Swing control device for work machine and work machine equipped with same

Abstract

To provide a swing control device for a working machine capable of accurately swinging an upper swinging body at a target swinging speed, and a working machine equipped with the same.SOLUTION: A swing control device 100 is used for a crane 10 having an upper swing body 12, a lower travel body 14, a swing drive unit 101, and an attachment 10S. The swing control device 100 has a controller 110. The controller 110 operates the swing drive unit 101 based on feed-forward control so that the upper swing body 12 swings at a target swing speed. The controller 110 generates a correction command signal by correcting a reference command signal set in advance corresponding to a predetermined target swing speed based on information on fluctuation factors that cause the swing speed to vary, and inputs the correction command signal to the swing drive unit 101.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a swing control device for a work machine and a work machine equipped with the same. [Background technology]

[0002] Conventionally, a mobile crane has been known that includes a lower traveling body, an upper rotating body, and an attachment such as a boom or a jib (Patent Document 1). The attachment is attached to the front of the upper rotating body so that it can be raised and lowered. When a load is connected to a hoisting rope hanging from the tip of the attachment, the load can be lifted. In addition, with such a crane, the upper rotating body may be rotated while the load is lifted. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2008-143635 Summary of the Invention [Problem to be solved by the invention]

[0004] In the above-described crane, even if an attempt is made to rotate the upper rotating body by inputting a command signal corresponding to a desired target rotation speed into the drive unit, there are cases in which a load is placed on the upper rotating body due to the influence of wind or the like, and the actual rotation speed does not reach the target rotation speed.

[0005] The present invention has been made in consideration of the above problems, and its object is to provide a swing control device for a work machine that can rotate an upper swing body at a target swing speed with high precision, and a work machine equipped with the same. [Means for solving the problem]

[0006] A swing control device for a work machine according to one aspect of the present invention is used for a work machine having a lower body, an upper swing body swingably supported on the lower body, a swing drive unit that swings the upper swing body with a drive force corresponding to the magnitude of an input command signal, and an attachment supported on the upper swing body so as to be swingable in a hoisting direction. The swing control device includes a controller that operates the swing drive unit based on feedforward control so that the upper swing body swings at a predetermined target swing speed, corrects a reference command signal that is preset corresponding to the target swing speed based on information related to fluctuation factors that cause the swing speed to fluctuate, to generate a corrected command signal, and inputs the corrected command signal to the swing drive unit.

[0007] According to this configuration, the controller corrects the reference command signal taking into account the fluctuation factors, so that the upper rotating body can be rotated at the target rotation speed with high precision while suppressing variations due to the fluctuation factors.

[0008] In the above configuration, the fluctuation factors may include external fluctuation factors related to a work site of the work machine.

[0009] According to this configuration, even if external factors that cause fluctuations in the rotation speed at the work site change, the upper rotating body can be rotated at the target rotation speed with high precision.

[0010] The above configuration may further comprise a wind information acquisition unit capable of acquiring wind information including at least one of wind volume and wind direction at the work site, and the external fluctuation factor may include the wind information.

[0011] According to this configuration, even if wind information changes at the work site, the upper rotating body can be rotated at the target rotation speed with high precision.

[0012] In the above configuration, the system may further include a rotation angle detection unit capable of detecting the rotation angle of the upper rotating body relative to the lower main body, the wind information including the wind direction, and the controller may correct the reference command signal based on at least the wind direction and the rotation angle.

[0013] With this configuration, the upper rotating body can be rotated accurately at a target rotation speed while taking into account the load that the attachment receives from the wind, depending on whether the attachment supported on the upper rotating body is heading from upwind to downwind or from downwind to upwind.

[0014] The above configuration may further include a working radius acquisition unit capable of acquiring information relating to the working radius of the attachment, and the controller may correct the reference command signal based on at least the wind information and the working radius.

[0015] According to this configuration, the controller can take into account the working radius of the attachment and the lateral moment (lateral to the upper rotating body) that the attachment receives from the wind, thereby enabling the upper rotating body to rotate accurately at the target rotation speed.

[0016] In the above configuration, the work site may further include an inclination detection unit capable of detecting an angle of inclination of the upper rotating body relative to a horizontal plane, and the external fluctuation factor may include the angle of inclination.

[0017] According to this configuration, the upper rotating body can be rotated with high precision at a target rotation speed while taking into account the effect of gravity on the attachment supported on the upper rotating body depending on the slope of the work site.

[0018] In the above configuration, the system may further include a rotation angle detection unit capable of detecting the rotation angle of the upper rotating body relative to the lower main body, and the controller may correct the reference command signal based on at least the tilt angle and the rotation angle.

[0019] With this configuration, the upper rotating body can be rotated accurately at a target rotation speed while taking into account the effect of gravity on the attachment supported on the upper rotating body, depending on whether the attachment is heading up the slope or down the slope.

[0020] The above configuration may further include a working radius acquisition unit capable of acquiring information relating to the working radius of the attachment, and the controller may correct the reference command signal based on at least the tilt angle and the working radius.

[0021] With this configuration, the upper rotating body can be rotated accurately at the target rotation speed while taking into account the effect of gravity on the attachment depending on the slope of the work site and the lateral moment that the attachment actually receives depending on the working radius.

[0022] The above configuration may further comprise a load detection unit capable of detecting the load of a load suspended from the tip of the attachment, and the controller may correct the reference command signal based on at least the load.

[0023] According to this configuration, the load that the lifting load imparts to the attachment and the rotational motion of the upper rotating body is taken into consideration, and the upper rotating body can be rotated at a target rotation speed with high precision.

[0024] In the above configuration, the fluctuation factors may include internal fluctuation factors related to the work machine.

[0025] According to this configuration, even if the internal fluctuation factors that cause fluctuations in the rotation speed at the work site change, the upper rotating body can be rotated at the target rotation speed with high precision.

[0026] In the above configuration, the internal fluctuation factors may include factors that change the rotation speed of the upper rotating body in a disconnected state, and the disconnected state may be a state in which the attachment is detached from the upper rotating body.

[0027] According to this configuration, by taking into account the variable factors that occur when the upper rotating body, which does not include an attachment, rotates relative to the lower running body, the upper rotating body can be rotated accurately at the target rotation speed when the attachment is attached to the upper rotating body.

[0028] In the above configuration, the slewing drive unit may include a slewing motor that rotates to rotate the upper slewing body by receiving hydraulic oil, and a valve mechanism that opens and closes to change the flow rate of hydraulic oil supplied to the slewing motor in accordance with the input command signal.

[0029] According to this configuration, the rotation speed of the upper rotating body can be stably set to the target rotation speed by optimizing the command signal input by the controller to the valve mechanism.

[0030] In the above configuration, the controller may receive information relating to the fluctuation factors and correct the reference command signal using a neural network.

[0031] According to this configuration, even under conditions requiring advanced calculations in which multiple parameters change, it is possible to obtain an optimal corrected command signal taking into account the influence of each parameter.

[0032] A work machine according to another aspect of the present invention comprises a lower body, an upper rotating body rotatably supported on the lower body, a rotation drive unit that rotates the upper rotating body with a driving force corresponding to the magnitude of an input command signal, an attachment supported on the upper rotating body rotatably in a raising and lowering direction, and the rotation control device for a work machine described above.

[0033] According to this configuration, the upper rotating body can rotate at a target rotation speed with high precision while suppressing variations due to variable factors. [Effects of the Invention]

[0034] According to the present invention, it is possible to provide a swing control device for a work machine that is capable of swinging an upper swing body at a target swing speed with high accuracy, and a work machine equipped with the same. [Brief explanation of the drawings]

[0035] [Figure 1] 1 is a side view of a work machine equipped with a swing control device according to an embodiment of the present invention. [Figure 2] 1 is a block diagram and a hydraulic circuit diagram of a work machine according to an embodiment of the present invention. [Figure 3] 10 is a graph showing the relationship between a target swing speed and a proportional valve command current value. [Figure 4] 10 is a graph showing changes over time in a target turning speed and an actual turning speed. [Figure 5] 4 is a flowchart showing correction control of internal fluctuation factors executed by a turning control device according to one embodiment of the present invention. [Figure 6] 10 is a graph showing the relationship between a target swing speed and a proportional valve command current value. [Figure 7] 10 is a graph showing a time transition of a proportional valve command current value. [Figure 8] 4 is a flowchart showing correction control of external fluctuation factors executed by a turning control device according to one embodiment of the present invention. [Figure 9] 10 is a flowchart showing correction control of external fluctuation factors executed by a turning control device according to a modified embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0036] Hereinafter, each embodiment of the present invention will be described with reference to the drawings. Fig. 1 is a side view of a crane 10 according to a first embodiment of the present invention. Note that, although directions such as "up," "down," "front," and "rear" are shown in each drawing hereinafter, these directions are shown for the sake of convenience in explaining the structure and assembly method of the crane 10 according to each embodiment, and do not limit the direction of movement or the manner of use of the crane according to the present invention.

[0037] The crane 10 includes an upper rotating body 12 corresponding to the crane body, a lower running body 14 (lower body) that rotatably supports the upper rotating body 12, an attachment 10S (also called a hoisting body) including a boom 16 and a jib 18, and a mast 20 that is a boom hoisting member. The upper rotating body 12 is supported by the lower running body 14 so as to be rotatable about a rotation center axis CL that extends in the vertical direction relative to the lower running body 14. A slewing bearing 12S (FIG. 1) is disposed between the upper rotating body 12 and the lower running body 14, and the upper rotating body 12 rotates due to the sliding (rotation) of the slewing bearing 12S. A counterweight 13 for adjusting the balance of the crane 10 is mounted on the rear of the upper rotating body 12. A cab 15 is provided at the front end of the upper rotating body 12. The cab 15 corresponds to the driver's seat of the crane 10.

[0038] The attachment 10S includes a base end portion supported on the upper rotating body 12 so as to be rotatable in the direction of elevation and a tip end portion opposite the base end portion, and is detachable from the upper rotating body 12.

[0039] 1 is a so-called lattice type boom, and is composed of a lower boom 16A, one or more (three in the illustrated example) intermediate booms 16B, 16C, and 16D, and an upper boom 16E. A jib 18, a rear strut 21 for rotating the jib 18, and a front strut 22 are rotatably connected to the tip of the upper boom 16E. The boom 16 is rotatably supported on the upper rotating body 12 around a rotation axis extending in the left-right direction with a boom foot pin 16S provided at the lower end as a fulcrum.

[0040] However, the present invention is not limited to a specific boom structure. For example, the boom may have no intermediate members, or may have a different number of intermediate members than those described above. Furthermore, the boom may be constructed of a single member.

[0041] The specific structure of the jib 18 is also not limited. The base end of the jib 18 is rotatably connected (pivoted) to the tip end of the upper boom 16E of the boom 16, and the rotation axis of the jib 18 is a horizontal axis parallel to the rotation axis (boom foot pin 16S) of the boom 16 relative to the upper rotating body 12.

[0042] The mast 20 has a base end and a pivoting end, and the base end is pivotally connected to the upper rotating body 12. The pivoting axis of the mast 20 is parallel to the pivoting axis of the boom 16 and is located immediately rearward of the pivoting axis of the boom 16. In other words, the mast 20 is pivotable in the same direction as the boom 16 is raised and lowered. Meanwhile, the pivoting end of the mast 20 is connected to the tip of the boom 16 via a pair of boom guy lines 24 on the left and right. This connection coordinates the rotation of the mast 20 and the rotation of the boom 16.

[0043] Furthermore, the crane 10 includes a pair of left and right backstops 23, a pair of left and right strut backstops 25 and guy lines 26, and a pair of left and right jib guy lines 28. The pair of left and right backstops 23 prevent the boom 16 from being blown backward by strong winds or the like.

[0044] The rear strut 21 is pivotally supported at the tip of the boom 16. The rear strut 21 is held in a position in which it projects from the tip of the upper boom 16E toward the boom erection side (left side in FIG. 1). A pair of left and right strut backstops 25 and a pair of left and right guy lines 26 are provided as means for holding this position.

[0045] The front strut 22 is disposed behind the jib 18 and is rotatably supported on the tip of the boom 16 (upper boom 16E) so as to rotate in conjunction with the jib 18. More specifically, a pair of left and right jib guy lines 28 are tensioned to connect the tip of the front strut 22 with the tip of the jib 18. Therefore, when the front strut 22 is rotated, the jib 18 is also rotated integrally with the front strut 22.

[0046] The crane 10 further includes various winches. Specifically, the crane 10 includes a boom hoist winch 30 for raising and lowering the boom 16, a jib hoist winch 32 for rotating the jib 18 in the hoisting direction, and a main hoist winch 34 and an auxiliary hoist winch 36 for hoisting and lowering a load. The crane 10 also includes a boom hoist rope 38, a jib hoist rope 44, a main hoist rope 50, and an auxiliary hoist rope 60. The positions of the winches 30, 32, 34, and 36 are not limited to those shown in FIG. 1.

[0047] The boom hoist winch 30 changes the distance between the two sheave blocks 40, 42 by winding in and letting out the boom hoist rope 38. This causes the mast 20 and, in turn, the boom 16, which is linked to the mast 20, to rotate in the hoisting direction.

[0048] The jib hoist winch 32 winds in and out the jib hoist rope 44 that is wound between the rear strut 21 and the front strut 22, thereby changing the distance between the two sheave blocks 47, 48 and rotating the front strut 22 relative to the rear strut 21. As a result, the jib hoist winch 32 raises and lowers the jib 18, which is linked to the front strut 22.

[0049] The main hoisting winch 34 changes the distance between the two sheaves 56, 58 by hoisting and lowering the load using the main hoisting rope 50. As a result, the main hook 57 connected to the main hoisting rope 50 hanging down from the tip of the jib 18 is hoisted up and down. In this manner, in this embodiment, the main hoisting rope 50 (hanging load rope) hangs down from the tip of the attachment 10S and is connected to the load via the main hook 57.

[0050] Similarly, when the auxiliary winch 36 winds up and lowers the load using the auxiliary hoisting rope 60, the auxiliary hook for the load (not shown) connected to the end of the auxiliary hoisting rope 60 is wound up or lowered.

[0051] 2 is a block diagram and a hydraulic circuit diagram of the crane 10 according to this embodiment. The crane 10 further includes a swing drive unit 101 and a swing control device 100.

[0052] The swing drive unit 101 swings the upper swing body 12 with a driving force according to the magnitude of an input command signal. The swing drive unit 101 has an engine 102, an ECU 103, a hydraulic pump 104, a swing motor 105, a control valve 106, and a proportional valve 107.

[0053] The engine 102 has a rotating output shaft, and receives a supply of fuel to rotate the output shaft. The driving force generated by the engine 102 rotates the hydraulic pump 104. The ECU 103 adjusts the amount of fuel supplied to the engine 102 in response to a rotation speed switching signal received from the controller 110, thereby adjusting the rotation speed of the engine 102.

[0054] The hydraulic pump 104 discharges hydraulic oil to be supplied to the swing motor 105. The swing motor 105 receives hydraulic oil from the hydraulic pump 104 and generates a driving force to rotate the upper swing body 12. The swing motor 105 has two ports, and receives hydraulic oil into one of the two ports and discharges hydraulic oil from the other port. Depending on the destination of the hydraulic oil, the swing motor 105 rotates to rotate the upper swing body 12 in one swing direction (right swing direction) or the opposite other swing direction (left swing direction).

[0055] The control valve 106 is disposed between the hydraulic pump 104 and the swing motor 105, and changes the flow rate and flow path of the hydraulic oil supplied from the hydraulic pump 104 to the swing motor 105. Specifically, when the swing motor 105 performs a right-hand swing operation or a left-hand swing operation, the control valve 106 operates to supply hydraulic oil from the hydraulic pump 104 to the swing motor 105 and to discharge the hydraulic oil discharged from the swing motor 105 to a tank. The control valve 106 is a pilot-operated three-position directional control valve having a pair of pilot ports.

[0056] When no pilot pressure is input to either of the pair of pilot ports, the control valve 106 is kept in a neutral position, and isolates the hydraulic pump 104 from the swing motor 105 .

[0057] When pilot pressure is input to the first pilot port, the control valve 106 is switched from the neutral position to the right swing position with a stroke corresponding to the magnitude of the pilot pressure. As a result, hydraulic oil is supplied from the hydraulic pump 104 to one oil chamber of the swing motor 105 at a flow rate corresponding to the stroke, and hydraulic oil is discharged from the other oil chamber of the swing motor 105. As a result, the swing motor 105 swings the upper swing body 12 in the right swing direction at a speed corresponding to the pilot pressure. The same applies when the upper swing body 12 swings in the left swing direction.

[0058] The proportional valve 107 receives a command signal input from the controller 110 and opens to input a pilot pressure corresponding to the command signal to the pilot port of the control valve 106. The proportional valve 107 is arranged between a pilot pump (not shown) and the control valve 106. Although one proportional valve 107 is shown in FIG. 2, two proportional valves 107 are provided corresponding to the pair of pilot ports. The two proportional valves 107 and the control valve 106 constitute a valve mechanism of the present invention. The valve mechanism opens to change the flow rate of hydraulic oil supplied to the swing motor 105 according to the input command signal.

[0059] The rotation control device 100 rotates the upper rotating body 12 by inputting a command signal to the rotation drive unit 101. The rotation control device 100 has a controller 110, a communication device 111, a server 112, a rotation speed meter 121, a rotation angle meter 122, an anemometer 123, an angle meter 124, a main body inclinometer 125, and a load meter 126 (load detection unit).

[0060] The controller 110 controls all operations of the crane 10, including the rotation of the upper rotating body 12. In particular, the controller 110 operates the rotation drive unit 101 based on feedforward control so that the upper rotating body 12 rotates at a target rotation speed. The functions of the controller 110 will be described in detail below.

[0061] The communication device 111 transmits various pieces of information input from the controller 110 to the server 112 , and also receives various pieces of information from the server 112 and inputs them to the controller 110 .

[0062] The server 112 is located in a remote location different from the work site of the crane 10. The server 112 functions as a management device that controls a plurality of cranes 10. In this embodiment, the server 112 has an advanced arithmetic processing function based on a neural network. Note that the functions of the server 112 may also be provided in the controller 110.

[0063] The rotation speed meter 121 detects the rotation speed of the upper rotating body 12 and inputs a signal corresponding to the detected speed to the controller 110.

[0064] The turning angle meter 122 detects the turning angle of the upper turning body 12 relative to the lower running body 14, and inputs a signal corresponding to the detected angle to the controller 110. The turning angle is detected up to 360 degrees, with a state in which the fore-and-aft direction of the upper turning body 12 and the fore-and-aft direction of the lower running body 14 coincide as 0 degrees, a right turn as a positive value, and a left turn as a negative value.

[0065] The anemometer 123 detects the wind direction and wind speed (both wind information) around the crane 10, and inputs a signal according to the detected information to the controller 110.

[0066] The goniometer 124 detects the boom hoisting angle and the jib 18 hoisting angle, and inputs signals corresponding to the detected angles to the controller 110. The boom hoisting angle is the relative angle of the center line of the boom 16 with respect to the horizontal plane, and the jib hoisting angle is the relative angle of the center line of the jib 18 with respect to the horizontal plane. The definitions of the hoisting angles are not limited to these.

[0067] The main body inclinometer 125 detects the inclination angle of the main body (upper rotating body 12, lower traveling body 14) of the crane 10 relative to the horizontal plane, and inputs a signal corresponding to the detected angle to the controller 110. When the crane 10 is working on a slope, for example, the main body inclinometer 125 detects a predetermined angle.

[0068] The load meter 126 detects the load of the load suspended from the tip of the jib 18 and connected to the hook 57, and inputs a signal corresponding to the detected load to the controller 110. The load meter 126 detects the load based on the tension of the rope 50, for example.

[0069] At a work site where the crane 10 is used, the upper rotating body 12 needs to be rotated at a desired rotation speed. As an example, one of the automatic operation techniques for the crane 10 is to control the rotation speed and rotation direction of the upper rotating body 12 in order to suppress the sway of a load suspended from the tip of the jib 18. Load sway is a phenomenon in which the suspended load (rope 50) sways with the tip of the jib 18 as a fulcrum. It is known that when the suspended load is swaying, the sway can be reduced by controlling the rotation operation of the upper rotating body 12.

[0070] FIG. 3 is a graph showing the relationship between the target swing speed and the proportional valve command current value. A speed map such as that shown in FIG. 3 can be used to control the swing speed as described above. Such a speed map can be obtained by hydraulic power calculation. By controlling the magnitude of the proportional valve command current value input from the controller 110 to the proportional valve 107 based on such a speed map, the flow rate of hydraulic oil supplied from the hydraulic pump 104 to the swing motor 105 is adjusted, and the swing speed of the upper swing body 12 is controlled. In this case, when the rotation speed of the engine 102 is high, the target swing speed can be obtained with a relatively small proportional current value.

[0071] The inventors of the present invention came up with the idea of ​​the present invention by noticing that when attempting to control the rotation of the upper rotating body 12 based on a preset speed map, the actual rotation speed varies due to various variable factors. Table 1 shows an example of such variable factors.

[0072] [Table 1] Factors that cause fluctuations in the rotation speed of the upper rotating body 12 are classified into internal factors (internal fluctuation factors) and external factors (external fluctuation factors). Internal factors are primarily related to the crane 10, and when multiple cranes 10 are present, the magnitude of these factors varies among the cranes 10. Specifically, influencing factors included in the internal factors include friction, valve spring variation, and proportional valve variation. Friction corresponds to the individual variation of the rotation bearing 12S (FIG. 1) and the associated reducer. Valve spring variation corresponds to the individual variation of the spring constants of the pair of springs provided corresponding to each pilot port of the control valve 106. If the spring constants differ, the opening area of ​​the control valve 106 changes even when the proportional valve command current value is the same, resulting in a change in the rotation speed of the upper rotating body 12. Furthermore, proportional valve variation is variation between individual proportional valves 107, and means that even when the same proportional valve command current value is received, the pilot pressure supplied to the pilot port of the control valve 106 differs between individual proportional valves 107.

[0073] On the other hand, external factors include wind load (wind information) and crane body inclination. Wind load refers to the load that acts on the attachment 10S due to wind generated at the work site, creating resistance to the rotation of the upper rotating body 12. When the wind volume is large, greater resistance acts on the attachment 10S. The magnitude of this resistance also varies depending on the wind direction relative to the rotation of the upper rotating body 12, i.e., the attachment 10S. Furthermore, since the magnitude of the wind load varies depending on the wind-receiving area, it also varies depending on the configuration of the attachment 10S (boom 16 only or boom 16 and jib 18), the angle of the boom 16, and the angle of the jib 18. Furthermore, crane body inclination corresponds to the inclination of the crane 10 body (upper rotating body 12, lower running body 14) at the work site. When the crane 10 operates on a given slope, the central axis of rotation of the upper rotating body 12 is tilted relative to the vertical. For this reason, gravity acting on the attachment 10S either promotes or hinders the swing operation depending on the swing position (swing angle) of the upper swing body 12, which becomes a factor in variation in the swing speed. Machine-side parameters related to the tilt of the main body include the configuration of the attachment 10S, the angle of the boom 16, and the angle of the jib 18, as well as the lifted load, which affects the centrifugal force of the attachment 10S.

[0074] As described above, various factors affect the rotation speed of the upper rotating body 12. Therefore, if the rotation speed is controlled based on a preset speed map, as shown in Figure 3, regardless of individual differences in the crane 10 or the work site environment, the target rotation speed cannot be achieved. Figure 4 is a graph showing the time progression of the target rotation speed and the actual rotation speed. As shown in Figure 4, if the proportional valve command current value is input based on the speed map of Figure 3, the actual rotation speed will be smaller than the target rotation speed due to resistance and load caused by the factors of variation. For example, when the rotation speed of the upper rotating body 12 is controlled for the purpose of load sway control, the result can be a problem of load sway not being suppressed or even being exacerbated.

[0075] In this embodiment, in order to solve the above-mentioned problems, the controller 110 of the swing control device 100 suitably controls the proportional valve command current value input to the proportional valve 107. Specifically, the controller 110 corrects a reference command signal that is set in advance corresponding to a predetermined target swing speed based on information related to fluctuation factors that cause the swing speed to fluctuate, to generate a corrected command signal, and inputs the corrected command signal to the swing drive unit 101.

[0076] In particular, in this embodiment, the controller 110 adjusts the rotation speed of the upper rotating body 12 based on the following equation 1.

[0077] I_swing=I_ideal+I_mod_in+I_mod_ext (Formula 1) In Equation 1, I_swing is the proportional valve command current value (corrected command signal) that is finally input to the proportional valve 107. I_ideal is the theoretical value of the speed map described above, and is the command current value obtained from an ideal relationship. I_mod_in is a term that corrects the internal factors described above, and I_mod_ext is a term that corrects the external factors described above.

[0078] Next, a procedure for deriving the above-mentioned I_mod_in in this embodiment will be described. Fig. 5 is a flowchart showing internal factor correction control executed by the swing control device 100 according to this embodiment. Fig. 6 is a graph showing the relationship between the target swing speed and the proportional valve command current value. Fig. 7 is a graph showing the time transition of the proportional valve command current value.

[0079] In this embodiment, as an example, before the crane 10 is shipped from the factory, with the attachment 10S detached from the upper rotating body 12, the above-mentioned I_mod_in is derived, set, and stored in the controller 110. That is, I_mod_in is set individually for each crane 10, taking into account individual differences between the cranes 10. As shown in FIG. 5, in the process of deriving I_mod_in, the controller 110 commands a predetermined target swing speed (step S1). Next, the controller 110 acquires information on the rotation speed of the engine 102 from the ECU 103 (step S2). The rotation speed of the engine 102 is set by an operator via a rotation speed setting switch provided in the cab of the crane 10. Next, the controller 110 calculates I_ideal (step S3). As an example, a speed map shown in FIG. 3 is stored in advance in the controller 110, and the controller 110 calculates I_ideal from the target swing speed and engine rotation speed in this speed map. 3 is stored in the controller 110, the vertical axis of the graph corresponds to I_ideal. I_ideal may be calculated based on the arithmetic expression representing the graph stored in the controller 110. As a result, the proportional valve command current value to be input to the proportional valve 107 is determined (step S4).

[0080] Next, the controller 110 inputs the proportional valve command current value to the proportional valve 107, opening the proportional valve 107 to rotate the swing motor 105 (step S5). As a result, the upper swing structure 12 without the attachment 10S swings relative to the lower traveling structure 14. The swing speed meter 121 then measures the actual swing speed of the upper swing structure 12 and inputs the result to the controller 110 (step S6). The controller 110 maps and stores the relationship between the received actual swing speed and the proportional valve command current value determined in step S4 (step S7). In FIG. 6, I_ideal acquired in step S3 is indicated by a dashed line, and the actual swing speed mapped in step S7 is indicated by a solid line. In other words, even when the attachment 10S is detached from the upper swing body 12, a current value greater than the ideal proportional valve command current value I_ideal is required due to internal factors such as friction, valve spring variation, and proportional valve variation. For the same target swing speed, the difference between the solid line and the dashed line in Figure 6 corresponds to I_mod_in. As a result, the controller 110 can acquire information about I_mod_in (step S8).

[0081] By obtaining I_mod_in, it is possible to set the proportional valve correction current value I_swing' taking into account internal factors based on the following equation 2.

[0082] I_swing'=I_ideal+I_mod_in (Formula 2) That is, when it is desired to rotate the upper rotating body 12 at a predetermined target rotation speed, by inputting I_swing' instead of I_ideal to the proportional valve 107, it is possible to achieve a highly accurate rotation speed while suppressing variations due to internal factors. In Fig. 7, I_ideal is indicated by a dashed line, and I_swing' is indicated by a solid line.

[0083] It is desirable to repeatedly execute the procedure in Figure 5 while changing the engine speed and the target turning speed, so that I_mod_in can be obtained with high accuracy even when these parameters change.

[0084] Next, a procedure for deriving the above-mentioned I_mod_ext in this embodiment will be described. Fig. 8 is a flowchart showing external factor correction control executed by the swing control device 100 according to this embodiment. In this embodiment, as an example, at the work site of the crane 10, with the attachment 10S attached to the upper swing body 12, the above-mentioned I_mod_ext is derived, set, and stored in the controller 110. Note that, before shipping from the factory, after the above-mentioned I_mod_in has been derived and set, the initial value of I_mod_ext may be set in a procedure similar to the following.

[0085] As shown in FIG. 8, in the process of deriving I_mod_ext, the controller 110 also commands a predetermined target swing speed (step S11). Next, the controller 110 acquires information about the configuration of the attachment 10S, which is stored in advance in a storage unit within the controller 110 (step S12). Furthermore, the controller 110 acquires information about the rotation speed of the engine 102 from the ECU 103 (step S13). Next, the controller 110 calculates I_ideal′ (step S14). As an example, a speed map that takes internal factors into account, as shown by the solid line in FIG. 6, is stored in advance in the controller 110, and the controller 110 calculates I_ideal′ from the target swing speed and engine rotation speed using this speed map. As a result, a proportional valve command current value to be input to the proportional valve 107 is determined (step S15).

[0086] Next, the controller 110 inputs the proportional valve command current value to the proportional valve 107, and opens the proportional valve 107 to rotate the swing motor 105 (step S16). As a result, the upper swing body 12 with the attachment 10S attached thereto swings relative to the lower traveling body 14. Then, the swing speed meter 121 measures the actual swing speed of the upper swing body 12 and inputs the result to the controller 110 (step S17). Similarly, information detected by the swing angle meter 122, the anemometer 123, the angle meter 124, the main body inclinometer 125, and the load meter 126 is input to the controller 110.

[0087] Here, the controller 110 transmits the following information to the server 112 via the communication device 111 (Figure 2): the target rotation speed in step S11, the attachment configuration in step S12, the actual rotation speed obtained in step S17, the wind direction, the wind speed, the angles of the boom 16 and the jib 18, the inclination of the main body of the crane 10, and the suspended load (step S18).

[0088] The server 112 updates the neural network using the acquired information as input values ​​(step S19). Here, the neural network calculates the interrelationships between the above-mentioned input parameters and accumulates information regarding the proportional valve command current value for obtaining the target swing speed when each parameter changes. Therefore, it is possible to output the optimal command current value I_opti that can obtain the target swing speed set in step S11 of FIG. 8 with the highest accuracy. The controller 110 acquires the optimal command current value I_opti input from the server 112 to the communication device 111 (step S20).

[0089] Then, the controller 110 can calculate the latest I_mod_ext by subtracting I_ideal' calculated in step S14 from the optimal command current value I_opti (step S21). That is, the optimal command current value I_opti includes I_ideal, which is a command current value obtained from an ideal relationship, I_mod_in, which is a term for correcting the internal factors described above, and I_mod_ext, which is a term for correcting the external factors described above. Therefore, I_mod_ext can be obtained by removing the part of I_ideal' that corresponds to I_ideal+I_mod_in.

[0090] The process shown in FIG. 8 is also preferably executed repeatedly while varying the engine speed, target swing speed, wind direction, wind speed, angles of the boom 16 and jib 18, inclination of the crane 10 body, and lifted load. These operations may be performed at a factory or the like before shipping. As a result, I_mod_ext can be acquired with high accuracy even when these parameters change. Therefore, even if the parameters fluctuate at the work site, the proportional valve command current value I_swing that enables the upper swing body 12 to swing at the target swing speed can be input to the proportional valve 107. Note that the proportional valve command current value I_swing may be set in accordance with at least one of the fluctuation factors, including internal and external factors.

[0091] It is also possible for the server 112 to acquire each parameter from multiple cranes 10 operating at a work site, and store and share the I_mod_ext information in the server 112. In particular, cranes 10 of the same class (specifications) may use a common I_mod_ext.

[0092] In the above embodiment, I_mod_ext, which is a term for correcting external factors, is set before the crane 10 begins work at the work site, but the present invention is not limited to this. Fig. 9 is a flowchart showing external factor correction control executed by the swing control device 100 according to a modified embodiment of the present invention. In this modified embodiment, the neural network of the server 112 stores predetermined information in advance, and after the crane 10 begins work at the work site, an appropriate proportional valve command current value I_swing is set according to each acquired parameter.

[0093] For example, the controller 110 commands a predetermined target rotation speed based on feedforward control to suppress swing of the suspended load (step S31). Next, the controller 110 acquires information about the configuration of the attachment 10S (step S32). Furthermore, the controller 110 acquires information about the rotation speed of the engine 102 from the ECU 103 (step S33).

[0094] Next, information detected by the swing angle meter 122, the anemometer 123, the angle meter 124, the main body inclinometer 125, and the load meter 126 is input to the controller 110 (step S34). The controller 110 transmits the acquired information to the server 112 (step S35). The server 112 updates the neural network using the received information as an input value (step S36), determines an optimal proportional valve command current value I_swing corresponding to the target swing speed set in step S31 (step S37), and transmits the optimal proportional valve command current value I_swing to the controller 110 via the communication device 111. The controller 110 opens the proportional valve 107 based on the proportional valve command current value I_swing, and executes the swing operation of the upper swing body 12 (step S38). At this time, the actual swing speed of the upper swing body 12 detected by the swing speed meter 121 may be transmitted from the controller 110 to the server 112, thereby updating (learning) the information of the neural network in the server 112.

[0095] As described above, in this modified embodiment, while the crane 10 is performing work at a work site, it is possible to control the rotation speed of the upper rotating body 12 with high precision and update the information in the server 112. Note that the calculation method executed by the server 112 is not limited to a neural network, and may be based on other known machine learning functions, etc.

[0096] According to each of the above embodiments, the swing control device 100 (controller 110) operates the swing drive unit 101 based on feedforward control so that the upper swing body 12 swings at a target swing speed. The controller 110 corrects a reference command signal that is set in advance corresponding to a predetermined target swing speed based on information related to fluctuation factors that cause the swing speed to fluctuate, to generate a corrected command signal, and inputs the corrected command signal to the swing drive unit 101. Therefore, it is possible to swing the upper swing body 12 at the target swing speed with high precision while suppressing variations due to fluctuation factors.

[0097] In particular, the fluctuation factors include external fluctuation factors related to the work site of the crane 10. Therefore, even if the external fluctuation factors that cause fluctuations in the rotation speed at the work site change, the upper rotating body 12 can be rotated at the target rotation speed with high precision.

[0098] The rotation control device 100 may include an anemometer 123 (wind information acquisition unit), and the controller 110 may correct the reference command signal and generate a corrected command signal based on wind information including at least one of wind volume and wind direction as external fluctuation factors. With this configuration, even if wind information changes at the work site, the upper rotating body 12 can be rotated at the target rotation speed with high precision.

[0099] Furthermore, if the swing control device 100 further includes, in addition to the anemometer 123, a swing angle meter 122 (swing angle detection unit) capable of detecting the swing angle of the upper swing structure 12 relative to the lower running structure 14, the controller 110 may correct the reference command signal and generate a corrected command signal based on the wind direction and swing angle as external factors. With this configuration, the upper swing structure 12 can be precisely rotated at a target swing speed while taking into account the load that the attachment 10S receives from the wind, depending on whether the attachment 10S supported on the upper swing structure 12 is heading from upwind to downwind or from downwind to upwind.

[0100] 2 can function as the working radius acquisition unit of the present invention. That is, if information on the lengths of the boom 16 and jib 18 is stored in advance in the controller 110, the hoisting angles of the boom 16 and jib 18 can be detected by the goniometer 124, allowing the controller 110 to calculate the working radius of the attachment 10S in a planar view. In this case, the controller 110 may correct the reference command signal and generate a corrected command signal based on the wind information and the working radius as external factors.

[0101] When the working radius of the attachment 10S is small, that is, when the attachment 10S is in a position closer to the vertical direction relative to the upper rotating body 12, the moment that the attachment 10S receives in the lateral direction from the wind is small. On the other hand, when the working radius of the attachment 10S is large, that is, when the attachment 10S is in a position where it is significantly tilted relative to the upper rotating body 12, the moment that the attachment 10S receives in the lateral direction from the wind becomes relatively large. Therefore, the controller 110 generates a corrected command signal taking into account the working radius of the attachment 10S and the moment that the attachment 10S receives in the lateral direction (the lateral direction of the upper rotating body 12) from the wind, and can rotate the upper rotating body 12 with high precision at the target swing speed.

[0102] Furthermore, if the controller 110 includes a main body inclinometer 125 (tilt detection unit), the controller 110 may correct the reference command signal and generate a corrected command signal based on the tilt angle of the upper rotating body 12 with respect to the horizontal plane as an external factor. With this configuration, the upper rotating body 12 can be rotated accurately at a target rotation speed while taking into account the effect of gravity on the attachment 10S supported by the upper rotating body 12 in accordance with the tilt of the work site.

[0103] Furthermore, if the controller 110 includes a rotation angle meter 122 in addition to the main body inclinometer 125 (tilt detection unit), the controller 110 may correct the reference command signal and generate a corrected command signal based on the tilt angle of the upper rotating body 12 with respect to the horizontal plane and the rotation angle of the upper rotating body 12 as external factors. With this configuration, a corrected command signal is generated taking into account the influence of gravity on the attachment 10S depending on whether the attachment 10S supported on the upper rotating body 12 is heading up the slope or down the slope, and the upper rotating body 12 can be rotated accurately at a target rotation speed.

[0104] Furthermore, in the case where the controller 110 includes the main body inclinometer 125 as described above, and if the information related to the working radius can be calculated and acquired, the controller 110 may correct the reference command signal based on the tilt angle and working radius as external factors to generate a corrected command signal. With this configuration, a corrected command signal is generated taking into account the effect of gravity depending on the slope of the work site and the resulting lateral moment that the attachment 10S actually receives, thereby enabling the upper rotating body 12 to rotate accurately at a target rotation speed.

[0105] Furthermore, if the controller 110 includes the load meter 126, the controller 110 may correct the reference command signal and generate a corrected command signal based on the lifting load as an external factor. With this configuration, a corrected command signal is generated taking into account the load that the lifting load imparts to the rotation operation of the upper rotating body 12, and the upper rotating body 12 can be rotated at a target rotation speed with high precision.

[0106] The fluctuation factors may also include internal factors related to the crane 10. In such a case, even if the internal factors change at the work site, the upper rotating body 12 can be rotated at the target rotation speed with high precision.

[0107] In particular, in this embodiment, the internal factors include factors that change the rotation speed of the upper rotating body 12 in a disconnected state. The disconnected state is a state in which the attachment 10S is detached from the upper rotating body 12. With this configuration, the upper rotating body 12 can be rotated accurately at a target rotation speed when the attachment 10S is attached to the upper rotating body 12, taking into account variable factors that occur when the upper rotating body 12 without the attachment 10S rotates relative to the undercarriage 14. In other words, when the upper rotating body 12 without the attachment 10S attached rotates relative to the undercarriage 14, the rotation speed of the upper rotating body 12 can be set to the target rotation speed, taking into account tolerances of the slewing bearing 12S (FIG. 1) and the reducer connected thereto, individual variations, and the like.

[0108] Furthermore, in this embodiment, the swing drive unit 101 has a swing motor 105 and a valve mechanism (control valve 106, proportional valve 107) that opens to change the flow rate of hydraulic oil supplied to the swing motor 105 in response to an input command signal. Therefore, by optimizing the command signal (proportional valve command current value) that the controller 110 inputs to the valve mechanism, the swing speed of the upper swing body 12 can be stably set to the target swing speed.

[0109] In this embodiment, the controller 110 (server 112) receives information about the fluctuation factors and corrects I_ideal (reference command signal) using a neural network. Therefore, even under conditions requiring advanced calculations in which multiple parameters change, it is possible to obtain an optimal corrected command signal taking into account the influence of each parameter.

[0110] The above describes the swing control device 100 and the crane 10 equipped with the same according to each embodiment of the present invention. However, the present invention is not limited to these embodiments. For example, the present invention can take the following modified embodiments.

[0111] (1) In the above embodiment, the controller 110 sets the command signal to the proportional valve 107 taking into consideration both the internal and external factors in Table 1. However, the present invention is not limited to this. The controller 110 may set the command signal based on any of the fluctuation factors. Furthermore, the fluctuation factors are not limited to those listed in Table 1.

[0112] (2) Furthermore, the crane 10 shown in FIG. 1 may not have the rear strut 21 or the front strut 22, or may have only one strut. The structure of the mast supporting the boom 16 is not limited to that shown in FIG. 1 and may be another mast structure or a gantry structure (not shown). Furthermore, the crane 10 may not have the jib 18. Furthermore, the lower body supporting the upper rotating body 12 is not limited to the travelable lower running body 14 and may be a fixed type. Furthermore, the work machine according to the present invention is not limited to the crane 10 and may be another work machine having an upper rotating body that rotates relative to the lower body. [Explanation of symbols]

[0113] 10 Crane 100 Turning control device 101 Swivel drive unit 102 Engine 103 ECU 104 Hydraulic pump 105 Swivel motor 106 Control valve (valve mechanism) 107 Proportional valve (valve mechanism) 10S Attachment 110 Controller 111 Communication equipment 112 servers 121 Turning speed meter 122 Turning angle meter (turning angle detection unit) 123 Anemometer (wind information acquisition part) 124 Angle meter (working radius acquisition part) 125 Main body inclinometer (tilt detection unit) 126 Load meter (load detection unit) 12 Upper rotating body 14 Lower running body (lower body) 16. Boom 18 Jib

Claims

1. A lower body and an upper rotating body rotatably supported on the lower body; a rotation drive unit that rotates the upper rotating body with a driving force corresponding to the magnitude of an input command signal; an attachment supported on the upper rotating body so as to be rotatable in a hoisting direction; A swing control device for a work machine having A swing control device for a work machine, comprising: a controller that operates the swing drive unit based on feedforward control so that the upper swing body swings at a predetermined target swing speed, corrects a reference command signal that is set in advance corresponding to the target swing speed based on information related to fluctuation factors that cause fluctuations in the swing speed to generate a corrected command signal, and inputs the corrected command signal to the swing drive unit.

2. The swing control device for a work machine according to claim 1 , wherein the fluctuation factors include external fluctuation factors related to a work site of the work machine.

3. a wind information acquisition unit capable of acquiring wind information including at least one of wind volume and wind direction at the work site; The swing control device for a work machine according to claim 2 , wherein the external fluctuation factors include the wind information.

4. Further provided is a rotation angle detection unit capable of detecting a rotation angle of the upper rotating body relative to the lower main body, the wind information includes the wind direction; The swing control device for a work machine according to claim 3 , wherein the controller corrects the reference command signal based on at least the wind direction and the swing angle.

5. Further, a working radius acquisition unit capable of acquiring information regarding the working radius of the attachment is provided, The turning control device for a work machine according to claim 3 or 4, wherein the controller corrects the reference command signal based on at least the wind information and the working radius.

6. Further provided is an inclination detection unit capable of detecting an inclination angle of the upper rotating body relative to a horizontal plane at the work site, The turning control device for a work machine according to claim 2 , wherein the external fluctuation factors include the tilt angle.

7. Further provided is a rotation angle detection unit capable of detecting a rotation angle of the upper rotating body relative to the lower main body, The swing control device for a work machine according to claim 6, wherein the controller corrects the reference command signal based on at least the tilt angle and the swing angle.

8. Further, a working radius acquisition unit capable of acquiring information regarding the working radius of the attachment is provided, The swing control device for a work machine according to claim 6 or 7, wherein the controller corrects the reference command signal based on at least the tilt angle and the working radius.

9. Further provided is a load detection unit capable of detecting the load of a load suspended from the tip end of the attachment, The swing control device for a work machine according to any one of claims 1 to 8, wherein the controller corrects the reference command signal based on at least the load.

10. The swing control device for a work machine according to any one of claims 1 to 9, wherein the fluctuation factors include internal fluctuation factors related to the work machine.

11. the internal fluctuation factor includes a factor that changes the rotation speed of the upper rotating body in a disconnected state, The swing control device for a work machine according to claim 10, wherein the disconnected state is a state in which the attachment is detached from the upper swing body.

12. The turning drive unit is a rotation motor that receives hydraulic oil and rotates to rotate the upper rotating body; a valve mechanism that opens to change the flow rate of hydraulic oil supplied to the swing motor in response to the input command signal; The swing control device for a work machine according to any one of claims 1 to 11, comprising:

13. 13. The swing control device for a work machine according to claim 1, wherein the controller receives information relating to the fluctuation factors and corrects the reference command signal using a neural network.

14. A lower body and an upper rotating body rotatably supported on the lower body; a rotation drive unit that rotates the upper rotating body with a driving force corresponding to the magnitude of an input command signal; an attachment supported on the upper rotating body so as to be rotatable in a hoisting direction; A swing control device for a work machine according to any one of claims 1 to 13; A work machine comprising:

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