## 5 Conclusions  
In this study, we analyze and compare the real improvements that can be achieved with different types of adaptive controllers with the azimuth offset and different controller gains in different IPC schemes tested on a 15 MW wind turbine model, which is simulated with OpenFAST v3.5 software. The problem of controller parameter tuning is addressed as  
Figure 9: Frequency domain response of the out-of-plane blade moment and pitch signal for blade 1 using Fourier spectra. an optimization where the fatigue load on the blade is minimized according to the DEL and solved by genetic algorithms. The proposed IPC schemes are implemented as an adaptive block where the gains and azimuth offset have scheduled values according to the mean value of the filtered moments of the blades. In addition, the IPC schemes are combined with a pre-defined CPC. Several simulations are performed to compare the proposed IPC schemes. Specifically, we analyze the impact of three aspects: using proportional or integral controllers, using two identical or two different gains in the decentralized controllers of the IPC, and including or not including the azimuth offset in the reverse MBC transform. There is previous research on the impact of including the offset or not in the control; however, we have not found any works in the literature that simultaneously analyze the impact of the three factors considered here on control performance. The simulation findings show that the proposed methodology is robust and adaptable to wind conditions and that it may be utilized to improve the structural integrity of blade wind turbines without sacrificing power generation efficiency. The IPC schemes proposed in this work significantly decrease the out-of-plane (OoP) blade moments when compared to not using IPC but at the cost of greater pitch actuator effort. A comparison of the proposed IPC schemes demonstrates that:  
* The optimal IPC solution with proportional controllers (with or without the azimuth offset) produces a similar reduction in DEL values as the optimal solution of IPC with integral controllers without the azimuth offset; however, the proportional controllers produce higher pitch signal activity. * The IPC schemes with integral controllers and the azimuth offset outperform the other schemes because they achieve the lowest DEL values of the OoP blade moments with minor pitch activity. * Using different gains in the controllers of the IPC does not provide significant improvements; however, it requires an additional tuning parameter in the optimization procedure and, consequently, a higher computational cost. Therefore, we can conclude that the most advantageous IPC scheme is the IPC_I1\(\Downarrow\) case--that is, the IPC with two optimal identical integral controllers plus an optimal azimuth offset--because it surpasses the response of the other optimized IPC schemes and requires only two parameters to be tuned. This IPC scheme can achieve an additional reduction of approximately 10% in the DEL value of the OoP blade moments with the lowest pitch actuator effort in comparison with the other IPC schemes. Future research is required to deal with the trade-off between the two main conflicting objectives in IPC: blade load reduction and pitch actuator effort. Future work will also address the analysis of more advanced controllers in the IPC scheme, such as multi-loop PI or PID controllers, H\({}_{\infty}\) control, and decoupling control. Conceptualization, M.L., S.P.M. and J.-W.v.W. ; methodology, M.L. and S.P.M. ; software, M.L. ; validation, S.P.M., J.-W.v.W., F.V. and J.G. ; formal analysis, M.L. ; investigation, M.L. and J.G. ; resources, F.V. and J.G. ; data curation, J.G. ; writing--original draft preparation, J.G. ; writing--review and editing, J.G., S.P.M., J.-W.v.W. and M.L. ; visualization, J.G. ; supervision, J.-W.v.W. and F.V. ; project administration, J.G. ; funding acquisition, J.G. and F.V. All authors have read and agreed to the published version of the manuscript.