Advanced vibration control strategies for Electro-Hydraulic testing systems focus on sinusoidal Swept-Frequency techniques

This paper presents an advanced investigation into vibration control strategies for electro-hydraulic testing systems, with a specific emphasis on sinusoidal swept-frequency techniques. Electro-hydraulic shaking tables (EHSTs) are critical in replicating the dynamic conditions for applications in civil engineering, automotive testing, and seismic assessments. Although widely used, the nonlinear dynamics of EHSTs—characterised by factors such as oil flow friction and dead zones—frequently cause distortion in response signals, particularly during high-frequency vibration testing, thereby limiting system performance. To address these challenges, this study proposes a dual approach. The first method employs offline control through system identification coupled with iterative correction algorithms, while the second uses real-time predictive control based on the system’s frequency response function. A novel composite control strategy is developed, integrating the strengths of both approaches to achieve improved amplitude and phase compensation, thus enhancing both robustness and accuracy in vibration control. The proposed strategy is validated through both simulations and experimental testing on a six-degree-of-freedom electro-hydraulic shaking table, demonstrating significant improvements in phase lag reduction and amplitude tracking, particularly at higher frequencies. This control approach provides an optimised solution for precise vibration control in complex engineering applications.