A robotized 6-DOF dry test rig for wave power

Abstract

Wave power has the potential to contribute significantly to sustainability by reducing our global dependence on fossil fuels. Due to harsh conditions and high costs associated with offshore testing, lab experiments are favourable for resource-efficient validation and optimization in developing Wave Energy Converter (WEC) technologies. The limited scale and availability of existing wave tanks, and the limited flexibility of existing dry test rigs does however put significant restraints on such experiments. In this paper we introduce an alternative novel robotized dry test rig concept for wave power, evaluate its performance and discuss its potential. A full-scale robotized dry test rig demonstrator is constructed and used for experiments with a WEC prototype device. High motion flexibility and accuracy is thereby validated, also for repeating recorded wave and buoy motions. Compared to other dry test rigs, no special components were used and the motion trajectories were defined in full 6-Degrees-Of-Freedom. Two real-time hydrodynamic motion response methods are also demonstrated in the test rig, enabling emulation of actual offshore operation as well as development of advanced WEC control strategies. With a larger industrial robot manipulator, the introduced test rig concept could achieve realistic scaled force and power experiments with most point absorber WECs.