is not being suspended. Note that the camera 21 may be fixed to the boom 4 in a non-rotatable state.

[0015] As shown in FIG. 2, the camera 21 and the attitude sensor 22 are attached to a support base 20A such as a housing or a bracket and are unitized. That is, the camera 21 and the attitude sensor 22 are attached to one support base 20A in a state where they do not relatively displace. Therefore, the attitude of the attitude sensor 22 corresponds to the attitude of the camera 21, and the attitude detected by the attitude sensor 22 represents the attitude of the camera 21.

[0016] The support base 20A is attached to the boom 4 via a support frame 20B that rotatably supports the support base 20A. The support frame 20B is rotatable about one rotation axis, and the rotation axis is parallel to the central axis of the up-and-down movement of the boom 4. With such a configuration, even when the boom 4 changes its up-and-down angle from a state close to horizontal to a state close to vertical, the support base 20A can be directed vertically downward from the tip of the boom 4 by its own weight. The rotatable configuration of the support frame 20B may be provided with a notch mechanism such that the position is semi-fixed at a plurality of rotation angles. The notch mechanism imparts a fixing action to the extent that it does not prevent the rotation of the support base 20A due to its own weight including the supported configuration. With this configuration, the support base 20A can be rotated as the boom 4 undulates, while it is possible to reduce the sway of the support base 20A with respect to the support frame 20B due to weak wind or the like.

[0017] Note that the support base 20A is not limited to a configuration that rotates with respect to the support frame 20B due to its own weight. For example, it may be a configuration in which the angle of view of the camera 21 is actively rotated by an actuator so as to face the direction of the suspended load. Further, the rotation mechanism of the support base 20A is not limited to a mechanism that rotates about a single axis. For example, various mechanisms such as a two-axis rotation mechanism having two rotation axes, a mechanism that can be rotated at various angles via a universal joint, etc. may be adopted.

[0018] The attitude sensor 22 is a sensor for detecting the attitude of the camera 21, and is, for example, an IMU (Inertial Measurement Unit). The attitude refers to the inclination angles in the three-axis directions of the camera 21 (for example, roll angle, pitch angle, yaw angle). The three axes mean three axes that are orthogonal to each other. The attitude sensor 22 can measure the inclination angles in the three-axis directions (for example, roll angle, pitch angle, yaw angle) from the reference attitude when the attitude at an arbitrary reference time point is taken as the reference attitude by detecting the acceleration in the three-axis directions, the direction of gravity (vertical direction) at rest, and the angular velocity in the three-dimensional directions. Note that the attitude sensor 22 is not limited to this, and other sensors may be used as long as the attitude can be detected. For example, the attitude sensor 22 may be a sensor that further includes a geomagnetic sensor, or a sensor that only includes an inclination angle sensor.

[0019] With the above configuration of the attitude sensor 22, for example, taking the state where the boom 4 is at a predetermined angle as the reference attitude, by measuring the tilt angles in three axial directions with the attitude sensor 22, it is possible to determine how the position and angle of the boom 4 change, and how the support base 20A changes in orientation with respect to the support frame 20B, and thus obtain the attitude of the attitude sensor 22. Then, by comparing the attitude of the boom 4 with the attitude of the attitude sensor 22, it becomes possible to obtain the tilt angle of the attitude sensor 22 relative to the boom 4. The attitude of the boom 4 can be obtained from the value of the elevation angle measuring device 25 provided in the elevation mechanism of the boom 4 and the value of the turning angle measuring device 26 provided in the turning mechanism of the upper slewing body 3. Note that the elevation angle measuring device 25 and the turning angle measuring device 26 are not limited to this as long as their respective angles can be measured. Instead, an attitude sensor similar to the attitude sensor 22 may be fixed to the boom 4, and the angle of the boom 4 may be obtained based on the output of the attitude sensor.

[0020] The attitude sensor 22 is arranged on the same straight line as the optical axis A21 (see FIG. 2) of the camera 21. The extension line of the optical axis A21 is shown by a thick dashed line. With such a configuration, when calculating the tilt angle of the camera 21 or the tilt angle of the camera 21 with respect to the boom 4 from the output of the attitude sensor 22, the calculation becomes easier. In particular, since the change in error is small regardless of the attitude, the error in the tilt angle is reduced. The attitude sensor 22 is arranged on the same straight line as the above optical axis A21 and on the side opposite to the shooting direction of the camera 21. With such a configuration, the attitude sensor 22 can be arranged on the same straight line as the optical axis A21 of the camera 21 without obstructing the shooting of the camera 21.

[0021] FIG. 3 is a block diagram showing the control configuration in the crane of FIG. 1. The crane 1 includes a control unit 31 that performs control for driving assistance, an operation unit 32 for an operator to perform driving operations, an output unit 33 that notifies the operator by display, voice, or both, a display unit 34 that displays a suspended load, and a mode operation unit 35 that can switch the operation mode to the anti-sway mode. The operation unit 32, the output unit 33, the display unit 34, and the mode operation unit 35 are arranged in the cab 8. However, in the case where the crane 1 is remotely controlled, they may be arranged in a remote control room away from the crane 1. Further, the output unit 33 and the display unit 34 may be provided outside the cab 8.

[0022] The control unit 31 is a computer that operates according to a control program. Outputs of the above-described camera 21, attitude sensor 22, measuring instruments 25 and 26 that measure the turning angle and the hoisting angle of the boom 4, and measuring instrument 27 that measures the payout amount of the wire rope W1 are sent to the control unit 31. The wire rope W1 suspends the suspended load, and the suspension length of the suspended load can be calculated from the payout amount thereof. The operation signal of the mode operation unit 35, the video data of the camera 21, and the detection information of the attitude sensor 22 are sent to the control unit 31. The control unit 31 can output notification information from the output unit 33 and perform display output of video and images via the display unit 34 by sending display data to the display unit 34. Further, the control unit 31 can turn the boom 4 and cause it to rise and fall, and raise and lower the suspended load by outputting a command to the drive mechanism of the crane 1.

[0023] Based on the detection information of the attitude sensor 22 (i.e., the attitude information of the camera 21), the turning angle of the boom 4, the hoisting angle of the boom 4, and the payout amount of the wire rope W1 that suspends the load, the control unit 31 can accurately calculate at which position within the viewing angle of the camera 21 the reference position of the suspended load where the load is located when there is no sway of the load is. Further, from the above information, the control unit 31 can accurately calculate which direction within the viewing angle of the camera 21 is the turning direction (i.e., the direction in which the suspended load moves due to turning) and which direction is the hoisting direction (i.e., the direction in which the suspended load moves due to hoisting).

[0024] The control unit 31 can further switch the operation mode of the crane 1. The operation modes include a normal mode in which an operator operates and a vibration damping mode in which the swing of the suspended load is reduced by automatic steering.

[0025] <Vibration damping operation by automatic steering> FIG. 4 is a flowchart showing the control process of the vibration damping operation by automatic steering executed by the control unit. The control process is started by the control unit 31 when shifting to the vibration damping mode. Note that the vibration damping operation includes not only completely stopping the swing but also suppressing the swing.

[0026] When shifting to the vibration damping mode, the control unit 31 calculates the attitude of the camera 21 from the detection information of the attitude sensor 22 (step S1). Further, the control unit 31 acquires the measurement information of the turning angle and the hoisting angle of the boom 4 and the information of the payout amount of the wire rope W1 (step S2). Then, based on the information in steps S1 and S2, the control unit 31 calculates which position in the viewing angle of the camera 21 is the swing center position of the suspended load (the position of the center of the suspended load when there is no swing of the suspended load) (step S3). Further, the control unit 31 calculates the turning direction and the hoisting direction of the boom 4 in the viewing angle of the camera 21 based on the information in steps S1 and S2 (step S4).

[0027] Subsequently, the control unit 31 performs image analysis based on the video data of the camera 21 to obtain the swing direction and the swing width of the suspended load (step S5), and calculates the movement of the boom 4 to reduce the swing (step S6). The movement of the boom 4 is, for example, a movement of displacing the boom 4 a short distance in the same direction as the swing of the suspended load, but various movements may be applied as long as the swing of the suspended load can be reduced. The image analysis in step S5 shall include calculations by a machine-learned artificial intelligence.

[0028] The control unit 31 automatically executes the slewing operation and the hoisting and lowering operation (or the telescoping operation if the boom 4 is telescopic) of the boom 4 by automatic control so that the movement calculated in step S6 occurs (step S7). This operation corresponds to the anti-sway operation of the suspended load by automatic control. When the automatic control is completed, the control unit 31 ends the anti-sway operation process. The above anti-sway operation is an operation in which the amount of movement of the boom 4 is determined based on the video data and the output (detection information) of the attitude sensor 22.

[0029] According to the above operation process, the control unit 31 can accurately calculate in which direction and by how much the suspended load is swaying based on the detection information of the attitude sensor 22 indicating the attitude of the camera 21 and the video data of the camera 21. Then, based on the calculation result, the control unit 31 performs an operation to displace the boom 4 in order to reduce the sway of the suspended load. Therefore, the sway of the suspended load can be efficiently reduced (for example, in a short time and with a small displacement of the boom 4).

[0030] Note that the anti-sway operation process by automatic control by the control unit 31 is not limited to being started based on the operation of the operation mode by the operator. For example, the above operation process may be automatically executed during the following operations. That is, during the period when the operator is operating to transport the suspended load, for example, the control unit 31 may automatically start the anti-sway operation process near the transport end point. And also in such an anti-sway operation process, the control unit 31 calculates in which direction and by how much the suspended load is swaying based on the accurate measurement result of the attitude of the camera 21 and the video data of the camera 21, and based on the calculation result, performs an operation to displace the boom 4. Therefore, the automatic operation by the control unit 31 to reduce sway functions effectively, and efficient and stable reduction of the sway of the suspended load can be realized.

[0031] <Control Process> FIG. 5 is a flowchart showing the control process of the crane executed by the control unit. The control process starts when the control unit 31 is activated. When the control process starts, the control unit 31 calculates the arrangement relationship between the viewing angle of the camera 21 and the boom 4 and the suspended load from the detection information of the attitude sensor 22, the turning angle and the elevation angle of the boom 4, and the payout amount of the wire rope W1. Then, the control unit 31 calculates which position in the video of the camera 21 is the center of the swing of the suspended load (step S11). Further, in step S11, the control unit 31 also calculates which directions the turning direction and the elevation direction of the boom 4 are. Here, since the calculation is performed based on the attitude information representing the attitude of the camera 21, even if the boom 4 is twisted or vibrating, the calculation result will be more accurate.

[0032] Subsequently, the control unit 31 obtains the position and displacement speed of the suspended load by analyzing the video data of the camera 21, and calculates the swing amplitude of the suspended load by performing calculations in combination with the calculation results of step S11 (step S12). Here, since the center position of the swing of the suspended load is accurately obtained by the process of step S11, the swing amplitude can be accurately obtained. It should be noted that the above image analysis includes calculations by a machine-learned artificial intelligence.

[0033] Then, the control unit 31 determines whether the swing amplitude is equal to or greater than the threshold value (step S13). As a result, if it is NO, the control unit 31 outputs, via the output unit 33, notification information indicating that the anti-swing operation of the load is unnecessary (step S14). On the other hand, if the result of the determination in step S12 is YES, the control unit 31 outputs, via the output unit 33, information indicating that the anti-swing operation of the load should be performed (step S15). The outputs in steps S14 and S15 may adopt information display outputs (such as character display, color display such as warning color and standard color, presence or absence of a predetermined display mode of a warning light, etc.), or voice output from a speaker may also be adopted.

[0034] Based on the notification outputs in steps S14 and S15, the driver can determine whether to perform the anti-sway operation of the suspended load. For example, when the information indicating that it should be performed is output, the driver can perform the anti-sway operation of the suspended load and reduce the sway of the suspended load. On the other hand, when the information indicating that it is unnecessary is output, the driver can continue the conveyance operation of the suspended load without performing the anti-sway operation. Therefore, the driver can realize an efficient conveyance process of the suspended load.

[0035] Note that in the above example, a configuration is shown in which the control unit 31 determines whether to perform the anti-sway operation based on the sway amplitude of the suspended load. However, the determination of whether to perform the anti-sway operation may be made in consideration of various information such as the sway direction of the suspended load (such as the heaving direction or the turning direction), the relative positional relationship between the structure located around and the suspended load (such as whether the sway is such that the load approaches the structure), and the load factor of the suspended load (such as how close the current load is to the limit load).

[0036] Subsequently, the control unit 31 determines whether a shift command to the anti-sway mode is input via the mode operation unit 35 (step S16). And when there is a shift command, the control unit 31 makes the same determination as in step S13 (step S17), and when it is determined that the anti-sway operation is unnecessary, cancels the shift to the anti-sway mode (step S18). At this time, the control unit 31 may notify the driver by display or voice that the shift to the anti-sway mode has been canceled. According to the process of step S18, an opportunity for reconsideration can be given when the driver tries to perform unnecessary anti-sway control. On the other hand, when it is determined that the anti-sway control should be performed, the control unit 31 executes the anti-sway operation by automatic steering (step S19).

[0037] And when there is no shift command to the anti-sway mode, when the automatic steering is canceled, or when the anti-sway operation by automatic steering is completed, the control unit 31 repeats the process from step S11 again.

[0038] According to the above control process, the driver can determine whether to perform anti-sway operation based on the accurate measurement result of the sway of the suspended load, and by this determination, the necessary anti-sway operation can be realized. Therefore, even a driver with low proficiency can operate the crane 1 more efficiently and stably.

[0039] <Display control process> Figure 6 is a flowchart showing the display control process executed by the control unit. The display control process is repeatedly executed during the driving of the crane 1. When the display control process is started, the control unit 31 calculates the arrangement relationship between the viewing angle of the camera 21 and the boom 4 and the suspended load from the detection information of the attitude sensor 22, the turning angle and the elevation angle of the boom 4, and the payout amount of the wire rope W1. Then, the control unit 31 corrects the reference point of the video from the above arrangement relationship (step S21).

[0040] The reference point is a point associated with the sway center of the suspended load, specifically, the center point of the sway of the suspended load. The center point of the sway is the point when the suspended load is vertically lowered from the tip of the boom 4. Note that the reference point is not limited to the center point of the sway. For example, it may be the origin "X = 0, Y = 0" when the center point of the sway is set to a predetermined value "X = X0, Y = Y0" (where X is the X-axis coordinate in the video and Y is the Y-axis coordinate in the video). That is, the reference point only needs to be a point associated with the sway center point so that the sway center point can be known from the reference point. The correction of the reference point includes corrections on at least two axes, the X-axis and the Y-axis.

[0041] In step S21, in order to correct the reference point, the control unit 31 calculates, from the angular field of view of the camera 21 and the arrangement relationship between the boom 4 and the suspended load, which position in the image of the camera 21 is the center of the swing of the suspended load. Further, in step S21, the control unit 31 also calculates which directions in the image are the turning direction and the pitching direction of the boom 4. Then, the control unit corrects the reference point by adding the difference between the center of swing of the suspended load in the standard state and the calculated center of swing to the reference point at the standard time. Here, the standard state may be determined in advance as the standard state when the arrangement relationship between the boom, the camera, and the suspended load is in an arbitrary relationship.

[0042] In step S21, since the calculation is performed based on the attitude information representing the attitude of the camera 21, even if the boom 4 is twisted or the like, the exact arrangement relationship between the boom 4 and the camera 21 can be calculated, and thus the calculation result of the reference point is also accurate.

[0043] Subsequently, the control unit 31 inserts into the video data of the camera 21 an image (intersection points A0, A1, etc., see FIG. 7) indicating the center of swing of the suspended load as the reference point, an image (scale lines Lx0, Lx1, etc., see FIG. 7) indicating the turning direction (the direction in which the suspended load moves due to the turning of the upper swing body 3), and an image (scale lines Ly0, Ly1, etc., see FIG. 7) indicating the pitching direction (the direction in which the suspended load moves due to the pitching of the boom 4) (step S22). Here, the control unit 31 determines the insertion position of each image based on the calculation result of step S21. Then, the control unit outputs the video data with the images inserted to the display unit 34 (step S23).

[0044] Then, the control unit 31 repeats the processes of steps S21 to S23 at predetermined time intervals.

[0045] FIG. 7 is a diagram showing the image output from the display unit 34 by the display control process of FIG. 6. (A) is the image in the standard state, and (B) is the image when the boom 4 is twisted and the direction of the camera 21 is deviated from the standard state.

[0046] In the standard state, as shown in, for example, FIG. 7(A), an image is output to the display unit 34 in which the center of the video is the swing center (intersection point A0) of the suspended load, the horizontal direction of the video is the turning direction (scale line Lx0), and the vertical direction of the video is the heaving direction (scale line Ly0).

[0047] On the other hand, when the boom 4 is twisted or the orientation of the camera 21 is displaced, as shown in FIG. 7(B), the swing center (intersection point A1) of the suspended load is located outside the center of the video, and an image in which the turning direction (scale line Ly1) and the heaving direction (scale line Lx1) are deviated from the horizontal and vertical directions of the video is output to the display unit 34.

[0048] In any of the images, if the suspended load is swinging, the suspended load will swing around the intersection points A0 and A1 in the image. The period of swing of the suspended load is relatively long, but the image shows an image (intersection points A0, A1) indicating the swing center of the suspended load and images (scale lines Lx0, Ly0, Lx1, Ly1) indicating each direction. Therefore, the driver can quickly and accurately grasp the size and direction of the swing of the suspended load from the video without waiting for one period or half a period of the swing. Then, by performing the anti-swing operation while viewing the video, the swing of the suspended load can be accurately and efficiently reduced. If, different from the present embodiment, the intersection points A0 and A1 do not change in accordance with the swing center of the suspended load and the intersection point A0 is always located at the center of the video. In such a configuration, when the posture of the camera 21 changes due to the twist of the boom 4 or the swing of the camera 21, it is difficult for the driver to determine whether the suspended load is actually swinging. However, by displaying the reference of the swing center of the suspended load such as the intersection points A0 and A1 as in the present embodiment, the driver can easily determine whether the suspended load is actually swinging.

[0049] In the example of Fig. 7, an example of correcting the reference point of the video is shown by changing the positions of the images (intersection points A0, A1, scale lines Lx0, Ly0, Lx1, Ly1) added to the video according to the posture of the camera 21. However, a configuration may be adopted in which a part of the video acquired by the camera 21 is cut out in a frame shape and the cut-out video is output to a predetermined frame on the screen of the display unit 34. Then, the reference point of the video may be corrected by changing the part to be cut out in the above frame shape according to the posture of the camera 21. In this case, for example, the video may be cut out with a frame in which the calculated intersection point A1 is the center on the video and the calculated scale lines Lx1 and Ly1 are in the horizontal and vertical directions on the video.

[0050] As described above, according to the crane 1 of the present embodiment, it includes a camera 21 that photographs an area including a suspended load supported by the boom 4, and a posture sensor 22 that detects the posture of the camera 21. Further, according to the crane 1, an output unit 33 is provided that outputs a judgment result as to whether or not anti-sway operation of the suspended load should be performed based on the video data acquired by the camera 21 and the detection information of the posture sensor 22. In this way, based on the detection information representing the posture of the camera 21 and the judgment result based on the video data of the camera 21, for example, even when the boom 4 is twisted, the orientation of the camera 21 deviates from the standard, or the camera 21 shakes, an accurate judgment result reflecting these can be obtained. Therefore, the operator can perform the necessary anti-sway operation based on the judgment result. Thus, even an operator with low proficiency can operate the crane 1 efficiently and stably.

[0051] Furthermore, according to the crane 1 of the present embodiment, it has an anti-sway mode for performing anti-sway operation. On the other hand, according to the crane 1, even if a shift command to the anti-sway mode is input via the mode operation unit 35, the shift to the anti-sway mode is canceled when the above judgment result is negative (see step S18 in Fig. 5). Therefore, when the operator tries to perform unnecessary anti-sway control, an opportunity for reconsideration can be given. Thus, more efficient operation of the crane 1 is possible.

[0052] Furthermore, according to the crane 1 of the present embodiment, it includes a control unit 31 that executes a swing prevention operation of the suspended load based on the video data acquired by the camera 21 and the detection information of the attitude sensor 22. By the swing prevention operation based on the detection information representing the attitude of the camera 21 and the video data of the camera 21, even if the boom 4 is twisted or the direction of the camera 21 is deviated from the standard, a swing prevention operation that can effectively reduce the swing of the suspended load by reflecting these can be realized. Therefore, by the swing prevention operation by the control unit 31, the swing of the suspended load is effectively reduced, and even an operator with low proficiency can operate the crane 1 efficiently and stably.

[0053] Furthermore, according to the crane 1 of the present embodiment, based on the video data acquired by the camera 21 and the detection information of the attitude sensor 22, the reference point of the video output to the display unit 34 is corrected. The reference point is a point associated with the swing center of the suspended load. In this way, even if the boom 4 is twisted or the direction of the camera 21 is deviated from the standard, a video reflecting these can be output by the video in which the reference point is corrected based on the detection information representing the attitude of the camera 21. And by this video, the operator or worker can accurately and quickly grasp the magnitude and direction of the swing of the suspended load. Therefore, the operator or worker can make a correct judgment regarding the swing of the suspended load based on the grasp, and thereby an efficient and stable operation of the crane 1 becomes possible.

[0054] Furthermore, according to the crane 1 of the present embodiment, the correction of the reference point includes corrections in two axial directions (for example, the X-axis direction and the Y-axis direction) that intersect each other. Therefore, even in a situation where the direction of the camera 21 is displaced in two axial directions, such as when the boom 4 is twisted, it is possible to correct the reference point reflecting the situation. Therefore, even in such a situation, the driver or operator can accurately and promptly grasp the magnitude and direction of the swing of the suspended load from the image in which the reference point is corrected. Note that the above correction may include correction of the rotation direction, correction of the scale, or both in the image. By such correction, it is possible to output an image that can more accurately and promptly grasp the magnitude and direction of the swing of the suspended load.

[0055] Furthermore, according to the crane 1 of the present embodiment, the camera 21 is fixed to the boom 4. According to this configuration, it is possible to easily acquire an image that makes it easy to grasp the swing of the suspended load by the camera 21. In the present embodiment, the camera 21 is rotatably fixed to the boom 4, but the camera 21 may be fixed in a non-rotatable state.

[0056] Furthermore, according to the crane 1 of the present embodiment, the attitude sensor 22 is arranged on the same straight line as the optical axis A21 of the camera 21. Therefore, it is possible to simplify the calculation for obtaining the attitude of the camera 21 from the detection information of the attitude sensor 22.

[0057] The embodiments of the present invention have been described above. However, the present invention is not limited to the above embodiments. For example, in the above embodiments, based on the detection information of the attitude sensor and the video data, all of the control process of the anti-sway operation by automatic control, the output process of the determination result of whether to perform the anti-sway operation, and the display process of correcting the position of the sway center of the suspended load are performed by a single crane 1. However, in the crane according to the present invention, among these three processes, only any two or only one process may be performed. Even in this case, the effects of each process are achieved in the crane. Further, in the above embodiments, as an anti-sway operation for suppressing the sway of the suspended load, an example in which the boom 4 is operated so that the above sway is suppressed is shown. However, the anti-sway operation may be realized by controlling the payout and winding of the wire rope W1 or by adding such control. Further, the movement of the boom 4 for realizing the anti-sway operation may include expansion and contraction as long as the boom 4 can be raised and lowered, swiveled, and expanded and contracted. Further, in the above embodiments, the intersection of the scale lines is given as an example of the reference point of the video. However, the reference point of the video may be a dot image, or may be a point shown in a round image or an arrow image of an appropriate size. The image showing the reference point in the video may be in any form as long as the position of the reference point can be recognized.

[0058] Furthermore, in the above embodiments, a mobile crane is shown. However, as long as it has a boom for lifting a load, the present invention may be applied to any crane. That is, the crane according to the present invention is not limited to a crawler crane, and in addition to other mobile cranes such as a wheel crane, a truck crane, a rough terrain crane, and an all terrain crane, it can be applied to any crane such as a tower crane, a ceiling crane, a jib crane, a retractable crane, a stacker crane, a gantry crane, and an unloader. In addition, the details shown in the embodiments can be appropriately changed without departing from the gist of the invention.

Explanation of Reference Numerals

[0059] 1 Crane 2 Lower Traveling Body 3 Upper Slewing Body 4 booms 5 masts 6 counterweights 7 winches 8 cabs 9 slings W1 wire ropes 20A support bases 20B support frames 21 cameras A21 optical axes 22 attitude sensors 25, 26, 27 measuring instruments 31 control units 32 operation units 33 output units 34 display units 35 mode operation units

Claims

1. a boom, a camera supported by the boom and photographing an area including a suspended load, an attitude sensor for detecting the attitude of the camera, an output unit that outputs a determination result as to whether or not anti-sway operation of the suspended load should be performed based on the video data acquired by the camera and the detection information of the attitude sensor, a crane comprising the same.

2. Even if a shift command to an anti-sway mode for executing the anti-sway operation is input from an operation unit operated by an operator, if the determination result is negative, the shift to the anti-sway mode is cancelled. The crane according to claim 1.

3. a boom, a camera supported by the boom and photographing an area including a suspended load, an attitude sensor for detecting the attitude of the camera, a control unit that executes anti-sway operation of the suspended load based on the video data acquired by the camera and the detection information of the attitude sensor, a crane comprising the same.

4. The anti-sway operation according to claim 3, wherein the operation amount of the boom is determined based on the video data and the output of the attitude sensor.

5. a boom, a camera supported by the boom and photographing an area including a suspended load, an attitude sensor for detecting the attitude of the camera, a display unit that outputs the video photographed by the camera, comprising: The display unit corrects a reference point of the video based on information detected by the attitude sensor, The reference point is a point associated with the sway center of the suspended load. a crane

6. The correction of the reference point includes corrections in two axial directions intersecting each other. The crane according to claim 5.

7. The camera is fixed to the boom. The crane according to any one of claims 1 to 6.

8. The attitude sensor is arranged on the same straight line as the optical axis of the camera. The crane according to claim 7.

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