Working machine

Abstract

This crane comprises a turning angular velocity setting unit (702). The turning angular velocity setting unit (702) sets, on the basis of the equation of motion for a suspended load in each of the turning direction and the radial direction, including at least the length of an undulating body, the length of a load suspending rope, and the undulation angle of the undulating body, the turning angular velocity of an upper body until a target position is reached to include a two-stage S-shaped trajectory in each of an acceleration range and a deceleration range, so that a radial-direction swing angle and a turning-direction swing angle at the target position are smaller than a predetermined threshold angle, and the time the suspended load takes to reach the target position becomes minimum.

Description

Working machinery

[0001] The present invention relates to a work machine capable of moving suspended loads.

[0002] Conventionally, cranes are known as working machines that consist of a lower traveling body, an upper slewing body supported by the lower traveling body so as to be able to slewing around a pivot axis extending vertically, and luffing elements such as a boom or jib. The luffing elements are attached to the front of the upper slewing body so as to be able to rotate in the luffing direction around a horizontal pivot axis. A hook is attached to a lifting rope that hangs down from the tip of the luffing elements, and the load is lifted when the load is connected to this hook. When the upper slewing body rotates with the load lifted in this state, the load can be moved in the direction of rotation.

[0003] Patent documents 1 and 2 disclose a technique for linearly controlling the trajectory of the crane's movement speed in order to reduce load swing that occurs when a suspended load is moved in an overhead crane installed in a building.

[0004] The technologies described in Patent Documents 1 and 2 relate to overhead cranes, and therefore the load swing of the suspended load considered occurs in a plane including the direction of crane movement and the vertical direction. On the other hand, in the slewing motion of a work machine, the suspended load swings in the slewing direction (circumferential direction) and radial direction. In particular, in the slewing motion of a work machine, three-dimensional behavior of the suspended load occurs, including Coriolis force and centrifugal force. For this reason, even if the technologies described in Patent Documents 1 and 2 are applied to a work machine, it is difficult to stably reduce the load swing of the suspended load that occurs in the slewing motion of the work machine.

[0005] JP 2021-38047 A JP 9-40362 A

[0006] The object of the present invention is to provide a work machine that can efficiently move a suspended load to a target position by a swivel motion, and suppress the swaying of the suspended load at the target position.

[0007] The present invention provides a work machine. The work machine comprises a lower body, an upper body, a luffing body, a load rope, a slewing drive unit, a luffing body length information acquisition unit, a slewing angle detection unit, a rope length information acquisition unit, a movement information receiving unit, a speed setting unit, and a command signal generation unit. The upper body is supported on the lower body so as to be rotatable around a slewing center axis extending in the vertical direction. The luffing body includes a base end of the luffing body and a tip end of the luffing body opposite to the base end, both supported on the upper body so as to be rotatable in the luffing direction around a horizontal rotation center axis. The load rope hangs down from the tip end of the luffing body and is connected to a load. The slewing drive unit receives a predetermined angular velocity command signal and can rotate the upper body around the slewing center axis at a speed corresponding to the angular velocity command signal. The luffing body length information acquisition unit acquires luffing body length information, which is information corresponding to the length of the luffing body in the longitudinal direction of the luffing body, which is the direction connecting the base end and the tip end of the luffing body. The rotation angle detection unit detects the rotation angle of the upper body around the rotation center axis. The luffing angle detection unit detects the luffing body's luffing angle around the rotation center axis. The rope length information acquisition unit acquires rope length information, which is information corresponding to the length of the load rope between the tip end of the luffing body and the suspended load. The movement information receiving unit receives movement information, including a target rotation angle, to move the suspended load to a predetermined target position around the rotation center axis by the rotational movement of the upper body, starting from the initial state in which the suspended load is lifted by the load rope. If the angle of the suspension rope with respect to the vertical direction when the raised body is viewed along the rotational direction of the upper body is defined as the radial swing angle, and the angle of the suspension rope with respect to the vertical direction when the raised body is viewed along the radial direction of the rotational movement of the upper body is defined as the rotational swing angle, then the speed setting unit sets the angular velocity of the upper body to reach the target position to include multiple curved trajectories in each of the acceleration and deceleration regions, based on the equations of motion of the suspension load for each of the rotational and radial directions, which include at least the length of the raised body, the length of the suspension rope, and the raised angle, such that the radial swing angle and the rotational swing angle at the target position are smaller than a predetermined threshold angle and the time it takes for the suspension load to reach the target position is minimized.The command signal generation unit generates and outputs the angular velocity command signal corresponding to the angular velocity set by the speed setting unit.

[0008] According to this configuration, the speed setting unit can set the angular velocity of the upper body based on the equation of motion of the suspended load, such that the swing angle of the suspended load at the target position is smaller than the threshold angle and the time it takes for the suspended load to reach the target position is minimized. In particular, since the trajectory of the slewing angular velocity is set to include multiple curved trajectories in both the acceleration and deceleration zones, the suspended load can be moved with the minimum possible travel time while suppressing the swing at the target position.

[0009] Figure 1 is a side view of a work machine according to one embodiment of the present invention. Figure 2 is a schematic perspective view for explaining the slewing control of a work machine according to one embodiment of the present invention. Figure 3 is a block diagram of a work machine according to one embodiment of the present invention. Figure 4 is a flowchart of the slewing control of a work machine according to one embodiment of the present invention. Figure 5 is a perspective view of an experimental apparatus assuming a work machine according to one embodiment of the present invention. Figure 6 is a block diagram of an experimental apparatus assuming a work machine according to one embodiment of the present invention. Figure 7 is an example of a slewing speed profile used in a verification experiment, which is compared with the slewing speed profile of the upper body according to one embodiment of the present invention. Figure 8 is an example of a slewing speed profile used in a verification experiment, which is compared with the slewing speed profile of the upper body according to one embodiment of the present invention. Figure 9A is a graph showing the time progression of the slewing angle in the verification experiment of the present invention. Figure 9B is a graph showing the time progression of the slewing angular velocity in the verification experiment of the present invention. Figure 9C is a graph showing the time progression of the slewing angular acceleration in the verification experiment of the present invention. Figure 9D is a graph showing the time progression of the suspended load swing in the verification experiment of the present invention. Figure 10A is a graph showing the time progression of the slewing angle in the verification experiment of the present invention. Figure 10B is a graph showing the time course of the slewing angular velocity in the verification experiment of the present invention. Figure 10C is a graph showing the time course of the slewing angular acceleration in the verification experiment of the present invention. Figure 10D is a graph showing the time course of the suspended load swing in the verification experiment of the present invention. Figure 11 is an example of the slewing velocity profile of the upper body in an embodiment of the present invention. Figure 12 is an example of the slewing velocity profile of the upper body in an embodiment of the present invention. Figure 13A is a graph showing the time course of the slewing angle in an embodiment of the present invention. Figure 13B is a graph showing the time course of the slewing angular velocity in an embodiment of the present invention. Figure 13C is a graph showing the time course of the slewing angular acceleration in an embodiment of the present invention. Figure 13D is a graph showing the time course of the suspended load swing in an embodiment of the present invention. Figure 14A is a graph showing the time course of the slewing angle in an embodiment of the present invention. Figure 14B is a graph showing the time course of the slewing angular velocity in an embodiment of the present invention. Figure 14C is a graph showing the time course of the slewing angular acceleration in an embodiment of the present invention.Figure 14D is a graph showing the time progression of the suspended load swing in an embodiment of the present invention. Figure 15A is a graph showing the time progression of the slewing angle in an embodiment of the present invention. Figure 15B is a graph showing the time progression of the slewing angular velocity in an embodiment of the present invention. Figure 15C is a graph showing the time progression of the slewing angular acceleration in an embodiment of the present invention. Figure 15D is a graph showing the time progression of the suspended load swing in an embodiment of the present invention. Figure 16A is a graph showing the time progression of the slewing angle in an embodiment of the present invention. Figure 16B is a graph showing the time progression of the slewing angular velocity in an embodiment of the present invention. Figure 16C is a graph showing the time progression of the slewing angular acceleration in an embodiment of the present invention. Figure 16D is a graph showing the time progression of the suspended load swing in an embodiment of the present invention. Figure 17A is a graph showing the time progression of the slewing angle in an embodiment of the present invention. Figure 17B is a graph showing the time progression of the slewing angular velocity in an embodiment of the present invention. Figure 17C is a graph showing the time progression of the slewing angular acceleration in an embodiment of the present invention. Figure 17D is a graph showing the time progression of the suspended load swing in an embodiment of the present invention. Figure 18A is a graph showing the time progression of the slewing angle in an embodiment of the present invention. Figure 18B is a graph showing the time progression of the slewing angular velocity in an embodiment of the present invention. Figure 18C is a graph showing the time progression of the slewing angular acceleration in an embodiment of the present invention. Figure 18D is a graph showing the time progression of the suspended load swing in an embodiment of the present invention. Figure 19A is a graph showing the time progression of the slewing angle in an embodiment of the present invention. Figure 19B is a graph showing the time progression of the slewing angular velocity in an embodiment of the present invention. Figure 19C is a graph showing the time progression of the slewing angular acceleration in an embodiment of the present invention. Figure 19D is a graph showing the time progression of the suspended load swing in an embodiment of the present invention. Figure 20A is a graph showing the time progression of the slewing angle in an embodiment of the present invention. Figure 20B is a graph showing the time progression of the slewing angular velocity in an embodiment of the present invention. Figure 20C is a graph showing the time progression of the slewing angular acceleration in an embodiment of the present invention. Figure 20D is a graph showing the time progression of the suspended load swing in an embodiment of the present invention. Figure 21A is a graph showing the time progression of the slewing angle in an embodiment of the present invention. Figure 21B is a graph showing the time course of the turning angular velocity in an embodiment of the present invention.Figure 21C is a graph showing the time course of the slewing angular acceleration in an embodiment of the present invention. Figure 21D is a graph showing the time course of the suspended load swing in an embodiment of the present invention. Figure 22A is a graph showing the time course of the slewing angle in an embodiment of the present invention. Figure 22B is a graph showing the time course of the slewing angular velocity in an embodiment of the present invention. Figure 22C is a graph showing the time course of the slewing angular acceleration in an embodiment of the present invention. Figure 22D is a graph showing the time course of the suspended load swing in an embodiment of the present invention. Figure 23A is a graph showing the time course of the slewing angular velocity and suspended load swing in an embodiment of the present invention. Figure 23B is a graph showing the time course of the slewing angular velocity and suspended load swing in an embodiment of the present invention. Figure 24 is a diagram showing the attachment positions of strain gauges on the lower boom in an embodiment of the present invention. Figure 25 is a graph showing the time course of measured stress, suspended load swing, and slewing angle in an embodiment of the present invention. Figure 26 is a diagram showing an overview of the dynamic simulation model in an embodiment of the present invention, and is a perspective view of the crane model. Figure 27 is a diagram showing an overview of a dynamic simulation model in an embodiment of the present invention, and is a side view of the crane model. Figure 28 is a graph showing the time evolution of the slewing angular velocity trajectory and slewing angle under the operation of a skilled operator in an embodiment of the present invention. Figure 29 is a graph showing the time evolution of measured stress, load swing, and slewing angle, corresponding to Figure 28 in an embodiment of the present invention. Figure 30 is a graph showing parts of Figures 28 and 29 superimposed in an embodiment of the present invention. Figure 31 is a graph showing a general input trajectory referenced in an embodiment of the present invention, and is a graph showing the time evolution of acceleration and velocity during slewing. Figure 32 is a perspective view showing the stress evaluation location of the FEM simulation in an embodiment of the present invention. Figure 33 is a graph showing the simulation results for each operating condition in an embodiment of the present invention, and is a graph showing the time evolution of the generated stress. Figure 34 is a diagram showing a three-stage S-shaped trajectory in an embodiment of the present invention, and is a graph showing the time evolution of the slewing angular velocity. Figure 35 is a block diagram for generating the optimal trajectory in an embodiment of the present invention. Figure 36A is a graph showing the time changes of the slewing angle, boom angle, and rope length in an embodiment of the present invention.Figure 36B is a graph showing the time evolution of slewing angular velocity, boom angular velocity, and rope length velocity in an embodiment of the present invention. Figure 36C is a graph showing the time evolution of slewing angular acceleration, boom angular acceleration, and rope length acceleration in an embodiment of the present invention. Figure 36D is a graph showing the time evolution of the suspended load swing angle in an embodiment of the present invention. Figure 37A is a graph showing the time evolution of slewing angle, boom angle, and rope length in an embodiment of the present invention. Figure 37B is a graph showing the time evolution of slewing angular velocity, boom angular velocity, and rope length velocity in an embodiment of the present invention. Figure 37C is a graph showing the time evolution of slewing angular acceleration, boom angular acceleration, and rope length acceleration in an embodiment of the present invention. Figure 37D is a graph showing the time evolution of the suspended load swing angle in an embodiment of the present invention. Figure 38A is a graph showing the time evolution of slewing angle, boom angle, and rope length in an embodiment of the present invention. Figure 38B is a graph showing the time evolution of slewing angular velocity, boom angular velocity, and rope length velocity in an embodiment of the present invention. Figure 38C is a graph showing the time progression of rotational angular acceleration, boom angular acceleration, and rope length acceleration in an embodiment of the present invention. Figure 38D is a graph showing the time progression of the suspended load swing angle in an embodiment of the present invention. Figure 39A is a graph showing the time progression of rotational angle, boom angle, and rope length in an embodiment of the present invention. Figure 39B is a graph showing the time progression of rotational angular velocity, boom angular velocity, and rope length velocity in an embodiment of the present invention. Figure 39C is a graph showing the time progression of rotational angular acceleration, boom angular acceleration, and rope length acceleration in an embodiment of the present invention. Figure 39D is a graph showing the time progression of the suspended load swing angle in an embodiment of the present invention. Figure 40 is a graph showing the operation time and load swing amount (angle) for each condition of the three-stage S-shaped trajectory, STT trajectory, and skilled operator trajectory, with the results for the two-stage S-shaped trajectory as a reference. Figure 41 is a graph showing the boom luffing angular velocity trajectory and rope vertical velocity trajectory proposed in this embodiment along with the three-stage S-shaped trajectory of rotational movement. Figure 42 is a plan view showing the boom tip trajectory of the proposed trajectory that combines slewing and boom luffing movements. Figure 43A is a graph showing the time changes of slewing angle, boom angle, and rope length in an embodiment of the present invention.Figure 43B is a graph showing the time course of the slewing angular velocity, boom angular velocity, and rope length velocity in an embodiment of the present invention. Figure 43C is a graph showing the time course of the slewing angular acceleration, boom angular acceleration, and rope length acceleration in an embodiment of the present invention. Figure 43D is a graph showing the time course of the suspended load swing angle in an embodiment of the present invention. Figure 44A is a graph showing the time course of the slewing angle, boom angle, and rope length in an embodiment of the present invention. Figure 44B is a graph showing the time course of the slewing angular velocity, boom angular velocity, and rope length velocity in an embodiment of the present invention. Figure 44C is a graph showing the time course of the slewing angular acceleration, boom angular acceleration, and rope length acceleration in an embodiment of the present invention. Figure 44D is a graph showing the time course of the suspended load swing angle in an embodiment of the present invention. Figure 45A is a graph showing the time course of the slewing angle, boom angle, and rope length in an embodiment of the present invention. Figure 45B is a graph showing the time course of the slewing angular velocity, boom angular velocity, and rope length velocity in an embodiment of the present invention. Figure 45C is a graph showing the time progression of rotational angular acceleration, boom angular acceleration, and rope length acceleration in an embodiment of the present invention. Figure 45D is a graph showing the time progression of the suspended load swing angle in an embodiment of the present invention. Figure 46A is a graph showing the time progression of rotational angle, boom angle, and rope length in an embodiment of the present invention. Figure 46B is a graph showing the time progression of rotational angular velocity, boom angular velocity, and rope length velocity in an embodiment of the present invention. Figure 46C is a graph showing the time progression of rotational angular acceleration, boom angular acceleration, and rope length acceleration in an embodiment of the present invention. Figure 46D is a graph showing the time progression of the suspended load swing angle in an embodiment of the present invention. Figure 47A is a graph showing the time progression of rotational angle, boom angle, and rope length in an embodiment of the present invention. Figure 47B is a graph showing the time progression of rotational angular velocity, boom angular velocity, and rope length velocity in an embodiment of the present invention. Figure 47C is a graph showing the time progression of rotational angular acceleration, boom angular acceleration, and rope length acceleration in an embodiment of the present invention. Figure 47D is a graph showing the time progression of the suspended load swing angle in an embodiment of the present invention. Figure 48A is a graph showing the time changes of the slewing angle, boom angle, and rope length in an embodiment of the present invention.Figure 48B is a graph showing the time course of the slewing angular velocity, boom angular velocity, and rope length velocity in an embodiment of the present invention. Figure 48C is a graph showing the time course of the slewing angular acceleration, boom angular acceleration, and rope length acceleration in an embodiment of the present invention. Figure 48D is a graph showing the time course of the suspended load swing angle in an embodiment of the present invention. Figure 49A is a graph showing the time course of the slewing angle, boom angle, and rope length in an embodiment of the present invention. Figure 49B is a graph showing the time course of the slewing angular velocity, boom angular velocity, and rope length velocity in an embodiment of the present invention. Figure 49C is a graph showing the time course of the slewing angular acceleration, boom angular acceleration, and rope length acceleration in an embodiment of the present invention. Figure 49D is a graph showing the time course of the suspended load swing angle in an embodiment of the present invention. Figure 50A is a graph showing the relationship between the suspended load swing angle and stress amplitude in an embodiment of the present invention. Figure 50B is a graph showing the relationship between the suspended load swing angle and stress amplitude in an embodiment of the present invention. Figure 50C is a graph showing the relationship between the suspended load swing angle and stress amplitude in an embodiment of the present invention. Figure 51 is a graph comparing the stresses applied to the lower booms of multiple tracks in an embodiment of the present invention. Figure 52A is a diagram showing the load profile of the assumed operation in the fatigue evaluation method in an embodiment of the present invention. Figure 52B is a diagram showing the load profile of the assumed operation in the fatigue evaluation method in an embodiment of the present invention.

[0010] <First Embodiment> An embodiment of the present invention will be described below with reference to the drawings. Figure 1 is a side view of the crane 10 (an example of a work machine) according to this embodiment. Although Figure 1 shows the directions of "up," "down," "forward," and "backward," these directions are shown for convenience in order to explain the structure of the crane 10 according to this embodiment and the rotation control described later, and do not limit the direction of movement or usage of the work machine according to the present invention.

[0011] The crane 10 comprises a traveling body 14 (lower body), a slewing body 12 (upper body) supported on the traveling body 14 so as to be able to rotatably around a pivot axis extending vertically, a boom 16 (luffing body), and a mast 20. A counterweight 13 for adjusting the balance of the crane 10 is mounted on the rear of the slewing body 12. A cab 15 is provided at the front end of the slewing body 12. The cab 15 corresponds to the operator's seat of the crane 10.

[0012] The boom 16 shown in Figure 1 is a so-called lattice type and consists of a lower boom 16A (base end of the luffing body), one or more (three in the illustrated example) intermediate booms 16B, 16C, and 16D, and an upper boom 16E (tip end of the luffing body opposite to the base end of the luffing body). Specifically, the lower boom 16A is supported at the front of the slewing body 12 so as to be rotatable in the luffing direction around a horizontal rotation axis (first rotation axis). The intermediate booms 16B, 16C, and 16D are detachably added to the tip end of the lower boom 16A in that order. The upper boom 16E is detachably added to the tip end of the intermediate boom 16D. The lower boom 16A is rotatably pivotally supported on the slewing body 12 at a boom foot pin 16S provided at its lower end.

[0013] Furthermore, the boom 16 has idler sieves 34S and 36S. The idler sieves 34S and 36S are rotatably supported on the rear side of the lower boom 16A, respectively.

[0014] However, the specific structure of the boom is not limited in this invention. For example, the boom may have no intermediate members, or it may have a different number of intermediate members than described above. Furthermore, the boom may be composed of a single member.

[0015] The mast 20 has a base end and a pivot end, the base end of which is rotatably connected to the slewing body 12. The pivot axis of the mast 20 is parallel to the pivot axis of the boom 16 and is located immediately behind the pivot axis of the boom 16. In other words, the mast 20 is rotatable in the same direction as the luffing direction of the boom 16.

[0016] Furthermore, the crane 10 includes a pair of left and right boom backstops 23 and a pair of left and right boom guy lines 24.

[0017] A pair of left and right boom backstops 23 are provided on both the left and right sides of the lower boom 16A of the boom 16. These boom backstops 23 come into contact with the center of the slewing body 12 in the front-rear direction when the boom 16 reaches the upright position shown in Figure 1. This contact prevents the boom 16 from being blown backward by strong winds or the like.

[0018] A pair of boom guy lines 24 connect the rotating end of the mast 20 to the tip of the boom 16. This connection synchronizes the rotation of the mast 20 with the rotation of the boom 16.

[0019] Furthermore, the crane 10 is equipped with various winches. Specifically, the crane 10 is equipped with a boom luffing winch 30 for luffing the boom 16, and a main hoisting winch 34 and an auxiliary hoisting winch 36 for hoisting and lowering the suspended load. The crane 10 is also equipped with a boom luffing rope 38, a main hoisting rope 50 (suspending load rope) that hangs down from the tip of the boom 16 and is connected to the suspended load, and an auxiliary hoisting rope 60. In the crane 10 according to this embodiment, the main hoisting winch 34 and the auxiliary hoisting winch 36 are installed near the base end of the boom 16. The boom luffing winch 30 is also installed on the slewing body 12. The positions of these winches 30, 34, and 36 are not limited to those described above.

[0020] The boom luffing winch 30 winds in and unwinds the boom luffing rope 38. The boom luffing rope 38 is routed so that the mast 20 rotates as the winch winds in and unwinds. Specifically, sheave blocks 40 and 42, each with multiple sheaves arranged in the width direction, are provided at the rotating end of the mast 20 and the rear end of the slewing body 12, respectively, and the boom luffing rope 38 pulled out from the boom luffing winch 30 is stretched between the sheave blocks 40 and 42. Therefore, as the boom luffing winch 30 winds in and unwinds the boom luffing rope 38, the distance between the two sheave blocks 40 and 42 changes, causing the mast 20 and the boom 16, which is linked to it, to rotate in the luffing direction.

[0021] The main hoisting winch 34 raises and lowers the load using the main hoisting rope 50. The main hoisting rope 50 (load rope) hangs down from the tip of the boom 16 and is connected to the load. A main hoisting guide sheave 54 is positioned at the tip of the boom 16, and a main hoisting sheave block is provided adjacent to the main hoisting guide sheave 54, with a plurality of main hoisting point sheaves 56 arranged in the width direction. The main hoisting rope 50 pulled out from the main hoisting winch 34 is sequentially placed over the idler sheave 34S and the main hoisting guide sheave 54, and is also stretched between the main hoisting point sheave 56 of the sheave block and the sheave 58 of the sheave block provided on the main hook 57 for the load. Therefore, when the main hoisting winch 34 winds up or unwinds the main hoisting rope 50, the distance between the two sheaves 56 and 58 changes, causing the main hook 57, which is connected to the main hoisting rope 50 hanging down from the tip of the boom 16, to be raised or lowered. As a result, the suspended load can be raised or lowered.

[0022] Similarly, the auxiliary winch 36 raises and lowers the load using the auxiliary rope 60. For this auxiliary winding, an auxiliary guide sheave 64 is rotatably mounted coaxially with the main guide sheave 54, and an auxiliary point sheave (not shown) is rotatably mounted adjacent to the auxiliary guide sheave 64. The auxiliary rope 60 pulled out from the auxiliary winch 36 is sequentially placed over the idler sheave 36S and the auxiliary guide sheave 64, and is also suspended from the auxiliary point sheave. Therefore, when the auxiliary winch 36 winds up or unwinds the auxiliary rope 60, an auxiliary hook for lifting a load (not shown) connected to the end of the auxiliary rope 60 is raised or lowered.

[0023] Figure 2 is a schematic perspective view illustrating the rotation control of the crane 10 according to this embodiment. Figure 3 is a block diagram of the crane 10 according to this embodiment.

[0024] In Figure 2, the pivot axis of the slewing body 12 is defined as the Z-axis, and the X-axis and Y-axis are provided on the upper surface of the slewing body 12. Also, a is the distance between the base end (rotation center) of the boom 16 and the pivot center of the slewing body 12, i.e., the boom offset distance. Note that the base end of the boom 16 may be located on the pivot axis of the slewing body 12. In Figure 2, L is the length of the boom 16, and l (lowercase L) is the length of the main hoisting rope 50 hanging from the tip of the boom 16 to the suspended load LM (rope length). Also, angle θ １ and θ ２ This indicates the load swing angle (load swing angle) of the suspended load LM (main hook 57). Specifically, the angle θ １ This is the angle of the main hoisting rope 50 with respect to the vertical when the boom 16 is viewed along the rotational direction of the slewing body 12, and is the radial swing angle θ. １ This is called (the angle of deviation in the normal plane). On the other hand, angle θ ２ This is the angle of the main hoisting rope 50 relative to the vertical when the boom 16 is viewed along the radial direction of the rotational movement of the slewing body 12, and is the slewing direction swing angle θ. ２ This is referred to as the (angle of swing at the tangential plane). Note that the radial swing angle θ may vary depending on the swing motion of the suspended load LM. １ and the rotational direction deflection angle θ ２takes not only positive values but also negative values.

[0025] Angle θ ３ is the heaving angle around the rotation center axis of the boom 16. In FIG. 2, the angle θ ３ is defined with respect to the vertical direction, but it may also be defined with respect to the horizontal direction. The angle θ ４ is the turning angle around the turning center axis of the revolving body 12. When the revolving body 12 turns in the turning direction, the angle θ ４ changes. At this time, the boom 16 supported by the revolving body 12 also turns in the same way, and swing occurs in the suspended load LM (main hoist rope 50).

[0026] Also, in the coordinate system of FIG. 2, with the base end of the boom 16 as the origin, a predetermined horizontal direction (for example, the forward direction of the traveling body 14, the forward direction of the revolving body 12 at the start of turning) is the X-axis, a horizontal direction orthogonal to the X-axis is the Y-axis, and a direction (vertical direction) orthogonal to the X-axis and the Y-axis respectively is the Z-axis. Also, in FIG. 2, the mass m of the suspended load LM is shown.

[0027] In the present embodiment, as shown in FIG. 2, when the suspended load LM suspended from the tip of the boom 16 (heaving body) is swung by the turning operation (change in turning angle θ ４ of the revolving body 12), it is possible to move the suspended load LM to the target position as quickly as possible while suppressing the swing of the suspended load LM at the target position.

[0028] Referring to FIG. 3, the crane 10 further includes a control unit 70, a turning drive unit 71, a boom drive unit 72, a winch drive unit 73, a turning operation unit 74, a boom operation unit 75, a winch operation unit 76, an input unit 81 (movement information receiving unit), a turning angle detection unit 82, a heaving angle detection unit 83, a rope length detection unit 84 (rope length information acquisition unit), a boom length acquisition unit 85 (heaving body length information acquisition unit), a suspended load weight detection unit 86, and a display unit 87.

[0029] The slewing drive unit 71 receives a predetermined angular velocity command signal and is capable of swiveling the slewing body 12 around the pivot axis at a speed (angular velocity) corresponding to the angular velocity command signal. Specifically, the slewing drive unit 71 generates a driving force that enables the slewing body 12 to slewing in a first slewing direction and in a second slewing direction opposite to the first slewing direction around the pivot axis. The slewing drive unit 71 includes a hydraulic slewing motor and control valve that slewing the slewing body 12 by receiving a supply of hydraulic fluid.

[0030] The boom drive unit 72 generates a driving force to rotate the boom luffing winch 30, enabling the boom 16 to rotate (luff) around the rotational axis. The boom drive unit 72 includes a hydraulic luffing motor and control valve that rotate the boom luffing winch 30 by receiving a supply of hydraulic fluid.

[0031] The winch drive unit 73 generates a driving force to rotate the main hoisting winch 34, and by winding and unwinding the main hoisting rope 50 using the main hoisting winch 34, the suspended load LM can be raised and lowered relative to the ground. The winch drive unit 73 includes a hydraulic load motor and control valve that rotate the main hoisting winch 34 by receiving a supply of hydraulic fluid. A similar winch drive unit (not shown) for rotating the auxiliary hoisting winch 36 is also provided.

[0032] The slewing control unit 74, the boom control unit 75, and the winch control unit 76 are located inside the cab 15 and receive operations from the operator to drive each component of the crane 10. Each control unit has, for example, a tiltable lever structure.

[0033] The swivel operation unit 74 receives operations for driving the swivel body 12 to swivel using the swivel drive unit 71. The swivel operation unit 74 is switchable between a swivel position for swiveling the swivel body 12 in the first swivel direction and the second swivel direction, respectively, and a neutral position for stopping the swivel of the swivel body 12.

[0034] The boom operating unit 75 receives commands from the boom drive unit 72 to raise and lower the boom 16. The boom operating unit 75 is switchable between a luffing position for raising and lowering the boom 16 and a neutral position for stopping the luffing of the boom 16. In the luffing position, it is possible to operate the boom 16 in the raising direction to raise it and in the lowering direction to lower the boom 16.

[0035] The winch operating unit 76 receives operations from the winch drive unit 73 to raise and lower the suspended load LM. The winch operating unit 76 is switchable between a lifting position for raising and lowering the suspended load LM and a neutral position for stopping the lifting and lowering of the suspended load LM. In the lifting position, it is possible to operate the suspended load LM in the upward direction to raise it and in the downward direction to lower it.

[0036] The input unit 81 is located inside the cab 15 and receives input from the operator regarding the control of the crane 10. For example, the input unit 81 includes a touch panel input device, various switches, buttons, etc. The input unit 81 starts from the initial state in which the suspended load LM is lifted by the main hoisting rope 50 and sets a target slewing angle θ to move the suspended load LM to a predetermined target position around the slewing center axis by the slewing movement of the slewing body 12. ４ｄ We accept travel information that includes this information.

[0037] The rotation angle detection unit 82 detects the rotation angle θ of the rotating body 12 (boom 16) around the rotation center axis. ４ The rotation angle detection unit 82 includes a gyro sensor (IMU (Internal Measurement Unit) sensor) and a calculation unit (not shown). The rotation angle detection unit 82 detects and outputs the rotation angular velocity θ of the rotation center axis of the rotating body 12. ４ The gyro sensor measures the angular velocity, and the calculation unit converts the measured angular velocity into an angle by integrating it once with respect to time, and this angle is the rotation angle θ ４ The output is as follows. Note that the structure of the rotation angle detection unit 82 is not limited to the above, and known angle meters, encoders, etc. may also be used. Note that the rotation angular velocity θ changes over time. ４ By differentiating ', we obtain the rotational acceleration θ. ４'' is obtained.

[0038] The elevation angle detection unit 83 detects the elevation angle θ of the boom 16 around the rotation center axis. ３ The system detects and outputs the following. The elevation angle detection unit 83 consists of an inclination sensor and detects the relative angle of the boom 16 with respect to the vertical direction. The elevation angle detection unit 83 may also detect the relative angle with respect to other objects. For example, the elevation angle detection unit 83 detects the angle of the boom 16 to the ground (relative angle with respect to the horizontal direction) and subtracts this angle from 90 degrees to obtain the above-mentioned elevation angle θ. ３ The θ may be calculated and output. The elevation angle detection unit 83 may also be a known angle meter or the like. Note that the elevation angle θ changes over time. ３ By differentiating each of these terms once and twice, we can obtain the rate of change of the elevation angle θ. ３ , change in elevation angle acceleration θ ３ '' is obtained.

[0039] The rope length detection unit 84 acquires and outputs rope length information, which is information corresponding to the length l (lowercase L) of the main winding rope 50 between the tip of the boom 16 and the suspended load LM. In this embodiment, the distance between the main winding point sheave 56 and the main hook 57 (sheave 58) at the tip of the boom 16 is detected as the rope length. The rope length detection unit 84 includes a rotation amount detection unit capable of detecting the amount of rotation of the main winding winch 34, and a winding layer detection unit that detects the number of winding layers of the main winding rope 50 on the outer circumferential surface of the main winding winch 34. The rope length detection unit 84 calculates and outputs the distance based on the winch diameter of the main winding winch 34, the amount of winch rotation detected by the rotation amount detection unit, the amount of main winding rope 50 unwound from the main winding winch 34 estimated from the winding layers of the main winding rope 50 detected by the winding layer detection unit, and the number of times the main winding rope 50 is multiplied between the main winding point sheave 56 and the sheave block of the sheave 58. The rate of change of the rope length l, which changes over time, can be obtained by differentiating the rope length l once.

[0040] The method for detecting the length l of the main hoisting rope 50 is not limited to the above-described embodiment. For example, the rope length may be detected by clamping the wire with a sheave (not shown) and measuring the rotation of the sheave with an encoder. Alternatively, the suspended load LM may be detected by measuring the area below the tip of the boom 16 (boom top) in real time using a 3D LiDAR, and the rope length may be determined by measuring the distance from the boom top to the suspended load LM. Furthermore, the rope length may be calculated by measuring the distance to the suspended load LM using a known stereo camera or sound waves. In this case, the reference point for distance measurement may be any part of the boom, such as the boom top, the crane body, or the ground other than the crane. In addition, the rope length may be calculated by attaching a position-measuring sensor such as a GPS to the suspended load LM or the main hook 57.

[0041] The boom length acquisition unit 85 acquires information regarding the length L of the boom 16 used in the slewing control of the slewing body 12 performed by the control unit 70. That is, the boom length acquisition unit 85 acquires and outputs information (luffing body length information) corresponding to the length of the boom 16 in the longitudinal direction of the boom (luffing body longitudinal direction), which is the direction connecting the base end (luffing body base end) and the tip end (luffing body tip) of the boom 16. The boom length acquisition unit 85 may be a storage unit that stores the length of the boom 16 when the crane 10 is manufactured, or it may be an input unit that receives information regarding the length of the boom 16 from the operator. For this reason, the function of the boom length acquisition unit 85 may be performed by the storage unit 704 or input unit 81 of the control unit 70 in Figure 3. Furthermore, when multiple booms 16 of different lengths are selectively attached to the slewing body 12, the boom length acquisition unit 85 may also be a receiving unit that receives information regarding the length of the boom 16 from RFID or the like attached to each boom 16.

[0042] The suspended load detection unit 86 acquires and outputs information (suspended load amount information) regarding the weight (mass m) of the suspended load LM connected to the main hook 57. In this embodiment, the suspended load detection unit 86 includes a load sensor (load cell) (not shown) connected to the main winding rope 50, and detects the weight of the suspended load LM based on the change in the strain of the tension of the main winding rope 50. In other embodiments, the pressure in the hydraulic circuit that raises and lowers the boom 16 may be detected by a pressure gauge (not shown), and the load of the suspended load LM may be estimated based on this pressure.

[0043] The display unit 87 is a display located inside the cab 15 and displays various information to inform the operator.

[0044] The control unit 70 consists of a CPU (Central Processing Unit), a ROM (Read Only Memory) for storing control programs, and a RAM (Random Access Memory) used as a working area for the CPU. The control unit 70 functions by having the CPU execute the control program stored in the ROM, thereby comprising a drive control unit 701, a target speed calculation unit 702 (turning angle speed setting unit, speed setting unit), a command signal generation unit 703, and a storage unit 704.

[0045] The drive control unit 701 inputs command signals corresponding to the operating direction and amount of operation received by the slewing operation unit 74, boom operation unit 75, and winch operation unit 76 to the slewing drive unit 71, boom drive unit 72, and winch drive unit 73, respectively, and drives each drive unit.

[0046] The target velocity calculation unit 702 calculates the target velocity (target angular velocity θ) of the slewing body 12 until the suspended load LM reaches the target position when automatic slewing control is performed. ４ The ') is set. The automatic slewing control is a control that automatically moves the suspended load LM from a predetermined initial position to a target position in the slewing direction. In this case, regardless of the amount of operation received by the operation unit, the angular velocity set by the target velocity calculation unit 702 takes precedence. The target velocity calculation unit 702 similarly controls the velocity related to the change in the elevation angle of the boom 16 and the length of the main hoisting rope 50.

[0047] The command signal generation unit 703 generates and outputs an angular velocity command signal corresponding to the target velocity (angular velocity) set by the target velocity calculation unit 702. The angular velocity command signal output by the command signal generation unit 703 is input to the slewing drive unit 71. As a result, the slewing operation of the slewing body 12 is automatically controlled. In other embodiments, the angular velocity command signal may be input to and displayed on the display unit 87, and the operator may operate the slewing operation unit 74 according to the magnitude and direction of the angular velocity command signal (slewing assist). Similarly, the command signal generation unit 703 generates and outputs an angular velocity command signal corresponding to the target velocity set by the target velocity calculation unit 702, and inputs it to the boom drive unit 72 and the winch drive unit 73.

[0048] The memory unit 704 stores parameters, thresholds, and other information that are referenced during various control operations performed in the crane 10.

[0049] <Flowchart of Swivel Control> Figure 4 is a flowchart of the slewing control of the crane 10 according to this embodiment. When the control unit 70 performs automatic control of the slewing motion, first the control unit 70 determines whether the automatic control switch included in the input unit 81 is ON or OFF (step S1). If the automatic control switch is ON (YES in step S1), the control unit 70 determines whether movement information is stored in the storage unit 704 (step S2). As described above, the movement information is the target slewing angle θ to the target position to which the suspended load LM is moved. ４ｄ This includes the above, and is stored in the memory unit 704 when the operator inputs it through the input unit 81. However, the start conditions for turning control are not limited to those described above.

[0050] If there is movement information in step S2 (YES in step S2), the rotation angle detection unit 82, the elevation angle detection unit 83, and the rope length detection unit 84 will respectively determine the current rotation angle θ. ４ , relief angle θ ３The length l of the main winding rope 50 is detected (step S3). The detected information is stored in the storage unit 704. If the automatic control switch is OFF in step S1 (NO in step S1), or if there is no movement information in step S2 (NO in step S2), the processes of steps S1 and S2 in Figure 4 are repeated.

[0051] In step S3, once the information is detected, the boom length acquisition unit 85 acquires the length (L) of the boom 16. As mentioned above, the length of the boom 16 may be stored in the storage unit 704 beforehand, or it may be input through the input unit 81 or the like.

[0052] Next, the target speed calculation unit 702 calculates the rotational speed (rotational angular velocity θ) of the rotating body 12 as the suspended load LM moves from the initial position to the target position. ４ The profile (transition, trajectory) of ') is calculated (step S5). That is, in this embodiment, in order to suppress the swing of the suspended load LM, the slewing angle θ of the slewing body 12 is calculated. ４ The angular velocity θ depends on the (turning position). ４ It is controlled so that ' changes. In this explanation, the derivative of angle θ (angular velocity) is sometimes represented as θ', and the second derivative of θ (angular acceleration) is sometimes represented as θ''. Alternatively, the derivative may be represented by the number of dots (points) placed above θ. These notation rules are the same for other variables as well. Calculated rotational angular velocity θ ４ The progress of ' is displayed on the display unit 87, which the operator can check.

[0053] In step S5, the velocity profile (angular velocity θ) ４ Once the transition of ' is determined, in step S6, the target velocity calculation unit 702 calculates the estimated load swing amount of the suspended load LM at the target position. At this time, the radial swing angle θ of the suspended load LM is calculated from the equation of motion which will be described in detail later. １ and the rotational direction deflection angle θ ２ Each of these is calculated, and the results are displayed on the display unit 87. Note that the process in step S6 is not mandatory.

[0054] Next, the command signal generation unit 703 outputs the calculated angular velocity θ. ４A speed command signal (angular velocity command signal) corresponding to the value is generated (step S7) and input to the slewing drive unit 71. As a result, the slewing drive unit 71 rotates the slewing body 12, and automatic control of the slewing motion of the slewing body 12 is performed (step S8). At this time, as will be shown later, the command signal generation unit 703 may also issue commands regarding the luffing of the boom 16 and the raising and lowering of the main hoisting rope 50.

[0055] <Regarding the calculation of turning speed> Next, the turning speed (angular velocity θ) executed in step S5 above is calculated ４ The calculation of the trajectory (profile) of ')' will be described in detail.

[0056] As the slewing body 12 rotates toward the target position from the initial position where the suspended load LM is lifted by the boom 16, the suspended load LM connected to the main hoisting rope 50 experiences two-dimensional load swing in both the radial and slewing directions. Furthermore, as described later, if the boom 16 is raised or lowered, or if the length of the main hoisting rope 50 changes during the slewing motion, the load swing of the suspended load LM becomes more complex.

[0057] Therefore, in this embodiment, the control unit 70 determines the time-optimal trajectory for the slewing speed of the slewing body 12 and suppresses load swing at the target position. Furthermore, the trajectory referred to here includes not only the positional trajectory but also a temporal element, including the issue of where the suspended load LM passes at each time. In addition, the control unit 70 ensures that the suspended load LM reaches the target position as quickly as possible and suppresses continuous load swing of the suspended load LM after it reaches the target position as much as possible.

[0058] The target velocity calculation unit 702 of the control unit 70 calculates the turning angular velocity θ by the following calculation: ４ The transition of ' is determined. First, the dynamics model of crane 10 is derived according to Lagrange's equations of motion. At this time, the boom's luffing angular velocity θ ３ , the rotational angular velocity θ of the rotating body 12 ４ The speed l for raising (lowering) the rope is used as the control input. In Figure 2, if the coordinates of the suspended load LM are (x, y, z), then the kinetic energy T ｌ This can be expressed as shown in equations 1 and 2.

[0059] Furthermore, the potential energy U of the suspended load ｌ This is expressed by equation 3.

[0060] Then, the Lagrangian L, the Lagrangian with respect to the swing angle of the suspended load LM, is expressed as shown in Equation 4 below.

[0061] Furthermore, the dynamics (equations of motion) of the suspended load LM in the crane 10 can be expressed by the following equations 5 and 6.

[0062] <Verification Experiment> Here, the inventors of the present invention compared the simulation results with experimental results using a lab-scale (1 / 12th the size of the actual machine) slewing crane 10M in order to confirm the validity of the dynamics derived above. Figure 5 is a perspective view of the lab-scale experimental apparatus assuming the crane 10 according to this embodiment. Figure 6 is a block diagram of the same experimental apparatus.

[0063] The lab-scale 10M crane is powered by three AC motors M1, M2, and M3 (Figure 6), which enable the slewing of the slewing body, the luffing of the 16M boom, and the hoisting and lowering of the 50M main hoisting rope. The behavior of the 16M boom and the suspended load LM is measured by a known motion capture system. For each operation of slewing of the slewing body, luffing of the 16M boom, and hoisting (lowering) of the 50M main hoisting rope, a pre-created time history profile of speed and angular velocity is converted into a current value signal, which is a speed command signal, and transmitted to a DSP (Digital Signal Processing). From the DSP, the speed command signal is sent in real time to the servo controllers of each motor, and the device operates. Note that in Figure 6 and other references, boom luffing may be referred to as "Boom hoist," slewing of the slewing body as "Boom Rotation," and rope hoisting and lowering as "Rope hoist."

[0064] To first confirm the validity of the dynamics, the inventors compared simulation results with experimental results (measurements) of the swing at the target position (residual load swing) under two conditions: a simple, arbitrary single-motion trajectory based on a cycloid curve, and a compound motion trajectory in which the slewing body, the elevation of the 16M boom, and the hoisting of the 50M main hoisting rope are performed simultaneously.

[0065] The following are the specifications of the experimental apparatus and the conditions for confirming its validity. Boom length L: 2.0 (m) Distance between the base end of the boom (center of rotation) and the center of rotation of the slewing body (boom offset distance) a: -0.368 (m) Length of the main hoisting rope before the start of rotation l: 2.0 (m) Mass of the suspended load LM m: 1.0 (kg) Target rotation angle θ ４ｄ : 90 (degrees) Main winding rope winding distance l ｄ : -1.0 (m) Boom elevation angle θ before rotation begins ３ : Boom elevation angle θ during 60-degree rotation ３ｄ -15 (degrees)

[0066] On the other hand, as an example, the specifications of the actual crane 10 at the work site are shown below. Boom length L: 26 (m) Distance between the base end of the boom (center of rotation) and the center of rotation of the slewing body (boom offset distance) a: 1.1 (m) Boom elevation angle: 35.0 (degrees) Length of main hoisting rope l: 18.0 (m) Mass of suspended load LM m: 3.0 to 4.0 (T) Target slewing angle θ ４ｄ : 120 (degrees) Working radius: 16.0 (m)

[0067] Figure 7 shows another slewing speed profile for comparison with the slewing speed profile of the slewing body 12 according to this embodiment, and is an example of a profile used in the experiment (slewing speed (angular velocity) for single slewing motion). Figure 8 shows another slewing speed profile for comparison with the slewing speed profile of the upper body according to this embodiment, and is an example of a profile used in the experiment (slewing speed (angular velocity) for combined motion). In this case, the time for each section is t1 = t2 = t3 = 2.0 (sec). In addition to the slewing speed profile, Figure 8 also shows speed profiles related to the changes in boom elevation angle and rope length.

[0068] Figures 9A, 9B, 9C, and 9D are graphs showing the time evolution of the slewing angle (Figure 9A), slewing angular velocity (Figure 9B), slewing angular acceleration (Figure 9C), and suspended load swing angle (Figure 9D) in this verification experiment. Similarly, Figures 10A, 10B, 10C, and 10D are graphs showing the time evolution of the slewing angle (Figure 10A), slewing angular velocity (Figure 10B), slewing angular acceleration (Figure 10C), and suspended load swing (Figure 10D) in this verification experiment. Note that each figure in Figure 9 corresponds to the single slewing motion described above, and each figure in Figure 10 corresponds to the combined motion described above. In each figure, "sim" shows the simulation results, and "exp" shows the experimental results.

[0069] As shown in the graphs in Figure 9 and Figure 10, the simulation results and experimental results show good agreement for each characteristic of the swing of the suspended load LM that occurs in any trajectory, under both single and combined slewing conditions. Therefore, this verification result confirms the validity of the crane load swing dynamics model constructed as described above.

[0070] <Regarding the two-stage S-shaped trajectory> The inventors have provided a two-stage S-shaped trajectory in the acceleration zone and the deceleration zone, and the target rotation angle θ of the crane 10. ４ｄ To achieve this, we have discovered a control method that allows the turret to rotate in the shortest possible time and reach the target rotation angle, both in the case of a single rotation operation and in the case of a combined operation involving rotation, boom luffing, and main hoisting rope hoisting (lowering).

[0071] Figure 11 shows an example of a turning angular velocity trajectory, including a two-stage S-shaped trajectory in a single turning motion. Equation 7 represents the trajectory in Figure 11, and Equation 8 represents the maximum turning angular velocity. Note that the trajectory in Figure 11 is asymmetrical along the time axis, but the trajectory may also be symmetrical. Here, the total turning time T in Figure 8 can be divided into acceleration sections t1, t2, t3, constant speed section t4, and deceleration sections t5, t6, t7. Also, the maximum turning angular velocity is θ. ４ｍａｘ ', the speed ratio of the step section (constant speed section) to the maximum angular velocity in the angular velocity trajectory of the acceleration section and deceleration section is r１ ,r ２ As mentioned above, the target turning angle (the turning angle achieved at time T) is θ ４ｄ Let's assume that.

[0072] Figure 12 shows an example of the trajectory of the rotational angular velocity, including a two-stage S-shaped trajectory in a compound operation. Also, the boom luffing angular velocity θ in Figure 12. ３ Equation 9 shows the equation representing the orbit of ', along with the maximum elevation angular velocity θ. ３ｍａｘ Equation 10 shows the '. Also, Equation 11 shows the equation representing the trajectory of the hoisting (lowering) speed l' of the main hoisting rope 50 (suspension rope), and the maximum hoisting (lowering) speed l'. ｍａｘ The equation is shown in Equation 12. Note that the target elevation angle is θ. ３ｄ The target hoisting rope length is l ｄ Furthermore, t ｈ These are the times for each section shown in Figure 12. In the combined operation shown in Figure 12, the boom 16 is rotated in the upright direction during the slewing motion, and the main hoisting rope 50 is wound up.

[0073] In this embodiment, considering applicability to an actual crane 10, the constraints in the simulation include not only the time intervals of the two-stage S-shaped trajectory and the residual swing angle after the slewing stops, but also the maximum slewing angular velocity θ, which is a mechanical physical constraint of the crane 10. ４ ' and maximum rotational angular acceleration θ ４ Set the ''. The objective function is shown in Equation 13, and the constraints are shown in Equations 14 to 17. Note that the objective function and constraints are not limited to these.

[0074]

[0075] As mentioned above, the dynamics (equations of motion) of the suspended load LM in the crane are shown in equations 5 and 6, and the two-stage S-shaped trajectory is shown in equation 7. In addition, the trajectory of the elevation angular velocity of the boom 16 and the trajectory of the hoisting speed of the main hoisting rope 50 are shown in equations 9 to 12.

[0076] Equation 15 above shows the allowable swing angle of the suspended load LM. Equation 16 shows the slewing angular velocity θ on the machine. ４ The constraints of ' are shown, and equation 17 is given by the rotational angular acceleration θ on the machine. ４ The constraints are shown. These constraints depend on the structure of the drive system, including the hydraulic circuit of the crane 10, and therefore should be set in advance according to the crane (working machine) in question.

[0077] Furthermore, although the above embodiment describes a configuration in which a two-stage S-shaped trajectory is set in the acceleration and deceleration zones of the turning motion, the present invention is not limited thereto. As will be described in detail later, a three-stage S-shaped trajectory or more stages of S-shaped trajectory may be set.

[0078] <Second Embodiment> Next, a second embodiment of the present invention will be described. This embodiment differs from the first embodiment described above in that it focuses on reducing the load on the boom 16 during rotation. Points that are the same as in the first embodiment will be omitted from the explanation, or will be explained by referring to a part of the first embodiment.

[0079] In this embodiment, the target speed calculation unit 702 sets the speed for the rotation of the boom 16 such that the boom 16 rotates in the upright direction during the acceleration zone of the rotational angular velocity of the slewing body 12, and rotates in the lowering direction during the deceleration zone. The set speed is reflected in the command signal by the command signal generation unit 703 and input to the boom drive unit 72.

[0080] In this embodiment, the target speed calculation unit 702 sets the speed for raising and lowering the main winding rope 50 so that the suspended load LM is raised in the acceleration zone of the slewing angular velocity of the slewing body 12, and the suspended load LM is lowered in the deceleration zone. The set speed is reflected in the command signal by the command signal generation unit 703 and input to the winch drive unit 73.

[0081] In other words, in this embodiment, when the slewing motion of the slewing body 12 switches from the acceleration range to the deceleration range, the boom 16 rises to its highest position and then lowers back to its original elevation angle. Similarly, when the slewing motion of the slewing body 12 switches from the acceleration range to the deceleration range, the suspended load LM is positioned at its highest position and then lowers back to its original height.

[0082] With this configuration, it becomes possible to suppress the stress on the lower boom 16A of the boom 16 during the slewing motion, thereby extending the lifespan of the boom 16 and, consequently, the crane 10.

[0083] In addition, the luffing of the boom 16, the raising or lowering of the main hoisting rope 50, or one of these may be combined with the slewing motion.

[0084] <First Embodiment> Next, the effects of the two-stage S-shaped trajectory according to the first embodiment described above will be explained in detail using an embodiment. Note that the present invention is not limited to the following embodiments.

[0085] As an example, sequential quadratic programming is used for the optimization calculation to find solutions that satisfy the above equations. Here, the analysis conditions for single and combined rotational motions are shown as the following cases. (Single rotational motion) ・Case R1: Both rotational angular velocity and rotational angular acceleration are constrained, and the load rotates 90 degrees to the target rotational angle. ・Case R2: Both rotational angular velocity and rotational angular acceleration are constrained, and the load rotates 120 degrees to the target rotational angle. ・Case R3: Both rotational angular velocity and rotational angular acceleration are constrained, the load rotates 90 degrees to the target rotational angle, and the length of the main winding rope is half that of Case R1. ・Case R4: Both rotational angular velocity, rotational angular acceleration, and load swing angle are constrained, and the load rotates 90 degrees to the target rotational angle. (Combined motion) - Case C1: Both rotational angular velocity and rotational angular acceleration are constrained, the vehicle rotates 90 degrees to the target rotational angle, and rope hoisting occurs during rotation. - Case C2: Both rotational angular velocity and rotational angular acceleration are constrained, the vehicle rotates 90 degrees to the target rotational angle, and boom erection occurs during rotation. - Case C3: Both rotational angular velocity and rotational angular acceleration are constrained, the vehicle rotates 90 degrees to the target rotational angle, and rope hoisting and boom erection occur during rotation.

[0086] Table 1 shows the experimental conditions for each analysis and experimental apparatus.

[0087]

[0088] Furthermore, the constraints in the analysis are shown in Table 2.

[0089]

[0090] As shown in Tables 1 and 2, in this embodiment, the constraints for angular velocity, angular acceleration, residual load swing, and time in each acceleration / deceleration section are set to common values ​​for all conditions. However, in case R4, stricter constraints are considered, and additional constraints are added so that the load swing angle during operation is half of the maximum swing angles in the circumferential and radial directions that occur in case R1. Furthermore, in the combined operating conditions of cases C1, C2, and C3, the time t in the acceleration / deceleration section during rope hoisting (lowering) and boom luffing operations is set. ｈ Each of these is set to 2.0 seconds, and the constant speed section is varied so that the sum of the acceleration / deceleration sections and the time of these sections is equal to the total rotation time T. In addition, in case C3, conditions are set with different patterns for rope hoisting / lowering and boom luffing (C3-1 to C3-4).

[0091] <Simulation Results of Single Turning Motion> Figures 13 through 16 show the analysis results for cases R1, R2, R3, and R4. Figure 13A shows the turning angle (θ) in case R1. ４ Figure 13B is a graph showing the time course of the turning angular velocity (θ) in caseR1. ４ This is a graph showing the time course of '). Note that Figure 13B also shows the boom luffing angular velocity and rope hoisting speed, but these values ​​are not actively changed during a single rotation operation so they can be ignored. Figure 13C shows the rotation angular acceleration (θ) in case R1. ４ This is a graph showing the time course of ''). Figure 13D is a graph showing the time course of the suspended load swing in case R1. The technical significance of each graph is the same for Figures 14 to 16. The experimental results exp shown superimposed on each graph will be described later.

[0092] Furthermore, the upper section of Table 3 shows the time for each section of the turning trajectory, the total operating time, and the speed ratio r of the stepped portion of the two-stage S-shaped trajectory (the boundary between the first and second S-shapes) calculated under each condition of single-turn operation. １ ,r ２ This shows the speed ratio, which is the speed of the stepped section divided by the maximum speed. １ This corresponds to the acceleration range, r ２ This corresponds to the deceleration range.

[0093]

[0094] (Case R1) According to the results of case R1 shown in Figures 13A to 13D, the angular velocity trajectory generated by the optimization calculation (Figure 13B) shows a symmetrical shape around the halfway point of the operation time (central time). In the acceleration section t1 (see Figure 11) and the deceleration section t7, the angular acceleration reaches the limit value (Figure 13C), and in the constant speed section t4, the angular velocity also shows a speed close to the limit value (Figure 13B). The constant speed section t4 shows a value close to 0 (almost non-existent). At the point of maximum speed during the turn, centrifugal force causes the suspended load LM to swing radially, similar to the circumferential direction (Figure 13D). However, at the final target angle point, these two-dimensional load swings are sufficiently controlled.

[0095] (Case R2) As shown in Figures 14A to 14D, the results for case R2 show that, similar to case R1, the generated trajectory exhibits a symmetrical shape around the halfway point of the operating time (Figure 14B). In the acceleration sections t1 and t3 (Figure 11) and the deceleration sections t5 and t7, the angular acceleration reaches the limit (Figure 14C), and in the constant speed section t4, the angular velocity also reaches the limit (Figure 14B). The constant speed section t4 at maximum speed is longer than in case R1, and the radial swing is also large in this section (Figure 14D). However, the load swing in the two-dimensional direction is sufficiently controlled at the target angle point.

[0096] (Case R3) As shown in Figures 15A to 15D, the results for case R3 show that, similar to case R1, the generated trajectory is symmetrical around the halfway point of the operation time (Figure 15B). Similar to case R2, the angular acceleration reaches the limit in the acceleration sections t1 and t3 and the deceleration sections t5 and t7 (Figure 15C). On the other hand, the angular velocity does not reach the limit in the constant speed section t4, which shows the maximum speed (Figure 15B). Because the rope length is shorter than in case R1, the load swing during operation oscillates with a smaller period than in case R1 (Figure 15D). The load swing in the two-dimensional direction is controlled at the target angular point.

[0097] (Case R4) As shown in Figures 16A to 16D, the results for case R4 show that, similar to case R1, the generated trajectory is symmetrical around the halfway point of the operation time (Figure 16B). Similar to case R1, the angular acceleration reaches the limit value in the acceleration section t1 and the deceleration section t7 (Figure 16C). Although the operation time is increased by approximately 14% compared to case R1, the amount of load swing during the turning motion is kept within the constraints (Figure 16D). In addition, the maximum angular velocity in the constant speed section t4 is also smaller than in case R1 (Figure 16B). Furthermore, load swing is sufficiently controlled at the target angle point (Figure 16D).

[0098] <Simulation Results of Combined Motion> Similar to the previous figures, Figures 17 through 22 show the analysis results for cases C1, C2, and C3. In addition, the lower section of Table 3 shows the time intervals t1 to t7 for each section of the slewing trajectory, the total operating time T, and the speed ratios r1 and r2 of the stepped sections of the two-stage S-shaped trajectory, calculated for each condition of the combined motion. For case C3, the analysis results for conditions in which the rope hoisting, lowering, and boom luffing patterns were changed are shown as C3-1 (Figure 19), C3-2 (Figure 20), C3-3 (Figure 21), and C3-4 (Figure 22). The other conditions are shown in Tables 1 and 2.

[0099] (Case C1) As shown in Figures 17A to 17D, the results for case C1 show that the acceleration and deceleration sections of the rotation speed (angular velocity) differ in terms of the time of each section and the speed ratio of the steps (Figure 17B). In other words, unlike the conditions for the single rotation motion (cases R1, R2, R3, R4), it shows an asymmetrical trajectory centered around the halfway point of the motion time. Also, the time from the deceleration section t5 to t7 is shorter than the time from the acceleration section t1 to t3 (Figure 17B). In the acceleration section t1 and the deceleration section t7, the angular acceleration is approximately at the upper limit of the limit value. At the target angle point, the rope length is wound up to half of what it was at the start of the rotation, and the load swing in the two-dimensional direction is sufficiently damped (Figure 17D).

[0100] (Case C2) As shown in Figures 18A to 18D for case C2, the acceleration and deceleration sections of the slewing speed differ in terms of time and speed ratio of each section. Here again, unlike the conditions for a single slewing motion, an asymmetrical trajectory is observed, although the degree of asymmetry and the amount of change are smaller compared to case C1. Also, unlike the other conditions, the suspended load LM swings radially due to the effect of the boom's luffing motion immediately after the start of the slewing (Figure 18D). However, at the target angle point after the end of the motion, the boom luffing angle changes to the target angle, and the load swing in the two-dimensional direction is sufficiently controlled (Figure 18D).

[0101] (Case C3) As shown in Figures 19A to 22D, the results for cases C3-1, C3-2, C3-3, and C3-4 show that, similar to cases C1 and C2, the acceleration and deceleration sections differ in terms of the time of each section and the speed ratio of the steps, resulting in an asymmetrical trajectory. Furthermore, comparing Figures 19, 20, 21, and 22, it can be seen that the rotation speed trajectory obtained by the optimization calculation differs depending on the conditions as the boom luffing trajectory and rope hoisting (lowering) trajectory patterns change. However, under all conditions, it can be seen that the residual load swing in the two-dimensional direction after the end of the operation is sufficiently damped (Figures 19D, 20D, 21D, and 22D).

[0102] Furthermore, under conditions where the rope length change and boom luffing change are symmetrical (case C3-1 and case C3-4, case C3-2 and case C3-3), the angular velocity profile shows a symmetrical shape in the time axis direction, and the load swing characteristics similarly show symmetrical results.

[0103] As described above, in the single turning motion from case R1 to R4, the turning speed, including the two-stage S-shaped trajectory obtained by the optimization calculation, shows an approximately symmetrical profile with respect to the time at half the total operating time.

[0104] In particular, the circumferential swing of the suspended load LM shows approximately the same amplitude but opposite signs at the end of the rotational acceleration (end of t3) and the start of rotational deceleration (start of t5), indicating that the circumferential load swing velocity is approximately the same at these times. Similarly, the radial swing of the suspended load LM shows approximately the same amplitude at the end of the rotational acceleration (end of t3) and the start of rotational deceleration (start of t5), indicating that the radial load swing velocity is the same but in opposite directions.

[0105] Figures 23A and 23B show superimposed graphs of the rotation speed during rotation and the swing angle of the suspended load LM for case R1 and R4, respectively. It can be confirmed that the rotation control of the present invention, based on a two-stage S-shaped trajectory, is effective in addressing the vibration damping problem of residual load swing. Furthermore, it has been confirmed that the two-stage S-shaped trajectory according to the present invention can achieve rotational movement in the shortest possible time while changing the speed ratio of each acceleration / deceleration section and stage, even when pre-set constraints are imposed on angular velocity, angular acceleration, load swing angle, etc.

[0106] Furthermore, the trajectories of the slewing speed obtained in cases C1, C2, and C3 show asymmetrical trajectories, with the time of each section and the speed ratio of the sections differing from those in the case of a single slewing motion. This is thought to be because changes in rope length and luffing angle affect the swing period of the suspended load LM and the inertial and centrifugal forces generated during the motion. In conditions where the rope is raised (lowered), as in cases C1 and C3, the rope length changes over time, so the swing period also changes, and the time required for the acceleration or deceleration section tends to change accordingly. Also, in conditions where the boom is luffed, as in cases C2 and C3, the boom luffing motion greatly affects the radial inertial force of the suspended load, so a large radial swing occurs at an earlier stage compared to conditions where the boom luffing angle does not change. However, by using an optimal slewing speed trajectory that also takes into account the radial dynamics of the suspended load LM due to the luffing motion, the two-dimensional load swing can be suppressed. Furthermore, these results confirm the effectiveness of the present invention, as it is possible to dampen vibrations at a target point at high speed not only in single-motion slewing but also in complex motions including rope hoisting and boom luffing by using the crane dynamics model and optimization method constructed in this invention.

[0107] <Lab-Scale Experiment Results> Using the aforementioned 10M crane experimental setup (Figure 5), the effectiveness of the speed trajectories of each operation obtained by the optimization calculations described above in controlling load swing was confirmed. The experimental conditions were set in the same way as above in order to compare with the simulation results. For each condition, speed command signals based on the trajectories of the slewing angular velocity, rope hoisting speed, and boom luffing angular velocity, which were optimized in the simulation results, were input in real time from the DSP to each servo controller.

[0108] In the graphs from Figure 13 to Figure 22, the time evolution of the measured values ​​for slewing angle, slewing angular velocity, slewing angular acceleration, and load swing in the circumferential and radial directions is shown using exp data. As shown in each figure, the experimental results show that the input trajectories obtained by optimization calculations are roughly reproduced for the slewing angular velocity, rope hoisting speed, and boom luffing angular velocity. Furthermore, the characteristics of the load swing occurring two-dimensionally under all conditions roughly match the simulation results, and residual load swing is sufficiently suppressed at the target angle.

[0109] Furthermore, the slightly smaller load swing during the experiment compared to the simulation results is thought to be due to the influence of damping forces such as friction generated by the structure of the device. The slight differences in the degree and phase of residual load swing compared to the simulation are presumed to be due to the same reason. However, even in the experimental results of case C2, which showed a relatively large residual load swing, the load swing was only about 10 mm (circumferential direction) for a rope length of 1000 mm, which is sufficiently small, and it can be said that residual load swing was suppressed.

[0110] The experimental results described above confirmed that, even in actual machines, the two-stage S-shaped trajectory-based turning control is effective in suppressing residual load swing, even when constraints are placed on maximum angular velocity, angular acceleration, and load swing during turning. In this process, considering the mechanical and physical constraints of the work machine, such as maximum turning angular velocity and maximum turning angular acceleration, we were able to find a pattern trajectory that allows for operation in the shortest possible time for efficient work.

[0111] As described above, in the above embodiment (example), the target velocity calculation unit 702 calculates the target velocity (angular velocity θ) of the slewing body 12 based on the equation of motion of the suspended load LM based on dynamics. ４ The equation of motion is calculated using at least the length L of the boom 16, the length l of the main hoisting rope 50, and the elevation angle θ. ３ This includes equations for the rotational direction and the radial direction, respectively. Based on these equations and predetermined constraints set as needed, the target velocity calculation unit 702 calculates the radial swing angle θ at the target position. １ and the rotational direction deflection angle θ ２The target speed (angular velocity θ) of the slewing body 12 is determined such that the angle is smaller than a predetermined threshold angle, and the total slewing time T (time of arrival) of the suspended load LM to the target position is minimized, according to the elapsed time t of the slewing body 12 to reach the target position. ４ Set ').

[0112] In this process, the target speed calculation unit 702 sets a speed profile that includes a two-stage S-shaped trajectory in both the acceleration and deceleration regions. Such a two-stage S-shaped trajectory can have the following effects: - The first stage of acceleration can intentionally generate a slight load swing. - The second stage of acceleration can allow the crane to rotate while suppressing the load swing in accordance with the load swing. - A constant centrifugal force can be applied in the constant speed section, and the timing of vibration damping can be controlled. - The second stage of deceleration can reduce the centrifugal force and suppress radial load swing. - The first stage of deceleration can suppress the remaining tangential load swing. Through the effects of each of the above processes, the forces acting on the crane 10 (inertial force, centrifugal force, Coriolis force) can be controlled.

[0113] Furthermore, in the above embodiment, the target velocity calculation unit 702 calculates the swing angle θ of the suspended load LM in two directions at the target position based on the equation of motion of the suspended load LM. １ θ ２ The target speed of the slewing body 12 can be set so that the angle of the slewing is smaller than a predetermined threshold angle and the time it takes for the suspended load LM to reach its destination is minimized. This allows the suspended load LM to be moved in the shortest possible travel time while suppressing load swing at the target position.

[0114] Furthermore, in the above embodiment, the target speed (change in angular velocity) of the slewing body 12 can be optimized so as to minimize the arrival time of the suspended load LM. In this case, the conditions for optimizing this problem include constraints on the swing of the suspended load LM.

[0115] Furthermore, in this embodiment, the calculations performed by the target speed calculation unit 702 include the length of the main winding rope 50 (position of the main hook 57) and the elevation angle θ of the boom 16. ３Since the equation of motion for the suspended load LM, which includes the length L (slewing radius) of the boom 16, is used, the swing of the suspended load LM can be suppressed with high precision, and the suspended load LM can be moved to the target position in a short time.

[0116] <Second Embodiment> Next, the second embodiment described above will be explained in detail using an example. Note that the present invention is not limited to the following embodiment. In this embodiment, first, the dynamic stress characteristics that occur in the boom 16, which is the main structure of the crane 10, during the rotational operation of the crane 10 were confirmed by actual machine experimentation. Table 4 shows the basic specifications of the actual crane. Here, θ ４ｄ This indicates the target turning angle.

[0117]

[0118] In this experiment, a skilled operator controlled the crane 10 to perform high-speed slewing and load swing control. The dynamic characteristics of the crane 10's slewing angular velocity and slewing angle were measured by a rotary encoder attached to a slewing bearing (not shown) located between the slewing body 12 and the traveling body 14. The swing (angle and position) of the suspended load during the operation of the crane 10 was determined by analyzing the video from a load monitoring camera located at the tip of the boom 16. The target of stress measurement was the lower boom 16A of the boom 16, where high stress occurs. Strain gauges were attached to parts where no specific stress, such as stress concentration, occurred, and the dynamic stress during the operation of the crane 10 was measured. Figure 24 shows the positions of the strain gauges attached to the lower boom 16A. The upper part of Figure 24 is a front view of the lower boom 16A, and the lower part is a side view thereof. Figure 25 is a graph showing the time changes of the measured stress, load swing, and slewing angle.

[0119] As shown in Figure 25, the measurement results revealed that the stress generated in the lower boom 16A fluctuates in sync with the amount of tangential swing of the suspended load (Load-sway), and that the maximum stress occurs when the swing of the suspended load is at its maximum. This confirmed that the stress experienced by the lower boom 16A during the slewing motion is mainly caused by fluctuations in bending stress due to the swing of the suspended load.

[0120] In this embodiment, a FEM (Finite Element Method) simulation model was constructed to evaluate the effectiveness of vibration damping and stress reduction due to the trajectory of the suspended load, which will be described in detail later. Figures 26 and 27 show an overview of the dynamic simulation model in this embodiment. Figure 26 is a perspective view of the crane 10 model, and Figure 27 is a side view of the crane 10 model. In this simulation model, the boom 16 and the main hoisting rope 50 are modeled as elastic bodies, while the slewing body 12 and the mast 20 (or gantry) are modeled as rigid bodies. The model of the main hoisting rope 50 is divided into elements to represent its actual flexible deformation characteristics. The suspended load LM (Figure 2) is treated as a point mass, with mass assigned to the nodes at the ends of the rope elements. The luffing motion of the boom 16 and the up-and-down motion of the main hoisting rope 50 reproduce the mechanisms of sheaves and winches, just like in the actual machine.

[0121] In this simulation model, the boom 16, mast 20 (or gantry), boom guy lines 24, and various ropes are modeled as elastic bodies using beam elements, while the slewing body 12 and various sheaves are treated as rigid bodies. The boom 16 is represented by placing nodes at the intersections of each grid and connecting them with beam elements. The cross-sectional and material properties of the boom guy lines 24 and other elements are defined based on the specifications of the actual machine. Rope elements are discretized in detail to represent the flexibility of the rope, and appropriate physical properties such as bending, torsion, and axial elongation are assigned depending on the type of rope. The lower end of the boom 16 is connected to the slewing body 12 with a pin, allowing for luffing. The slewing motion of the slewing body 12 is achieved by applying angular velocity to nodes on the slewing axis constrained to the slewing body 12. The luffing and hoisting motions are modeled by simulating the winding motion of the rope, and the length of the rope is adjusted accordingly. Each sheave is discretized using solid elements, defining contact conditions between the rope and the sheave, and replicating the actual motion of the rope as it moves through the sheave. Furthermore, translational constraints are imposed between the tip node of the boom luffing rope 38 and the end node of the boom guyline 24. The load is modeled as a point mass, with the mass assigned to the node at the end of the rope element.

[0122] To verify the validity of the dynamic simulation model, the slewing angular velocity trajectory in a portion of the reciprocating operation section of the crane 10, obtained from actual machine experiments, was used as input, and the tangential load swing and the stress generated in the lower boom 16A were analyzed. Figure 28 is a graph showing the time evolution of the slewing angular velocity trajectory and slewing angle under the operation of a skilled operator. Figure 29 is a graph showing the time evolution of the measured stress and the swing of the suspended load, corresponding to Figure 28. Figure 30 is a graph showing parts of Figures 28 and 29 superimposed.

[0123] Referring to Figures 28 to 30, it was confirmed that the load swing and stress fluctuations obtained in the simulation above showed similar trends to those observed in the actual machine experiment. In particular, the stress on the lower boom 16A fluctuated according to the load swing behavior and was consistent with the trends observed in the actual machine experiment. From these results, the validity of the constructed dynamic simulation model was confirmed.

[0124] Next, the influence of the axial motion of the crane 10 (slewing, raising and lowering of the boom 16, and rope hoisting), as well as the oscillations of radial and tangential loads, on the stress generated in the lower boom 16A was analyzed using FEM. Figure 31 is a graph showing a typical input trajectory, representing the time evolution of acceleration and velocity during slewing. 'a' is acceleration and 'v' is velocity. Table 5 summarizes the analysis conditions and input parameters.

[0125]

[0126] In cases 1 to 3 of Table 5, the slewing, boom luffing, and rope hoisting operations are performed individually based on the trajectory shown in Figure 31. The acceleration and deceleration phases are defined using the maximum acceleration value determined according to the mechanical performance of the crane 10. As an example, the durations t1, t2, and t3 (Figure 31) of each operation are set to 3 seconds. In cases 4 and 5, the crane 10 remains stationary, and an initial input of sway is applied to the suspended load LM in the radial and slewing (tangential) directions, respectively. Figure 32 is a perspective view showing the stress evaluation point SEP of the lower boom 16A in the FEM simulation. This point is reproduced using a beam element model of the cross-section of the lower boom 16A.

[0127] Figure 33 is a graph showing the simulation results for each operating condition shown in Table 5, illustrating the time evolution of the generated stress. The vertical axis of the graph represents the normalized stress, shown as a ratio to the maximum stress value observed in Case 1, which showed the highest stress among all conditions. Initial static stress generated by a pre-set load is offset to ensure a fair comparison, and only stress fluctuations resulting from dynamic motion are considered. As a result, it was found that large stress fluctuations occur under conditions involving horizontal motion, particularly slewing (Case 1) and tangential load oscillation (Case 5). In contrast, the other cases showed minimal fluctuations. In both Case 1 and Case 5, the stress response exhibited vibrational behavior, and the vibration of the boom 16 and the load coincided, as confirmed by FEM analysis. These results indicate that the structure of the crane 10 affects the stress response of the lower boom 16A and the oscillation of the load during horizontal motion (slewing). The boom 16 is connected to the slewing body 12 by a pin, allowing for luffing motion and making it less susceptible to the effects of moment generation in the luffing direction. In contrast, horizontal motion generates structural moments, approximating the behavior of a fixed-end cantilever, i.e., a structure (beam) with one end fixed and the other free. Therefore, the influence of horizontal motion on structural stress is more significant. Based on these results, this embodiment focuses on horizontal mechanical characteristics such as boom rotation (slewing) and tangential load oscillation, and provides a suspended load trajectory aimed at reducing structural stress.

[0128] From the results above, it is necessary to suppress the tangential swing of the suspended load in order to reduce the amount of damage to the crane 10 (machine). In this embodiment, an optimal trajectory for suppressing the tangential swing of the suspended load is proposed. This trajectory includes the two-stage S-shaped trajectory described in the first embodiment above, and further includes a three-stage S-shaped trajectory with additional S-shaped trajectories in the acceleration and deceleration stages. Furthermore, in order to efficiently transport the crane 10, an STT trajectory (Straight Transfer Transformation, STT) which adds the luffing motion of the boom 16 to the slewing motion was added, and the effect of these trajectories on the tangential swing of the suspended load was confirmed.

[0129] The STT trajectory described above simultaneously controls the slewing motion of the crane and the luffing motion of the boom, moving the projected trajectory of the boom tip and the suspended load linearly in a plan view, i.e., on the XY plane. This method cancels out the effects of centrifugal force that normally occurs during slewing, enabling efficient transport of the suspended load LM over the shortest distance and suppression of load swing. In terms of control, it has fewer state variables compared to conventional models, reducing the computation time required for optimal control calculations and improving the practicality of the control. Furthermore, because it can take into account changes in rope length, it enables transport while maintaining a constant height of the suspended load and flexible control according to on-site requirements. The implementation of the STT track involves the following: "Minimum Control Time of Load in Linear Conveying Method by Simultaneous Operation of Luffing, Slewing, and Hoisting of a Rotary Crane, Ying SHEN, Kazuhiko TERASHIMA, Ken'ichi YANO, Kensuke Suzuki, Transactions of the Society of Instrument and Control Engineers, Vol. 3, No. 10, 70 / 79 (2004)", and "Optimal Control of Rotary Crane Using the Straight Transfer Transformation Method to Eliminate Residual Vibration, Ying SHEN, Kazuhiko TERASHIMA and Ken'ichi YANO, Transactions of the Society of Instrument and Control Engineers, Vol. 39, No. 9." See 817 / 826 (2003), "Modeling and optimal control of a rotary crane using the straight transfer transformation method, Kazuhiko Terashima, Ying Shena, Ken'ichi Yano, Control Engineering Practice 15 (2007) 1179–1192."

[0130] Here, to represent the trajectory under each condition, a three-stage S-shaped trajectory is used as a reference, and constraints are set on the parameters of time and each stage of the S-shaped trajectory. Figure 34 is a diagram showing the three-stage S-shaped trajectory and is a graph showing the change in turning angular velocity. Equation 18 below is the equation for the three-stage S-shaped trajectory in Figure 34, and equation 19 is the equation for the maximum turning angular velocity. The notation of the signs in Figure 34 is the same as in Figure 11.

[0131]

[0132]

[0133] Furthermore, equations 20 and 21 show the rotation angle θ in STT. ３ＳＴＴ This is the formula for calculating the boom elevation angle corresponding to [the specified value]. Note that in equation 20, x ０ , y ０ This indicates the tip position of the boom 16 at the start of the rotational movement, x ｄ , y ｄ This indicates the tip position of the boom 16 at the end of its rotational movement. Both represent x and y coordinates in a plan view (see Figure 42).

[0134] Table 6 shows the constraints for each trajectory. Here, optimization calculations are performed according to the purpose. Specifically, the parameters in Table 6 are applied to Figure 34 for each of the following: a two-stage S-shaped trajectory, a three-stage S-shaped trajectory, STT, and the trajectory when operated by a skilled person (skilled operator trajectory). Note that, as shown in Table 6, in this example only STT includes the luffing motion of the boom 16.

[0135]

[0136] Table 7 also shows the optimization objective functions corresponding to the conditions in Table 6.

[0137]

[0138] Here, T represents the operating time, and θ2amp represents the maximum tangential amplitude of the suspended load. For the objective function, the two-stage S-shaped trajectory and the skilled operator trajectory evaluate minimizing time T, while the three-stage S-shaped trajectory and STT evaluate minimizing the maximum tangential load swing, i.e., the maximum amplitude θ2amp. The maximum amplitude of the suspended load and the operating time are compared using the results of the two-stage S-shaped trajectory as a baseline. The objective function and constraints in this optimization calculation are shown in Equations 22 to 28.

[0139] First, the objective function is given by equation 22 or equation 23.

[0140] The constraints are expressed as the equations of motion for the crane in equations 5 and 6 above.

[0141] Furthermore, the time divisions and stage ratios of the three-stage S-shaped trajectory shown in Equation 7 can be expressed by the following Equation 24.

[0142] Furthermore, the allowable value for the amount of residual load swing at the target position is set by Equation 25. In Equation 25, the period Tp is defined by Equation 26. Also, in Equation 25, the maximum residual load swing in the radial direction is θ. １ｒｍａｘ θ is the maximum residual load swing in the tangential direction. ２ｒｍａｘ Let's assume that.

[0143] Furthermore, the permissible values ​​for angular velocity and angular acceleration are set by equations 27 and 28.

[0144] Table 8 shows the calculation and operating conditions, Table 9 shows the upper and lower limit constraints, and Table 10 shows the constraints for each inequality. In this calculation, the parameters and constraints for crane 10 were determined based on a lab-scale slewing crane (Figure 5) with a rope length ratio of approximately 1 / 9th that of the actual crane shown in Table 4. Furthermore, constraints are given so that residual load swing at the target point is sufficiently suppressed.

[0145]

[0146]

[0147]

[0148] Figure 35 shows a block diagram for generating the optimal trajectory. In this embodiment, in step S01, initial conditions for optimization are set. In step S02, the specifications of the optimization problem are set. At this time, the constraints include the aforementioned crane dynamics, speed, acceleration, time segment and stage ratio, and allowable load swing angle. Furthermore, in step S03, a trajectory is generated based on equation 18, and in step S04, the behavior of the suspended load is calculated based on equations 5 and 6. Then, in step S05, the objective function and constraints are evaluated based on equations 22 to 28. The optimization from steps S03 to S05 is repeated to determine the optimal trajectory.

[0149] Figure 36A is a graph showing the time evolution of the rotation angle, boom elevation angle, and rope length of a two-stage S-shaped trajectory, representing the optimization results in an embodiment of the present invention. Figure 36B is a graph showing the time evolution of the rotation angular velocity, boom angular velocity, and rope length velocity. Figure 36C is a graph showing the time evolution of the rotation angular acceleration, boom angular acceleration, and rope length acceleration. Figure 36D is a graph showing the time evolution of the suspended load swing angle.

[0150] Figure 37A is a graph showing the time evolution of the rotation angle, boom elevation angle, and rope length of a three-stage S-shaped trajectory, representing the optimization results in an embodiment of the present invention. Figure 37B is a graph showing the time evolution of the rotation angular velocity, boom angular velocity, and rope length velocity. Figure 37C is a graph showing the time evolution of the rotation angular acceleration, boom angular acceleration, and rope length acceleration. Figure 37D is a graph showing the time evolution of the suspended load swing angle.

[0151] Figure 38A is a graph showing the time course of the rotation angle, boom elevation angle, and rope length of the STT track, representing the optimization results in an embodiment of the present invention. Figure 38B is a graph showing the time course of the rotation angular velocity, boom angular velocity, and rope length velocity. Figure 38C is a graph showing the time course of the rotation angular acceleration, boom angular acceleration, and rope length acceleration. Figure 38D is a graph showing the time course of the suspended load swing angle.

[0152] Figure 39A is a graph showing the time course of the rotation angle, boom luffing angle, and rope length of the skilled operator's trajectory, which is the optimization result in an embodiment of the present invention. Figure 39B is a graph showing the time course of the rotation angular velocity, boom angular velocity, and rope length velocity. Figure 39C is a graph showing the time course of the rotation angular acceleration, boom angular acceleration, and rope length acceleration. Figure 39D is a graph showing the time course of the suspended load swing angle.

[0153] Furthermore, as mentioned above, Table 11 and Figure 40 show the operating time and load swing amount (angle) under other conditions, with the results for the two-stage S-shaped trajectory as the baseline.

[0154]

[0155] Referring to Figures 36D and 37D, it can be seen that the maximum amplitude is suppressed in the three-stage S-shaped trajectory compared to the two-stage S-shaped trajectory. Furthermore, as shown in Figure 38D, the STT trajectory significantly reduces the load swing of the suspended load, resulting in highly effective results. However, achieving the STT trajectory requires rapid boom luffing to maintain the straight trajectory of the suspended load. In boom-luffing type slewing cranes, the luffing speed is considerably smaller than the slewing speed. For this reason, achieving the STT trajectory can be difficult in some cases. Nevertheless, by appropriately combining luffing and slewing movements, it has been confirmed that load swing in both the tangential and radial directions can be effectively reduced, as shown in Figure 38D.

[0156] On the other hand, as shown in Figure 39C, the operating track used by a skilled operator exhibited characteristic acceleration and deceleration movements in the deceleration section, and an improvement in operating speed was expected compared to the two-stage S-shaped track. However, this speed improvement was limited to 0.5%, and no significant difference was observed. Meanwhile, the maximum amplitude in the tangential direction of the suspended load increased by 8.4%, which may increase the load on the machine. From this perspective, the two-stage S-shaped track, the three-stage S-shaped track, and the STT track can be considered relatively more effective tracks.

[0157] As explained above, it was confirmed that combining rotational and luffing movements, such as in a three-stage S-shaped trajectory or an STT trajectory, is more effective in reducing tangential load swing than a two-stage S-shaped trajectory. Therefore, in this embodiment, a combined trajectory (boom luffing angular velocity trajectory) that takes into account the maximum operating speed of the luffing movement in addition to the rotational movement is proposed. Furthermore, a trajectory (rope vertical velocity trajectory) that simultaneously performs the vertical movement of the main hoisting rope 50, which affects the vibration period of the suspended load LM, in addition to the luffing movement was also investigated.

[0158] Figure 41 is a graph showing the boom luffing angular velocity trajectory and rope vertical velocity trajectory, which are proposed in conjunction with the three-stage S-shaped trajectory of the rotational motion. The equations representing these trajectories are shown in Equations 29 and 30.

[0159] Note that the time for each section of the boom elevation angular velocity track is t ｌ The time for each section of the rope vertical velocity track is t ｈ This is shown. The boom luffing angular velocity trajectory performs an raising operation in the first half of the rotation region relative to the target point, and a lowering operation in the second half of the rotation region. Figure 42 is a plan view showing the boom tip trajectory of the proposed trajectory that combines rotation and luffing operations. Figure 42 also shows a simple rotation trajectory and the aforementioned STT trajectory. Furthermore, the boom luffing angular velocity trajectory performs a hoisting operation in the first half of the rotation region relative to the target point, and a lowering operation in the second half of the rotation region. In addition, a cycloid curve is adopted as an S-shaped trajectory in the boom luffing angular velocity trajectory and in the acceleration and deceleration regions of the boom luffing angular velocity trajectory, similar to rotation. The S-shaped trajectory is not limited to this.

[0160] Here, the trajectory patterns compared in this embodiment are shown below. caseS1: Compound trajectory (slewing + boom luffing) including a three-stage S-shaped trajectory caseS2: Compound trajectory (slewing + rope up / down) including a three-stage S-shaped trajectory caseS3: Compound trajectory (slewing + boom luffing + rope up / down) including a three-stage S-shaped trajectory caseS4: Compound trajectory (slewing + boom luffing + rope up / down) including a two-stage S-shaped trajectory

[0161] Incidentally, the objective function is defined by Equation 22 based on minimizing the maximum amplitude of the suspended load in order to reduce the damage amount of the crane 10. Also, the operation time T is set in the same manner as the result of the aforementioned two-stage S-shaped trajectory. Furthermore, the effect of reducing the maximum amplitude of the suspended load is also confirmed for the two-stage S-shaped trajectory when considering the combined operation. In addition, the additional constraint conditions for the constraint conditions of Equations 24 to 28 are shown in Equations 31 to 34. At this time, the total boom hoisting / lowering time is T ｌ , and the total rope up / down time is T ｈ and is defined as such.

[0162] Equations 31 and 32 are the constraint conditions in the time intervals of the previous Equations 29 and 30. Equation 33 indicates the speed limit values of the boom hoisting / lowering angular velocity and the rope up / down speed. Equation 34 indicates the acceleration limit values of the boom hoisting / lowering angular acceleration and the rope up / down acceleration.

[0163] Examples of the limit values included in the above equations are shown in Tables 12 and 13. At this time, the constraint conditions regarding the boom hoisting / lowering speed and the rope up / down speed are set referring to the performance of the actual crane.

[0164]

[0165]

[0166] Also, the constraint conditions for each operation condition are shown in Table 14.

[0167]

[0168] Regarding each proposed trajectory described above, an optimization calculation regarding minimizing the maximum load swing amplitude considering the constraint conditions and an experiment on a laboratory-scale slewing crane based on the result were carried out, and the effectiveness regarding reducing the maximum load swing of the suspended load of the proposed trajectory was confirmed. For the optimization calculation, a known sequential quadratic programming (SQP) method was used. Incidentally, the crane 10 of the laboratory scale used is the same as that in the aforementioned FIGS. 5 and 6 and the description thereof.

[0169] As mentioned above, the behavior of the boom 16 and the suspended load LM is measured by a known motion capture system. In this embodiment as well, the time history profiles of the rotation of the slewing body 12, the luffing of the boom 16, and the rope up and down speed of the main hoisting rope 50, which were created in advance, are converted into speed command signals and transmitted to the DSP (Digital Signal Processing). Subsequently, the speed command signals are transmitted in real time from the DSP to each servo controller, thereby controlling the operation of the lab-scale slewing crane.

[0170] Figures 43A to 46D show the results of optimization calculations and lab-scale experiments for each of the proposed trajectories described above. Figure 43A is a graph showing the time evolution of the slewing angle, boom angle, and rope length in this embodiment. Figure 43B is a graph showing the time evolution of the slewing angular velocity, boom angular velocity, and rope length velocity in this embodiment. Figure 43C is a graph showing the time evolution of the slewing angular acceleration, boom angular acceleration, and rope length acceleration in this embodiment. Figure 43D is a graph showing the time evolution of the suspended load swing angle in this embodiment. The graphs in groups 44, 45, and 46 are similar. Group 43 corresponds to Case S1, group 44 to Case S2, group 45 to Case S3, and group 46 to Case S4.

[0171] Furthermore, Table 15 shows the maximum radial and tangential load swing angles and total operating time for a simple two-stage S-shaped trajectory (without boom luffing or rope raising / lowering) and for each proposed trajectory Case S1, S2, S3, and S4.

[0172]

[0173] As shown in Table 15, it was confirmed that combining the slewing motion with the luffing motion of the boom or the up-and-down motion of the rope reduces the maximum amplitude in the tangential direction of the suspended load. In particular, in case S3, where the slewing motion, boom luffing motion, and up-and-down motion of the rope are performed simultaneously, the amplitude is reduced most effectively. In this case, an effect of reducing the amplitude by more than 30% was obtained compared to a simple two-stage S-shaped trajectory.

[0174] From the above, the following effects were confirmed. <Effects of Boom Luffing Operation> By adding boom luffing operation during rotation, it is possible to reduce the working radius of the crane 10. As a result, the centrifugal force and inertial force acting on the suspended load LM are reduced, and it is thought that the amplitude of the suspended load LM can be suppressed. In addition, boom luffing operation has the function of directly controlling the radial vibration of the suspended load LM. By performing boom luffing operation in conjunction with the rotational acceleration and deceleration operation of the crane 10, it is possible to directly control the radial vibration of the suspended load. As a result, it is thought that the overall operation time can be shortened. This result indicates that the overall efficiency of crane operations can be improved.

[0175] <Effects of Rope Up / Down Movement> It was found that the up / down movement of the rope is a factor that directly affects the vibration period of the suspended load LM. It was shown that by winding the rope during the rotational movement and shortening the rope length relative to the initial rope length, it is possible to effectively reduce the inertial force acting on the suspended load LM and suppress the maximum swing amplitude of the suspended load LM. From this, it was confirmed that dynamic control of the rope length is effective in suppressing vibration of the suspended load LM.

[0176] <Simulation and FEM Analysis Results> From the above results, it was confirmed that the trajectory that combines the three axes of rotation, luffing, and rope movement (three-axis combined motion trajectory) is the most efficient motion trajectory that enables transport in a short time while suppressing load swing. Next, the stress generated in the lower boom 16A was compared by FEM simulation for the motion trajectory of a skilled operator and the three-axis combined motion trajectory. First, in order to define the rotational angular velocity trajectory, an optimization calculation was performed under the conditions of the actual crane, similar to a lab-scale rotational crane. Table 16 shows the basic specifications of the actual crane, Table 17 shows the details of the upper and lower limit constraints in the simulation, and Table 18 shows the inequality constraints.

[0177]

[0178]

[0179]

[0180] For the maximum speed and maximum acceleration of slewing, boom luffing, and rope raising / lowering movements, constraints were set based on the specifications of the actual machine. Furthermore, for the combined motion trajectory, time constraints were set to ensure that the motion time was the same as that of a skilled operator, and optimization was performed to minimize the maximum load swing amplitude.

[0181] Figures 47A to 49D show the simulation results for each condition. Figure 47A is a graph showing the time changes of the slewing angle, boom angle, and rope length in the skilled operator's trajectory in this embodiment. Figure 47B is a graph showing the time changes of the slewing angular velocity, boom angular velocity, and rope length velocity in the same trajectory. Figure 47C is a graph showing the time changes of the slewing angular acceleration, boom angular acceleration, and rope length acceleration in the same trajectory. Figure 47D is a graph showing the time changes of the suspended load swing angle in the same trajectory.

[0182] Figure 48A is a graph showing the time evolution of the slewing angle, boom angle, and rope length in a compound operating trajectory including a three-stage S-shaped trajectory in this embodiment. Figure 48B is a graph showing the time evolution of the slewing angular velocity, boom angular velocity, and rope length velocity. Figure 48C is a graph showing the time evolution of the slewing angular acceleration, boom angular acceleration, and rope length acceleration. Figure 48D is a graph showing the time evolution of the suspended load swing angle.

[0183] Figure 49A is a graph showing the time changes of the slewing angle, boom angle, and rope length in a compound operating trajectory including a two-stage S-shaped trajectory in this embodiment. Figure 49B is a graph showing the time changes of the slewing angular velocity, boom angular velocity, and rope length velocity. Figure 49C is a graph showing the time changes of the slewing angular acceleration, boom angular acceleration, and rope length acceleration. Figure 49D is a graph showing the time changes of the suspended load swing angle.

[0184] As a result of the simulation, the maximum load swing amplitude was reduced by 24.3% in the case of a composite motion trajectory including a two-stage S-shaped trajectory and 28.8% in the case of a composite motion trajectory including a three-stage S-shaped trajectory with respect to the trajectory of a skilled operator. From this result, it was confirmed that the proposed trajectory is effective in the actual crane specifications as well as in the laboratory-scale crane. Next, FEM simulations were performed based on the velocity trajectories of FIGS. 47B, 48B, and 49B obtained by optimization, and the stress amplitude generated in the lower boom 16A was evaluated. FIGS. 50A, 50B, and 50C show the results of load swing and stress amplitude in each of the trajectories of a skilled operator, a composite motion trajectory including a three-stage S-shaped trajectory, and a composite motion trajectory including a two-stage S-shaped trajectory. FIG. 51 is a graph comparing the respective results. As a result of the FEM simulation, the stress amplitude generated in the lower boom 16A was reduced by 17.1% in the case of a composite motion trajectory including a two-stage S-shaped trajectory and 17.7% in the case of a composite motion trajectory including a three-stage S-shaped trajectory compared to the trajectory of the skilled operator model. From this result, the effectiveness of reducing the damage amount to the working machine of the proposed trajectory could be clarified.

[0185] Next, regarding the influence of the difference in the amplitude of the generated stress obtained above on the life of the crane 10, it was calculated based on a simple fatigue evaluation method of ISO 4301-1, which is an international standard for cranes. Equation 35 is an equation for calculating the stress spectrum coefficient Kp in the fatigue evaluation method.

[0186]

[0187] The design life is determined based on the coefficient Kp of Equation 35. Here, P ｉ is the magnitude of the load of the suspended load LM during the use of the crane 10, P ｍａｘ is the maximum load of the suspended load LM expected to be handled by the crane 10, C ｉ is the average value of the number of load cycles at each load level, C Ｔ is the total of the individual load cycles at all load levels, m ｓ indicates the slope constant. The slope coefficient m ｓ is determined by the joining method of the evaluation target. When the crane 10 has a lattice structure, since the lattice type joining is applied, m ｓ = 5 is applied. Also, Pｉ / P ｍａｘ This shows the ratio of the stress amplitude under evaluation to the maximum stress amplitude. Here, based on the previous FEM simulation results, in the case of a skilled operator's trajectory, P ｉ / P ｍａｘ = 1.0, in the case of the trajectory proposed in this embodiment (three-stage S-shaped trajectory), P ｉ / P ｍａｘ Let's assume it equals 0.823. C ｉ / C Ｔ This represents the frequency of occurrence of the stress amplitude being evaluated.

[0188] Figures 52A and 52B show the load profiles for the work assumed in the fatigue evaluation described above. Figure 52A represents the skilled operator's trajectory, and Figure 52B corresponds to the trajectory proposed in this embodiment (three-stage S-shaped trajectory). In this assumed work, work with load (load rate: 100%) and work without load (load rate: 55%) are performed at 50% frequency each. Furthermore, based on the FEM analysis results mentioned earlier, the proposed trajectory assumes a 17.7% reduction in load compared to the skilled operator's trajectory.

[0189] Based on the above assumptions, the stress spectral coefficient Kp was calculated to be 0.527 for the skilled operator track and 0.208 for the proposed track. Furthermore, when the stress history grade was set to S0 and the ratio of the maximum number of operating cycles was calculated, the result showed that the proposed track had approximately 2.7 times the maximum number of cycles (design life) compared to the skilled operator track. From the above evaluation results, it was confirmed that the proposed method contributes significantly to improving the design life of the crane 10 compared to conventional operation.

[0190] As described above, in this embodiment, based on the analysis results of skilled operator operation on a real crane 10, it was confirmed that the tangential load swing of the boom 16 affects the stress generated in the lower boom 16A. Furthermore, the effectiveness of the proposed trajectory, which consists of a compound trajectory combining slewing, boom luffing, and rope up / down movements, was verified through optimization analysis and experiments on a lab-scale crane. As a result, it was confirmed that the trajectory of a so-called three-axis compound motion, which simultaneously performs slewing, boom luffing, and rope up / down movements, is the most effective trajectory for suppressing the maximum load swing amplitude of the suspended load in the same operating time as that of a skilled operator or a two-stage S-shaped trajectory. The effectiveness of this proposed trajectory was also reproduced in FEM simulations on a real crane and was consistent with the lab-scale verification results. In addition, it was confirmed that the maximum stress amplitude of the lower boom 16A generated in the proposed trajectory was reduced by up to 17.7% compared to the skilled operator trajectory. This stress reduction effect significantly suppresses the stress generated in the boom 16 compared to the conventional skilled operator track. Life calculations based on standards for fatigue evaluation of the crane 10 revealed that it is possible to achieve a life extension of approximately 2.7 times compared to the skilled operator track. These results confirm that the proposed track not only enables efficient operation but also significantly reduces the amount of damage to the crane 10, demonstrating its high practicality.

[0191] The crane 10 and its embodiments according to each embodiment of the present invention have been described above. With this configuration, it is possible to efficiently move the suspended load LM to the target position while suppressing the swing of the suspended load LM at the target position. However, the present invention is not limited to these forms. The present invention can take the following modified embodiments, for example.

[0192] (1) The structure of the crane 10 is not limited to that shown in Figure 1, and may be a crane with other structures. The crane 10 may have a jib connected to the tip of the boom 16, and the crane 10 may be a tower crane or the like. Also, the crane 10 may have a gantry instead of a mast 20.

[0193] (2) The equations of motion of the suspended load LM used in the calculations performed by the target velocity calculation unit 702 are not limited to those used in the previous embodiment. Other equations of motion of the suspended load LM for the slewing direction and radial direction, respectively, including the length of the boom 16, the length of the main hoisting rope 50, and the elevation angle of the boom 16, may be used. In this case, the complete dynamics model based on the known Newton's equations of motion or Lagrange's equations of motion, or equations of motion obtained by eliminating any small terms from the complete dynamics model, may be used.

[0194] (3) In the above embodiment, the radial swing angle θ is at both the target position and during rotational movement. １ , rotational direction swing angle θ ２ Although the conditions relating to each of these have been described in terms of how they are set, the present invention is not limited thereto. The swing angle condition may be set only for the target position, or only during rotational movement. Furthermore, some of the constraint conditions described above may be applied.

[0195] (4) The slewing angular velocity profile may not be input to the slewing drive unit 71, but may be displayed on the display unit 87 so that the operator can operate according to the profile.

[0196] (5) In the second embodiment and the second embodiment described above, the luffing of the boom 16 and the raising and lowering of the main hoisting rope 50 were mainly combined in relation to the slewing motion, but it is also possible to combine only one of these. Furthermore, when the luffing of the boom 16 is combined, the aforementioned STT track may be adopted.

[0197] (6) The S-shaped trajectory in the above embodiment constitutes the curved trajectory of the present invention. In a turning operation, the speed trajectory includes an acceleration zone from zero to maximum speed and a deceleration zone from maximum speed to zero again. Each of the acceleration zone and the deceleration zone is composed of multiple stages of curved trajectory. In the case of a two-stage S-shaped trajectory, one intermediate speed is provided between the start of the turn and the maximum speed, or between the maximum speed and the stop of the turn. In the case of a three-stage S-shaped trajectory, two intermediate speeds are provided between the start of the turn and the maximum speed, or between the maximum speed and the stop of the turn.

[0198] The speed trajectory from the start of a turn to the intermediate speed is composed of a single S-shaped trajectory. In this case, the S-shaped trajectory rises as a curve with the time axis (X-axis) as its tangent, and while having a downward-convex curved shape, it reaches an inflection point at half the intermediate speed. From this inflection point, it rises with a tangent parallel to the speed axis (Y-axis), and while having an upward-convex curved shape, it eventually reaches the intermediate speed. At this point, the tangent of the S-shaped trajectory becomes parallel to the time axis. The same applies to the S-shaped trajectory between the intermediate speed and the maximum speed. Note that the intermediate speed region does not necessarily require a predetermined time; the next S-shaped trajectory may start immediately after the first S-shaped trajectory reaches the intermediate speed (the intermediate speed time is effectively zero). In this case, the intermediate speed constitutes the inflection point between two consecutive S-shaped trajectories.

[0199] On the other hand, the speed trajectory from the maximum speed to the intermediate speed in the deceleration zone is composed of a single S-shaped trajectory. In this case, the S-shaped trajectory descends in a curve with the time axis as its tangent, and while having an upwardly convex curved shape, it reaches an inflection point at a speed midway between the maximum speed and the intermediate speed. From this inflection point, it descends with a tangent parallel to the speed axis, and while having an downwardly convex curved shape, it eventually reaches the intermediate speed. At this point, the tangent of the S-shaped trajectory becomes parallel to the time axis. The same applies to the S-shaped trajectory between the intermediate speed and zero speed (turning stop). In this case as well, the intermediate speed zone does not necessarily require a predetermined time, and the next S-shaped trajectory may start immediately at the intermediate speed.

[0200] The same applies to tracks with three, four or more stages. In this case, the number of intermediate speeds increases, and S-shaped tracks (curved tracks) are provided between them.

[0201] In the above explanation, an S-shaped trajectory was used as an example of a curved trajectory, but it is not necessarily limited to this. Furthermore, the S-shaped trajectory is not limited to one composed of a cycloid curve, but may be composed of other curves. The cycloid curve mentioned above is an example of a trigonometric function curve in this invention. A cycloid curve is expressed as a combination of trigonometric functions. The S-shaped trajectory (curved trajectory) is not limited to these curves, but may consist of other curves such as a cycloid curve or an Nth-degree polynomial.

[0202] The first aspect of the present invention provides a work machine. The work machine comprises a lower body, an upper body, a luffing body, a load rope, a slewing drive unit, a luffing body length information acquisition unit, a slewing angle detection unit, a rope length information acquisition unit, a movement information receiving unit, a speed setting unit, and a command signal generation unit. The upper body is supported on the lower body so as to be rotatable around a slewing center axis extending in the vertical direction. The luffing body includes a base end of the luffing body and a tip end of the luffing body opposite to the base end, both supported on the upper body so as to be rotatable in the luffing direction around a horizontal rotation center axis. The load rope hangs down from the tip end of the luffing body and is connected to a load. The slewing drive unit receives a predetermined angular velocity command signal and can rotate the upper body around the slewing center axis at a speed corresponding to the angular velocity command signal. The luffing body length information acquisition unit acquires luffing body length information, which is information corresponding to the length of the luffing body in the longitudinal direction of the luffing body, which is the direction connecting the base end and the tip end of the luffing body. The rotation angle detection unit detects the rotation angle of the upper body around the rotation center axis. The luffing angle detection unit detects the luffing body's luffing angle around the rotation center axis. The rope length information acquisition unit acquires rope length information, which is information corresponding to the length of the load rope between the tip end of the luffing body and the suspended load. The movement information receiving unit receives movement information, including a target rotation angle, to move the suspended load to a predetermined target position around the rotation center axis by the rotational movement of the upper body, starting from the initial state in which the suspended load is lifted by the load rope.If the angle of the suspension rope with respect to the vertical direction when the raised body is viewed along the rotational direction of the upper body is defined as the radial swing angle, and the angle of the suspension rope with respect to the vertical direction when the raised body is viewed along the radial direction of the rotational movement of the upper body is defined as the rotational swing angle, then the speed setting unit sets the angular velocity of the upper body to reach the target position to include multiple curved trajectories in each of the acceleration and deceleration regions, based on the equations of motion of the suspension load for each of the rotational and radial directions, which include at least the length of the raised body, the length of the suspension rope, and the raised angle, such that the radial swing angle and the rotational swing angle at the target position are smaller than a predetermined threshold angle and the time it takes for the suspension load to reach the target position is minimized. The command signal generation unit generates and outputs the angular velocity command signal corresponding to the angular velocity set by the speed setting unit.

[0203] According to this configuration, the speed setting unit can set the angular velocity of the upper body based on the equation of motion of the suspended load, such that the swing angle of the suspended load at the target position is smaller than the threshold angle and the time it takes for the suspended load to reach the target position is minimized. In particular, since the trajectory of the slewing angular velocity is set to include multiple curved trajectories in both the acceleration and deceleration zones, the suspended load can be moved with the minimum possible travel time while suppressing the swing at the target position.

[0204] In the working machine according to the second aspect of the present invention, the curved trajectory may be composed of a trigonometric function curve in the first aspect.

[0205] With this configuration, the forces acting on the suspended load (inertial force, centrifugal force, and Coriolis force) can be stably controlled by each process on the trigonometric function curve.

[0206] In the third aspect of the present invention, the work machine may, in the first or second aspect, have the command signal generation unit input the generated angular velocity command signal to the slewing drive unit.

[0207] According to this configuration, the upper body can be automatically rotated based on the angular velocity command signal generated by the command signal generation unit, so as to move the suspended load to the target position while suppressing load swing at the target position.

[0208] In the fourth aspect of the present invention, the speed setting unit may further set the rotational angular velocity of the upper body such that, during the rotational operation, the rotational angular velocity of the upper body becomes smaller than a preset maximum rotational angular velocity.

[0209] In the fifth aspect of the present invention, the speed setting unit may further set the angular velocity of the upper body such that, during the rotational operation, the rotational angular acceleration of the upper body becomes smaller than a preset maximum rotational angular acceleration.

[0210] In the sixth aspect of the present invention, the work machine may, in the first to fifth aspects, have the speed setting unit set the angular velocity based on the following equations I and II as the equations of motion for the suspended load. ２ (1 + θ) １ ２ )θ １ ''+ml ２ θ １ θ ２ θ ２ '' + mlL(cosθ) ３ -θ １ sinθ ３ )θ ３ -ml ２ θ ２ θ ４ ''+ml ２ θ １ (θ １ ' ２ +θ ２ ' ２ ) - mLl(sinθ ３ +θ １ cosθ ３ )θ ３ ' ２ -ml(lθ) １ +Lsinθ ３ )θ ４ ' ２ -2 ml ２ θ２ ’θ ４ ’ + mglθ １ + 2mlθ １ ’l’(1 + θ １ ２ ) - mθ １ l’ ２ - mLθ １ θ ３ ’l’sinθ ３ + 2mlθ １ θ ２ θ ２ ’l’ = 0 ··· (Equation I) ml ２ θ １ θ ２ θ １ ’’ + ml ２ (1 + θ ２ ２ )θ ２ ’’ + mlLθ ２ sinθ ３ θ ３ ’’ + ml(Lsinθ ３ + lθ １ )θ ４ ’’ + ml ２ θ ２ (θ １ ’ ２ + θ ２ ’ ２ ) - mLlθ ２ cosθ ３ θ ３ ’ ２ - ml ２ θ ２ θ ４ ’ ２ + 2mLlθ ３ ’θ ４ ’cosθ ３ + 2ml ２ θ １ ’θ ４ ’ + mglθ ２ + 2mlθ １ θ ４ ’l’ - mLθ ２ θ ３ ’l’sinθ ３ + 2mlθ ２ ’l’(1 + θ ２ ２ ) - mθ ２ l’ ２ + 2mlθ １ θ ２ θ１ 'l' = 0 ... (Equation II) (where θ １ : Radial swing angle of the suspended load, θ ２ : Swing angle of the suspended load, θ １ ': Radial angular velocity of the suspended load, θ ２ ': Angular velocity of the swing direction of the suspended load, θ １ '': Radial angular acceleration of the suspended load, θ ２ '': Angular acceleration of the swing direction of the suspended load, θ ３ : The elevation angle of the relief body with respect to the vertical direction, θ ３ ': The rate of change of the elevation angle, θ ３ '': Acceleration of change in the aforementioned elevation angle, θ ４ : The rotation angle of the upper body, θ ４ ': The rotational angular velocity of the upper body, θ ４ '': rotational angular acceleration of the upper body, g: gravitational acceleration, L: length of the undulating body, l: length of the suspension rope from the tip of the undulating body to the suspended load, l': rate of change of the length of the suspension rope, m: mass of the suspended load)

[0211] In the seventh aspect of the present invention, the work machine may, in the first to sixth aspects, have the speed setting unit set the angular velocity of the upper body up to the target position to include a two-stage curved trajectory in both the acceleration and deceleration regions.

[0212] Furthermore, in the eighth aspect of the present invention, the work machine may, in the first to sixth aspects, have the speed setting unit set the angular velocity of the upper body up to the target position to include three stages of curved trajectories in both the acceleration and deceleration regions.

[0213] In the ninth aspect of the present invention, the work machine may, in the first to eighth aspects, further set the speed setting unit to rotate the luffing body in the upright direction in the acceleration region of the angular velocity of the upper body, and rotate the luffing body in the downward direction in the deceleration region.

[0214] In the tenth aspect of the present invention, the work machine may, in the first to eighth aspects, further set the speed setting unit to raise the suspended load in the acceleration region of the angular velocity of the upper body and lower the suspended load in the deceleration region, thereby setting the speed of the winding up and winding down of the suspension rope.

[0215] In the eleventh aspect of the present invention, the work machine may, in the first to eighth aspects, have a speed setting unit that sets the speed for the rotation of the luffing body such that in the acceleration region of the angular velocity of the upper body, the luffing body rotates in the upright direction, and in the deceleration region, the luffing body rotates in the downward direction, and sets the speed for the hoisting and lowering of the load rope such that in the acceleration region of the angular velocity of the upper body, the load is raised, and in the deceleration region, the load is lowered.

[0216] According to the present invention, a work machine is provided that can efficiently move a suspended load to a target position and suppress load swing at the target position.

Claims

1. A lower body; an upper body supported on the lower body so as to be rotatable around a pivot axis extending vertically; a luffing body including a base end and a tip end opposite to the base end, supported on the upper body so as to be rotatable in the luffing direction around a horizontal rotation axis; a load rope hanging down from the tip end of the luffing body and connected to a load; a pivot drive unit that receives a predetermined angular velocity command signal and can pivot the upper body around the pivot axis at an angular velocity corresponding to the angular velocity command signal; a luffing body length information acquisition unit that acquires luffing body length information, which is information corresponding to the length of the luffing body in the longitudinal direction of the luffing body, which is the direction connecting the base end and the tip end of the luffing body; a pivot angle detection unit that detects the pivot angle of the upper body around the pivot axis; and a luffing angle detection unit that detects the luffing angle of the luffing body around the rotation axis. A rope length information acquisition unit acquires rope length information which is information corresponding to the length of the load rope between the tip of the luffing body and the load; and a movement information receiving unit receives movement information including a target rotation angle for moving the load to a predetermined target position around the rotation center axis by the rotational movement of the upper body, starting from an initial state in which the load is lifted by the load rope. A work machine comprising: a speed setting unit that sets the angular velocity of the upper body to the target position to include multiple curved trajectories in each of the acceleration and deceleration zones, such that the radial swing angle and the rotational swing angle at the target position are smaller than a predetermined threshold angle and the time it takes for the suspended load to reach the target position is minimized, based on equations of motion for the suspended load in each of the rotational and radial directions, which include at least the length of the luffing body, the length of the suspended load rope, and the luffing angle, so that the radial swing angle and the rotational swing angle at the target position are smaller than a predetermined threshold angle and the time it takes for the suspended load to reach the target position is minimized; and a command signal generation unit that generates and outputs an angular velocity command signal corresponding to the angular velocity set by the speed setting unit.

2. The work machine according to claim 1, wherein the curved track is composed of trigonometric function curves.

3. The work machine according to claim 1 or 2, wherein the command signal generation unit inputs the generated angular velocity command signal to the slewing drive unit.

4. The work machine according to claim 1 or 2, wherein the speed setting unit further sets the rotational angular velocity of the upper body such that the rotational angular velocity of the upper body is less than a preset maximum rotational angular velocity during the rotational operation.

5. The work machine according to claim 1 or 2, wherein the speed setting unit further sets the angular velocity of the upper body such that the rotational angular acceleration of the upper body is less than a preset maximum rotational angular acceleration during the rotational operation.

6. The speed setting unit sets the angular velocity based on the following equations (I) and (II) as the motion equations of the suspended load, for the working machine according to claim 1 or 2. ml ２ (1+θ １ ２ )θ １ ’’+ml ２ θ １ θ ２ θ ２ ’’+mlL(cosθ ３ -θ １ sinθ ３ )θ ３ ’’-ml ２ θ ２ θ ４ ’’+ml ２ θ １ (θ １ ’ ２ +θ ２ ’ ２ )-mLl(sinθ ３ +θ １ cosθ ３ )θ ３ ’ ２ -ml(lθ １ +Lsinθ ３ )θ ４ ’ ２ -2ml ２ θ ２ ’θ ４ ’+mglθ １ +2mlθ １ ’l’(1+θ １ ２ )-mθ １ l’ ２ -mLθ １ θ ３ ’l’sinθ ３ +2mlθ １ θ ２ θ ２ ’l’=0 ・・・(Equation I) ml ２ θ １ θ ２ θ １ ’’+ml ２ (1+θ ２ ２ )θ ２ ’’+mlLθ ２ sinθ ３ θ ３ ’’+ml(Lsinθ ３ +lθ １ )θ ４ ’’ + ml ２ θ ２ (θ １ ’ ２ +θ ２ ’ ２ ) - mLlθ ２ cosθ ３ θ ３ ’ ２ - ml ２ θ ２ θ ４ ’ ２ +2mLlθ ３ ’θ ４ ’cosθ ３ +2ml ２ θ １ ’θ ４ ’ + mglθ ２ +2mlθ １ θ ４ ’l’ - mLθ ２ θ ３ ’l’sinθ ３ +2mlθ ２ ’l’(1 + θ ２ ２ ) - mθ ２ l’ ２ +2mlθ １ θ ２ θ １ ’l’ = 0 ··· (Equation II) (where θ １ : Radial deflection angle of the suspended load, θ ２ : Swinging deflection angle of the suspended load, θ １ ’: Radial deflection angular velocity of the suspended load, θ ２ ’: Swinging deflection angular velocity of the suspended load, θ １ ’’: Radial deflection angular acceleration of the suspended load, θ ２ ’’: Swinging deflection angular acceleration of the suspended load, θ ３ : Heaving angle of the heaving body with respect to the vertical direction, θ ３ ’: Change speed of the heaving angle, θ ３ ’’: Change acceleration of the heaving angle, θ<0000​​​​'': rotational angular acceleration of the upper body, g: gravitational acceleration, L: length of the undulating body, l: length of the suspension rope from the tip of the undulating body to the suspended load, l': rate of change of the length of the suspension rope, m: mass of the suspended load) 7. The work machine according to claim 1 or 2, wherein the speed setting unit sets the angular velocity of the upper body up to the target position to include a two-stage curved trajectory in each of the acceleration and deceleration regions.

8. The work machine according to claim 1 or 2, wherein the speed setting unit sets the angular velocity of the upper body up to the target position to include three stages of curved trajectories in both the acceleration and deceleration zones.

9. The work machine according to claim 1 or 2, wherein the speed setting unit sets the speed of rotation of the luffing body such that in the acceleration region of the angular velocity of the upper body, the luffing body rotates in the upright direction, and in the deceleration region, the luffing body rotates in the downward direction.

10. The work machine according to claim 1 or 2, wherein the speed setting unit sets the speed for raising and lowering the load rope such that the load is raised in the acceleration region of the angular velocity of the upper body and the load is lowered in the deceleration region.

11. The work machine according to claim 1 or 2, wherein the speed setting unit sets the speed for the rotation of the luffing body such that in the acceleration region of the angular velocity of the upper body the luffing body rotates in the upright direction and in the deceleration region the luffing body rotates in the down direction, and sets the speed for the hoisting and lowering of the load rope such that in the acceleration region of the angular velocity of the upper body the suspended load is raised and in the deceleration region the suspended load is lowered.

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