DE2818569A1 - Crane control system for ship cargo handling - has optical and photoelectric system ensuring handling of heavily rocking ship cargo - Google Patents

Abstract

The crane lifting system is used for lifting loads from floating ships or barges. Loads are picked up also when the ship is rocked by high waves. The lifting position for the load is observed along x, y coordinate axes by an optical signal generator and receiver in the crane arm. A reflector is fitted on the load carrying hook. The transmitter and the receiver are held in a damped suspended pendulum element which has a sliding feature for correction of wind loads. A tachogenerator is used for holding the load carrying rope in tension.

Description

Crane control for picking up relative to the crane

moving loads.

The invention describes an arrangement and a method which it makes it possible to use a crane to pick up loads that are not in it.

move in a predictable manner relative to the crane, so that after the Unwanted pendulum movements of the load do not occur.

State of the art There are arrangements and methods in particular for Taking up loads from floating ships is known, with the vertical movement of the ship detected by an electro-mechanical transducer and thus the cable winch of the crane can be controlled.

D3P 1250086 OS 1431 124 These known methods and arrangements fail, however, in cases where it is necessary, in violently agitated seas Pick up a load from a ship. This is especially the case when from a Oil rig is to be lifted from a ship from loads and the wind force is greater than 4.

W5e e in Fig. 1 da @, becomes the pick-up point due to the swell P of the load is constantly changing in all three spatial coordinates. Will the load in any If the position is raised, pendulum oscillations of the load occur, causing damage on the load on the ship or the drill rig.

As a result, the economic operation of 3ohrir.seln is severely hindered.

The invention has set itself the task, even in rough seas to allow the load to be picked up. The arrangement according to the invention is as follows described and sketched in more detail @@ Fig. 2) According to the principle of Invention (Fig. 2) first loosely attach the crane rope with the load hook LH to the lifting eye be hooked.

The crane rope is stretched d-nn by the crane winch so that constantly a force which corresponds approximately to the 10th part of the weight of the load the crane rope works.

F # 1 @ 1 @ M @ @ F - Seilk @@ ft 5 0 5 M @ = load mass g = acceleration due to gravity This makes the rope independent of the movements of the load @ P {x (t), y (t), z (t) 1 kept largely taut.

The following arrangement is now used to detect the suitable lifting position.

A cushioned pendulum body PK is attached to the crane boom. This pendulum body PK contains an optical transmitter (S) and receiver (E). That The Send @ r's signal is in a narrow cone in the axial direction of the pendulum body PK sent out.

A retroreflector R is located on the upper side of the load hook L, which is moved with the load.

The signal from the receiver can now be used for control in a simple manner the lifting process of the load via the control of the @@ anwinde.

If the wind is weak but the sea is rough, the correct lifting position will be then reached when the ship moves vertically against the sea placed the boom. The vertical direction is given by the pendulum, @o dap the detector signal from receiver E shows exactly the lift-off position.

With very strong movements of the ship in the t-4 axis (high swell) it is advisable to raise the load at the moment the ship is level begins to lower again. This moment can be in a known manner about a Tachometer generator on the crane winch.

In this case, the withdrawal condition occurs when the recipient E has a signal and at the same time the tachometer generator has an upper reversal point Load reports.

Of course, in order to achieve this status, the ship must Maneuver with the load several times, but this is the only way to safely lift the load possible.

With greater wind strengths, lateral forces occur in x and through the wind y on the load, so that the vertical position for a pendulum-free lifting of the load is not cheap under the crane boom. For this case, the pendulum body protrudes PK a retractable wind vane WF, so that depending on the current wind strength ud the load area a suitable offset α (see Fig. 1) of the measuring axis from the Adjusts vertical.

The pendulum body itself and its elements are explained in more detail in Fig. 3. The assembly of the retroreflector is shown in Fig. 4.

Of course, the arrangement described can be reduced in many ways. and supplemented.

In addition to the lax measurement, optical distance and Speedometer for better determination of the appropriate take-off time can be used.

To avoid interference, provision is also made for the transmission signal Modulate za so that extraneous light reflections do not affect the receiver.

Instead of the damping arrangement shown in Fig. 3, of course a liquid damping with adjustable effect find use.

A built-in heater H prevents the beating and freezing of the Optics at low temperatures. Furthermore, there are the signal cones from the transmitter and receiver Can be changed via covers and adjusting screws to suit the respective working conditions (Boom height above load). Conductive diodes are used as transmitter elements or diode lasers, semiconductor diodes are also used as receivers.

Claims (8)

Claims 1) arrangement and method for controlling the crane winch when Lifting loads from a system moved relative to the crane using conventional Soeuerbaren cranes and Eranwir denmarked as a result of the lifting position for the load in the x and y coordinates through an optical signal transmitter and receiver on the boom and a retroreflector on the load hook, which is loosely attached to the load is, is determined, with the transmitter and receiver in a cushioned suspension There are pendulum bodies, which have a movable wind vane to correct wind loads wearing. 2) Device and method according to claim 1 characterized marked @ et, c-- with the load rope held taut on the tachometer generator of the cable winch, a signal derived from w. D, (z signal) which with the signal for the x, y position according to the arrangement is combined according to claim 1 1 3) Anordnun @ according to claims 1 un.l 2 characterized in that the signal light bundle of sending and receiving. by adjusting devices for the position of the light transmitter and receivers uld / or ulendenvorrichtungen are changeable. 4) Arrangement according to claims 1 to 3, characterized in that Using a rope force measuring device, the crane winch on the rope constantly has a force of 0.05 to Let act 0.3 times the load weight, so that regardless of the movements of the Last dqs rope remains taut almost all the time. 5) Arrangement according to claims 1 to 4, characterized in that on the outside des C ~ atcE a one Slala is attached, which shows the resulting angle of deflection from the vertical for different positions of the wind vane depending on the wind strength. 6) Arrangement according to claims 1 to 5, characterized in that the creation of the mentioned wind vane also via a remote control mechanism (motor gear) can be done. 7) Arrangement according to claims 1 to 6, characterized in that dap the damping of the pendulum body PK can be changed. 8) Arrangement according to claims 1 to 7, characterized in that dap Heating elements in the pendulum body PK prevent fogging up with moisture or ice.