Working machinery

Abstract

This technology provides a way to sufficiently suppress the swaying of the lower end of a wire rope by controlling the movement of the wire rope. [Solution] The crane 100, which is a work machine, comprises a wire rope 82 having a lower end (boom hook 81) capable of holding a suspended load HL, and a suspension pivot 6S that suspends the wire rope 82 and is configured to be movable. The crane 100 moves the lower end of the wire rope 82 horizontally from a set first position to a second position. At this time, the crane 100 controls the suspension pivot 6S to precede the position of the lower end of the wire rope 82, so that the lower end of the wire rope 82 follows, and continues this state from the first position to a position close to the second position.

Description

Technical Field

[0001] The present disclosure relates to a working machine.

Background Art

[0002] In recent years, in a crane which is a working machine, a technology for automatically controlling a suspended load suspended by a wire rope along a target trajectory has been developed. However, since the suspended load may sway during transportation in the crane, there is a possibility that the suspended load cannot be transported stably. For this reason, a technology capable of performing automatic control while suppressing the sway of the suspended load is desired.

[0003] For example, Patent Document 1 discloses a technique of combining a plurality of straight paths when transporting a suspended load, or combining a straight path and an arc path so as to pass on the arc when the set straight path passes inside an arc that is the minimum value of the working radius of the crane.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, in the technique of Patent Document 1 described above, for example, when there are obstacles or the like, a complex path is formed, and the number of times of switching between a straight line and an arc increases. As a result, the suspended load (the lower end of the wire rope) suspended by the wire rope is likely to sway when switching between linear motion and circular motion. That is, simply combining a straight path and an arc path in the target trajectory and moving along the trajectory cannot sufficiently suppress the sway. For this reason, in the movement control of the wire rope, a technology capable of more sufficiently suppressing the sway of the suspended load is desired.

[0006] This disclosure provides a technology that can sufficiently suppress the swaying of the lower end of a wire rope by controlling the movement of the wire rope. [Means for solving the problem]

[0007] According to one aspect of the present disclosure, a work machine is provided comprising a wire rope having a lower end capable of holding a suspended load, and a movable suspension pivot for suspending the wire rope, wherein when the lower end of the wire rope is moved horizontally from a set first position to a second position, the suspension pivot is set to precede the lower end of the wire rope, and this state is maintained from the first position to a position close to the second position. [Effects of the Invention]

[0008] According to one embodiment, the swaying of the lower end of the wire rope can be sufficiently suppressed by controlling the movement of the wire rope. [Brief explanation of the drawing]

[0009] [Figure 1] This is a side view showing an example of a crane according to the embodiment. [Figure 2] This is a block diagram schematically showing an example of the configuration of a crane according to the embodiment. [Figure 3] This is a plan view showing the movement of the crane's suspension pivot point from its starting position to its target position. [Figure 4] This flowchart shows an example of a processing procedure for registering a target position in the simplified operation mode of the controller according to the embodiment. [Figure 5] This diagram illustrates the screen of the simplified operation mode displayed by the display control unit. [Figure 6] This flowchart illustrates the process by which the controller controls the movement of the boom in simplified operation mode. [Figure 7] This is a plan view illustrating the target trajectory from the starting position to the target position TP in the presence of obstacles. [Figure 8] Figures 8(A) to 8(C) are the first to third explanatory diagrams showing the relationship between the position of the suspension support point and the position of the suspended load in sway suppression control. [Figure 9] This is an explanatory diagram showing the relationship between the crane's slewing axis and luffing axis and the various parameters of the crane. [Figure 10] This figure shows the change in the inclination angle over time as the suspension support point moves. [Figure 11] Figures 11(A) to 11(F) are the first to sixth operation diagrams showing the operation of the suspension support point 6S and the behavior of the suspended load HL during stop control. [Figure 12] This diagram shows the action taken to suppress the leading of the suspended load when the suspended load moves ahead of the suspension point. [Figure 13] This graph shows the changes in the tilt angle of the suspended load, the change in the slewing command value, and the change in slewing speed when follow-up adjustment processing is performed in sway suppression control. [Figure 14] This is a schematic diagram showing an example configuration of a remote control system for a crane, based on a modified example. [Modes for carrying out the invention]

[0010] Hereinafter, embodiments for carrying out this disclosure will be described with reference to the drawings. In each drawing, the same reference numerals are used for the same components, and redundant descriptions may be omitted. The embodiments described below are illustrative and not limiting to the invention, and not all features or combinations thereof described in the embodiments are necessarily essential to the invention.

[0011] <Overall configuration of Crane 100> As an example of a work machine according to the embodiment of this disclosure, a mobile crane 100 shown in Figure 1 will be described. Figure 1 is a side view showing an example of the crane 100 according to the embodiment. In the following, the front-rear direction, left-right direction, and up-down direction of the crane 100 will be described along the front-rear direction, left-right direction, and up-down direction as seen from the perspective of the person riding in the crane 100 (hereinafter also referred to as the operator).

[0012] The crane 100 according to the embodiment is a so-called movable crawler crane. This crane 100 includes a self-propelled crawler-type lower traveling body 1, an upper slewing body 3 mounted on the lower traveling body 1 so as to be slewing, and an attachment AT attached to the front side of the upper slewing body 3 so as to be able to rise and fall.

[0013] The lower traveling body 1 includes, for example, a pair of left and right crawlers 1L and 1R. The lower traveling body 1 drives the crawlers with a left traveling hydraulic motor 1ML and a right traveling hydraulic motor 1MR (see FIG. 2) respectively to drive the crane 100 to travel.

[0014] The upper slewing body 3 slews with respect to the lower traveling body 1 when a slewing mechanism 2 is hydraulically driven by a slewing hydraulic motor 2M (see FIG. 2).

[0015] The upper slewing body 3 has a cab 4 where an operator sits to operate the crane 100 at an adjacent position on the right side of the attachment AT. Further, the upper slewing body 3 has a counterweight 5 for taking the weight balance of the attachment AT and the suspended load at the rear side. [[ID=1,7]]

[0016] The attachment AT suspends and transports a suspended load. The attachment AT is constituted by a boom 6 including a lower boom 61 connected to the boom attachment portion of the upper slewing body 3 so as to be able to rise and fall, an intermediate boom 62 connected to the tip of the lower boom 61, and an upper boom 63 connected to the tip of the intermediate boom 62. The boom 6 has sufficient rigidity by assembling a plurality of frames.

[0017] The boom 6 can change the length of the attachment AT by increasing or decreasing a plurality of intermediate booms 62 that can be connected to each other. Further, the attachment AT has a backstop 64 for restricting the backward rotation of the boom 6 at the rear side of the tip of the lower boom 61.

[0018] Furthermore, the crane 100 includes a pendant rope 66, an upper spreader 67, a lower spreader 68, a boom luffing wire rope 69, a gantry 71, and a gantry lifting cylinder 72.

[0019] One end of the pendant rope 66 is connected to the rear end of the upper boom 63. The other end of the pendant rope 66 is connected to the upper spreader 67. The upper spreader 67 connects the pendant rope 66 to the boom luffing wire rope 69. The boom luffing wire rope 69 is wound around the boom luffing winch 31 provided on the upper slewing body 3, and is wound in or unwound based on the drive of the boom luffing winch 31.

[0020] The lower spreader 68 is attached to the tip of the gantry 71, which is provided to be able to raise and lower relative to the upper rotating body 3. The gantry lifting cylinder 72 is provided on the upper rotating body 3 and raises and lowers the gantry 71.

[0021] For example, the crane 100 raises the gantry 71 using the gantry lifting cylinder 72 while winding up the boom luffing wire rope 69 using the boom luffing winch 31. This causes the crane 100 to pull the pendant rope 66 via the upper spreader 67, rotating the boom 6 backward and upward. Conversely, the crane 100 can rotate the boom 6 forward and downward by unwinding the boom luffing wire rope 69 using the boom luffing winch 31.

[0022] The crane 100 is equipped with a boom hook 81, a wire rope 82, and a hook overwinding prevention device 83 for holding the suspended load. The boom hook 81 is suspended from the wire rope 82 via a hook bracket 811. In other words, the boom hook 81 constitutes the lower end of the wire rope 82. The hook bracket 811 has a pulley (not shown) inside through which the wire rope 82 is passed.

[0023] One end of the wire rope 82 is fixed to a fixing part provided at the tip of the boom 6. This wire rope 82 extends downward to the hook bracket 811 of the boom hook 81, then folds back from the hook bracket 811 and extends upward. Furthermore, the wire rope 82 is stretched over a point sheave 651 provided at the tip of the boom 6 and extends to the rear side of the boom 6, and is wound around the front winch 32 provided on the upper slewing body 3 from the rear side of the tip of the boom 6. In addition, a hook overwinding prevention device 83 is provided on the wire rope 82 and defines the upper limit of the boom hook 81.

[0024] The crane 100 can raise the boom hook 81 and lift a load by winding up the wire rope 82 with the front winch 32. Conversely, the crane 100 can lower the boom hook 81 and lower a load by unwinding the wire rope 82 with the front winch 32.

[0025] Next, the configuration of the drive system and control system of the crane 100 will be explained with reference to Figure 2. Figure 2 is a schematic block diagram showing an example of the configuration of the crane 100 according to this embodiment.

[0026] <Hydraulic drive system> The hydraulic drive system of the crane 100 according to this embodiment includes hydraulic actuators HA that hydraulically drive the lower traveling body 1 (left and right crawlers), the upper slewing body 3, and the attachment AT, respectively. These hydraulic actuators HA include travel hydraulic motors 1ML, 1MR, slewing hydraulic motor 2M, boom luffing hydraulic motor 31M, and front winch hydraulic motor 32M, etc.

[0027] The slewing hydraulic motor 2M is an actuator for slewing the upper slewing body 3 relative to the lower traveling body 1. The boom luffing hydraulic motor 31M is an actuator for operating the boom luffing winch 31. The front winch hydraulic motor 32M is an actuator for operating the front winch 32.

[0028] Furthermore, the hydraulic drive system of the crane 100 includes an engine 11, a main pump 14, a pilot pump 15, a control valve unit 17, and a regulator 18.

[0029] Engine 11 is the prime mover and the main power source in the hydraulic drive system. Engine 11 is, for example, a diesel engine that uses light oil as fuel. Engine 11 is mounted, for example, at the rear of the upper slewing body 3. Under the control of the controller 30, which will be described later, engine 11 rotates at a constant speed at a preset target speed and drives the main pump 14 and the pilot pump 15.

[0030] The main pump 14 supplies hydraulic fluid to the control valve unit 17 through a high-pressure hydraulic line. The main pump 14 is mounted at the rear of the upper slewing body 3, for example, similar to the engine 11. The main pump 14 is, for example, a variable displacement hydraulic pump, and under the control of the controller 30, the piston stroke length is adjusted by adjusting the tilt angle of the swash plate by the regulator 18, thereby controlling the discharge flow rate (discharge pressure) of the hydraulic fluid.

[0031] The control valve unit 17 is a hydraulic control device that controls the hydraulic actuator HA in response to the operator's operation of the operating device 38, the content of remote operation, or operation commands related to the automatic operation function output from the controller 30. The control valve unit 17 is mounted, for example, in the center of the upper slewing body 3. The control valve unit 17 is connected to the main pump 14 via a high-pressure hydraulic line and selectively supplies hydraulic fluid supplied from the main pump 14 to each hydraulic actuator in response to the operator's operation or operation commands output from the controller 30. Specifically, the control valve unit 17 includes a plurality of control valves (e.g., directional control valves) that control the flow rate and direction of the hydraulic fluid supplied from the main pump 14 to each hydraulic actuator HA.

[0032] <Operation system> The operating system of the crane 100 includes a pilot pump 15, a controller 30, a proportional valve 29, an operating device 38, and an operating sensor 39.

[0033] The pilot pump 15 supplies pilot pressure to various hydraulic devices via the pilot line 25. The pilot pump 15 is mounted, for example, at the rear of the upper slewing body 3, similar to the engine 11. The pilot pump 15 is, for example, a fixed-displacement hydraulic pump. The pilot pump 15 may be omitted. In this case, the relatively high-pressure hydraulic fluid discharged from the main pump 14 is reduced in pressure by a predetermined pressure reducing valve, and the resulting relatively low-pressure hydraulic fluid is supplied to the various hydraulic devices as pilot pressure.

[0034] The control device 38 is located near the cockpit of the cabin 4 and is used by the operator to perform various operations on the crane 100. The control device 38 includes pedal and lever devices for operating each hydraulic actuator HA.

[0035] For example, the operating device 38 is electrically operated. The operating sensor 39 detects the direction and amount of operation of the operating device 38 by the operator and outputs an operating signal corresponding to each operated actuator to the controller 30.

[0036] The controller 30 then outputs a control command to the proportional valve 29 that corresponds to the content of the operation signal, that is, a control signal corresponding to the operation of the operating device 38. As a result, the proportional valve 29 inputs a pilot pressure corresponding to the operation of the operating device 38 to the control valve unit 17, and the control valve unit 17 can drive each hydraulic actuator HA according to the operation of the operating device 38. Note that the control valve (directional control valve) that drives each hydraulic actuator built into the control valve unit 17 may be of the electromagnetic solenoid type. In this case, the operation signal output from the operating device 38 may be directly input to the control valve unit 17 (electromagnetic solenoid type control valve).

[0037] A proportional valve 29 is provided for each hydraulic actuator HA that is operated by the operating device 38. The proportional valve 29 is located in the pipeline connecting the pilot pump 15 and the pilot port of the control valve in the control valve unit 17, and is configured to change the flow area of ​​the pipeline. The proportional valve 29 operates in accordance with the control command output by the controller 30. Therefore, the controller 30 can supply the hydraulic fluid discharged by the pilot pump 15 to the control valve of each hydraulic actuator HA provided in the control valve unit 17 via the proportional valve 29, independently of the operator's operation of the operating device 38.

[0038] <User Interface System> The user interface system of the crane 100 includes an operating device 38, an operating sensor 39, a display device D1, and an input device D2.

[0039] The display device D1 outputs various information to the operator of the crane 100 inside the cabin 4. The display device D1 is installed in a location easily visible to the operator seated inside the cabin 4 and is a device for outputting various information in a visual manner, such as a liquid crystal display or an organic EL (electroluminescence) display.

[0040] The input device D2 is located within close proximity to the operator seated in the cabin 4 and receives various inputs from the operator. The input signals received by the input device D2 are taken up by the controller 30. For example, the input device D2 may include a touch panel mounted on the display device, a touch pad installed around the display device, a button switch, a lever, a toggle, a knob switch provided on the operating device 38 (lever device), etc. Alternatively, the input device D2 may be a voice input device that receives voice input from the operator. A voice input device may include, for example, a microphone. Or, the input device D2 may be a gesture input device that receives gesture input from the operator. A gesture input device may include, for example, an imaging device (indoor camera) installed in the cabin 4.

[0041] <Communications System> The communication system of the crane 100 includes a communication device T1 capable of communicating with external devices. The communication device T1 is connected to a communication line and communicates with devices provided separately from the crane 100. Examples of devices provided separately from the crane 100 include portable communication terminals carried by workers at the work site. The communication device T1 may also include a mobile communication module compliant with standards such as 4G (4th Generation) or 5G (5th Generation). For example, the communication device T1 may also include a satellite communication module, a Wi-Fi® communication module, or a Bluetooth® communication module.

[0042] <Control System> The control system of the crane 100 includes, for example, a slewing sensor S1, a boom luffing sensor S2, a length sensor S3, an upper slewing body positioning device PS, a surrounding recognition device ES, a storage device ST, and a controller 30.

[0043] The rotation sensor S1 outputs information regarding the rotation of the upper rotating body 3. The rotation sensor S1 detects, for example, the rotational angular velocity of the upper rotating body 3 relative to the lower traveling body 1. Furthermore, the rotation sensor S1 detects the rotation angle. The rotation sensor S1 may be, for example, a gyro sensor, resolver, rotary encoder, or IMU (Inertial Measurement Unit). The detection signal corresponding to the rotation angle or rotational angular velocity of the upper rotating body 3 detected by the rotation sensor S1 is input to the controller 30.

[0044] The boom luffing sensor S2 outputs information regarding the luffing of the boom 6. The boom luffing sensor S2 detects, for example, the luffing angle (tilt angle) of the boom 6. The boom luffing sensor S2 may be, for example, a gyro sensor or an IMU. The detection signal corresponding to the luffing angle of the boom 6 from the boom luffing sensor S2 is input to the controller 30.

[0045] The length sensor S3 outputs information regarding the length of the wire rope 82 used to suspend the load with the boom hook 81. The length sensor S3 is, for example, an encoder installed on the front winch 32, which detects the length of the wire rope 82 unwound from the front winch 32.

[0046] The upper slewing body positioning device PS measures the position of the upper slewing body 3. The upper slewing body positioning device PS is, for example, a GNSS (Global Navigation Satellite System) positioning device and detects the position and orientation of the upper slewing body 3. The detection signals corresponding to the position and orientation of the upper slewing body 3 are received by the controller 30. The function of detecting the orientation of the upper slewing body 3 may be realized by an orientation sensor attached to the upper slewing body 3. The upper slewing body positioning device PS measures the current position of the crane 100 in a set reference coordinate system.

[0047] A reference coordinate system is, for example, the World Geodetic System, which can determine a location on Earth. The World Geodetic System is a three-dimensional orthogonal XYZ coordinate system with its origin at the Earth's center of mass, the X-axis pointing towards the intersection of the Greenwich Meridian and the equator, the Y-axis pointing towards 90 degrees east longitude, and the Z-axis pointing towards the North Pole.

[0048] The peripheral recognition device ES is installed, for example, on the front side of the ceiling of the cabin 4 and acquires information about the area outside the crane 100. This peripheral recognition device ES is composed of one or more of the following: an imaging device such as a monocular camera or stereo camera, LiDAR, an ultrasonic sensor, or other optical sensors. The information acquired by the peripheral recognition device ES is converted into information that can be recognized by the controller 30 through well-known image processing, etc., and is input into the controller 30. The peripheral recognition device ES may be installed at any position on the crane 100, for example, on the counterweight 5.

[0049] The storage device ST is, for example, a read / write non-volatile storage medium. This storage device ST can be, for example, an SSD (Solid State Drive) or an HDD (Hard Disk Drive).

[0050] The controller 30 controls the operation of each drive unit provided on the crane 100. The functions of the controller 30 may be realized by any hardware, or any combination of hardware and software. For example, the controller 30 is mainly composed of a computer including a CPU (Central Processing Unit), memory devices such as RAM (Random Access Memory), non-volatile auxiliary storage devices such as ROM (Read Only Memory), and various input / output interface devices. The controller 30 realizes various functions by loading programs installed in the auxiliary storage device into the memory device and executing them on the CPU.

[0051] For example, the controller 30 controls the operation of the hydraulic actuator HA of the crane 100 based on the operation of the operating device 38, with the proportional valve 29 as the control target. The controller 30 may also provide operation support to assist in transporting the suspended load to the target position on the ground surface of the crane 100 (for example, the plane of a two-dimensional coordinate system of XY coordinates). Operation support for the crane 100 may include fully automatic operation that controls the operation of the entire crane 100, semi-automatic operation that controls some of the operations of the crane 100, and a guidance function that displays the operation of the crane 100 on the display device D1 (or outputs it from the speaker).

[0052] As an example, in the crane 100, while the operator controls the lifting and lowering of the suspended load, the controller 30 automatically controls the slewing and luffing of the crane 100, resulting in semi-automatic operation. In other words, the controller 30 controls only the slewing of the upper slewing body 3 and the luffing of the boom 6 to move the boom hook 81 to the target position in the two-dimensional coordinate system. For example, the controller 30 outputs current to the proportional valve 29 to apply an appropriate pilot pressure to the control valve unit 17. This allows the crane 100 to automatically control the slewing hydraulic motor 2M and the boom luffing hydraulic motor 31M.

[0053] In order to perform the above-mentioned semi-automatic operation, the controller 30 internally constructs an acquisition unit 301, an operation reception unit 302, a display control unit 303, a registration unit 304, a position recognition unit 305, a trajectory generation unit 306, and a control unit 307 under the execution of a program by the CPU.

[0054] The acquisition unit 301 acquires detection results from various sensors installed on the crane 100. For example, the acquisition unit 301 acquires operation signals from the operation sensor 39 that indicate operations on the operation device 38 operated by the operator. The acquisition unit 301 also acquires information on the rotational velocity and rotational angle of the upper rotating body 3 from the rotation sensor S1, information on the luffing of the boom 6 (e.g., luffing angle) from the boom luffing sensor S2, and information on the length of the wire rope 82 from the length sensor S3. Furthermore, the acquisition unit 301 acquires information detected by the surrounding recognition device ES (e.g., imaging information).

[0055] The acquisition unit 301 may calculate the height of the suspended load from the length of the wire rope 82 and the elevation angle of the boom 6 when acquiring data from various sensors. The controller 30 may also calculate the position of the suspended load (two-dimensional coordinates, or three-dimensional coordinates including height) based on the information of the suspended load detected by the surrounding recognition device ES.

[0056] The operation reception unit 302 receives operations from the operator via one or more of the input device D2 and the operation device 38. For example, the operation reception unit 302 receives a press of a predetermined button on the operation device 38 in order to switch to the simplified operation mode, which is a mode for performing semi-automatic operation. The "simplified operation mode" is an operation mode for transporting a suspended load from the current starting position (first position) to a pre-registered target position (second position) when an input operation of the slewing operation lever of the operation device 38 is received.

[0057] The display control unit 303 performs control for displaying information on the display device D1. For example, when the display control unit 303 receives an operation to switch to the simplified operation mode, it displays the simplified operation mode screen.

[0058] In the simplified operation mode, the registration unit 304 registers the target position used for transporting the suspended load in the storage device ST. For example, before operation assistance is activated, the operator manually operates the upper slewing body 3 and boom 6 so that the suspension pivot point 6S, which is the tip of the boom 6, aligns vertically with the target position. Then, with the suspension pivot point 6S positioned at the target position, the operator presses the target button to register the current position of the suspension pivot point 6S as the target position. In this way, by memorizing the position manually operated by the operator, it becomes possible to set the target position with high accuracy within the range of motion of the boom 6.

[0059] Alternatively, another registration method may involve calculating (recognizing) the target position based on detection information obtained by a peripheral recognition device ES installed on the crane 100. Another registration method may involve placing a positioning device such as a GNSS positioning device at the target position and receiving information about the target position determined by this positioning device. Alternatively, another registration method may involve detecting the position of the target using an external device (imaging device, LiDAR, distance sensor, other object recognition sensor) installed outside the crane 100 and receiving information about the position of the target position TP from this external device.

[0060] The recognized target position may be a two-dimensional coordinate system in the World Geodetic System, or it may be a three-dimensional coordinate system including height information obtained by measuring altitude using a pressure sensor. Furthermore, when the registration unit 304 stores the target position, it may convert the position information so that the target position is placed in a crane coordinate system based on the upper rotating body 3 of the crane 100.

[0061] The position recognition unit 305 recognizes the current position of the tip of the boom 6 and / or the current position of the boom hook 81, which is the lower end of the wire rope 82. The tip of the boom 6 is provided with a point sheave 651 from which the wire rope 82 is suspended, and a sheave bracket 650 that rotatably supports the point sheave 651 (see Figure 1). In other words, the tip of the boom 6 is the suspension pivot point 6S from which the wire rope 82 is suspended vertically downward from the point sheave 651 and moves integrally with the boom 6.

[0062] For example, the position recognition unit 305 can recognize the position of the suspension support point 6S and the position of the lower end of the wire rope 82 (boom hook 81, suspended load) based on the detection information of the surrounding recognition device ES. In this case, the position recognition unit 305 may also calculate the inclination angle θ of the suspended load (wire rope 82), which will be described later, based on the position of the suspension support point 6S and the position of the suspended load. Alternatively, the position recognition unit 305 can also recognize the position of the suspension support point 6S based on information from various sensors of the crane 100 (upper slewing body positioning device PS, slewing sensor S1, boom luffing sensor S2, etc.). For example, the crane 100 may have GNSS positioning devices installed on the suspension support point 6S and the boom hook 81. Based on the information obtained by these GNSS positioning devices, the position recognition unit 305 can recognize the position of the suspension support point 6S and the position of the lower end of the wire rope 82, and can also calculate the inclination angle θ.

[0063] The trajectory generation unit 306 generates a target trajectory for automatically transporting the boom hook 81 and the suspended load from the starting position (current position) of the suspension support unit 6S to the target position in a two-dimensional coordinate system representing the ground contact surface of the crane 100. A well-known method can be used for generating the target trajectory. For example, the trajectory generation unit 306 generates the target trajectory based on the difference in the slewing angle between the current position of the tip of the boom 6 and the target position, and the difference between the current elevation angle of the boom 6 and the elevation angle when the boom hook 81 reaches the target position.

[0064] As an example, the trajectory generation unit 306 calculates a target trajectory in which the lower end of the wire rope 82 moves as short a distance as possible, based on the starting position of the suspension support unit 6S, the target position, the rotational capability of the upper slewing body 3, the luffing capability of the boom 6, etc. However, in generating the target trajectory, the rotational movement may be prioritized, and a target trajectory that minimizes the luffing movement of the boom 6 may be calculated. This can suppress vibrations and loads on the boom 6 that occur during the luffing movement of the boom 6 when rotating.

[0065] The control unit 307 controls the movement of the upper slewing body 3 and boom 6 of the crane 100 based on the target trajectory generated by the trajectory generation unit 306. For example, the control unit 307 controls the upper slewing body 3 and boom 6 to move the suspension pivot 6S along the target trajectory from the starting position to the target position in a two-dimensional coordinate system with respect to the crane 100.

[0066] Furthermore, when the control unit 307 moves the boom hook 81 and the suspended load from the starting position to the target position, it controls the position of the suspension support point 6S to precede the position of the lower end of the wire rope 82 (boom hook 81, suspended load), causing the lower end of the wire rope 82 to follow. As the lower end of the wire rope 82 moves in accordance with the suspension support point 6S, the swaying of the lower end of the wire rope 82 is suppressed (therefore, this control will also be referred to as sway suppression control below). The sway suppression control according to this embodiment will be described in detail later.

[0067] The following describes the operation of the crane 100 in semi-automatic operation, specifically the automatic movement of the suspension fulcrum 6S at the tip of the boom 6 from the starting position to the target position TP, with reference to Figure 3. Figure 3 is a plan view showing the movement of the suspension fulcrum 6S of the crane 100 from the starting position to the target position TP. Note that the control to move the suspension fulcrum 6S from the starting position to the target position TP may be performed even if there is no load HL suspended from the boom hook 81, or even if the load HL is suspended from the boom hook 81.

[0068] Here, the boom hook 81 (the lower end of the wire rope 82) of the crane 100 is basically suspended vertically downward from a point sheave 651 provided at the suspension support point 6S. Therefore, when moving the boom hook 81 to the target position TP, it is sufficient to move it so that the suspension support point 6S aligns with the target position TP in a plan view (on a two-dimensional coordinate system).

[0069] Therefore, in the embodiment, the controller 30 recognizes the position of the suspension support point 6S and the target position TP before the movement of the upper slewing body 3 and the boom 6 during semi-automatic operation. Furthermore, the controller 30 generates a target trajectory in a two-dimensional or three-dimensional coordinate system from the recognized position of the suspension support point 6S (starting position) to the target position TP. The controller 30 then automatically moves the suspension support point 6S by controlling the rotation of the upper slewing body 3 and the elevation of the boom 6 to follow the target trajectory.

[0070] The position of the suspension support point 6S can be recognized based on information from various sensors of the crane 100 (detection information from the surrounding recognition device ES, or detection information from the upper slewing body positioning device PS, slewing sensor S1, boom luffing sensor S2, etc.), as described above. The target position TP can be set via registration by the registration unit 304, as described above. The target position is not limited to the position where the suspended load HL is lowered or the position where the suspended load HL is lowered, but may also be an intermediate position when moving the lower end of the wire rope 82. In other words, the "second position" in this disclosure may be any of the position where the suspended load HL is lowered, the position where the suspended load HL is lowered, or the intermediate position during movement. Similarly, the "first position" in this disclosure may be the current position of the suspension support point 6S, the intermediate position, or the position set for starting movement.

[0071] The process of registering the target position TP will be described below with reference to Figure 4. Figure 4 is a flowchart showing an example of the procedure for registering the target position TP in the simplified operation mode in the controller 30 according to the embodiment. When setting the target position TP to move the suspension support part 6S, the controller 30 executes, for example, the flowchart shown in Figure 4.

[0072] Specifically, the display control unit 303 first controls the display of the simplified operation mode screen on the display device D1 (S101).

[0073] Figure 5 is an example of the screen in the simplified operation mode displayed by the display control unit 303. The screen in the simplified operation mode displays, for example, a display area 1410, a first target button 1401, a second target button 1402, a third target button 1403, a setting button 1404, and a two-point setting button 1405.

[0074] Display area 1410 shows a coordinate system that represents the working range of the crane 100 in two dimensions. Reference position 1411 indicates the pivot center of the crane 100.

[0075] The triangular shape 1412 and the circular icon 1413 indicate the current state of the boom 6. Specifically, the triangular shape 1412 indicates the length of the boom 6 based on its current orientation and elevation, while the circular icon 1413 indicates the suspension support point 6S at the tip of the boom. The length of the triangular shape 1412 from the reference position 1411 to the circular icon 1413 becomes shorter as the boom 6 rises and longer as the boom 6 is lowered.

[0076] Circle 1450 is the circle that indicates the longest distance that the tip of boom 6 can reach. Circles 1451 and 1452 are circles that indicate predetermined distances.

[0077] The first target button 1401, the second target button 1402, and the third target button 1403 are buttons for positioning the target position TP in a coordinate system (two-dimensional coordinates in Figure 7) based on the crane 100. In other words, in this embodiment, three target positions corresponding to the first target button 1401, the second target button 1402, and the third target button 1403 can be registered. In the display area 1410, the registered target position TP is indicated by an X icon 1414.

[0078] For example, when the first target button 1401 is pressed and held by the operator, the acquisition unit 301 acquires the location information of the target position TP based on the method for acquiring the target position TP described above. The registration unit 304 then converts the location information of the target position TP into a two-dimensional coordinate system based on the crane 100 and registers it, and also displays an X icon 1414 in the display area 1410.

[0079] In assisting the operation of the crane 100, the controller 30 presses one of the first target button 1401, the second target button 1402, or the third target button 1403 to read the registered target position TP and moves the suspension support unit 6S to this target position TP. However, the target position TP of the suspension support unit 6S does not have to be the final destination. For example, after moving the suspension support unit 6S to the first target position, it may be moved again to the second target position.

[0080] Additionally, the setting button 1404 is a button provided for making various settings. The two-point setting button 1405 is a button used when the boom hook 81 of the crane 100 moves between two positions.

[0081] Returning to Figure 4, the operation reception unit 302 determines whether or not it has received a registration operation by pressing and holding the first target button 1401, the second target button 1402, or the third target button 1403 (S102). If it determines that it has not received a registration operation (S102: NO), it terminates without performing any further processing.

[0082] On the other hand, if the operation reception unit 302 determines that it has received a registration operation by pressing and holding the first target button 1401, the second target button 1402, or the third target button 1403 (S102: YES), the acquisition unit 301 acquires the location information of the target position TP using the method described above (S103).

[0083] The registration unit 304 stores the identified location information in the storage device ST in association with the long-pressed target button (first target button 1401, second target button 1402, or third target button 1403) (S104). At this time, the display control unit 303 displays the acquired target location TP on the display device D1. For example, the display control unit 303 displays the target location TP in relation to the boom 6 in the display area 1410, which is a coordinate system based on the crane 100. In addition, the color of the target button for which location information has been registered may be different from the color of the target button for which location information has not been registered. This allows the operator to recognize the target button for which location information has been registered when referring to the screen in the simplified operation mode. The controller 30 can register the location information of the target location TP by performing the above control.

[0084] Next, the process of controlling the movement of the boom 6 using the simplified operation mode will be explained with reference to Figure 6. Figure 6 is a flowchart illustrating the procedure by which the controller 30 controls the movement of the boom 6 in the simplified operation mode.

[0085] The display control unit 303 of the controller 30 controls the display of the simplified operation mode screen on the display device D1 (S111).

[0086] Next, the operation reception unit 302 determines whether or not it has received an operation to read location information by pressing the target button (S112). If it determines that it has not received an operation to read location information by pressing the target button (S112: NO), the process ends.

[0087] On the other hand, if the operation reception unit 302 determines that it has received a request to read position information (S112: YES), the acquisition unit 301 acquires position information of the current position of the suspension support point 6S provided at the tip of the boom 6 (S113). The acquisition unit 301 acquires position information of the suspension support point 6S based on the method for acquiring the position of the suspension support point 6S described above. Furthermore, when the display control unit 303 acquires the current position of the suspension support point 6S, it is preferable to perform a calibration process to align the coordinate system of the crane 100 with the current position of the suspension support point 6S.

[0088] Next, when position information corresponding to the target button pressed by the operator is read from the storage device ST, the trajectory generation unit 306 generates a target trajectory for the suspension pivot 6S based on the current position of the suspension pivot 6S and the target position TP (S114).

[0089] The display control unit 303 then displays the current position, target position TP, and target trajectory of the suspension support unit 6S in the display area 1410 (S115). This allows the operator to confirm the target trajectory as the suspension support unit 6S moves by the semi-automatic operation by the controller 30. Therefore, the operator can visually check the area around the crane 100 before the semi-automatic operation starts to confirm whether the boom hook 81, etc., will come into contact with any obstacles when the suspension support unit 6S moves along the target trajectory.

[0090] Subsequently, the operation reception unit 302 determines whether or not it has received a rotation operation from the rotation operation lever included in the operation device 38 (S116). If the operation reception unit 302 determines that it has received a rotation operation from the rotation operation lever (S116: YES), the process proceeds to S117.

[0091] The control unit 307 controls the drive of either or both of the slewing hydraulic motor 2M and the boom luffing hydraulic motor 31M so that the suspension support section 6S moves along the target trajectory (S117). Then, based on the acceptance of a slewing operation, the control unit 307 moves the suspension support section 6S to the target position TP. At this time, the control unit 307 may control the system to maintain the height position of the suspended load by simultaneously performing slewing control to slewing the upper slewing body 3 at a constant slewing speed and luffing control to luff the boom 6 at a constant luffing speed.

[0092] The display control unit 303 changes the display within the display area 1410 of the simplified operation mode screen in accordance with the rotation control and elevation control while rotation control and elevation control are being performed. For example, the display control unit 303 may change the orientation and length of the triangular shape 1412 and the circular icon 1413 in accordance with the movement of the crane 100. Alternatively, the display control unit 303 may not change the orientation of the triangular shape 1412, but may change the length of the displayed triangular shape 1412, the target position TP, and the target trajectory in accordance with the movement of the crane 100.

[0093] Furthermore, the crane 100 according to this embodiment performs sway suppression control (S118) to ensure that the lower end of the wire rope 82 (boom hook 81 and / or suspended load HL) continuously follows the suspension pivot 6S during movement of the suspension pivot 6S. As a result, the crane 100 suppresses the sway of the wire rope 82 when the boom 6 moves, and the boom hook 81 and / or suspended load HL can be moved stably. In addition, while the crane is controlling the movement of the suspension pivot 6S to the target position, the operator may monitor whether the boom hook 81 or suspended load HL is in contact with an obstacle, and may perform a hoisting or lowering operation if it appears that it is about to come into contact with an obstacle. The control unit 307 adjusts the height of the boom hook 81 or suspended load by hoisting or lowering in response to the operation, thereby avoiding contact with obstacles, etc.

[0094] On the other hand, if the control unit 307 determines that it has not received a slewing operation via the slewing operation lever (S116: NO), it does not control the drive of the slewing hydraulic motor 2M and the boom luffing hydraulic motor 31M. Also, if the acceptance of slewing operations is stopped before the suspension support part 6S moves to the target position TP, the control unit 307 stops the slewing control of the upper slewing body 3 and the luffing control of the boom 6. This allows the operator to stop semi-automatic operation if they recognize an obstacle or the like at the destination of the boom hook 81 and the suspended load by visual inspection, etc.

[0095] The control unit 307 then determines whether the suspension pivot 6S has reached a position close to the target position TP on the target trajectory (S119). If it determines that it has not reached a position close to the target position (S119: NO), it returns to S116 and performs the same processing again.

[0096] On the other hand, if the control unit 307 determines that the suspension pivot 6S has reached a position close to the target position TP on the target trajectory (S119: YES), it performs stop control to stop the movement while suppressing the swaying of the suspended load HL (S120). By stopping the movement of the suspension pivot 6S through this stop control, the swaying of the boom hook 81 or the suspended load HL subsides early above the target position TP. Therefore, the operator of the crane 100 can then smoothly lower the boom hook 81 or the suspended load HL to the target position TP by lowering the wire rope 82.

[0097] <Shake suppression control> Next, we will explain the sway suppression control (step S118 in Figure 6) that suppresses the swaying of the boom hook 81 or the suspended load HL during the movement of the suspension support point 6S, referring to Figures 7 and 8(A) to 8(C). In the following explanation, we will describe the case where the suspended load HL is suspended from the boom hook 81 (therefore, the lower end of the wire rope 82 is also referred to as the suspended load HL). Figure 7 is a plan view illustrating the target trajectory from the starting position to the target position TP when there is an obstacle. Figures 8(A) to 8(C) are the first to third explanatory diagrams showing the relationship between the position of the suspension support point 6S and the position of the suspended load HL in the sway suppression control.

[0098] In the automatic transport (semi-automatic operation) of the suspended load HL, the control unit 307 controls the movement of the suspension pivot 6S using the target trajectory generated by the trajectory generation unit 306 (see Figure 2) as described above. In generating this target trajectory, the acquisition unit 301 (see Figure 2) acquires information about the area around the crane 100 using the surrounding recognition device ES (imaging device, LiDAR, etc.) provided on the crane 100, and detects the presence or absence of obstacles or other objects in the surrounding area. If an obstacle is present near the crane 100, the controller 30 reflects the detected obstacle in the recognized coordinates (two-dimensional coordinates, three-dimensional coordinates, etc.) as shown in Figure 7. Then, the trajectory generation unit 306 generates a target trajectory that avoids the obstacle based on the position of the detected obstacle.

[0099] A target trajectory for avoiding obstacles is one that maintains a minimum distance to some extent, causes the boom 6 to perform only one elevation movement (raising or lowering), and is a path that can avoid obstacles. However, the trajectory generation unit 306 may generate a target trajectory that is not limited to such a target trajectory, but rotates the upper slewing body 3 in the opposite direction to move the suspension support part 6S to the target position TP.

[0100] The generated target trajectory can be represented on a two-dimensional coordinate system using a function of position, such as a polynomial function (e.g., a linear function, quadratic function, ..., an Nth-degree function), or other rational or irrational functions. The trajectory generation unit 306 sets plots whose positions change at regular intervals along this target trajectory. For example, as shown in Figure 7, the target trajectory has plot 1 (X1, Y1), plot 2 (X2, Y2), plot 3 (X3, Y3), ... plot N (Xn, Yn). Note that in Figure 7, the number of plots is shown in a limited number for ease of understanding. The actual number of plots in the target trajectory depends on the distance from the starting position to the target position, but can be set to a range of, for example, tens to thousands. In other words, the target trajectory is represented as a continuous path on a two-dimensional coordinate system by connecting the line segments that connect each plot (X coordinate, Y coordinate).

[0101] As described above, the suspension support point 6S suspends the boom hook 81 and / or the load HL from the lower end of the wire rope 82 that extends vertically downward (see also Figure 8(A)). Therefore, the position of the suspension support point 6S can be expressed by the equation of motion of the load HL (the lower end of the wire rope 82) suspended from the suspension support point 6S. This equation of motion can be a linear sum of the position, velocity, and acceleration of the load HL.

[0102] For example, in sway suppression control, a linear combination equation of motion is defined between the positions xc and yc of the suspension support 6S and the positions xm and ym of the suspended load, as shown in equation (1) below.

[0103]

number

[0104] As described above, equation (1) has acceleration. This acceleration can be expressed by the equation of motion as the force acting on the suspended load HL. Furthermore, the swaying of the suspended load HL can be understood as being caused by the force acting on it. Therefore, if the equation of motion for the target trajectory is such that it cancels out the force (acceleration) acting on the suspended load HL, then it can be said that the swaying of the suspended load HL can be suppressed and the suspended load HL can be moved.

[0105] Therefore, in the sway suppression control, the controller 30 calculates the constants A, B, C, D, E, and F of the linear sum in equation (1) such that the positions xc and yc of the suspension support 6S always precede the positions xm and ym of the suspended load HL. The state in which the position of the suspension support 6S precedes the position of the suspended load HL refers to the state in which the suspended load HL (wire rope 82) is inclined at an appropriate inclination angle θ with respect to the suspension support 6S, as shown in Figures 8(A) to 8(C). In equation (1), the constants A, B, and C to the right of xc and the constants D, E, and F to the right of yc may be the same value or may be different values.

[0106] The control unit 307 controls the rotation of the upper slewing body 3 and the elevation of the boom 6, while guiding the suspension support section 6S along the target trajectory, based on the position, velocity, and acceleration of the suspension support section 6S corresponding to the calculated constants A, B, C, D, E, and F. This allows the suspension support section 6S to move along the line segments connecting each plot of the target trajectory, while suppressing the acceleration acting on the suspended load HL and allowing it to follow the suspended load HL. The controller 30 may also correct the target trajectory previously generated by the trajectory generation unit 306 in conjunction with the calculation of the position, velocity, and acceleration of the suspension support section 6S to suppress the swaying of the suspended load HL. For example, if the acceleration of the suspended load HL becomes large, the target trajectory may be corrected to subtract the acceleration from the position and velocity of the suspended load HL. The crane 100 can reduce the sway of the suspended load HL during its horizontal movement by moving the suspension support 6S along the corrected target trajectory.

[0107] Specifically, as shown in Figure 8(A), at the starting position of the suspension support section 6S, when the suspension support section 6S begins to move, the position of the suspension support section 6S moves while the position of the suspended load HL remains unchanged. This is because the suspended load HL maintains its inertia from when it stopped. As a result, the wire rope 82 is slightly inclined with respect to the imaginary vertical line of the suspension support section 6S.

[0108] Then, as shown in Figure 8(B), when the suspension support point 6S has displaced to a certain extent, the suspended load HL begins to move (the position of the suspended load HL begins to displace). As a result, the inclination angle θ of the suspended load HL temporarily overshoots. However, the controller 30 of the crane 100 controls the movement of the suspension support point 6S as described above, adjusting the movement speed of the suspension support point 6S so that the inclination angle θ calculated after the overshoot is achieved. As a result, the crane 100 can make the suspended load HL follow the suspension support point 6S while maintaining an appropriate inclination angle θ.

[0109] In other words, as shown in Figure 8(C), the suspended load HL maintains an inclination angle θ as it moves in accordance with the suspension support 6S. This allows it to follow only the target trajectory of the suspension support 6S, while suppressing the acceleration (including centrifugal force) acting on the suspended load HL. As a result, the swaying of the suspended load HL in directions other than the direction of movement of the suspension support 6S is suppressed.

[0110] The control unit 307 then continues the sway suppression control from the starting position (current position) of the suspension support 6S in the previously generated target trajectory to the proximity position just before the target position TP. As a result, from the starting position to the proximity position of the target position TP, the suspended load HL is encouraged to move substantially horizontally according to the suspension support 6S rather than being swayed by other external forces. The proximity position of the target position TP refers to a position within a range of approximately 0.1m to 1m before the target position TP. However, the proximity position of the target position TP is not a fixed position in the control system, but may change according to the movement speed of the suspension support 6S and the suspended load HL, etc.

[0111] In the above explanation, an example was described in which a target trajectory is created first, and then parameters for suppressing swaying are calculated based on the equations of motion for the position of the suspension support 6S, the position of the suspended load HL, the velocity of the suspended load HL, and the acceleration of the suspended load HL along that target trajectory. As a result, the crane 100 can appropriately follow the suspended load HL while controlling the movement of the suspension support 6S to follow the target trajectory. However, the controller 30 may also generate the target trajectory by taking into account the parameters for sway suppression control associated with the acceleration of the suspended load HL at the time of target trajectory generation. The controller 30 can also make the suspended load HL follow by controlling the movement of the suspension support 6S based on the position and time of each plot of this target trajectory.

[0112] Furthermore, while Figures 8(A) to 8(C) show an example where the suspended load HL moves in a straight line for ease of understanding, in reality, the crane 100 moves the suspension support section 6S to the target position TP by controlling the rotation of the upper slewing body 3 and the luffing of the boom 6. Therefore, as shown in Figure 9, the control unit 307 converts the position, velocity, and acceleration of the suspension support section 6S along the target trajectory into the rotation angle of the crane 100's operating axis (luffing axis, slewing axis, etc.) to control the operation of the crane 100. Figure 9 is an explanatory diagram showing the relationship between the slewing axis p and luffing axis q of the crane 100 and the various parameters of the crane 100.

[0113] For example, the rotation angle of the pivot axis p of crane 100 can be expressed by the following equation (2).

[0114]

number

[0115] Furthermore, the rotation angle of the luffing axis q of the crane 100 can be expressed by the following equation (3).

[0116]

number

[0117] The control unit 307 sets the amount of movement / control for the rotation angle of the slewing axis p in equation (2) and the rotation angle of the luffing axis q in equation (3) so that the suspension support section 6S moves along the target trajectory. Based on these set rotation angles of the slewing axis p and luffing axis q, the control unit 307 controls the slewing of the upper slewing body 3 and the luffing of the boom 6, thereby smoothly moving the suspension support section 6S and allowing the suspended load HL to follow it well.

[0118] Furthermore, it is preferable for the crane 100 to control the movement of the suspension support section 6S while monitoring the inclination angle θ of the wire rope 82 during the movement of the suspension support section 6S. For this reason, the position recognition unit 305 of the controller 30 detects the positions of the suspension support section 6S, wire rope 82, boom hook 81 and / or suspended load HL using the surrounding recognition device ES when the suspension support section 6S is moving, and calculates the inclination angle θ of the wire rope 82. This allows for good recognition that the suspended load HL is following the suspension support section 6S. However, the detection of the positions or angles of the suspension support section 6S, wire rope 82, boom hook 81 and / or suspended load HL is not limited to using the surrounding recognition device ES. For example, the crane 100 can install a GNSS positioning device on the suspension support point 6S and on the boom hook 81, and by obtaining positioning information from these devices, it can recognize the positions of the suspension support point 6S, the boom hook 81, and / or the suspended load HL. Alternatively, the position or angle of the boom hook 81 and / or the suspended load HL may be monitored using detection information from a peripheral recognition device ES (camera) installed near the tip of the boom 6 (suspension support point 6S).

[0119] Figure 10 shows the change in the inclination angle θ over time as the suspension support point 6S moves. In the graph in Figure 10, the horizontal axis represents time, and the vertical axis represents the inclination angle θ of the wire rope 82. When the inclination angle θ is zero, the suspended load HL is located vertically below the suspension support point 6S. When the inclination angle θ is positive, the suspended load HL is leading the suspension support point 6S. When the inclination angle θ is negative, the suspended load HL is following the suspension support point 6S.

[0120] Time point t0 in Figure 10 is the moment when the suspension support 6S begins to move from its starting position. In the initial period from time point t0 to time point t1, the suspended load HL, as shown in Figure 8(A), behaves in a way that maintains its position. As a result, the suspension support 6S significantly precedes the suspended load HL, creating a transient state in which the inclination angle θ changes significantly to the negative side.

[0121] From time t1 onward, the suspended load HL begins to follow the suspension support 6S. At this time, the control unit 307 controls the movement speed of the suspension support 6S so that the suspended load HL, whose inclination angle θ has changed to the negative side, can catch up to the suspension support 6S to some extent. As a result, the inclination angle θ of the suspended load HL approaches zero on the negative side.

[0122] As described above, the control unit 307 performs sway suppression control to make the suspended load HL follow the suspension support unit 6S. As a result, the suspension support unit 6S moves the suspended load HL while maintaining the inclination angle θ of the suspended load HL on the negative side. However, during movement, the suspended load HL is subjected to disturbances and vibrations from the crane 100, so swaying may occur and it may move ahead of the suspension support unit 6S.

[0123] Then, time t2 is the timing when the suspension support 6S begins to decelerate, based on the fact that the suspended load HL is approaching the target position TP. As the movement speed of the suspension support 6S decreases, the suspended load HL, which is still retaining its inertia during movement, moves ahead of the suspension support 6S. Therefore, at time t3, a transient state occurs in which the inclination angle θ of the wire rope 82 changes significantly to the positive side.

[0124] At this time, the control unit 307 performs stop control to stop the movement of the suspension support 6S and the suspended load HL while suppressing the swaying of the suspended load HL (S120 in Figure 6). As a result, at time t4, the inclination angle θ of the wire rope 82 that has moved to the positive side smoothly returns to near zero, and after returning to near zero, it maintains that state (stopped at the target position TP).

[0125] Next, we will explain in detail the stop control of the suspension support section 6S, referring to Figures 11(A) to 11(F). Figures 11(A) to 11(F) are the first to sixth operation diagrams showing the operation of the suspension support section 6S and the behavior of the suspended load HL during stop control.

[0126] As shown in Figure 11(A), until it reaches a position close to the target position TP, the suspension support point 6S is ahead of the suspended load HL in accordance with the sway suppression control by the crane 100. In addition, the controller 30 continuously recognizes (monitors) the position of the suspension support point 6S based on the detection results of various sensors when the boom 6 moves, and determines whether or not the suspension support point 6S has reached a position close to the target position TP.

[0127] When the suspension support point 6S reaches a position close to the target position TP, the control unit 307 controls the deceleration of the suspension support point 6S, as shown in Figure 11(B). The inertia of the suspended load HL is maintained relative to the movement speed of the suspension support point 6S. As a result, the suspended load HL catches up with the suspension support point 6S. It should be noted that the crane 100 does not need to abruptly decelerate the movement speed of the suspension support point 6S when it is close to the target position TP, but may gradually decelerate the movement speed at a position a certain distance from the position close to the target position TP.

[0128] Furthermore, as shown in Figure 11(C), the suspended load HL overtakes the suspension support 6S due to inertia and comes to lead the suspension support 6S. In stop control, the suspension support 6S is gradually decelerated in relation to the leading suspended load HL, and the sway of the suspended load HL is suppressed by catching up to the maximum amplitude (limit position of amplitude) of the suspended load HL.

[0129] Specifically, as shown in Figure 11(D), when the suspended load HL is ahead of the suspension support 6S, the control unit 307 estimates the maximum amplitude (limit position of amplitude) of the suspended load HL. The limit position can be estimated by the relative movement speed of the suspended load HL with respect to the deceleration of the suspension support 6S. Then, the control unit 307 moves the suspension support 6S to the limit position of the suspended load HL by controlling the gradual and abrupt deceleration of the suspension support 6S so that it coincides with the estimated limit position of the suspended load HL. At the limit position of the suspended load HL, the movement speed of the suspended load HL becomes zero. Therefore, by stopping the suspension support 6S to match the limit position, it is possible to suppress the suspended load HL from swinging (returning) in the opposite direction.

[0130] The control unit 307 should control the movement of the suspension support point 6S so that it moves within a quarter of the period of the swing of the suspended load HL via the wire rope 82. This makes it possible to align the suspension support point 6S with the limit position of the amplitude of the suspended load HL during the period in which it moves to the limit position of the amplitude of the suspended load HL.

[0131] Furthermore, in stop control, as shown in Figure 11(E), it is preferable for the control unit 307 to reduce the deceleration of the suspension support 6S to near zero as the suspension support 6S approaches the limit position of the amplitude of the suspended load HL. This makes it possible to smoothly stop the suspension support 6S at the limit position of the amplitude of the suspended load HL, and suppresses the swaying of the suspended load HL caused by the suspension support 6S exceeding the limit position of the amplitude of the suspended load HL.

[0132] Furthermore, the control unit 307 calculates the inertia of the suspended load HL during the actual movement of the suspension pivot 6S and adjusts the movement speed of the suspension pivot 6S so that the limit position of the amplitude of the suspended load HL coincides with the target position TP. As a result, as shown in Figure 11(F), when the suspension pivot 6S stops at the limit position of the amplitude of the suspended load HL, the suspension pivot 6S and the suspended load HL will be precisely aligned with the target position TP. In other words, the crane 100 can move the suspended load HL relative to the target position TP while suppressing the sway of the suspended load HL.

[0133] Figure 12 shows the action of suppressing the leading of the suspended load HL when the suspended load HL leads the movement of the suspension support point 6S. In the graph of Figure 12, the horizontal axis is time, and the vertical axis is the inclination angle θ of the wire rope 82.

[0134] As described above, the crane 100 controls the suspended load HL to follow the suspension support point 6S. However, during actual movement of the suspended load HL, the suspended load HL may lead the suspension support point 6S due to deviations from the target trajectory of the suspension support point 6S, vibrations of the crane 100, and other disturbances. When the suspended load HL leads the suspension support point 6S, the inclination angle θ of the wire rope 82 changes to a positive value in the graph of Figure 12. In particular, in the sway suppression control that makes the suspended load HL follow the suspension support point 6S, the actual inclination angle θ of the suspended load HL is adjusted to maintain a value close to zero even if it is located on the negative side (see also Figure 10). For this reason, there is a greater possibility that the inclination angle θ of the wire rope 82 will change to a positive value when the suspension support point 6S moves.

[0135] For example, the controller 30 monitors the inclination angle θ of the wire rope 82 based on information about the suspension support point 6S and the lower end of the wire rope 82 (boom hook 81, suspended load HL) acquired by the surrounding recognition device ES. The controller 30 then determines whether the inclination angle θ of the wire rope 82 has changed to a positive side, in other words, whether the suspended load HL is ahead of the suspension support point 6S. If the inclination angle θ of the wire rope 82 has changed to a positive side, the controller 30 performs a follow-up adjustment process to increase the movement speed of the suspension support point 6S. This follow-up adjustment process causes the suspension support point 6S to once again lead the suspended load HL. Alternatively, the controller 30 may perform a follow-up adjustment process to increase the movement speed of the suspension support point 6S when it estimates that the inclination angle θ of the wire rope 82 has changed to a positive side (in other words, that the suspended load HL is ahead of the suspension support point 6S).

[0136] Figure 13 is a graph showing the changes in the tilt angle of the suspended load HL, the change in the speed command value, and the change in the slewing speed when follow adjustment processing is performed in sway suppression control. As described above, the controller 30 calculates the tilt angle θ of the suspended load HL relative to the suspension support 6S based on the detection by the surrounding recognition device ES. The controller 30 has a threshold value in advance for monitoring the state of the suspended load HL and determines whether the tilt angle θ has exceeded the threshold value. The reference position of the tilt angle in the graph is the target tilt angle for maintaining follow of the suspended load HL in sway suppression control.

[0137] The threshold for determining the inclination angle θ may be set to a positive value, a negative value, or zero. For example, using a threshold set to a positive value allows for the determination of a state where the suspended load HL has reliably preceded the suspension support 6S. Alternatively, using a threshold set to a negative value allows for the prediction that the suspended load HL will exceed the suspension support 6S before it precedes it. However, when predicting that the suspended load HL will exceed the suspension support 6S, it is preferable to consider the rate of change of the inclination angle θ and determine that the threshold is exceeded in patterns where the inclination angle θ is changing significantly.

[0138] When the control unit 307 of the controller 30 determines that the inclination angle θ of the suspended load HL has exceeded a threshold at time tα, it changes the speed command value for the direction of movement of the suspension support section 6S. For example, as shown in Figure 13, if the upper slewing body 3 is slewing to the right, the speed command value for the right slewing is increased from time t1 when the inclination angle θ exceeds the threshold. As a result, the movement speed (slewing speed) of the tip of the boom 6 supported by the upper slewing body 3 of the crane 100 increases. In other words, the movement of the suspension support section 6S is controlled to overtake the preceding suspended load HL, causing the suspended load HL to follow again.

[0139] After overtaking the suspended load HL at time tβ (after the inclination angle θ reaches the reference position), the controller 30 again performs swing suppression control of the suspended load HL by the suspension support section 6S. If the position of the suspension support section 6S deviates from the target trajectory due to this tracking adjustment process, the target trajectory should be corrected, and the rotation control of the upper slewing body 3 and the luffing control of the boom 6 should be performed to follow the corrected target trajectory. However, the controller 30 controls the suspension support section 6S, which increased its speed to overtake the suspended load HL, to gradually decrease its speed. As a result, the crane 100 can gradually reduce the speed of the suspended load HL while maintaining the positional relationship between the suspension support section 6S and the suspended load HL, making it possible to suppress the swing of the suspended load HL when stopped, etc.

[0140] Furthermore, the work machine (crane 100) relating to this disclosure is not limited to the above-described embodiment and can take various modifications. For example, the work machine is not limited to a crane applied to a construction work site, but may also be a crane (low-floor type, gantry type, tower type) installed in a port or the like. Also, the work machine is not limited to a mobile crane, but may also be a fixed crane. Alternatively, the work machine may be an overhead crane or bridge crane with a movable part suspended above a runway. Moreover, the work machine may be a crane truck equipped with a crane, or a shovel with a crane function that applies a wire rope to the shovel attachment.

[0141] <Variation> Figure 14 is a schematic diagram showing an example of the configuration of the remote control system SYS for the crane 100 according to a modified example. As shown in Figure 14, the remote control system SYS is configured such that the crane 100, which is equipped with a remote control room RC, and the remote control room RC are connected to each other via a communication line NW so that they can communicate with each other.

[0142] The crane 100 transmits the detection results from various sensors installed on the crane 100 to the remote control room RC using a communication device T1 installed on the crane 100. Furthermore, the crane 100 transmits image information captured by an imaging device (not shown) to the remote control room RC.

[0143] The remote control room RC is equipped with a display device D1E, an operating device 42, an operating sensor 43, an operating seat DS, a remote controller 40, and a communication device T2.

[0144] The remote controller 40 includes an acquisition unit 301, an operation reception unit 302, a display control unit 303, a registration unit 304, a position recognition unit 305, a trajectory generation unit 306, and a control unit 307, which were provided in the controller 30 of the above-described embodiment. The control unit 307 generates control commands for controlling the crane 100 and transmits the generated control commands to the crane 100 using the communication device T2.

[0145] Therefore, the remote controller 40 can achieve semi-automatic control of the crane 100 using a simplified operation mode. Specifically, the remote controller 40 receives position information from the crane 100 indicating each position for moving the boom 6, and registers this position information in the storage device of the remote controller 40. This position information includes the position of the suspension support 6S, the position of the lower end of the wire rope 82, and the target position TP. The remote controller 40 can use the position information as a position for automatically controlling the upper slewing body 3 and the boom 6. The trajectory generation unit 306 can generate a target trajectory based on the position information. In addition, the display device D1E, under the control of the remote controller 40, displays the registered position information and target trajectory in a display area that represents the working space of the crane 100 in two-dimensional or three-dimensional coordinates.

[0146] Furthermore, when a slewing operation is performed by the operating device 42, the remote controller 40 transmits commands to the crane 100 for slewing control of the upper slewing body 3 and luffing control of the front attachment 7, so that the boom 6 moves to the target position TP along the target trajectory. As a result, the crane 100 moves the boom 6 and boom hook 81 (the lower end of the wire rope 82) to the target position TP. At this time, the crane 100 can suppress the swaying of the suspended load HL or boom hook 81 by performing the sway suppression control described above (including stop control, follow adjustment processing, etc.), thereby achieving stable movement.

[0147] In this way, by operating from the remote control room (RC), the crane 100 can be controlled even from a remote location. Therefore, even when the work site is in a remote location, it becomes easier to secure operators for the crane 100.

[0148] <Note> The technical concept and effects of this disclosure, as described in the embodiments above, are described below.

[0149] A first aspect of this disclosure is a working machine (crane 100) comprising a wire rope 82 having a lower end (boom hook 81) capable of holding a suspended load HL, and a movable suspension pivot 6S that suspends the wire rope 82, wherein when moving the lower end of the wire rope 82 horizontally from a set first position (starting position) to a second position (target position TP), the suspension pivot 6S is positioned ahead of the position of the lower end of the wire rope 82, and this state of the lower end of the wire rope 82 following is maintained from the first position to a position close to the second position.

[0150] As described above, the work machine (crane 100) can move the suspension support section 6S by controlling the movement of the wire rope 82, thereby suppressing the swaying of the lower end of the wire rope 82. This reduces the likelihood of the lower end of the wire rope 82 deviating significantly from the target trajectory of the suspension support section 6S during the movement control of the wire rope 82. For example, it becomes possible to avoid problems such as the suspended load HL held by the wire rope 82 interfering with an obstacle.

[0151] Furthermore, the working machine (crane 100) reduces the movement speed of the suspension support section 6S when it is close to the second position (target position TP), allowing the lower end of the wire rope 82 (boom hook 81), which is moving by inertia, to precede the suspension support section 6S. Subsequently, the suspension support section 6S is moved so that it vertically overlaps with the position of the lower end of the wire rope 82 that has preceded it. As a result, the working machine can effectively suppress the swaying of the lower end of the wire rope 82 even when the suspension support section 6S is stopped.

[0152] Furthermore, when the working machine (crane 100) moves the lower end of the wire rope 82 (boom hook 81) ahead of the suspension support section 6S, it controls the movement speed and position of the suspension support section 6S so that the limit position at which the lower end of the wire rope 82 swings due to inertia becomes the second position (target position TP). This makes it possible for the working machine to control its position so that the suspension support section 6S and the lower end of the wire rope 82 stop precisely at the target position TP.

[0153] Furthermore, while the working machine (crane 100) is controlling its movement from the first position (starting position) to a position close to the second position (target position TP), if the lower end of the wire rope 82 (boom hook 81) overtakes or is estimated to overtake the suspension support section 6S, the working machine increases the movement speed of the suspension support section 6S. This allows the working machine to return to a control that makes the lower end of the wire rope 82 follow the suspension support section 6S, even if the lower end of the wire rope 82 is ahead of the suspension support section 6S.

[0154] Furthermore, the work machine (crane 100) monitors the inclination angle θ of the wire rope 82 with respect to the vertical direction and determines or estimates that the lower end of the wire rope 82 (boom hook 81) has overtaken the suspension support point 6S based on the inclination angle θ. This allows the work machine to easily determine or estimate the state of the lower end of the wire rope 82.

[0155] Furthermore, the inclination angle θ of the wire rope 82 is calculated by obtaining the position of the suspension support point 6S and the position of the lower end of the wire rope 82 using the surrounding recognition device ES. This allows the work machine (crane 100) to easily obtain the inclination angle θ of the wire rope 82 and smoothly determine whether the lower end of the wire rope 82 is leading the suspension support point 6S.

[0156] Furthermore, the working machine is a crane 100 including a slewing body (upper slewing body 3) and a boom 6 that is luffably attached to the slewing body. The suspension fulcrum 6S is provided at the tip of the boom 6, and when the tip of the boom 6 is moved from a first position to a second position, the slewing control of the slewing body and the luffing control of the boom 6 are performed, while the suspension fulcrum 6S is positioned ahead of the position of the lower end of the wire rope 82, and the lower end of the wire rope 82 is kept following. As a result, the crane 100 can perform slewing control and luffing control while ensuring that the lower end of the wire rope 82 follows the suspension fulcrum 6S well.

[0157] The working machine (crane 100) according to the embodiments disclosed herein is illustrative in all respects and not restrictive. The embodiments can be modified and improved in various ways without departing from the scope and spirit of the appended claims. The features described in the above embodiments can be otherwise configured and combined in a non-consistent manner. [Explanation of symbols]

[0158] 3. Upper rotating body 6 Boom 6S Suspension pivot point 81 Boom Hook 82 Wire Rope 100 Cranes HL Hanging load TP target position

Claims

1. A wire rope having a lower end capable of holding a suspended load, A work machine comprising a suspension point that is movable and from which the wire rope is suspended, When moving the lower end of the wire rope horizontally from a set first position to a second position, the suspension pivot point is positioned ahead of the lower end of the wire rope, and this state of the lower end of the wire rope following is maintained from the first position to a position close to the second position. A type of machinery used for industrial work.

2. At a position close to the second position, the movement speed of the suspension support is reduced so that the lower end of the wire rope, which moves by inertia, precedes the suspension support. Subsequently, the suspension support point is moved so that it vertically overlaps with the position of the lower end of the preceding wire rope. The work machine according to claim 1.

3. When the lower end of the wire rope is brought ahead of the suspension support point, the movement speed and position of the suspension support point are controlled so that the limit position at which the lower end of the wire rope swings due to inertia becomes the second position. The working machine according to claim 2.

4. While controlling the movement from the first position to a position close to the second position, if the lower end of the wire rope overtakes or is estimated to overtake the suspension support point, the movement speed of the suspension support point is increased. A working machine according to any one of claims 1 to 3.

5. The angle of inclination of the wire rope with respect to the vertical is monitored, Based on the aforementioned inclination angle, it is determined or estimated that the lower end of the wire rope has overtaken the suspension support point. The work machine according to claim 4.

6. The inclination angle of the wire rope is calculated by obtaining the position of the suspension support point and the position of the lower end of the wire rope using the surrounding recognition device. The working machine according to claim 5.

7. The aforementioned work machine is a crane including a slewing body and a boom that is arrangable and movable to the slewing body, The aforementioned suspension support point is provided at the tip of the boom, When moving the tip of the boom from the first position to the second position, the rotational control of the slewing body and the luffing control of the boom are performed while the suspension support portion is positioned ahead of the position of the lower end of the wire rope, and the lower end of the wire rope is kept following. A working machine according to any one of claims 1 to 3.

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