Offshore crane heave compensation control system and method using visual ranging

Patent metadata

Field	Value
Publication number	US-10843904-B2
Application number	US-201616064458-A
Country	US
Kind code	B2
Filing date	Dec 22, 2016
Priority date	Dec 22, 2015
Publication date	Nov 24, 2020
Grant date	Nov 24, 2020

Abstract

Provided is an offshore crane heave compensation control system and method using video rangefinding to achieve heave compensation in a directly driven pump-controlled electro-hydraulic heave compensator. The heave compensation and the heave compensator are applicable for special operation and control requirements on a fixed offshore platform and allow the crane to achieve steady lifting of a load away from or lowering of a load on to a supply vessel without being influenced by the motion of the supply vessel caused by ocean currents, ocean winds, or ocean waves. Also provided is a test platform for the offshore crane heave compensation control system using video rangefinding. The test platform provides a realistic simulation for all lifting and lowering processes of an offshore platform crane in offshore environments to study the motion control of the provided system.

First claim

What is claimed is:

1. An heave compensation control system using visual ranging for an offshore crane, comprising:
a detecting device,
a controlling device and
an actuating device,
the heave compensation control system is configured to achieve heave motion compensation automatically while the offshore crane is loading down and up cargo to a supply vessel, by adding a movement with the same direction and same amplitude to the supply vessel;
wherein: the detecting device is configured to detect a three-dimensional position information of the supply vessel using a visual ranging method, and transmit the detected parameters of three-dimensional position information to the controlling device,
the controlling device is configured to control the actuating device to achieve heave compensation movement automatically while the offshore crane is loading down and up the cargo to the supply vessel, by adding the movement with the same direction and amplitude to the supply vessel;
the offshore crane is positioned on a fixed offshore platform;
the three-dimensional position information means displacement, velocity and acceleration information in various directions which is referred to a rectangular coordinate system including the heave direction and the three-dimensional attitude of the supply vessel; and
the movement with the same amplitude and same direction means the supply vessel moves along with a periodic motion of the ocean waves with the same amplitude and same direction.

2. The heave compensation control system of claim 1 , wherein: during a loading up stage, the detecting device is configured detect heave motion information of the supply vessel using the visual ranging method, and the controlling device is configured to compute velocity and acceleration information of the supply vessel;
by adding the movement with the same amplitude and same direction to the supply vessel heave motion, the actuating device is configured to perform active heave motion compensation and choose a right time for loading up, so as to avoid impact loads of crane wire ropes.

3. The heave compensation control system of claim 1 , wherein: during a loading down stage, the detecting device is configured to detect the three-dimensional position information of the supply vessel using the visual ranging method;
under the control of the controlling device, the actuating device is configured to add the movement with the same amplitude and same direction to the supply vessel during the loading down stage, to ensure that the cargo is down to a vessel deck of the supply vessel at a relative setting speed;
the actuating device is further configured to judge attitude information of the supply vessel and choose a right time for loading down, so as to load down the cargo steadily.

4. The heave compensation control system of claim 1 , wherein: the actuating device is a direct pump control electro-hydraulic heave compensation device ( 3 ) comprising a servo motor driver ( 4 ), a rotation speed sensor ( 5 ), a displacement sensor ( 7 ), and at least three pressure sensors ( 6 );
the servo motor driver ( 4 ) is configured to drive the direct pump control electro-hydraulic heave compensation device ( 3 );
the rotation speed sensor ( 5 ), the displacement sensor ( 7 ), and the at least three pressure sensors ( 6 ) are configured to collect operating parameters of the direct pump control electro-hydraulic heave compensation device ( 3 ) and feed the collected operating parameters back to the controlling device for achieving a closed-loop control of the direct pump control electro-hydraulic heave compensation device ( 3 ), in order to load down and up the load steadily and stably.

5. The heave compensation control system of claim 4 , wherein: the direct pump control electro-hydraulic heave compensation device ( 3 ) comprises the servo motor driver ( 4 ), a servo motor ( 16 ), a two-way hydraulic pump ( 17 ), an accumulator ( 13 ), a quick connector ( 14 ), two overflow valves ( 15 ), a single rod hydraulic cylinder ( 11 ), a movable pulley ( 9 ), a static pulley ( 10 ), the at least three pressure sensors ( 6 ), the rotation speed sensor ( 5 ), and the displacement sensor ( 7 );
the servo motor driver ( 4 ) is configured to drive the servo motor ( 16 ) and therefore rotate the two-way hydraulic pump ( 17 );
two output terminals of the two-way hydraulic pump ( 17 ) are connected to a rod chamber and a rodless chamber of the single rod hydraulic cylinder ( 11 ) respectively through a hydraulic pipeline;
two overflow valves, which are oppositely arranged, are connected in parallel between the two output terminals of the two-way hydraulic pump ( 17 );
the servo motor ( 16 ) is connected to the rotation speed sensor ( 5 );
the rotation speed sensor ( 5 ), the displacement sensor ( 7 ), the servo motor driver ( 4 ), and the at least three pressure sensors ( 6 ) are respectively connected to the controlling device which is a control computer ( 1 );
the movable pulley ( 9 ) is connected to a piston rod of the single rod hydraulic cylinder ( 11 );
the static pulley ( 10 ) is connected to a bottom of the single rod hydraulic cylinder ( 11 );
the displacement sensor ( 7 ) is installed in the single rod hydraulic cylinder ( 11 ).

6. The heave compensation control system of claim 5 , wherein: the servo motor driver ( 4 ), the servo motor ( 16 ), the two-way hydraulic pump ( 17 ), the accumulator ( 13 ), the quick connector ( 14 ), the two overflow valves ( 15 ), the single rod hydraulic cylinder ( 11 ), the movable pulley ( 9 ), the static pulley ( 10 ), the at least three pressure sensors ( 6 ), the rotation speed sensor ( 5 ), and displacement sensor ( 7 ) are integrated into an autonomous device.

7. The heave compensation control system of claim 5 , wherein: the movable pulley ( 9 ), the piston rod of the single rod hydraulic cylinder ( 11 ) and the static pulley ( 10 ) of the direct pump control electro-hydraulic heave compensation device ( 3 ) are located on the same axis.

8. The heave compensation control system of claim 5 , wherein: after a first way of the accumulator ( 13 ) of the direct pump control electro-hydraulic heave compensation device ( 3 ) is connected to a first terminal of the two pilot operated check valves ( 18 ) which are oppositely arranged, a second terminal of the two pilot operated check valves ( 18 ) is connected in parallel between the two terminals of the two-way hydraulic pump ( 17 ).

9. The heave compensation control system of claim 5 , wherein: the accumulator ( 13 ) is divided into three ways, the three ways comprises the first way, a second way and a third way; wherein the first way is connected to the rod chamber of the single rod hydraulic cylinder ( 11 ), the second way is connected to the quick connector ( 14 ), and the third way is connected to a first pressure sensor ( 6 ) of the at least three pressure sensors;
the at least three pressure sensors at least comprises the first pressure sensor, a second pressure sensor and a third pressure sensor; wherein the two output terminals of the two-way hydraulic pump ( 17 ) are respectively connected to the second pressure sensor ( 6 ) and the third pressure sensor ( 6 ).

10. The heave compensation control system of claim 1 , wherein:
the controlling device is the control computer ( 1 ),
the detecting device is an industrial camera ( 2 ), and
the actuating device is a direct pump control electro-hydraulic heave compensation device ( 3 );
the industrial camera ( 2 ) and the direct pump control electro-hydraulic heave compensation device ( 3 ) are connected to the control computer ( 1 ) via electrical connection wiring ( 8 ) respectively;
the industrial camera ( 2 ) and the

Assignees

• Univ Zhejiang

Inventors

• Gong Guofang
• Zhang Yakun
• Wu Weiqiang
• Liao Xiangping
• Yang Huayong

Classifications

• F15B2211/50527

  using cross-pressure relief valves · CPC title

• F15B2211/855

  Testing of fluid pressure systems · CPC title

• F15B2211/633

  representing a state of the prime mover, e.g. torque or rotational speed · CPC title

• F15B7/006

  Rotary pump input · CPC title

• F15B2211/6306

  representing a pressure · CPC title