Modeling of an Electro-Hydraulic System for Wave Generation in a Wave Channel

This paper presents a black-box mathematical model of the electrohydraulic system controlling the wave generation structure in a wave channel under various operating conditions. For the position control of the system, NI-CRIO 9074 hardware and LabVIEW software were used. Open-loop position control experiments of the hydraulic cylinder were conducted using stimulus signals with different initial positions (0, 120, and 240 mm) and amplitudes. Data were recorded for different sampling times: 1 ms, 2 ms, 5 ms, and 10 ms. The recorded data were processed using the System Identification Toolbox (SIT) in MATLAB, and system models were developed in both continuous and discrete time domains using transfer function, state space, and AutoRegressive with eXogenous input (ARX) models. These models were compared and analyzed based on their fit rates to the training and test data. Among the system models with high compliance rates, the top three models were selected for further comparison using an additional test dataset. Based on this evaluation, the transfer function model (120 mm initial condition and 1 ms sampling time) type was identified as the best-performing model. This model was successfully integrated into the real-time control study, achieving effective controller performance.