Method for controlling the movement of a crane hook

Abstract

To provide a hook movement control method of a crane capable of excellently maintaining both of operating speed and controllability in the horizontal movement of a hook.SOLUTION: In feedback control of horizontal movement of a hook 16 of a mobile crane 1, an initial speed of rotational speed of a winch 13 at the time of starting a horizontal movement mode is set (ST7) based on a length of a boom 11 and the winding number of a rope so as to prevent reduction in operating speed and reduction in controllability due to occurrence of hunting immediately after the start of controlling. When an absolute value of a deviation between a current position and a lifting target value of the hook 16 successively detected is larger than a preset value (ST9-2, 10-2), the rotational speed of the winch 13 is reduced or increased from the initial speed as the absolute value of the deviation is larger (ST9-3, 10-3) so as to improve the controllability of the feedback control.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present invention relates to a method for controlling the movement of a crane hook, which performs horizontal movement, in which the hook moves horizontally with the ground, and translation movement, in which the hook moves parallel to the boom, simply by inputting an operation to extend, retract, or raise the boom. [Background technology]

[0002] In crane work, horizontal movement, which moves the hook horizontally to the ground, and translation movement, which moves the hook parallel to the boom, may be performed. Proposals have been made to improve the operability when moving a suspended load by such horizontal and translation movements. For example, in Patent Document 1 (JP Patent Publication No. 7-215680), a target lifting height value of the hook is calculated from the current lifting height value of the hook based on a control characteristic that changes the lifting height correction amount of the hook at a predetermined rate in response to changes in the elevation / depression angle (roofing angle) of the boom, and the rotation speed of the winch drum is changed based on this target lifting height value to move the hook horizontally. In the horizontal movement control method described in Patent Document 2 (JP Patent Publication No. 63-60897), the elevation / depression drive mechanism (roofing mechanism) is controlled according to the length of the boom and the number of ropes hung between the boom and the hook. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 7-215680 [Patent Document 2] Japanese Patent Application Publication No. 63-60897 Summary of the Invention [Problem to be solved by the invention]

[0004] Here, hunting and other issues are most likely to occur in control operations such as horizontal movement immediately after control begins. For example, when the crane boom is long or there are many ropes attached, the rope winding and unwinding operation may not be able to keep up with the boom hoisting operation after horizontal movement begins, making it impossible to move the hook with the load suspended horizontally. For this reason, in control operations for horizontal movement, the boom extension and hoisting speeds are fixed from the start at speeds slower than those used during normal crane operation, ensuring controllability at the expense of operating speed.

[0005] In addition, after the horizontal movement control operation has begun, if the rotation speed of the winch drum for winding and unwinding the rope is too fast, the error between the target lifting height value and the actual lifting height value of the hook will become large, which may result in hunting or other problems and reduced controllability.

[0006] Furthermore, some multi-stage booms have different boom extension / retraction speeds. For example, in the case of a five-stage boom, the second and third booms may be configured to extend and retract sequentially, while the fourth and fifth booms may be configured to extend and retract simultaneously. In this case, the rope cannot be wound or unwound in accordance with the extension and retraction of the fourth and fifth booms, which may reduce controllability of the horizontal movement.

[0007] In addition, to improve the controllability of horizontal and parallel movement, calibration is required to accurately manage the rope winding / releasing length (winding amount) and lifting height. Conventionally, the rope length is calibrated when the number of wire layers in the winch drum is specified for calibration. In this case, counting the number of layers is difficult and there is a possibility of mistakes. As for the lifting height, errors accumulate in the drum rotation detection during use, which can cause errors in the lifting height calculated based on the detected drum rotation speed, so it is necessary to calibrate it periodically.

[0008] In view of the above, an object of the present invention is to propose a method for controlling movement of a crane hook that can maintain both the operating speed and controllability of the horizontal movement of the hook in a good condition. [Means for solving the problem]

[0009] In order to solve the above problems, the present invention provides a method for controlling movement of a hook of a crane, in which movement control of a hook suspended by a wire rope from the tip of a boom is performed by a controller mainly composed of a computer, comprising the steps of: A horizontal movement mode for controlling the horizontal movement of the hook based on an external input operation is set as a control mode, and a lifting height target value for the horizontal movement is set; In horizontal movement mode, feedback control is performed to reel in and reel out the wire rope in sync with the boom elevation and extension operations based on external input operations so that the current position of the hook maintains the lifting height target value. The feedback control in horizontal movement mode is characterized by calculating the initial speed of the winch that winds and pays out the wire rope based on the boom length at the start of control and the number of loops of wire rope that are input in advance, and then rotating the winch at that initial speed to start the winding and paying out of the wire rope.

[0010] In the method of the present invention, the rotation speed of the winch at the start of the horizontal movement mode is set based on the length of the boom and the number of wire ropes attached. When the boom is long and the number of wire ropes attached is large, it is possible to avoid problems such as the wire rope not being able to keep up with the boom's raising and lowering movements, causing hunting and other problems immediately after the start of horizontal movement control, resulting in reduced controllability.

[0011] In addition, in the method of the present invention, in the feedback control of the horizontal movement mode, when the absolute value of the deviation between the current hook position detected successively and the lifting height target value is greater than a preset value, the rotational speed of the winch is slowed down or accelerated from the initial speed as the absolute value of the deviation increases, thereby improving the controllability of the feedback control.

[0012] In this case, in order to avoid problems such as hunting caused by fluctuations in the rotational speed of the winch, it is desirable to use a moving average of the absolute values ​​of deviation over a predetermined number of times as the absolute value of the deviation.

[0013] Furthermore, in the feedback control of the horizontal movement mode, it is desirable to regulate the upper limit of the boom lowering operation speed to a lower value the longer the boom is, and to regulate the upper limit of the boom start-up operation speed to a value that is a certain percentage lower than a preset upper limit of the start-up operation speed.

[0014] Next, as a boom telescopic mechanism, there is a mechanism that telescopically extends and retracts each boom step in sequence up to a predetermined number of steps, and telescopically extends and retracts each boom step simultaneously when the number of steps is greater than the predetermined number. In this case, when the booms of the steps that telescopically extend and retract simultaneously telescopically extend, i.e., when the boom length is longer than a predetermined number, the telescopic speed is so fast that the winding and unwinding operation of the wire rope cannot keep up, and the controllability of the horizontal movement is reduced. To avoid this, in the feedback control of the horizontal movement mode, when the boom extension operation is performed sequentially for each step at a number of steps less than a predetermined number of steps, the upper limit of the extension operation speed is set to a preset upper limit of the extension operation speed, and when the boom extension operation is performed simultaneously for each step at a number of steps greater than the predetermined number of steps, the upper limit of the extension operation speed is restricted to a value lower than the upper limit of the extension operation speed by a certain percentage.

[0015] In the crane hook movement control method of the present invention, the controller is further configured to set the control mode to a parallel movement mode in which the hook is moved parallel to the boom based on an external input operation, and to set a target suspension length value for the parallel movement, and in the parallel movement mode, to perform feedback control in which the wire rope is wound and unwound in synchronization with the boom extension / retraction operation based on an external input operation, so that the current position of the hook, which is successively detected, maintains the target suspension length value.

[0016] Even in the feedback control of the parallel movement mode, when the boom extension operation is performed in a number of stages less than or equal to a predetermined number, it is desirable to set the upper limit of the extension operation speed to a preset upper limit of the extension operation speed, and when the boom extension operation is performed in a number of stages more than the predetermined number, to restrict the upper limit of the extension operation speed to a value that is a certain percentage lower than the upper limit of the extension operation speed.

[0017] Furthermore, in order to perform feedback control of horizontal and parallel movements with high accuracy, it is necessary to detect the wire rope length and lifting height with high accuracy. For this reason, in the present invention, prior to feedback control, the detection value of the unwinding / rewinding amount of the wire rope is calibrated while the wire rope is unwound from the winch. Also, when the boom is fully retracted at a preset angle and the hook overwinding detection sensor attached to the end of the boom is on, automatic lifting height calibration is performed to match the detection value indicating the current position of the hook with a preset value. [Brief description of the drawings]

[0018] [Figure 1] 1 is an explanatory diagram of a mobile crane to which the present invention is applied, an explanatory diagram showing an operating lever etc. inside the cabin, and an explanatory diagram showing the number of ropes hung. [Diagram 2] 1A and 1B are explanatory diagrams showing horizontal movement of a hook and translational movement of a hook, respectively. [Diagram 3] FIG. 2 is a schematic functional block diagram showing a control system and a mechanical system of the mobile crane. [Figure 4] 13 is a schematic flowchart showing a control operation in a horizontal movement mode of the hook. [Diagram 5] 13 is a schematic flowchart showing a control operation in a parallel movement mode of the hook. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0019] Hereinafter, an embodiment of a mobile crane to which the hook movement control method of the present invention is applied will be described with reference to the drawings. However, the present invention is not limited to the embodiment described below.

[0020] As shown in FIG. 1(A), the mobile crane 1 is equipped with a crawler-type lower running body 2 and an upper rotating body 4 on which a telescopic boom 3 is mounted, and can move (travel) by itself within a work site and perform crane work within the rated total load.

[0021] The lower traveling body 2 is equipped with crawlers 8 suspended on sprockets 6 that are rotated by a traveling motor (not shown) on the left and right sides of a track frame 5. The upper rotating body 4 is rotatably mounted on the track frame 5, and the telescopic boom 3 mounted on the upper rotating body 4 is a multi-stage boom 11 (five stages in this example) that is equipped with a boom hoisting cylinder 12, a winch 13, a hook block 15 suspended from the tip of the boom by a wire rope 14 that is wound out from the winch 13, etc.

[0022] The boom 11 is a boom in which the second and third stages are sequentially telescopic, and the fourth and fifth stages are simultaneous telescopic. The hook block 15 suspended by the wire rope 14 from the tip of the boom 11 can be switched to have six, four, two or one optional rope hooks, as shown in Figure 1(C).

[0023] A cabin 17 is mounted on the side of the boom 11 on the upper rotating body 4. As shown in Fig. 1(B), inside the cabin 17, a safety lock lever 21, a pair of left and right travel levers 22, 23, a left work implement operation lever 24, a right work implement operation lever 25, an accelerator pedal 26, a display operation panel 27, etc. are arranged.

[0024] Mobile crane 1 is capable of operating in operation modes including a horizontal movement mode in which hook 16 of hook block 15 is moved horizontally to the ground G while maintaining lifting height H, as shown in Fig. 2(A), and a parallel movement mode in which hook 16 is moved parallel to boom 11 while maintaining suspension length L, as shown in Fig. 2(B). When the operation mode of mobile crane 1 is set to the horizontal movement mode or parallel movement mode, the operator can move hook 16 horizontally or parallel by simply extending or retracting boom 11.

[0025] FIG. 3 is a functional block diagram of the main parts of the mobile crane 1. The control system of the mobile crane 1 includes a main controller 30 and a travel controller 31, which are mainly composed of a computer. The mechanical system of the mobile crane 1 includes a winch 13 (hoisting device), a boom extension device 32, a boom hoisting device 33, a slewing device 34, a traveling device 35, a hydraulic device 36, an engine 37, etc. Each mechanical part is configured, for example, as follows. The winch 13 winds and reels in the wire rope 14 using a two-speed hydraulic motor with a built-in brake. The boom extension device 32 includes three hydraulic double-acting cylinders for sequential extension and retraction, and a wire rope extension device for simultaneous extension and retraction. The boom hoisting device 33 includes a boom hoisting cylinder 12 consisting of one double-acting hydraulic cylinder. The slewing device 34 is of a fixed displacement piston type. The traveling device 35 includes a hydraulic two-speed motor, a continuously variable transmission, and a planetary gear reduction mechanism with a built-in automatic brake. The hydraulic system 36 is of a variable displacement piston type equipped with a hydraulic oil tank, and supplies hydraulic oil to each hydraulically driven part. The engine 37 which is the drive source of the hydraulic system 36 uses diesel as fuel.

[0026] Operation signals are input to the main controller 30 from the safety lock lever 21, the pair of left and right travel levers 22, 23, the left work implement operation lever 24, the right work implement operation lever 25, the accelerator pedal 26, etc. Furthermore, an input operation signal is supplied to the main controller 30 from a display operation panel 27. Various operation buttons are arranged on the display operation panel 27. The operation buttons include a mode selection button 27a for setting the operation mode to a horizontal movement mode or a parallel movement mode, a number of ropes input button 27b for setting and inputting the number of ropes to be hung, etc. Various information can be displayed on a display screen 27c of the display operation panel 27 under the control of the main controller 30.

[0027] Furthermore, detection signals from various detectors are input to the main controller 30. The detection signals include a lifting height detection signal from a lifting height detection unit 41, a hook suspension length detection signal from a hook suspension length detection unit 42, a hoisting angle detection signal from a boom angle meter 43 that detects the hoisting angle of the boom 11, a boom length detection signal from a boom length meter 44, a rotation angle detection signal from a potentiometer (rotation angle detection unit) 45 attached to the rotation device 34, a detection signal from a hook overwinding sensor 46 (overwinding alarm detector) attached to the tip of the boom, and a detection signal from a rotation speed sensor 47 that detects the rotation speed of the winch drum.

[0028] Here, the left work implement operation lever 24 is used, for example, when rotating the upper rotating body 4 and extending and retracting the boom 11. In a rotating operation, the lever 24 is pulled to the right when rotating to the right, and the lever 24 is pushed to the left when rotating to the left. In addition, in a boom extension operation, the lever 24 is pulled backward when retracting the boom, and the lever 24 is pushed forward when extending the boom. When the hand is released from the lever 24, the lever 24 returns to and stops in the initial neutral position, and the upper rotating body and boom length remain stationary and maintain their positions.

[0029] The other right work implement operation lever 25 is used, for example, when operating the winch and raising and lowering the boom. In winch operation, the lever 25 is pulled backward when hoisting, and pushed forward when lowering. In boom hoist operation, the lever 25 is pushed to the right when lowering the boom, and pulled to the left when raising the boom. When the lever 25 is released, it returns to and stops in its initial neutral position, and the hook block and boom angle remain in their stopped positions.

[0030] In this example, a radio-controlled machine 50 is also provided to enable remote control. For example, when a remote control mode switching signal is input using the mode selection button 27a on the display and operation panel 27, the main controller 30 switches to the remote control mode, and can accept operation input signals from the radio-controlled machine 50 via the transmitting and receiving device 60 to perform crane operations, etc. On the operation surface of the radio-controlled machine 50, a display unit 51, a mode selection button 52, a rotation operation switch 53, a boom extension / retraction switch 54, a boom hoisting operation switch 55, a winch operation switch 56, etc. are arranged.

[0031] The main controller 30 includes a control unit 71 mainly composed of a computer, a storage unit 72 in which a control program, various control conditions, setting values, etc. are stored, and the like. By executing the control program, the control unit 71 functions as an operation mode setting unit 73 that sets the operation mode of the telescopic boom 3 to a horizontal movement mode, a parallel movement mode, etc. based on an input operation, a target value setting unit 74 that sets a lifting height target value that is a target value for feedback control in the horizontal movement mode based on an operation input, and a hook suspension length target value that is a target value for feedback control in the parallel movement mode, and a feedback control unit 75 that performs feedback control so that the detected lifting height and suspension length become the target values, and the like.

[0032] (Horizontal movement mode) 4 is a schematic flow chart showing the operation of the mobile crane 1 in the horizontal movement mode. When the operator operates the mode selection button 27a on the display operation panel 27, the main controller 30 sets the operation mode to the horizontal movement mode (step ST1: hook horizontal mode ON). In addition, the main controller 30 sets the current lifting height detected by the lifting height detection unit 41 to a lifting height target value that maintains horizontality (step ST2). In addition, the main controller 30 calculates the deviation between the set lifting height target value and the current lifting height successively detected by the lifting height detection unit 41 (step ST3).

[0033] After the horizontal movement mode is set, the system waits for operation input for hoisting / extension (step ST4). Until an operation input is detected, the winch 13 does not operate, and the winch rotation speed is set to 0 (step ST11). In this example, in order to simplify software control during horizontal movement of the hook, only one operation that is performed first from the neutral state is allowed, and multiple operations are restricted from being allowed. For this reason, after the horizontal movement mode is set, when a lever operation input for hoisting / extension is detected (step ST4), the system stops all lever operation inputs for hoisting / extension other than the lever operation input that was detected first until the operating levers 24, 25 return to the neutral position (step ST5). Note that winch lifting / lowering and rotation are allowed.

[0034] If the detected lever operation input for hoisting / retraction is the first input after the start of feedback control of horizontal movement (step ST6), the initial speed of the winch 13 is calculated based on the boom length and the number of ropes attached, and set as an offset value (step ST7). For example, the winch initial speed is set as follows. If the boom length is x and the winch initial speed coefficients for n ropes attached are an and bn, the initial output value to the winch solenoid valve that specifies the winch initial speed is set to anx+bn. The winch initial speed coefficients an and bn (6-rod a6, b6, 4-rod a4, b4, 2-rod a2, b2, 1-rod a1, b1) are values ​​determined experimentally. Also, the feedback control coefficients are allocated based on the number of ropes attached (step ST8). In other words, the proportional gain is increased as the number of ropes attached increases. After this, the main controller 30 starts feedback control of the horizontal movement of the hook 16, and performs feedback control of the winding and unwinding operation of the wire rope 14 by the winch 13 so that the deviation between the detected lifting height and the target lifting height value is eliminated even when the boom 11 is being raised or lowered.

[0035] First, while the lever operation input of "raising" or "extending" is detected for the raising and retracting of the boom 11 (step ST9), the deviation of the current lifting height from the lifting height target value is used as a feedback value, and PI control of the lowering speed of the winch 13 is performed with the deviation of 0 as the target value (step ST9-1). Of course, PID control can also be adopted as the feedback control form. In the control of this example, when the absolute value of the deviation becomes larger than a preset value, for example, 10 cm, that is, when the deviation (= lifting height target value-current lifting height) becomes smaller than -10 cm during the winch lowering operation (wire rope unwinding operation) (step ST9-2), the rotation speed of the winch 13 is slowed down or increased in proportion to the deviation (step ST9-3).

[0036] More specifically, in this example, a 10-time moving average of the deviation being fed back is used as the deviation. By using the moving average of the deviation, it is possible to smooth out fluctuations in the deceleration rate in the deceleration control of the rotational speed of the winch, which are caused by fluctuations in the deviation, thereby making it possible to prevent the occurrence of hunting and ensure the stability of the control. Of course, the moving average of the deviation used is not limited to the 10-time moving average.

[0037] Furthermore, in the deceleration control (step ST9-3) of the winch 13 when the moving average of the deviation becomes smaller than -10 cm (when the absolute value becomes larger than 10 cm), for example, when the actual deviation is 10 cm to 60 cm with respect to the target deviation of "0" cm, if the initially set winch rotation speed is 100%, the deviation remains 100% between 0 and -10 cm, and the rotation speed is reduced to 100% to 0% in proportion to the deviation between -10 cm and -60 cm. If the deviation exceeds -60 cm, the winch rotation speed is set to 0%, and the winch lowering operation is not performed.

[0038] Similarly, while detecting the operation input of "lower" or "retract" of the boom 11 (step ST10), the deviation of the current lifting height from the lifting height target value is used as a feedback value, and PI control of the lowering speed of the winch 13 is performed with the deviation of 0 as the target value (step S10-1). Also, when the absolute value of the deviation becomes larger than a preset value, for example, 10 cm, that is, when the deviation (= lifting height target value-current lifting height) becomes larger than +10 cm during the winch winding operation (wire rope winding operation) (step ST10-2), the rotation speed of the winch 13 is decelerated in proportion to the deviation (step ST10-3). In this case as well, the deviation is calculated by moving the deviation fed back 10 times and averaging it. In addition, in the deceleration control of winch 13 (step ST10-3) when the moving average of the deviation becomes larger than +10 cm, if the actual deviation is +10 cm to +60 cm with respect to the target deviation of "0" cm, the winch rotation speed initially set to 100% is maintained at 100% when the deviation is between 0 and +10 cm, and the rotation speed is reduced from 100% to 0% in proportion to the deviation when the deviation is between +10 cm and +60 cm. When the deviation exceeds +60 cm, the winch rotation speed is set to 0%, and the winch winding operation is not performed.

[0039] Next, in the horizontal movement mode, during the lowering operation of the boom 11, the upper limit of the lowering operation speed is regulated in proportion to the length of the boom 11 (step ST12). For example, during the lowering operation, the output value to the solenoid on the lowering side of the electromagnetic changeover valve that controls the supply of hydraulic oil to the hydraulic motor for driving the winch in the hydraulic device 36 is limited in proportion to the boom length, the longer the boom length is. For example, if the maximum output value is 100%, the output is regulated to 100% (the ratio of the upper limit of the output to the current that can be output) when the boom is fully retracted, and to 66% (the ratio of the upper limit of the output to the current that can be output) when the boom is fully extended.

[0040] In contrast, during the operation of raising the boom 11, the upper limit of the raising operation speed is always regulated by a fixed regulation value (step ST13). For example, the output value to the solenoid on the raising side of the electromagnetic change-over valve that controls the supply of hydraulic oil to the boom hoist cylinder in the hydraulic device 36 is limited at a fixed rate. As one example, it is limited to 67.5% (the ratio of the output upper limit to the outputtable current).

[0041] Furthermore, during boom extension operation during boom telescoping operation, when the boom 11 is longer than four stages, the upper limit of the extension operation speed is regulated by a certain regulated value (step ST14). That is, when the number of boom stages being extended is four or five (the number of stages that are extended and contracted simultaneously), the output value to the extension-side solenoid is limited by a certain ratio. For example, when the boom length meter 44 indicates that the boom length is longer than 12.36 m, it is determined that the boom is being extended with four or more stages, and the output value is limited to, for example, 72% (the ratio of the upper output limit to the current that can be output).

[0042] The above-described feedback control operation for horizontal movement is repeated until the horizontal movement mode is released. As a result, in the horizontal movement mode, the operator can move the hook 16 horizontally simply by operating the lever to raise and lower the boom 11.

[0043] (Translation mode) Next, FIG. 5 is a schematic flow chart showing the operation of the mobile crane 1 in the parallel movement mode. When the operator operates the mode selection button 27a on the display operation panel 27 to select the parallel movement mode, the main controller 30 sets the control mode to the parallel movement mode (step ST21). In addition, the main controller 30 sets the current hook suspension length (the distance from the tip of the boom to the bottom end of the hook 16) detected by the hook suspension length detection unit 42 to the suspension length target value for maintaining parallelism (step ST22). After this, the main controller 30 sequentially detects the current suspension length, obtains the deviation between the detected current suspension length and the suspension length target value (step ST23), and performs feedback control of the parallel movement so that the deviation becomes zero.

[0044] In the feedback control of translation, the winch rotation speed is set to 0 until a lever operation input for boom extension / retraction is detected (step ST29). When a lever operation input for boom extension / retraction is detected (step ST24), if this is the first operation input after feedback control has started (step ST25), the initial speed of the winch 13 for winding and unwinding the rope is set to a predetermined constant value (step ST26). For example, the initial output value to the winch solenoid valve that determines the winch initial speed is set to anx+bn. As mentioned above, x is the boom length (m), and an and bn are the winch initial speed coefficients when n booms are hung.

[0045] When the boom telescopic lever operation input is the "extend" operation input (step ST27), the deviation of the current suspension length from the target suspension length value is used as a feedback value, and PI control of the lowering speed of the winch 13 is performed with a target deviation of 0 (step ST27-1). As a feedback control form, it is of course possible to adopt PID control.

[0046] Similarly, when the boom telescopic lever operation input is "retract" (step ST28), the deviation of the current suspension length from the target suspension length value is used as a feedback value, and PI control of the hoisting speed of the winch 13 is performed with a deviation of 0 as the target value (step ST28-1). As the feedback control form, it is of course possible to adopt PID control.

[0047] Next, during the extension operation of the boom 11, if the number of boom stages being extended is four or more (the number of stages being extended simultaneously), the output value to the extension-side solenoid is limited at a certain rate (step ST30). For example, when the boom length meter 44 indicates that the boom length is greater than 12.36 m, it is determined that the boom is being extended at four or more stages, and the output value is limited to, for example, 72% (the rate of the upper output limit to the current that can be output).

[0048] The above-described feedback control operation for the parallel movement is repeated until the parallel movement mode is released. As a result, in the parallel movement mode, the operator can translate the hook 16 by simply inputting the lever operation input for extending and retracting the boom 11.

[0049] (Boom length calibration, lifting height calibration) In the feedback control of horizontal movement and translation movement, it is necessary to accurately detect the hook suspension length and lifting height. In order to accurately detect the hook suspension length, the main controller 30 in this embodiment calibrates the rope length with the rope unwound from the winch drum. For example, when an operation input is made to perform calibration from the display operation panel 27, the main controller 30 starts the calibration operation, displays the calibrated boom posture on the display screen 27c, and drives and controls the winch 13 to unwind the rope from the winch drum and calibrate the winding amount.

[0050] On the other hand, automatic lifting height calibration is performed when the boom is in a specific posture. For example, when the main controller 30 is in an unloaded state where no crane work is being performed, the boom is fully retracted, and the boom angle is at a preset angle, the main controller 30 executes an interrupt process for automatic lifting height calibration when the hook overwinding sensor 46 attached to the end of the boom turns on. Calibration is performed so that the lifting height detected by the lifting height detection unit 41 at the time when the hook overwinding sensor 46 turns on matches the lifting height in the specific posture that is preset. This makes it possible to eliminate lifting height errors caused by winch drum rotation detection errors. [Explanation of symbols]

[0051] 1 Mobile crane 2 Undercarriage 3 Telescopic boom 4. Upper rotating body 5 Truck Frame 6 sprockets 8. Crawler 11. Boom 12 Boom derrick cylinder 13. Winch 14 Wire Rope 15 Hook Block 16 Hook 17 Cabin 21 Safety lock lever 22, 23 Travel lever 24 Left work equipment operation lever 25 Right work equipment operation lever 26 Accelerator pedal 27 Display operation panel 27a Mode selection button 27b Number input button 27c display screen 30 Main Controller 31 Driving Controller 32 Boom extension device 33 Boom hoisting device 34 Swivel 35 Running gear 36 Hydraulic system 37 Engine 41 Lift detection unit 42 Hook hanging length detector 43 Boom angle gauge 44 Boom length gauge 45 Potentiometer (rotation angle detection part) 46 Hook overwinding sensor 47 Rotational speed sensor 50 Radio Control 51 Display section 52 Mode selection button 53 Swing operation switch 54 Boom telescopic switch 55 Boom hoisting operation switch 56 Winch operation switch 60 Transmitting and Receiving Device 71 Control Unit 72 Memory section 73 Operation mode setting section 74 Target value setting section 75 Feedback control section

Claims

1. A method for controlling the movement of a hook of a crane, the method comprising the steps of: controlling the movement of a hook suspended by a wire rope from the tip of a boom by a controller mainly composed of a computer; A horizontal movement mode for controlling the horizontal movement of the hook based on an external input operation is set as an operation mode, and a lifting height target value for the horizontal movement is set; In the horizontal movement mode, feedback control is performed to wind and unwind the wire rope in synchronization with the raising and lowering operation of the boom performed based on an external input operation so that the current position of the hook maintains the lifting height target value; In the feedback control of the horizontal movement mode, an initial speed of a winch for winding and unwinding the wire rope is calculated based on the length of the boom at the start of control and the number of loops of the wire rope that is input and set in advance, and the winch is rotationally driven at the initial speed to start the winding and unwinding operation of the wire rope; In the feedback control of the horizontal movement mode, when the absolute value of the deviation between the current position of the hook and the target lifting height value is greater than a preset value, the greater the absolute value of the deviation, the slower or faster the rotational speed of the winch is from the initial speed.

2. In claim 1, A method for controlling movement of a crane hook, the method using a moving average value for a predetermined number of times as the absolute value of the deviation.

3. A method for controlling the movement of a hook of a crane, the method comprising the steps of: controlling the movement of a hook suspended by a wire rope from the tip of a boom using a controller mainly composed of a computer; A horizontal movement mode for controlling the horizontal movement of the hook based on an external input operation is set as an operation mode, and a lifting height target value for the horizontal movement is set; In the horizontal movement mode, feedback control is performed to wind and unwind the wire rope in synchronization with the raising and lowering operation of the boom performed based on an external input operation so that the current position of the hook maintains the lifting height target value; In the feedback control of the horizontal movement mode, the length of the boom at the start of the control and calculating an initial speed of a winch for winding and unwinding the wire rope based on a number of loops of the wire rope that is input and set in advance, and rotating and driving the winch at the initial speed to start the winding and unwinding operation of the wire rope; In the feedback control of the horizontal movement mode, The upper limit value of the boom lowering motion speed is regulated to a lower value as the length of the boom increases, A hook movement control method for a crane, which restricts an upper limit of the starting operation speed of the boom to a value that is lower by a certain percentage than a preset upper limit of the starting operation speed.

4. A method for controlling the movement of a hook of a crane, the method comprising the steps of: controlling the movement of a hook suspended by a wire rope from the tip of a boom using a controller mainly composed of a computer; A horizontal movement mode for controlling the horizontal movement of the hook based on an external input operation is set as an operation mode, and a lifting height target value for the horizontal movement is set; In the horizontal movement mode, feedback control is performed to wind and unwind the wire rope in synchronization with the raising and lowering operation of the boom performed based on an external input operation so that the current position of the hook maintains the lifting height target value; In the feedback control of the horizontal movement mode, an initial speed of a winch for winding and unwinding the wire rope is calculated based on the length of the boom at the start of control and the number of loops of the wire rope that is input and set in advance, and the winch is rotationally driven at the initial speed to start the winding and unwinding operation of the wire rope; In the feedback control of the horizontal movement mode, When the boom extension operation is performed sequentially for each stage in a number of stages equal to or less than a predetermined number of stages, an upper limit value of the extension operation speed is set to a preset upper limit value of the extension operation speed, A crane hook movement control method for restricting an upper limit of the extension speed to a value that is a certain percentage lower than the upper limit of the extension speed when boom extension operations of each stage are performed simultaneously at a stage higher than a predetermined number of stages.

5. A method for controlling the movement of a hook of a crane, the method comprising the steps of: controlling the movement of a hook suspended by a wire rope from the tip of a boom by a controller mainly composed of a computer, A horizontal movement mode for controlling the horizontal movement of the hook based on an external input operation is set as an operation mode, and a lifting height target value for the horizontal movement is set; In the horizontal movement mode, feedback control is performed to wind and unwind the wire rope in synchronization with the raising and lowering operation of the boom performed based on an external input operation so that the current position of the hook maintains the lifting height target value; In the feedback control of the horizontal movement mode, an initial speed of a winch for winding and unwinding the wire rope is calculated based on the length of the boom at the start of control and the number of loops of the wire rope that is input and set in advance, and the winch is rotationally driven at the initial speed to start the winding and unwinding operation of the wire rope; The controller further sets the control mode to a parallel movement mode in which control is performed to translate the hook, and sets a target suspension length value for the parallel movement, based on an external input operation. In the parallel movement mode, when the boom is extended or retracted by an external input operation, feedback control is performed to wind and unwind the wire rope so that the current position of the hook maintains the target suspension length value; When the boom extension operation is performed sequentially for each stage in a number of stages equal to or less than a predetermined number of stages, an upper limit value of the extension operation speed is set to a preset upper limit value of the extension operation speed, When the booms of each stage are extended simultaneously at a stage higher than a predetermined stage, the upper limit of the extension speed is restricted to a value lower than the upper limit of the extension speed by a certain percentage. A method for controlling the movement of a crane hook.

6. A method for controlling the movement of a hook of a crane, the method comprising the steps of: controlling the movement of a hook suspended by a wire rope from the tip of a boom using a controller mainly composed of a computer, A horizontal movement mode for controlling the horizontal movement of the hook based on an external input operation is set as an operation mode, and a lifting height target value for the horizontal movement is set; In the horizontal movement mode, feedback control is performed to wind and unwind the wire rope in synchronization with the raising and lowering operation of the boom performed based on an external input operation so that the current position of the hook maintains the lifting height target value; In the feedback control of the horizontal movement mode, an initial speed of a winch for winding and unwinding the wire rope is calculated based on the length of the boom at the start of control and the number of loops of the wire rope that is input and set in advance, and the winch is rotationally driven at the initial speed to start the winding and unwinding operation of the wire rope; A crane hook movement control method in which, prior to the feedback control, the amount of the wire rope unwound and wound is calibrated while the wire rope is unwound from the winch.

7. A method for controlling the movement of a hook of a crane, the method comprising the steps of: controlling the movement of a hook suspended by a wire rope from the tip of a boom by a controller mainly composed of a computer, A horizontal movement mode for controlling the horizontal movement of the hook based on an external input operation is set as an operation mode, and a lifting height target value for the horizontal movement is set; In the horizontal movement mode, feedback control is performed to wind and unwind the wire rope in synchronization with the raising and lowering operation of the boom performed based on an external input operation so that the current position of the hook maintains the lifting height target value; In the feedback control of the horizontal movement mode, an initial speed of a winch for winding and unwinding the wire rope is calculated based on the length of the boom at the start of control and the number of loops of the wire rope that is input and set in advance, and the winch is rotationally driven at the initial speed to start the winding and unwinding operation of the wire rope; A hook movement control method for a crane, which performs automatic lifting height calibration to match a detection value indicating the current position of the hook with a preset value when the boom is fully retracted at a preset angle and a hook overwinding detection sensor attached to the tip of the boom is on.

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