Session: 09-05-03 Wave Energy: Mooring and Control

Submission Number: 157552

Position Estimation of a Wave Energy Converter Using Limited Sensor Data 

Advanced control systems for wave energy converters (WECs), such as the model predictive control or reinforcement learning, require precise real-time estimation of the buoy's position (surge, sway, and heave) and orientation (roll, pitch, and yaw). For WECs operating below the water surface, Global Navigation Satellite System data is unavailable for accurate position tracking, necessitating reliance on limited sensor measurements. One such WEC is the CETO system, which features a fully submerged buoy tethered to the seafloor by three mooring lines. The system is equipped with an inertial measurement unit (IMU) to track the buoy's spatial orientation, along with three encoders that measure the rotation of the shaft in the rotary power take-off, which can be correlated with the extension of each mooring line. However, in a full-scale setup, the IMU may not accurately measure the yaw angle due to magnetic interference from the power take-off electrical equipment. This paper presents an algorithm for estimating the position of the CETO device in the open ocean using limited sensor data. The methodology, adapted from cable robotics, is validated through numerical simulations and tank testing. Additionally, the paper offers recommendations on how incorporating additional sensors and measurements can improve the accuracy of state estimation for the WEC.

Presenting Author: Nataliia Sergiienko University of Adelaide

Presenting Author Biography: Dr Nataliia Sergiienko is a Senior Lecturer in the School of Electrical and Mechanical Engineering at the University of Adelaide, Australia. Nataliia received her Bachelor and Master degree in Aerospace engineering from the National Technical University of Ukraine, in 2005 and 2007 respectively. Between 2007 and 2012, Nataliia worked as a Modelling, Simulation and Analysis Engineer for the US-based company Innalabs Ltd developing high-precision inertial navigation and orientation systems for aerospace and marine applications. In 2018, Nataliia received her Ph.D. degree in Mechanical Engineering from the University of Adelaide, Australia. Nataliia’s current research focus is on wave energy converters and floating offshore wind platforms. Since 2023, Dr Sergiienko has been an Australia Research Council Industry Fellow working on deployment-ready control systems for the wave energy industry.