Author(s)

Ke Fan, Yanjun Liu

Corresponding Author

ABSTRACT

Wave Energy Converters (WEC) can achieve high energy extraction efficiency by optimal control of the PTO system. Optimal controller should achieve high tracking performance and compensate the time delay between sensors and actuators. The controller needs a predictive trajectory as the input reference. On the other hand, due to the variable sea condition and sensor noise, the heave signal measured by IMU cannot be applied to the controller directly. To extract the accurate heave motion from the signal in presence of uncertainties and sensor noise as well as compensate the time delay, a novel heave motion predictor is designed in this paper. Firstly, a heave motion dynamic proximation is established by analysis of the spectrum of IMU signal. Then the direct adaptive robust observer is applied to estimate the parameters of the heave motion dynamic proximation. Finally, the predictive trajectory will be produced by the predictive model based on the dynamic proximation. Simulation results indicate that the proposed heave motion predictor has high heave motion predict precision and robustness to uncertainties and sensor noise.

KEYWORDS

Wave Energy Converters; parameter estimation; direct adaptive robust observer; motion predicting