Active vibration control enabled by intelligent excitation adaptability for frequency-variable excitations

Active vibration control (AVC) is a well-validated solution for vibration suppression in stable environments with specific frequency ranges. However, maintaining its high performance under variable and unpredictable excitation conditions remains a significant challenge. This article develops an intelligent excitation-adaptive active vibration control (IEA-AVC) method to achieve optimal control of structures under frequency-variable excitations. The method integrates conventional AVC techniques with real-time identification of excitation frequency and autonomous adaptation of feedback gains. A typical IEA-AVC system employs multiple complementary control gain settings featuring staggered resonance characteristics and switches among them as required. A general linear multi-degree-of-freedom dynamic model is established, and a model-based algorithm is developed for real-time identification of variable harmonic excitation frequencies using only acceleration measurements. Experiments confirm that the proposed algorithm rapidly (min. to 95 ms) and accurately tracks time-varying excitation frequencies, enabling real-time autonomous switching between preset control gain settings. Based on this validated architecture, theoretical analyses and simulations are conducted to evaluate system performance under different gain settings, and corresponding customized control schemes are consequently proposed. The results show that the resonance at each modal order is effectively avoided, leading to significantly enhanced vibration suppression.