The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Aug. 07, 2012
Filed:
May. 20, 2009
Klaus Schneider, Hergatz, DE;
Oliver Sawodny, Stuttgart, DE;
Joerg Neupert, Korntal-Muenchingen, DE;
Tobias Mahl, Stuttgart, DE;
Sebastian Kuchler, Boblingen, DE;
Klaus Schneider, Hergatz, DE;
Oliver Sawodny, Stuttgart, DE;
Joerg Neupert, Korntal-Muenchingen, DE;
Tobias Mahl, Stuttgart, DE;
Sebastian Kuchler, Boblingen, DE;
Liebherr-Werk Nenzing GmbH, Nenzing, AT;
Abstract
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.