US-12623886-B2 - Dynamic lift-off control device, and crane

Abstract

A dynamic lift-off control device that is mounted on a crane including a boom and a winch for winding a wire rope and that controls dynamic lift-off of a suspended load, wherein: the dynamic lift-off control device comprises a load detection unit that detects a load acting on the boom, and a control unit that controls a winding action of the winch and a hoisting action of the boom; and the control unit controls the hoisting of the boom by using a control signal, which is generated on the basis of the change over time in the value detected by the load detection unit and to which a filter for attenuating a frequency component in a prescribed range, to suppress swaying of the suspended load is applied.

Inventors

• Yoshimasa MINAMI

Assignees

• TADANO LTD.

Dates

Publication Date

20260512

Application Date

20210603

Priority Date

20200603

Claims (6)

1. 1 . A dynamic lift-off control device that is mounted on a crane including a boom and a winch for winding a wire rope and that controls dynamic lift-off of a suspended load, the dynamic lift-off control device comprising: a load detection unit that detects a load acting on the boom; a control unit that controls a winding action of the winch and a derricking action of the boom based on a control signal; and a filter application unit that applies a filter for dampening a frequency component in a predetermined range to the control signal, wherein the control unit: predicts an amount of change in a derricking angle of the boom required to move a distal end of the boom directly above the suspended load, based on a change over time in the load detected by the load detection unit; calculates a target derricking angular velocity according to the predicted amount of change in the derricking angle; generates the control signal based on the calculated target derricking angular velocity; when the dynamic lift-off has not been completed, controls the derricking action of the boom to suppress horizontal swaying of the suspended load by using the control signal to which the filter is not applied by the filter application unit; and when the dynamic lift-off has been completed, controls the derricking action of the boom to stop the boom by using the control signal to which the filter is applied by the filter application unit, and wherein the load detection unit, the control unit, and the filter application unit are each implemented via at least one processor.
2. 2 . The dynamic lift-off control device according to claim 1 , wherein the filter has a frequency characteristic that dampens a natural frequency of the boom according to a length of the boom and/or a telescopic pattern of the boom.
3. 3 . The dynamic lift-off control device according to claim 1 , wherein the control unit determines that the dynamic lift-off has been completed when a first maximum value in a value detected by the load detection unit is detected.
4. 4 . The dynamic lift-off control device according to claim 1 , wherein the control unit controls the winch to wind the winch at a constant speed in the dynamic lift-off control.
5. 5 . The dynamic lift-off control device according to claim 1 , further comprising a posture detection unit that detects posture information of the boom, wherein the control unit: selects a corresponding characteristic table or transfer function on a basis of an initial value of the posture information and an initial value of the load; and predicts the amount of change in the derricking angle of the boom on a basis of the characteristic table or the transfer function and the change over time in the load, and wherein the posture detection unit is implemented via at least one processor.
6. 6 . A crane comprising the dynamic lift-off control device according to claim 1 .

Description

CROSS REFERENCE TO PRIOR APPLICATION This application is a National Stage Patent Application of PCT International Patent Application No. PCT/JP2021/021225 (filed on Jun. 3, 2021) under 35 U.S.C. § 371, which claims priority to Japanese Patent Application No. 2020-097023 (filed on Jun. 3, 2020), which are all hereby incorporated by reference in their entirety. TECHNICAL FIELD The present invention relates to a dynamic lift-off control device and a crane for suppressing a load swing when lifting a suspended load from the ground. BACKGROUND ART In the related art, in a crane including a boom, when a suspended load is lifted from the ground, that is, when the suspended load is dynamically lifted off, a work radius is increased due to deflection of the boom, so that “load swing” in which the suspended load swings in a horizontal direction has been a problem (see FIG. 1). For the purpose of preventing load swing at the time of dynamic lift-off, for example, a vertical dynamic lift-off control device described in Patent Literature 1 is configured to detect the rotation speed of the engine by an engine rotation speed sensor and correct the hoisting operation of the boom to a value according to the engine rotation speed. CITATION LIST Patent Literature Patent Literature 1: JP 8-188379 A SUMMARY OF THE INVENTION Problems to be Solved by the Invention Meanwhile, in the conventional dynamic lift-off control device including Patent Literature 1, in order to keep the work radius constant, control is performed using a winch actuator and a derricking actuator in combination. Therefore, there is a problem that it takes time to perform the dynamic lift-off due to complicated control. Therefore, an object of the present invention is to provide a dynamic lift-off control device capable of quickly dynamically lifting off the suspended load while suppressing the load swing, and a crane including the dynamic lift-off control device. Solutions to Problems In an aspect of the dynamic lift-off control device according to the present invention, the dynamic lift-off control device is mounted on a crane including a boom and a winch for winding a wire rope and that controls dynamic lift-off of a suspended load, wherein the dynamic lift-off control device includes a load detection unit that detects a load acting on the boom, and a control unit that controls a winding action of the winch and a hoisting action of the boom, and the control unit controls the hoisting of the boom by using a control signal, which is generated on the basis of the change over time in the value detected by the load detection unit and to which a filter for dampening a frequency component in a predetermined range is applied, to suppress swaying of the suspended load. Effects of the Invention According to the present invention, it is possible to provide the dynamic lift-off control device capable of quickly dynamically lifting off the suspended load while suppressing the load swing, and the crane including the dynamic lift-off control device. BRIEF DESCRIPTION OF DRAWINGS FIG. 1 is an explanatory view for explaining load swing of a suspended load. FIG. 2 is a side view of a mobile crane. FIG. 3 is a block diagram of a dynamic lift-off control device. FIG. 4 is as overall block diagram of the dynamic lift-off control device. FIG. 5 is a block diagram of dynamic lift-off control. FIG. 6 is a block diagram related to application of a band removal filter. FIG. 7 is a flowchart of the dynamic lift-off control. FIG. 8 is a graph for explaining a method of a dynamic lift-off determination. FIG. 9 is a graph illustrating a relationship between a load and a derricking angle. FIG. 10 is an explanatory diagram of notch filter characteristics. DESCRIPTION OF EMBODIMENTS Hereinafter, an example of an embodiment according to the present invention will be described with reference to the drawings. However, the components described in the following embodiments are merely examples, and the technical scope of the present invention is not limited thereto. Embodiment In the present embodiment, examples of the mobile crane include a rough terrain crane, an all-terrain crane, and a truck crane. Hereinafter, a rough terrain crane will be described as an example of the work vehicle according to the present embodiment, but the dynamic lift-off control device according to the present invention can also be applied to another mobile crane. Furthermore, the dynamic lift-off control device according to the present invention can also be applied to a crawler crane or a tower crane. Configuration of Mobile Crane First, the configuration of the mobile crane will be described with reference to FIG. 2. As illustrated in FIG. 2, a rough terrain crane 1 of the present embodiment includes a vehicle body 10 serving as a main body portion of a vehicle having a traveling function, outriggers 11 provided at four corners of the vehicle body 10, a turning table 12 attached to the vehicle body 10 so as to be hor