An Innovative FPGA-Based Control Approach for Wave Generation Systems Developed by Balıkesir University Researchers

A scientific study conducted at Balıkesir University has introduced an innovative approach to the precise and real-time control of hydraulically actuated wave generation systems. The research was carried out by Prof. Dr. Ersin Akyüz, Prof. Dr. Sabri Bıçakçı, Asst. Prof. Dr. Tuğçe Tepebaşı, and Asst. Prof. Dr. Batın Demircan , researchers at the Renewable Energy Research, Development and Application Center of Balıkesir University. The study developed an FPGA (Field-Programmable Gate Array) based, two-layer cascade control architecture to generate regular water waves under laboratory conditions and maintain wave heights at desired reference values. The research focuses on achieving more precise and reliable wave generation by mitigating the effects of hydrodynamic loads, nonlinear system behavior, and delays caused by wave propagation, which are commonly encountered in conventional wave generation methods.

Unlike conventional approaches that control only the position of the hydraulic piston, the study developed an integrated control strategy that directly utilizes the actual wave height measured in the wave channel as feedback. In the inner control layer of the proposed architecture, the position of the hydraulic servo cylinder is regulated using Proportional-Integral (PI) and Takagi–Sugeno (T–S) fuzzy logic controllers with a 1-millisecond control cycle. In the outer control layer, the measured wave height is evaluated with a 20-millisecond control cycle, allowing the piston position reference to be updated in real time. Three different metaheuristic optimization algorithms were employed to determine the control parameters, with the aim of improving the system's tracking performance.

One of the distinguishing features of the research is the optimization of the developed fuzzy logic-based control algorithm in terms of FPGA hardware resource utilization. Within this framework, a similarity-based rule simplification approach was employed to reduce the number of consequent parameters in the Takagi–Sugeno controller from 27 to 9. This optimization resulted in a 66.7% reduction in FPGA execution time and a 62.5% reduction in digital signal processing (DSP) resource utilization . While achieving these improvements, the change in position tracking error remained at only 2.2–2.3%, demonstrating that the proposed approach can significantly improve computational efficiency while largely preserving control performance. Experimental results demonstrated that the developed system could achieve highly accurate piston position tracking and stable steady-state wave height control. The findings were further validated through Fast Fourier Transform (FFT) analyses.

Based on the findings, the study experimentally demonstrates the advantages of combining real-time feedback with FPGA-based control technologies in hydraulically actuated wave generation systems. The developed approach has the potential to contribute to the generation of more precise, repeatable, and reliable wave conditions in experimental wave channels, particularly those used in coastal and ocean engineering research. Furthermore, the study provides a methodological reference for various mechatronic and industrial automation applications in terms of high-speed embedded control systems, fuzzy logic-based controller design, and efficient utilization of hardware resources.