crane

Abstract

This disclosure provides a crane capable of suppressing the swing of a suspended load when the slewing is stopped. [Solution] The crane comprises an upper slewing body that is rotatable, an attachment that is rakeable on the upper slewing body, and a hook that is suspended via the attachment so as to be able to move up and down. The crane also includes a controller that controls the rotational angular acceleration of the upper slewing body based on an angular acceleration waveform AW1 that suppresses the swing of the hook, in a rotation stop control that automatically stops the rotation of the upper slewing body. The angular acceleration waveform AW1 includes a first period T1 in which the angular acceleration decreases from zero at a constant first rate of change j1, and a final period Tf in which, after a predetermined period has elapsed from the first period T1, the angular acceleration increases at a rate of change -j1 that is the opposite of the first rate of change j1, and the angular acceleration becomes zero.

Description

[Technical Field]

[0001] This disclosure relates to cranes. [Background technology]

[0002] Conventionally, safety devices for controlling the stopping of slewing in construction machinery such as cranes are known (see Patent Document 1 below). The conventional safety device described in Patent Document 1 calculates the required angle to brake and stop the slewing without leaving any swing of the suspended load, and the remaining angle at which the slewing can continue until the lifting load reaches the rated load, and initiates slewing braking based on a comparison of these angles. [Prior art documents] [Patent Documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 5-116892 [Overview of the project] [Problems that the invention aims to solve]

[0004] The conventional safety device described above cannot initiate turning braking if it cannot calculate the required angle.

[0005] This disclosure provides a crane capable of suppressing the swing of a suspended load when the slewing is stopped. [Means for solving the problem]

[0006] Embodiments of the present disclosure provide a crane comprising: an upper slewing body provided to be rotatable; an attachment provided to be up and down on the upper slewing body; a hook suspended via the attachment so as to be able to move up and down; and a controller that controls the rotational angular acceleration of the upper slewing body based on an angular acceleration waveform that suppresses the swing of the hook, wherein the angular acceleration waveform includes a first period in which the angular acceleration decreases from zero at a constant first rate of change, and a final period in which, after a predetermined period has elapsed from the first period, the angular acceleration increases at a rate of change that is the opposite of the first rate of change, and the angular acceleration becomes zero. [Effects of the Invention]

[0007] According to embodiments of this disclosure, a crane capable of suppressing the swing of a suspended load when the slewing is stopped can be provided. [Brief explanation of the drawing]

[0008] [Figure 1] This is a side view showing an embodiment of the crane related to this disclosure. [Figure 2] This is a top view of the upper rotating body of a crane according to an embodiment of the present disclosure. [Figure 3] This is a side view showing the tower specifications of a crane according to an embodiment of the present disclosure. [Figure 4] This is a perspective view of the interior of the operator's cab of a crane according to an embodiment of this disclosure. [Figure 5] This is a block diagram of the hydraulic drive system of a crane according to an embodiment of the present disclosure. [Figure 6] This is a functional block diagram of a crane according to an embodiment of the present disclosure. [Figure 7] This is a flowchart showing an example of crane processing according to the embodiment of this disclosure. [Figure 8] This figure shows an example of the angular acceleration waveform of a crane according to an embodiment of the present disclosure. [Figure 9] This figure shows an example of the angular acceleration waveform of a crane according to an embodiment of the present disclosure. [Figure 10]It is a diagram showing an example of the angular acceleration waveform of a crane according to an embodiment of the present disclosure. [Figure 11] It is a diagram showing the stop time of the swing of the suspended load and the maximum value of the swing angle in this embodiment. [Figure 12] It is a diagram showing a comparison of the angular acceleration waveforms of Example 1 and Comparative Example 1 according to the present disclosure. [Figure 13] It is a diagram showing a comparison of the angular acceleration waveforms of Example 2 and Comparative Example 2 according to the present disclosure. [Figure 14] It is a diagram showing an example of the swing of the suspended load of the crane according to an embodiment of the present disclosure.

Mode for Carrying Out the Invention

[0009] Hereinafter, embodiments of the crane according to the present disclosure will be described with reference to the drawings.

[0010] The embodiments described below are illustrative and do not limit the invention. Not all features and combinations thereof in the embodiments of the present disclosure are necessarily essential to the invention. In each drawing, the same or corresponding components are denoted by the same or corresponding reference numerals, and redundant descriptions may be omitted.

[0011] FIG. 1 is a side view showing a crane 1 according to an embodiment of the present disclosure. The crane 1 includes, for example, a lower traveling body 2, an upper slewing body 3, and an attachment AT. The crane 1 shown in FIG. 1 is a mobile crane of a crane specification including a lower boom 61, an intermediate boom 62, and an upper boom 63 as the attachment AT.

[0012] The lower traveling body 2 includes, for example, left and right crawlers 21 and left and right traveling devices 22. The crawler 21 is driven by the traveling device 22 and rotates back and forth. The traveling device 22 is a hydraulic actuator including a traveling hydraulic motor driven by the hydraulic pressure of hydraulic oil, and the crane 1 is caused to travel back and forth by rotating the crawler 21 back and forth.

[0013] The upper rotating body 3 is rotatably mounted on the lower traveling body 2. The upper rotating body 3 also has a driver's cab 4 located to the side of the attachment AT.

[0014] Figure 2 is a top view of the upper slewing body 3 of the crane 1 shown in Figure 1. Note that in Figure 2, some components of the crane 1 shown in Figure 1, such as the attachment AT, are not shown. As shown in Figure 2, the upper slewing body 3 has, for example, a slewing frame 31 and beds 32, 33. Specifically, the upper slewing body 3 has a slewing frame 31 that is rotatably mounted on the lower traveling body 2, and left and right beds 32, 33 connected to both sides of the slewing frame 31.

[0015] The slewing frame 31 is equipped with a slewing device 35 at its front end and a counterweight 36 at its rear end. The slewing frame 31 is also equipped with, for example, a front winch 37f, a rear winch 37r, a third winch 37t, and a boom luffing winch 37b. However, the crane 1 does not necessarily have to have a third winch 37t.

[0016] The slewing device 35 is, for example, a hydraulic actuator including a slewing motor driven by hydraulic pressure of a hydraulic fluid, which slewingly rotates a slewing frame 31, which is slewingly attached to the lower traveling body 2, relative to the lower traveling body 2. The counterweight 36 can be, for example, a fabricated metal counterweight or a cast metal counterweight.

[0017] The front winch 37f, rear winch 37r, third winch 37t, and boom luffing winch 37b are hydraulic actuators, including a hydraulic motor driven by hydraulic pressure from a hydraulic fluid. These winches wind up the front drum wire rope 83, rear drum wire rope 85, boom luffing wire rope 69, etc., as shown in Figure 1.

[0018] The left bed 32 is connected to the left side of the slewing frame 31 and constitutes the left side of the upper slewing body 3. The right bed 33 is connected to the right side of the slewing frame 31 and constitutes the right side of the upper slewing body 3. In the example shown in Figure 2, the right bed 33 is located on the side of the upper slewing body 3 where the driver's cab 4 is provided. The left and right beds 32 and 33 are provided with houses 5 for housing various equipment mounted on the upper slewing body 3.

[0019] House 5 has a removable left cover 51L that covers electrical equipment and other items mounted on the left bed 32. House 5 also has a removable right cover 51R that covers various devices mounted on the right bed 33, for example.

[0020] The driver's cab 4 is located, for example, at the front end of the right bed 33 and to the right of the attachment AT. The driver's cab 4 is also called a cabin or cab. Alternatively, the driver's cab 4 may be located at the front end of the left bed 32 and to the left of the attachment AT.

[0021] The attachment AT is mounted on the upper slewing body 3 so as to be able to raise and lower. Specifically, the attachment AT is attached to the front end of the slewing frame 31, for example, via a boom foot pin parallel to the width direction of the upper slewing body 3. In the crane 1 of the crane specifications shown in Figure 1, the attachment AT includes a lower boom 61, an intermediate boom 62, and an upper boom 63.

[0022] The lower boom 61 is mounted to the slewing frame 31 of the upper slewing body 3 so as to be rotatable forward and backward. The intermediate boom 62 is mounted to the tip of the lower boom 61. The upper boom 63 has guide sheaves 64 and auxiliary sheaves 65 and is mounted to the tip of the intermediate boom 62. The height of the attachment AT can be changed by increasing or decreasing the number of intermediate booms 62 between the lower boom 61 and the upper boom 63.

[0023] Furthermore, the crane 1 shown in Figure 1 has a pendant rope 66, an upper spreader 67, a lower spreader 68, a boom luffing wire rope 69, a gantry 71, a gantry lifting cylinder 72, and a backstop 73.

[0024] The pendant rope 66 has one end connected to the rear of the tip of the upper boom 63 and the other end connected to the upper spreader 67. The lower spreader 68 is attached to the tip of the gantry 71, which is mounted on the slewing frame 31 so as to be luffable. The gantry lifting cylinder 72 is mounted on the slewing frame 31 and luffs the gantry 71. The boom luffing wire rope 69 is stretched between the upper spreader 67 and the lower spreader 68 and is wound around the boom luffing winch 37b.

[0025] With the gantry 71 raised by the gantry lifting cylinder 72, the boom luffing winch 37b can be used to wind up the boom luffing wire rope 69, thereby rotating the attachment AT backward and upward to raise it. At this time, the backstop 73 restricts the backward rotation of the attachment AT. Furthermore, by unwinding the boom luffing wire rope 69 with the boom luffing winch 37b, the attachment AT can be rotated forward and downward to tilt it forward.

[0026] Furthermore, the crane 1 shown in Figure 1 has a boom hook 81, a jib hook 82, a front drum wire rope 83, a hook overwinding prevention device 84, and a rear drum wire rope 85.

[0027] The front drum wire rope 83 is stretched across the boom hook 81 and wound around the front winch 37f. A hook overwinding prevention device 84 is provided on the front drum wire rope 83. The rear drum wire rope 85 is connected to the jib hook 82 and wound around the rear winch 37r.

[0028] By winding up the front drum wire rope 83 with the front winch 37f, the boom hook 81 can be raised to lift the load. At this time, the hook overwinding prevention device 84 prevents the boom hook 81 from being wound up excessively. Conversely, by unwinding the front drum wire rope 83 with the front winch 37f, the boom hook 81 can be lowered to lower the load.

[0029] Similarly, the jib hook 82 can be raised and the load lifted by winding up the rear drum wire rope 85 with the rear winch 37r. Conversely, the jib hook 82 can be lowered and the load lowered by unwinding the rear drum wire rope 85 with the rear winch 37r.

[0030] Figure 3 is a side view showing the tower configuration of crane 1 in Figure 1. In the tower configuration of crane 1, attachment AT includes a lower tower boom 61t, an intermediate tower boom 62t, an upper tower boom 63t, a lower tower jib 61j, an intermediate tower jib 62j, and an upper tower jib 63j.

[0031] The lower tower boom 61t is mounted to the slewing frame 31 of the upper slewing body 3 so as to be rotatable forward and backward. The intermediate tower boom 62t is mounted to the tip of the lower tower boom 61t. The upper tower boom 63t has tower struts 63ts and is mounted to the tip of the intermediate tower boom 62t. The height of the attachment AT can be changed by increasing or decreasing the number of intermediate tower booms 62t between the lower tower boom 61t and the upper tower boom 63t.

[0032] The lower tower jib 61j has a tower jib backstop 61js and is mounted to the upper tower boom 63t in a luffable manner. The intermediate tower jib 62j is mounted to the tip of the lower tower jib 61j. The upper tower jib 63j is mounted to the tip of the intermediate tower jib 62j.

[0033] Furthermore, the tower-type crane 1 shown in Figure 3 has a tower jib pendant rope 66j, a tower jib upper spreader 67j, a tower jib lower spreader 68j, and a tower jib luffing wire rope 69j.

[0034] The tower jib pendant rope 66j is stretched between the tip of the upper tower jib 63j and the tower strut 63ts, and between the tower strut 63ts and the upper tower jib spreader 67j. The lower tower jib spreader 68j is attached to the rear of the intermediate tower boom 62t, which is connected to the tip of the lower tower boom 61t. The tower jib luffing wire rope 69j is stretched between the upper tower jib spreader 67j and the lower tower jib spreader 68j and is wound around the rear winch 37r.

[0035] By winding up the tower jib luffing wire rope 69j with the rear winch 37r, the tower jib, including the lower tower jib 61j, intermediate tower jib 62j, and upper tower jib 63j, rotates rearward and upward relative to the tower boom, including the lower tower boom 61t, intermediate tower boom 62t, and upper tower boom 63t, and stands upright. At this time, the rearward rotation of the tower jib is restricted by the tower jib backstop 61js. Also, by unwinding the tower jib luffing wire rope 69j with the rear winch 37r, the tower jib rotates forward and downward.

[0036] Furthermore, the tower-type crane 1 shown in Figure 3 has a tower pendant rope 66t, a tower upper spreader 67t, a tower lower spreader 68t, and a tower luffing wire rope 69t.

[0037] The tower pendant rope 66t has one end connected to the rear of the upper tower boom 63t and the other end connected to the upper tower spreader 67t. The lower tower spreader 68t is attached to the tip of the gantry 71, which is provided on the slewing frame 31 so as to be able to luff. The tower luffing wire rope 69t is stretched between the upper tower spreader 67t and the lower tower spreader 68t and is wound around the boom luffing winch 37b.

[0038] With the gantry 71 raised by the gantry lifting cylinder 72, the attachment AT can be rotated backward and upward by winding up the tower luffing wire rope 69t with the boom luffing winch 37b, thereby raising it to an upright position. At this time, the backward rotation of the attachment AT is restricted by the backstop 73. Furthermore, by unwinding the tower luffing wire rope 69t with the boom luffing winch 37b, the attachment AT can be rotated forward and downward, thereby tilting it forward.

[0039] Furthermore, the tower-type crane 1 shown in Figure 3, like the crane-type crane 1 shown in Figure 1, has a boom hook 81, a front drum wire rope 83, and a hook overwinding prevention device 84. This allows the boom hook 81 to be raised and the load lifted by winding up the front drum wire rope 83 with the front winch 37f. At this time, the hook overwinding prevention device 84 prevents excessive winding of the boom hook 81. Also, the boom hook 81 can be lowered and the load lowered by unwinding the front drum wire rope 83 with the front winch 37f.

[0040] Figure 4 is a perspective view of the interior of the operator's cab 4 of the crane 1 shown in Figures 1 to 3. Inside the operator's cab 4 is an operator's seat 41 where the operator of the crane 1 sits. In this embodiment, the front-to-back, left-to-right, and up-and-down directions of the crane 1 are, for example, the front-to-back, left-to-right, and up-and-down directions as seen from the perspective of the operator seated in the operator's seat 41. Various operating devices for operating the crane 1 are provided around the operator's seat 41.

[0041] Specifically, the operating device of crane 1 includes, for example, a display device 42, a switch panel 43, a slewing lever 44s, a front winch operating lever 44f, a rear winch operating lever 44r, and a boom luffing winch operating lever 44b. The operating device of crane 1 also includes, for example, a slewing brake pedal 45s, a front winch brake pedal 45f, a rear winch brake pedal 45r, a left travel lever 46L, and a right travel lever 46R.

[0042] The display device 42, for example, includes a touch panel and displays images of the area around the crane 1 and information regarding overload prevention. The switch panel 43 accepts various operations from the operator. The slewing operation lever 44s is used to operate the slewing mechanism 35 to rotate the upper slewing body 3.

[0043] The front winch control lever 44f is used to raise and lower the boom hook 81 using the front winch 37f. The rear winch control lever 44r is used to raise and lower the jib hook 82 using the rear winch 37r, and to luff the tower jib in the tower-type attachment AT. The boom luffing winch control lever 44b is used to luff the lower boom 61, intermediate boom 62, and upper boom 63, or the lower tower boom 61t, intermediate tower boom 62t, and upper tower boom 63t.

[0044] The front winch operating lever 44f and the rear winch operating lever 44r may each have a changeover switch 44fs and a changeover switch 44rs. The changeover switch 44fs of the front winch operating lever 44f is used to switch the brake mode of the front winch 37f, and the changeover switch 44rs of the rear winch operating lever 44r is used to switch the brake mode of the rear winch 37r.

[0045] The slewing brake pedal 45s is used to brake the slewing of the upper slewing body 3. The front winch brake pedal 45f is used to brake the rotation of the front winch 37f when lowering the boom hook 81 while freeing the rotation of the front winch 37f. The rear winch brake pedal 45r is used to brake the rotation of the rear winch 37r when lowering the jib hook 82 while freeing the rotation of the rear winch 37r. The left travel lever 46L is used to operate the left travel device 22 that makes up the lower travel body 2. The right travel lever 46R is used to operate the right travel device 22 that makes up the lower travel body 2.

[0046] Figure 5 is a block diagram of the hydraulic drive and control systems of crane 1 shown in Figures 1 to 4. In Figure 5, double lines indicate the transmission of mechanical power, and solid lines indicate the high-pressure hydraulic path. Dashed lines indicate the transmission path of pilot pressure, and dotted lines indicate the transmission paths of electrical signals and control signals.

[0047] The hydraulic drive system of crane 1 is equipped with hydraulic actuators that drive the lower traveling body 2, the upper slewing body 3, the attachment AT, the boom hook 81, and the jib hook 82, etc. Specifically, the hydraulic actuators of crane 1 include, for example, the left traveling motor 2ML, the right traveling motor 2MR, the slewing motor 3A, the front motor 3Mf, the rear motor 3Mr, the third motor 3Mt, and the boom luffing motor 3Mb.

[0048] The left travel motor 2ML is incorporated into the left travel device 22 of the lower travel body 2 and generates power to rotate the left crawler 21 back and forth. The right travel motor 2MR is incorporated into the right travel device 22 of the lower travel body 2 and generates power to rotate the right crawler 21 back and forth. The slewing motor 3A is incorporated into the slewing device 35 shown in Figure 2 and generates power to slewing the upper slewing body 3 relative to the lower travel body 2.

[0049] The front motor 3Mf is incorporated into the front winch 37f shown in Figure 2. The front motor 3Mf generates power to raise or lower the boom hook 81 by winding up or unwinding the front drum wire rope 83.

[0050] The rear motor 3Mr is incorporated into the rear winch 37r shown in Figure 2. In the crane configuration crane 1 shown in Figure 1, the rear motor 3Mr generates power to raise or lower the jib hook 82 by winding up or unwinding the rear drum wire rope 85. In the tower configuration crane 1 shown in Figure 3, the rear motor 3Mr generates power to raise or lower the attachment AT, which includes the tower boom and tower jib, by winding up or unwinding the tower jib luffing wire rope 69j.

[0051] The third motor 3Mt is incorporated into the third winch 37t shown in Figure 2 and generates power to wind up or unwind the wire rope wound around the third winch 37t.

[0052] The boom luffing motor 3Mb is integrated into the boom luffing winch 37b shown in Figure 2. The boom luffing motor 3Mb generates power to raise or lower the attachment AT, which includes the lower boom 61, intermediate boom 62, and upper boom 63, by winding up or unwinding the boom luffing wire rope 69 in the crane configuration shown in Figure 1.

[0053] Furthermore, the hydraulic drive system of crane 1 includes a power source 11, a main pump 12, a control valve unit 13, a pilot pump 14, and a proportional control valve 15. Furthermore, the control system of crane 1 includes a controller 10, a regulator 16, an operating device OD, an operating sensor 17, and a discharge pressure sensor 18.

[0054] The power source 11 is the main power source in the hydraulic drive system and is mounted, for example, at the rear of the upper slewing body 3. Specifically, the power source 11 rotates at a constant speed at a preset target rotational speed under direct or indirect control by the controller 10, driving the main pump 12 and the pilot pump 14. The power source 11 is, for example, an engine. Specifically, the power source 11 is, for example, a diesel engine that uses light oil as fuel. The power source 11 may also be a gasoline engine or a hydrogen engine, etc. Furthermore, the power source 11 may be a combination of a power source such as a battery or fuel cell and an electric motor.

[0055] The main pump 12 is mounted, for example, at the rear of the upper slewing body 3, similar to the power source 11. The main pump 12 is a hydraulic pump that supplies hydraulic fluid to the control valve unit 13 through the high-pressure hydraulic line 19. The main pump 12 is driven by the power source 11, as described above. The main pump 12 is, for example, a variable displacement hydraulic pump. As described above, under the control of the controller 10, the piston stroke length of the main pump 12 can be adjusted by adjusting the tilt angle of the swash plate by the regulator 16, thereby controlling the discharge volume or discharge pressure.

[0056] The control valve unit 13 is a hydraulic control device that controls the hydraulic system in the crane 1. In this embodiment, the control valve unit 13 includes control valves 131-137. The control valve unit 13 is configured to selectively supply the hydraulic fluid discharged by the main pump 12 to one or more hydraulic actuators through the control valves 131-137.

[0057] Control valves 131-137 control the flow rate of hydraulic fluid from the main pump 12 to the hydraulic actuator, and the flow rate of hydraulic fluid from the hydraulic actuator to the hydraulic fluid tank. More specifically, control valve 131 corresponds to the left travel motor 2ML, control valve 132 to the right travel motor 2MR, and control valve 133 to the slewing motor 3A. Additionally, control valve 134 corresponds to the front motor 3Mf, control valve 135 to the rear motor 3Mr, control valve 136 to the third motor 3Mt, and control valve 137 to the boom luffing motor 3Mb.

[0058] The pilot pump 14 is an example of a pilot pressure generating device and is configured to supply hydraulic fluid to hydraulic control equipment via a pilot line. In this embodiment, the pilot pump 14 is a fixed-displacement hydraulic pump. The pilot pressure generating device may also be implemented by the main pump 12. That is, the main pump 12 may have the function of supplying hydraulic fluid to the control valve unit 13 via a hydraulic fluid line, as well as the function of supplying hydraulic fluid to various hydraulic control equipment via a pilot line. In this case, the pilot pump 14 may be omitted.

[0059] The proportional control valve 15 functions as a control valve for machine control. The proportional control valve 15 is located in the pipeline connecting the pilot pump 14 and the pilot ports of the control valves 131-137 in the control valve unit 13, and is configured to change the flow area of ​​the pipeline. In this embodiment, the proportional control valve 15 operates in response to control commands output by the controller 10. Therefore, the controller 10 can supply the hydraulic fluid discharged by the pilot pump 14 to the pilot ports of the control valves 131-137 in the control valve unit 13 via the proportional control valve 15, independently of the operator's operation of the operating device OD.

[0060] This configuration allows the controller 10 to operate the hydraulic actuator corresponding to a specific operating device OD even when no operation is being performed on that specific operating device OD. Furthermore, if the crane 1 does not have machine control or remote control functions, the crane 1 does not need to have a proportional control valve 15.

[0061] The regulator 16 controls the discharge volume of the main pump 12, which is a hydraulic pump. The regulator 16 controls the discharge volume of the hydraulic fluid by the main pump 12 by adjusting the angle of the swash plate of the main pump 12, i.e., the tilt angle, in response to a control command from the controller 10.

[0062] The operating device OD is a device used by the operator to operate the actuator. The operating device OD includes, for example, the slewing lever 44s, the front winch operating lever 44f, the rear winch operating lever 44r, and the boom luffing winch operating lever 44b shown in Figure 4. The operating device OD also includes, for example, the slewing brake pedal 45s, the front winch brake pedal 45f, the rear winch brake pedal 45r, the left travel lever 46L, and the right travel lever 46R.

[0063] The operation sensor 17 is configured to detect the operator's actions using the operation device OD. In this embodiment, the operation sensor 17 detects the operating direction and amount of operation of the operation device OD corresponding to each actuator, and outputs the detected values ​​to the controller 10.

[0064] The discharge pressure sensor 18 is configured to detect the discharge pressure of the main pump 12. In this embodiment, the discharge pressure sensor 18 outputs a signal to the controller 10 corresponding to the detected discharge pressure of the main pump 12.

[0065] The controller 10 is, for example, a control device installed in the operator's cab 4 that controls the drive of the crane 1. The controller 10 includes, for example, an auxiliary storage device 10A such as ROM (Read-Only Memory), a processing device 10B such as a CPU (Central Processing Unit), a memory device 10C such as RAM (Random Access Memory), and an interface device 10D that communicates with other devices. The controller 10 is, for example, a controller that controls various parts of the crane 1. The controller 10 may consist of one controller or may consist of multiple controllers.

[0066] The controller 10 controls the opening area of ​​the proportional control valve 15 according to the output of the operation sensor 17. The controller 10 then supplies the hydraulic fluid discharged by the pilot pump 14 to the pilot ports of the corresponding control valves 131-137 in the control valve unit 13. The pressure of the hydraulic fluid supplied to each pilot port (pilot pressure) is, in principle, the pressure corresponding to the operating direction and amount of the operation sensor 17 corresponding to each hydraulic actuator. In this way, the operating device OD is configured to supply the hydraulic fluid discharged by the pilot pump 14 to the pilot ports of the corresponding control valves 131-137 in the control valve unit 13.

[0067] Furthermore, the control system of crane 1 includes, for example, a slewing sensor S1, a boom luffing sensor S2, a tower jib luffing sensor S3, a length sensor S4, a swing sensor S5, a positioning device PS, a display device D1, an input device D2, and a communication device CD.

[0068] The rotation sensor S1 outputs information regarding the rotation of the upper rotating body 3. The rotation sensor S1 detects, for example, the rotational angular velocity and rotational angular acceleration of the upper rotating body 3 relative to the lower traveling body 2. The rotation sensor S1 also detects the rotation angle. The rotation sensor S1 can be, for example, a gyro sensor, resolver, rotary encoder, or IMU (Inertial Measurement Unit). The signals corresponding to the rotation angle, rotational angular velocity, or rotational angular acceleration of the upper rotating body 3 detected by the rotation sensor S1 are input to the controller 10.

[0069] The boom luffing sensor S2 detects the luffing angle of the lower boom 61 or lower tower boom 61t, i.e., the tilt angle relative to the upper slewing body 3. The boom luffing sensor S2 can be, for example, a gyro sensor, resolver, rotary encoder, or IMU. The signal corresponding to the luffing angle of the lower boom 61 or lower tower boom 61t detected by the boom luffing sensor S2 is input to the controller 10.

[0070] The tower jib luffing sensor S3 detects the luffing angle of the lower tower jib 61j, that is, the inclination angle of the lower tower jib 61j relative to the upper tower boom 63t. The tower jib luffing sensor S3 can be, for example, a gyro sensor, resolver, rotary encoder, or IMU. The signal corresponding to the luffing angle of the lower tower jib 61j detected by the tower jib luffing sensor S3 is input to the controller 10.

[0071] The length sensor S4 detects the length of wire ropes such as the front drum wire rope 83 and rear drum wire rope 85 hanging from the sheave at the tip of the attachment AT. The length sensor S4 can use, for example, a gyro sensor, resolver, rotary encoder, and IMU to detect the rotation of the drums of the front winch 37f and support member 38r. Alternatively, the length sensor S4 can use, for example, a distance sensor to detect the distance from the sheave at the tip of the attachment AT to hooks such as the boom hook 81 and jib hook 82. The signal corresponding to the wire rope length detected by the length sensor S4 is input to the controller 10.

[0072] The swing sensor S5 detects the swing angle and angular velocity of the hooks of the crane 1, such as the boom hook 81 and the jib hook 82. The swing sensor S5 can be configured, for example, as a gyro sensor attached to the hook, or as an imaging device attached to the tip of the attachment AT. The signals corresponding to the swing angle and angular velocity of the hook detected by the swing sensor S5 are input to the controller 10.

[0073] The positioning device PS is configured to acquire information regarding the position of crane 1. In this embodiment, the positioning device PS is configured to measure the position and orientation of crane 1. Specifically, the positioning device PS is a GNSS (Global Navigation Satellite System) receiver incorporating an electronic compass, and measures the latitude, longitude, and altitude of the current position of crane 1, as well as the orientation of crane 1.

[0074] The display device D1 is installed in a location easily visible to a seated operator in the driver's cab 4 and displays various information images under the control of the controller 10. The display device D1 includes, for example, the display device 42 shown in Figure 4. The display device D1 may be connected to the controller 10 via an in-vehicle communication network such as CAN (Controller Area Network), or it may be connected to the controller 10 via a one-to-one dedicated line. Furthermore, the display device D1 is not limited to the display device 42 pre-installed in the driver's cab 4, but may also be a detachable monitor. In addition, the display device D1 may be, for example, a portable information terminal such as a tablet PC (Personal Computer) that can communicate with the communication device CD.

[0075] The input device D2 is located within reach of a seated operator in the driver's cab 4 and receives various operation inputs from the operator, outputting signals corresponding to the operation inputs to the controller 10. The input device D2 includes a touch panel mounted on the display of the display device D1, which includes a display device 42 that displays various information images, and knob switches provided at the ends of lever devices such as the slewing operation lever 44s. The input device D2 also includes button switches, levers, toggles, rotary dials, etc., installed around the display device 42 installed in the driver's cab 4. Signals corresponding to the operations performed on the input device D2 are input to the controller 10.

[0076] Communication device CD communicates with external devices through a predetermined network, including a mobile communication network with a base station as its endpoint, a satellite communication network, and the Internet network. Communication device CD includes, for example, a mobile communication module that supports mobile communication standards such as LTE (Long Term Evolution), 4G (4th Generation), and 5G (5th Generation), and a satellite communication module for connecting to a satellite communication network.

[0077] Figure 6 is a functional block diagram of the controller 10 shown in Figure 5. As shown in Figure 6, the controller 10 includes, for example, a turning stop control determination unit 101, an angular acceleration waveform generation unit 102, and a drive control unit 103. Each of these parts of the controller 10 represents a function of the controller 10 that is realized, for example, by loading a program stored in the auxiliary storage device 10A into the memory device 10C by the processing unit 10B and executing it. Note that each part of the controller 10 shown in Figure 6 may be realized by a single controller or by multiple different controllers.

[0078] The operation of each part of the controller 10 will be explained below with reference to Figure 7. Figure 7 is a flowchart showing an example of the operation of the controller 10 in slewing stop control. For example, when the amount of slewing operation of the slewing operation lever 44s by the operator of the crane 1 is input from the operation sensor 17, and the slewing angular velocity or slewing angular acceleration of the upper slewing body 3 is input from the slewing sensor S1, the controller 10 starts the processing flow shown in Figure 7.

[0079] The controller 10 first executes a process P01 to determine whether or not to perform slewing stop control. In this process P01, the slewing stop control determination unit 101 determines, for example, whether or not the conditions for slewing stop control are met while the upper slewing body 3 is slewing. Specifically, the slewing stop control determination unit 101 determines to perform slewing stop control (YES) if, for example, the operator of the crane 1 presses the emergency stop button included in the input device D2 while the upper slewing body 3 is slewing.

[0080] Furthermore, the slewing stop control determination unit 101 determines whether to execute slewing stop control (YES) if, for example, it detects that the operator's hand of the crane 1 suddenly leaves the slewing operation lever 44s of the operating device OD while the upper slewing body 3 is slewing. The slewing stop control determination unit 101 detects, for example, that the operator's hand of the crane 1 suddenly leaves the slewing operation lever 44s based on the amount of operation of the slewing operation lever 44s input from the operating sensor 17.

[0081] On the other hand, the slewing stop control determination unit 101 determines not to perform slewing stop control (NO) if, for example, the emergency stop button is not pressed and the operator's hands of the crane 1 are not away from the slewing control lever 44s of the control device OD. In this case, the controller 10 terminates the processing flow shown in Figure 7 and repeats processing P01 at a predetermined cycle.

[0082] Furthermore, as described above, when the slewing stop control determination unit 101 determines in process P01 that slewing stop control should be executed (YES), the controller 10 executes process P02 to acquire the swing angle and process P03 to acquire the slewing angular acceleration of the upper slewing body 3. In process P02, the angular acceleration waveform generation unit 102 acquires the swing angle of the suspended load attached to the boom hook 81 or jib hook 82 from the swing sensor S5, and in process P03, acquires the slewing angular velocity and slewing angular acceleration of the upper slewing body 3 from the slewing sensor S1.

[0083] Next, the controller 10 performs a process P04 to generate an angular acceleration waveform that automatically stops the upper slewing body 3, and a process P05 to stop the rotation of the upper slewing body 3 based on that angular acceleration waveform. In process P04, the angular acceleration waveform generation unit 102 generates an angular acceleration waveform of the rotation angle of the upper slewing body 3 that suppresses the swing of hooks such as the boom hook 81 or jib hook 82, and outputs it to the drive control unit 103. In process P05, the drive control unit 103 controls the rotational angular acceleration of the upper slewing body 3 based on the angular acceleration waveform input from the angular acceleration waveform generation unit 102, thereby stopping the rotation of the upper slewing body 3.

[0084] Specifically, the drive control unit 103 outputs a control command to the proportional control valve 15 based on the angular acceleration waveform input from the angular acceleration waveform generation unit 102. Based on the control command input from the drive control unit 103, the proportional control valve 15 controls the pilot pressure of the hydraulic fluid supplied from the pilot pump 14 to the control valve 133 of the control valve unit 13. As a result, the flow rate and direction of the hydraulic fluid supplied from the main pump 12 to the swing motor 3A via the control valve 133 are controlled.

[0085] Then, the slewing motor 3A controls the slewing angular velocity of the upper slewing body 3 so that the angular acceleration in the slewing direction at the sheave at the tip of the attachment AT changes according to the angular acceleration waveform generated by the angular acceleration waveform generation unit 102. As a result, the slewing of the upper slewing body 3 automatically stops while the swing of the suspended load attached to the hook suspended from the sheave at the tip of the attachment AT is suppressed. After that, the controller 10 terminates the processing flow shown in Figure 7.

[0086] Figures 8 to 10 show examples of angular acceleration waveforms AW1, AW2, and AW3 generated by the angular acceleration waveform generation unit 102. The angular acceleration waveform generation unit 102 generates angular acceleration waveforms AW1, AW2, and AW3 in the rotational direction of the upper slewing body 3 at the sheave at the tip of the attachment AT, for example, as control target values ​​for slewing stop control. A wire rope for suspending the boom hook 81, such as the front drum wire rope 83 that suspends the boom hook 81, is hung on the sheave at the tip of the attachment AT. A load is also hung on the hook suspended from the sheave via the wire rope.

[0087] In Figures 8 to 10, the upper graph shows the angular acceleration d, which is the second time derivative of the rotation angle θ [rad] of the upper rotating body 3, with the vertical axis being the time derivative. 2 θ / dt 2 [rad / s 2 The graph shows the angular acceleration waveforms AW1, AW2, and AW3 of the rotation of the upper rotating body 3, with the horizontal axis representing time T [s]. In each figure, the lower graphs are phase planes PP1, PP2, and PP3, which show the transition of phase points corresponding to the swing angle φ of the suspended load in the rotation direction of the upper rotating body 3.

[0088] The phase planes PP1, PP2, and PP3 in each figure correspond to the angular acceleration waveforms AW1, AW2, and AW3 in each figure, respectively. In each phase plane PP1, PP2, and PP3, the horizontal axis represents the angular velocity dφ / dt [rad / s], which is the time derivative of the swing angle φ of the suspended load, and the vertical axis represents the angular acceleration dφ / dt, which is the second time derivative of the swing angle φ of the suspended load. 2 φ / dt 2 [rad / s 2This value is obtained by dividing ] by the angular frequency ω [rad / s] of the swing of the suspended load. The angular frequency ω of the swing of the suspended load is expressed as ω = 2π / Tc, where Tc is the period of the swing of the suspended load.

[0089] The angular acceleration waveforms AW1, AW2, and AW3 share the common feature of including a first period T1 in which the angular acceleration decreases from zero at a constant first rate of change j1, and a final period Tf in which, after a predetermined period has elapsed from the first period T1, the angular acceleration increases at a rate of change -j1 which is the opposite of the first rate of change j1, until the angular acceleration becomes zero.

[0090] Furthermore, the angular acceleration waveform AW1 shown in Figure 8 includes a second period T2 in which it increases at a constant second rate of change j2, following the first period T1, and a third period T3 in which it decreases at a third rate of change j3 equal to the first rate of change j1, following the second period T2. In addition, the angular acceleration waveform AW1 includes a fourth period T4 in which it increases at a fourth rate of change j4 with the opposite sign of the third rate of change j3, following the third period T3, a fifth period T5 in which it decreases at a fifth rate of change j5 with the opposite sign of the second rate of change j2, following the fourth period T4, and a final period Tf following the fifth period T5.

[0091] The magnitudes of the rates of change of the first rate of change j1, the second rate of change j2, etc., of the angular acceleration in the angular acceleration waveform AW1, and the length of each period T1-Tf, are determined based on the phase point of the swing angle φ of the suspended load in the phase plane PP1. Specifically, when the angular velocity and angular acceleration of the swing angle φ of the suspended load are zero during the rotation of the upper slewing body 3, the phase point of the swing angle φ of the suspended load is located at the origin of the phase plane PP1.

[0092] In this state, the rotation stop control is initiated, and the rotational angular acceleration of the upper rotating body 3 is controlled to reduce the rotational angular acceleration of the upper rotating body 3 at the sheave at the tip of the attachment AT by a first rate of change j1, as in the first period T1 of the angular acceleration waveform AW1. As a result, the angular velocity and angular acceleration of the swing angle φ of the hook and suspended load increase, and the phase point of the swing angle φ of the hook and suspended load in the phase plane PP1 moves upward along the arc A1 centered on the point "-j1 / g" on the horizontal axis. Hereinafter, "g" is the acceleration due to gravity.

[0093] Furthermore, by controlling the rotational angular acceleration of the upper slewing body 3, the rotational angular acceleration of the upper slewing body 3 at the tip of the attachment AT is increased by a second rate of change j2, as in the second period T2 of the angular acceleration waveform AW1. As a result, the angular acceleration of the swing angle φ of the suspended load decreases while the angular velocity changes from increasing to decreasing, causing the phase point of the swing angle φ of the suspended load in the phase plane PP1 to move downward along the arc A2 centered at the point "-j2 / g" on the horizontal axis.

[0094] Furthermore, by controlling the rotational angular acceleration of the upper slewing body 3, the rotational angular acceleration of the upper slewing body 3 at the tip of the attachment AT is reduced by a third rate of change j3 equal to the first rate of change j1, as in the third period T3 of the angular acceleration waveform AW1. As a result, the angular velocity of the swing angle φ of the hook and suspended load decreases and the angular acceleration increases, causing the phase point of the swing angle φ of the hook and suspended load in the phase plane PP1 to move upward to the origin along the arc A3 centered at the point "-j1 / g" on the horizontal axis.

[0095] Furthermore, by controlling the rotational angular acceleration of the upper slewing body 3, the rotational angular acceleration of the upper slewing body 3 at the tip of the attachment AT is increased by a fourth rate of change j4, which is the opposite of the third rate of change j3, as in the fourth period T4 of the angular acceleration waveform AW1. As a result, the angular velocity and angular acceleration of the swing angle φ of the hook and suspended load decrease, and the phase point of the swing angle φ of the hook and suspended load in the phase plane PP1 moves downward along the arc A4 centered on the point "-j1 / g" and the point "j1 / g" with the opposite sign on the horizontal axis.

[0096] Furthermore, by controlling the rotational angular acceleration of the upper slewing body 3, the rotational angular acceleration of the upper slewing body 3 at the tip of the attachment AT is reduced by a fifth rate of change j5, which is the opposite of the second rate of change j2, as in the fifth period T5 of the angular acceleration waveform AW1. As a result, the angular acceleration of the swing angle φ of the hook and the suspended load increases while the angular velocity changes from increasing to decreasing, causing the phase point of the swing angle φ of the hook and the suspended load in the phase plane PP1 to move upward along the arc A5 centered on the horizontal axis point "-j2 / g" and the opposite point "j2 / g".

[0097] Finally, the rotational angular acceleration of the upper slewing body 3 is controlled to increase the rotational angular acceleration of the upper slewing body 3 at the tip of the attachment AT by a rate of change -j1 that is the opposite of the first rate of change j1, as in the final period Tf of the angular acceleration waveform AW1. As a result, the angular velocity of the swing angle φ of the hook and suspended load increases while the angular acceleration decreases, causing the phase point of the swing angle φ of the hook and suspended load in the phase plane PP1 to move downward along the arc A6 centered on the horizontal axis point "j1 / g" and stop at the origin. Consequently, when the rotation of the upper slewing body 3 stops, the angular velocity and angular acceleration of the swing angle φ of the hook and suspended load become zero, and the swing of the hook and suspended load is suppressed.

[0098] In the angular acceleration waveform AW1 shown in Figure 8, the time from the start of the first period T1 to the end of the final period Tf can be expressed as {(2α+β) / π}Tc, using the central angles α of arc A1 and β of arc A2 in the phase plane PP1, and the swing period Tc of the suspended load. Therefore, by adjusting the central angles α of arc A1 and β of arc A2 in the phase plane PP1 to make (2α+β) / π less than or equal to 1, the time from the start of the slewing stop control until the slewing of the upper slewing body 3 and the swing of the hook and suspended load stop can be shortened to less than the swing period Tc. As a result, the swing of the hook and suspended load can be stopped in one period or less.

[0099] Furthermore, the angular acceleration waveform AW2 shown in Figure 9 includes a second period T2 in which the rate of change j2 becomes zero, following the first period T1, and a third period T3 in which it decreases at a third rate of change j3 equal to the first rate of change j1, following the second period T2. In addition, the angular acceleration waveform AW2 includes a fourth period T4 in which it increases at a fourth rate of change j4 which is the opposite of the third rate of change j3, following the third period T3, a fifth period T5 in which the rate of change j5 becomes zero, following the fourth period T4, and a final period Tf following the fifth period T5.

[0100] The magnitudes of the first and second rates of change j1 and j2 of the angular acceleration in the angular acceleration waveform AW2, and the length of each period, are determined based on the phase point of the swing angle φ of the hook and suspended load in the phase plane PP2. Specifically, when the angular velocity and angular acceleration of the swing angle φ of the hook and suspended load are zero during the rotation of the upper slewing body 3, the phase point of the swing angle φ of the hook and suspended load is located at the origin of the phase plane PP2.

[0101] In this state, the slewing stop control is initiated, and the slewing angular acceleration of the upper slewing body 3 is controlled to reduce the angular acceleration of the upper slewing body 3 in the slewing direction at the sheave at the tip of the attachment AT by a first rate of change j1, as in the first period T1 of the angular acceleration waveform AW2. As a result, the angular velocity and angular acceleration of the swing angle φ of the hook and suspended load increase, and the phase point of the swing angle φ of the hook and suspended load in the phase plane PP2 moves upward along the arc A1 centered at the point "-j1 / g" on the horizontal axis.

[0102] Furthermore, by controlling the rotational angular acceleration of the upper slewing body 3, the rate of change j2 of the rotational angular acceleration of the upper slewing body 3 at the tip of the attachment AT is kept at zero, as in the second period T2 of the angular acceleration waveform AW2. As a result, the angular acceleration of the swing angle φ of the hook and suspended load decreases, and the angular velocity changes from increasing to decreasing, causing the phase point of the swing angle φ of the hook and suspended load in the phase plane PP2 to move downward along the arc A2 centered at the origin.

[0103] Furthermore, by controlling the rotational angular acceleration of the upper slewing body 3, the rotational angular acceleration of the upper slewing body 3 at the tip of the attachment AT is reduced by a third rate of change j3 equal to the first rate of change j1, as in the third period T3 of the angular acceleration waveform AW2. As a result, the angular velocity of the swing angle φ of the hook and suspended load decreases and the angular acceleration increases, causing the phase point of the swing angle φ of the hook and suspended load in the phase plane PP2 to move upward to the origin along the arc A3 centered at the point "-j1 / g" on the horizontal axis.

[0104] Furthermore, by controlling the rotational angular acceleration of the upper slewing body 3, the rotational angular acceleration of the upper slewing body 3 at the tip of the attachment AT is increased by a fourth rate of change j4, which is the opposite of the third rate of change j3, as in the fourth period T4 of the angular acceleration waveform AW2. As a result, the angular velocity and angular acceleration of the swing angle φ of the hook and suspended load decrease, and the phase point of the swing angle φ of the hook and suspended load in the phase plane PP2 moves downward along the arc A4 centered on the point "-j1 / g" on the horizontal axis and the point "j1 / g" with the opposite sign.

[0105] Furthermore, the rotational angular acceleration of the upper slewing body 3 is controlled to maintain the rate of change j5 of the rotational angular acceleration of the upper slewing body 3 at the tip of the attachment AT at zero, as in the fifth period T5 of the angular acceleration waveform AW2. As a result, the angular acceleration of the swing angle φ of the hook and suspended load increases while the angular velocity changes from increasing to decreasing, causing the phase point of the swing angle φ of the hook and suspended load in the phase plane PP2 to move upward along the arc A5 centered at the origin.

[0106] Finally, the rotational angular acceleration of the upper slewing body 3 is controlled to increase the rotational angular acceleration of the upper slewing body 3 at the tip of the attachment AT by a rate of change -j1 that is the opposite of the first rate of change j1, as in the final period Tf of the angular acceleration waveform AW2. As a result, the angular velocity of the swing angle φ of the hook and suspended load increases while the angular acceleration decreases, causing the phase point of the swing angle φ of the hook and suspended load in the phase plane PP2 to move downward along the arc A6 centered on the horizontal axis point "j1 / g" and stop at the origin. Consequently, when the rotation of the upper slewing body 3 stops, the angular velocity and angular acceleration of the swing angle φ of the hook and suspended load become zero, and the swing of the hook and suspended load is suppressed.

[0107] In the angular acceleration waveform AW2 shown in Figure 9, the time from the start of the first period T1 to the end of the final period Tf can be expressed as {(2α+β) / π}Tc, using the central angles α of arc A1 and β of arc A2 in the phase plane PP1, and the period Tc of the swing of the hook and suspended load. Therefore, by adjusting the central angles α of arc A1 and β of arc A2 in the phase plane PP1 to make (2α+β) / π less than or equal to 1, the time from the start of the slewing stop control until the slewing of the upper slewing body 3 and the swing of the hook and suspended load stop can be shortened to less than the swing period Tc. As a result, the swing of the hook and suspended load can be stopped in one period or less.

[0108] Furthermore, the angular acceleration waveform AW3 shown in Figure 10 includes a second period T2 in which the rate of change j2 becomes zero, following the first period T1, and a final period Tf that follows the second period T2.

[0109] The magnitude of the first rate of change j1 of angular acceleration in the angular acceleration waveform AW3, and the length of each period, are determined based on the phase point of the swing angle φ of the hook and suspended load in the phase plane PP3. Specifically, when the angular velocity and angular acceleration of the swing angle φ of the hook and suspended load are zero during the rotation of the upper slewing body 3, the phase point of the swing angle φ of the hook and suspended load is located at the origin of the phase plane PP3.

[0110] In this state, the rotation stop control is initiated, and the rotational angular acceleration of the upper rotating body 3 is controlled to reduce the rotational angular acceleration of the upper rotating body 3 at the sheave at the tip of the attachment AT by a first rate of change j1, as in the first period T1 of the angular acceleration waveform AW3. As a result, the angular velocity and angular acceleration of the swing angle φ of the hook and suspended load increase, and the phase point of the swing angle φ of the hook and suspended load in the phase plane PP3 moves upward along the arc A1 centered at the point "-j1 / g" on the horizontal axis.

[0111] Furthermore, by controlling the rotational angular acceleration of the upper slewing body 3, the rate of change j2 of the rotational angular acceleration of the upper slewing body 3 at the tip of the attachment AT is kept at zero, as in the second period T2 of the angular acceleration waveform AW3. As a result, the angular acceleration of the swing angle φ of the hook and suspended load decreases while the angular velocity changes from increasing to decreasing, causing the phase point of the swing angle φ of the hook and suspended load in the phase plane PP3 to move in a circular motion along the arc A2 centered at the origin.

[0112] Finally, the rotational angular acceleration of the upper slewing body 3 is controlled to increase the rotational angular acceleration of the upper slewing body 3 at the tip of the attachment AT by a first rate of change j1 and a rate of change -j1 with the opposite sign, as shown in the final period Tf of the angular acceleration waveform AW3. As a result, the angular velocity of the swing angle φ of the hook and suspended load increases while the angular acceleration decreases, causing the phase point of the swing angle φ of the hook and suspended load in the phase plane PP3 to move downward along the arc A3 centered on the point "-j1 / g" on the horizontal axis and the point "j1 / g" with the opposite sign, and to stop at the origin. Consequently, when the rotation of the upper slewing body 3 stops, the angular velocity and angular acceleration of the swing angle φ of the hook and suspended load become zero, and the swing of the hook and suspended load is suppressed.

[0113] In the angular acceleration waveform AW2 shown in Figure 10, the time from the start of the first period T1 to the end of the final period Tf can be expressed as {(α+β) / π}Tc, using the central angles α of arc A1 and β of arc A2 in the phase plane PP1, and the period Tc of the swing of the hook and suspended load. Therefore, by adjusting the central angles α of arc A1 and β of arc A2 in the phase plane PP1 to bring (α+β) / π closer to 1, the time from the start of the rotation stop control until the rotation of the upper rotating body 3 stops and the swing of the hook and suspended load stops can be further shortened.

[0114] As shown in the examples from Figures 8 to 10, the controller 10 calculates the time and rate of change of each period, such as the first period T1 and the second period T2 of the angular acceleration waveforms AW1, AW2, and AW3, and the rate of change, such as the first rate of change j1 and the second rate of change j2, using phase planes PP1, PP2, and PP3. In each of the phase planes PP1, PP2, and PP3, the controller 10 calculates the time and rate of change of each period such that the phase point of the suspended load and hook starts from the origin and returns to the origin via multiple circular arcs based on the rate of change of each period of the angular acceleration waveforms AW1, AW2, and AW3. As described above, the phase planes PP1, PP2, and PP3 have the time derivative value dφ / dt of the swing angle φ of the suspended load and hook on the horizontal axis and the second time derivative value d 2 φ / dt 2 The vertical axis represents the value obtained by dividing this value by the angular frequency ω of the swing of the suspended load and hook.

[0115] Figure 11 shows a comparison of the angular acceleration waveforms AW1, AW2, and AW3 from Figures 8 to 10. The upper graph G1 in Figure 11 shows the relationship between the time Ts until the swing of the hook and suspended load stops and the magnitude of the first rate of change j1 of the angular acceleration waveform AW3. The lower graph G2 in Figure 11 shows the relationship between the maximum value φL of the swing angle φ of the hook and suspended load at the time of rotation cessation and the magnitude of the first rate of change j1 of the angular acceleration waveform AW3.

[0116] As shown in graph G1 at the top of Figure 11, increasing the magnitude of the first rate of change j1 reduces the time Ts until the swing of the hook and suspended load stops. Furthermore, in the angular acceleration waveform AW1, increasing the magnitude of the first rate of change j1 allows the swing of the suspended load to be stopped in a shorter time than the swing period Tc of the hook and suspended load.

[0117] On the other hand, as shown in graph G2 at the bottom of Figure 11, in angular acceleration waveform AW1, increasing the magnitude of the first rate of change j1 tends to increase the maximum value φL of the swing angle of the hook and suspended load. Also, in angular acceleration waveform AW3, increasing the magnitude of the first rate of change j1 eventually makes the maximum value φL of the swing angle of the suspended load smaller than that of angular acceleration waveform AW1. Furthermore, angular acceleration waveform AW2 has a greater effect on reducing the maximum value φL of the swing angle of the suspended load compared to the other angular acceleration waveforms AW1 and AW2.

[0118] Figure 12 shows a comparison between the angular acceleration waveform AW11 of Example 1, which corresponds to the angular acceleration waveform AW1 in Figure 8, and the angular acceleration waveform AWc1 of Comparative Example 1, where the rate of change of angular acceleration is zero from beginning to end. The upper graph G3 in Figure 12 shows the angular acceleration waveforms AW11 and AWc1 of Example 1 and Comparative Example 1, with the vertical axis representing angular acceleration, and the angular velocity waveforms VW11 and VWc1 of Example 1 and Comparative Example 1, with the vertical axis representing angular velocity. The lower graph G4 in Figure 12 shows the temporal change in the swing angle φ of the suspended load, which corresponds to the angular acceleration waveforms AW11 and AWc1 of Example 1 and Comparative Example 1, with the vertical axis representing the swing angle φ of the suspended load and the horizontal axis representing time T.

[0119] In the upper graph G3 of Figure 12, when the angular acceleration of the tip of the attachment AT is controlled according to the angular acceleration waveform AWc1 of Comparative Example 1, shown by the thin dashed line, the angular velocity waveform VWc1 of the tip of the attachment AT decreases at a constant rate of change, shown by the thin dashed line, until it becomes zero. On the other hand, in the upper graph G3 of Figure 12, when the angular acceleration of the tip of the attachment AT is controlled according to the angular acceleration waveform AW11 of Example 1, shown by the thick solid line, the angular velocity waveform VW11 of the tip of the attachment AT decreases while the rate of change repeatedly increases and decreases, as shown by the thick dotted line.

[0120] As a result, in graph G4 at the bottom of Figure 12, the swing angle φ of the suspended load corresponding to the angular acceleration waveform AW11 in Example 1, shown by the thick solid line, becomes zero in a shorter time than the swing angle φ of the suspended load corresponding to the angular acceleration waveform AWc1 in Comparative Example 1, shown by the thin dashed line. On the other hand, the maximum value of the swing angle φ of the suspended load corresponding to the angular acceleration waveform AW11 in Example 1, shown by the thick solid line, is slightly higher than the maximum value of the swing angle φ of the suspended load corresponding to the angular acceleration waveform AWc1 in Comparative Example 1, shown by the thin dashed line.

[0121] Figure 13 shows a comparison between the angular acceleration waveform AW12 of Example 2, which corresponds to the angular acceleration waveform AW1 in Figure 8, and the angular acceleration waveform AWc2 of Comparative Example 2, where the rate of change of angular acceleration is zero from beginning to end. The upper graph G5 in Figure 13 shows the angular acceleration waveforms AW12 and AWc2 of Example 2 and Comparative Example 2, with angular acceleration on the vertical axis, and the angular velocity waveforms VW12 and VWc2 of Example 2 and Comparative Example 2, with angular velocity on the vertical axis. The lower graph G6 in Figure 13 shows the temporal change in the swing angle φ of the suspended load, corresponding to the angular acceleration waveforms AW12 and AWc2 of Example 2 and Comparative Example 2, with the swing angle φ of the suspended load on the vertical axis and time T on the horizontal axis.

[0122] In the upper graph G5 of Figure 13, when the angular acceleration of the tip of the attachment AT is controlled according to the angular acceleration waveform AWc2 of Comparative Example 2, shown by the thin dashed line, the angular velocity waveform VWc2 of the tip of the attachment AT decreases at a constant rate of change, shown by the thin dashed line, until it becomes zero. On the other hand, in the upper graph G5 of Figure 13, when the angular acceleration of the tip of the attachment AT is controlled according to the angular acceleration waveform AW12 of Example 2, shown by the thick solid line, the angular velocity waveform VW12 of the tip of the attachment AT decreases while the rate of change repeatedly increases and decreases, as shown by the thick dotted line.

[0123] As a result, in graph G6 at the bottom of Figure 13, the maximum value of the swing angle φ of the suspended load corresponding to the angular acceleration waveform AW12 in Example 2, shown by the thick solid line, is smaller than the maximum value of the swing angle φ of the suspended load corresponding to the angular acceleration waveform AWc2 in Comparative Example 2, shown by the thin dashed line. On the other hand, the time it takes for the swing angle φ of the suspended load corresponding to the angular acceleration waveform AW12 in Example 2, shown by the thick solid line, to become zero is approximately the same as the time it takes for the swing angle φ of the suspended load corresponding to the angular acceleration waveform AWc2 in Comparative Example 2, shown by the thin dashed line, to become zero.

[0124] Thus, by adjusting the first rate of change j1 and the second rate of change j2 of the angular acceleration waveforms AW11 and AW12 in Examples 1 and 2, it is possible to reduce the swing angle φ of the suspended load when controlling the stopping of the upper slewing body 3, or to shorten the time until the swing of the suspended load stops.

[0125] Figure 14 shows an example of the swing of the suspended load HL during slewing stop control. Figure 14 is a plan view of the boom hook 81 suspended via a wire rope from a sheave provided at the tip of the attachment AT, and the suspended load HL attached to the boom hook 81. Figure 14 shows the slewing direction RD of the upper slewing body 3 and the luffing direction UD of the attachment AT.

[0126] As shown in the initial state F0 in Figure 14, while the upper slewing body 3 is rotating, the controller 10 starts slewing stop control when the swing angle φ, angular velocity, and angular acceleration of the suspended load HL in the slewing direction RD are zero. Then, the controller 10 controls the rotation of the upper slewing body 3 so that the angular acceleration of the tip of the attachment AT follows the angular acceleration waveforms AW1, AW2, and AW3 that suppress the swing of the suspended load HL.

[0127] As shown in Figure 14, in the first stage F1, the swing angle φ of the suspended load HL increases, and in the second stage F2, the swing angle φ of the suspended load HL reaches its maximum. Subsequently, the swing angle φ of the suspended load HL decreases, and in the third stage, the swing of the suspended load HL stops simultaneously with the stopping of the rotation of the upper slewing body 3, or the swing of the suspended load HL is suppressed to a degree greater than before.

[0128] The operation of the crane 1 in this embodiment will be described below.

[0129] As described above, the crane 1 of this embodiment includes a rotatable upper slewing body 3, an attachment AT that is rotatable on the upper slewing body 3, and a hook such as a boom hook 81 that is suspended via the attachment AT so as to be able to move up and down. The crane 1 also includes a controller 10 that controls the rotational angular acceleration of the upper slewing body 3 based on angular acceleration waveforms AW1, AW2, and AW3 that suppress the swing of the hook, in rotation stop control that automatically stops the rotation of the upper slewing body 3. The angular acceleration waveforms AW1, AW2, and AW3 include a first period T1 in which the angular acceleration decreases from zero at a constant first rate of change j1, and a final period Tf in which, after a predetermined period has elapsed from the first period T1, the angular acceleration increases at a rate of change -j1 that is the opposite of the first rate of change j1, and the angular acceleration becomes zero.

[0130] With this configuration, according to the crane 1 of this embodiment, when the controller 10 controls the stopping of the rotation of the upper slewing body 3, the rotational angular velocity of the upper slewing body 3 can be controlled based on angular acceleration waveforms AW1, AW2, and AW3 that suppress the swing of the hook. Therefore, according to this embodiment, a crane 1 capable of suppressing the swing of the suspended load when rotation is stopped can be provided.

[0131] Furthermore, in the crane 1 of this embodiment, the angular acceleration waveform AW1 includes a second period T2 in which it increases at a constant second rate of change j2, following the first period T1, and a third period T3 in which it decreases at a third rate of change j3 equal to the first rate of change j1, following the second period T2. The angular acceleration waveform AW1 also includes a fourth period T4 in which it increases at a fourth rate of change j4 which is the opposite of the third rate of change j3, following the third period T3, a fifth period T5 in which it decreases at a fifth rate of change j5 which is the opposite of the second rate of change j2, following the fourth period T4, and a final period Tf which is following the fifth period T5.

[0132] With this configuration, when the slewing stop control of the upper slewing body 3 is performed, the crane 1 can reduce the time Ts until the swing of the hook such as the boom hook 81 or the suspended load hung on the hook stops, as compared with the case of using other angular acceleration waveforms such as the angular acceleration waveforms AW2 and AW3.

[0133] Further, in the crane 1 of the present embodiment, the angular acceleration waveform AW2 includes a second period T2 in which the change rate j2 becomes zero continuously in the first period T1, and a third period T3 in which the change rate decreases at a third change rate j3 equal to the first change rate j1 continuously to the second period T2. Further, the angular acceleration waveform AW2 includes a fourth period T4 in which the change rate increases at a fourth change rate j4 having the opposite sign to the third change rate j3 continuously to the third period T3, a fifth period T5 in which j5 becomes zero continuously to the fourth period T4, and a final period Tf continuous to the fifth period T5.

[0134] With this configuration, when the slewing stop control of the upper slewing body 3 is performed, the crane 1 can reduce the maximum value φL of the swing angle of the hook such as the boom hook 81 or the suspended load hung on the hook, as compared with the case of using other angular acceleration waveforms such as the angular acceleration waveforms AW1 and AW3.

[0135] Further, in the crane 1 of the present embodiment, the angular acceleration waveform AW3 includes a second period T2 in which the change rate j2 becomes zero continuously in the first period T1, and a final period Tf continuous to the second period T2.

[0136] With this configuration, when the slewing stop control of the upper slewing body 3 is performed, the crane 1 can achieve a reduction in the stop time Ts and a reduction in the maximum value φL of the swing angle in the swing of the suspended load with a simpler waveform, as compared with the case of using other angular acceleration waveforms such as the angular acceleration waveforms AW1 and AW2.

[0137] Further, in the crane 1 of the present embodiment, the controller 10 uses the time differential value dφ / dt of the swing angle φ of the hook as the horizontal axis and the second time differential value d 2 φ / dt 2Phase planes PP1, PP2, and PP3 are used, with the vertical axis representing the value obtained by dividing by the angular frequency ω of the hook's deflection. Controller 10 calculates the time and rate of change for each period in the phase planes PP1, PP2, and PP3 such that the phase point of the hook starts from the origin and returns to the origin via multiple circular arcs based on the rate of change for each period of the angular acceleration waveforms AW1, AW2, and AW3.

[0138] With this configuration, when controlling the rotational stopping of the upper slewing body 3, the crane 1 can control the rotational angular velocity of the upper slewing body 3 based on angular acceleration waveforms AW1, AW2, and AW3, thereby suppressing the swing of the hook or the suspended load attached to the hook.

[0139] Preferred embodiments of the present disclosure have been described above. However, the inventions of the present disclosure are not limited to the embodiments described above. Various modifications, substitutions, etc., can be applied to the embodiments described above without departing from the scope of the inventions of the present disclosure. Furthermore, each of the features described with reference to the embodiments described above may be combined as appropriate, as long as they do not contradict each other technically. [Explanation of Symbols]

[0140] 1 Crane 3. Upper rotating body 10 Controllers 81 Boom Hook (Hook) 82 Jib Hook (Hook) A1 Arc A2 arc A3 Arc A4 Arc A5 Arc A6 Arc AT attachment AW1 Angular acceleration waveform AW11 Angular acceleration waveform AW12 Angular acceleration waveform AW2 angular acceleration waveform AW3 Angular acceleration waveform j1 First rate of change j2 Second rate of change j3 Third rate of change j4 4th rate of change j5 Fifth rate of change PP1 phase plane PP2 phase plane PP3 phase plane T1 Period 1 T2 Second Period T3 Third Period T4 Period 4 T5 Period 5 Tf final period φ Deflection angle

Claims

1. A rotatable upper rotating body, An attachment is provided on the upper rotating body so as to be able to be raised and lowered, A hook suspended via the aforementioned attachment so as to be able to move up and down, The rotation stop control for automatically stopping the rotation of the upper rotating body includes a controller that controls the rotational angular acceleration of the upper rotating body based on an angular acceleration waveform that suppresses the swing of the hook, The angular acceleration waveform is, The first period is when the angular acceleration decreases from zero at a constant first rate of change, The period includes the first period followed by a final period after a predetermined period has elapsed, during which the angular acceleration increases at a rate of change opposite to the first rate of change, and becomes zero. crane.

2. The angular acceleration waveform is, A second period in which the first period is continuously increased at a constant second rate of change, A third period in which the second period is followed by a third period in which the rate of change decreases at a rate equal to the first rate of change, A fourth period is formed in which the third period is followed by a fourth period in which the rate of change is the opposite of the third rate of change, A fifth period in which the rate of change decreases continuously with a fifth rate of change that is the opposite of the second rate of change in sign, Including the final period that is continuous with the fifth period, The crane according to claim 1.

3. The angular acceleration waveform is, A second period in which the rate of change is zero for a continuous period in the first period, A third period in which the second period is followed by a third period in which the rate of change decreases at a rate equal to the first rate of change, A fourth period is formed in which the third period is followed by a fourth period in which the rate of change is the opposite of the third rate of change, A fifth period in which the rate of change becomes zero for the fourth period, Including the final period that is continuous with the fifth period, The crane according to claim 1.

4. The angular acceleration waveform is, A second period in which the rate of change is zero for a continuous period in the first period, Including the final period which is continuous with the second period, The crane according to claim 1.

5. The controller calculates the time and rate of change for each period in a phase plane where the time derivative of the hook's deflection angle is on the horizontal axis and the value obtained by dividing the second time derivative of the deflection angle by the angular frequency of the hook's deflection is on the vertical axis, such that the phase point of the hook starts from the origin and returns to the origin via a plurality of circular arcs based on the rate of change for each period of the angular acceleration waveform. The crane according to any one of claims 1 to 4.

Images