US 10,150,653 B2Granted

Method for reducing dynamic loads of cranes

AssigneeNational Oilwell Varco Norway AS

InventorAge Kyllingstad

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Abstract

A method and related device for reducing resonant vibrations and dynamic loads of cranes, where vertical motion of a pay load is controlled by a boom winch and a hoist winch. In an embodiment, the method includes determining resonance frequencies of the crane boom and pay load from inertia data of the boom and stiffness on at least the boom and hoist ropes, the resonance frequencies including a first frequency and a lower second frequency. In addition, the method includes automatically modifying the motion of the boom winch or the hoist winch to induce a damping inducing winch motion in the boom or hoist winch, by tuning a proportional integral (PI)-type boom winch speed controller or a PI-type hoist winch speed controller. The boom winch speed controller is tuned to absorb energy at the second frequency, the hoist winch speed controller is tuned to absorb energy at the first frequency.

Claims9

Dependent claims

A device for reducing resonant vibrations and dynamic loads of cranes, the device comprising:

a boom winch configured to control a luffing motion of a pivoting boom;
and
a hoist winch configured to control a vertical distance between a boom tip and a pay load of the crane;
a boom winch speed controller coupled to the boom winch;
and
a hoist winch speed controller coupled to the hoist winch;
wherein the device is configured to acquire resonance frequencies of a coupling of the pivoting boom and the pay load from at least inertia data of the pivoting boom and stiffness data on at least a boom rope coupled to the boom winch and a hoist rope coupled to the hoist winch, the resonance frequencies including a first resonance frequency and a second resonance frequency, the second resonance frequency being lower than the first resonance frequency;
wherein the boom winch speed controller or the hoist winch speed controller is configured to automatically modify a motion of the boom winch or a motion of the hoist winch, respectively, to induce a damping inducing winch motion;
wherein the boom winch speed controller comprises a proportional integral (PI)-type speed controller that is tuned to absorb vibration energy at the second resonance frequency;
and
wherein the hoist winch speed controller comprises a PI-type speed controller that is tuned to absorb vibration energy at the first resonance frequency.

8 more elements

A method for reducing resonant vibrations and dynamic loads of cranes, wherein a vertical motion of a pay load is controlled by a boom winch controlling a luffing motion of a pivoting boom and a hoist winch controlling a vertical distance between a boom tip and the pay load, the method comprising:

determining resonance frequencies of a coupling of the pivoting boom and the pay load from at least from inertia data of the pivoting boom and stiffness data on at least a boom rope coupled to the boom winch and a hoist rope coupled to the hoist winch, the resonance frequencies including a first resonance frequency and a second resonance frequency, the second resonance frequency being lower than the first resonance frequency;
and
automatically modifying a motion of the boom winch or a motion of the hoist winch to induce a damping inducing winch motion in the boom winch or hoist winch, respectively, by tuning a proportional integral (PI)-type boom winch speed controller coupled the boom winch or a PI-type hoist winch speed controller coupled to the hoist winch;
wherein the boom winch speed controller is tuned to absorb vibration energy at the second resonance frequency;
and
wherein the hoist winch speed controller is tuned to absorb vibration energy at the first resonance frequency.

3 more elements

Dependencies are inferred from the claim text.

Facts

Application: 15/069,254Filed 14 Mar 2016 · continuation
Priority: NO 2010043524 Mar 2010
Published: US 2016/0194183 A17 Jul 2016
Granted: 11 Dec 2018
Term ends: Not estimatedThe source records don’t support an estimate.

Classification10 codes

B66C 13/06
Auxiliary devices for controlling movements of suspended loads, or preventing cable slack: for minimising or preventing longitudinal or transverse…
B66C 13/04
Other constructional features or details: auxiliary devices for controlling movements of suspended loads, or preventing cable slack
B66C 13/066
For minimising or preventing longitudinal or transverse swinging of loads: for minimising vibration of a boom
B66D 1/52
Automatic: for varying rope or cable tension, e.g. when recovering craft from water

Family

PCT/NO2011/000087Parent of this continuation · filed 17 Mar 2011
US 2016/0194183 A1Pre-grant publication · published 7 Jul 2016
Application13/636,964Parent of this continuation
US 2013/0213919 A1Published application
US 10,150,653 B2This patent

From the US filing history. Foreign family members aren’t listed.