Active Vibration Control of Piezoelectric Beams under Uncertain Delay via a DDR-PPO Approach
摘要
This study aims to develop a robust vibration control strategy for piezoelectric cantilever beams to address the instability and performance degradation caused by uncertain time delays.
MethodsA novel control approach is proposed using Proximal Policy Optimization (PPO) integrated with a Delay Domain Randomization (DDR) mechanism. By implementing dynamic random sampling within a predefined delay domain during the reinforcement learning training process, the PPO agent learns a generalized control law. A discrete state-space model of the piezoelectric beam is established based on Euler-Bernoulli beam theory and the modal superposition method, with key physical parameters identified through experimental characterization.
ResultsComparative simulations indicate that while standard PPO controllers outperform conventional proportional-derivative (PD) controllers in delayed environments, agents trained at a single fixed delay suffer from overfitting and limited generalization. Experimental validation demonstrates that the proposed DDR-PPO controller achieves an approximate 20–30 dB reduction in the second-order mode vibration peak compared to the fixed-delay-trained PPO. Furthermore, the DDR mechanism significantly extends the allowable time-delay range while maintaining system stability.
ConclusionThe integration of Delay Domain Randomization with PPO significantly enhances the robustness of active vibration control systems against uncertain delays. The proposed DDR-PPO controller provides an effective and generalized solution for structural vibration suppression in engineering applications where communication or processing delays are prevalent and variable.