## 1 Introduction  
Increasing the generation of energy using renewable sources is a key political measure already adopted by both developed and developing countries. In this context, wind energy is considered a technology with huge possibilities for industrial exploitation, maturity, and large-scale integration into the power systems [1, 2]. In this sense, offshore (marine) wind farms feature advantages over onshore (land) facilities with regard to the power obtained and environmental impact. Given that appropriate sites on the continental shelf are limited, placing wind turbines in deep water turns up as a feasible option, as different floater solutions have demonstrated, each with its own pros and cons [3]. Among these floating structures, the installation of wind turbines on semi-submersible platforms is a promising alternative, as studied in [4], which allows secondary uses such as aquaculture or tidal energy. Non-fixed foundations have attracted a lot of attention, particularly from Europe [5]. The worldwide wind energy installed capacity was forecasted to reach 217 GW by 2020 and 414 GW by 2030 [6], but this moderate scenario has been surpassed by far, as installed wind energy facilities accounted for 563 GW in 2018, 23 GW of them corresponding to offshore facilities [7]. As an example, in the case of Spain, 20.9% of the electricity consumed in 2019 came from wind generation [8]. At the European level, offshore facilities have arisen from 5% of newly installed wind turbine capacity in 2009 to over 23% in 2019 [9],and offshore wind farms are considered the most profitable renewable energy source in Europe [10]. However, the massive integration of the electricity produced in renewable facilities into power systems brings the need to employ controllers to adapt the production of electric energy with two purposes: increasing the return on the investments and avoiding harm to the electrical grid they are connected to. This is particularly relevant in the case of wind energy because of its significant participation in the energy mix [11]. The most frequent technique currently used to implement this regulation is the simultaneous control of both the generator torque, using MPPT (Maximum Power Point Tracking) algorithms, and the angle of attack of the blades or pitch [12]. While the control of the first one is well-established, there is not a universally accepted solution to control the angle of attack of the blades, and several approaches can be found in the literature. As a reference, in [13], the control techniques are classified into four groups: optimal TSR (Tip to Speed Ratio) search, closed-loop power control, ascending search control, and hybrid control. The dynamics of a floating wind turbine are different from that of an onshore wind turbine [14]. In addition to the common elements, which can be described using aerodynamic, mechanical, and electrical models, the floating platform itself and its mooring have their own dynamics, being under the effects of hydrodynamics, waves, currents, tides, and ice. The resulting system is nonlinear, with internal variables strongly coupled and difficult to model [15]. Even with a model, the dynamics of the combined system may produce notable differences between the measured wind and the effective wind, i.e., the wind on the surface of the blades, particularly in the case of strong winds in a turbulent regime. The behavior of the controller has a strong impact in these cases, both on the energy harvested and on the safety of the facility. Thus, offshore wind turbine operators tend to be conservative in the adoption of pitch controllers to substitute the industry-standard PID [14]. However, operators have expert knowledge of the desired behavior of offshore wind turbines. A control strategy able to capture this desired behavior can be an effective option to improve controllers in actual wind turbines. This work proposes a novel fuzzy logic pitch controller that adjusts the output of an improved standard PI controller.