Liebherr-Werk Nenzing Gmbh

Joerg Neupert

Oliver Sawodny

Klaus Schneider

Eckard Arnold

Karl Lukas Knierim

Tobias Mahl

Sebastian Kuchler

Alexander Hildebrandt

The present invention relates to a crane for handling a load hanging on a load cable, comprising a slewing gear for rotating the crane, a luffing gear for luffing up the boom, and a hoisting gear for lowering or lifting the load hanging on the load cable, with a control unit for calculating the actuation of slewing gear, luffing gear and/or hoisting gear, wherein the calculation of the actuation commands for actuating slewing gear, luffing gear and/or hoisting gear is effected on the basis of a desired movement of the load indicated in Cartesian coordinates.

Crane for handling a load hanging on a load cable

The present invention represents a procedure for compensating the heave movement of offshore cranes. The dynamic model of the compensation actuator (hydraulically operated winch) and the load hanging on a rope are derived. Based on this model, a path-tracking control unit is developed. To compensate the movement of the ship/watercraft caused by waves, the heave movement is defined as a time-varying disturbance and is analyzed with respect to uncoupling conditions. With a model expansion, these conditions are satisfied, and an inversion-based uncoupling control law is formulated. To stabilize the system, an observer is used for reconstructing the unknown state by means of a force measurement. Furthermore, the compensation efficiency can be improved by predicting the heave movement. There is proposed a prediction method in which no ship/watercraft models or properties are required. The simulation and measurement results validate the heave compensation method.

Crane control with active heave compensation

A control system for a boom crane, having a tower and a boom pivotally attached to the tower, a first actuator for creating a luffing movement of the boom, a second actuator for rotating the tower, first means for determining the position rand/or velocity {dot over (r)}of the boom head by measurement, second means for determining the rotational angle &#x3c6;and/or the rotational velocity {dot over (&#x3c6;)}of the tower by measurement, the control system controlling the first actuator and the second actuator. In the control system of the present invention the acceleration of the load in the radial direction due to a rotation of the tower is compensated by a luffing movement of the boom in dependence on the rotational velocity {dot over (&#x3c6;)}of the tower determined by the second means. The present invention further comprises a boom crane having such a system.

Control system for a boom crane

The invention relates to a method for the transfer of a load hanging at a load rope of a crane or excavator comprising a slewing gear, a luffing mechanism and a hoisting gear comprising a computer-controlled regulator for the damping of the load oscillation which has a trajectory planner, a disturbance observer and a state regulator with a pre-control, wherein the working space is first fixed by selection of two points, with one of the two points being fixed as the destination point by direction presetting by means of the hand lever and with the nominal speeds for the slewing gear and the luffing mechanism being preset by the hand lever signals.

Growing community of inventors

Korntal-Muenchingen, Germany

Joerg Neupert