Lifting device and crane

Abstract

A ground clearance control device is mounted on a crane having an arm and a hoist having a lifting cable, and controls the ground clearance of a hoisted load. The ground clearance control device includes a load detecting section that detects a load acting on the arm, and a control section that controls the lifting operation of the hoist and the raising operation of the arm. The control section controls the raising of the arm to suppress the swing of the hoisted load by using a control signal that is generated based on the time variation of the detected value of the load detecting section and that is obtained by applying a filter that attenuates the frequency components in a predetermined range.

Description

Technical Field

[0001] This invention relates to a lifting control device and a crane for suppressing load sway when lifting loads from the ground. Background Technology

[0002] Previously, in cranes with booms, when lifting loads from the ground, i.e., when lifting loads off the ground, the boom's deflection increases the working radius, causing "load sway"—a problem where the lifted load swings horizontally (see reference). Figure 1 ).

[0003] For the purpose of preventing load swaying when lifted off the ground, for example, the vertical lifting control device described in Patent Document 1 is configured such that the engine rotation number is detected by an engine rotation number sensor, and the arm lifting action is corrected to a value corresponding to the engine rotation number.

[0004] Prior art literature

[0005] Patent documents

[0006] Patent Document 1: Japanese Patent Application Publication No. 8-188379 Summary of the Invention

[0007] The problem that the invention aims to solve

[0008] Furthermore, conventional ground-lifting control devices, including Patent Document 1, use both winch actuators and undulation actuators for control in order to maintain a constant operating radius. This results in increased time consumption due to the complexity of the control process.

[0009] Therefore, the object of the present invention is to provide a ground lifting control device capable of suppressing load sway and rapidly lifting the load off the ground, and a crane equipped with the ground lifting control device.

[0010] Methods for solving problems

[0011] One aspect of the lifting-off-ground control device involved in this invention is as follows:

[0012] A ground lifting control device is mounted on a crane equipped with a winch having an arm and a lifting cable, and controls the lifting load from the ground. The ground lifting control device comprises:

[0013] The load testing unit measures the load applied to the arm; and

[0014] The control unit controls the hoisting action and boom tilting action of the winch.

[0015] The control unit controls the boom's tilting to suppress the swaying of the lifting load by using the following control signal, which is generated based on the time variation of the load detection value and obtained by applying a filter that attenuates frequency components within a specified range.

[0016] Invention Effects

[0017] According to the present invention, a ground lifting control device capable of suppressing load sway and rapidly lifting the load off the ground, and a crane equipped with the ground lifting control device are provided. Attached Figure Description

[0018] Figure 1 This is an explanatory diagram illustrating the load swing of the lifting load.

[0019] Figure 2 This is a side view of a mobile crane.

[0020] Figure 3 This is a block diagram of the control device for lifting the device off the ground.

[0021] Figure 4 This is a block diagram of the overall control device for lifting off the ground.

[0022] Figure 5 This is a diagram showing the control mechanism for lifting the crane off the ground.

[0023] Figure 6 This is a block diagram related to the application of band-domain removal filters.

[0024] Figure 7 This is a flowchart of the control process for lifting the object off the ground.

[0025] Figure 8 It is a graph illustrating the method for determining whether a object is lifted off the ground.

[0026] Figure 9 It is a graph showing the relationship between load and undulation angle.

[0027] Figure 10 This is an explanatory diagram of the characteristics of a notch filter. Detailed Implementation

[0028] Hereinafter, an example of an embodiment of the present invention will be described with reference to the accompanying drawings. However, the structural elements described in the following embodiment are illustrative and are not intended to limit the scope of the present invention to this.

[0029] [Implementation Method]

[0030] In this embodiment, examples of mobile cranes include complex terrain cranes, all-terrain cranes, and truck cranes. Hereinafter, a complex terrain crane will be used as an example of the working vehicle involved in this embodiment, but the lifting-off-ground control device according to this invention can also be applied to other mobile cranes. Furthermore, the lifting-off-ground control device according to this invention can also be applied to crawler cranes or tower cranes.

[0031] (Structure of a mobile crane)

[0032] First, use Figure 2 The structure of the mobile crane is described. The complex terrain crane 1 of this embodiment is as follows: Figure 2 As shown, the vehicle includes a body 10, which is the main body of the vehicle with driving function, outriggers 11 provided at the four corners of the body 10, a turntable 12 that is mounted on the body 10 in a way that allows it to rotate horizontally, and an arm 14 that is mounted on the rear of the turntable 12.

[0033] The outrigger 11 can slide out / slide back from the vehicle body 10 in the width direction by extending and retracting the sliding cylinder, and can extend / retract the jack from the vehicle body 10 in the up and down direction by extending and retracting the jack cylinder.

[0034] The rotary table 12 has a pinion gear that transmits power to the rotary motor 61. This pinion gear meshes with a circular gear on the vehicle body 10, thereby rotating around the rotary axis. The rotary table 12 has an operator's seat 18 located at the front right and a counterweight 19 located at the rear.

[0035] Furthermore, a winch 13 for lifting and lowering the steel cable 16 is arranged behind the rotary table 12. The winch 13 causes the winch motor 64 to rotate in the forward or reverse direction, thereby rotating in two directions: the lifting direction (winding direction) or the lowering direction (turning out direction).

[0036] The arm 14 is nested together with a base arm 141, (one or more) intermediate arms 142, and a front arm 143, and is extended and retracted by an internally configured telescopic cylinder 63. A pulley is provided at the foremost arm head 144 of the front arm 143, and a steel cable 16 is wound around the pulley and a hook 17 is suspended from it.

[0037] The base end of the base arm 141 is rotatably mounted on a support shaft provided on the rotary table 12. The base arm 141 can move up and down about the support shaft as the center of rotation. In addition, an undulating cylinder 62 is provided between the rotary table 12 and the lower surface of the base arm 141. By extending and retracting the undulating cylinder 62, the arm 141 moves up and down as a whole.

[0038] (Structure of the control system)

[0039] Next, use Figure 3 The block diagram illustrates the structure of the control system of the lifting-off-ground control device D according to this embodiment. The lifting-off-ground control device D is centered around a controller 40, which serves as the control unit. The controller 40 is a general-purpose microcomputer with input ports, output ports, and an arithmetic unit. The controller 40 receives operation signals from the operating levers 51-54 (rotation lever 51, undulation lever 52, telescopic lever 53, and winch lever 54) and controls the actuators 61-64 (rotation motor 61, undulation cylinder 62, telescopic cylinder 63, and winch motor 64) via control valves (not shown).

[0040] Furthermore, the controller 40 in this embodiment is connected to: a ground lift switch 20A for starting or stopping the ground lift control; a winch speed setting mechanism 20B for setting the speed of the winch 13 during ground lift control; a pressure gauge 21, which serves as a load detection unit for detecting the load acting on the boom 14; an attitude measurement mechanism 23 for detecting the attitude information of the boom 14; and a rotation count meter 22 for measuring the number of rotations of the winch 13. The attitude measurement mechanism 23 is an example of an attitude detection unit.

[0041] The ground lift switch 20A is an input device used to indicate the start or stop of ground lift control. The ground lift switch 20A can also be configured as a safety device attached to the crane 1 in complex terrain. The ground lift switch 20A is preferably located at the control station 18.

[0042] The winch speed setting mechanism 20B is an input device used to set the speed of the winch 13 during ground lifting control. The winch speed setting mechanism 20B has a mechanism for selecting an appropriate speed from a preset speed, or a mechanism for inputting the speed via numeric keys. Furthermore, like the ground lifting switch 20A, the winch speed setting mechanism 20B can be configured as a safety device attached to the crane 1 in complex terrain. The winch speed setting mechanism 20B is preferably located on the control seat 18. By adjusting the speed of the winch 13 using this winch speed setting mechanism 20B, the time required for ground lifting control can be adjusted.

[0043] The pressure gauge 21, which serves as the load detection unit, is a measuring device that measures the load acting on the arm 14. For example, the pressure gauge 21 measures the pressure acting on the hydraulic cylinder 62. The pressure signal measured by the pressure gauge 21 is transmitted to the controller 40.

[0044] Rotation speed meter 22 is positioned near the rotating shaft of winch (drum) 13 to measure the rotation speed (rotation rate) of winch (drum) 13. The rotation speed (rotation rate) measured by rotation speed meter 22 is transmitted to controller 40 and used to calculate winch lifting speed and cable length.

[0045] The attitude measurement mechanism 23 is a measuring device for detecting the attitude information of the arm 14, and consists of an undulation angle meter 231 for measuring the undulation angle of the arm 14 and an undulation angular velocity meter 232 for measuring the undulation angular velocity. Specifically, the undulation angle meter 231 is, for example, a potentiometer. The undulation angular velocity meter 232 is, for example, a stroke sensor mounted on the undulation cylinder 15. The undulation angle signal measured by the undulation angle meter 231 and the undulation angular velocity signal measured by the undulation angular velocity meter 232 are transmitted to the controller 40.

[0046] The controller 40 is a control unit that controls the movement of the boom 14 and the winch 13. When the lifting load is lifted off the ground by setting the lift-off switch 20A to ON, the controller 40 predicts the change in the undulation angle of the boom 14 based on the time change of the load measured by the pressure gauge 21, which is a load detection unit, and tilts the boom 14 to compensate for the predicted change.

[0047] More specifically, the controller 40, corresponding to one example of the control unit, has a characteristic table or transfer function selection function 40a and a ground lifting determination function 40b that stops the ground lifting control by determining whether the ground lifting has actually been lifted off the ground.

[0048] The characteristic table or transfer function selection unit 40a receives initial values ​​of pressure from the pressure gauge 21 (which is a load detection unit) and initial values ​​of fluctuation angle from the fluctuation angle gauge 231 (which is an attitude detection unit), and determines the characteristic table or transfer function to be applied. Here, a relationship using a linear coefficient 'a' can be applied as the transfer function, as follows.

[0049] First, such as Figure 9 As shown in the load-fluctuation angle curve, it can be seen that when the boom tip position is always directly above the lifting load to prevent load swaying, the load and the fluctuation angle (the angle of the front end relative to the ground) have a linear relationship. During the lifting off the ground, if we assume that the load Load1 changes to Load2 between time t1 and time t2, then the relationships between the fluctuation angle θ and the load Load, the fluctuation angle θ1 and the load Load1, and the fluctuation angle θ2 and the load Load2 are expressed by the following formulas.

[0050] [Number 1]

[0051] Approximate formula θ = a·Load + b

[0052] t1 θ1=a·Load1+b

[0053] t2 θ2=a·Load2+b

[0054] The difference between the two equations is expressed by the following equation through the difference equation.

[0055] [Number 2]

[0056] θ2-θ1=a(Load2-Load1)

[0057] Δθ=a·ΔLoad

[0058] In order to control the undulation angle, the undulation angular velocity needs to be given by the following formula.

[0059] [Number 3]

[0060]

[0061] Here, 'a' is a constant (linear coefficient).

[0062] That is, the fluctuation angle control takes the time change (derivative) of the load as input.

[0063] The lift-off-ground determination function 40b monitors time-series data of the load value calculated from the pressure signal from the pressure gauge 21, which is a load detection unit, to determine whether the object has been lifted off the ground. Regarding the method for determining lift-off-ground status, the following is used... Figure 8 To be discussed later.

[0064] (Overall frame diagram)

[0065] Next, use Figure 4 The diagram below provides a detailed explanation of the input / output relationships between elements encompassing the lifting-off-ground control described in this embodiment. First, in the load change calculation unit 71, the load change is calculated based on the time-series data of the load measured by the pressure gauge 21, which serves as the load detection unit. The calculated load change is then input to the target shaft speed calculation unit 72. Regarding the input / output relationships in this target shaft speed calculation unit 72, the following diagram is used... Figure 5 To be discussed later.

[0066] In the target shaft speed calculation unit 72, the target shaft speed is calculated based on the initial value of the undulation angle, the set winch speed, and the input load change. The target shaft speed here refers to the target undulation angular velocity (and the target winch speed, though these are not mandatory). The calculated target shaft speed is input to the shaft speed controller 73. This first part of the control is related to the lifting-off-ground control process of this embodiment.

[0067] Subsequently, after passing through the shaft speed controller 73 and the shaft speed operation quantity conversion processing unit 74, the operation quantity is input to the controlled object 75. This latter part of the control is a process related to normal control, and feedback control is performed based on the measured fluctuating angular velocity.

[0068] (Brief diagram of control for lifting off the ground)

[0069] Next, use Figure 5 The diagram below explains the input / output relationships of elements in the target axis velocity calculation unit 72 for lifting off the ground. First, the initial value of the undulation angle is input to the characteristic table / transfer function selection unit 81 (40a). In the selection function unit 81, the most appropriate constant (linear coefficient) a is selected using the characteristic table (LookupTable) or the transfer function (formula).

[0070] Furthermore, in the numerical differentiation section 82, a numerical differentiation of the load change (a time-dependent differentiation) is performed, and the result of this numerical differentiation is multiplied by a constant a to calculate the target undulation angular velocity. That is, the target undulation angular velocity is calculated by performing the calculation described in Equation 3 above. In this way, the target undulation angular velocity is controlled by feedforward using a characteristic table (or transfer function).

[0071] (Block diagram of the application of the band-domain removal filter)

[0072] Next, use Figure 6 The diagram illustrates the operation of applying a band removal filter that attenuates a specified band when generating a control signal for the fluctuating angular velocity based on a target fluctuating angular velocity (target value of fluctuating angular velocity). First, via a start command, the first control signal generation unit 91 instructs the crane 93 (winch motor 64), which is the controlled object, to maintain the speed of the winch 13 at a constant rotational speed γd. This winch speed control is based on feedback control using the measured cable length. The measured cable length is used, on the other hand, to determine whether the cable is lifted off the ground, thus triggering the activation of the filter application unit 95.

[0073] Subsequently, the second control signal generation unit 92, based on the target fluctuation angle θd and the measured fluctuation angular velocity, instructs the PID control unit 94 to generate a target fluctuation angular velocity. The PID control unit 94 generates a fluctuation angular velocity control signal through PID control. That is, the fluctuation angular velocity control signal is generated based on the difference between the measured fluctuation angular velocity and the target fluctuation angular velocity. This fluctuation angular velocity control is feedback-controlled based on the measured load and the measured fluctuation angular velocity (see reference). Figure 4 , Figure 5The measured load (pressure value) is used on the other hand to determine whether the object is lifted off the ground, thus triggering the start of the filter application unit 95.

[0074] Then, the controller 40 determines whether the cable has been lifted off the ground based on timing data of the measured cable length or timing data of the measured load (pressure value). If the controller 40 determines that lifting off the ground is complete, the filter application unit 95 applies a band removal filter that attenuates a specified band to the undulation angular velocity control signal. If the controller 40 determines that lifting off the ground is incomplete, the filter application unit 95 does not apply the band removal filter to the undulation angular velocity control signal. Alternatively, the filter application unit 95 may always apply the band removal filter to the undulation angular velocity control signal regardless of whether lifting off the ground is complete.

[0075] Therefore, a band-stop filter is applied when generating the fluctuating angular velocity control signal. A band-stop filter has the frequency characteristic of allowing most frequencies to pass as is while attenuating only a specified range of frequency components to a very low level. A notch filter with a narrow stopband is preferably used as the band-stop filter. Furthermore, in the following embodiments, a specific example using a notch filter is described, but this is only one example; other band-stop filters can also be used.

[0076] Here, in Figure 10 The diagram illustrates the characteristics of a notch filter. For example... Figure 10 As shown, if a notch filter is applied, the amplitude is significantly attenuated before and after the center frequency. If a notch filter is applied, a phase delay characteristic is observed at lower frequencies than the center frequency, while a phase lead characteristic is observed at higher frequencies. The natural vibration frequency of arm 14 varies depending on the state of arm 14. The state of arm 14 is, for example, the length of arm 14 and / or the extension / retraction mode of arm 14. That is, even if the length of arm 14 is the same, the natural vibration frequency of arm 14 will be different depending on the extension / retraction mode. In mobile cranes, it is preferable to calculate / measure the natural vibration frequency in advance according to the length of arm 14 and / or the extension / retraction mode, and store it. That is, the storage unit of the mobile crane preferably stores the natural vibration frequency in a correspondence with the length of arm 14 and / or the extension / retraction mode. Regarding this natural vibration frequency, it is also preferable to actually measure the natural vibration frequency of each working vehicle in advance at the time of shipment from the factory.

[0077] (flow chart)

[0078] Next, use Figure 7 The flowchart illustrates the overall process of lifting off the ground control in this embodiment.

[0079] First, the operator presses the lift-off switch 20A to initiate lift-off control (START). At this time, either before or after the start of lift-off control, a target speed for the winch 13 is set via the winch speed setting mechanism 20B. Consequently, the controller 40 initiates winch control at the target speed (step S1). This target speed is, for example, a fixed speed.

[0080] Next, while the winch 13 is being lifted, the pressure gauge 21, which is the load detection unit, starts to measure the lifting load (pressure detection of the undulating cylinder) and inputs the load value (pressure value) to the controller 40 (step S2).

[0081] Next, in the function selection unit 40a, the initial value of the load value (pressure value) and the initial value of the undulation angle from the undulation angle meter 231, which is the attitude detection unit, are received, and the characteristic table or transfer function to be applied is determined (step S3). Next, in the controller 40, the undulation angular velocity is calculated based on the applied characteristic table or transfer function and the load change (step S3). That is, the undulation angular velocity is controlled by feedforward control.

[0082] Next, the temporal change of the cable length is detected in order to be used in the subsequent determination of lifting off the ground (step S4). Specifically, the cable length is calculated by inputting the rotation number measured by the rotation number meter 22 and the attitude (undulation angle, undulation angular velocity, arm length) measured by the attitude measuring mechanism 23 into the controller 40, and its temporal change is monitored.

[0083] Then, in controller 40, based on the time-series data of the measured load and / or cable length, it is determined whether the cable has been lifted off the ground (step S5). The determination method will be described later. If the determination result is that the cable has not been lifted off the ground (step S5: No), the process returns to step S3, and load-based feedforward control is repeated (steps S3 to S5).

[0084] If the determination result is that the lifting off the ground is complete (step S5: Yes), a notch filter is activated during gradual stopping control (step S6). That is, during the gradual stopping of the undulating motion after lifting off the ground, the controller 40 applies a notch filter (band removal filter) when generating an undulating angular velocity control signal based on the target value of the undulating angular velocity. At this time, a notch filter corresponding to the length of the arm 14 is selected as the notch filter to be applied. Furthermore, regarding the timing of applying this notch filter, it can be applied from the moment it is determined that the lifting off the ground, within a predetermined time or during the period of measuring a predetermined number of vibrations. The generated undulating angular velocity control signal is used in the following step S7.

[0085] Next, the lifting-off-ground control signal is gradually stopped using the undulation angular velocity control signal after applying a notch filter (step S7). That is, the lifting action of the arm 14, performed by the undulation cylinder 62, is gradually reduced in speed and stopped (step S7). Gradual stopping can be achieved, for example, by reducing the angular velocity linearly. In this embodiment, when the undulation drive is reduced in speed and stopped (i.e., when the undulation angular velocity is gradually stopped), vibration is suppressed by moving the arm 14 away from its natural frequency.

[0086] While the natural vibration frequency of the arm 14 varies depending on the arm length, in this embodiment, it can be represented by a function based on measured data, corresponding to any arm length and / or extension / retraction mode. Furthermore, in this embodiment, a feature is that although the rotational speed of the winch 13 and the undulation angle of the undulation cylinder 62 are controlled, the winch 13 operates at a certain speed, and the control object is simply to gradually stop the undulation angle.

[0087] Finally, the rotation drive of winch 13, driven by the winch motor, is reduced in speed and stopped (step S8). Thus, the lifting-off-ground control is completed (END).

[0088] (Judgment 1 for lifting off the ground)

[0089] Next, use Figure 8 The graph illustrates the method for determining whether the load has been lifted off the ground in this embodiment. In this embodiment, during the lifting process of the winch 13, the controller 40 monitors the measured time-series data of the load and captures the initial maximum value of the time-series data to determine whether the load has been lifted off the ground.

[0090] More specifically, such as Figure 8 As shown, generally speaking, the time-series data of the load overshoots the instant it is lifted off the ground, followed by a downshoot, and then progresses in a continuous vibration manner. Therefore, by capturing the moment of the initial peak of the vibration, i.e., the initial maximum value, it is possible to determine that the load has been lifted off the ground. In practice, the moment when the load is determined to have been lifted off the ground, which is the moment when the initial maximum value is recorded, can be considered as a state of slight overshoot due to inertial force.

[0091] also, Figure 8The load data shown are the measured values ​​of pressure gauge 21 or values ​​calculated based on the measured values ​​of pressure gauge 21 (hereinafter referred to as "measured values ​​of pressure gauge 21"). That is, the measured values ​​of pressure gauge 21 change (vibrate) by repeatedly moving up and down after being lifted off the ground. This change (vibration) in the measured values ​​of pressure gauge 21 is affected by the natural vibration frequency of arm 14. Therefore, the natural vibration frequency of arm 14 can also be calculated based on the change (vibration) in the measured values ​​of pressure gauge 21. The natural vibration frequency calculated in this way can also be used as the center frequency in the described bandgap filter (notch filter).

[0092] (Judgment 2: Lifting off the ground)

[0093] Unlike the methods described above, the controller 40 in this embodiment can also be configured such that, in the control of lifting off the ground, when the winch 13 is used to lift the lifting load off the ground, the determination of lifting off the ground is based on the time change of the measured load and the time change of the measured cable length.

[0094] Specifically, when the controller 40, which is the control unit, lifts the winch 13 to hoist the load off the ground, it uses the cable length at the moment when the measured load begins to change as the initial cable length. When the cable length becomes shorter than the threshold set according to the initial cable length, it determines that the load has been lifted off the ground.

[0095] Alternatively, when the controller 40, as the control unit, lifts the winch 13 to hoist the load off the ground, it uses the time change of the cable length at the moment when the load begins to change as the initial lifting speed. When the time change of the cable length, i.e. the lifting speed, becomes faster than the threshold set according to the initial lifting speed, it determines that the load has been lifted off the ground.

[0096] (Effect)

[0097] Next, the effects of the lifting control device D in this embodiment will be described in detail.

[0098] (1) As described above, the ground lifting control device D of this embodiment includes an arm 14, a winch 13, a pressure gauge 21, and a controller 40, which is a control unit for controlling the arm 14 and the winch 13. When the winch 13 is raised to lift the lifting load off the ground, the controller 40 calculates the change in the undulation angle of the arm 14 based on the measured time change of the load, and raises the arm 14 to compensate for the change. During the gradual cessation of the undulation movement after lifting off the ground, the controller 40 applies a band removal filter that attenuates a specified band when generating an undulation angular velocity control signal based on a target value of the undulation angular velocity. Due to this structure, a ground lifting control device D that can suppress load swaying and quickly lift the lifting load off the ground is realized.

[0099] In other words, in the lifting control device D of this embodiment, considering that the relationship between the load and the undulation angle compensation is linear, feedforward control is implemented based solely on the time change of the load value, and the lifting load can be lifted off the ground quickly without the need for complex feedback control as in the past.

[0100] Then, in the lifting-off-ground control device D of this embodiment, especially when it is determined that the arm has been lifted off the ground and the undulation angular velocity gradually stops, vibration is suppressed by moving the arm 14 in a manner that avoids the natural vibration frequency of the arm 14 by using a function of the natural vibration frequency corresponding to the arm length. Specifically, for example, the vibration is suppressed by gradually stopping the arm 14 and then slowing it down by temporarily increasing the lifting speed of the arm 14.

[0101] (2) In addition, the controller 40 preferably calculates the specified band to be attenuated based on the natural vibration frequency of the arm 14 corresponding to the length of the arm 14. According to such a structure, by attenuating the band around the actual natural vibration frequency of the arm 14, vibration can be effectively suppressed and the lifting control can be quickly terminated.

[0102] (3) Furthermore, after determining that the object has been lifted off the ground, the controller 40 applies the band-domain removal filter only for a specified period of time. With this structure, it is possible to prevent phase delay of angular velocity fluctuations in scenes other than those lifted off the ground.

[0103] (4) In addition, the preferred embodiment also includes an attitude measurement mechanism 23 for detecting the attitude information of the arm 14. The controller 40 selects the corresponding characteristic table or transfer function based on the initial value of the measured attitude of the arm 14 and the initial value of the measured load. Using the characteristic table or transfer function, the controller calculates the change in the undulation angle of the arm 14 according to the time change of the measured load.

[0104] If configured in this way, by raising the winch 13 at a certain speed at the start of the lifting-off-ground control, and calculating the fluctuation angle control amount according to the characteristic table (or transfer function) in accordance with the load change and implementing feedforward control, it is possible to lift the load off the ground quickly without causing it to oscillate. Moreover, since there are few parameters to be adjusted, adjustments can be made quickly and easily during shipment.

[0105] (5) Furthermore, the controller 40 is preferably configured to lift the winch 13 at a constant speed when lifting the load off the ground. If configured in this way, the response (measured load value) can be stabilized by suppressing the effects of disturbances such as inertial forces, making it easier to determine whether the load is off the ground.

[0106] (6) Furthermore, the controller 40 is preferably configured to adjust the speed of the winch 13 when the winch 13 is lifted to lift the load off the ground, thereby adjusting the time required for the load to be lifted off the ground. If configured in this way, by selecting an appropriate speed of the winch 13 in accordance with the weight of the load and the environmental conditions, the operation can be carried out safely and efficiently.

[0107] (7) Furthermore, the controller 40 of this embodiment is configured to monitor the timing data of the measured load when the winch 13 is lifted to lift the lifting load off the ground, and to determine that the load has been lifted off the ground by capturing the initial maximum value of the timing data. By controlling based solely on the load in this way, it is possible to easily and quickly determine that the load has been lifted off the ground.

[0108] (8) Furthermore, the complex terrain crane 1, which is a mobile crane in this embodiment, becomes a complex terrain crane 1 that can suppress load swing and quickly lift the lifting load off the ground by having the ground lifting control device D of any of the above-mentioned ones.

[0109] The embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the specific structure is not limited to these embodiments, and design changes that do not depart from the spirit of the present invention are included in the present invention.

[0110] For example, although not specifically described in the embodiments, the lifting control device D of the present invention can be applied whether the main winch is used as winch 13 to lift the ground or the auxiliary winch is used as winch 13 to lift the ground.

[0111] The entire contents of the specification, drawings and abstract of specification contained in Japanese Patent Application No. 2020-97023, filed on June 3, 2020, are incorporated herein by reference.

[0112] Industrial applicability

[0113] The lifting control device involved in this invention is not limited to mobile cranes, but can be used for various types of cranes.

[0114] Explanation of reference numerals in the attached figures

[0115] D Lifting Control Device

[0116] a. Linear coefficients

[0117] 1. Cranes for complex terrain

[0118] 10. Vehicle body

[0119] 12 rotary tables

[0120] 13. Winch

[0121] 14 arms

[0122] 16 steel cables

[0123] 17 hooks

[0124] 20A Lifted Switch

[0125] 20B Winch Speed ​​Setting Mechanism

[0126] 21 Pressure gauge

[0127] 22 Rotational Count Meter

[0128] 23 Attitude Detection Agency

[0129] 231 Angle Gauge

[0130] 232 Fluctuating Angular Velocity Meter

[0131] 40 Controller

[0132] 40a Select Function Section

[0133] 40b Lifting-off-ground judgment function unit

[0134] 51 Rotary contact rod

[0135] 52. Fluctuating contact rod

[0136] 53 Telescopic contact rod

[0137] 54. Winch contact rod

[0138] 61 Rotary Motor

[0139] 62 undulating hydraulic cylinder

[0140] 63 Telescopic hydraulic cylinder

[0141] 64 winch motor

[0142] 91 First Control Signal Generation Unit

[0143] 92 Second Control Signal Generation Unit

[0144] 93. Crane (Controlled Object)

[0145] 94 PID Control Section

[0146] 95 Filter Application Department

Claims

1. A ground lifting control device mounted on a crane with a boom and a hoisting cable, for controlling the lifting load to be lifted off the ground, the ground lifting control device comprising: The load detection unit detects the load acting on the arm. The control unit, based on control signals, controls the lifting action of the winch and the tilting action of the boom; and The filter application unit applies a filter to the control signal to attenuate frequency components within a specified range. Based on the time-varying load detected by the load detection unit, the control unit predicts the change in the boom's undulation angle required to move the front end of the boom directly above the lifting load, calculates a target undulation angular velocity corresponding to the predicted change in undulation angle, and generates the control signal based on the target undulation angular velocity. If the lifting off the ground is not yet complete, the control unit controls the tilting of the boom using a control signal that is not filtered by the filter application unit to suppress the swaying of the lifting load. Once the lifting off the ground is complete, the control unit stops the arm by controlling the tilting of the arm using the control signal applied by the filter application unit.

2. The lifting control device as described in claim 1, wherein, The filter has frequency characteristics that attenuate the inherent vibration frequency of the arm corresponding to the length of the arm and / or the extension / retraction mode of the arm.

3. The lifting control device as described in claim 1, wherein, The control unit determines that the lifting off the ground is complete when it detects the initial maximum value among the values ​​detected by the load detection unit.

4. The lifting control device as described in claim 1, wherein, The control unit controls the winch during the lifting-off-ground control to ensure that the winch lifts at a constant speed.

5. The lifting control device as described in claim 1, wherein, It also includes an attitude detection unit for detecting the attitude information of the arm. Based on the initial values ​​of the attitude information and the initial values ​​of the load, the control unit selects the corresponding characteristic table or transfer function, and calculates the change in the undulation angle of the arm based on the characteristic table or the transfer function and the time change of the load.

6. A crane comprising a lifting control device according to any one of claims 1 to 5.

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