A control strategy for combined DP station keeping and active roll reduction

Abstract

Dynamic positioning (DP) systems are used for station keeping during offshore operations. The safety and operability of several offshore operations can be increased when the roll motion is actively controlled, especially in beam seas. We propose a novel control strategy for combined roll motion control and station keeping, using no additional hardware than the installed DP thrusters. The control strategy is applied to an offshore construction vessel and the performance is demonstrated by time domain simulations. The DP footprint is compared to a conventional dynamic positioning control model. The proposed control model enables active roll reduction while the station keeping performance remains unaffected. The code has been made open source and is available on https://github.com/pwellens/3dp.git.